Deterioration diagnosis device for water heat exchanger and deterioration diagnosis method for water heat exchanger

Abstract

According to the deterioration diagnosis device of the water heat exchanger, under the condition that the differential pressure flow rate determined by the differential pressure flow rate determination part is larger than the capacity flow rate determined by the capacity flow rate determination part, a deterioration mode determination part determines that the deterioration mode of the water heat exchanger is a flow path blockage mode of blockage in a water conveying pipeline; when the actual temperature difference determined by the actual temperature difference determination unit is greater than the estimated temperature difference determined by the estimated temperature difference determination unit, it is determined that the deterioration mode of the water heat exchanger is a heat transfer resistance mode in which the heat transfer of the heat transfer unit is resistance.

Description

Technical Field

[0001] The embodiments of the present invention relate to a deterioration diagnosis device for water heat exchangers and a deterioration diagnosis method for water heat exchangers. Background Technology

[0002] For example, Patent Document 1 discloses an abnormal monitoring device for a heat exchanger. In a heat exchanger such as a water heater installed in a power plant's condensate or water supply system, by monitoring both the pressure difference between the water supply pressure at the inlet and outlet of the heat exchanger and the heat exchange performance of the heat exchanger, it can not only determine whether scale is attached, but also determine whether the scale is attached to the inner or outer surface of the heat exchange pipe, or to the water supply flow path outside the heat exchange pipe.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 2675684 Summary of the Invention The technical problem that the invention aims to solve However, while the device in Patent Document 1 can determine that scale has adhered and the location of the scale adhesion, it cannot determine how the heat exchanger deteriorates, i.e., it cannot determine the deterioration mode of the heat exchanger. Especially in water-cooled heat exchangers where heat is exchanged between water and refrigerant, deterioration modes could include those caused by flow path blockage or those caused by scale hindering heat transfer. If it is possible to determine the mode of deterioration, more appropriate countermeasures can be taken.

[0004] Therefore, this embodiment provides a degradation diagnosis device and a degradation diagnosis method, which can determine the mode of degradation of a water heat exchanger that exchanges heat between water flowing in a water supply pipeline and refrigerant flowing in a refrigerant pipeline.

[0005] Solution to the above technical problems The deterioration diagnosis device for a water heat exchanger according to this embodiment includes: a water heat exchanger having a heat transfer section between a water supply pipe for supplying water and a refrigerant pipe for supplying refrigerant, wherein heat exchange occurs between water flowing in the water supply pipe and refrigerant flowing in the refrigerant pipe via the heat transfer section; a differential flow rate determination unit that determines a differential flow rate as a pressure difference flow rate estimated based on the pressure difference between water pressure located upstream of the water heat exchanger and water pressure located downstream of the water heat exchanger; a capacity flow rate determination unit that estimates the flow rate of water flowing in the water supply pipe based on the capacity of the water heat exchanger and determines the estimated flow rate as the capacity flow rate; an actual temperature difference determination unit that determines the actual temperature difference as the temperature difference between the temperature of water flowing in the water supply pipe and the temperature of refrigerant flowing in the refrigerant pipe; and a unit that estimates the actual temperature difference of water flowing in the water supply pipe based on the capacity of the water heat exchanger. The system comprises: a presumed temperature difference determination unit, which determines the presumed temperature difference as the temperature difference between the temperature of the refrigerant flowing in the refrigerant pipeline and the actual temperature difference; and a degradation mode determination unit, which determines the degradation mode of the water heat exchanger based on the pressure difference flow rate determined by the pressure difference flow rate determination unit, the capacity flow rate determined by the capacity flow rate determination unit, the actual temperature difference determined by the actual temperature difference determination unit, and the presumed temperature difference determined by the presumed temperature difference determination unit. The degradation mode determination unit determines that the degradation mode of the water heat exchanger is a flow path blockage mode (blockage in the water supply pipeline) when the pressure difference flow rate determined by the pressure difference flow rate determination unit is greater than the capacity flow rate determined by the capacity flow rate determination unit; and that the degradation mode of the water heat exchanger is a heat transfer obstruction mode (impeded heat transfer in the heat transfer section) when the actual temperature difference determined by the actual temperature difference determination unit is greater than the presumed temperature difference determined by the presumed temperature difference determination unit.

