JP7567548B2 - Heat exchanger abnormality diagnosis device - Google Patents

Description

The present invention relates to a heat exchanger that exchanges heat between a high-temperature fluid and a low-temperature fluid, and more specifically, to a device for diagnosing abnormalities in such a heat exchanger.

Heat exchangers that exchange heat between high-temperature fluids and low-temperature fluids are used in various industrial machines and plants. For example, in a gas turbine engine, high-temperature exhaust gas discharged from a combustor through a turbine and low-temperature compressed air sent to the combustor are passed through the heat exchanger, and heat is transferred from the high-temperature exhaust gas to the low-temperature compressed air, thereby raising the temperature of the compressed air and improving the energy efficiency of the engine. Thus, if there is an abnormality in the heat exchanger, the energy efficiency of the machine or plant that uses it will decrease, so various techniques have been proposed to diagnose abnormalities in the heat exchanger. For example, Patent Document 1 proposes a method for diagnosing abnormalities in a large, complex heat exchanger, in which the heat absorption amount of the heat medium in the heat exchanger is calculated based on data from sensors installed at multiple locations in the heat exchanger, the heat exchanger is divided into multiple blocks, the heat absorption amount of the heat medium is calculated for each block, and the heat absorption amount of the heat exchanger and each block is evaluated using a reference value. In addition, Patent Document 2 proposes that in a heat exchanger in which a first heat exchange passage through which combustion air supplied to a combustion burner of a combustion appliance flows and a second heat exchange passage through which exhaust gas from the combustion burner, which has a higher temperature than the combustion air and a lower oxygen concentration than the combustion air, flows, are stacked via a passage wall, and that the difference between the oxygen concentration of the exhaust gas at the inlet side of the second heat exchange passage and the oxygen concentration of the exhaust gas G at the outlet side of the second heat exchange passage is used to determine whether or not mixing of the combustion air and the exhaust gas has occurred between the first heat exchange passage and the second heat exchange passage.

Patent Publication 2018-190246 Patent Publication 2018-190246

In heat exchangers used in gas turbine engines as described above, which exchange heat between the combustion air supplied to the combustor and the exhaust gas from the combustor, a dense brazed welded structure is adopted to improve heat exchange performance, and since they are used at high temperatures, the fins may collapse due to corrosion, or the welds may be destroyed, causing abnormalities such as fluid leakage (internal short circuit) due to damage to the air flow path or exhaust gas flow path in the heat exchanger, and even external leakage (external short circuit) due to damage to the heat exchanger case. Therefore, in abnormality diagnosis of heat exchangers, it is preferable to be able to identify the cause of the occurrence of such abnormalities or the abnormal location, and to determine whether the heat exchanger should be repaired or replaced. In this regard, it is preferable to have as few sensors as possible for detecting abnormalities in the heat exchanger, and to minimize the time and effort required for diagnosis. In addition, it is possible to detect the temperature of each part of the heat exchanger with a temperature sensor to detect such abnormalities, but the temperature varies depending on the location, and it may be difficult to detect abnormalities. Furthermore, when using an air-fuel ratio sensor in a combustor, the increase in air leakage can be subtle, making accurate diagnosis difficult. On the other hand, the pressure detected by a flow path pressure sensor changes relatively quickly or instantaneously when there is a fluid leak, making it possible to detect the presence or absence of damage to the flow path with relatively high accuracy.

Thus, one objective of the present invention is to enable identification of the cause or location of an abnormality using as few sensors as possible in a device for diagnosing abnormalities in a heat exchanger that performs heat exchange between high-temperature fluids and low-temperature fluids, such as heat exchange between combustion air supplied to a combustor of a gas turbine engine and exhaust gas from the combustor.

According to the present invention, the above problem is solved by providing an abnormality diagnosis device for a heat exchanger in which a high-temperature flow path through which a high-temperature fluid is pumped and a low-temperature flow path through which a low-temperature fluid is pumped are adjacent to each other across a partition wall, and heat is exchanged between the high-temperature fluid and the low-temperature fluid,
an outer container temperature detection means for detecting a temperature inside an outer container in which the heat exchanger is housed;
a high-temperature flow passage inlet pressure detection means for detecting a pressure on the inlet side of the high-temperature flow passage;
a low-temperature flow passage outlet pressure detection means for detecting a pressure on an outlet side of the low-temperature flow passage;
an abnormality determination means for detecting an abnormality in the heat exchanger by referring to the temperature of the outer container, the pressure on the inlet side of the high-temperature flow path, and the pressure on the outlet side of the low-temperature flow path,
This is achieved by an apparatus configured so that the abnormality determination means determines that there is a leak in the case of the heat exchanger in the outer container when a rise in temperature of the outer container compared to normal operation is detected and a drop in pressure on the inlet side of the high-temperature flow path or the outlet side of the low-temperature flow path is detected compared to normal operation, determines that there is a leak due to damage to the high-temperature flow path when there is a drop in pressure on the inlet side of the high-temperature flow path compared to normal operation, and determines that there is a leak due to damage to the low-temperature flow path when there is a drop in pressure on the outlet side of the low-temperature flow path compared to normal operation.

