Pipe cooling system and pipe cooling method

Abstract

A pipe cooling system and a pipe cooling method are provided that effectively suppress the occurrence of thermal cracks in concrete. [Solution] A registration control unit (301) pre-registers analysis temperatures from the start of concrete curing to the end of curing as pre-analysis values. A supply control unit (302) supplies refrigerant from a cooling pipe pre-installed inside the concrete during curing. An acquisition control unit (303) acquires detected temperatures from the start of concrete curing as actual values ​​using a temperature sensor pre-installed in the concrete. A calculation control unit (304) calculates the gradient of the pre-analysis value at a predetermined time from the start of concrete curing and the gradient of the actual value at that time. A determination control unit (305) compares the calculated actual value with the gradient of the pre-analysis value to determine whether the actual value has a steeper gradient than the pre-analysis value. A temperature control unit (306) controls the refrigerant temperature if the actual value has a steeper gradient than the pre-analysis value.

Description

[Technical Field]

[0001] The present invention relates to a pipe cooling system and a pipe cooling method. [Background technology]

[0002] Conventionally, when pouring mass concrete (also simply called concrete) that is made up of large blocks and has a large volume and weight, the weight and volume of the concrete cause the heat of hydration generated by the reaction between the cement and water in the concrete during curing to accumulate, which has the problem of making the concrete prone to thermal cracking (also called thermal stress cracking) due to the expansion and contraction of the concrete during curing.

[0003] Therefore, a technology called pipe cooling exists to prevent thermal cracking of concrete. In this pipe cooling, pipes are installed inside the formwork into which the ready-mixed concrete will be filled, and when the formwork is filled with the ready-mixed concrete, a refrigerant (also called a cooling medium or solvent) is run through the pipes to control the temperature and flow rate of the refrigerant, thereby appropriately cooling the concrete during curing. This is said to prevent the occurrence of thermal cracking of concrete. Once the concrete has cured, the pipes are filled tightly with non-shrinkage mortar or similar, completing the pipe cooling process.

[0004] Many types of technologies related to pipe cooling have been developed. For example, Japanese Patent Application Laid-Open Publication No. 2017-036546 (Patent Document 1) discloses a real-time visualization method for temperature measurement information in a pipe cooling system for a concrete structure. This real-time visualization method measures the internal and surface temperatures of the concrete structure, as well as the temperature of the cooling water passing through it, while also measuring the amount and temperature of the cooling water supplied to the cooling pipe at each key location. Next, the real-time visualization method sends each measurement data to a control device and allows each party to view and understand the data on various devices owned by the parties. The real-time visualization method also registers the predicted temperature history of the concrete based on the results of a preliminary analysis in the control device, and displays each measurement data and the results of the preliminary analysis on each party's various devices, allowing them to compare and consider the data. Furthermore, in the real-time visualization method, if there is a risk that the preset upper and lower alarm limits for the water temperature and flow rate will be exceeded, or if an abnormality such as a power outage occurs, the alarm notification means will immediately notify the various devices owned by each party of the abnormality and prompt them to take action. This allows each person in charge to become aware of the abnormality before or immediately after it occurs, identify its cause, and make improvements to ensure the normal operation of the pipe cooling system.

[0005] Furthermore, Japanese Patent Application Laid-Open Publication No. 2022-150695 (Patent Document 2) discloses a concrete curing apparatus. The concrete curing apparatus includes a temperature data acquisition unit, a parameter acquisition unit, and a parameter control unit. First, the temperature data acquisition unit acquires temperature data of the concrete after pouring. Next, the parameter acquisition unit acquires the flow rate and temperature of the refrigerant supplied to the cooling pipe installed inside the concrete as parameters for controlling and cooling the temperature of the concrete. The parameter control unit controls parameters based on the temperature transition data for the concrete to follow, which was acquired through preliminary analysis. Furthermore, the parameter control unit divides the period from the start time to the end time of the temperature transition data for the control into multiple sections at predetermined time intervals before and after the peak time, which is the time it takes to reach the peak temperature, and sets a constant target temperature for each of the multiple sections according to the temperature change in each of the multiple sections, thereby controlling the parameters. This allows the parameters for cooling the concrete to be controlled based on the temperature transition data for the concrete, thereby more reliably cooling the concrete.

[0006] Japanese Patent Application Laid-Open Publication No. 2022-150701 (Patent Document 3) discloses a concrete curing apparatus. The concrete curing apparatus includes an estimation unit, a control unit, a setting unit, and a generation unit. The estimation unit uses a heat conduction equation to estimate temperature distribution data for the concrete temperature over the curing time after pouring. The control unit then controls the flow rate and temperature of the refrigerant supplied to the cooling pipes installed inside the poured concrete based on a temperature distribution curve plotted with the estimated temperature distribution data. The setting unit then sets an upper limit temperature that is a predetermined temperature higher than the temperature distribution curve and a lower limit temperature that is a predetermined temperature lower than the temperature distribution curve for the time after the peak temperature is reached in the temperature distribution curve. The generation unit then generates an upper limit temperature distribution curve and a lower limit temperature distribution curve based on the set upper limit temperature and lower limit temperature, and the control unit controls the flow rate and temperature of the refrigerant so that the concrete temperature transitions between the upper limit temperature distribution curve and the lower limit temperature distribution curve. This allows the parameters for cooling the concrete to be controlled based on the temperature transition data for managing the concrete, making it possible to cool the concrete more reliably. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2017-036546 [Patent Document 2] Japanese Patent Publication No. 2022-150695 [Patent Document 3] Japanese Patent Publication No. 2022-150701 Summary of the Invention [Problem to be solved by the invention]

[0008] Incidentally, in pipe cooling, as in the techniques described in the above-mentioned Patent Documents 1 to 3, a method of controlling the temperature of the refrigerant by setting upper and lower limit values ​​for management on the analysis temperature (also called predicted temperature history, management temperature transition data, or temperature distribution curve) from the start to the end of concrete curing can be implemented relatively easily.

[0009] However, control methods using upper and lower limits have the problem of excessive or insufficient cooling of the curing concrete. For example, if the temperature of the curing concrete exceeds the upper limit, and control is performed to lower the refrigerant temperature, a certain time lag occurs before the lowered temperature refrigerant circulates through the pipes and cools the curing concrete. As a result, the curing concrete continues to accumulate heat of hydration without being cooled due to the time lag. As a result, the temperature of the curing concrete actually exceeds the upper limit, resulting in thermal cracks in the concrete.

[0010] On the other hand, if the temperature of the concrete during curing falls below the lower limit, the same thing happens. If control is performed to raise the temperature of the refrigerant, as described above, there is a time lag before the heated refrigerant flows through the pipes, circulates around the concrete during curing, and recovers from its excessively cooled state. As a result, the concrete during curing continues to cool more than necessary due to the time lag. As a result, the temperature of the concrete during curing falls far below the lower limit, and as a result, thermal cracks occur in the concrete, as described above.

[0011] As described above, in pipe cooling, the control method using upper and lower limit values ​​has the problem of adversely affecting the quality of the concrete.

[0012] Another possible method for pipe cooling, as in the technology described in Patent Document 2, is to divide temperature transition data into predetermined time intervals and set a target temperature for each interval. However, this method controls the flow rate and temperature of the refrigerant when the actual temperature of the concrete during curing exceeds or is likely to exceed the target temperature for each interval. Even in this case, there is a time lag before the controlled refrigerant has an effect on the concrete during curing, which, as mentioned above, can have a negative impact on the quality of the concrete.

