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

Abstract

To provide a deterioration diagnostic device and a deterioration diagnostic method capable of determining a pattern of deterioration of a water heater exchanger that performs heat exchange between water flowing in water piping and a refrigerant flowing in refrigerant piping.SOLUTION: In a deterioration diagnostic device for a water heat exchanger, a deterioration pattern determination section determines that a deterioration pattern of a water heat exchanger is a flow passage closed pattern indicating that inside of water piping is closed when a differential pressure flow rate specified by a differential pressure flow rate specification section is larger than a capacity flow rate specified by a capacity flow rate specification section, and determines that the deterioration pattern of the water heat exchanger is a heat transfer performance inhibited pattern indicating that heat transfer performance of a heat transfer section is inhibited when an actual temperature difference specified by an actual temperature difference specification section is larger than an estimation temperature difference specified by an estimation temperature difference specification section.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a deterioration diagnosis device and a deterioration diagnosis method for a water heat exchanger. [Background technology]

[0002] For example, Patent Document 1 discloses an abnormality monitoring device for a heat exchanger that monitors both the differential pressure of the feedwater pressure at the inlet and outlet of a heat exchanger and the heat exchange performance of the heat exchanger in a heat exchanger such as a feedwater heater installed in the condensate or feedwater system of a power plant, thereby making it possible to determine not only whether scale has adhered, but also whether the scale has adhered to the inner or outer surface of the heat exchange tube, or to a part of the feedwater flow path other than the heat exchange tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2675684 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the device of Patent Document 1 can identify the presence of scale and the location of the scale, it cannot determine how the heat exchanger has deteriorated, that is, the deterioration pattern of the heat exchanger. In particular, in a water heat exchanger that exchanges heat between water and a refrigerant, possible deterioration patterns include deterioration due to blockage of the flow path and deterioration due to scale that inhibits heat transfer, and if it is possible to determine the deterioration pattern, more appropriate measures can be taken.

[0005] Therefore, this embodiment provides a deterioration diagnosis device and a deterioration diagnosis method that are capable of determining the pattern of deterioration of a water heat exchanger that exchanges heat between water flowing in a water piping and a refrigerant flowing in a refrigerant piping. [Means for solving the problem]

[0006] The deterioration diagnosis device for a water heat exchanger according to the present embodiment includes a water heat exchanger having a heat transfer unit between a water pipe through which water flows and a refrigerant pipe through which a refrigerant flows, and performing heat exchange between the water flowing in the water pipe and the refrigerant flowing in the refrigerant pipe via the heat transfer unit; a differential pressure flow rate specifying unit that specifies a flow rate estimated from a pressure difference between a water pressure in the water pipe upstream of the water heat exchanger and a water pressure in the water pipe downstream of the water heat exchanger as a differential pressure flow rate; a capacity flow rate specifying unit that estimates the flow rate of water flowing in the water pipe based on the capacity of the water heat exchanger and specifies the estimated flow rate as a capacity flow rate; an actual temperature difference specifying unit that specifies a temperature difference between the temperature of the water flowing in the water pipe and the temperature of the refrigerant flowing in the refrigerant pipe as an actual temperature difference; and a temperature difference specifying unit that estimates the temperature difference between the temperature of the water flowing in the water pipe and the temperature of the refrigerant flowing in the refrigerant pipe based on the capacity of the water heat exchanger and specifies the estimated temperature difference as a capacity flow rate. the deterioration pattern determination unit determines a deterioration pattern of the water heat exchanger based on the differential pressure flow rate determined by the differential pressure 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 estimated temperature difference determined by the estimated temperature difference determination unit, and if the differential pressure flow rate determined by the differential pressure flow rate determination unit is greater than the capacity flow rate determined by the capacity flow rate determination unit, the deterioration pattern of the water heat exchanger is a flow path blockage pattern in which the water piping is blocked, and if 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, the deterioration pattern of the water heat exchanger is a heat transfer inhibition pattern in which the heat transfer property of the heat transfer section is inhibited.