In the above configuration, as already mentioned, the heat exchanger may be a heat exchanger that typically performs heat exchange between combustion air (low temperature fluid) supplied to a combustor such as a gas turbine engine and exhaust gas (high temperature fluid) from the combustor, but is not limited thereto. In such a heat exchanger, a high temperature fluid is pumped from its inlet to its outlet in the "high temperature flow path", and a low temperature fluid is pumped from its inlet to its outlet in the "low temperature flow path", and while the high temperature fluid flows in the high temperature flow path and the low temperature fluid flows in the low temperature flow path, heat is transferred from the high temperature fluid to the low temperature fluid in a state where the fluids are separated by a partition so as not to directly mix. In particular, when the heat exchanger is applied to heat exchange between the exhaust gas and the combustion air of a gas turbine engine, heat exchange is performed between the exhaust gas discharged after passing through the turbine and the compressed air on its way from the compressor to the combustor. The "outer container in which the heat exchanger is housed" may be, for example, a container that houses or contains the entire machine, such as a gas turbine engine, to which it is applied, including the heat exchanger. The "temperature in the outer vessel" may be the temperature at any location in the outer vessel, and typically, the temperature at a location where the temperature does not change when a machine such as a gas turbine engine is operating stably may be measured sequentially by an outer vessel temperature detection means such as a temperature sensor. The "high-temperature passage inlet pressure detection means" and the "low-temperature passage outlet pressure detection means" may each be a pressure sensor that sequentially measures the pressure of the fluid at the corresponding location. In particular, when the heat exchanger is applied to a gas turbine engine, the inlet of the high-temperature passage may be the outlet of the turbine, and the outlet of the low-temperature passage may be the outlet of the low-temperature passage that communicates with the compressor, immediately before being supplied to the combustor. The "abnormality determination means" is configured to detect an abnormality in the heat exchanger by referring to the temperature of the outer vessel, the pressure on the inlet side of the high-temperature passage, and the pressure on the outlet side of the low-temperature passage. The abnormality determination means may be realized by the operation of a computer device or an electronic circuit device.

In the above-mentioned device of the present invention, the abnormality determination means determines that there is a leak in the case of the heat exchanger in the outer container when a rise in the temperature of the outer container is detected compared to normal operation, and a drop in the pressure on the inlet side of the high-temperature flow path or the outlet side of the low-temperature flow path is detected compared to normal operation, determines that there is a leak due to damage to the high-temperature flow path when there is a drop in the pressure on the inlet side of the high-temperature flow path compared to normal operation, and determines that there is a leak due to damage to the low-temperature flow path when there is a drop in the pressure on the outlet side of the low-temperature flow path compared to normal operation. Here, "normal operation" may be a state in which the heat exchanger is operating stably without any abnormalities. The "heat exchanger case" may be an exterior configured so that the high-temperature flow path and the low-temperature flow path are adjacent to each other so as to exchange heat, and is usually configured so that the inside of the case is insulated from the outside of the case so that heat is efficiently transferred from the high-temperature flow path to the low-temperature flow path.

In the configuration of the present invention, if the pressure on the inlet side of the high-temperature flow path is lower than that during normal operation, it is considered that there is a damaged part in the high-temperature flow path from which the high-temperature fluid is leaking. Similarly, if the pressure on the outlet side of the low-temperature flow path is lower than that during normal operation, it is considered that there is a damaged part in the low-temperature flow path from which the low-temperature fluid is leaking. Furthermore, if there is a pressure drop as described above and the temperature inside the outer container is higher than that during normal operation, it is further considered that the case of the heat exchanger is damaged and the high-temperature or low-temperature fluid is leaking outside the case of the heat exchanger (if there is no increase in the temperature inside the outer container, it is considered that there is no damage to the case of the heat exchanger and the fluid is leaking inside the heat exchanger. Furthermore, if only a rise in temperature inside the outer container is observed and the above-mentioned pressure drop is not observed, it is possible that the abnormality is something other than the heat exchanger). Thus, with the above configuration, by referring to the pressure on the inlet side of the high-temperature flow path, the pressure on the outlet side of the low-temperature flow path, and the temperature inside the outer container, it is possible to determine whether or not a significant leak has occurred in the high-temperature flow path, the low-temperature flow path, or the heat exchanger case of the heat exchanger, and depending on whether an abnormality is observed in the pressure or temperature, it is possible to identify the location of the abnormality.