[0006] The deterioration diagnosis method for a water heat exchanger according to this embodiment is a method for diagnosing the deterioration of a water heat exchanger having a heat transfer section between a water supply pipe and a refrigerant supply pipe, wherein heat exchange occurs between water flowing in the water supply pipe and refrigerant flowing in the refrigerant pipe via the heat transfer section. The method includes: a pressure difference flow rate determination process, which determines a flow rate estimated based on the pressure difference between water pressure upstream of the water heat exchanger and water pressure downstream of the water heat exchanger as a pressure difference flow rate; a capacity flow rate determination process, which estimates the flow rate of water flowing in the water supply pipe based on the capacity of the water heat exchanger and determines the estimated flow rate as a capacity flow rate; an actual temperature difference determination process, which determines the temperature difference between the temperature of the water flowing in the water supply pipe and the temperature of the refrigerant flowing in the refrigerant pipe as an actual temperature difference; and an actual temperature difference determination process, which estimates the temperature difference between the temperature of the water flowing in the water supply pipe based on the capacity of the water heat exchanger. The process includes: a presumed temperature difference determination process, which determines the presumed temperature difference based on the temperature difference between the temperature of the refrigerant flowing in the refrigerant pipeline and the actual temperature difference; and a degradation mode determination process, which determines the degradation mode of the water heat exchanger based on the pressure difference flow rate determined by the pressure difference flow rate determination process, the capacity flow rate determined by the capacity flow rate determination process, the actual temperature difference determined by the actual temperature difference determination process, and the presumed temperature difference determined by the presumed temperature difference determination process. In the degradation mode determination process, if the pressure difference flow rate determined by the pressure difference flow rate determination process is greater than the capacity flow rate determined by the capacity flow rate determination process, the degradation mode of the water heat exchanger is determined to be a flow path blockage mode where the water pipeline is blocked. If the actual temperature difference determined by the actual temperature difference determination process is greater than the presumed temperature difference determined by the presumed temperature difference determination process, the degradation mode of the water heat exchanger is determined to be a heat transfer obstruction mode where the heat transfer performance of the heat transfer section is obstructed. Attached Figure Description

[0007] Figure 1 This is a diagram that schematically illustrates an example of the configuration of the cooler system according to the first embodiment.

[0008] Figure 2 This is a block diagram that schematically illustrates an example of the configuration of the control device according to the first embodiment.

[0009] Figure 3 This is a block diagram that schematically illustrates an example of the configuration of the control device according to the second embodiment.

[0010] Figure 4 This is a diagram that schematically illustrates an example of the configuration of the cooler system according to the second embodiment.

[0011] Figure 5This is a diagram that schematically illustrates an example of the configuration of the cooler system according to the third embodiment.

[0012] Figure 6 This is a diagram that schematically illustrates an example of the configuration of the cooler system according to the fourth embodiment. Detailed Implementation

[0013] Hereinafter, several embodiments of the deterioration diagnosis device and method for water heat exchangers will be described with reference to the accompanying drawings. Furthermore, in the various embodiments, substantially the same elements are labeled with the same reference numerals, and their descriptions are omitted.

[0014] (First Embodiment) Figure 1 The illustrated cooler system 100 includes a refrigeration cycle unit 200 and a user-side unit 300. The cooler system 100 can cool or heat an object or space that is the object of temperature control by the cooler system 100 through heat exchange between the refrigerant flowing through the refrigeration cycle unit 200 and the water flowing through the user-side unit 300.

[0015] The refrigeration cycle unit 200 includes a compressor 201, an air heat exchanger 202, a fan 203, an expansion valve 204, a water heat exchanger 205, a liquid receiver 206, a four-way valve 207, and a refrigerant pipeline 208. The compressor 201, air heat exchanger 202, expansion valve 204, water heat exchanger 205, liquid receiver 206, and four-way valve 207 are connected sequentially via the refrigerant pipeline 208.

[0016] The compressor 201 is configured to compress refrigerant. The compressor 201 can, for example, have its operating frequency changed by control using a known inverter. Alternatively, the compressor 201 may be configured to have a fixed operating frequency, meaning its operating frequency cannot be changed.

[0017] The air heat exchanger 202 is, for example, a finned tube type heat exchanger. That is, the air heat exchanger 202 is a heat exchanger constructed by inserting multiple flat fins into the refrigerant pipe 208. A fan 203 is arranged near the air heat exchanger 202. The air heat exchanger 202 performs heat exchange between the air delivered from the fan 203 and the refrigerant passing through the air heat exchanger 202.

[0018] Expansion valve 204 is configured to adjust the valve opening. Expansion valve 204 includes, for example, a valve body with a through-hole, a needle valve retractable relative to the through-hole, and a power source for retracting the needle valve. When the through-hole is blocked by the needle valve, expansion valve 204 blocks the flow of refrigerant in the refrigeration cycle unit 200. At this time, expansion valve 204 is in the closed state, and its opening is at its minimum. When the needle valve is furthest from the through-hole, the flow of refrigerant in the refrigeration cycle unit 200 is maximized. At this time, the opening of expansion valve 204 is at its maximum.

[0019] The water heat exchanger 205 facilitates heat exchange between water flowing in the water supply pipe 301 (which is used for heating or cooling) and refrigerant flowing in the refrigerant pipe 208. The pump 302 pressurizes the water in the water supply pipe 301 to the water heat exchanger 205.

