Freezing plug generation propriety determination device, freezing plug generation propriety determination method, and program

Abstract

To determine whether a freezing plug can be generated within a desired time on the basis of a determined condition without actually generating the freezing plug.SOLUTION: A freezing plug generation propriety determination device acquires piping information being information on piping in which a freezing plug is generated inside by being cooled by a cooling object, initial liquid temperature information showing the temperature of a liquid in the piping before being cooled by the cooling object, atmospheric temperature information showing the temperature of air around the piping, heat source arrangement information showing an arrangement state of the heat source for supplying heat to the liquid, cooling object information being information on the cooling object, and allowable time information showing a time to be allowed to generate the freezing plug, calculates a coagulation heat value to be supplied to the liquid in the piping on the basis of the piping information, the initial liquid temperature information, the atmospheric temperature information, the heat source arrangement information, and the cooling object information, calculates a prediction time to generate the freezing plug with a predetermined length in the piping on the basis of the coagulation heat value, and determines whether to be able to generate the freezing plug on the basis of the prediction time and a time shown by the allowable time information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a device for determining whether a freeze plug can be generated, a method for determining whether a freeze plug can be generated, and a program. [Background technology]

[0002] In piping, water may need to be stopped when inspecting or repairing the inside of a certain section. In this case, if no valve is installed around the section, the water cannot be stopped using the valve. In such cases, the water in the piping is frozen using a cooling medium such as dry ice to create a frozen plug called an ice plug, thereby stopping the water (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-065281 A Summary of the Invention [Problem to be solved by the invention]

[0004] The conditions for generating ice plugs largely depend on the know-how of experts, but for example, Patent Document 1 discloses a technique for determining whether an ice plug is complete based on measurements obtained during the process of generating the ice plug, without relying on the know-how of experts. However, this technique is used in the process of actually generating ice plugs, and there is a problem in that it is not possible to determine whether an ice plug can be generated within a desired time based on the defined conditions before starting the task of generating the ice plug.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a freeze plug generation feasibility determination device, a freeze plug generation feasibility determination method, and a program that determine whether a freeze plug can be generated within a desired time based on specified conditions without actually generating a freeze plug. [Means for solving the problem]

[0006] In order to solve the above problem, the freeze plug generation possibility determination device of the present disclosure includes an input information acquisition unit that acquires piping information, which is information about a piping in which a freeze plug is generated by being cooled by a coolant, initial liquid temperature information indicating the temperature of the liquid in the piping before being cooled by the coolant, ambient temperature information indicating the temperature of the air surrounding the piping, heat source arrangement information indicating the arrangement state of a heat source that supplies heat to the liquid, coolant information, which is information about the coolant, and allowable time information indicating the time allowed for the generation of the freeze plug; a heat quantity calculation unit that calculates the amount of coagulation heat to be supplied to the liquid in the piping based on the piping information, the initial liquid temperature information, the ambient temperature information, the heat source arrangement information, and the coolant information; a predicted time calculation unit that calculates a predicted time for a predetermined length of the freeze plug to be generated in the pipe based on the coagulation heat; and a generation possibility determination unit that determines whether the freeze plug can be generated based on the predicted time and the time indicated by the allowable time information.

[0007] The method for determining whether a freeze plug can be generated according to the present disclosure includes the steps of acquiring piping information, which is information about a piping in which a freeze plug is generated by being cooled by a coolant, initial liquid temperature information indicating the temperature of the liquid in the piping before being cooled by the coolant, ambient temperature information indicating the temperature of the air surrounding the piping, heat source arrangement information indicating the arrangement state of a heat source supplying heat to the liquid, cooling material information, which is information about the cooling material, and allowable time information indicating the time allowed for the generation of the freeze plug, calculating the amount of heat of solidification to be supplied to the liquid in the piping based on the piping information, the initial liquid temperature information, the ambient temperature information, the heat source arrangement information, and the cooling material information, calculating a predicted time for the freeze plug of a predetermined length to be generated in the pipe based on the amount of heat of solidification, and determining whether the freeze plug can be generated based on the predicted time and the time indicated by the allowable time information.

[0008] The program of the present disclosure causes a computer to execute the steps of acquiring piping information, which is information about a piping in which a freeze plug is generated by being cooled by a coolant, initial liquid temperature information indicating the temperature of the liquid in the piping before being cooled by the coolant, ambient temperature information indicating the temperature of the air surrounding the piping, heat source arrangement information indicating the arrangement state of a heat source that supplies heat to the liquid, cooling material information, which is information about the cooling material, and allowable time information indicating the time allowed for the generation of the freeze plug, calculating the amount of solidification heat to be supplied to the liquid in the piping based on the piping information, the initial liquid temperature information, the ambient temperature information, the heat source arrangement information, and the cooling material information, calculating a predicted time for the freeze plug of a predetermined length to be generated in the pipe based on the amount of solidification heat, and determining whether the freeze plug can be generated based on the predicted time and the time indicated by the allowable time information. Effect of the Invention

[0009] According to the freeze plug generation feasibility determination device, freeze plug generation feasibility determination method, and program disclosed herein, it is possible to determine whether a freeze plug can be generated within a desired time based on specified conditions, without actually generating a freeze plug. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing an example of the configuration of a freeze plug generation possibility determination device according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram showing the amount of cooling and the amount of heat involved in the generation of ice plugs assumed in an embodiment of the present disclosure. [Diagram 3] 1A to 1C are diagrams illustrating examples of shapes of pipes to be processed in an embodiment of the present disclosure. [Figure 4] 10A to 10C are diagrams showing assumed shapes of pipes other than the shape of the pipes to be processed in the embodiment of the present disclosure. [Diagram 5] 1A and 1B are diagrams illustrating types of tables stored in a storage unit according to an embodiment of the present disclosure. [Figure 6] FIG. 13 is a diagram illustrating an example of a data format of a piping specification table according to an embodiment of the present disclosure. [Figure 7] FIG. 13 is a diagram illustrating an example of a data format of a cooling object table according to an embodiment of the present disclosure. [Figure 8] 1 is a flowchart (part 1) showing an example of the operation of a freeze plug generation possibility determination device according to an embodiment of the present disclosure. [Figure 9] 11 is a flowchart (part 2) showing an example of the operation of the device for determining whether or not a freeze plug can be generated according to an embodiment of the present disclosure. [Figure 10] 11 is a flowchart (part 3) showing an example of the operation of the device for determining whether or not a freeze plug can be generated according to an embodiment of the present disclosure. [Figure 11] 13 is a flowchart illustrating an example of the operation of a natural circulation heat input calculation unit according to an embodiment of the present disclosure. [Figure 12] FIG. 1 is a diagram showing natural circulation occurring in a horizontal single-pipe assumed in an embodiment of the present disclosure. [Figure 13]FIG. 1 is a diagram showing layers formed in the water due to natural circulation that occurs in a single horizontal pipe assumed in an embodiment of the present disclosure. [Figure 14] FIG. 2 is a diagram showing heating and cooling sections formed in the water inside the vertical single pipe by natural circulation assumed in an embodiment of the present disclosure. [Figure 15] FIG. 2 illustrates natural circulation occurring in a composite pipe as contemplated in an embodiment of the present disclosure. [Figure 16] 1A to 1C are diagrams illustrating a process of ice plug generation assumed in an embodiment of the present disclosure. [Figure 17] FIG. 1 is a schematic block diagram illustrating a configuration of a computer according to at least one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a freeze plug generation possibility determination device, a freeze plug generation possibility determination method, and a program according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the same or corresponding components in each drawing are designated by the same reference numerals and descriptions thereof will be omitted as appropriate.

[0012] (Overview of ice plug formation) 1 is a block diagram showing an example of the configuration of a frozen plug generation possibility determination device 1 according to an embodiment of the present disclosure. The frozen plug generation possibility determination device 1 determines whether or not it is possible to freeze water at a desired location in a pipe containing water therein using a cooling medium containing dry ice, for example, and generate an ice plug of ice that will become a frozen plug of a predetermined length within a desired time.

[0013] FIG. 2 is a cross-sectional view of the pipe 40, which is a hollow cylinder installed horizontally, cut along a vertical plane including the central axis of the pipe 40. FIG. 2 shows the amount of heat supplied and consumed in the pipe 40 and the water 50 present inside the pipe 40, and the amount of cooling supplied, during the process of ice plugs 51 being generated inside the pipe 40. For example, two cooling materials 70-1 and 70-2 called jackets are attached to the pipe 40 so as to be continuously wrapped around the outer periphery of the pipe 40 so as not to leave any gaps. The number of cooling materials 70-1 and 70-2 attached to the pipe 40 may be one, or may be three or more. The cooling amount Q ja is supplied to the pipe 40. The amount of cooling Q ja Since it has the effect of removing heat, the cooling amount Q ja The direction of the arrow in indicates the direction toward the outside of the pipe 40. When generating ice plug 51, the flow of water 50 in the pipe 40 is stopped and the cooling objects 70-1 and 70-2 are attached after the water 50 becomes stationary.

[0014] When the temperature of the air around the piping 40 (hereinafter referred to as the ambient temperature) is higher than the temperature of the piping 40, heat is supplied from the ambient air to the piping 40, i.e., a heat input state is established. Conversely, when the ambient temperature is lower than the temperature of the piping 40, heat is supplied from the piping 40 to the ambient air, i.e., a heat dissipation state is established. The amount of heat input from the ambient air and heat dissipation to the ambient air is hereinafter referred to as the ambient heat amount Q amb That is. Atmospheric heat Q amb is positive in the case of heat input and negative in the case of heat loss.

[0015] When a heat source 60 is disposed at the end of the pipe 40 or inside another pipe adjacent to the pipe 40, heat is supplied from the heat source 60 to the water 50 existing around the heat source 60, and the temperature of the water 50 rises. On the other hand, the amount of cooling Q supplied by the cooling objects 70-1 and 70-2 jaAs the water 50 is cooled by the above, convection occurs between the heat source 60 and the locations where the cooling objects 70-1 and 70-2 are attached, and the water 50 naturally circulates. This natural circulation of the water 50 supplies heat to the water 50 at the location where the ice plugs 51 are formed. The amount of heat input to the water 50 at the location where the ice plugs 51 are formed due to this natural circulation is hereinafter referred to as the natural circulation heat input Q in He said.

[0016] When the heat input state is reached and heat is supplied, the temperature of the pipe 40 rises, and part of the heat input is consumed by this increase in the temperature of the pipe 40. The amount of heat consumed by this increase in the temperature of the pipe 40 is hereinafter referred to as the sensible heat amount Q of the pipe 40. m When the heat input state is reached and heat is supplied, the temperature of the water 50 inside the pipe 40 rises, and part of the heat input is consumed by this increase in the temperature of the water 50. The heat consumed by this increase in the temperature of the water 50 is hereinafter referred to as the sensible heat quantity Q of the water 50. f Here, when the water 50 solidifies and the ice plug 51 is generated, the amount of heat released from the water 50 is called the solidification heat Q ice Then, the heat of solidification Q ice and the cooling amount Q ja and atmospheric heat Q amb and the natural circulation heat input Q in and the sensible heat quantity Q of pipe 40 m And the sensible heat of water 50 Q f In this case, the relationship expressed by the following equation (1) holds.

[0017]

number

[0018] To generate ice plugs, the heat of solidification Q ice must be a positive value, and for that to happen, the right-hand side of equation (1) must be negative. Therefore, the "cooling amount Q ja >Natural circulation heat input Q in + Atmospheric heat Q amb - Sensible heat quantity Q of pipe 40 m -Sensible heat Q of water 50 f " relationship is established.

[0019] The freeze plug generation possibility determination device 1 determines the amount of cooling Q based on the conditions set by the user. ja , atmospheric heat Q amb , natural circulation heat input Q in , sensible heat quantity Q of pipe 40 m , and the sensible heat of water 50 Q f Based on the calculations, the heat of solidification Q is calculated using the formula (1). ice The frozen plug generation possibility determination device 1 calculates the calculated solidification heat quantity Q ice Based on this, the time required for generating ice plugs 51 of a predetermined length is predicted, and based on whether the predicted time is within the time desired by the user, a determination is made as to whether ice plugs 51 can be generated.

[0020] (Example of the configuration of a device for determining whether or not a frozen plug can be generated) The freeze plug generation feasibility determination device 1 can be constructed using, for example, a computer such as a server, a personal computer, a microcomputer, or the like, and peripheral devices of the computer, and as a functional configuration consisting of a combination of hardware of the computer or the like and software such as a program executed by the computer, it has an input information acquisition unit 11, a memory unit 12, a heat quantity calculation unit 13, a predicted time calculation unit 14, a generation feasibility determination unit 15, and an output unit 16, as shown in Figure 1.

[0021] The input information acquisition unit 11 acquires input information, which is a condition determined by a user. The input information includes, for example, piping information, which is information about the piping 40, initial water temperature information indicating the temperature of the water 50 inside the piping 40 before cooling by the cooling objects 70-1 and 70-2, pipe water pressure information indicating the pressure of the water 50 inside the piping 40, ambient temperature information indicating the temperature of the air around the piping 40, heat source arrangement information indicating the arrangement state of the heat source 60 that supplies heat to the water 50, the number of cooling objects 70-1 and 70-2 used to generate ice plugs 51, and allowable time information indicating the time allowed for generating ice plugs 51, which is the time desired by the user.

[0022] The piping information includes information capable of identifying the outer diameter and inner diameter of the piping 40, information capable of identifying the overall length of the piping 40, and piping shape information indicating the type of shape of the piping 40. When the heat source arrangement information indicates that a heat source 60 is to be arranged, the piping information further includes the path length of the piping 40 from the position of the end of the piping 40 where the heat source 60 is arranged to the generation position of the ice plug 51.

[0023] As described above, the heat source 60 may actually be disposed at the end of the pipe 40, or may be disposed inside another pipe, etc., adjacent to the pipe 40. However, even if the heat source 60 is disposed inside another pipe, etc., adjacent to the pipe 40, the heat source 60 can be considered to be disposed at the end of the pipe 40 in terms of the phenomenon of natural circulation. Therefore, in the following, when it is stated that "the end of the pipe 40 where the heat source 60 is disposed," this description means both the case where the heat source 60 is actually disposed at the end of the pipe 40 and the case where the heat source 60 is disposed inside another pipe, etc., adjacent to the pipe 40.

[0024] The generation position of ice plug 51 is the center position of the part where ice plug 51 is generated, and the part where ice plug 51 is generated is the part of pipe 40 covered by cooling materials 70-1, 70-2 and the inside part where water 50 is present. However, since ice plug 51 is generated by utilizing the natural phenomenon of freezing, ice plug 51 is not actually generated with the same length on both sides of the generation position. Therefore, the generation position of ice plug 51 is a position that is appropriately determined by the user of freeze plug generation possibility determination device 1 in order to determine the positions to attach cooling materials 70-1, 70-2, and when ice plug 51 is actually generated, the center of generated ice plug 51 does not coincide with the generation position.

[0025] The information capable of identifying the outer diameter and the inner diameter of the pipe 40 is, for example, information indicating the specifications of the pipe 40. The pipe shape information indicating the type of the shape of the pipe 40 is, for example, information indicating which of the shapes of the pipe 40 indicated by the reference numerals 41, 42, and 43 shown in FIG.

[0026] Fig. 3(a) is a diagram showing a type of piping 40 consisting of a single horizontal pipe, and hereinafter, this type of piping 40 will be referred to as a single horizontal pipe 41. Fig. 3(b) is a diagram showing a type of piping 40 consisting of a single vertical pipe, and hereinafter, this type of piping 40 will be referred to as a single vertical pipe 42. Fig. 3(c) is a diagram showing a type of composite pipe 40 in which a horizontal pipe is joined to the upper end of a vertical pipe via an elbow portion, and hereinafter, this type of piping 40 will be referred to as a composite pipe 43. In the above and following descriptions, the term "piping 40" refers to any one of the single horizontal pipe 41, the single vertical pipe 42, and the composite pipe 43.

[0027] 3(a), when the position indicated by the reference numeral 80 is set as the generation position of the ice plug 51, the input information acquisition unit 11 acquires a piping path length L1 from the left end 81 to the generation position 80 and a piping path length L2 from the generation position 80 to the right end 82. Since the sum of the piping path length L1 and the piping path length L2 is the total length of the horizontal single pipe 41, in the case of the horizontal single pipe 41, the piping path length L1 and the piping path length L2 correspond to information capable of identifying the total length of the pipe 40 included in the above piping information.