In one embodiment, it may be determined that there is a leak in the high-temperature flow path when the pressure on the inlet side of the high-temperature flow path is lower than during normal operation by a predetermined change width that may be set arbitrarily, and it may be determined that there is a leak in the low-temperature flow path when the pressure on the outlet side of the low-temperature flow path is lower than during normal operation by a predetermined change width that may be set arbitrarily. Also, when there is a pressure drop as described above in the inlet side pressure of the high-temperature flow path or the outlet side pressure of the low-temperature flow path, it may be determined that there is a leak in the heat exchanger case when the temperature of the outer container rises above the value during normal operation by a predetermined change width that may be set arbitrarily.

However, if the heat exchanger is a heat exchanger that exchanges heat between the combustion air supplied to the combustor of an internal combustion engine such as a gas turbine engine and the exhaust gas from the combustor, as the degree of leakage in each part of the heat exchanger increases, the thermal efficiency of the internal combustion engine decreases, and the amount of fuel required per unit time for the internal combustion engine to generate a certain output increases. Therefore, in the case of a heat exchanger configured as described above, it is possible to grasp the degree of leakage in each part of the heat exchanger by sequentially observing the amount of fuel supplied to the combustor. Thus, in the device of the present invention, a means for monitoring the amount of fuel supplied to the combustor may be further provided, making it possible to evaluate the degree of leakage in each part of the heat exchanger.

In an embodiment, the abnormality diagnosis device of the present invention may be configured to, as described above, refer to the pressure on the inlet side of the high-temperature flow path, the pressure on the outlet side of the low-temperature flow path, the temperature inside the outer container, or even the amount of fuel supplied to the combustor, and when it is determined that there is a significant amount of leakage in each part of the heat exchanger, determine that the level of leakage in each part of the heat exchanger is such that maintenance or repair of the heat exchanger is required, and present the need for maintenance or repair of the heat exchanger. This allows the user to carry out maintenance or repair of the heat exchanger at the appropriate time.

Thus, in the heat exchanger abnormality diagnosis device of the present invention, by monitoring the high-temperature passage inlet pressure, the low-temperature passage outlet pressure, and the temperature inside the outer vessel, if a leak occurs in any part of the heat exchanger, it is possible to detect the leak and identify the part where the leak has occurred. The detection means required for abnormality diagnosis in the device of the present invention are relatively small in number and are means normally used in the control and monitoring of internal combustion engines such as gas turbine engines, so that it does not require special sensors or multiple temperature sensors and can be constructed relatively inexpensively. The configuration of the present invention can be advantageously used, for example, in heat exchangers used in small gas turbine engines for cogeneration power generation (in this case, the temperature inside the outer vessel is the temperature inside the package that houses the gas turbine engine).

Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

Fig. 1(A) is a schematic diagram showing the schematic configuration of a gas turbine engine to which a heat exchanger abnormality diagnosis device according to the present embodiment is applied, and Fig. 1(B) is a schematic diagram of a heat exchanger to which the abnormality diagnosis device according to the present embodiment is applied. FIG. 2 is a diagram showing, in the form of a flow chart, the processing carried out by the heat exchanger abnormality diagnostic device according to this embodiment.