[0013] On the other hand, taking the above-mentioned time lag into consideration, it is also possible to set the upper and lower limit values ​​used in pipe cooling smaller than the analysis temperature to allow for some leeway in refrigerant control. However, in this case, the temperature difference (control width) between the upper and lower limit values ​​becomes narrower, and the refrigerant control switches frequently, which places a burden on the cooling device.

[0014] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a pipe cooling system and a pipe cooling method that can effectively suppress the occurrence of thermal cracks in concrete by focusing on changes in the temperature gradient of concrete during curing. [Means for solving the problem]

[0015] The pipe cooling system according to the present invention comprises a registration control unit, a supply control unit, an acquisition control unit, a calculation control unit, a determination control unit, and a temperature control unit. The registration control unit pre-registers analysis temperatures from the start of concrete curing to the end of curing as preliminary analysis values. The supply control unit supplies refrigerant in a cooling pipe pre-placed inside the concrete during curing. The acquisition control unit acquires detected temperatures from the start of concrete curing as actual values ​​using a temperature sensor pre-installed in the concrete. The calculation control unit calculates the gradient of the preliminary analysis value at a predetermined time from the start of concrete curing and the gradient of the actual value at that time. The determination control unit compares the calculated gradient of the actual value with the calculated gradient of the preliminary analysis value to determine whether the actual value is steeper than the preliminary analysis value. The temperature control unit controls the temperature of the refrigerant when the actual value is steeper than the preliminary analysis value.

[0016] The pipe cooling method according to the present invention includes a registration control step, a supply control step, an acquisition control step, a calculation control step, a determination control step, and a temperature control step, where each control step of the pipe cleaning method corresponds to each control unit of the pipe cleaning system according to the present invention. [Effects of the Invention]

[0017] According to the present invention, by focusing on the change in the temperature gradient of concrete during curing, it is possible to effectively suppress the occurrence of thermal cracks in concrete. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram of a pipe cooling system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a control system for a pipe cooling system according to an embodiment of the present invention. [Figure 3] 1 is a functional block diagram of a pipe cooling system according to an embodiment of the present invention. FIG. [Figure 4]3 is a flowchart showing the procedure for executing the pipe cooling method according to the first embodiment of the present invention. [Figure 5] 4 is a graph showing changes over time in the temperature of concrete and the temperature of a refrigerant during curing when the pipe cooling system according to the first embodiment of the present invention is used. [Figure 6] 10 is a flowchart showing the procedure for executing a pipe cooling method according to a second embodiment of the present invention. [Figure 7] 10 is a graph showing the change over time in the temperature of concrete and the temperature of a refrigerant during curing when a pipe cooling system according to a second embodiment of the present invention is used. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings to help understand the present invention. Note that the following embodiment is an example of the present invention, and is not intended to limit the technical scope of the present invention.

[0020] Now, as shown in FIG. 1, a pipe cooling system 1 according to an embodiment of the present invention includes concrete C, a water supply unit 10, a mixing water tank 20, a cooling device 30, and a control system 40.

[0021] Here, concrete C means mass concrete, and is used for, for example, building foundations, roads, walls, dams, tunnels, bridges, etc. In FIG. 1, concrete C constitutes, for example, the side walls of a box culvert. Here, in order to increase the strength and durability of concrete C, concrete curing (also simply referred to as curing) is carried out after pouring, in which the concrete C is kept at an appropriate temperature and humidity.

[0022] Now, cooling pipes P are laid in a bellows-like pattern inside the concrete C during curing. There are no particular limitations on the type of cooling pipe P, but it can be, for example, a thin-walled steel pipe with a diameter of 25 mm. Temperature sensors for measuring the temperature of the concrete C are installed in advance at predetermined positions inside the concrete C during curing. In Figure 1, two temperature sensors S1 and S2 are installed at two locations near the center of the concrete C during curing. Here, the temperature sensors S1 and S2 can be, for example, thermocouples.

[0023] The water supply unit 10 also supplies the refrigerant to the inside of the cooling pipe P. The water supply unit 10 is provided with a flow rate adjustment valve 10a that adjusts the flow rate of the refrigerant, and the user sets the flow rate of the refrigerant by adjusting the flow rate adjustment valve 10a, and the flow rate of the refrigerant is set appropriately depending on the size of the concrete C and the curing conditions. The flow rate of the refrigerant is set, for example, within a range of 10 L / min to 20 L / min. The refrigerant is not particularly limited, and examples thereof include water, liquids other than water, and gases such as air and gas.

[0024] Furthermore, the upstream supply pipe of the water supply unit 10 is connected to the inlet of the cooling pipe P, and the downstream supply pipe of the water supply unit 10 is connected to the outlet of the cooling pipe P. The water supply unit 10 supplies refrigerant to the upstream supply pipe, where it flows through the cooling pipe P and is sent to the downstream supply pipe. Furthermore, a temperature and flow rate sensor S3 that measures the temperature and flow rate of the refrigerant is installed in advance at a predetermined position on the upstream supply pipe, and a temperature sensor S4 that measures the temperature of the refrigerant is installed in advance at a predetermined position on the downstream supply pipe.

[0025] Furthermore, mixing tank 20 adjusts the temperature of the refrigerant by mixing the refrigerant sent from the downstream supply pipe of water supply unit 10 with the refrigerant cooled by cooling device 30. Here, mixing tank 20 is pre-installed with water supply side pump 20a that sends the refrigerant in the tank to water supply unit 10, and cooling side pump 20b that sends the refrigerant in the tank to cooling device 30. Also, a temperature sensor S5 that measures the temperature of the refrigerant is pre-installed inside mixing tank 20.

[0026] The cooling device 30 cools the refrigerant sent out from the mixing water tank 20 and sends it back to the mixing water tank 20. Here, the cooling upstream pipe of the cooling device 30 is connected to the cooling-side pump 20b, and the cooling-side downstream pipe of the cooling device 30 is installed in the mixing water tank 20. A temperature sensor S6 for measuring the temperature of the refrigerant is installed in advance at a predetermined position on the cooling upstream pipe, and a temperature sensor S7 for measuring the temperature of the refrigerant is installed in advance at a predetermined position on the cooling downstream pipe.

[0027] The control system 40 is electrically connected to the cooling device 30 via signal lines, receives and processes data from the above-mentioned sensors, and controls the cooling device 30.

[0028] Next, the control system 40 of the pipe cooling system 1 according to the embodiment of the present invention will be described in more detail. As shown in Fig. 2, the control system 40 includes a data collector 400, a terminal device 401, a display device 402, a communication device 403, a control device 404, and a switching device 405.

[0029] Here, data collector 400 refers to the parent device of the data logger, and data transmitter 400a refers to the child device of the data logger corresponding to data collector 400. Data transmitter 400a is pre-installed in each of the temperature sensors S1, S2, S4, S5, S6, and S7 and the temperature and flow rate sensor S3. Data collector 400 communicates wirelessly with data transmitter 400a and collects data from each of temperature sensors S1, S2, S4, S5, S6, and S7 and the temperature and flow rate sensor S3 via data transmitter 400a.

[0030] Furthermore, the terminal device 401 records the data collected via the data collector 400. Here, the terminal device 401 is a general computer, such as a small personal computer.

[0031] Furthermore, the display device 402 displays data (such as temperature) acquired by the terminal device 401 and displays results recorded by the terminal device 401. Here, the display device 402 can be, for example, a small display electrically connected to the terminal device 401.