[0007] The deterioration diagnosis method for a water heat exchanger according to the present embodiment is a method for diagnosing deterioration of a water heat exchanger that includes a heat transfer unit between a water pipe through which water flows and a refrigerant pipe through which a refrigerant flows, and that performs heat exchange between the water flowing in the water pipe and the refrigerant flowing in the refrigerant pipe via the heat transfer unit, and includes the following steps: a differential pressure flow rate determination process for determining a flow rate estimated from a pressure difference between a water pressure in the water pipe upstream of the water heat exchanger and a water pressure in the water pipe downstream of the water heat exchanger as a differential pressure flow rate; a capacity flow rate determination process for estimating a flow rate of water flowing in the water pipe based on a capacity of the water heat exchanger and determining the estimated flow rate as a capacity flow rate; an actual temperature difference determination process for determining a temperature difference between a temperature of the water flowing in the water pipe and a temperature of the refrigerant flowing in the refrigerant pipe as an actual temperature difference; and a temperature difference determination process for estimating a temperature difference between the temperature of the water flowing in the water pipe and the temperature of the refrigerant flowing in the refrigerant pipe based on a capacity of the water heat exchanger and determining the estimated temperature difference as a capacity flow rate. as an estimated temperature difference; and a deterioration pattern determination process that determines a deterioration pattern of the water heat exchanger based on the differential pressure flow rate identified by the differential pressure flow rate identification process, the capacity flow rate identified by the capacity flow rate identification process, the actual temperature difference identified by the actual temperature difference identification process, and the estimated temperature difference identified by the estimated temperature difference identification process. In the deterioration pattern determination process, if the differential pressure flow rate identified by the differential pressure flow rate identification process is larger than the capacity flow rate identified by the capacity flow rate identification process, it is determined that the deterioration pattern of the water heat exchanger is a flow path blockage pattern in which the water piping is blocked, and if the actual temperature difference identified by the actual temperature difference identification process is larger than the estimated temperature difference identified by the estimated temperature difference identification process, it is determined that the deterioration pattern of the water heat exchanger is a heat transfer inhibition pattern in which the heat transfer property of the heat transfer section is inhibited. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a chiller system according to a first embodiment. [Diagram 2] FIG. 1 is a block diagram showing an example of the configuration of a control device according to a first embodiment; [Diagram 3]FIG. 11 is a block diagram showing an example of the configuration of a control device according to a second embodiment. [Figure 4] FIG. 1 is a diagram illustrating an example of the configuration of a chiller system according to a second embodiment. [Diagram 5] FIG. 13 is a diagram illustrating an example of the configuration of a chiller system according to a third embodiment. [Figure 6] FIG. 13 is a diagram illustrating an example of the configuration of a chiller system according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a number of embodiments of a deterioration diagnosis device and a deterioration diagnosis method for a water heat exchanger will be described with reference to the drawings. Note that, in the number of embodiments, substantially the same elements are given the same reference numerals, and the description thereof will be omitted.

[0010] (First embodiment) 1 includes a refrigeration cycle unit 200 and a user-side unit 300. The chiller system 100 performs heat exchange between a refrigerant flowing through the refrigeration cycle unit 200 and water flowing through the user-side unit 300, thereby making it possible to cool or heat an object or space that is the target of temperature control by the chiller system 100.

[0011] 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, an accumulator 206, a four-way valve 207, and a refrigerant piping 208. The compressor 201, the air heat exchanger 202, the expansion valve 204, the water heat exchanger 205, the accumulator 206, and the four-way valve 207 are connected in sequence by the refrigerant piping 208.

[0012] The compressor 201 is configured to be capable of compressing a refrigerant. The compressor 201 is capable of changing the operation frequency by, for example, known inverter control. The compressor 201 may be configured such that the operation frequency cannot be changed, that is, the operation frequency is fixed.

[0013] The air heat exchanger 202 is, for example, a fin-and-tube type heat exchanger. That is, the air heat exchanger 202 is a heat exchanger having a configuration in which refrigerant piping 208 is inserted into a plurality of flat plate-shaped fins. A fan 203 is disposed near the air heat exchanger 202. The air heat exchanger 202 exchanges heat between the air sent from the fan 203 and the refrigerant passing through the air heat exchanger 202.

[0014] The expansion valve 204 is configured to be capable of adjusting the valve opening degree. The expansion valve 204 includes, for example, a valve body having a through hole, a needle that can advance and retreat with respect to the through hole, and a power source for advancing and retreating the needle. When the through hole is blocked by the needle, the expansion valve 204 blocks the flow of refrigerant in the refrigeration cycle unit 200. At this time, the expansion valve 204 is in a closed state, and the opening degree of the expansion valve 204 is the smallest. When the needle is farthest from the through hole, the amount of refrigerant flowing in the refrigeration cycle unit 200 is maximized. At this time, the opening degree of the expansion valve 204 is the largest.

[0015] The water heat exchanger 205 exchanges heat between the water flowing in the water pipe 301 to be heated or cooled and the refrigerant flowing in the refrigerant pipe 208. The pump 302 pumps the water in the water pipe 301 toward the water heat exchanger 205.

[0016] The water heat exchanger 205 is a so-called plate-type water heat exchanger. The water heat exchanger 205 has a configuration in which a plurality of stacked heat exchange plates are sandwiched between a pair of cover plates in the stacking direction. At least one of the cover plates has a plurality of joints that function as inlets and outlets for water and refrigerant. The water heat exchanger 205 has a heat transfer section 205a in which water piping 301 through which water flows and refrigerant piping 208 through which refrigerant flows are connected, and the water flow path and the refrigerant flow path are alternately partitioned by plates, whereby the water and the refrigerant exchange heat.