[0020] The water heat exchanger 205 is a so-called plate water heat exchanger. The water heat exchanger 205 has a structure in which multiple stacked heat exchange plates are held together by a pair of cover plates in their stacking direction. At least one cover plate has multiple joints serving as inlets and outlets for water or refrigerant. The water heat exchanger 205 is connected to a water supply pipe 301 for water flow and a refrigerant supply pipe 208 for refrigerant flow, which are alternately separated on the plates by the water flow path and the refrigerant flow path, thereby providing a heat transfer section 205a for heat exchange between water and refrigerant.

[0021] The receiver 206 has a housing made of metal, such as steel. The lower part of the receiver 206 contains liquid refrigerant. The upper part of the receiver 206 contains gaseous refrigerant. The receiver 206 supplies the gaseous refrigerant to the compressor 201.

[0022] The four-way valve 207 switches the refrigeration cycle unit 200 between heating and cooling operation by changing the flow direction of the refrigerant in the refrigerant pipeline 208. In both heating and cooling operation modes, the flow direction of the refrigerant in the refrigerant pipeline 208 is reversed.

[0023] When the refrigeration cycle unit 200 is switched to heating operation mode, the water flowing in the water supply pipe 301 is heated by the water heat exchanger 205. In heating operation mode, the refrigerant flows in the following order: compressor 201, water heat exchanger 205, expansion valve 204, air heat exchanger 202, and liquid receiver 206.

[0024] To explain in more detail, the refrigerant heated by the compressor 201 condenses in the water heat exchanger 205 and exchanges heat with the water in the water supply pipe 301. This heats the water flowing in the water supply pipe 301. At this time, the water heat exchanger 205 functions as a condenser for refrigerant condensation. After exchanging heat with the water in the water heat exchanger 205, the refrigerant is depressurized in the expansion valve 204 and exchanges heat with the air blown by the fan 203 in the air heat exchanger 202. At this time, the air heat exchanger 202 functions as an evaporator for refrigerant evaporation. After exchanging heat with the air in the air heat exchanger 202, the refrigerant returns to the compressor 201 via the receiver 206, is heated again, and then sent to the water heat exchanger 205. Through this refrigerant cycle, the water heat exchanger 205 heats the water flowing in the water supply pipe 301.

[0025] On the other hand, when the refrigeration cycle unit 200 is switched to cooling operation mode, the water flowing in the water supply pipe 301 is cooled by the water heat exchanger 205. In cooling operation mode, the refrigerant flows in the order of compressor 201, air heat exchanger 202, expansion valve 204, water heat exchanger 205, and liquid receiver 206.

[0026] To explain in more detail, the refrigerant heated by the compressor 201 condenses in the air heat exchanger 202 and exchanges heat with the air blown by the fan 203. At this time, the air heat exchanger 202 functions as a condenser for condensing the refrigerant. After exchanging heat with the air in the air heat exchanger 202, the refrigerant is depressurized in the expansion valve 204 and exchanges heat with the water in the water supply pipe 301 in the water heat exchanger 205. This cools the water flowing in the water supply pipe 301. At this time, the water heat exchanger 205 functions as an evaporator for evaporating the refrigerant. After exchanging heat with the air in the water heat exchanger 205, the refrigerant returns to the compressor 201 via the receiver 206, is heated again, and then sent to the air heat exchanger 202. Through this refrigerant cycle, the water heat exchanger 205 cools the water flowing in the water supply pipe 301.

[0027] The portion of the cooler system 100 in the refrigerant line 208 closer to the receiver 206 than the compressor 201 includes a receiver-side refrigerant pressure gauge 221 and a receiver-side refrigerant temperature gauge 231. Furthermore, the portion of the cooler system 100 in the refrigerant line 208 opposite to the receiver 206 than the compressor 201 includes a receiver-side refrigerant pressure gauge 222 and a receiver-side refrigerant temperature gauge 232.

[0028] The portion of the cooler system 100 upstream of the water heat exchanger 205 in the water supply pipe 301 includes an upstream water pressure gauge 321 and an upstream water temperature gauge 331. Furthermore, the portion of the cooler system 100 downstream of the water heat exchanger 205 in the water supply pipe 301 includes a downstream water pressure gauge 322 and a downstream water temperature gauge 332.

[0029] Next, the control device 400 that controls the cooler system 100 will be described in detail. The control device 400 is, for example, a computer, and is capable of controlling the overall operation of the cooler system 100 based on a control program or various setting data. In addition, the control device 400 also functions as a deterioration diagnosis device for the water heat exchanger 205, and is configured to diagnose the deterioration of the water heat exchanger 205.