[0032] Furthermore, the communication device 403 is communicably connected to an external terminal device or a network, and transmits data from the terminal device 401. Here, the communication device 403 can be, for example, a mobile router that can be communicatively connected to the Internet using a mobile phone line.

[0033] Furthermore, the control device 404 receives data from the terminal device 401, judges the data, and sends an instruction signal to the switching device 405. Here, the control device 404 can be, for example, a PLC (Programmable Logic Controller).

[0034] The switching device 405 also controls the temperature of the refrigerant by electrically switching between starting and stopping the cooling device 30 based on an instruction signal from the control device 404. Here, the switching device 405 can be, for example, a relay that can switch the electrical circuit of the cooling device 30 on and off using an electrical signal.

[0035] The control system 40 incorporates a CPU, ROM, RAM, HDD, SSD, etc. (not shown), and the CPU uses, for example, the RAM as a work area to execute programs stored in the ROM, HDD, SSD, etc. Furthermore, each control unit (described later) is realized by the CPU executing a program.

[0036] Next, the configuration and execution procedure according to an embodiment of the present invention will be described with reference to Figures 3 to 5. Here, a first embodiment of the present invention will be described. First, a user of the pipe cooling system 1 analyzes the analysis temperature of the concrete C during curing from the curing start time ts to the curing end time te as a pre-analysis value based on information about the site where the concrete C is poured (Figure 4: S101).

[0037] Here, there is no particular limitation on the method of analyzing the pre-analysis values, but for example, a user inputs on-site information about the curing of concrete C into specified simulation software, and inputs into the simulation software the conditions for arranging cooling pipes P in a specified configuration in a formwork, pouring concrete C into the formwork, and flowing a refrigerant through the cooling pipes P at a specified flow rate. The simulation software then outputs, as pre-analysis values, the analysis temperatures of concrete C during curing from the curing start time ts to the curing end time te when concrete C is cured. This makes it possible to check the temperature changes of concrete C in advance, before curing concrete C.

[0038] Here, there is no particular limitation on the arrangement of the cooling pipes P, and as shown in Fig. 1, the cooling pipes P may be arranged in a bellows-like manner inside the concrete C, or may be arranged vertically from the top to the bottom of the concrete C. The arrangement of the cooling pipes P is designed as appropriate according to the desired specifications and conditions of the concrete C.

[0039] Now, when the user completes the analysis of the preliminary analysis values, the user next determines the curing specifications for concrete C based on the preliminary analysis values ​​of concrete C (FIG. 4: S102).

[0040] Here, there is no particular limitation on the method for determining the curing specifications, but for example, the user checks the preliminary analysis values ​​of the concrete C and determines the diameter and size of the cooling pipes P, the arrangement form, the refrigerant flow rate conditions, the refrigerant temperature conditions, the curing period, etc. so as to prevent thermal cracks from occurring in the concrete C. The user also prepares the cooling pipes P, sets the refrigerant flow rate conditions in the water supply unit 10, and sets the refrigerant temperature conditions in the cooling device 30. This completes the preliminary preparations for curing the concrete C.

[0041] Here, the refrigerant temperature conditions of the cooling device 30 are not particularly limited, but examples include temperature conditions in which the refrigerant temperature is adjusted to a set temperature for each of a predetermined number of stages (levels) based on a pre-analysis value of the concrete C. For example, if the refrigerant temperature conditions are divided into three stages, the set temperature is set to 20 degrees in the first stage, 15 degrees in the second stage, and 10 degrees in the third stage. Then, the cooling device 30 can switch to one of the three stages in response to an instruction from the control system 40, and adjust the refrigerant temperature to the set temperature of the stage after the switch.

[0042] When the user inputs the preliminary analysis values ​​of the concrete C to the control system 40, the registration control unit 301 of the control system 40 registers the input preliminary analysis values ​​in advance. This makes it possible to use the preliminary analysis values ​​to control the cooling of the concrete C during curing. Furthermore, the registration control unit 301 registers the curing start time ts and the curing end time te of the concrete C from the input preliminary analysis values, and these can be used to control the cooling of the concrete C during curing.

[0043] Now, once the user has completed determining the curing specifications, the user then goes to the site, makes advance preparations, and starts pouring the concrete C (FIG. 4: S103).

[0044] Here, the method for starting pouring of the concrete C is not particularly limited. For example, the user goes to the construction site and installs the water supply unit 10, the mixing tank 20, the cooling device 30, and the control system 40. Next, prior to pouring the concrete C, the user assembles a predetermined formwork, strings rebar inside the formwork, and uses the rebar to arrange cooling pipes P of a desired diameter and size in a predetermined configuration inside the formwork. Then, to detect the temperature of the concrete C, the user uses the cooling pipes P and rebar to place temperature sensors S1 and S2 in predetermined positions. Furthermore, the user installs the temperature and flow rate sensor S3 and temperature sensor S4 of the water supply unit 10, the temperature sensor S5 of the mixing tank 20, and the temperature sensors S6 and S7 of the cooling device 30, and activates the data transmitter 400a for each of the temperature sensors S1, S2, S4, S5, S6, and S7 and the temperature and flow rate sensor S3, so that the data transmitter 400a sequentially sends data from each sensor to the control system 40. The user then fills the mixing tank 20 with refrigerant, activates the water supply pump 20a and cooling pump 20b of the mixing tank 20, and the cooling device 30, and prepares the water supply unit 10 to be able to supply refrigerant at a predetermined temperature. The user then pours ready-mixed concrete into the formwork using a predetermined concrete tool, thereby filling it with the concrete C. Then, curing of the poured concrete C begins.

[0045] Now, when the user completes pouring the concrete C, the user then operates the pipe cooling system 1 to start cooling the concrete C (FIG. 4: S104).

[0046] Here, there is no particular limitation on the method for starting cooling of the concrete C, but for example, when the user starts the operation of the water supply unit 10, the water supply unit 10 supplies the refrigerant in the cooling pipe P that has been placed in advance inside the concrete C that is being cured. In this way, the water supply unit 10 functions as a supply control unit 302. Furthermore, the refrigerant to be supplied is supplied to the cooling pipe P at a predetermined temperature Tc (for example, 20 degrees in the first stage) according to the refrigerant temperature conditions of the cooling device 30, for example.

[0047] Here, there are no particular limitations on the refrigerant temperature conditions set in the cooling device 30. For example, as described below, if the peak Tdp of the detected temperature Td of the concrete C is used to cool the refrigerant, before the detected temperature Td of the concrete C peaks, the refrigerant temperature conditions are set to mode A (refrigerant temperature decrease mode), which decreases the refrigerant temperature, and after the detected temperature Td of the concrete C peaks, the refrigerant temperature conditions are set to mode B (refrigerant temperature increase mode), which increases the refrigerant temperature. In mode A, when a command to decrease the refrigerant temperature is issued, the set temperature is decreased to one step lower than the current set temperature out of three set temperature levels. In mode B, when a command to increase the refrigerant temperature is issued, the set temperature is increased to one step higher than the current set temperature out of three set temperature levels. This allows the refrigerant temperature to be decreased or increased in stages.