[0028] 3(b), the input information acquisition unit 11 acquires a piping path length L1 from the lower end 81 to the generation position 80, and a piping path length L2 from the generation position 80 to the upper end 82. Since the sum of the piping path length L1 and the piping path length L2 is the total length of the vertical single pipe 42, in the case of the vertical single pipe 42, the piping path length L1 and the piping path length L2 correspond to information capable of identifying the total length of the piping 40 included in the above piping information.

[0029] 3(c), the position 80 where the ice plug 51 is generated is limited to any location in the horizontal pipe portion not including the elbow portion in the section between reference numerals 82 and 83. Here, in the compound pipe 43, the lower end of the vertical pipe portion in the section between reference numerals 81 and 83 is referred to as the vertical pipe end 81, the portion joining the vertical pipe portion and the horizontal pipe portion is referred to as the elbow portion 83, and the end of the horizontal pipe portion not joined to the elbow portion 83 is referred to as the horizontal pipe end 82.

[0030] In this case, the input information acquiring unit 11 acquires a piping path length L1 from the vertical pipe end 81 to the center position of the elbow portion 83, a piping path length L2 from the center position of the elbow portion 83 to the generation position 80, and a piping path length L3 from the generation position 80 to the horizontal pipe end 82. Since the total length of the piping path length L1, the piping path length L2, and the piping path length L3 is the total length of the compound pipe 43, in the case of the compound pipe 43, the piping path length L1, the piping path length L2, and the piping path length L3 correspond to information capable of identifying the total length of the pipe 40 included in the above piping information.

[0031] Note that the elbow portion 83 is actually an L-shaped pipe, and the elbow portion 83 itself has a piping path length. However, here, the piping path length of the elbow portion 83 is divided into two at the center position of the elbow portion 83, in other words, at the center position of the piping path length of the elbow portion 83, and one is included in the piping path length L1, and the other is included in the piping path length L2.

[0032] 3(a), in the case of a horizontal single pipe 41, the heat source arrangement information is information indicating whether or not the heat source 60 is arranged at the left end 81 and whether or not the heat source 60 is arranged at the right end 82. In the case of a vertical single pipe 42, the heat source arrangement information is information indicating whether or not the heat source 60 is arranged at the bottom end 81. In the case of a compound pipe 43, the heat source arrangement information is information indicating whether or not the heat source 60 is arranged at the vertical pipe end 81 and whether or not the heat source 60 is arranged at the horizontal pipe end 82.

[0033] In the case of the horizontal single pipe 41 shown in Fig. 3(a), among the piping path lengths L1 and L2, the piping path length where the heat source 60 is arranged at one end corresponds to the path length of the pipe 40 from the position of the end of the pipe 40 where the heat source 60 is arranged included in the above piping information to the generation position 80 of the ice plug 51. In the case of the vertical single pipe 42 shown in Fig. 3(b), when the heat source 60 is arranged at the lower end 81, the piping path length L1 corresponds to the path length of the pipe 40 from the position of the end of the pipe 40 where the heat source 60 is arranged included in the above piping information to the generation position 80 of the ice plug 51. In the case of the composite pipe 43 shown in Fig. 3(c), when the heat source 60 is arranged at the horizontal pipe end 82, the piping path length L3 corresponds to the path length of the pipe 40 from the position of the end of the pipe 40 where the heat source 60 is arranged included in the above piping information to the generation position 80 of the ice plug 51. Further, when the heat source 60 is arranged at the vertical pipe end 81 of the composite pipe 43, the sum of the piping path length L1 and the piping path length L2 corresponds to the path length of the pipe 40 from the position of the end of the pipe 40 where the heat source 60 is arranged included in the above piping information to the generation position 80 of the ice plug 51.

[0034] By the way, in the case of the horizontal single pipe 41 shown in Fig. 3(a), although the left end is denoted by reference numeral 81 and the right end is denoted by reference numeral 82 for explanation, the left and right in this case are irrelevant to the actual installation state. In the case of the horizontal single pipe 41, when the heat sources 60 are arranged at both ends, the piping path lengths L1 and L2 are determined such that the relationship L1 < L2 holds, and when the heat source 60 is arranged at one end, the side where the heat source 60 is arranged becomes L1. On the other hand, for the lower end 81 and the upper end 82 in the case of the vertical single pipe 42 shown in Fig. 3(b), and the vertical pipe end 81 and the horizontal pipe end 82 in the case of the composite pipe 43 shown in Fig. 3(c), the piping path lengths L1, L2, and L3 are determined to match the actual installation state.

[0035] 3(b), the reason why the presence or absence of the heat source 60 at the upper end 82 is not included in the heat source arrangement information is that the natural circulation of the water 50 caused by the heat source 60 placed at the upper end 82 occurs at a location above the upper end 82, resulting in thermal stratification and a state in which the water 50 above the upper end 82 and the water 50 below the upper end 82 do not mix. In other words, whether or not the heat source 60 is placed at the upper end 82, heat is not supplied by the natural circulation of the water 50 to the location where the ice plugs 51 are generated, so the presence or absence of the heat source 60 at the upper end 82 is not included in the heat source arrangement information.

[0036] The reason why the generation position 80 is not set in the vertical pipe portion not including the elbow portion in the section between the reference numerals 81 and 83 in the case of the compound pipe 43 in FIG. 3(c) is the same. That is, even if the heat source 60 is arranged at the horizontal pipe end 82 of the compound pipe 43, if the generation position 80 exists in the vertical pipe portion of the compound pipe 43, it is considered that the heat source 60 arranged at the horizontal pipe end 82 does not supply heat to the portion where the ice plug 51 is generated. In contrast, if the heat source 60 is arranged at the vertical pipe end 81 of the compound pipe 43, natural circulation similar to that in the case of the single vertical pipe 42 in FIG. 3(b) occurs in the vertical pipe portion of the compound pipe 43. Therefore, the case where the generation position 80 exists in the vertical pipe portion of the compound pipe 43 is included in the case where the ice plug 51 is generated in the single vertical pipe 42 with a total length of L1+L2+L3, that is, the case in FIG. 3(b).

[0037] As for the shape of the actual piping 40, in addition to that shown in Fig. 3, there are also shapes such as piping 44, 45, 46 shown in Fig. 4(a), (b), (c). In these shapes of piping 44, 45, 46, when a heat source 60 is disposed at any of the ends indicated by reference numerals 81, 82, 84 and ice plugs 51 are generated at the positions indicated by reference numerals 80-1, 80-2, 80-3, the phenomenon of natural circulation heat input occurring can be expressed by replacing it with any of the cases shown in Fig. 3(a), (b), (c). Therefore, the natural circulation heat input Q of all types of piping 40 can be calculated by the three types of piping, i.e., the horizontal single pipe 41, the vertical single pipe 42, and the compound pipe 43 shown in Fig. 3(a), (b), (c). in 3(a), (b), and (c) in this embodiment. However, in the case of the pipes 44, 45, and 46, depending on the position where the heat source 60 is disposed, it may be necessary to substitute the range of the pipe 40 from any of the ends 81, 82, and 84 to the elbow portion 83 via the location where the ice plug 51 is generated, and to consider the heat source 60 to be disposed at the elbow portion 83.

[0038] 2, the number of cooling materials 70-1, 70-2 used to generate ice plugs 51 acquired by input information acquisition unit 11 is "2." In the following description, when referring to any one of cooling materials 70-1, 70-2, it is referred to as cooling material 70.

[0039] The input information acquisition unit 11 refers to the piping specification table 31 stored in the storage unit 12, and identifies the outer diameter and inner diameter of the piping 40 from the information that can identify the outer diameter and inner diameter of the piping 40. The input information acquisition unit 11 calculates the total length of the piping 40 from the information that can identify the total length of the piping 40. The input information acquisition unit 11 replaces the information that can identify the outer diameter and inner diameter of the piping 40 in the acquired piping information with the identified outer diameter and inner diameter of the piping 40, and further includes the calculated total length of the piping 40 in the piping information, and outputs the piping information to the heat quantity calculation unit 13.

[0040] The input information acquisition unit 11 refers to the cooling material table 32 stored in the storage unit 12 and identifies the type of cooling material 70 corresponding to the identified outer diameter of the pipe 40, the cooling amount per piece, the length per piece, and the number of cylinders used per piece per hour. The input information acquisition unit 11 sets information including the number of cooling materials 70, the type of cooling material 70, the cooling amount per piece, the length per piece, and the number of cylinders used per piece per hour as cooling material information, and outputs the cooling material information to the heat amount calculation unit 13 and the predicted time calculation unit 14.

[0041] The input information acquisition unit 11 outputs the acquired initial water temperature information, pipe water pressure information, ambient temperature information, and heat source arrangement information to the heat quantity calculation unit 13. The input information acquisition unit 11 outputs the acquired permissible time information to the generation feasibility determination unit 15.

[0042] As shown in FIG. 5, the storage unit 12 stores in advance a piping specification table 31, a cooling material table 32, a fixed value table 33, and a physical property value table 34. The piping specification table 31 is a table that stores specification data of the JIS (Japan Industrial Standard) standard of the piping 40, for example, as shown in FIG. 6, and has a data format having items of "nominal diameter", "outer diameter", and "nominal thickness". The "nominal diameter" item further includes sub-items of "A" and "B", and the "nominal thickness" item includes sub-items of "Sch5", "Sch10", ..., "Sch160". Each item stores a numerical value of the JIS standard corresponding to each item. The unit of the numerical values ​​shown in the "outer diameter" item and the "nominal thickness" item is "mm".

[0043] 7, the cooling material table 32 is in a data format having items such as "piping outer diameter range," "type of cooling material," "cooling amount per unit," "length per unit," and "number of cylinders used per unit per hour." The "piping outer diameter range" item stores, for example, the outer diameter ranges of three pipes 40. The "type of cooling material" item stores "type 1," "type 2," and "type 3," which indicate the type of cooling material 70 corresponding to each of the three ranges of outer diameter of pipes 40.

[0044] The item of "cooling capacity per unit" stores the cooling capacity of each of the three types of coolants 70, which is the cooling capacity expressed in the unit of "W". In FIG. 6, an example of storing "α", "β", and "γ" as the cooling capacity is shown. However, "α", "β", and "γ" are actually numerical values. Generally, the larger the size of the coolant 70, the larger the value, so the relationship is α < β < γ. The item of "length per unit" stores the length of the coolant 70 in the central axis direction of the pipe 40 when one of each of the three types of coolants 70 is attached to the pipe 40, which is the value of the length expressed in the unit of "mm". In FIG. 6, an example of storing "A", "B", and "C" as the length of the coolant 70 is shown. However, "A", "B", and "C" are actually numerical values. Generally, the larger the size of the coolant 70, the larger the value, so the relationship is A < B < C.

[0045] The item of "number of cylinders used per unit time per unit" stores the number of cylinders used per hour in each of the three types of coolants 70 for one coolant 70. Here, the cylinder is a cylinder filled with carbon dioxide gas used to generate dry ice in the coolant 70. By attaching it to the coolant 70, the carbon dioxide gas in the cylinder is supplied to the coolant 70. In order to maintain the cooling capacity shown in the item of "cooling capacity per unit", when all the carbon dioxide gas in the cylinder attached to the coolant 70 is consumed, the cylinder attached to the coolant 70 is replaced with a cylinder filled with carbon dioxide gas. In FIG. 7, an example of storing "a", "b", and "c" as the number of cylinders used is shown. However, "a", "b", and "c" are actually numerical values. Generally, the larger the size of the coolant 70, the larger the value, so the relationship is a < b < c.

[0046] Returning to FIG. 5, the fixed value table 33 is such that the heat quantity calculation unit 13 calculates the natural circulation heat input quantity Q in , the ambient heat quantity Q amb , the sensible heat quantity Q of the pipe 40 m , and the sensible heat quantity Q of the water 50 fThe memory stores a predetermined fixed value that is used when performing a calculation to calculate

[0047] The physical property table 34 is a table in which the heat amount calculation unit 13 calculates the natural circulation heat input Q in , atmospheric heat Q amb , sensible heat quantity Q of pipe 40 m , and the sensible heat of water 50 Q f The physical property table 34 stores in advance each of the physical property values ​​specified by the water temperature and water pressure, which are used when performing a calculation to calculate water density. The physical property table 34 stores a table in a matrix data format in which, for example, for the physical property value of water density, each of the row items indicates a different number of temperature values ​​and each of the column items indicates a different number of pressure values, and each of the matrix elements is the water density value corresponding to the temperature value and pressure value that specify each element. The physical property table 34 stores tables in a similar data format for physical property values ​​other than the physical property value of water density.

[0048] 1, the heat amount calculation unit 13 includes a cooling amount calculation unit 21, a natural circulation heat input amount calculation unit 22, a temperature calculation unit 23, an atmosphere heat amount calculation unit 24, a piping sensible heat amount calculation unit 25, a water sensible heat amount calculation unit 26, and a solidification heat amount calculation unit 27. The cooling amount calculation unit 21 calculates the cooling amount Q based on the cooling material information output by the input information acquisition unit 11. ja Calculate.

[0049] The natural circulation heat input calculation unit 22 calculates the natural circulation heat input Q based on the piping shape information and the heat source arrangement information included in the piping information output by the input information acquisition unit 11. inThe natural circulation heat input calculation unit 22 selects a model formula for calculating the natural circulation heat input Q per unit time for the selected model formula, based on the piping information, the path length of the piping 40 where natural circulation occurs, which is derived from the path length of the piping 40 from the end position of the piping 40 where the heat source 60 included in the piping information is placed to the generation position 80 of the ice plug 51, the temperature of the water 50 which changes per unit time with the temperature indicated by the initial water temperature information as the initial value, the water pressure information in the piping, the cooling material information, the fixed values ​​stored in the fixed value table 33, and the physical property values ​​stored in the physical property table 34. in Calculate.

[0050] The temperature calculation unit 23 calculates the cooling amount Q ja and the natural circulation heat input Q in Based on the piping information and the physical properties stored in the physical property table 34, the temperature of the piping 40 and the temperature of the water 50 per unit time are calculated under the assumption that the temperature of the piping 40 and the temperature of the water 50 are the same temperature.

[0051] The atmospheric heat quantity calculation unit 24 calculates the outer surface area (hereinafter referred to as the outer surface area) of the portion of the pipe 40 that is in contact with the surrounding air, in other words, the outer surface area of ​​the portion of the pipe 40 that is not covered by the cooling material 70, based on the pipe information and the cooling material information. The atmospheric heat quantity calculation unit 24 calculates the atmospheric heat quantity Q per unit time based on the calculated outer surface area, the atmospheric temperature information, the temperature of the pipe 40 per unit time calculated by the temperature calculation unit 23, and the fixed value stored in the fixed value table 33. amb Calculate.

[0052] The pipe sensible heat amount calculation unit 25 calculates the sensible heat amount Q of the pipe 40 per unit time based on the volume of the material of the pipe 40 calculated from the pipe information, the amount of change in temperature of the pipe 40 per unit time that can be obtained from the temperature of the pipe 40 calculated per unit time by the temperature calculation unit 23, and the physical property values ​​stored in the physical property table 34. m Calculate.

[0053] The water sensible heat quantity calculation unit 26 calculates the sensible heat quantity Q of the water 50 per unit time based on the internal volume of the pipe 40 calculated from the pipe information, the amount of change in the water temperature per unit time that can be obtained from the temperature of the water 50 calculated per unit time by the temperature calculation unit 23, and the physical property values ​​stored in the physical property table 34. f Calculate.

[0054] The solidification heat calculation unit 27 calculates the cooling amount Q ja and the natural circulation heat input Q per unit time calculated by the natural circulation heat input calculation unit 22. in and the atmospheric heat quantity Q per unit time calculated by the atmospheric heat quantity calculation unit 24. amb and the sensible heat amount Q of the pipe 40 per unit time calculated by the pipe sensible heat amount calculation unit 25. m and the sensible heat quantity Q of the water 50 per unit time calculated by the water sensible heat quantity calculation unit 26. f Based on this, the amount of heat of solidification per unit time Q is calculated from equation (1). ice Calculate.

[0055] The predicted time calculation unit 14 calculates a predetermined length, which is a target length of the ice plug 51 to be generated in the pipe 40, based on the cooling material information output by the input information acquisition unit 11. As described above, the location where the ice plug 51 is generated is the part of the pipe 40 that is covered by all of the cooling material 70 attached to the pipe 40 and is an internal part where the water 50 exists. Therefore, the length of the part of the pipe 40 that is covered by all of the cooling material 70 attached to the pipe 40 in the central axis direction is set as the predetermined length of the ice plug 51 to be generated in the pipe 40. In the case of the example shown in FIG. 2, the length from the left end of the cooling material 70-1 to the right end of the cooling material 70-2 is the predetermined length of the ice plug 51 to be generated.