[0030] The control device 400 is connected to various drive system components such as the compressor 201, fan 203, expansion valve 204, four-way valve 207, and pump 302. Furthermore, the control device 400 is connected to various sensor systems such as the refrigerant pressure gauge 221 on the receiver side, the refrigerant temperature gauge 231 on the receiver side, the refrigerant pressure gauge 222 on the receiver side, the refrigerant temperature gauge 232 on the receiver side, the upstream water pressure gauge 321, the upstream water temperature gauge 331, the downstream water pressure gauge 322, and the downstream water temperature gauge 332.

[0031] like Figure 2 As shown, the control device 400 virtually implements the differential pressure flow rate determination processing unit 401, the capacity flow rate determination processing unit 402, the actual temperature difference determination processing unit 403, the estimated temperature difference determination processing unit 404, the degradation mode determination processing unit 405, and the notification processing unit 406 in software by executing a degradation diagnosis program. Furthermore, the differential pressure flow rate determination processing unit 401, the capacity flow rate determination processing unit 402, the actual temperature difference determination processing unit 403, the estimated temperature difference determination processing unit 404, the degradation mode determination processing unit 405, and the notification processing unit 406 can be implemented in hardware or through a combination of software and hardware.

[0032] The differential pressure flow rate determination processing unit 401 is one example of a differential pressure flow rate determination unit, capable of performing differential pressure flow rate determination processing. This processing estimates and determines the flow rate as the differential pressure flow rate based on the pressure difference between the water pressure detected by the upstream pressure gauge 321 located in the portion of the water supply pipe 301 further upstream of the water heat exchanger 205 and the water pressure detected by the downstream pressure gauge 322 located in the portion of the water supply pipe 301 further downstream of the water heat exchanger 205. In other words, it can be estimated that the greater the pressure difference between the water pressure upstream and downstream of the water heat exchanger 205, the greater the water flow rate; conversely, the smaller the pressure difference, the smaller the water flow rate.

[0033] The capacity flow determination processing unit 402 is an example of a capacity flow determination unit, capable of performing capacity flow determination processing. Capacity flow determination processing is a process that estimates the flow rate of water flowing in the water supply pipe 301 based on the capacity of the water heat exchanger 205, and determines the estimated flow rate as the capacity flow rate.

[0034] The capacity of the water-heat exchanger 205 can be estimated based on the enthalpy change of the refrigerant flowing in the refrigerant pipe 208 or the refrigerant circulation rate within the refrigerant pipe 208. The enthalpy change of the refrigerant flowing in the refrigerant pipe 208 can be calculated based on the pressure of the refrigerant flowing in the refrigerant pipe 208 detected by the refrigerant pressure gauge 221 on the receiver side or the refrigerant pressure gauge 222 on the receiver side, or the temperature of the refrigerant flowing in the refrigerant pipe 208 detected by the refrigerant thermometer 231 on the receiver side or the refrigerant thermometer 232 on the receiver side. The refrigerant circulation rate within the refrigerant pipe 208 can be calculated based on the drive frequency of the compressor 201 or the density of the refrigerant filling the refrigerant pipe 208. The density of the refrigerant filling the refrigerant pipe 208 generally varies primarily depending on the type of refrigerant, but can also be affected by the amount of refrigerant filled or the ambient temperature.

[0035] The water heat exchanger 205 can also estimate the temperature of the water flowing in the water supply pipe 301 with greater accuracy by reflecting the temperature changes of the water flowing in the pipe, as detected by the upstream thermometer 331 or the downstream thermometer 332.

[0036] The actual temperature difference determination processing unit 403 is one example of an actual temperature difference determination unit, capable of performing actual temperature difference determination processing. The actual temperature difference determination processing is the process of determining the actual temperature difference as the temperature difference between the water flowing in the water supply pipe 301 within the water heat exchanger 205 and the refrigerant flowing in the refrigerant pipe 208. That is, the actual temperature difference can be defined as the temperature difference between the water flowing in the water heat exchanger 205 and the refrigerant. Within the water heat exchanger 205, the temperature of the water flowing in the water supply pipe 301 can be detected by an upstream-side water thermometer 331 or a downstream-side water thermometer 332. The temperature of the refrigerant flowing in the refrigerant pipe 208 can be detected by a refrigerant thermometer 231 on the receiver side or a refrigerant thermometer 232 on the receiver side.

[0037] The estimated temperature difference determination processing unit 404 is an example of an estimated temperature difference determination unit, and is capable of performing estimated temperature difference determination processing. The estimated temperature difference determination processing is based on the capability of the water heat exchanger 205 to estimate the temperature difference between the water flowing in the water supply pipe 301 in the water heat exchanger 205 and the refrigerant flowing in the refrigerant pipe 208, and determines the estimated temperature difference as the estimated temperature difference.