[0048] Next, when the user starts operation of the control system 40, the cooling start time when cooling of the concrete C starts is associated with the curing start time ts of the preliminary analysis value Tp, and the cooling end time when cooling of the concrete C is completed is associated with the curing end time te of the preliminary analysis value Tp. Then, the acquisition control unit 303 of the control system 40 uses a temperature sensor S1 pre-installed on the concrete C to acquire the detected temperature Td (degrees) from the curing start time ts (sec) of the concrete C as an actual value. Note that the temperature detected by the temperature sensor S2 pre-installed on the concrete C is used, for example, for user monitoring. This starts monitoring the temperature Td of the concrete C during curing.

[0049] Here, there is no particular limitation on the timing at which the acquisition control unit 303 acquires the actual value, but for example, as shown in Fig. 5, the acquisition control unit 303 acquires the actual value Td at a predetermined interval time dt (sec) from the curing start time ts. Here, the interval time dt is set appropriately depending on the specifications and conditions of the desired concrete C, such as a few seconds, a few minutes, or a few hours. In Fig. 5, the pre-analysis value Tp (degrees) from the curing start time ts is displayed together with the actual value Td.

[0050] Now, when the acquisition control unit 303 acquires the actual value Td of the concrete C, the calculation control unit 304 of the control system 40 calculates the gradient of the pre-analysis value Tp at a predetermined time from the curing start time ts of the concrete C and the gradient of the actual value Td at that time.

[0051] 5, when an actual value Td of concrete C is acquired at a first time point t1, which is an interval dt after the curing start time ts, the calculation control unit 304 calculates a subtraction value dTp (=Tp1-Tp0) as the gradient of the preliminary analysis value Tp by subtracting the temperature (preliminary analysis value) Tp0 at the previous time point ts, which is the interval dt before the first time point t1, from the temperature (preliminary analysis value) Tp1 at the first time point t1. Next, the calculation control unit 304 divides the subtraction value dTp by the interval dt to calculate a division value αTp (=dTp / dt) as the gradient of the preliminary analysis value Tp. Next, the calculation control unit 304 uses a similar method to calculate the gradient of the actual value Td by subtracting the temperature (actual value) Td0 at the previous time ts, which is the interval time dt before the first time t1, from the temperature (actual value) Td1 at the first time point t1 to obtain a subtraction value dTd (=Td1-Td0), and then dividing the subtraction value dTd by the interval time dt to obtain a division value αTd (=dTd / dt) as the gradient of the actual value. This makes it possible to easily calculate the gradient αTp of the preliminary analysis value Tp and the gradient αTd of the actual value Td corresponding to the interval time dt (interval) for acquiring the temperature.

[0052] The above calculation method is merely an example, and the gradient αTp of the preliminary analysis value Tp and the gradient αTd of the actual value Td may be calculated using a general gradient calculation method without depending on the interval time dt.

[0053] Now, when the calculation control unit 304 completes the calculation, the judgment control unit 305 of the control system 40 compares the gradient αTd of the calculated actual value Td with the gradient αTp of the calculated pre-analysis value Tp to determine whether the actual value Td is steeper than the pre-analysis value Tp (FIG. 4: S105).

[0054] Here, the comparison method and judgment method of the judgment control unit 305 are not particularly limited, but for example, the judgment control unit 305 can compare the absolute value of the gradient αTd of the actual value Td with the absolute value of the gradient αTp of the preliminary analysis value Tp to determine whether the absolute value of the gradient αTd of the actual value Td exceeds the absolute value of the gradient αTp of the preliminary analysis value Tp. In this way, by using the absolute value of the gradient αTd of the actual value Td and the absolute value of the gradient αTp of the preliminary analysis value Tp in the judgment process, the judgment control unit 305 can determine in a single judgment process whether the rate of increase of the actual value Td is greater than the rate of increase of the preliminary analysis value Tp (whether the concrete C has not cooled enough) or whether the rate of decrease of the actual value Td is greater than the rate of decrease of the preliminary analysis value Tp (whether the concrete C has cooled excessively), regardless of whether the actual value Td is increasing or decreasing. Furthermore, by comparing the absolute value of the gradient αTd of the actual value Td with the absolute value of the gradient αTp of the preliminary analysis value Tp, it is possible to determine whether the actual value Td has a steeper gradient than the preliminary analysis value Tp using the same process, regardless of whether the actual value Td is on an upward or downward trend.

[0055] Now, at a first time point t1, which is the time interval dt after the curing start time ts, the absolute value of the gradient αTd of the actual value Td is less than or equal to the absolute value of the gradient αTp of the preliminary analysis value Tp, as shown in Fig. 5. Then, the judgment control unit 305 judges that the absolute value of the gradient αTd of the actual value Td does not exceed the absolute value of the gradient αTp of the preliminary analysis value Tp, and that the gradient of the actual value Td is not steeper than that of the preliminary analysis value Tp (Fig. 4: S105 NO).

[0056] In this case, since there is no need to control the refrigerant temperature Tc, the temperature control unit 306 of the control system 40 maintains the refrigerant temperature Tc (FIG. 4: S106).Then, the temperature control unit 306 determines whether the current time t, which has elapsed since the cooling start time ts, has exceeded the cooling end period te (FIG. 4: S107).

[0057] Here, the current time t has not yet exceeded the cooling end period te, so the temperature control unit 306 determines that the current time t has not exceeded the cooling end period te (FIG. 4: S107 NO). In this case, the process returns to S105, where the determination control unit 305 determines whether the absolute value of the gradient αTd of the preliminary analysis value Tp is equal to the absolute value of the gradient αTp of the actual value Td.

[0058] Now, if the temperature of the concrete C rises suddenly at a second time point t2, which is two interval times dt after the first time point t1, the absolute value of the gradient αTd of the actual value Td at the second time point t2 exceeds the absolute value of the gradient αTp of the preliminary analysis value Tp, as shown in Fig. 5. Then, in S105, the determination control unit 305 determines that the actual value Td has a steeper gradient than the preliminary analysis value Tp (Fig. 4: S105 YES). In this case, the temperature of the refrigerant needs to be controlled, so the temperature control unit 306 controls the temperature of the refrigerant.

[0059] Here, there is no particular limitation on the control method of the temperature control unit 306, but for example, the temperature control unit 306 uses the peak Tdp of the performance value Td to determine whether the mode is A or B (FIG. 4: S108).

[0060] Here, there is no particular limitation on the determination method of the temperature control unit 306, but for example, when the gradient αTd of the performance value Td at a predetermined time point becomes a negative value for the first time, the temperature control unit 306 identifies the peak Tdp of the performance value Td using the performance values ​​up to that point. Specifically, the temperature control unit 306 determines whether the gradient αTd of the performance value Td calculated at the current point in time has become a negative value (below 0) for the first time.

[0061] Here, when the gradient αTd is 0 or more, the actual value Td means before the peak Tdp, when the gradient αTd becomes 0, the actual value Td corresponds to the peak Tdp, and when the gradient αTd becomes less than 0 for the first time, the actual value Td means after the peak Tdp.

[0062] If the gradient αTd is not less than 0, that is, if the gradient αTd is equal to or greater than 0, the actual value Td is on an upward trend, and temperature control unit 306 determines that the actual value Td at the current time point (second time point t2) is before the peak Tdp. Then, temperature control unit 306 determines the mode to be A (FIG. 4: S108: YES) and reduces the refrigerant temperature Tc from the current temperature Tc (FIG. 4: S109).