[0017] The accumulator 206 has a case made of a metal such as steel. A liquid-phase refrigerant is accommodated in a lower part of the accumulator 206. A gas-phase refrigerant is accommodated in an upper part of the accumulator 206. The accumulator 206 supplies the gas-phase refrigerant to the compressor 201.

[0018] The four-way valve 207 switches the refrigeration cycle unit 200 between a heating operation state and a cooling operation state by switching the direction in which the refrigerant flows in the refrigerant pipe 208. In the heating operation state and the cooling operation state, the direction in which the refrigerant flows in the refrigerant pipe 208 is switched to the opposite direction.

[0019] When the refrigeration cycle unit 200 is switched to a heating operation state, the water flowing in the water piping 301 is heated by the water heat exchanger 205. In the heating operation state, the refrigerant flows through the compressor 201, the water heat exchanger 205, the expansion valve 204, the air heat exchanger 202, and the accumulator 206 in this order.

[0020] More specifically, the refrigerant heated to a high temperature by the compressor 201 is condensed in the water heat exchanger 205 and exchanges heat with the water in the water pipe 301. As a result, the water flowing through the water pipe 301 is heated. At this time, the water heat exchanger 205 functions as a condenser that condenses the refrigerant. The refrigerant that has exchanged heat with the water in the water heat exchanger 205 is decompressed in the expansion valve 204, and further 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 that evaporates the refrigerant. The refrigerant that has exchanged heat with the air in the air heat exchanger 202 is returned to the compressor 201 via the accumulator 206, heated to a high temperature again, and sent to the water heat exchanger 205. By circulating the refrigerant in this way, the water heat exchanger 205 heats the water flowing through the water pipe 301.

[0021] On the other hand, when the refrigeration cycle unit 200 is switched to a cooling operation state, the water flowing in the water piping 301 is cooled by the water heat exchanger 205. In the cooling operation state, the refrigerant flows through the compressor 201, the air heat exchanger 202, the expansion valve 204, the water heat exchanger 205, and the accumulator 206 in this order.

[0022] More specifically, the refrigerant heated to a high temperature by the compressor 201 is condensed 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 that condenses the refrigerant. The refrigerant that has exchanged heat with the air in the air heat exchanger 202 is decompressed in the expansion valve 204, and further exchanges heat with the water in the water pipe 301 in the water heat exchanger 205. This cools the water flowing in the water pipe 301. At this time, the water heat exchanger 205 functions as an evaporator that evaporates the refrigerant. The refrigerant that has exchanged heat with the air in the water heat exchanger 205 is returned to the compressor 201 via the accumulator 206, heated to a high temperature again, and sent to the air heat exchanger 202. By circulating the refrigerant in this way, the water heat exchanger 205 cools the water flowing in the water pipe 301.

[0023] Chiller system 100 is provided with an accumulator-side refrigerant pressure gauge 221 and an accumulator-side refrigerant thermometer 231 in a portion of refrigerant piping 208 that is closer to accumulator 206 than compressor 201. Chiller system 100 also is provided with a counter-accumulator-side refrigerant pressure gauge 222 and a counter-accumulator-side refrigerant thermometer 232 in a portion of refrigerant piping 208 that is closer to the accumulator 206 than compressor 201.

[0024] Chiller system 100 is provided with an upstream water pressure gauge 321 and an upstream water temperature gauge 331 in a portion of water piping 301 upstream of water heat exchanger 205. Chiller system 100 also is provided with a downstream water pressure gauge 322 and a downstream water temperature gauge 332 in a portion of water piping 301 downstream of water heat exchanger 205.

[0025] Next, a detailed description will be given of the control device 400 that controls the chiller system 100. The control device 400 is configured mainly by a computer, for example, and can control the overall operation of the chiller system 100 based on a control program, various setting data, etc. The control device 400 also functions as an example of a deterioration diagnosis device for the water heat exchanger 205, and is configured to be able to diagnose deterioration of the water heat exchanger 205.

[0026] The control device 400 is connected to various drive system components such as the above-mentioned compressor 201, fan 203, expansion valve 204, four-way valve 207, pump 302, etc. In addition, the control device 50 is connected to various sensor system components such as the above-mentioned accumulator side refrigerant pressure gauge 221, accumulator side refrigerant thermometer 231, anti-accumulator side refrigerant pressure gauge 222, anti-accumulator side refrigerant thermometer 232, upstream side water pressure gauge 321, upstream side water temperature gauge 331, downstream side water pressure gauge 322, downstream side water temperature gauge 332, etc.