[0038] As described above, the capacity of the water heat exchanger 205 can be estimated based on the enthalpy change of the refrigerant flowing in the refrigerant pipe 208 or the amount of refrigerant circulating in the refrigerant pipe 208, and can also be estimated with higher accuracy by reflecting the temperature change of the water flowing in the water supply pipe 301.

[0039] The degradation mode determination processing unit 405 is an example of a degradation mode determination unit, and it is capable of performing degradation mode determination processing. The degradation mode determination processing is based on the differential pressure flow determined by the differential pressure flow determination processing unit 401, the capacity flow determined by the capacity flow determination processing unit 402, the actual temperature difference determined by the actual temperature difference determination processing unit 403, and the estimated temperature difference determined by the estimated temperature difference determination processing unit 404, to determine the degradation mode of the water heat exchanger 205.

[0040] In more detail, if the differential flow rate determined by the differential flow rate determination unit 401 is greater than the capacity flow rate determined by the capacity flow rate determination unit 402 by a predetermined reference amount, the degradation mode determination processing unit 405 determines that the degradation mode of the water heat exchanger 205 is a "flow path blockage mode". A flow path blockage mode refers to a degradation mode in which scale buildup inside the water supply pipe 301 causes blockage. The predetermined reference amount used to determine whether the "flow path blockage mode" has occurred can be appropriately changed and set.

[0041] Furthermore, if the actual temperature difference determined by the actual temperature difference determination unit 403 is greater than the estimated temperature difference determined by the estimated temperature difference determination unit 404 by a predetermined reference amount, the degradation mode determination processing unit 405 determines that the degradation mode of the water heat exchanger 205 is a "heat transfer obstruction mode". A heat transfer obstruction mode refers to a degradation mode in which scale buildup on the heat transfer section 205a causes obstruction of heat transfer in that section. The predetermined reference amount used to determine whether a "heat transfer obstruction mode" has occurred can be appropriately changed and set.

[0042] In the water heat exchanger 205, there may be cases where only the "flow path blockage mode" deterioration occurs, cases where only the "heat transfer obstruction mode" deterioration occurs, and cases where both the "flow path blockage mode" and the "heat transfer obstruction mode" deteriorate simultaneously.

[0043] The notification processing unit 406 is an example of a notification unit, capable of performing notification processing. Notification processing involves notifying the user of the degradation mode determination result determined by the degradation mode determination processing unit 405. Notification processing can be performed, for example, by using a display output device (not shown) provided with the control device 400 to provide visual information, or by using an audio output device (not shown) provided with the control device 400 to provide auditory information, or by using both visual and auditory information. The display output device is, for example, a monitor. The audio output device is, for example, a speaker.

[0044] If the degradation mode determination result of the degradation mode determined by the degradation mode determination processing unit 405 is "flow path blockage mode", the notification processing unit 406 notifies the water heat exchanger 205 that "flow path blockage mode" degradation has occurred. Furthermore, if the degradation mode determination result of the degradation mode determined by the degradation mode determination processing unit 405 is "heat transfer obstruction mode", the notification processing unit 406 notifies the water heat exchanger 205 that "heat transfer obstruction mode" degradation has occurred.

[0045] Furthermore, if the degradation mode determination result by the degradation mode determination processing unit 405 is both "flow path blockage mode" and "heat transfer obstruction mode", the notification processing unit 406 can notify the water heat exchanger 205 that both "flow path blockage mode" and "heat transfer obstruction mode" degradation have occurred, or it can notify only one of the degradation modes. In the case of notifying only one of the degradation modes, for example, the degradation mode of the one with a greater degree of degradation can be selected and notified, or the degradation mode pre-specified by the user can be notified.

[0046] According to the control device 400 of the cooler system 100 illustrated above, it is possible to determine whether the degradation mode of the water heat exchanger 205 is a "flow path blockage mode" or a "heat transfer obstruction mode" based on the relationship between the differential pressure flow determined by the differential pressure flow determination processing unit 401 and the capacity flow determined by the capacity flow determination processing unit 402, and the relationship between the actual temperature difference determined by the actual temperature difference determined by the actual temperature difference determination processing unit 403 and the estimated temperature difference determined by the estimated temperature difference determination processing unit 404. Furthermore, in the water heat exchanger 205, there may be a situation where both the "flow path blockage mode" and the "heat transfer obstruction mode" degradation occur simultaneously. In this case, it is also possible to determine that both degradation modes occur simultaneously. Therefore, regarding the water heat exchanger 205 that exchanges heat between the water flowing in the water supply pipe 301 and the refrigerant flowing in the refrigerant pipe 208, it is possible to determine which mode of degradation has occurred and to take more appropriate countermeasures based on the degradation mode.