[0056] The predicted time calculation unit 14 is an arithmetic expression using the thickness of the ice forming the ice plug 51 as a variable, and is calculated based on the inner diameter of the pipe 40 included in the pipe information, the predetermined length to be calculated, the density of water, the solidification heat of water per unit mass, and the solidification heat Q per unit time calculated by the solidification heat calculation unit 27. iceThe predicted time is calculated based on an arithmetic expression that represents the reciprocal of the rate at which ice forming each ice plug 51 per unit time.

[0057] The generation possibility determination unit 15 determines whether or not ice plugs 51 can be generated, based on the predicted time calculated by the predicted time calculation unit 14 and the allowable time information output by the input information acquisition unit 11. The output unit 16 is an output device such as a liquid crystal display, and displays the determination result by the generation possibility determination unit 15, etc.

[0058] (Example of operation of the device for determining whether or not a freeze plug can be generated) An example of the operation of the freeze plug generation possibility determination device 1 will be described with reference to the flowcharts shown in Figures 8 to 11. Note that in the flowcharts shown in Figures 8, 9, and 10, the symbols "A" or "B" in a circle indicate that the processing is continuous at the location of the same symbol. That is, after the processing of S10 in Figure 8, the processing of S21 in Figure 9 is performed, and if the determination of "No" is made in the determination processing of S32 in Figure 9, the processing of S41 in Figure 10 is performed.

[0059] When processing is started in the freeze plug generation possibility determination device 1, the input information acquisition unit 11 reads out "stainless steel" indicating the piping material to be processed that is predetermined in the freeze plug generation possibility determination device 1, from the fixed value table 33 in the storage unit 12. The input information acquisition unit 11 displays on the output unit 16 a screen that displays the read-out "stainless steel" as the piping material to be processed, and that displays input fields for each of the piping specifications, piping shape, initial water temperature, water pressure inside the piping, ambient temperature, and allowable time (S1).

[0060] A user of the freeze plug generation possibility determination device 1 refers to the screen displayed on the output unit 16 and confirms that the material of the pipe 40 that is the target of processing by the freeze plug generation possibility determination device 1 is "stainless steel," while performing input operations in each of the input fields displayed on the screen. The input field for the pipe specifications is, for example, an input field in the form of a pull-down menu for selecting one of a plurality of pipe specifications. The input field for the pipe shape is also, for example, an input field in the form of a pull-down menu for selecting one of three types: a horizontal single pipe 41, a vertical single pipe 42, and a composite pipe 43. The input fields for the initial water temperature, the water pressure inside the pipe, the ambient temperature, and the allowable time are input fields into which the corresponding numerical values ​​are written.

[0061] When a temperature is entered in the input field, the unit is "°C", when a pressure is entered, the unit is "MPaA", and when a time is entered, the unit is "hours". Input operations are performed via input devices such as a mouse or keyboard connected to the freeze plug generation possibility determination device 1.

[0062] The input information acquisition unit 11 acquires the piping specification and piping shape selected in the input fields as piping specification information and piping shape information, respectively. The input information acquisition unit 11 sets information including the acquired piping specification information and piping shape information as piping information. The input information acquisition unit 11 acquires the initial water temperature, water pressure in the pipe, ambient temperature, and permissible time written in the input fields as initial water temperature information, water pressure in the pipe information, ambient temperature information, and permissible time information, respectively (S2).

[0063] The input information acquisition unit 11 identifies the outer diameter and inner diameter of the pipe 40 based on the acquired pipe specification information and the pipe specification table 31. For example, when the pipe specification information is "6B Sch160", the input information acquisition unit 11 detects a record in which "6" is stored in the sub-item "B" of the "nominal diameter" item in the pipe specification table 31 shown in FIG. 6 based on the pipe specification information "6B". The input information acquisition unit 11 detects "165.2" stored in the "outer diameter" item of the detected record, and sets 165.2 [mm] as the outer diameter D of the pipe 40. o Let us assume that.

[0064] The input information acquisition unit 11 further detects "18.2" stored in the sub-item "Sch160" of the "nominal thickness" item of the detected record based on "Sch160" of the piping specification information, and determines 18.2 [mm] as the thickness of the piping 40. The input information acquisition unit 11 subtracts the thickness "18.2" x 2 from the outer diameter "165.2" to determine 128.8 [mm] as the inner diameter D of the piping 40. i The input information acquiring unit 11 replaces the piping specification information included in the piping information with an outer diameter of 165.22 [mm] and an inner diameter of 128.8 [mm] (S3).

[0065] The input information acquisition unit 11 selects the type of cooling material 70 based on the outer diameter 165.2 [mm] of the pipe 40 and the cooling material table 32. In the cooling material table 32 shown in FIG. 7, 165.2 [mm] corresponds to "100 mm or more and less than 500 mm" in the second line of the item "range of pipe outer diameter". Therefore, the input information acquisition unit 11 detects "Type 2" stored in the item "Type of cooling material", "β" [W] stored in the item "amount of cooling per unit", "B" [mm] stored in the item "length per unit", and "b" [bottles / hour] stored in the item "number of cylinders used per unit per hour" of the record in the second line of the cooling material table 32. The input information acquisition unit 11 displays on the output unit 16 a screen that displays the detected “Type 2” as the type of cooling material 70, and “β” [W] as the amount of cooling per piece, and also displays an input field for the number of cooling materials 70 (S4).

[0066] The user refers to the screen displayed on the output unit 16, and confirms that the type of cooling material 70 to be used is "type 2" and that the cooling amount per "type 2" cooling material 70 is "β" [W], and performs an input operation to write the number of cooling materials 70 in the input field displayed on the screen. Here, it is assumed that the user writes "2" as the number of cooling materials 70. The input information acquisition unit 11 acquires "2", which is the number of cooling materials 70 written in the input field. The input information acquisition unit 11 generates cooling material information including the acquired number of cooling materials 70 "2", the type of cooling material 70 detected "type 2", the cooling amount per one "β" [W], the length per one "B" [mm], and the number of cylinders used per one hour "b" [bottles / hour] (S5). Hereinafter, the two cooling materials 70 indicated by this cooling material information are also referred to as cooling materials 70-1 and 70-2, as in FIG. 2.

[0067] The input information acquisition unit 11 displays on the output unit 16 a screen showing an image of any one of FIG. 3(a), FIG. 3(b), and FIG. 3(c) corresponding to the acquired piping shape information (S6).

[0068] When the image of the horizontal single pipe 41 in Figure 3(a) is displayed on the output unit 16, the image displays, for example, two input fields in which the length of each section of the piping route lengths L1, L2 can be entered as a numerical value in the unit [mm], and two input fields near each of the points indicated by symbols 81 and 82 in which "with heat source" or "without heat source" can be selected from a pull-down menu.

[0069] When the image of the vertical pipe 42 in Figure 3(b) is displayed on the output unit 16, the image displays, for example, two input fields in which the length of each section of the piping route lengths L1, L2 can be entered as a numerical value in the unit [mm], and one input field near each of the locations indicated by the symbol 81 in which "with heat source" or "without heat source" can be selected from a pull-down menu.

[0070] When the image of the composite pipe 43 in Figure 3 (c) is displayed on the output unit 16, the image displays, for example, three input fields in which the length of each section of the piping route lengths L1, L2, L3 can be entered as a numerical value in the unit [mm], and two input fields near each of the points indicated by symbols 81 and 82 in which "with heat source" or "without heat source" can be selected from a pull-down menu.

[0071] Each of the input fields in which "with heat source" and "without heat source" can be selected from a pull-down menu is linked with information identifying the type of end (e.g., left end 81, right end 82, bottom end 81, vertical pipe end 81, horizontal pipe end 82) existing in the vicinity of each of the input fields. When a user performs an input operation to select either "with heat source" or "without heat source", the input information acquisition unit 11 associates the selected information of either "with heat source" or "without heat source" with information identifying the type of end linked to the input field in which the information was selected, and acquires it as heat source arrangement information (S7).

[0072] Each of the input fields in which the length of each section of the piping path lengths L1, L2, and L3 can be written as a numerical value is linked to information that specifies which section of the piping path lengths L1, L2, and L3 the corresponding section of the piping path length is. When a user performs an input operation in which a numerical value is written in the input field for each section of the piping 40, the input information acquisition unit 11 acquires the numerical value written in the input field and information that specifies the section of the piping path length that is linked to the input field in which the numerical value is written, as information that can specify the total length of the piping 40, and includes the acquired information in the piping information (S8).

[0073] The input information acquisition unit 11 calculates the total piping length L by adding up the numerical values ​​for each section of the piping path length included in the acquired information capable of identifying the total length of the piping 40, and includes the calculated total piping length L in the piping information (S9). The input information acquisition unit 11 outputs the piping information, initial water temperature information, water pressure information inside the piping, ambient temperature information, heat source arrangement information, and cooling material information to the heat quantity calculation unit 13. The input information acquisition unit 11 outputs the cooling material information to the predicted time calculation unit 14. The input information acquisition unit 11 outputs the allowable time information to the generation feasibility determination unit 15 (S10).

[0074] (Cooling amount Q ja (Calculation process) 9, in the heat quantity calculation unit 13, the cooling amount calculation unit 21 takes in the cooling material information output by the input information acquisition unit 11. The cooling amount calculation unit 21 multiplies the cooling amount "β" [W] included in the taken-in cooling material information by the number of cooling materials 70, "2". The cooling amount calculation unit 21 calculates "2β" [W] obtained by the multiplication as the cooling amount Q ja The cooling amount calculation unit 21 calculates the cooling amount Q ja to the temperature calculation unit 23 and the coagulation heat calculation unit 27 (S21).

[0075] (Calculation process of pipe and water temperature per unit time) The temperature calculation unit 23 receives the piping information, the initial water temperature information, and the water pressure information in the pipes output by the input information acquisition unit 11 in the process of S10, and records the received piping information, the initial water temperature information, and the water pressure information in the pipes in an internal storage area. ja The amount of cooling taken in is Q ja is recorded in the internal memory area.

[0076] The temperature calculation unit 23 calculates the temperature of the pipe 40 and the temperature of the water 50 per unit time using the following equation (2), which is established under the assumption that the temperature of the pipe 40 and the temperature of the water 50 are the same temperature.

[0077]

number

[0078] In equation (2), T ave (t) is the temperature of the water 50 at time t, and is the temperature of the pipe 40. Δt and dt are unit times, which are predetermined very short times. ave (0), i.e., time t is "0" T ave (t) is the temperature indicated by the initial water temperature information.

[0079] In the first term of the denominator of the second term on the right-hand side of equation (2), ρ w is the density of water at 50 [kg / m 3 ] and C p,w is the specific heat of water at 50 [J / (kg.K)], and ρ w , C p,w is a physical property value stored in the physical property table 34. i 2 In "L", D i is the inner diameter of the pipe 40 included in the pipe information, and L is the total length of the pipe 40 included in the pipe information. i 2 L" is the internal volume [m 3 Therefore, the unit of the value calculated by the first term in the denominator of the second term on the right side of formula (2) is "J / K", and this value indicates the amount of heat required to raise the temperature of water 50 in pipe 40 by 1 [K], that is, 1 [℃].

[0080] In the second term of the denominator of the second term on the right-hand side of equation (2), ρ m is the density [kg / m 3 ] and C p,m is the specific heat [J / (kg.K)] of the stainless steel that is the material of the pipe 40, and ρ m , C p,m is a physical property value stored in the physical property table 34. o 2 -D i 2 )L" D ois the outer diameter of the pipe 40 included in the pipe information. o 2 -D i 2 )L” is the volume [m 3 Therefore, the unit of the value calculated by the second term in the denominator of the second term on the right side of formula (2) is "J / K", and this value indicates the amount of heat required to raise the temperature of pipe 40 by 1 [K], that is, 1 [°C].

[0081] The numerator of the second term on the right side of equation (2) is the amount of cooling Q ja Natural circulation heat input Q at time t in This is a value obtained by subtracting the above, and indicates the water 50 in the pipe 40 and the amount of cooling [W] supplied to the pipe 40 at time t. Note that the amount of cooling Q supplied from the cooling objects 70-1 and 70-2 attached to the pipe 40 is ja is a constant value that does not change with time, and in the process of S21, the cooling amount Q ja The natural circulation heat input Q at time t in is the natural circulation heat input Q most recently calculated by the natural circulation heat input calculation unit 22. in However, when the formula (2) is calculated for the first time, that is, when the time t is "0", there is no change in the temperature of the water 50. Therefore, when the formula (2) is calculated for the first time, the natural circulation heat input Q in will become "0".

[0082] "Q ja -Q in The unit of " is "W", or "J / s (second)". The unit of the denominator of the second term on the right side of equation (2) is "J / K" as described above. Therefore, in the second term on the right side of equation (2), the unit before multiplication by "dt" is "K / s", and after multiplication by "dt", the second term on the right side of equation (2) indicates the amount of change in the temperature of pipe 40 and the temperature of water 50 over unit time dt (= Δt).

[0083] When calculating the formula (2) for the first time, the temperature calculation unit 23 calculates ρ w , C p,w , ρ m , C p,m The temperature calculation unit 23 detects T ave (0) is the temperature indicated by the initial water temperature information stored in the internal memory area, and the natural circulation heat input Q in As described above, the temperature calculation unit 23 sets the detected ρ w , C p,w , ρ m , C p,m and the cooling amount Q stored in the internal memory area. ja and the inner diameter D included in the piping information stored in the internal memory area. i , outer diameter D o Using the total length L of the pipe 40, T ave Calculate (0 + Δt) [℃].

[0084] When calculating the formula (2) for the second or subsequent times, the temperature calculation unit 23 calculates the previously calculated T ave (t+Δt) to T ave (t), T ave Based on (t) and the pressure indicated by the water pressure information in the pipe, ρ w , C p,w , ρ m , C p,m The temperature calculation unit 23 detects the detected ρ w , C p,w , ρ m , C p,m and the cooling amount Q stored in the internal memory area. ja and the natural circulation heat input Q at time t most recently calculated by the natural circulation heat input calculation unit 22. in and the inner diameter D included in the piping information stored in the internal memory area. i , outer diameter D o Using the total length L of the pipe 40, T ave Calculate (t+Δt) [℃].

[0085] The temperature calculation unit 23 continues to calculate T ave The temperature calculation unit 23 repeatedly calculates (t+Δt). ave Time t+Δt is associated with (t+Δt) and output to natural circulation heat input calculation unit 22, atmosphere heat calculation unit 24, piping sensible heat calculation unit 25, and water sensible heat calculation unit 26 (S22). As a result, the processes of S24, S25, S26, and S27 shown below are started in parallel by atmosphere heat calculation unit 24, piping sensible heat calculation unit 25, water sensible heat calculation unit 26, and natural circulation heat input calculation unit 22.

[0086] (Atmospheric heat quantity Q amb (Calculation process) The atmospheric heat quantity calculation unit 24 calculates T ave (t+Δt) to T metal The ambient heat quantity calculation unit 24 takes in the piping information, ambient temperature information, and cooling material information output by the input information acquisition unit 11 in the process of S10, and records the taken in piping information, ambient temperature information, and cooling material information in an internal storage area.

[0087] The atmospheric heat quantity calculation unit 24 calculates the outer diameter D o Using the total length L of the piping 40, "πD o ×L” to calculate the outer surface area of ​​the pipe 40. The atmospheric heat quantity calculation unit 24 calculates “πD o ×B×2" to calculate the outer surface area of ​​the pipe 40 of the portion covered by the cooling objects 70-1 and 70-2. The atmospheric heat quantity calculation unit 24 subtracts the calculated outer surface area of ​​the pipe 40 of the portion covered by the cooling objects 70-1 and 70-2 from the calculated outer surface area of ​​the pipe 40 to obtain the outer surface area S of the pipe 40 in contact with the surrounding air. heat Calculate.

[0088] The atmospheric heat quantity calculation unit 24 calculates the pipe outer surface heat transfer coefficient ho [W / m 2 .K] and the temperature T indicated by the ambient temperature information stored in the internal memory area. amb [℃] and the captured T metal [℃] and the calculated external surface area S heat [m 2 ], the atmospheric heat quantity Q at time t + Δt is calculated using the following equation (3). amb The atmospheric heat quantity calculation unit 24 calculates the calculated atmospheric heat quantity Q amb The time t+Δt is associated with this and output to the coagulation heat calculation unit 27 (S24).