[0027] 2, the control device 400 executes a deterioration diagnosis program to virtually realize a differential pressure flow rate identification processing unit 401, a capacity flow rate identification processing unit 402, an actual temperature difference identification processing unit 403, an estimated temperature difference identification processing unit 404, a deterioration pattern determination processing unit 405, and an alarm processing unit 406 by using software. Note that the differential pressure flow rate identification processing unit 401, the capacity flow rate identification processing unit 402, the actual temperature difference identification processing unit 403, the estimated temperature difference identification processing unit 404, the deterioration pattern determination processing unit 405, and the alarm processing unit 406 may be realized by using hardware or a combination of software and hardware.

[0028] The differential pressure flow rate identifying process unit 401 is an example of a differential pressure flow rate identifying unit, and is capable of executing a differential pressure flow rate identifying process. The differential pressure flow rate identifying process is a process for identifying a flow rate estimated from a pressure difference between the water pressure detected by the upstream water pressure gauge 321 in the portion of the water piping 301 upstream of the water heat exchanger 205 and the water pressure detected by the downstream water pressure gauge 322 in the portion of the water piping 301 downstream of the water heat exchanger 205 as a differential pressure flow rate. That is, the larger the pressure difference between the water pressure upstream of the water heat exchanger 205 and the water pressure downstream of the water heat exchanger 205, the larger the water flow rate can be estimated to be, and conversely, the smaller the pressure difference, the smaller the water flow rate can be estimated to be.

[0029] The capacity flow rate determination processing unit 402 is an example of a capacity flow rate determination unit, and is capable of executing a capacity flow rate determination process. The capacity flow rate determination process is a process of estimating the flow rate of water flowing through the water pipe 301 based on the capacity of the water heat exchanger 205, and determining the estimated flow rate as the capacity flow rate.

[0030] The capacity of the water heat exchanger 205 can be estimated based on the enthalpy change of the refrigerant flowing through the refrigerant pipe 208, the amount of refrigerant circulating through the refrigerant pipe 208, and the like. The enthalpy change of the refrigerant flowing through the refrigerant pipe 208 can be calculated based on the pressure of the refrigerant flowing through the refrigerant pipe 208 detected by the accumulator side refrigerant pressure gauge 221 and the counter-accumulator side refrigerant pressure gauge 222, the temperature of the refrigerant flowing through the refrigerant pipe 208 detected by the accumulator side refrigerant thermometer 231 and the counter-accumulator side refrigerant thermometer 232, and the like. The amount of refrigerant circulating through the refrigerant pipe 208 can be calculated based on the drive frequency of the compressor 201, the density of the refrigerant filled in the refrigerant pipe 208, and the like. The density of the refrigerant filled in the refrigerant pipe 208 differs mainly depending on the type of refrigerant, but may vary depending on the amount of refrigerant filled, the ambient temperature, and the like.

[0031] The capacity of the water heat exchanger 205 can be estimated more accurately by further reflecting changes in the temperature of the water flowing through the water pipe 301 detected by the upstream water thermometer 331 and the downstream water thermometer 332.

[0032] The actual temperature difference identification processing unit 403 is an example of an actual temperature difference identification unit, and is capable of executing an actual temperature difference identification process. The actual temperature difference identification process is a process for identifying the temperature difference between the temperature of the water flowing in the water pipe 301 in the water heat exchanger 205 and the temperature of the refrigerant flowing in the refrigerant pipe 208 as an actual temperature difference. 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. The temperature of the water flowing in the water pipe 301 in the water heat exchanger 205 can be detected by the upstream water thermometer 331 and the downstream water thermometer 332. The temperature of the refrigerant flowing in the refrigerant pipe 208 can be detected by the accumulator side refrigerant thermometer 231 and the anti-accumulator side refrigerant thermometer 232.

[0033] The estimated temperature difference identification processing unit 404 is an example of an estimated temperature difference identification unit, and is capable of executing an estimated temperature difference identification process. The estimated temperature difference identification process is a process of estimating a temperature difference between the temperature of the water flowing in the water pipe 301 in the water heat exchanger 205 and the temperature of the refrigerant flowing in the refrigerant pipe 208 based on the capacity of the water heat exchanger 205, and identifying the estimated temperature difference as an estimated temperature difference.

[0034] As described above, the capacity of the water heat exchanger 205 can be estimated based on the enthalpy change of the refrigerant flowing through the refrigerant piping 208 and the amount of refrigerant circulating through the refrigerant piping 208, and can be estimated more accurately by also reflecting the change in temperature of the water flowing through the water piping 301.