[0063] Here, there are no particular limitations on the method by which temperature control unit 306 lowers the temperature of the refrigerant, but for example, when temperature control unit 306 switches from the current set temperature (first set temperature) (20 degrees) of the three set temperature levels to the set temperature (second set temperature) one level lower (15 degrees) and sends an instruction to cooling device 30, as time passes from second time point t2, the refrigerant temperature Tc drops from 20 degrees to 15 degrees, as shown in Figure 5. This lowers the temperature of the refrigerant by one level, making it possible to promote the cooling of concrete C.

[0064] Once the temperature control unit 306 has lowered the temperature of the refrigerant, the process proceeds to S107, where the temperature control unit 306 again determines whether the current time t has exceeded the cooling end period te (FIG. 4: S107).

[0065] Here, since the current time t has not yet exceeded the cooling end period te, as described above, the temperature control unit 306 determines that the current time t has not exceeded the cooling end period te (FIG. 4: S107 NO), and returns to S105, where it is determined whether the actual value Td has a steeper gradient than the pre-analysis value Tp.

[0066] Meanwhile, at a third time point t3, some time after the second time point t2, the heat of hydration of concrete C decreases, the peak Tdp of the actual value Td appears, and the temperature of concrete C begins to decrease. Then, the temperature control unit 306 switches from mode A to mode B. This makes it possible to control whether the refrigerant temperature increases or decreases depending on the temperature transition status of concrete C.

[0067] Then, at a fourth time point t4, after a further elapse of time from the third time point t3, if the concrete C cools rapidly, the absolute value of the gradient αTd of the actual value Td will again exceed the absolute value of the gradient αTp of the preliminary analysis value Tp, as shown in Fig. 5. Then, in S105, the determination control unit 305 determines that the actual value Td has a steeper gradient than the preliminary analysis value Tp (Fig. 4: S105 YES). In this case, the temperature control unit 306 uses the peak of the actual value Td to determine whether the mode is A or B, as described above (Fig. 4: S108).

[0068] If the current gradient αTd is less than 0, the actual value Td is on a downward trend, and temperature control unit 306 determines that the actual value Td is after the peak Tdp. Then, temperature control unit 306 determines the mode as B mode (FIG. 4: S108 NO) and increases the refrigerant temperature Tc from the current refrigerant temperature Tc (FIG. 4: S110).

[0069] Here, there are no particular limitations on the method by which temperature control unit 306 raises the temperature of the refrigerant, but for example, when temperature control unit 306 switches from the current set temperature (15 degrees) of the current set temperature (second set temperature) to the set temperature (20 degrees) of the next higher set temperature (first set temperature) among three set temperature levels and sends an instruction to cooling device 30, as time passes from fourth time point t4, the refrigerant temperature Tc will now rise from 15 degrees to 20 degrees, as shown in Figure 5. This raises the temperature of the refrigerant by one level, making it possible to cool concrete C more slowly.

[0070] Now, once the temperature control unit 306 has increased the temperature of the refrigerant, the process proceeds to S107 again, where the temperature control unit 306 determines whether the current time t has exceeded the cooling end period te (FIG. 4: S107).

[0071] Here, since the current time t has not yet exceeded the cooling end period te, the process returns to S105 to determine whether the actual value Td has a steeper gradient than the pre-analysis value Tp.

[0072] On the other hand, if the cooling of the concrete C continues for a while and the current time t exceeds the cooling end period te in S107, the temperature control unit 306 determines that the current time t has exceeded the cooling end period te (Figure 4: S107 YES), determines that the cooling of the concrete C has been completed, and completes all processing.

[0073] This makes it possible to prevent the concrete C from being cooled insufficiently or excessively, and effectively suppress the occurrence of thermal cracks in the concrete C.

[0074] Then, when the curing of the concrete C is completed, the user removes the refrigerant from the cooling pipe P and fills the cooling pipe P with non-shrink mortar or the like without leaving any gaps, thereby completing the pipe cooling.

[0075] In the first embodiment of the present invention, when the temperature control unit 306 determines in S108 that the actual value Td is after the peak Tdp, it determines that the mode is B mode (FIG. 4: S108 NO) and increases the refrigerant temperature Tc (FIG. 4: S110), but other control may also be used.

[0076] For example, as shown in FIG. 5, if the point at which the actual value Td becomes steeper than the pre-analysis value Tp occurs after the peak Tdp of the actual value Td, the temperature control unit 306 may delay switching to mode B after a predetermined delay time td has elapsed from the point at which the peak Tdp occurred (e.g., a third point t3), thereby raising the refrigerant temperature Tc from the refrigerant temperature Tc at the time when the delay time td has elapsed, or may suspend control of the refrigerant temperature during the delay time td. Here, the delay time td may be set appropriately depending on the specifications and conditions of the desired concrete C, such as several seconds, several minutes, or several hours. In this way, by delaying switching to mode B or suspending control of the refrigerant temperature, it is possible to prevent insufficient cooling of the concrete C at the peak temperature during curing.

[0077] Incidentally, the method by which the temperature control unit 306 identifies the peak Tdp of the actual value Td is not particularly limited. For example, the temperature control unit 306 may periodically monitor the gradient αTd of the calculated actual value Td and determine the peak Tdp at a predetermined time t n Actual value Td for (n=1, 2, 3, ...) n Gradient αTd n When the temperature controller 306 detects that the temperature t n and the time t n The previous time t going back a predetermined arbitrary time from n-1 The midpoint between these two points is calculated as the peak point of the peak Tdp, and the actual value Td at the peak point can be specified as the peak Tdp. The arbitrary time may be the interval time dt described above or a preset time. n Actual value Td n and the previous time point t n-1 Actual value Td n-1 The peak Tdp may be roughly calculated using the above, or a general peak identification method may be adopted.

[0078] In the first embodiment of the present invention, the refrigerant temperature Tc is controlled only in accordance with the change in the temperature gradient of the concrete C during curing. However, this is not limiting, and the refrigerant temperature Tc may be controlled in accordance with the temperature gradient of the concrete C during curing by adding upper and lower limit values ​​for management purposes to the temperature gradient of the concrete C during curing.

[0079] Specifically, a second embodiment of the present invention will be described with reference to Figures 3, 6, and 7. First, based on on-site information, the user analyzes the analysis temperatures of concrete C during curing from the curing start time ts to the curing end time te as preliminary analysis values ​​(Figure 6: S201), and determines the curing specifications of concrete C based on the preliminary analysis values ​​of concrete C (Figure 6: S202).

[0080] In the second embodiment of the present invention, the registration control unit 301 registers the analyzed preliminary analysis value in advance, and when the user inputs a predetermined threshold value for the preliminary analysis value, the registration control unit 301 registers the sum obtained by adding the threshold value to the preliminary analysis value as a control upper limit value UL (degrees), and registers the subtraction value obtained by subtracting the threshold value from the preliminary analysis value as a control lower limit value LL (degrees). The threshold value is set appropriately, for example, to several degrees or several tens of degrees, depending on the specifications and conditions of the desired concrete C.

[0081] Then, the user starts pouring the concrete C (FIG. 6: S203) and starts cooling the concrete C (FIG. 6: S204). Here, the water supply unit 10 (supply control unit 302) supplies the refrigerant in the cooling pipe P, and the acquisition control unit 303 uses the temperature sensor S1 of the concrete C to acquire the detected temperature Td (degrees) from the curing start time ts of the concrete C as an actual value.

[0082] Then, as shown in Fig. 7, the actual value Td is acquired at a predetermined interval time dt from the curing start time ts. Also, in Fig. 7, the preliminary analysis value Tp (degrees) from the curing start time ts is displayed in accordance with the detected temperature Td.