[0047] Regarding the two degradation modes, "flow path blockage mode" and "heat transfer impairment mode," both will eventually lead to flow path blockage within the water supply pipe 301. However, in the initial stage, i.e., when flow path blockage begins, the degradation modes differ as follows: In the "flow path blockage mode," the increase in pressure loss of the water flowing within the water supply pipe 301 is more significant, while in the "heat transfer impairment mode," the deterioration of the heat transfer performance of the heat transfer section 205a is more significant.

[0048] Therefore, by comparing the differential pressure flow rate determined by the differential pressure flow rate determination processing unit 401 with the capacity flow rate determined by the capacity flow rate determination processing unit 402, it is possible to determine whether a "flow path blockage mode" has occurred. That is, when scale accumulates in the water supply pipe 301, the pressure loss of the water flowing within it increases. Furthermore, when the pressure loss of the water flowing within the water supply pipe 301 increases, the differential pressure flow rate determined by the differential pressure flow rate determination processing unit 401 is easily affected by the increased pressure loss and thus increases. However, the capacity flow rate determined by the capacity flow rate determination processing unit 402 is based on the capacity of the water heat exchanger 205 and is therefore less affected by the increased pressure loss, making it less prone to change. Therefore, when the differential pressure flow rate determined by the differential pressure flow rate determination processing unit 401 is significantly larger than the capacity flow rate determined by the capacity flow rate determination processing unit 402, it can be determined that the degradation mode of the water heat exchanger 205 is a "flow path blockage mode."

[0049] Furthermore, by comparing the actual temperature difference determined by the actual temperature difference determination processing unit 403 with the estimated temperature difference determined by the estimated temperature difference determination processing unit 404, it is possible to determine whether a "heat transfer obstruction mode" has occurred. That is, when scale adheres to the heat transfer section 205a, its heat transfer performance deteriorates. Moreover, when the heat transfer performance of the heat transfer section 205a deteriorates, the actual temperature difference determined by the actual temperature difference determination processing unit 403 is easily affected by the deterioration in heat transfer performance and becomes larger. However, the estimated temperature difference determined by the estimated temperature difference determination processing unit 404 is an estimated temperature difference based on the capacity of the water heat exchanger 205, and therefore is less affected by the deterioration in heat transfer performance and thus less likely to change. Therefore, when the actual temperature difference determined by the actual temperature difference determination processing unit 403 is much larger than the estimated temperature difference determined by the estimated temperature difference determination processing unit 404, it can be determined that the degradation mode of the water heat exchanger 205 is a "heat transfer obstruction mode."

[0050] As described above, this application discloses an implementation that focuses on the significant differences observed in different degradation modes in the early stages of flow path blockage, thereby enabling determination of the degradation mode of the water heat exchanger 205.

[0051] (Second Implementation) Figure 3The control device 400 illustrated herein is configured to replace the capability flow determination processing unit 402 and instead include an actual flow determination processing unit 407. The control device 400 virtually implements the actual flow determination processing unit 407 in software by executing a degradation diagnostic program. Furthermore, the actual flow determination processing unit 407 can be implemented in hardware or through a combination of software and hardware.

[0052] The actual flow rate determination processing unit 407 is one example of an actual flow rate determination unit, capable of performing actual flow rate determination processing. Actual flow rate determination processing is the process of determining the actual flow rate of water flowing within the water supply pipe 301 as the actual flow rate. The actual flow rate of water flowing within the water supply pipe 301 can be determined by... Figure 4 The flow meter 341 illustrated in the figure is used for detection. In this case, the flow meter 341 is installed in the water supply pipe 301 at a point upstream of the water heat exchanger 205, but it can be installed at any point that can detect the actual flow rate of water flowing in the water supply pipe 301. For example, it can also be installed in the water supply pipe 301 at a point downstream of the water heat exchanger 205, or it can be installed in the water supply pipe 301 within the water heat exchanger 205.

[0053] If the differential flow rate determined by the differential flow rate determination unit 401 is greater than the actual flow rate determined by the actual flow rate determination unit 407 by a predetermined reference amount, the degradation mode determination processing unit 405 determines that the degradation mode of the water heat exchanger 205 is "flow path blockage mode".

[0054] According to the second embodiment, it is also possible to determine in what mode the water heat exchanger 205, which exchanges heat between the water flowing in the water supply pipe 301 and the refrigerant flowing in the refrigerant pipe 208, deteriorates.

[0055] Furthermore, the differential pressure flow determined by the differential pressure flow determination processing unit 401 can be compared with the measured value rather than the estimated value, thereby enabling a more accurate determination of whether a "flow path blockage mode" has occurred.