[0035] The deterioration pattern determination processing unit 405 is an example of a deterioration pattern determination unit, and is capable of executing a deterioration pattern determination process. The deterioration pattern determination process is a process for determining a deterioration pattern of the water heat exchanger 205 based on the differential pressure flow rate identified by the differential pressure flow rate identification processing unit 401, the capacity flow rate identified by the capacity flow rate identification processing unit 402, the actual temperature difference identified by the actual temperature difference identification processing unit 403, and the estimated temperature difference identified by the estimated temperature difference identification processing unit 404.

[0036] More specifically, when the differential pressure flow rate identified by the differential pressure flow rate identifying processing processing processing 401 is greater than the capacity flow rate identified by the capacity flow rate identifying processing processing 402 by a predetermined reference amount or more, the deterioration pattern determination processing processing processing 405 determines that the deterioration pattern of the water heat exchanger 205 is a "flow path blockage pattern". The flow path blockage pattern is a deterioration pattern in which scale adheres to the inside of the water pipe 301, causing blockage inside the water pipe 301. The predetermined reference amount for determining whether or not the "flow path blockage pattern" has occurred can be changed and set as appropriate.

[0037] Furthermore, when the actual temperature difference identified by the actual temperature difference identification processing processing processing 403 is greater than the estimated temperature difference identified by the estimated temperature difference identification processing processing processing 404 by a predetermined reference amount or more, the deterioration pattern determination processing processing processing 405 determines that the deterioration pattern of the water heat exchanger 205 is a "heat conductivity hindering pattern". The heat conductivity hindering pattern is a deterioration pattern in which scale adheres to the heat transfer section 205a and the heat conductivity of the heat transfer section 205a is hindered. The predetermined reference amount for determining whether or not a "heat conductivity hindering pattern" has occurred can be changed and set as appropriate.

[0038] In the water heat exchanger 205, there may be cases where only the "flow path blockage pattern" deterioration has occurred, cases where only the "heat conductivity inhibition pattern" deterioration has occurred, or cases where both the "flow path blockage pattern" and the "heat conductivity inhibition pattern" deterioration have occurred simultaneously.

[0039] The notification processing unit 406 is an example of a notification unit, and is capable of executing notification processing. The notification processing is processing for notifying the result of the deterioration pattern determination processing unit 405. The notification processing may be, for example, a visual notification via a display output device (not shown) included in the control device 400, an auditory notification via a sound output device (not shown) included in the control device 400, or both visual and auditory information. The display output device is, for example, a display, etc. The sound output device is, for example, a speaker, etc.

[0040] When the deterioration pattern determination processing unit 405 determines that the deterioration pattern is a "flow path blockage pattern", the notification processing unit 406 notifies that deterioration in the "flow path blockage pattern" has occurred in the water heat exchanger 205. When the deterioration pattern determination processing unit 405 determines that the deterioration pattern is a "thermal conductivity inhibition pattern", the notification processing unit 406 notifies that deterioration in the "thermal conductivity inhibition pattern" has occurred in the water heat exchanger 205.

[0041] Furthermore, when the deterioration pattern determination processing unit 405 determines that the deterioration pattern is both the "flow path blockage pattern" and the "thermal conductivity inhibition pattern," the notification processing unit 406 may notify that deterioration of the "flow path blockage pattern" and deterioration of the "thermal conductivity inhibition pattern" have occurred in the water heat exchanger 205, or may notify only one of the deterioration patterns. When notifying only one of the deterioration patterns, for example, a deterioration pattern with a greater degree of deterioration may be selected and notified, or a deterioration pattern designated in advance by the user may be notified.

[0042] According to the control device 400 of the chiller system 100 exemplified above, it is possible to determine whether the deterioration pattern of the water heat exchanger 205 is a "pathway blockage pattern" or a "thermal conductivity inhibition pattern" based on the magnitude relationship between the differential pressure flow rate determined by the differential pressure flow rate determination processing unit 401 and the capacity flow rate determined by the capacity flow rate determination processing unit 402, and the magnitude relationship between 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. In addition, in the water heat exchanger 205, there are cases where deterioration in both the "pathway blockage pattern" and the "thermal conductivity inhibition pattern" occurs simultaneously, and in such cases, it is possible to determine that both the deterioration patterns of the "pathway blockage pattern" and the "thermal conductivity inhibition pattern" have occurred simultaneously. As a result, it is possible to determine the type of deterioration in the water heat exchanger 205 that exchanges heat between the water flowing in the water pipe 301 and the refrigerant flowing in the refrigerant pipe 208, and to take more appropriate measures according to the deterioration pattern that has occurred.

[0043] In both of the two types of deterioration patterns, the "flow path clogging pattern" and the "heat conductivity inhibition pattern," the flow path in water pipe 301 eventually becomes blocked. However, in the early stages, that is, when the flow path begins to become blocked, the following differences are observed between the respective deterioration patterns. That is, in the "flow path clogging pattern," there is a significant increase in pressure loss of the water flowing in water pipe 301, while in the "heat conductivity inhibition pattern," there is a significant deterioration in the heat transfer performance of heat transfer section 205a.