[0083] Then, first, the determination control unit 305 determines whether or not the acquired performance value Td is equal to or less than the upper limit value UL at a first time point t1 when the interval time dt has elapsed since the curing start time point ts (FIG. 6: S205).

[0084] Here, as shown in FIG. 7, at the first time point t1, the actual value Td is equal to or less than the upper limit value UL, so the judgment control unit 305 judges that the actual value Td is equal to or less than the upper limit value UL (FIG. 6: S205 YES), and then determines whether the actual value Td is equal to or greater than the lower limit value LL (FIG. 6: S206).

[0085] Here again, as shown in FIG. 7, at the first time point t1, the actual value Td is greater than or equal to the lower limit value LL, so the judgment control unit 305 judges that the actual value Td is greater than or equal to the lower limit value LL (FIG. 6: S206 YES), and completes the judgment process using the upper limit value and the lower limit value.

[0086] Next, the calculation control unit 304 calculates the gradient αTp of the preliminary analysis value Tp at a first time point t1 and the gradient αTd of the actual value Td at that time point t1, and the judgment control unit 305 compares the calculated gradient αTd of the actual value Td with the calculated gradient αTp of the preliminary analysis value Tp to determine whether the actual value Td is steeper than the preliminary analysis value Tp (FIG. 6: S207).

[0087] 7, assume that at the first time point t1, the actual value Td has a steeper gradient than the preliminary analysis value Tp, possibly due to a sudden temperature rise of the concrete C during curing for some reason. Then, the determination control unit 305 determines that the actual value Td has a steeper gradient than the preliminary analysis value Tp (FIG. 6: S207: YES), and the temperature control unit 306 uses the peak Tdp of the actual value Td to determine whether it is mode A or mode B (FIG. 6: S208).

[0088] Here, as shown in Fig. 7, at the first time point t1, the actual value Td is before the peak Tdp, so the temperature control unit 306 determines that the mode is A (Fig. 6: S208: YES) and lowers the refrigerant temperature Tc (Fig. 6: S209). Specifically, the temperature control unit 306 switches the set temperature (20°C) of the current stage (first stage) to the set temperature (15°C) of the next stage (second stage), and sends an instruction to the cooling device 30. This makes it possible to quickly respond and appropriately cool the concrete C during curing, even if the temperature of the concrete C during curing rises suddenly.

[0089] Then, the temperature control unit 306 determines whether the current time t has exceeded the cooling end period te (FIG. 6: S210). However, since the current time t has not yet exceeded the cooling end period te in this case, the temperature control unit 306 determines that the current time t has not exceeded the cooling end period te (FIG. 6: S210 NO), and returns to S205, where it is determined whether the actual value Td is equal to or less than the upper limit value UL.

[0090] Now, at the second time point t2, which is the time interval dt after the first time point t1, if the cooling of the concrete C has progressed appropriately, in S205, the judgment control unit 305 determines that the actual value Td is equal to or less than the upper limit value UL (FIG. 6: S205 YES) and determines that the actual value Td is equal to or greater than the lower limit value LL (FIG. 6: S206 YES). Next, the judgment control unit 305 determines that the actual value Td has a slope that is not steeper than the pre-analysis value Tp (FIG. 6: S207 NO). In this case, since there is no need to control the temperature of the refrigerant, the temperature control unit 306 maintains the temperature of the refrigerant (FIG. 6: S211). This allows the cooling of the concrete C to be maintained.

[0091] Now, at a third time point t3, some time after the second time point t2, if the cooling of the concrete C progresses rapidly, in S205, the determination control unit 305 determines that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), but determines that the actual value Td is less than the lower limit LL (FIG. 6: S206 NO). In this case, the temperature control unit 306 increases the refrigerant temperature Tc (FIG. 6: S212). Specifically, the temperature control unit 306 switches the set temperature (15°C) of the current stage (second stage) to the set temperature (20°C) of the next higher stage (first stage) and sends an instruction to the cooling device 30. As a result, if the actual value Td becomes less than the lower limit LL, the refrigerant temperature is increased, and the actual value Td can be controlled to be equal to or greater than the lower limit LL.

[0092] Furthermore, at a fourth time point t4, which is the time interval dt after the third time point t3, if the temperature of the concrete C continues to rise, in S205, the determination control unit 305 determines that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), and determines that the actual value Td is equal to or greater than the lower limit LL (FIG. 6: S206 YES). However, the determination control unit 305 determines that the actual value Td has a steeper slope than the pre-analysis value Tp (FIG. 6: S207 YES). Then, the temperature control unit 306 determines the A mode using the peak of the actual value Td (FIG. 6: S208) and reduces the refrigerant temperature Tc (FIG. 6: S209). Specifically, the temperature control unit 306 in A mode switches the set temperature (20°C) of the current stage (first stage) to the set temperature (15°C) of the next lower stage (second stage) and sends an instruction to the cooling device 30. This makes it possible to quickly respond to a sudden rise in temperature of the concrete C during curing and appropriately cool the concrete C during curing.

[0093] On the other hand, if the rapid temperature rise of the concrete C has not yet subsided at a fifth time point t5, which is the elapsed time interval dt from the fourth time point t4, the determination control unit 305 determines in S205 that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), and determines that the actual value Td is equal to or greater than the lower limit LL (FIG. 6: S206 YES). However, the determination control unit 305 determines that the actual value Td at the fifth time point t5 has a steeper slope than the pre-analysis value Tp at the fifth time point t5 (FIG. 6: S207 YES). Then, the temperature control unit 306 determines the mode to be A using the peak of the actual value Td (FIG. 6: S208), and reduces the refrigerant temperature (FIG. 6: S209). Specifically, the temperature control unit in mode A switches from the set temperature (15 degrees) of the current stage (second stage) to the set temperature (10 degrees) of the stage (third stage) that is one stage lower, and sends an instruction to the cooling device 30. As a result, if a sudden temperature rise in the concrete C during curing continues, it is possible to quickly respond by gradually lowering the temperature of the refrigerant, thereby appropriately cooling the concrete C during curing.

[0094] Furthermore, suppose that a short time has passed since the fifth time point t5, the heat of hydration of concrete C decreases, the peak Tdp of the actual value Td appears, and the temperature of concrete C begins to drop. Then, the temperature control unit 306 switches from mode A to mode B. This makes it possible to control whether the refrigerant temperature increases or decreases depending on the temperature transition status of concrete C.

[0095] Furthermore, at a sixth time point t6, two interval times dt after the fifth time point t5, if the temperature of the concrete C suddenly drops, the determination control unit 305 determines in S205 that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), but determines that the actual value Td is less than the lower limit LL (FIG. 6: S206 NO). In this case, the temperature control unit 306 increases the refrigerant temperature (FIG. 6: S212). Specifically, the temperature control unit 306 in mode B switches the set temperature (10°C) of the current stage (third stage) to the set temperature (15°C) of the next higher stage (second stage) and sends an instruction to the cooling device 30. As a result, even if the temperature of the concrete C suddenly drops and the actual value Td deviates from the lower limit LL, the temperature control unit 306 increases the refrigerant temperature, thereby controlling the actual value Td to be equal to or greater than the lower limit LL.