[0089]

number

[0090] (Pipe sensible heat Q m (Calculation process) The pipe sensible heat calculation unit 25 calculates T ave (t+Δt) is taken in, and time t+Δt and T ave (t+Δt) and records it in an internal storage area. Piping sensible heat calculation unit 25 takes in the piping information, initial water temperature information, and piping water pressure information output by input information acquisition unit 11 in the process of S10, and records the taken in piping information, initial water temperature information, and piping water pressure information in an internal storage area.

[0091] The piping sensible heat amount calculation unit 25 calculates the sensible heat amount Q of the piping 40 at time t+Δt based on the following equation (4). m Calculate [W].

[0092]

number

[0093] The numerator on the right side of formula (4) is "T ave (t)-T aveThe formula "(t+Δt)" is a formula for calculating the amount of change in temperature of the pipe 40 during a unit time. The pipe sensible heat calculation unit 25 calculates the amount of change in temperature of the pipe 40 during a unit time from the internal storage area. ave (t+Δt) and the previously recorded T ave (t). The pipe sensible heat calculation unit 25 reads out T ave (t) to T ave (t+Δt) is subtracted to calculate the amount of change in the temperature of the pipe 40 during the unit time at time t+Δt. Note that when calculating the formula (4) for the first time, the time t representing the previous time is set to "0", and T ave (0) is not stored in the internal storage area. Therefore, the pipe sensible heat calculation unit 25 regards the temperature indicated by the initial water temperature information stored in the internal storage area as the initial temperature of the pipe 40, and sets the temperature indicated by the initial water temperature information as T ave (0), and the amount of change in temperature of the pipe 40 during a unit time of time Δt is calculated.

[0094] The piping sensible heat calculation unit 25 calculates the numerator "T ave (t)-T ave For equations other than "(t+Δt)", the temperature calculation unit 23 calculates the second term of the denominator of the second term on the right side of equation (2) in the process of S22 using the contents stored in the internal storage area. The sensible heat amount calculation unit 25 calculates the sensible heat amount Q of the pipe 40 at time t+Δt by dividing the calculation result of the numerator of equation (4) by unit time dt. m The sensible heat quantity calculation unit 25 calculates the sensible heat quantity Q of the piping 40. m The time t+Δt is associated with this and output to the coagulation heat calculation unit 27 (S25).

[0095] (Water sensible heat Q f (Calculation process) The water sensible heat calculation unit 26 calculates T ave (t+Δt) is taken in, and time t+Δt and T ave(t+Δt) and records it in an internal storage area. Water sensible heat calculation unit 26 takes in the piping information, initial water temperature information, and in-pipe water pressure information output by input information acquisition unit 11 in the process of S10, and records the taken in piping information, initial water temperature information, and in-pipe water pressure information in an internal storage area.

[0096] The water sensible heat calculation unit 26 calculates the sensible heat Q of the water 50 at time t+Δt based on the following equation (5). f Calculate [W].

[0097]

number

[0098] The numerator on the right side of formula (5) is "T ave (t)-T ave The formula "(t+Δt)" is a formula for calculating the amount of change in temperature of water 50 during a unit time. The water sensible heat calculation unit 26 calculates the amount of change in temperature of water 50 during a unit time from the internal storage area. ave (t+Δt) and the previously recorded T ave (t). The water sensible heat calculation unit 26 reads out T ave (t) to T ave (t+Δt) is subtracted to calculate the amount of change in temperature of the water 50 during the unit time at time t+Δt. Note that when calculating the formula (5) for the first time, the time t representing the previous time is set to "0", and T ave (0) is not stored in the internal storage area. Therefore, the water sensible heat calculation unit 26 sets the temperature indicated by the initial water temperature information stored in the internal storage area as T ave (0), and calculate the amount of change in temperature of the water 50 over a unit time of time Δt.

[0099] The water sensible heat calculation unit 26 calculates the numerator "T ave (t)-T aveFor equations other than "(t+Δt)", the temperature calculation unit 23 uses the contents stored in the internal storage area to calculate the sensible heat quantity Q of the water 50 at time t+Δt by the same procedure as that used to calculate the first term of the denominator of the second term on the right side of equation (2) in the process of S22. The sensible heat quantity Q of the water 50 at time t+Δt is calculated by dividing the calculation result of the numerator of equation (5) by unit time dt. f The water sensible heat calculation unit 26 calculates the calculated sensible heat Q f The time t+Δt is associated with this and output to the coagulation heat calculation unit 27 (S26).

[0100] (Natural circulation heat input Q in (Calculation process) The natural circulation heat input calculation unit 22 calculates the temperature T associated with the time t+Δt output by the temperature calculation unit 23. ave The natural circulation heat input calculation unit 22 takes in the piping information, the initial water temperature information, the water pressure information in the piping, the heat source arrangement information, and the cooling material information output by the input information acquisition unit 11 in the process of S10, and records the taken in piping information, the initial water temperature information, the water pressure information in the piping, the heat source arrangement information, and the cooling material information in an internal storage area.

[0101] The natural circulation heat input calculation unit 22 determines whether the heat source arrangement information stored in the internal storage area indicates that the heat source 60 is arranged (S27). When the natural circulation heat input calculation unit 22 determines that the heat source arrangement information does not indicate that the heat source 60 is arranged (S27, No), the natural circulation heat input calculation unit 22 calculates the natural circulation heat input Q in is set to "0", and the natural circulation heat input Q in The imported T ave The time t+Δt associated with (t+Δt) is associated with the temperature calculation unit 23 and the coagulation heat calculation unit 27 (S28).

[0102] On the other hand, if the natural circulation heat input calculation unit 22 determines that the heat source placement information indicates that the heat source 60 is placed (S27, Yes), it performs processing of the subroutine for the natural circulation heat input calculation process shown in FIG. 11 (S29).

[0103] Hereinafter, the process performed by the natural circulation heat input calculation unit 22 when a heat source 60 is installed will be described with reference to Fig. 11. The natural circulation heat input calculation unit 22 determines whether or not the piping shape information included in the piping information stored in the internal storage area indicates a horizontal single pipe 41 (Sa1).

[0104] <Calculation process of natural circulation heat input in case of horizontal single pipe> It is assumed that the natural circulation heat input calculation unit 22 determines that the piping shape information indicates the horizontal single pipe 41 (Sa1, Yes). In this case, the natural circulation heat input calculation unit 22 selects the following formula (6) and formula (7) as model formulas corresponding to the horizontal single pipe 41.

[0105]

number

[0106]

number

[0107] Here, the phenomenon of heat input caused by natural circulation in the case of the horizontal single tube 41 will be described. Fig. 12 is a cross-sectional view of the horizontal single tube 41 between the left end 81 and the generation position 80 when the horizontal single tube 41 is cut in a vertical plane including the central axis 100 of the horizontal single tube 41. Fig. 13 is a cross-sectional view of the horizontal single tube 41 when cut along the line XX shown in Fig. 12. In Fig. 12, a heat source 60 is disposed at the left end 81 of the horizontal single tube 41, and cooling objects 70-1 and 70-2 are attached near the generation position 80 of the horizontal single tube 41.

[0108] In this case, water 50 is heated by heat source 60 at left end 81 and cooled by cooling devices 70-1, 70-2 attached near generation position 80, so that water 50 naturally circulates in the direction of the arrow shown in Fig. 12. This natural circulation causes water 50 in horizontal single tube 41 to separate into two layers: high temperature layer 55 located above horizontal single tube 41 and low temperature layer 57 located below, as shown in Fig. 13. In high temperature layer 55, water 50 flows from left end 81 toward generation position 80, and in low temperature layer 57, water 50 flows from generation position 80 toward left end 81.

[0109] In this embodiment, the cross-sectional area of ​​the high temperature layer 55 and the cross-sectional area of ​​the low temperature layer 57 are the same area, and as shown in Figs. 12 and 13, the length between the center height of the high temperature layer 55 indicated by reference numeral 101 and the center height of the low temperature layer 57 indicated by reference numeral 102 is, for example, equal to the inner diameter D i Therefore, the center height of the high temperature layer 55 indicated by the reference numeral 101 is (1 / 4)D higher than the height of the central axis 100. i The center height of the low temperature layer 57, indicated by reference numeral 102, is (1 / 4)D higher than the height of the central axis 100. i It will be at a lower height.

[0110] In equation (6), G on the right side is the flow rate per hour of the water 50 circulating by natural circulation (hereinafter referred to as the natural circulation flow rate), and is a value expressed in units of [kg / s] calculated by equation (7). hot is the specific enthalpy of water in the high temperature layer 55 [J / kg], and h cold is the specific enthalpy [J / kg] of the water in the low temperature layer 57. The specific enthalpy of water is a physical property value stored in the physical property table 34.

[0111] Formula (7) expresses the case where the cross-sectional area of ​​the high temperature layer 55 and the cross-sectional area of ​​the low temperature layer 57 are the same, and the length between the center height of the high temperature layer 55 indicated by reference numeral 101 and the center height of the low temperature layer 57 indicated by reference numeral 102 is equal to the inner diameter D of the horizontal single pipe 41. i12 occurs when the head difference between high temperature layer 55 and low temperature layer 57 shown on the left side is balanced with the friction pressure loss in horizontal single pipe 41 shown on the right side, assuming that the head difference between high temperature layer 55 and low temperature layer 57 is 0.5 times the head difference between high temperature layer 55 and low temperature layer 57. Here, the head difference between high temperature layer 55 and low temperature layer 57 is the difference in head pressure between high temperature layer 55 and low temperature layer 57, or in other words, the difference in potential energy between high temperature layer 55 and low temperature layer 57.

[0112] In equation (7), ρ hot is the fluid density [kg / m 3 ], and ρ cold is the fluid density [kg / m 3 ] and fluid density [kg / m 3 ] is a physical property value stored in the physical property table 34. g is the gravitational acceleration [m / s 2 ], which is a fixed value stored in the fixed value table 33. h is the cross-sectional area of ​​the high-temperature layer 55 [m 2 ]. λ e is the equivalent friction coefficient. Equivalent friction coefficient λ e is a coefficient used to adjust the head difference between the high temperature layer 55 and the low temperature layer 57 calculated from the left side of equation (7) and the friction pressure loss in the horizontal single pipe 41 calculated from the right side of the equation so as to balance each other.

[0113] L hot is the piping path length in the portion where natural circulation occurs, specifically, the piping path length from the end of the horizontal single pipe 41 where the heat source 60 is arranged to the end of the cooling material 70 on the side where the heat source 60 is arranged.

[0114] For example, the position of the end of the cooling material 70 on the side where the heat source 60 is arranged and the procedure for identifying that position will be described with reference to the piping 40 shown in FIG. 2. In the case of FIG. 2, the heat source 60 is arranged at the left end of the piping 40, and the end position of the cooling material 70 on the side where the heat source 60 is arranged is the left end position of the cooling material 70-1. The cooling materials 70-1 and 70-2 are continuously attached to the piping 40 without any gaps so that the lengths on both sides are the same, with the ice plug 51 generation position 80 as the center. Therefore, when two cooling materials 70-1 to 70-2 are attached, one cooling material 70 is attached on each side, so that the position where the cooling materials 70-1 and 70-2 come into contact coincides with the ice plug 51 generation position 80. Note that in the actual installation state, it is not required that the lengths on both sides are completely the same, and the L calculated by the natural circulation heat input calculation unit 22 is used as the center. hot In the calculation of (a), it is merely assumed that the lengths on both sides are the same, and in the actual installation state, it is sufficient if the lengths on both sides are approximately the same.

[0115] The length of the piping 40 from the left end of the piping 40 where the heat source 60 is disposed to the generation position 80 of the ice plug 51 is the piping path length L1 in the case of the horizontal single pipe 41. Therefore, in the case of the horizontal single pipe 41, when the heat source 60 is disposed at the left end 81, L hot is the length obtained by subtracting half the length in the central axis direction of the portion of the horizontal single pipe 41 covered by the cooling materials 70-1, 70-2 attached to the horizontal single pipe 41 (hereinafter, this length is referred to as the cooling material length) from the piping path length L1 included in the piping information. The cooling material length is a value that can be calculated by multiplying the number of cooling materials 70 included in the cooling material information by the length of the cooling materials 70.

[0116] When the piping shape information indicates the horizontal single pipe 41 and the heat source arrangement information indicates a state in which the heat source 60 is arranged, the input operation described above is performed so that the heat source 60 is always arranged at the left end 81 in Fig. 3(a). Therefore, the natural circulation heat input calculation unit 22 performs the following process after selecting formula (6) and formula (7).

[0117] The natural circulation heat input calculation unit 22 calculates half the length of the cooling material by performing the calculation "B x 2 x 1 / 2" using the length "B" of the cooling material 70 included in the cooling material information stored in the internal storage area and the number of cooling materials 70 "2". The natural circulation heat input calculation unit 22 subtracts half the length of the cooling material from the piping path length L1 to obtain L corresponding to the piping path length L1. hot Calculate.

[0118] The natural circulation heat input calculation unit 22 regards the temperature indicated by the initial water temperature information stored in the internal memory area as the temperature of the water 50 in the high temperature layer 55, i.e., the temperature of the water 50 heated by the heat source 60, and calculates the fluid density ρ hot Detect.

[0119] The natural circulation heat input calculation unit 22 calculates the input T ave By substituting (t+Δt) into the following equation (8), the temperature T of the water 50 inside the pipe 40 in the part covered by the cooling object 70 is obtained. cold In addition, in formula (8), T hot is the temperature of the water 50 heated by the heat source 60. Here, the temperature indicated by the initial water temperature information stored in the internal memory area is regarded as the temperature of the water 50 heated by the heat source 60, and T hot Therefore, T ave (0)=T hot At time t=0, T cold =T hot =T ave (0). Furthermore, equation (8) is T cold and T hot The average value of T ave (t+Δt). In this sense, equation (8) is based on the assumption that the temperature distribution from the end of pipe 40 where heat source 60 is located to the inside of pipe 40 where the part is covered by cooling medium 70 is linear.

[0120]

number

[0121] The natural circulation heat input calculation unit 22 calculates the T cold is regarded as the temperature of the water 50 in the low-temperature layer 57, and the fluid density ρ cold Detect.

[0122] As described above, the cross-sectional area of ​​the high temperature layer 55 and the cross-sectional area of ​​the low temperature layer 57 are the same. Therefore, the natural circulation heat input calculation unit 22 uses the inner diameter D i Using (D i / 2) 2 By calculating ×π / 2, the flow path cross-sectional area A of the high temperature layer 55 is h Calculate.

[0123] The natural circulation heat input calculation unit 22 regards the temperature indicated by the initial water temperature information stored in the internal storage area as the temperature of the water 50 heated by the heat source 60, and calculates the natural circulation heat input amount by comparing the temperature with the total length L and the inner diameter D of the horizontal single pipe 41 included in the piping information stored in the internal storage area. i Using the above, the equivalent friction coefficient λ e Calculate.

[0124] The natural circulation heat input calculation unit 22 calculates the fluid density ρ hot , and the fluid density ρ of the low-temperature layer 57 cold the gravitational acceleration g stored in the fixed value table 33, and the inner diameter D included in the piping information stored in the internal storage area. i and L corresponding to the calculated piping path length L1 hot , the flow path cross-sectional area A of the high temperature layer 55 h , and the equivalent friction coefficient λ e and are substituted into equation (7) to calculate the natural circulation flow rate G.

[0125] The natural circulation heat input calculation unit 22 regards the temperature indicated by the initial water temperature information stored in the internal storage area as the temperature of the water 50 in the high temperature layer 55, and calculates the specific enthalpy h of the water 50 in the high temperature layer 55 from the physical property table 34 based on the temperature and the pressure indicated by the water pressure information in the piping stored in the internal storage area. hot The natural circulation heat input calculation unit 22 detects T calculated by the formula (8). cold is regarded as the temperature of the water 50 in the low-temperature layer 57, and the specific enthalpy h of the water 50 in the low-temperature layer 57 is calculated from the physical property table 34 based on the temperature and the pressure indicated by the water pressure information in the pipe stored in the internal storage area. cold Detect.

[0126] The natural circulation heat input calculation unit 22 calculates the natural circulation flow rate G calculated by the formula (7) and the detected specific enthalpy h hot , and the specific enthalpy h of water 50 in the low-temperature layer 57 cold Substituting this into equation (6), the natural circulation heat input Q in Calculate the natural circulation heat input Q in is the natural circulation heat input Q from the heat source 60 located at the left end 81 of the horizontal single pipe 41 shown in FIG. in become.