[0044] Therefore, by comparing the magnitude relationship between the differential pressure flow rate specified by the differential pressure flow rate specification processing unit 401 and the capacity flow rate specified by the capacity flow rate specification processing unit 402, it is possible to determine whether or not a "flow path clogging pattern" has occurred. That is, when scale is clogged in the water pipe 301, the pressure loss of the water flowing in the water pipe 301 increases. When the pressure loss of the water flowing in the water pipe 301 increases, the differential pressure flow rate specified by the differential pressure flow rate specification processing unit 401 is likely to increase due to the increase in pressure loss, but the capacity flow rate specified by the capacity flow rate specification processing unit 402 is based on the capacity of the water heat exchanger 205 and is therefore less susceptible to the increase in pressure loss and therefore is less likely to change. Therefore, when the differential pressure flow rate specified by the differential pressure flow rate specification processing unit 401 is sufficiently larger than the capacity flow rate specified by the capacity flow rate specification processing unit 402, it is possible to determine that the deterioration pattern of the water heat exchanger 205 is a "flow path clogging pattern".

[0045] Moreover, by comparing the magnitude relationship between the actual temperature difference specified by the actual temperature difference determination processing unit 403 and the estimated temperature difference specified by the estimated temperature difference determination processing unit 404, it is possible to determine whether or not a "heat transfer inhibition pattern" has occurred. That is, when scale adheres to the heat transfer unit 205a, the heat transfer performance of the heat transfer unit 205a deteriorates. When the heat transfer performance of the heat transfer unit 205a deteriorates, the actual temperature difference specified by the actual temperature difference determination processing unit 403 is likely to become large due to the influence of the deterioration of the heat transfer performance, but the estimated temperature difference specified by the estimated temperature difference determination processing unit 404 is based on the capacity of the water heat exchanger 205 and is therefore less susceptible to the influence of the deterioration of the heat transfer performance, and therefore is less likely to change. Therefore, when the actual temperature difference specified by the actual temperature difference determination processing unit 403 is sufficiently larger than the estimated temperature difference specified by the estimated temperature difference determination processing unit 404, it is possible to determine that the deterioration pattern of the water heat exchanger 205 is a "heat transfer inhibition pattern".

[0046] As described above, the present application discloses an embodiment that makes it possible to determine the pattern in which the water heat exchanger 205 is deteriorating, by focusing on the significant differences in each deterioration pattern observed in the early stages of flow path blockage.

[0047] Second embodiment 3 is configured to include an actual flow rate identification processing unit 407 instead of the capacity flow rate identification processing unit 402. The control device 400 executes a degradation diagnosis program to virtually realize the actual flow rate identification processing unit 407 by software. Note that the actual flow rate identification processing unit 407 may be realized by hardware, or may be realized by a combination of software and hardware.

[0048] The actual flow rate identification processing unit 407 is an example of an actual flow rate identification unit, and is capable of executing an actual flow rate identification process. The actual flow rate identification process is a process for identifying the flow rate of water actually flowing in the water pipe 301 as the actual flow rate. The flow rate of water actually flowing in the water pipe 301 can be detected by a flow meter 341 illustrated in FIG. 4. In this case, the flow meter 341 is provided in a portion of the water pipe 301 that is upstream of the water heat exchanger 205, but as long as the portion is capable of detecting the flow rate of water actually flowing in the water pipe 301, it may be provided in, for example, a portion of the water pipe 301 that is downstream of the water heat exchanger 205, or in a portion of the water pipe 301 within the water heat exchanger 205.

[0049] If the differential pressure flow rate identified by the differential pressure flow rate identification processing unit 401 is greater than a predetermined reference amount or more than the actual flow rate identified by the actual flow rate identification processing unit 407, the deterioration pattern determination processing unit 405 determines that the deterioration pattern of the water heat exchanger 205 is a ``flow path blockage pattern.''

[0050] According to the second embodiment as well, it is possible to determine the pattern of deterioration of the water heat exchanger 205 that exchanges heat between the water flowing in the water pipe 301 and the refrigerant flowing in the refrigerant pipe 208.

[0051] In addition, the differential pressure flow rate identified by the differential pressure flow rate identification processing unit 401 can be compared with an actual measured value rather than an estimated value, making it possible to more accurately determine whether or not a "flow path blockage pattern" has occurred.