[0096] Furthermore, at a seventh time point t7, some time after the sixth time point t6, if the temperature rise of the concrete C continues, the determination control unit 305 determines in S205 that the actual value Td has exceeded the upper limit UL (FIG. 6: S205 NO). In this case, the temperature control unit 306 lowers the refrigerant temperature (FIG. 6: S209). Specifically, the temperature control unit 306 switches the set temperature (15°C) of the current stage (second stage) to the set temperature (10°C) of the next stage (third stage) lower, and sends an instruction to the cooling device 30. As a result, even if the temperature of the concrete C appropriately drops and the actual value Td deviates from the upper limit UL, the temperature control unit 306 lowers the refrigerant temperature, thereby controlling the actual value Td to be equal to or less than the upper limit UL.

[0097] Furthermore, at eighth time point t8, which is the elapsed time interval dt from the seventh time point t7, if the temperature of concrete C suddenly drops, in S205, the determination control unit 305 determines that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), and determines that the actual value Td is equal to or greater than the lower limit LL (FIG. 6: S206 YES), but determines that the actual value Td at eighth time point t8 has a steeper slope than the pre-analysis value Tp at eighth time point t8 (FIG. 6: S207 YES). Then, this time, the temperature control unit 306 determines the mode as B mode using the peak of the actual value Td (FIG. 6: S208), and increases the refrigerant temperature (FIG. 6: S212). Specifically, the temperature control unit 306 in mode B switches the set temperature (10 degrees) of the current stage (third stage) to the set temperature (15 degrees) of the next higher stage (second stage), and sends an instruction to the cooling device 30. This makes it possible to quickly respond to a sudden drop in temperature of the concrete C during curing and appropriately suppress the cooling of the concrete C during curing.

[0098] Furthermore, at a ninth time point t9, which is the elapsed time interval dt from the eighth time point t8, if the cooling of the concrete C continues, in S205, the determination control unit 305 determines that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), and determines that the actual value Td is equal to or greater than the lower limit LL (FIG. 6: S206 YES). However, the determination control unit 305 similarly determines that the actual value Td at the ninth time point t9 has a steeper slope than the pre-analysis value Tp at the ninth time point t9 (FIG. 6: S207 YES). Then, the temperature control unit 306 determines the mode as B mode using the peak of the actual value Td (FIG. 6: S208), and increases the refrigerant temperature (FIG. 6: S212). Specifically, the temperature control unit 306 in mode B switches the set temperature (15 degrees) of the current stage (second stage) to the set temperature (20 degrees) of the next higher stage (first stage), and sends an instruction to the cooling device 30. As a result, if the cooling of the concrete C during curing progresses rapidly, it is possible to quickly respond by gradually increasing the temperature of the refrigerant, thereby appropriately suppressing the cooling of the concrete C during curing.

[0099] Furthermore, if the temperature of the concrete C continues to rise at tenth time point t10, some time after ninth time point t9, the determination control unit 305 determines in S205 that the actual value Td has exceeded the upper limit UL (FIG. 6: S205 NO), and the temperature control unit 306 lowers the temperature of the refrigerant (FIG. 6: S209). Specifically, the temperature control unit 306 switches the set temperature (20°C) of the current stage (first stage) to the set temperature (15°C) of the stage one stage lower (second stage). As a result, even if the temperature of the concrete C continues to rise and the actual value Td deviates from the upper limit UL, the temperature control unit 306 lowers the temperature of the refrigerant, thereby making it possible to control the actual value Td to be equal to or lower than the upper limit UL.

[0100] Furthermore, at an eleventh time point t11, which is the time interval dt after the tenth time point t10, if the temperature of the concrete C suddenly drops, in S205, the determination control unit 305 determines that the actual value Td is equal to or less than the upper limit UL (FIG. 6: S205 YES), and determines that the actual value Td is equal to or greater than the lower limit LL (FIG. 6: S206 YES). However, the determination control unit 305 determines that the actual value Td at the eleventh time point t11 ​​has a steeper slope than the pre-analysis value Tp at the eleventh time point t11 ​​(FIG. 6: S207 YES). In this case, the temperature control unit 306 again raises the refrigerant temperature (FIG. 6: S212). Specifically, the temperature control unit 306 in Mode B switches the set temperature (15°C) of the current stage (second stage) to the set temperature (20°C) of the next higher stage (first stage) and sends an instruction to the cooling device 30. This allows for a detailed response even if the temperature of concrete C drops suddenly.

[0101] Now, if the curing of the concrete C continues for a while and the current time t exceeds the cooling end period te in S210, the temperature control unit 306 determines that the current time t has exceeded the cooling end period te (FIG. 6: S210 YES), determines that the cooling of the concrete C has been completed, and completes all processing.

[0102] As shown in Figure 7, although the refrigerant temperature repeatedly increased and decreased, the actual value Td remained appropriately between the upper limit UL and the lower limit LL. This makes it possible to effectively suppress the occurrence of thermal cracks in the concrete C.

[0103] In this way, in the first and second embodiments of the present invention, it is possible to control the temperature of the concrete C so that it does not drop suddenly, which contributes to reducing the tensile stress of the concrete C after pouring and can suppress the occurrence of thermal cracks in the concrete C.

[0104] In the embodiment of the present invention, the pipe cooling system 1 acquires the actual value Td from the temperature sensor S1 to control the temperature of the refrigerant, but it may also use the actual value from the monitoring temperature sensor S2, or the actual value from another sensor to control the temperature of the refrigerant.

[0105] For example, the acquisition control unit 303 of the pipe cooling system 1 may use the temperature and flow rate sensor S3 to acquire the temperature and flow rate of the refrigerant supplied by the water supply unit 10, and may use the temperature sensor S4 to acquire the temperature of the refrigerant returning from the cooling pipe P of the concrete C. The acquisition control unit 303 may also use the temperature sensor S5 to acquire the temperature of the refrigerant inside the mixing tank 20, the temperature sensor S6 to acquire the temperature of the refrigerant supplied to the cooling device 30, and the temperature sensor S7 to acquire the temperature of the refrigerant returning from the cooling device 30. The control system 40 may then use the acquired refrigerant temperature and flow rate to adjust the refrigerant temperature. This allows for more appropriate cooling of the concrete C during curing.

[0106] Furthermore, in an embodiment of the present invention, an outside air temperature sensor and a humidity sensor (not shown) may be further installed, and the acquisition control unit 303 may use the outside air temperature sensor and humidity sensor to acquire the outside air temperature and humidity, and the control system 40 may use the acquired outside air temperature and humidity to adjust the temperature of the refrigerant. This makes it possible to cool the concrete C during curing more appropriately in accordance with the curing environment.

[0107] In the embodiment of the present invention, the determination control unit 305 determines whether the actual value Td is steeper than the preliminary analysis value Tp by determining whether the absolute value of the gradient αTd of the actual value Td exceeds the absolute value of the gradient αTp of the preliminary analysis value Tp. However, this is not limiting, and other gradient comparison and determination methods can be adopted. For example, the determination control unit 305 calculates the gradient angle corresponding to the gradient αTd of the actual value Td and the gradient αTp of the preliminary analysis value Tp from the calculated gradient αTd of the actual value Td and the gradient αTp of the preliminary analysis value Tp, and compares the gradient angle of the actual value Td with the gradient angle of the preliminary analysis value Tp to determine whether the actual value Td is steeper than the preliminary analysis value Tp. Furthermore, the determination control unit 305 calculates a gradient image showing the gradient αTd of the actual value Td and a gradient image showing the gradient αTp of the preliminary analysis value Tp from the calculated gradient αTd of the actual value Td and the gradient αTp of the preliminary analysis value Tp, respectively, and compares the gradient image of the actual value Td with the gradient image of the preliminary analysis value Tp to determine whether the actual value Td has a steeper gradient than the preliminary analysis value Tp. Furthermore, other gradient comparison methods and determination methods may be employed.