[0127] The natural circulation heat input calculation unit 22 determines whether or not the heat source arrangement information stored in the internal storage area indicates that the heat source 60 is arranged at the right end 82 of the horizontal single pipe 41 shown in Fig. 3(a) (Sa3). When the natural circulation heat input calculation unit 22 determines that the heat source arrangement information does not indicate that the heat source 60 is arranged at the right end 82 of the horizontal single pipe 41 (Sa3, No), the process proceeds to process Sa11.

[0128] On the other hand, the natural circulation heat input calculation unit 22 determines that the heat source arrangement information indicates that the heat source 60 is arranged at the right end 82 of the horizontal single-pipe 41 (Sa3, Yes). In this case, the natural circulation heat input calculation unit 22 selects the formulas (6) and (7), which are model formulas corresponding to the horizontal single-pipe 41, and then performs the same process as the process of Sa2 after selecting the formulas (6) and (7), except that the piping path length L1 is replaced with the piping path length L2, to calculate the natural circulation heat input Q in Calculate the natural circulation heat input Q in is the natural circulation heat input Q from the heat source 60 located at the right end 82 of the horizontal single pipe 41 shown in FIG. in The natural circulation heat input calculation unit 22 then advances the process to step Sa11.

[0129] <Calculation process of natural circulation heat input in case of single vertical pipe> In the process of Sa1, the natural circulation heat input calculation unit 22 determines that the piping shape information does not indicate a horizontal single pipe 41 (Sa1, No). In this case, the natural circulation heat input calculation unit 22 next determines whether or not the piping shape information indicates a vertical single pipe 42 (Sa5). When the natural circulation heat input calculation unit 22 determines that the piping shape information indicates a vertical single pipe 42 (Sa5, Yes), it selects the following formula (9) and formula (10) as model formulas corresponding to the vertical single pipe 42.

[0130]

number

[0131]

number

[0132] Here, a description will be given of the heating section and the cooling section, which are two sections formed in the water 50 in the single vertical pipe 42 by natural circulation when the heat source 60 is disposed at the lower end 81 of the single vertical pipe 42. Fig. 14 is a cross-sectional view of the single vertical pipe 42 when the single vertical pipe 42 is cut along a vertical plane including the central axis of the single vertical pipe 42. Fig. 14 shows an example in which two cooling objects 70-1, 70-2 are attached to the single vertical pipe 42. The single vertical pipe 42 has a piping path length L1 in the downward direction and a piping path length L2 in the upward direction, with the center position of the cooling objects 70-1, 70-2, i.e., the generation position 80, as the boundary.

[0133] The water 50 heated by the heat source 60 arranged at the lower end 81 rises in the single vertical pipe 42, while being cooled by the objects to be cooled 70-1, 70-2, and falls in the single vertical pipe 42. As such natural circulation occurs in the water 50 in the single vertical pipe 42, the water 50 is separated into two parts, the heating section 53, which is a section close to the heat source 60, and the cooling section 52, which is a section close to the objects to be cooled 70-1, 70-2. In this embodiment, it is assumed that the heating section 53 and the cooling section 52 have the same volume. Under this assumption, the heating section 202-2, which is the length of the heating section 53, and the cooling section 202-1, which is the length of the cooling section 52, are defined as follows.

[0134] The length of the vertical single pipe 42 in the central axis direction of the portion covered by the cooling object 70-1 indicated by reference numeral 200 is half the length of the cooling object that can be calculated from the cooling object information. The length from the lower end 81 of the vertical single pipe 42 indicated by reference numeral 201 to the lower end of the cooling object 70-1 can be obtained by subtracting the length indicated by reference numeral 200 from the piping path length L1. The length indicated by reference numeral 201 is defined as the piping path length of the portion where natural circulation occurs in the vertical single pipe 42. When the piping path length of the portion where natural circulation occurs is divided in half, the upper half is defined as the cooling portion 202-1, which is the length of the cooling section 52, and the lower half is defined as the heating portion 202-2, which is the length of the heating section 53.

[0135] In equation (9), h r is the heat transfer coefficient [W / m2 .K], which is calculated by equation (10). T hot,ave is the average temperature of the heating part 53 [°C]. cold,ave is the average temperature [°C] of the cooling section 52. Here, the temperature indicated by the initial water temperature information is regarded as the average temperature of the heating section 53, and T hot,ave Also, the temperature calculation unit 23 applies the T ave T calculated from (t+Δt) using equation (8) cold is regarded as the average temperature of the cooling section 52, T cold,ave Applies to.

[0136] S hot is the surface area of ​​the heating section 53, in other words, the area [m 2 ].

[0137] In formula (10), λ is the thermal conductivity at the average temperature [W / mK], and is a physical property value stored in the physical property table 34. r is the so-called Nusselt number, which represents the ratio of heat conduction to heat transfer in a convecting fluid.

[0138] After selecting formula (9) and formula (10), the natural circulation heat input calculation unit 22 performs the following process. The natural circulation heat input calculation unit 22 calculates half the length of the cooled material from the cooled material information by the same procedure as that described in the process of Sa2. The natural circulation heat input calculation unit 22 subtracts half the calculated length of the cooled material from the piping path length L1 included in the piping information stored in the internal storage area to calculate the length indicated by reference numeral 201 in Fig. 14, and multiplies the calculated length by 1 / 2 to calculate the cooling length 202-1 and the heating length 202-2.

[0139] The natural circulation heat input calculation unit 22 calculates the input T aveBased on (t+Δt) and the pressure indicated by the piping water pressure information, a plurality of physical property values ​​such as the Prandtl number of the average temperature are detected from the physical property table 34, and the physical property values ​​for calculating the Nusselt number are detected. ave Based on (t+Δt), the piping information stored in the internal storage area, the temperature indicated by the initial water temperature information, the gravitational acceleration g stored in the fixed value table 33, and the detected physical property values ​​for calculating the Nusselt number, the Nusselt number Nu r Calculate.

[0140] The natural circulation heat input calculation unit 22 calculates the input T ave Based on (t+Δt) and the pressure indicated by the water pressure information in the pipe, the thermal conductivity λ of the average temperature is detected from the physical property table 34. The natural circulation heat input calculation unit 22 calculates the calculated Nusselt number Nu r The thermal conductivity λ of the detected average temperature and the inner diameter D included in the piping information stored in the internal memory area i Substituting this into equation (10), we obtain the heat transfer coefficient h r Calculate.

[0141] The natural circulation heat input calculation unit 22 calculates the natural circulation heat input amount by calculating the inner diameter D i Using the calculated heating section length 202-2, "πD i × (length of heating section 202-2)" to obtain the surface area S of the heating section 53. hot Calculate.

[0142] The natural circulation heat input calculation unit 22 calculates the heat transfer coefficient h r and the calculated area S hot Applying this to equation (9), the temperature indicated by the initial water temperature information stored in the internal memory area and the T ave T calculated from (t+Δt) using equation (8) cold and T in Eq. (9), respectively. hot,ave And, T cold,ave Substituting and the natural circulation heat input Q inThe natural circulation heat input calculation unit 22 then advances the process to step Sa11.

[0143] <Calculation process of natural circulation heat input in case of composite pipe> In the process of Sa5, the natural circulation heat input calculation unit 22 determines that the piping shape information does not indicate a vertical single pipe 42 (Sa5, No). In this case, the remaining type is the compound pipe 43, so the natural circulation heat input calculation unit 22 determines whether or not the heat source arrangement information indicates that the heat source 60 is arranged at the vertical pipe end 81 of the compound pipe 43 shown in Fig. 3(c) (Sa7). When the natural circulation heat input calculation unit 22 determines that the heat source arrangement information does not indicate that the heat source 60 is arranged at the vertical pipe end 81 of the compound pipe 43 (Sa7, No), the process proceeds to Sa10.

[0144] When the natural circulation heat input calculation unit 22 determines that the heat source placement information indicates that the heat source 60 is placed at the vertical pipe end 81 of the composite pipe 43 (Sa7, Yes), it selects equation (6) and the following equation (11) as model equations corresponding to the composite pipe 43.

[0145]

number

[0146] Here, a description will be given of the phenomenon of heat input caused by natural circulation when a heat source 60 is disposed at the vertical pipe end 81 of the composite pipe 43. Fig. 15 is a cross-sectional view of the composite pipe 43 between the vertical pipe end 81 and the production position 80 when the composite pipe 43 is cut along a vertical plane including the central axis 100 of the horizontal pipe portion 43h of the composite pipe 43. In Fig. 15, the composite pipe 43 is shown divided into three portions: the hatched elbow portion 43e, the horizontal pipe portion 43h joined to the elbow portion 43e, and the vertical pipe portion 43v.

[0147] By arranging the heat source 60 at the vertical pipe end 81 of the composite pipe 43, natural circulation in the direction of the arrow indicated by the symbol 110 (hereinafter referred to as natural circulation 110) occurs in the water 50 in the vertical pipe section 43v, and natural circulation in the direction of the arrow indicated by the symbol 111 (hereinafter referred to as natural circulation 111) occurs in the water 50 in the horizontal pipe section 43h and the elbow section section 43e.

[0148] In this natural circulation 111, water 50 cooled by cooling objects 70-1 and 70-2 attached near the generation position 80 flows through horizontal pipe portion 43h from the generation position 80 toward elbow portion 43e, and then enters toward elbow portion 43e. Water 50 that has entered elbow portion 43e is heated by water 50 in natural circulation 110 and rises, returns to horizontal pipe portion 43h, and flows toward generation position 80. In this case, in a cross section taken along line YY in Figure 15, water 50 is in the same state as that shown in Figure 13, that is, separated into two layers, high temperature layer 55 and low temperature layer 57.

[0149] 12, in the case of the composite pipe 43, the vertical length of the high temperature layer 55 and the vertical length of the low temperature layer 57 are not uniform in the elbow portion 43e, and the vertical length of the low temperature layer 57 is longer. The depth to which the water 50 penetrates into the elbow portion 43e by natural circulation 111 is the height indicated by reference symbol 103, and the vertical length between the height indicated by reference symbol 105 of the bottom end of the horizontal pipe portion 43h and the height indicated by reference symbol 103 is defined as the "natural circulation penetration depth ΔL."

[0150] The center height of the high temperature layer 55 indicated by the reference symbol 101 is (1 / 4)D higher than the height of the central axis 100, as in the case of the horizontal single pipe 41 shown in FIG. i In contrast, the center height of the low temperature layer 57 in the composite pipe 43 is the height indicated by the reference symbol 104, which is (1 / 2)ΔL lower than the height indicated by the reference symbol 102 which is the center height of the low temperature layer 57 in the case of the horizontal single pipe 41 shown in FIG.

[0151] Therefore, in the case of the compound pipe 43, when the heat source 60 is disposed at the vertical pipe end 81, the head difference between the high temperature layer 55 and the low temperature layer 57 increases by "(1 / 2)ΔL" compared to the case of the horizontal single pipe 41 shown in FIG. 12. Considering this increase in the head difference of "(1 / 2)ΔL", "(1 / 2)ΔL" on the left side of the formula (7) used in the case of the horizontal single pipe 41 is i " + "(1 / 2)ΔL" is added to the equation shown on the left side of equation (11).

[0152] In the case of the horizontal pipe 41, "L" on the right side of the formula (7) hot " is the length of the piping path where natural circulation occurs, and by using this piping path length, the left and right sides of equation (7) are balanced. Therefore, in order to balance with the left side of equation (11), "L hot " must be set to the piping path length where natural circulation 111 occurs.

[0153] The piping path length of the portion where natural circulation 111 occurs is the piping path length from the vertical pipe end 81 to the generation position 80, i.e., the total length of the piping path length L1 and the piping path length L2, minus the piping path length L1 and half the length of the coolant, and then adding the natural circulation penetration depth ΔL. Note that on the right side of equation (11), the length obtained by subtracting the piping path length L1 and half the length of the coolant from the total length of the piping path length L1 and the piping path length L2, i.e., the length obtained by subtracting half the length of the coolant from the piping path length L2, is defined as "L hot " and this "L hot The formula for adding the natural circulation penetration depth ΔL to the above is shown.

[0154] As a result, the formula (11) becomes a model formula expressing the occurrence of the natural circulation 111 shown in FIG. 15. In this embodiment, the natural circulation penetration depth ΔL is i is a value calculated by multiplying a predetermined coefficient, and this coefficient is stored in the fixed value table 33 in advance.

[0155] After selecting the formula (6) and the formula (11), the natural circulation heat input calculation unit 22 performs the following process. The natural circulation heat input calculation unit 22 selects the inner diameter D i is multiplied by a coefficient for calculating the natural circulation penetration depth stored in the fixed value table 33 to calculate the natural circulation penetration depth ΔL.

[0156] The natural circulation heat input calculation unit 22 calculates half the length of the cooling material from the cooling material information by the same procedure as that described in the process of Sa2. The natural circulation heat input calculation unit 22 subtracts the calculated half of the cooling material length from the piping path length L2 included in the piping information to obtain L corresponding to the piping path length L2. hot The natural circulation heat input calculation unit 22 calculates the flow path cross-sectional area A of the high temperature layer by the same procedure as the processing of Sa2. h and the equivalent friction coefficient λ e The natural circulation heat input calculation unit 22 calculates the fluid density ρ hot and the fluid density of the low-temperature layer, ρ cold and detects.

[0157] The natural circulation heat input calculation unit 22 calculates the fluid density ρ hot , and the fluid density of the low-temperature layer ρ cold the gravitational acceleration g stored in the fixed value table 33, and the inner diameter D included in the piping information stored in the internal storage area. i and L corresponding to the calculated piping path length L2 hot , natural circulation penetration depth ΔL, high temperature layer flow cross-sectional area A h , and the equivalent friction coefficient λ e and are substituted into equation (11) to calculate the natural circulation flow rate G.

[0158] The natural circulation heat input calculation unit 22 calculates the specific enthalpy h of the water 50 in the high temperature layer by the same procedure as the processing of Sa2. hot and the specific enthalpy h of water 50 in the low-temperature layer 57 cold The natural circulation heat input calculation unit 22 detects the natural circulation flow rate G calculated by the formula (11) and the detected specific enthalpy h hot, and the specific enthalpy of water 50 in the low-temperature layer h cold Substituting this into equation (6), the natural circulation heat input Q in Calculate the natural circulation heat input Q in is the natural circulation heat input Q from the heat source 60 arranged at the vertical pipe end 81 of the composite pipe 43 shown in FIG. in become.

[0159] The natural circulation heat input calculation unit 22 determines whether or not the heat source arrangement information indicates that the heat source 60 is arranged at the horizontal pipe end 82 of the compound pipe 43 shown in Fig. 3(c) (Sa9). When the natural circulation heat input calculation unit 22 determines that the heat source arrangement information does not indicate that the heat source 60 is arranged at the vertical pipe end 81 of the compound pipe 43 (Sa9, No), the process proceeds to the process of Sa11.

[0160] On the other hand, the natural circulation heat input calculation unit 22 determines that the heat source arrangement information indicates that the heat source 60 is arranged at the vertical pipe end 81 of the compound pipe 43 (Sa9, Yes). In this case, the natural circulation heat input calculation unit 22 selects the formulas (6) and (7), which are model formulas corresponding to the horizontal single pipe 41, and then performs the same process as the process of Sa2 after selecting the formulas (6) and (7), except that the piping path length L1 is replaced with the piping path length L3, to calculate the natural circulation heat input Q in Calculate the natural circulation heat input Q in is the natural circulation heat input Q from the heat source 60 arranged at the horizontal tube end 82 of the composite tube 43 shown in FIG. in The natural circulation heat input calculation unit 22 then advances the process to step Sa11.

[0161] When performing the process of Sa11 following the process of Sa2, Sa6, and Sa8, and the process of Sa10 which is performed without passing through the process of Sa8, the natural circulation heat input calculation unit 22 calculates the natural circulation heat input Q in The imported T ave The time t+Δt associated with (t+Δt) is associated with the temperature calculation unit 23 and the solidification heat calculation unit 27.

[0162] When performing the process of Sa2, the process of Sa4, and then the process of Sa11, the natural circulation heat input calculation unit 22 calculates the natural circulation heat input Q in When performing the process of Sa10 after the process of Sa8, and then the process of Sa11, the natural circulation heat input calculation unit 22 calculates the natural circulation heat input Q calculated in each of the processes of Sa8 and Sa10. in When the natural circulation heat input calculation unit 22 calculates the total value, the natural circulation heat input Q in The natural circulation heat input Q in The imported T ave The time t+Δt associated with (t+Δt) is associated with the temperature calculation unit 23 and the solidification heat calculation unit 27 (Sa11). This ends the subroutine of the natural circulation heat input calculation process.