[0052] In the second embodiment, the control device 400 may include an actual flow rate determining processing unit 407 together with the capacity flow rate determining processing unit 402, and may appropriately select any one of the capacity flow rate determined by the capacity flow rate determining processing unit 402 and the actual flow rate determined by the actual flow rate determining processing unit 407 to compare with the differential pressure flow rate determined by the differential pressure flow rate determining processing unit 401. Alternatively, for the capacity flow rate determined by the capacity flow rate determining processing unit 402 and the actual flow rate determined by the actual flow rate determining processing unit 407, for example, an average value, a median value, a maximum value, a minimum value, etc. may be determined, and the determined value may be compared with the differential pressure flow rate determined by the differential pressure flow rate determining processing unit 401.

[0053] Third embodiment The chiller system 100 illustrated in FIG. 5 is configured to have multiple, in this case two, refrigeration cycle units 200 for one user unit 300; in other words, multiple, in this case two, refrigerant pipes 208 correspond to one water pipe 301.

[0054] In this configuration example, the deterioration pattern determination processing unit 405 is capable of determining the deterioration pattern using the capacity of the water heat exchanger 205 estimated in the relationship between one refrigerant pipe 208 and the water pipe 301, and is also capable of determining the deterioration pattern using the capacity of the water heat exchanger 205 estimated in the relationship between the other refrigerant pipe 208 and the water pipe 301.

[0055] Then, when a deterioration pattern is determined using the capacity of the water heat exchanger 205 estimated in the relationship between one refrigerant pipe 208 and the water pipe 301, the notification processing unit 406 can notify that deterioration has occurred in the relationship with the one refrigerant pipe 208. When a deterioration pattern is determined using the capacity of the water heat exchanger 205 estimated in the relationship between the other refrigerant pipe 208 and the water pipe 301, the notification processing unit 406 can notify that deterioration has occurred in the relationship with the other refrigerant pipe 208. That is, according to this configuration example, it is possible to specify which of the multiple refrigerant pipes 208 the water heat exchanger 205 is in relation to and, ultimately, which of the multiple refrigeration cycle units 200 the water heat exchanger 205 is in relation to.

[0056] In addition, even if the deterioration pattern is determined using the capacity of the water heat exchanger 205 estimated in the relationship between any one of the multiple refrigerant pipes 208 and the water pipe 301, the notification processing unit 406 may be configured to notify that deterioration has occurred in the water heat exchanger 205 in relation to all of the multiple refrigerant pipes 208 including the other refrigerant pipes 208.

[0057] (Fourth embodiment) The chiller system 100 illustrated in Fig. 6 has a configuration in which a plurality of water heat exchangers 205, in this case two, are connected in series on one water pipe 301. An intermediate water pressure gauge 323 and an intermediate water temperature gauge 333 are provided in a portion of the water pipe 301 between the plurality of water heat exchangers 205. That is, the configuration example of the fourth embodiment has a configuration in which a plurality of the configurations exemplified in the above-mentioned first embodiment, in this case two, are connected in series. According to this configuration example, the deterioration pattern determination processing unit 405 can determine the deterioration pattern for each of the plurality of water heat exchangers 205.

[0058] Then, when a deterioration pattern is determined for one of the water heat exchangers 205, the notification processing unit 406 can provide a notification that deterioration has occurred in that one water heat exchanger 205. Furthermore, when a deterioration pattern is determined for the other water heat exchanger 205, the notification processing unit 406 can provide a notification that deterioration has occurred in the other water heat exchanger 205. That is, according to this configuration example, it is possible to identify which water heat exchanger 205 has deteriorated.

[0059] In addition, even if a deterioration pattern is determined to exist in any one of the multiple water heat exchangers 205, the notification processing unit 406 may be configured to notify that deterioration has occurred in the entire group of multiple water heat exchangers 205, including the other water heat exchangers 205.

[0060] (Other embodiments) This embodiment is not limited to the above-mentioned embodiments, and various modifications and extensions can be made without departing from the spirit of the present invention. For example, an embodiment may be made by appropriately combining at least two or more of the above-mentioned embodiments. In addition, the differential pressure flow rate, the capacity flow rate, the actual temperature difference, and the estimated temperature difference are not limited to the above-mentioned identification methods, and can be identified using various well-known methods.

[0061] Although several embodiments of the present invention have been described above, these embodiments are presented merely as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. The present embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0062] In the drawing, 205 indicates a water heat exchanger, 205a indicates a heat transfer section, 208 indicates a refrigerant piping, 301 indicates a water piping, 400 indicates a control device (water heat exchanger deterioration diagnosis device), 401 indicates a differential pressure flow rate identification processing unit (differential pressure flow rate identification unit), 402 indicates a capacity flow rate identification processing unit (capacity flow rate identification unit), 403 indicates an actual temperature difference identification processing unit (actual temperature difference identification unit), 404 indicates an estimated temperature difference identification processing unit (estimated temperature difference identification unit), 405 indicates a deterioration pattern determination processing unit (deterioration pattern determination unit), and 407 indicates an actual flow rate identification processing unit (actual flow rate identification unit).