[0108] In the embodiment of the present invention, the calculation control unit 304 calculates the time t n Actual value Td n and the previous time point t n-1 Actual value Td n-1 and the interval time dt to calculate the divided value αTd (=dTd / dt) as the gradient of the actual value Td, but this is not limiting and other gradient calculation methods can be adopted. For example, when the calculation control unit 304 calculates the gradient at a predetermined time t n Actual value Td n and the time tn The previous time t, which is the interval time dt back from n-1 Actual value Td n-1 From this, at time t n The prediction time t, which is the time interval dt after n+1 Actual value Td n+1 and estimate the prediction time t n+1 Actual value Td n+1 From time t n Actual value Td n The subtracted value dTd (= Td n+1 -Td n ) and then divide the subtracted value dTd by the interval time dt to obtain a divided value αTd (=dTd / dt) as the gradient of the actual value Td. This makes it possible to detect a sudden rise or fall in the actual value Td in advance and quickly control the refrigerant temperature. n+1 Actual value Td n+1 There is no particular limitation on the estimation method, but examples include linear regression, least squares method, and maximum likelihood estimation method.

[0109] Furthermore, in the embodiment of the present invention, it is assumed that the acquisition control unit 303 reliably acquires the actual value Td using the temperature sensor S1 of the concrete C. However, if for some reason the actual value Td cannot be acquired from the temperature sensor S1, the value of the missing portion for which the actual value Td could not be acquired may be estimated from past actual values ​​Td using the method of estimating the actual value Td as described above, and the estimated value may be acquired as the actual value Td for subsequent processing. Furthermore, if there is a missing value in the actual value Td, the determination process or refrigerant temperature control process at that time may be stopped, and the stopped determination process or refrigerant temperature control process may be resumed when the actual value Td is properly acquired.

[0110] In the embodiments of the present invention, it is assumed that the acquired actual value Td will fall within a predetermined range based on the pre-analysis value Tp. However, if, for some reason, the acquired actual value Td deviates from this range, a predetermined error threshold may be set for the pre-analysis value Tp, and the result obtained by subtracting the error threshold from the pre-analysis value Tp may be used to determine whether the acquired actual value Td is below the lower error limit. Alternatively, the result obtained by adding the error threshold to the pre-analysis value Tp may be used to determine whether the acquired actual value Td exceeds the upper error limit. If the actual value Td is below the lower error limit or exceeds the upper error limit, the control system 40 may display a message indicating that the acquired actual value Td is an error value.

[0111] In the embodiment of the present invention, the water supply unit 20 and the control system 40 are configured to include each control unit, but this is not limiting, and each control unit may be provided in any of the components of the pipe cooling system 1. Also, in the embodiment of the present invention, the steps executed by each control unit may be provided as the pipe cooling method of the present invention. Furthermore, in the embodiment of the present invention, a program that realizes each control unit may be stored in a storage medium, and the storage medium may be provided. In this configuration, the program is read out by a predetermined device, and the device realizes each control unit. In this case, the program itself read out from the recording medium achieves the effects of the present invention. [Industrial Applicability]

[0112] As described above, the pipe cooling system and pipe cooling method according to the present invention are useful in a wide range of fields where concrete is poured, such as the construction field, civil engineering field, and architecture field, and are effective as a pipe cooling system and pipe cooling method that can effectively suppress the occurrence of thermal cracks in concrete by focusing on changes in the temperature gradient of concrete during curing. [Explanation of symbols]

[0113] 1 Pipe cooling system 10 Water Supply Unit 20 Mixed tank 30 Cooling device 40 Control System 301 Registration control section 302 Supply control section 303 Acquisition control section 304 Calculation control unit 305 Judgment control unit 306 Temperature control unit

Claims

1. a registration control unit that registers analysis temperatures from the start of concrete curing to the end of curing as preliminary analysis values ​​in advance; a supply control unit that supplies a refrigerant to a cooling pipe that is pre-placed inside the concrete during curing; an acquisition control unit that acquires, as an actual value, a detected temperature of the concrete from the start of curing using a temperature sensor previously installed in the concrete; a calculation control unit that calculates a gradient of the pre-analysis value, which is a change per unit time in the pre-analysis value, at a time point when a predetermined time has elapsed since the start of curing of the concrete, and a gradient of the actual value, which is a change per unit time in the actual value at that time point; a determination control unit that compares the gradient of the calculated actual value with the gradient of the calculated preliminary analysis value to determine whether the actual value has a steeper gradient than the preliminary analysis value; a temperature control unit that controls the temperature of the refrigerant when the actual value has a steeper gradient than the pre-analysis value; A pipe cooling system equipped with:

2. the determination control unit determines whether or not an absolute value of the gradient of the actual value exceeds an absolute value of the gradient of the pre-analysis value; the temperature control unit controls the temperature of the refrigerant when an absolute value of the gradient of the actual value exceeds an absolute value of the gradient of the pre-analysis value. The pipe cooling system of claim 1 .

3. When calculating the gradient of the pre-analysis value and the gradient of the actual value, the calculation control unit calculates a subtraction value by subtracting the temperature at a time point preceding the time point by a predetermined interval time from the temperature at the time point, and calculates the gradient by dividing the subtraction value by the interval time. The pipe cooling system according to claim 2 .

4. the temperature control unit determines whether the gradient of the currently calculated performance value is less than 0, and if the gradient of the performance value is equal to or greater than 0, determines that the performance value is before a peak, and if the gradient of the performance value is less than 0, determines that the performance value is after a peak; If the time point at which the actual value is determined to have a steeper gradient than the pre-analysis value is before the peak of the actual value, the temperature of the refrigerant is reduced from the temperature at that time point; If the point in time at which the actual value is determined to have a steeper gradient than the pre-analysis value is after the peak of the actual value, the temperature of the refrigerant is increased from the temperature at that point in time. The pipe cooling system of claim 1 .

5. When the gradient of the performance value at the time point becomes a negative value for the first time, the temperature control unit identifies the peak of the performance value using the performance values ​​up to that point. The pipe cooling system according to claim 4.

6. When the time when the actual value is determined to have a steeper gradient than the pre-analysis value is after the peak of the actual value, the temperature control unit increases the temperature of the refrigerant from the temperature of the refrigerant at the time when a predetermined delay time has elapsed from the time of the peak, or stops control of the temperature of the refrigerant during the delay time. The pipe cooling system according to claim 4.

7. a registration control step of registering analysis temperatures from the start of concrete curing to the end of curing as preliminary analysis values; a supply control step of supplying a refrigerant from a cooling pipe that is pre-placed inside the concrete during curing; an acquisition control process for acquiring, as an actual value, a detected temperature of the concrete from the start of curing using a temperature sensor previously installed in the concrete; a calculation control step of calculating a gradient of the pre-analysis value, which is a change per unit time of the pre-analysis value, at a time point when a predetermined time has elapsed since the start of curing of the concrete, and a gradient of the actual value, which is a change per unit time of the actual value at that time point; a determination control step of comparing the gradient of the calculated actual value with the gradient of the calculated preliminary analysis value to determine whether the actual value has a steeper gradient than the preliminary analysis value; a temperature control step of controlling the temperature of the refrigerant when the actual value has a steeper gradient than the pre-analysis value; A pipe cooling method comprising:

Images