[0163] In the process of S22 in FIG. 9, when the temperature calculation unit 23 performs the calculation by the formula (2) for the first time, the natural circulation heat input Q in It has been explained that the specific enthalpy h of the water 50 in the high temperature layer 55 can be set to "0". To elaborate on this, in the case of the horizontal single pipe 41 and the compound pipe 43, when the time t is "0", the temperature of the water 50 in the high temperature layer 55 and the temperature of the water 50 in the low temperature layer 57 are the same. Therefore, the specific enthalpy h hot and the specific enthalpy h of water 50 in the low-temperature layer 57 cold Therefore, from equation (6), the natural circulation heat input Q in In the case of the vertical single pipe 42, the average temperature T hot,ave and the average temperature T of the water 50 in the cooling section 52 cold,ave Therefore, from equation (9), the natural circulation heat input Q in will be "0".

[0164] Returning to FIG. 9, the solidification heat calculation unit 27 calculates the cooling amount Q output by the cooling amount calculation unit 21 in the process of S21. jaThe solidification heat quantity calculation unit 27 calculates the atmospheric heat quantity Q associated with the time t+Δt output by the atmospheric heat quantity calculation unit 24. amb and the piping sensible heat amount Q associated with the time t+Δt output by the piping sensible heat amount calculation unit 25 m and the water sensible heat quantity Q associated with the time t+Δt output by the water sensible heat quantity calculation unit 26 f and the natural circulation heat input Q associated with the time t+Δt output by the natural circulation heat input calculation unit 22 in and incorporate.

[0165] The solidification heat calculation unit 27 calculates the cooling amount Q stored in the internal storage area in the formula (1). ja and the atmospheric heat quantity Q associated with the time t+Δt taken in amb , sensible heat quantity of pipe Q m , water sensible heat Q f , and natural circulation heat input Q in Substituting and, the heat of solidification at time t+Δt, Q ice The coagulation heat quantity calculation unit 27 calculates the calculated coagulation heat quantity Q at the time t+Δt. ice to the predicted time calculation unit 14 (S30).

[0166] In this embodiment, it is assumed that ice that forms ice plug 51 with a uniform thickness is generated from the inner surface of pipe 40 at the location where ice plug 51 is generated toward the central axis of pipe 40. Fig. 16 is a diagram showing a state in which ice plug 51 with a thickness of s [m] is generated at a certain time under this assumption. At this point, ice plug 51 has a hollow cylindrical shape, and the area around central axis 100 is not frozen and water 50 is present therein. As time passes, s increases and the area becomes larger than the inner diameter D i When the length of the ice plug 51 reaches half of the original length, the ice plug 51 becomes cylindrical and is completed.

[0167] The solidification heat calculation unit 27 calculates the solidification heat Q at time t+Δt using the following formula (12). ice Calculate the increased ice thickness ds.

[0168]

number

[0169] In equation (12), ρ ice is the density of ice [kg / m 3 ]. fus is the heat of solidification of water per unit mass [J / kg]. Note that unit mass is 1 kg. The density of ice, ρ ice and the heat of solidification of water per unit mass h fus is a physical property value that changes depending on temperature and pressure, but is not a value that changes significantly. Therefore, in this embodiment, for example, when the temperature is 0 [°C] and the pressure is atmospheric pressure, i.e., 0.1 [MPaA], the density ρ ice and the heat of solidification of water per unit mass h fus are stored as fixed values ​​in the fixed value table 33.

[0170] L ice is a predetermined length that is a target length of ice plug 51 formed in pipe 40, and is a length that coincides with the above-mentioned cooled object length. s is a variable indicating the thickness of the ice, and its initial value is "0".

[0171] Therefore, "2π × L" in equation (12) ice ×(D i The formula "(s)" is a formula for calculating the inner surface area of ​​ice plug 51 when the thickness of ice plug 51 becomes s, in other words, the area of ​​the part where ice plug 51 and water 50 are in contact. ice is the amount of heat Q supplied during Δt ice This is expressed as ρ ice And, h fus The increase in ice volume during Δt [m 3 The increase in ice volume during Δt [m 3 ] to "2π × L ice ×(D i / 2-s) gives the increase in ice thickness ds during Δt.

[0172] The solidification heat calculation unit 27 performs a calculation of "B x 2" using the length "B" of the cooling material 70 included in the cooling material information stored in the internal storage area and the number of cooling materials 70 "2" to obtain the predetermined length L of the ice plug 51. ice Calculate.

[0173] When performing the initial calculation of the solidification heat amount calculation unit 27, s = 0 is set, and the calculated L ice and the ice density ρ stored in the fixed value table 33. ice , and the heat of solidification of ice per unit mass h fus and the inner diameter D included in the piping information stored in the internal memory area. i and the solidification heat Q at time t+Δt calculated in the process of S30 ice and are applied to the formula (12) to calculate ds. The solidification heat calculation unit 27 records the calculated value of ds as the thickness s of the ice in an internal storage area.

[0174] When performing the second or subsequent calculation of formula (12), the solidification heat calculation unit 27 calculates L ice and the ice density ρ stored in the fixed value table 33. ice , and the heat of solidification of ice per unit mass h fus and the inner diameter D included in the piping information stored in the internal memory area. i and the ice thickness s and the heat of solidification Q at time t+Δt calculated in the process of S30. ice and are applied to formula (12) to calculate ds. The solidification heat calculation unit 27 adds the calculated ds to the ice thickness s stored in the internal memory area, and records the result as the new ice thickness s in the internal memory area (S31).

[0175] The solidification heat calculation unit 27 calculates the thickness s of the ice calculated in the process of S31 as follows: i The solidification heat calculation unit 27 determines whether the thickness s of the ice is equal to or greater than D iWhen it is determined that the thickness s of the ice is not equal to or greater than D / 2 (S32, No), the temperature calculation unit 23 outputs a stop instruction signal to the temperature calculation unit 23. When the temperature calculation unit 23 receives the stop instruction signal from the solidification heat calculation unit 27, it stops the process of S22. On the other hand, the solidification heat calculation unit 27 determines that the thickness s of the ice is equal to or greater than D i If it is determined that the time is not equal to or greater than / 2 (S32, Yes), a prediction start instruction signal is output to the predicted time calculation unit .

[0176] 10, in the process of S30 which is repeatedly performed, the predicted time calculation unit 14 calculates the coagulation heat quantity Q associated with the time t+Δt by the coagulation heat quantity calculation unit 27. ice Each time the output is made, the amount of solidification heat Q associated with time t+Δt is ice and records it in an internal storage area. Furthermore, the predicted time calculation unit 14 takes in the cooling object information output by the input information acquisition unit 11 in the process of S10 and records it in an internal storage area.

[0177] The predicted time calculation unit 14 calculates the amount of solidification heat Q per unit time stored in an internal storage area. ice Using the above, the predicted time t p Calculate.

[0178]

number

[0179] "2π×L" in equation (13) ice ×(D i The formula "2π×L / 2-s" is a formula for calculating the area of ​​the part where ice plug 51 and water 50 are in contact, similar to formula (12). Here, as shown in FIG. 16, it is assumed that ice with a thickness of ds [m] is further generated during unit time dt (=Δ). In this case, "2π×L ice ×(D i The formula "ρ / 2-s)ds" is an equation for calculating an approximation of the volume of ice generated per unit time dt (= Δt). ice is the density of ice, so "ρ ice ×2π×L ice ×(D iThe formula "mass of ice produced per unit time dt" is used to calculate an approximation of the mass of ice produced per unit time dt, and the calculated value is expressed in kg.

[0180] h in Eq. (13) fus / Q ice Q with the numerator and denominator swapped ice / h fus The unit is [kg / s], which indicates the mass of ice generated per second. However, the heat of solidification Q ice is a value that changes every unit time Δt. Therefore, "ρ ice ×h fus ×2π×L ice ×(D i / 2-s) / Q ice The unit of the calculated value of the formula is [s / m], and it is a formula for calculating the inverse of the ice generation rate in each unit time dt. Therefore, formula (13) as a whole calculates the inverse of the ice generation rate in each unit time dt based on the thickness ds of ice generated during the unit time dt, from s=0 to D i / 2. This integral is s=0~D i The time required for ice to form to a thickness of ds at all s between 1 / 2 is calculated, and this time is the predicted time t p become.

[0181] Therefore, when the predicted time calculation unit 14 receives a prediction start instruction signal from the solidification heat calculation unit 27, it performs the following process. The predicted time calculation unit 14 performs a calculation of "B x 2" using the length "B" of the cooled object 70 included in the cooled object information stored in the internal storage area and the number of cooled objects 70 "2" to obtain the predetermined length L of the ice plug 51. ice Calculate.

[0182] The predicted time calculation unit 14 calculates the L ice and the ice density ρ stored in the fixed value table 33. ice , and the heat of solidification of ice per unit mass h fusand the inner diameter D included in the piping information stored in the internal memory area. i and the amount of heat of solidification Q per unit time Δt stored in the internal memory area. ice Applying this to equation (13) to predict time t p The predicted time calculation unit 14 calculates the calculated predicted time t p to the generation possibility determination unit 15 (S41).

[0183] The generation possibility determination unit 15 acquires the permissible time information output by the input information acquisition unit 11 in the process of S10 and records it in an internal storage area. p When the predicted time t p It is determined whether the time is equal to or less than the permissible time indicated by the permissible time information stored in the internal storage area (S42).

[0184] The generation possibility determination unit 15 predicts the predicted time t p is not within the allowable time (S42, No), information indicating "unable to generate" and the predicted time t p is displayed on the output unit 16 (S43), and the process ends.

[0185] On the other hand, the generation possibility determination unit 15 predicts the predicted time t p is equal to or shorter than the allowable time (S42, Ye), information indicating "generation possible" and the predicted time t p The above is displayed on the output unit 16, and a signal instructing the predicted time calculation unit 14 to calculate the number of cylinders consumed (S44).

[0186] When the predicted time calculation unit 14 receives a signal instructing calculation of the number of cylinders consumed from the generation possibility determination unit 15, it calculates the number of cooling materials 70 "2" included in the cooling material information stored in the internal storage area, the number of cylinders used per unit per hour "b", and the predicted time t p For example, the number of cylinders consumed is calculated based on the predicted time t pIf b is "5 hours", the number of cylinders to be consumed is calculated by performing the calculation "5×b×2". The predicted time calculation unit 14 displays the calculated predicted number of cylinders on the output unit 16 (S45), and ends the process.

[0187] The input information acquisition unit 11 outputs the outer diameter D of the pipe 40 included in the pipe information and the cooling material information to the heat amount calculation unit 13 and the predicted time calculation unit 14. o , inner diameter D i The unit of length of the cooling object 70 is [mm]. In contrast, in the calculations of formulas (2) to (13) performed by the heat quantity calculation unit 13 and the predicted time calculation unit 14, the unit of length is [m]. Therefore, the heat quantity calculation unit 13 and the predicted time calculation unit 14 convert the units before substituting them into formulas (2) to (13).

[0188] (Action and effect) In the freeze plug generation possibility determination device 1 according to the embodiment of the present disclosure, the conditions are set to include piping information on the piping 40 in which ice plugs 51 are generated by being cooled by the cooling material 70, the initial water temperature, the water pressure in the piping, the ambient temperature, heat source arrangement information showing the arrangement state of the heat source 60, cooling material information on the cooling material 70, and an allowable time, whereby the heat quantity calculation unit 13 calculates the solidification heat quantity Q per unit time supplied to the water 50 in the piping 40. ice The predicted time calculation unit 14 calculates the coagulation heat amount Q per unit time calculated by the heat amount calculation unit 13. ice Based on this, a predicted time t p The generation possibility determination unit 15 calculates the predicted time t p and determines whether ice plugs 51 can be formed based on the allowable time. Therefore, with frozen plug formation possibility determination device 1, it is possible to determine whether ice plugs 51 can be formed within a desired time based on the determined conditions, without actually forming ice plugs 51.

[0189] Various shapes are conceivable for the shape of the piping 40, but when all conceivable patterns of arrangement of the heat source 60 in each of the various shapes are applied, it is possible to classify the natural circulation phenomenon occurring in the internal water 50 and cover all phenomena into three types: a horizontal single pipe 41, a vertical single pipe 42, and a composite pipe 43. For this reason, the freeze plug generation possibility determination device 1 is configured to select and determine one of the three types of piping shapes, the horizontal single pipe 41, the vertical single pipe 42, and the composite pipe 43, in the piping information, thereby making it possible to simplify the configuration of the input information acquisition unit 11 and the natural circulation heat input calculation unit 22.

[0190] (Another configuration example of the embodiment) Although the embodiment of the present disclosure has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present disclosure are also included.

[0191] In the above embodiment, three types of piping shapes, namely, a horizontal single pipe 41, a vertical single pipe 42, and a composite pipe 43, can be selected, which makes it possible to simplify the configurations of the input information acquisition unit 11 and the natural circulation heat input calculation unit 22. However, from the viewpoint of ease of use, it is preferable to make other shapes such as those shown in FIG. 4 selectable, since this makes it easier to check against the shape of the piping 40 that is actually installed. Therefore, shapes other than the horizontal single pipe 41, the vertical single pipe 42, and the composite pipe 43 may be selectable. Even if other shapes are selectable in this way, the natural circulation heat input Q due to the other shapes may be calculated. in The calculation process is for the natural circulation heat input Q in the case of horizontal single pipe 41, vertical single pipe 42, and composite pipe 43. in Therefore, in the configuration of the natural circulation heat input calculation unit 22, the number of branching processes for classifying the shape of the pipe 40 increases as the shape of the pipe 40 increases, but the natural circulation heat input Q in The configuration for calculating the above will be of approximately the same scale as in this embodiment.

[0192] In the above embodiment, the initial water temperature entered by the user in the process of S2 in Figure 8 is the temperature of the water 50 inside the pipe 40 before cooling by the cooling material 70, but if the water temperature inside the pipe 40 is unknown, and if a sufficient amount of time has passed since the operation of a plant or the like in which the pipe 40 is installed is stopped and it is assumed that the surface temperature of the pipe 40 and the temperature of the water 50 inside the pipe 40 are approximately the same, the surface temperature of the pipe 40 may be measured and used as the initial water temperature.

[0193] Furthermore, when the pipe 40 is either the horizontal single pipe 41 or the compound pipe 43, and heat sources 60 are arranged at both ends and the temperatures of the two heat sources 60 are different, the temperature of the water 50 near one heat source 60 will be different from the temperature of the water 50 near the other heat source 60. In this case, the user may set the initial water temperature to, for example, the average temperature of the two water 50, or the temperature of the water 50 inside the pipe 40 at a position about the same piping path length from the two heat sources 60, or the temperature of the water 50 with the higher temperature. By setting the temperature of the water 50 with the higher temperature as the initial water temperature, it becomes possible to more reliably predict the time when ice plugs 51 will be generated.

[0194] Furthermore, in the case where the two heat sources 60 have different temperatures, the following configuration may be used. One of the two heat sources 60 is designated as a first heat source, and the other is designated as a second heat source. In this case, the input information acquisition unit 11 acquires information indicating the temperature of the water 50 near the first heat source heated by the first heat source as first heat source heating water temperature information, and acquires the temperature of the water 50 near the second heat source heated by the second heat source as second heat source heating water temperature information. The first heat source heating water temperature information is linked to the first heat source, and the second heat source heating water temperature information is linked to the second heat source. The natural circulation heat input calculation unit 22 calculates the natural circulation heat input Q due to natural circulation caused by the first heat source. in When calculating the amount of natural circulation heat input Q due to natural circulation caused by the second heat source, the temperature indicated by the first heat source heating water temperature information linked to the first heat source is used as the temperature of the water 50 in the high temperature layer 55 or the average temperature of the heating unit 53. inWhen calculating, the temperature indicated by the second heat source heating water temperature information linked to the second heat source is used as the temperature of the water 50 in the high temperature layer 55 or the average temperature of the heating unit 53. In this case, the input information acquisition unit 11 may acquire, as the initial water temperature, the average value of the temperature indicated by the first heat source heating water temperature information and the temperature indicated by the second heat source heating water temperature information, or the temperature of the water 50 inside the pipe 40 at a position at a piping path length approximately the same from each of the first heat source and the second heat source may be measured, and the input information acquisition unit 11 may acquire the measured temperature as the initial water temperature information.

[0195] In the above embodiment, the user writes the water pressure in the pipe in the process of S2 in Fig. 8. In response to this, in preparation for the case where the water pressure in the pipe cannot be measured and is unknown, for example, the atmospheric pressure value "0.1 MPaA" may be stored as a fixed value in the fixed value table 33. In this way, even if the water pressure in the pipe is unknown and the user does not write the water pressure in the pipe in the input field in the process of S2, and the input information acquisition unit 11 cannot acquire the water pressure in the pipe, the process requiring the water pressure in the pipe can refer to the fixed value of the water pressure in the pipe from the fixed value table 33 and perform the process.