Claims

1. a water heat exchanger including a heat transfer unit between a water pipe through which water flows and a refrigerant pipe through which a refrigerant flows, and performing heat exchange between the water flowing in the water pipe and the refrigerant flowing in the refrigerant pipe via the heat transfer unit; a differential pressure flow rate determination unit that determines a flow rate estimated from a pressure difference between a water pressure in the water pipe upstream of the water heat exchanger and a water pressure in the water pipe downstream of the water heat exchanger as a differential pressure flow rate; a capacity flow rate specification unit that estimates a flow rate of water flowing through the water pipe based on a capacity of the water heat exchanger and specifies the estimated flow rate as a capacity flow rate; an actual temperature difference specifying unit that specifies a temperature difference between a temperature of the water flowing through the water pipe and a temperature of the refrigerant flowing through the refrigerant pipe as an actual temperature difference; an estimated temperature difference specifying unit that estimates a temperature difference between the temperature of the water flowing in the water pipe and the temperature of the refrigerant flowing in the refrigerant pipe based on a capacity of the water heat exchanger and specifies the estimated temperature difference as an estimated temperature difference; a deterioration pattern determination unit that determines a deterioration pattern of the water heat exchanger based on the differential pressure flow rate determined by the differential pressure 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 estimated temperature difference determined by the estimated temperature difference determination unit; and Equipped with The deterioration pattern determination unit is When the differential pressure flow rate specified by the differential pressure flow rate specifying unit is greater than the capacity flow rate specified by the capacity flow rate specifying unit, it is determined that the deterioration pattern of the water heat exchanger is a flow path blockage pattern in which the water pipe is blocked, A deterioration diagnosis device for a water heat exchanger that, when the actual temperature difference identified by the actual temperature difference identification unit is greater than the estimated temperature difference identified by the estimated temperature difference identification unit, determines that the deterioration pattern of the water heat exchanger is a heat transfer inhibition pattern in which the thermal transfer performance of the heat transfer section is inhibited.

2. An actual flow rate specification unit that specifies the flow rate of water actually flowing through the water pipe as an actual flow rate, The deterioration pattern determination unit is A deterioration diagnosis device for a water heat exchanger as described in claim 1, wherein when the differential pressure flow rate determined by the differential pressure flow rate determining unit is greater than the actual flow rate determined by the actual flow rate determining unit, the deterioration pattern of the water heat exchanger is determined to be the flow path blockage pattern.

3. A method for diagnosing deterioration of a water heat exchanger that includes a heat transfer unit between a water pipe through which water flows and a refrigerant pipe through which a refrigerant flows, and that performs heat exchange between the water flowing in the water pipe and the refrigerant flowing in the refrigerant pipe via the heat transfer unit, comprising: A differential pressure flow rate determination process that determines a flow rate estimated from a pressure difference between a water pressure on the upstream side of the water heat exchanger in the water piping and a water pressure on the downstream side of the water heat exchanger in the water piping as a differential pressure flow rate; A capacity flow rate determination process for estimating a flow rate of water flowing through the water pipe based on the capacity of the water heat exchanger and determining the estimated flow rate as a capacity flow rate; an actual temperature difference determination process for determining a temperature difference between the temperature of the water flowing through the water pipe and the temperature of the refrigerant flowing through the refrigerant pipe as an actual temperature difference; an estimated temperature difference determination process for estimating a temperature difference between the temperature of the water flowing through the water pipe and the temperature of the refrigerant flowing through the refrigerant pipe based on a capacity of the water heat exchanger, and determining the estimated temperature difference as an estimated temperature difference; a deterioration pattern determination process for determining a deterioration pattern of the water heat exchanger based on the differential pressure flow rate identified by the differential pressure flow rate identification process, the capacity flow rate identified by the capacity flow rate identification process, the actual temperature difference identified by the actual temperature difference identification process, and the estimated temperature difference identified by the estimated temperature difference identification process; Including, In the deterioration pattern determination process, When the differential pressure flow rate identified by the differential pressure flow rate identification process is greater than the capacity flow rate identified by the capacity flow rate identification process, it is determined that the deterioration pattern of the water heat exchanger is a flow path blockage pattern in which the water pipe is blocked, A deterioration diagnosis method for a water heat exchanger, which determines that the deterioration pattern of the water heat exchanger is a heat transfer inhibition pattern in which the thermal transfer performance of the heat transfer section is inhibited if the actual temperature difference identified by the actual temperature difference identification process is greater than the estimated temperature difference identified by the estimated temperature difference identification process.

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