[0056] Alternatively, in the second embodiment, the control device 400 may simultaneously include a capacity flow rate determination processing unit 402 and an actual flow rate determination processing unit 407, and appropriately select any flow rate value from the capacity flow rate determined by the capacity flow rate determination processing unit 402 and the actual flow rate determined by the actual flow rate determination processing unit 407 to compare with the differential pressure flow rate determined by the differential pressure flow rate determination processing unit 401. Alternatively, the capacity flow rate determined by the capacity flow rate determination processing unit 402 and the actual flow rate determined by the actual flow rate determination processing unit 407 may be determined, for example, by an average value, median value, maximum value, minimum value, etc., and this determined value may be compared with the differential pressure flow rate determined by the differential pressure flow rate determination processing unit 401.

[0057] (Third implementation) Figure 5 The refrigeration system 100 illustrated herein is configured to have multiple (in this case, two) refrigeration cycle units 200 relative to one user-side unit 300. In other words, it is configured to have multiple (in this case, two) refrigerant pipes 208 corresponding to one water supply pipe 301.

[0058] In this configuration example, the degradation mode determination processing unit 405 can determine the degradation mode by using the capability of the water heat exchanger 205 estimated from the relationship between the refrigerant pipe 208 and the water supply pipe 301 on one side, and can also determine the degradation mode by using the capability of the water heat exchanger 205 estimated from the relationship between the refrigerant pipe 208 and the water supply pipe 301 on the other side.

[0059] Furthermore, when a degradation mode is determined based on the capability of the water heat exchanger 205 estimated from the relationship between one refrigerant pipe 208 and the water supply pipe 301, the notification processing unit 406 can notify that degradation has occurred in the relationship with that refrigerant pipe 208. Similarly, when a degradation mode is determined based on the capability of the water heat exchanger 205 estimated from the relationship between the other refrigerant pipe 208 and the water supply pipe 301, the notification processing unit 406 can notify that degradation has occurred in the relationship with that other refrigerant pipe 208. In other words, according to this configuration example, it is possible to determine which of the multiple refrigerant pipes 208 the water heat exchanger 205 has degraded in its relationship with, and further, to determine which of the multiple refrigeration cycle units 200 the water heat exchanger 205 has degraded in its relationship with.

[0060] Furthermore, even if a deterioration mode is determined by estimating the capacity of the water heat exchanger 205 based on the relationship between any one of the multiple refrigerant pipes 208 and the water supply pipe 301, the notification processing unit 406 can also notify the water heat exchanger 205 that deterioration has occurred in its relationship with the overall relationship of the multiple refrigerant pipes 208, including the other refrigerant pipes 208.

[0061] (Fourth implementation) Figure 6The cooler system 100 illustrated herein is configured such that multiple (in this case, two) water heat exchangers 205 are connected in series on a single water supply pipe 301. An intermediate water pressure gauge 323 and an intermediate water temperature gauge 333 are provided between the multiple water heat exchangers 205 on the water supply pipe 301. That is, the configuration example of the fourth embodiment is a configuration with multiple (in this case, two) water heat exchangers connected in series as illustrated in the first embodiment. According to this configuration example, the degradation mode determination processing unit 405 can determine the degradation mode for each water heat exchanger 205 separately.

[0062] Furthermore, if a degradation mode is determined for one of the water heat exchangers 205, the notification processing unit 406 can notify that degradation has occurred on that water heat exchanger 205. Similarly, if a degradation mode is determined for the other water heat exchanger 205, the notification processing unit 406 can notify that degradation has occurred on that other water heat exchanger 205. In other words, according to this configuration example, it is possible to determine which water heat exchanger 205 has degraded.

[0063] Furthermore, even if a degradation mode is determined for any one of the multiple water heat exchangers 205, the notification processing unit 406 can notify that the entire group of multiple water heat exchangers 205, including the other water heat exchangers 205, has degraded.

[0064] (Other implementation methods) Furthermore, this embodiment is not limited to the above-described embodiments, and various modifications or extensions can be made without departing from its spirit. For example, it may be an embodiment that combines at least two or more suitable embodiments described above. In addition, the differential pressure flow rate, capacity flow rate, actual temperature difference, and estimated temperature difference are not limited to the determination methods described above, and various known methods can also be used to determine them.

[0065] The foregoing has described several embodiments of the present invention, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments or their variations are included within the scope or spirit of the invention, and also within the scope of the invention as described in the claims and its equivalents.

[0066] Explanation of reference numerals in the attached figures 205 Water Heat Exchanger 205a Heat Transfer Section 208 Refrigerant Pipe 301 Water Supply Pipeline 400 Control device (deterioration diagnosis device for water heat exchangers) 401 Differential Pressure Flow Rate Determination and Processing Department (Differential Pressure Flow Rate Determination Department) 402 Capacity and Flow Determination Processing Unit (Capacity and Flow Determination Unit) 403 Actual Temperature Difference Determination and Processing Department (Actual Temperature Difference Determination Department) 404 Estimated Temperature Difference Determination Processing Department (Estimated Temperature Difference Determination Department) 405 Degradation Mode Determination and Processing Department (Degradation Mode Determination Department) 407 Actual Flow Determination Processing Unit (Actual Flow Determination Unit).