[0196] In the above embodiment, the cooling materials 70 are attached to the pipes 40 continuously without any gaps, and ice plugs 51 are generated throughout the entire inside of the pipes 40 covered by the cooling materials 70, and the predetermined length of the ice plugs 51 is calculated by multiplying the number of cooling materials 70 included in the cooling material information by the length of the cooling materials 70. However, in reality, ice plugs 51 may not be generated throughout the entire inside of the pipes 40 covered by the cooling materials 70, and the predetermined length may be shorter than the length obtained by multiplying the number of cooling materials 70 included in the cooling material information by the length of the cooling materials 70. In such a case, it is possible to more accurately estimate the predicted time t pIn order to calculate the above, for example, in the process of S2, an input field of a predetermined length may be displayed, and the user may enter the predetermined length that he or she predicts, which is then acquired by the input information acquiring unit 11, and the predicted time calculating unit 14 may use the predetermined length acquired by the input information acquiring unit 11 in the calculation of equation (13).

[0197] In the above embodiment, in the case of the horizontal single pipe 41, L shown in formula (7) hot is defined as the "piping path length of the portion where natural circulation occurs", specifically, the path length of the horizontal single pipe 41 from the end (left end 81 or right end 82) of the horizontal single pipe 41 where the heat source 60 is arranged to the end of the cooling material 70 on the side where the heat source 60 is arranged. In the case of the vertical single pipe 42, the "piping path length of the portion where natural circulation occurs" is divided into two parts having a length in half, one of which closer to the heat source 60 is the heating section 53 and the other is the cooling section 52. Specifically, as shown in FIG. 14, the two parts having a length half the path length of the vertical single pipe 42 from the lower end 81 of the vertical single pipe 42 where the heat source 60 is arranged to the end of the cooling material 70 on the side where the heat source 60 is arranged are the heating section 53 and the cooling section 52. In the case of the compound pipe 43, "L hot "+ΔL" is defined as "the piping path length in the portion where natural circulation 111 is occurring," and specifically, this is the length obtained by subtracting the piping path length L1 from the path length of the composite pipe 43 from the vertical pipe end 81 where the heat source 60 is located to the end of the cooling medium 70 on the side where the heat source 60 is located, and adding the natural circulation penetration depth ΔL.

[0198] In contrast, the above-mentioned "piping path length of the portion where natural circulation occurs" may be the length to the generation position 80, which is the center position of the cooling object 70, instead of the length to the end of the cooling object 70 on the side where the heat source 60 is placed. In this case, the L of the horizontal single pipe 41 hot The "L" of the composite pipe 43 is the length from the end of the horizontal single pipe 41 where the heat source 60 is arranged to the generation position 80, which is the center position of the material to be cooled 70. The cooling section 202-1 and the heating section 202-2 of the vertical single pipe 42 are half the length from the bottom end 81 of the vertical single pipe 42 where the heat source 60 is arranged to the generation position 80, which is the center position of the material to be cooled 70.hot "+ΔL" is the length obtained by adding the natural circulation penetration depth ΔL to the piping path length L2.

[0199] In the above embodiment, the material of the pipe 40 is fixed to "stainless steel," but the material of the pipe 40 may be freely selected by the user. However, when allowing the material of the pipe 40 to be freely selected, physical properties dependent on the material of the pipe, such as the pipe material density and pipe material specific heat stored in the physical property table 34, need to be stored in advance in the physical property table 34 for each selectable material.

[0200] In the above embodiment, the distance between the center height of the high temperature layer 55 indicated by the reference numeral 101 and the center height of the low temperature layer 57 indicated by the reference numeral 102 in FIG. 13 is set to the inner diameter D of the pipe 40. i However, this "0.5 times" is merely an example, and the value may be set arbitrarily within the range from less than 1 to more than 0.

[0201] In the above embodiment, in processing the subroutine for natural circulation heat input shown in FIG. 11, first it is determined whether or not it is a horizontal single pipe 41, and then it is determined whether or not it is a vertical single pipe 42. However, this order of determination is only an example, and the order of determination as to whether the shape type is the horizontal single pipe 41, the vertical single pipe 42, or the composite pipe 43 may be any order.

[0202] In the above embodiment, in the processing of the subroutine for the natural circulation heat input shown in Fig. 11, in the processing of Sa10 performed when the heat source 60 is disposed at the horizontal pipe end 82 of the compound pipe 43, the natural circulation heat input calculation unit 22 selects the formulas (6) and (7) which are the model formulas corresponding to the horizontal single pipe 41. On the other hand, even in the processing of Sa10, the natural circulation heat input calculation unit 22 selects the formulas (6) and (11) which are the model formulas corresponding to the vertical single pipe 42 indicated by the piping shape information at that time, as in the processing of Sa8, and sets the natural circulation penetration depth ΔL to "0" without calculating the natural circulation penetration depth ΔL, and sets L hotmay be calculated by subtracting half the length of the cooling object from the piping path length L3, and then formula (11) may be calculated. In this way, when the shape of the piping 40 is specified, a model formula corresponding to the specified shape of the piping 40 can be fixedly selected without referring to the heat source arrangement information.

[0203] In the above embodiment, three types of cooling material 70 can be selected as shown in cooling material table 32 in Fig. 7, but this number of types is just an example, and there may be one type, two types, or four or more types. Also, although dry ice is shown as an example of a cooling medium supplied to cooling material 70, a cooling medium other than dry ice, such as liquid nitrogen, may be used.

[0204] In the above embodiment, an example is shown in which water is frozen to generate a frozen plug, but a liquid other than water may be frozen to generate a frozen plug. In this case, instead of the fixed values ​​stored in the fixed value table 33 and the physical property values ​​stored in the physical property table 34 corresponding to water, the fixed values ​​and physical property values ​​corresponding to the liquid to be frozen must be stored in the fixed value table 33 and the physical property table 34, respectively.

[0205] In the configuration of the above embodiment, in the process of S42 in FIG. 10, the predicted time t p However, depending on how the allowable time indicated by the allowable time information is defined, the predicted time t p However, it may be possible to determine whether the time is less than the permissible time indicated by the permissible time information.

[0206] In the above embodiment, as shown in the process of S28 in FIG. 9, when the heat source 60 is not installed, the natural circulation heat input Q inis set to "0", and in this case, the pipe shape information included in the pipe information is not used. Therefore, the process shown in FIG. 9 may be modified as follows. For example, in the process of S2 in FIG. 8, the user is prompted to select whether or not there is a heat source 60. When input information indicating that there is no heat source 60 is obtained, the input information acquiring unit 11 sets the information indicating that there is no heat source 60 as the heat source arrangement information. Furthermore, instead of performing the processes of S6 to S9, the input information acquiring unit 11 may perform a process of prompting the user to write the total length L of the pipe 40, and generate pipe information that includes the inner diameter and outer diameter of the pipe 40 and the total length L of the pipe 40, but does not include pipe shape information.

[0207] In the above embodiment, the solidification heat quantity Q calculated in the repeated process performed between S22 and S30 in FIG. ice The time t associated with is Δt, 2×Δt, …, with the initial value being “Δt” and the interval being Δt. The solidification heat Q when time t is “0” ice and the heat of solidification Q when time t is "Δt" ice Since Δt is a very short time, the amount of heat is about the same, but the amount of heat Q ice If the above is to be included, the following may be used, for example.

[0208] When time t is "0", the atmospheric heat Q amb is the temperature of pipe 40 at t=0, T metal Since this is the temperature indicated by the initial water temperature information, T in equation (3) metal The value is obtained by substituting the temperature indicated by the initial water temperature information into the sensible heat quantity Q of the pipe 40. m And the sensible heat of water 50 Q f At t=0, there is no temperature change, so the natural circulation heat input Q is "0". in As already mentioned above, at t=0, it becomes "0". Therefore, from equation (1), the solidification heat Q at t=0 is ice is "cooling amount Q ja -Atmospheric heat quantity Q amb "

[0209] Heat of solidification Q at t=0 ice 9 is incorporated into the flowchart of FIG. 9, the following process is performed by the atmospheric heat quantity calculation unit 24 in parallel with the process of S21, for example. That is, the atmospheric heat quantity calculation unit 24 takes in the piping information, initial water temperature information, atmospheric temperature information, and cooling material information output by the input information acquisition unit 11 in the process of S10, and records the taken in piping information, atmospheric temperature information, and cooling material information in an internal storage area. The atmospheric heat quantity calculation unit 24 calculates the temperature indicated by the taken in atmospheric temperature information and the temperature indicated by the taken in initial water temperature information as T amb And, T metal Applying S25 to the same procedure, the atmospheric heat quantity Q amb The atmospheric heat quantity calculation unit 24 calculates the calculated atmospheric heat quantity Q amb The time “0” is associated with this and output to the coagulation heat calculation unit 27.

[0210] The solidification heat quantity calculation unit 27 calculates the atmospheric heat quantity Q associated with the time “0” output by the atmospheric heat quantity calculation unit 24 as a process related to the process of S30. amb When the natural circulation heat input calculation unit 22, the piping sensible heat calculation unit 25, and the water sensible heat calculation unit 26 are input, the cooling amount Q stored in the internal storage area is calculated without waiting for the outputs from the natural circulation heat input calculation unit 22, the piping sensible heat calculation unit 25, and the water sensible heat calculation unit 26. ja The amount of heat Q taken in from the atmosphere amb The heat of solidification at time "0" is subtracted from the value Q ice The coagulation heat quantity calculation unit 27 calculates the calculated coagulation heat quantity Q ice The amount of heat taken in from the atmosphere Q amb The time “0” associated with the time “1” is associated with the predicted time “1” and output to the predicted time calculation unit 14.

[0211] (Computer Configuration) FIG. 17 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The above-mentioned freeze plug generation possibility determination device 1 is implemented in the computer 90. The operations of the above-mentioned processing units, that is, the input information acquisition unit 11, the heat amount calculation unit 13, the predicted time calculation unit 14, and the generation possibility determination unit 15, are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93 and expands it in the main memory 92, and executes the above-mentioned processing according to the program. The processor 91 also secures a memory area corresponding to the above-mentioned memory unit 12 in the main memory 92 or the storage 93 according to the program. The output unit 16 is connected via an interface 94. Therefore, the output unit 16 may or may not be a component of the computer 90, that is, a component of the freeze plug generation possibility determination device 1 as described above.

[0212] The program may be for realizing a part of the functions to be performed by the computer 90. For example, the program may be for realizing the functions by combining with other programs already stored in the storage 93 or by combining with other programs implemented in other devices. In other embodiments, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions to be realized by the processor may be realized by the integrated circuit.

[0213] Examples of the storage 93 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a semiconductor memory. The storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via an interface 94 or a communication line. In addition, when the program is distributed to the computer 90 via a communication line, the computer 90 that receives the program may load the program into the main memory 92 and execute the above-mentioned process. In at least one embodiment, the storage 93 is a non-transitory tangible storage medium.

[0214] <Additional Notes> The freeze plug generation possibility determination device 1 described in the embodiment of the present disclosure can be understood, for example, as follows.

[0215] (1) The freeze plug generation possibility determination device 1 according to the first aspect includes an input information acquisition unit 11 that acquires piping information, which is information about a piping 40 in which a freeze plug (e.g., ice plug 51) is generated by being cooled by a cooling material 70, initial liquid temperature information (e.g., initial water temperature information) indicating the temperature of a liquid (e.g., water 50) in the piping before being cooled by the cooling material, ambient temperature information indicating the temperature of the air around the piping, heat source arrangement information indicating an arrangement state of a heat source 60 that supplies heat to the liquid, cooling material information, which is information about the cooling material, and allowable time information indicating the time allowed for the generation of the freeze plug, and calculates a solidification heat Q supplied to the liquid in the piping based on the piping information, the initial liquid temperature information, the ambient temperature information, the heat source arrangement information, and the cooling material information. ice and a heat quantity calculation unit 13 that calculates a predicted time t until the freeze plug of a predetermined length is generated in the pipe based on the heat quantity of solidification. pand a generation possibility determination unit 15 that determines whether or not the freeze plug can be generated based on the predicted time and the time indicated by the permissible time information. According to this aspect and the following aspects, it is possible to determine whether or not a freeze plug can be generated within a desired time based on a set condition, without actually generating a freeze plug.

[0216] (2) A second aspect of the freeze plug generation possibility determination device 1 is the freeze plug generation possibility determination device 1 of (1), wherein the piping information includes information capable of identifying the outer diameter and inner diameter of the piping and information capable of identifying the total length of the piping, and when the heat source placement information indicates that the heat source is placed, further includes piping shape information indicating the type of shape of the piping and the path length of the piping from the position of the end of the piping where the heat source is placed to the position where the freeze plug is to be generated.

[0217] (3) A third aspect of the freeze plug generation possibility determination device 1 is the freeze plug generation possibility determination device 1 of (2), in which, when the heat source arrangement information indicates that the heat source is arranged, the heat amount calculation unit calculates a natural circulation heat input Q in a natural circulation heat input calculation unit 22 that calculates for each unit time, by applying the piping information, the path length of the piping where the natural circulation occurs, which is derived from the path length of the piping from the position of the end of the piping where the heat source is located to the position where the freeze plug is generated, and the temperature of the liquid, which changes per unit time with the temperature indicated by the initial liquid temperature information as an initial value, to a model formula corresponding to the type of piping shape indicated by the piping shape information, and sets the natural circulation heat input per unit time to zero when the heat source arrangement information indicates that the heat source is not arranged. ice This allows for a more accurate prediction of time t p It is possible to predict the occurrence of a frozen plug, thereby making it possible to determine with greater accuracy whether or not a frozen plug will occur.

[0218] (4) A freeze plug generation possibility determination device 1 according to a fourth aspect is the freeze plug generation possibility determination device 1 of (3), in which the piping shape information is information indicating which type of piping is a horizontal pipe 41, a vertical pipe 42, or a compound pipe 43 in which a horizontal pipe is joined to the upper end of a vertical pipe via an elbow portion. According to this aspect, the natural circulation heat input Q of all shapes of piping 40 having various shapes is calculated according to the shapes of three types of piping 40, namely, the horizontal pipe 41, the vertical pipe 42, and the compound pipe 43. in It becomes possible to calculate

[0219] (5) A fifth aspect of the freeze plug generation possibility determination device 1 is the freeze plug generation possibility determination device 1 of (4), wherein the heat source arrangement information, when the piping shape information indicates either the horizontal single pipe or the compound pipe, is information indicating whether the heat source is arranged at both ends, the heat source is arranged at one end, or the heat source is not arranged at both ends; and when the piping shape information indicates the vertical single pipe, is information indicating either the heat source is arranged at the lower end 81, or the heat source is not arranged at the lower end; and when the heat source arrangement information indicates a state in which the heat source is arranged at both ends, the natural circulation heat input calculation unit calculates the natural circulation heat input per unit time caused by each of the heat sources at both ends. According to this embodiment, in the case of the vertical single pipe 42, in consideration of the phenomenon that the heat source 60 at the upper end 82 does not supply heat to the portion where the freeze plug is generated, the natural circulation heat input Q in In addition, when the heat sources 60 are disposed at both ends, natural circulation occurs due to each of the heat sources 60 at both ends, and the amount of natural circulation heat input Q supplied to the location where the freeze plug is generated by each of these natural circulations is calculated. in The purpose of the calculation is to

[0220] (6) A sixth aspect of the freeze plug generation possibility determination device 1 is the freeze plug generation possibility determination device 1 of (4) or (5), in which, when the lower end of the vertical pipe portion of the compound pipe is called the vertical pipe end 81 and the end of the horizontal pipe portion of the compound pipe that is not joined to the elbow portion is called the horizontal pipe end 82, the natural circulation heat input calculation unit, when the piping shape information indicates the compound pipe, determines that the freeze plug generation position is any location in the horizontal pipe portion of the compound pipe, and the heat source placement information indicates a state in which the heat source is placed at the vertical pipe end. When the piping shape information indicates the composite pipe, the location where the freeze plug was generated is anywhere in the horizontal pipe part of the composite pipe, and the heat source arrangement information indicates a state in which the heat source is arranged at the end of the horizontal pipe, the natural circulation heat input per unit time caused by the heat source is calculated using a model formula corresponding to the single horizontal pipe instead of the model formula corresponding to the composite pipe.

[0221] (7) A seventh aspect of the freeze plug generation possibility determination device 1 is any one of the freeze plug generation possibility determination devices 1 according to (4) to (6), wherein the natural circulation heat input calculation unit, when a model equation corresponding to either the horizontal single pipe or the vertical single pipe is used, calculates the natural circulation heat input per unit time by taking the path length of the piping from the position of the end of the piping at which the heat source to which the model equation is applied is located to the end of the cooling medium on the side at which the heat source is located as the path length of the piping in the portion where the natural circulation is occurring, and calculates the natural circulation heat input per unit time for the composite pipe. In the case where a model formula corresponding to the above is used and the heat source is disposed at the lower end of the vertical pipe portion of the composite pipe, the natural circulation heat input per unit time is calculated by adding the depth to which natural circulation occurring in the horizontal pipe portion of the composite pipe penetrates toward the elbow portion to the path length of the composite pipe from the path length of the composite pipe from the lower end of the vertical pipe portion where the heat source is disposed to the end of the cooling medium on the side where the heat source is disposed, minus the path length of the vertical pipe portion of the composite pipe, to the path length. According to this aspect, the natural circulation heat input Q per unit time can be calculated with higher accuracy by setting the path length of the piping 40 in the part where natural circulation occurs as the end of the cooling medium 70 on the side where the heat source 60 is disposed. in can be calculated.

[0222] (8) The freeze plug generation possibility determination device 1 according to an eighth aspect is any one of the freeze plug generation possibility determination devices 1 according to (3) to (7), and the natural circulation heat input calculation unit calculates the natural circulation heat input amount by regarding the temperature indicated by the initial liquid temperature information as the temperature of the liquid heated by the heat source. According to this aspect, the natural circulation heat input amount Q in can be calculated, so the natural circulation heat input Q in The calculation configuration can be simplified.

[0223] (9) A freeze plug generation possibility determination device 1 according to a ninth aspect is the freeze plug generation possibility determination device 1 of (8), in which when the heat source arrangement information indicates that a plurality of the heat sources are arranged, the input information acquisition unit acquires information indicating the temperature of the liquid that is the warmest among the temperatures of the liquids heated by each of the plurality of the heat sources as the initial liquid temperature information. According to this aspect, even in the case of the eighth aspect described above, by setting the information indicating the temperature of the warmest liquid as the initial liquid temperature information, it is possible to more reliably predict the time when a freeze plug will be generated.

[0224] (10) A freeze plug generation possibility determination device 1 according to a tenth aspect is the freeze plug generation possibility determination device 1 according to any one of (3) to (7), in which, when the heat source arrangement information indicates that a plurality of heat sources are arranged, the input information acquisition unit acquires information indicating each of the temperatures of the liquid heated by each of the plurality of heat sources as heat source heating liquid temperature information (e.g., heat source heating water temperature information) corresponding to each of the plurality of heat sources, and when calculating the natural circulation heat input corresponding to any one of the plurality of heat sources, the natural circulation heat input calculation unit calculates the natural circulation heat input using the temperature indicated by the heat source heating liquid temperature information corresponding to the one heat source. According to this aspect, the temperature of the liquid heated by the heat source 60 can be made different from the temperature indicated by the initial liquid temperature information, so that the natural circulation heat input Q can be calculated with higher accuracy. in can be calculated.

[0225] (11) The freeze plug generation possibility determination device 1 according to an eleventh aspect is any one of the freeze plug generation possibility determination devices 1 according to (3) to (10), wherein the heat amount calculation unit calculates a cooling amount Q by the cooling material based on the cooling material information. jaa temperature calculation unit 23 that calculates the temperature of the liquid per unit time and the temperature of the piping per unit time under the assumption that the temperature of the piping and the temperature of the liquid are the same based on the cooling amount, the natural circulation heat input per unit time, the initial liquid temperature information, and the piping information; and a temperature calculation unit 24 that calculates the surface area of ​​the outside of the piping in contact with the surrounding air based on the piping information and the cooled material information, and calculates the atmospheric heat quantity Q per unit time based on the calculated surface area, the temperature indicated by the atmospheric temperature information, and the temperature of the piping per unit time. amb an atmospheric heat quantity calculation unit 24 that calculates the volume of the material of the piping based on the piping information, and calculates the sensible heat quantity Q of the piping per unit time based on the calculated volume of the material of the piping and the amount of change in the temperature of the piping during the unit time; m a liquid sensible heat calculation unit (e.g., water sensible heat calculation unit 26) that calculates an internal volume of the pipe based on the piping information and calculates a sensible heat Qf of the liquid for each unit time based on the calculated internal volume of the pipe and the amount of change in temperature of the liquid during the unit time; and a solidification heat calculation unit 27 that calculates a solidification heat for each unit time based on the cooling amount, the atmospheric heat for each unit time, the sensible heat of the pipe for each unit time, the sensible heat of the liquid for each unit time, and the natural circulation heat input for each unit time.

[0226] (12) A twelfth aspect of the device 1 for determining whether a freeze plug can be formed is the device 1 for determining whether a freeze plug can be formed of (11), wherein the predicted time calculation unit calculates the predicted time based on an arithmetic formula that has as a variable the thickness of the solid that forms the freeze plug, and that expresses the reciprocal of the generation rate of the solid that forms the freeze plug in each of the unit times using the inner diameter of the pipe identified by the piping information, the specified length, the density of the liquid, the heat of solidification of the liquid per unit mass, and the heat of solidification per unit time.

[0227] (13) A thirteenth aspect of the device 1 for determining whether a freeze plug can be generated is any one of the devices 1 for determining whether a freeze plug can be generated (1) to (12), wherein the predicted time calculation unit calculates, based on the cooling material information, the length of the part of the pipe that is covered by the cooling material in the central axial direction of the pipe as the specified length. [Explanation of symbols]

[0228] 1...Determination device for whether or not freezing plug generation is possible 11...Input information acquisition section 12...Storage section 13…Calorie calculation part 14...Predicted time calculation section 15... Generation possibility determination unit 16...Output section 21…Cooling amount calculation section 22…Natural circulation heat input calculation section 23...Temperature calculation section 24…Atmospheric heat calculation section 25…Pipe sensible heat calculation section 26...Water sensible heat calculation section 27…solidification heat amount calculation section 31...Piping specification table 32…Refrigerated item table 33…Fixed Value Table 34...Physical property table 40…Pipe 41...Horizontal single pipe 42...Vertical single pipe 43…Composite pipe 50…Water 51…Ice plug 60…Heat source 70,70-1,70-2…cooling material

Claims

1. an input information acquisition unit that acquires piping information, which is information about a piping in which a freeze plug is generated by being cooled by a cooling material, initial liquid temperature information, which indicates the temperature of the liquid in the piping before being cooled by the cooling material, ambient temperature information, which indicates the temperature of the air surrounding the piping, heat source arrangement information, which indicates the arrangement of a heat source that supplies heat to the liquid, cooling material information, which is information about the cooling material, and allowed time information, which indicates the time allowed for the generation of the freeze plug; a heat quantity calculation unit that calculates a solidification heat quantity supplied to the liquid in the pipe based on the pipe information, the initial liquid temperature information, the atmospheric temperature information, the heat source arrangement information, and the cooling material information; a predicted time calculation unit that calculates a predicted time for the freeze plug of a predetermined length to be generated in the pipe based on the amount of heat of solidification; A generation possibility determination unit that determines whether or not the freeze plug can be generated based on the predicted time and the time indicated by the permissible time information; A device for determining whether or not a freeze plug can be generated.

2. The piping information includes The heat source arrangement information includes information that can specify the outer diameter and inner diameter of the pipe, and information that can specify the total length of the pipe, and when the heat source arrangement information indicates that the heat source is arranged, the heat source arrangement information further includes pipe shape information that indicates the type of shape of the pipe, and a path length of the pipe from the position of the end of the pipe where the heat source is arranged to the generation position of the freeze plug. The device for determining whether or not a frozen plug can be generated according to claim 1 .

3. The heat amount calculation unit is When the heat source arrangement information indicates that the heat source is arranged, a natural circulation heat input amount, which is the amount of heat supplied to a location where the freeze plug is generated by natural circulation caused in the liquid in the piping by the heat source, is calculated for each unit time by applying the piping information, the path length of the piping in the portion where the natural circulation is occurring, which is derived from the path length of the piping from the position of the end of the piping where the heat source is arranged to the position where the freeze plug is generated, and the temperature of the liquid, which changes for each unit time using the temperature indicated by the initial liquid temperature information as an initial value, to a model formula corresponding to the type of shape of the piping indicated by the piping shape information; a natural circulation heat input amount calculation unit that sets the natural circulation heat input amount per unit time to zero when the heat source arrangement information indicates that the heat source is not arranged The device for determining whether or not a frozen plug can be generated as described in claim 2.

4. The pipe shape information is This information indicates whether the pipe is a single horizontal pipe, a single vertical pipe, or a compound pipe in which a horizontal pipe is joined to the upper end of a vertical pipe via an elbow. The device for determining whether or not a frozen plug can be generated according to claim 3.

5. The heat source arrangement information is When the piping shape information indicates either the horizontal single pipe or the compound pipe, the piping shape information indicates whether the piping shape information indicates a state in which the heat source is disposed at both ends, a state in which the heat source is disposed at one end, or a state in which the heat source is not disposed at both ends, When the piping shape information indicates the vertical single pipe, the piping shape information indicates either a state in which the heat source is disposed at a lower end or a state in which the heat source is not disposed at a lower end, The natural circulation heat input calculation unit When the heat source arrangement information indicates a state in which the heat sources are arranged at both ends, a natural circulation heat input amount per unit time caused by each of the heat sources at both ends is calculated. The device for determining whether or not a frozen plug can be generated according to claim 4.

6. When the lower end of the vertical pipe portion of the compound pipe is referred to as the vertical pipe end, and the end of the horizontal pipe portion of the compound pipe that is not joined to the elbow portion is referred to as the horizontal pipe end, The natural circulation heat input calculation unit When the piping shape information indicates the compound pipe, the freeze plug generation position is at any location in the horizontal pipe portion of the compound pipe, and the heat source arrangement information indicates a state in which the heat source is arranged at the end of the vertical pipe, the natural circulation heat input per unit time caused by the heat source is calculated using a model formula corresponding to the compound pipe, When the piping shape information indicates the compound pipe, the freeze plug generation position is at any location in the horizontal pipe portion of the compound pipe, and the heat source arrangement information indicates a state in which the heat source is arranged at the end of the horizontal pipe, the natural circulation heat input amount per unit time caused by the heat source is calculated using a model formula corresponding to the single horizontal pipe instead of a model formula corresponding to the compound pipe. The device for determining whether or not a frozen plug can be generated according to claim 4.

7. The natural circulation heat input calculation unit When a model formula corresponding to either the horizontal single pipe or the vertical single pipe is used, the path length of the piping from the end position of the piping where the heat source to which the model formula is applied is located to the end of the cooling object on the side where the heat source is located is defined as the path length of the piping in the portion where the natural circulation occurs, and the natural circulation heat input amount per unit time is calculated; In the case where a model equation corresponding to the composite pipe is used and the heat source is disposed at a lower end of a vertical pipe portion of the composite pipe, the natural circulation heat input amount per unit time is calculated by adding a path length obtained by subtracting the path length of the vertical pipe portion of the composite pipe from the path length of the composite pipe from the lower end of the vertical pipe portion where the heat source is disposed to the end of the cooling object on the side where the heat source is disposed, to a depth to which natural circulation generated in a horizontal pipe portion of the composite pipe penetrates toward the elbow portion, as the path length of the piping in the portion where the natural circulation occurs. The device for determining whether or not a frozen plug can be generated according to claim 4.

8. The natural circulation heat input calculation unit calculating the natural circulation heat input amount by regarding the temperature indicated by the initial liquid temperature information as the temperature of the liquid heated by the heat source; The device for determining whether or not a frozen plug can be generated according to claim 3.

9. When the heat source arrangement information indicates that a plurality of the heat sources are arranged, The input information acquisition unit acquiring, as the initial liquid temperature information, information indicating a temperature of the liquid that is the highest among temperatures of the liquid heated by each of the plurality of heat sources; The device for determining whether or not a frozen plug can be generated according to claim 8.

10. When the heat source arrangement information indicates that a plurality of the heat sources are arranged, The input information acquisition unit acquiring information indicating each of the temperatures of the liquid heated by each of the plurality of heat sources as heat source heated liquid temperature information corresponding to each of the plurality of heat sources; The natural circulation heat input calculation unit When calculating the natural circulation heat input amount corresponding to any one of the plurality of heat sources, the natural circulation heat input amount is calculated using a temperature indicated by the heat source heating liquid temperature information corresponding to the one heat source. The device for determining whether or not a frozen plug can be generated according to claim 3.

11. The heat amount calculation unit is a cooling amount calculation unit that calculates a cooling amount by the cooling material based on the cooling material information; a temperature calculation unit that calculates the temperature of the liquid per unit time and the temperature of the piping per unit time based on the cooling amount, the amount of natural circulation heat input per unit time, the initial liquid temperature information, and the piping information under the assumption that the temperature of the piping and the temperature of the liquid are the same temperature; an atmospheric heat quantity calculation unit that calculates an outer surface area of ​​the pipe in contact with the surrounding air based on the pipe information and the cooling material information, and calculates an atmospheric heat quantity per unit time based on the calculated surface area, the temperature indicated by the atmospheric temperature information, and the pipe temperature per unit time; a pipe sensible heat amount calculation unit that calculates a volume of the pipe material based on the pipe information, and calculates a sensible heat amount of the pipe for each unit time based on the calculated volume of the pipe material and an amount of change in the pipe temperature during the unit time; a liquid sensible heat calculation unit that calculates an internal volume of the pipe based on the pipe information, and calculates a sensible heat amount of the liquid per unit time based on the calculated internal volume of the pipe and an amount of change in temperature of the liquid during the unit time; a solidification heat quantity calculation unit that calculates a solidification heat quantity per unit time based on the cooling amount, the atmospheric heat quantity per unit time, the sensible heat quantity of the piping per unit time, the sensible heat quantity of the liquid per unit time, and the natural circulation heat input quantity per unit time; The device for determining whether or not a frozen plug can be generated as described in claim 3.

12. The predicted time calculation unit The predicted time is calculated based on an arithmetic expression which uses a thickness of a solid forming the freeze plug as a variable, and which expresses a reciprocal of a generation rate of a solid forming the freeze plug in each of the unit times using an inner diameter of the pipe specified by the piping information, the predetermined length, the density of the liquid, the heat of solidification of the liquid per unit mass, and the heat of solidification per unit time. The device for determining whether or not a frozen plug can be generated according to claim 11.

13. The predicted time calculation unit calculating, based on the coolant information, a length of the pipe in a central axis direction of the pipe that is covered with the coolant as the predetermined length; The device for determining whether or not a frozen plug can be generated according to claim 1 .

14. acquiring piping information, which is information about a pipe in which a freeze plug is generated by being cooled by a cooling material, initial liquid temperature information, which indicates the temperature of the liquid in the pipe before being cooled by the cooling material, ambient temperature information, which indicates the temperature of the air surrounding the pipe, heat source arrangement information, which indicates the arrangement state of a heat source that supplies heat to the liquid, cooling material information, which is information about the cooling material, and allowable time information, which indicates the time allowed for the generation of the freeze plug; calculating an amount of heat of solidification supplied to the liquid in the pipe based on the pipe information, the initial liquid temperature information, the ambient temperature information, the heat source arrangement information, and the cooling material information; Calculating a predicted time for a predetermined length of the freeze plug to be generated in the pipe based on the amount of heat of solidification; A step of determining whether or not the freeze plug can be generated based on the predicted time and the time indicated by the allowable time information; A method for determining whether or not a freeze plug has been generated, comprising:

15. acquiring piping information, which is information about a pipe in which a freeze plug is generated by being cooled by a cooling material, initial liquid temperature information, which indicates the temperature of the liquid in the pipe before being cooled by the cooling material, ambient temperature information, which indicates the temperature of the air surrounding the pipe, heat source arrangement information, which indicates the arrangement state of a heat source that supplies heat to the liquid, cooling material information, which is information about the cooling material, and allowable time information, which indicates the time allowed for the generation of the freeze plug; calculating an amount of heat of solidification supplied to the liquid in the pipe based on the pipe information, the initial liquid temperature information, the ambient temperature information, the heat source arrangement information, and the cooling material information; Calculating a predicted time for a predetermined length of the freeze plug to be generated in the pipe based on the amount of heat of solidification; A step of determining whether or not the freeze plug can be generated based on the predicted time and the time indicated by the allowable time information; A program that causes a computer to execute the following.

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