Claims

1. A deterioration diagnosis device of a water heat exchanger, characterized by, Possessing: a water heat exchanger that performs heat exchange between water flowing in a water supply conduit and refrigerant flowing in a refrigerant conduit via a heat transfer portion provided between the water supply conduit and the refrigerant conduit; a pressure difference flow rate determining portion that determines a flow rate that is estimated from a pressure difference between a pressure of water located on an upstream side of the water heat exchanger in the water supply conduit and a pressure of water located on a downstream side of the water heat exchanger in the water supply conduit as a pressure difference flow rate; a capacity flow rate determining portion that estimates a flow rate of water flowing in the water supply conduit based on a capacity of the water heat exchanger and determines the estimated flow rate as a capacity flow rate; an actual temperature difference determining portion that determines a temperature difference between a temperature of water flowing in the water supply conduit and a temperature of refrigerant flowing in the refrigerant conduit as an actual temperature difference; an estimated temperature difference determining portion that estimates a temperature difference between a temperature of water flowing in the water supply conduit and a temperature of refrigerant flowing in the refrigerant conduit based on a capacity of the water heat exchanger and determines the estimated temperature difference as an estimated temperature difference; and a deterioration mode determining portion that determines a deterioration mode of the water heat exchanger based on the pressure difference flow rate determined by the pressure difference flow rate determining portion, the capacity flow rate determined by the capacity flow rate determining portion, the actual temperature difference determined by the actual temperature difference determining portion, and the estimated temperature difference determined by the estimated temperature difference determining portion, the deterioration mode determining portion, determines that the deterioration mode of the water heat exchanger is a flow path clogging mode in which the water supply conduit is clogged when the pressure difference flow rate determined by the pressure difference flow rate determining portion is greater than the capacity flow rate determined by the capacity flow rate determining portion, determines that the deterioration mode of the water heat exchanger is a heat transfer resistance mode in which heat transfer of the heat transfer portion is obstructed when the actual temperature difference determined by the actual temperature difference determining portion is greater than the estimated temperature difference determined by the estimated temperature difference determining portion. Possessing:

2. The deterioration diagnosis device of a water heat exchanger according to claim 1, characterized in that, an actual flow rate determining portion that determines a flow rate of water actually flowing in the water supply conduit as an actual flow rate, the deterioration mode determining portion, determines that the deterioration mode of the water heat exchanger is the flow path clogging mode when the pressure difference flow rate determined by the pressure difference flow rate determining portion is greater than the actual flow rate determined by the actual flow rate determining portion. Including:

3. A method for diagnosing the deterioration of a water heat exchanger, comprising a heat transfer section between a water supply pipe and a refrigerant supply pipe, wherein heat exchange occurs between water flowing in the water supply pipe and refrigerant flowing in the refrigerant pipe via the heat transfer section, characterized in that... a pressure difference flow rate determining process that determines a flow rate that is estimated from a pressure difference between a pressure of water located on an upstream side of a water heat exchanger in a water supply conduit and a pressure of water located on a downstream side of the water heat exchanger in the water supply conduit as a pressure difference flow rate; a capacity flow rate determining process that estimates a flow rate of water flowing in the water supply conduit based on a capacity of the water heat exchanger and determines the estimated flow rate as a capacity flow rate; an actual temperature difference determining process that determines a temperature difference between a temperature of water flowing in the water supply conduit and a temperature of refrigerant flowing in a refrigerant conduit as an actual temperature difference; ​ estimating a temperature difference between the temperature of the water flowing in the water pipeline and the temperature of the refrigerant flowing in the refrigerant pipeline based on the capacity of the water heat exchanger, and determining the estimated temperature difference as an estimated temperature difference; and determining a deterioration mode of the water heat exchanger based on the pressure difference flow rate determined by the pressure difference flow rate determining process, the capacity flow rate determined by the capacity flow rate determining process, the actual temperature difference determined by the actual temperature difference determining process, and the estimated temperature difference determined by the estimated temperature difference determining process, in the deterioration mode determining process, in a case where the pressure difference flow rate determined by the pressure difference flow rate determining process is greater than the capacity flow rate determined by the capacity flow rate determining process, determining the deterioration mode of the water heat exchanger as a flow path clogging mode in which a flow path in the water pipeline is clogged, in a case where the actual temperature difference determined by the actual temperature difference determining process is greater than the estimated temperature difference determined by the estimated temperature difference determining process, determining the deterioration mode of the water heat exchanger as a heat transfer resistance mode in which heat transfer resistance of the heat transfer portion is increased.

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