Reference Signs List 1: Gas turbine engine 2: Combustor 3: Compressor 4: Rotating shaft 5: Turbine 6: Heat exchanger 6a: Compressed air flow path of heat exchanger (low temperature flow path)
6b... Exhaust gas flow path of heat exchanger (high temperature flow path)
6c... Heat exchanger case 10... Gas turbine engine case (package)
Ar...air pAr...compressed air BG...combustion gas WG...exhaust gas 50...abnormality diagnosis device

1A, the abnormality diagnosis device for a heat exchanger according to the present embodiment is used , for example, to detect an abnormality in a heat exchanger 6 installed in a gas turbine engine 1. The gas turbine engine 1 may be, for example, a small-sized gas turbine engine for cogeneration power generation. More specifically, the gas turbine engine 1 has a combustor 2, a compressor 3, and a turbine 5. The combustor 2 mixes and burns a fuel FL supplied from a fuel supply line with compressed air pAr, which is obtained by compressing air Ar taken in from the atmosphere by the compressor 3 and passing through a heat exchanger 6, and delivers a high-temperature, high-pressure combustion gas BG. The fuel may be any fuel normally used as fuel for a gas turbine engine, or may be any gas (unburned gas) that has room for combustion in the exhaust gas of an industrial machine or a transport machine in a facility such as a factory. The turbine 5 is rotated by the combustion gas BG from the combustor 2, and the rotation of the turbine 5 rotates the compressor 3, which compresses the air Ar taken in from the atmosphere as described above and delivers it to the combustor 2. In addition, any machine or equipment such as a generator is connected to the rotating shaft 4 of the turbine 5, and the rotational energy of the turbine 5 is recovered by the machine or equipment such as a generator or used as energy for operating the machine. Furthermore, since the exhaust gas WG discharged from the turbine 5 has a high temperature, its thermal energy is utilized to raise the temperature of the compressed air pAr to be fed to the combustor 2, and in order to improve the energy efficiency, in the heat exchanger 6, a flow path 6b for the exhaust gas WG and a flow path 6a for the compressed air pAr pass through in thermal contact, and the thermal energy of the exhaust gas WG is transferred to the compressed air pAr. More specifically, as shown in FIG. 1B, the heat exchanger 6 has a structure in which the flow path 6a through which the compressed air pAr flows and the flow path 6b through which the exhaust gas WG flows are physically partitioned alternately by a thermally conductive partition wall 6w, and the structure is housed in a case 6c so as to extend so as to be in thermal contact over as wide an area as possible. In this configuration, in the compressed air flow path 6a, compressed air is pressure-fed from the compressor 3 toward the combustor 2, and in the exhaust gas flow path 6b, exhaust gas is pressure-fed from the combustor 2 through the turbine 5. It is preferable that the case 6c is configured so that the inside of the case is insulated from the outside so that heat is efficiently transferred from the high-temperature flow path to the low-temperature flow path. The combustor 2, compressor 3, turbine 5, heat exchanger 6, and fluid pipes for transporting fluids among them are contained in a container (package or cubicle) 10.

In the above gas turbine engine, the measurement items necessary for its control and monitoring include the atmospheric temperature T0, the temperature inside the package Tp, the compressed air temperature P3 at the compressor outlet, the compressed air temperature T35 at the heat exchanger outlet, the compressed air pressure P35, the exhaust gas temperature T6 at the turbine outlet, the exhaust gas pressure P6, and the fuel flow rate Gf to the combustor. Each measurement value may be measured by a corresponding sensor means. As for the temperature inside the package Tp, the temperature of a location where the temperature does not change when the gas turbine engine is operating stably may be measured sequentially by an outer container temperature detection means such as a temperature sensor. The atmospheric temperature, the temperature and pressure of the compressed air and the exhaust gas may be measured in a normal manner. Of these items, in this embodiment, for the abnormality diagnosis of the heat exchanger described later, the compressed air pressure P35 at the heat exchanger outlet, the exhaust gas pressure P6 at the turbine outlet, and the temperature inside the package Tp are used to detect the presence or absence of an abnormality in the heat exchanger and the abnormal part, and the fuel flow rate Gf may be used to monitor the progress of such an abnormality. Specifically, the abnormality diagnosis device 50 performs the abnormality diagnosis in the heat exchanger in a manner described later, by referring to the compressed air pressure P35, exhaust gas pressure P6, temperature Tp inside the package, and fuel flow rate Gf, each measured by a sensor means. The abnormality diagnosis device 50 may be configured by a computer device including a computer and a drive circuit having a CPU, ROM, RAM, and input/output port device interconnected by a normal bidirectional common bus, and its operation may be realized by the operation of the computer device according to a program.

Heat Exchanger Abnormality Diagnosis The heat exchanger 6 of the gas turbine engine 1 described above typically adopts a dense brazed welded structure to improve heat transfer performance, and is used at high temperatures, so there is a possibility that damage or destruction may occur due to corrosion or high temperatures, in which case fluid leakage occurs in the flow path 6a, the flow path 6b, or the case 6c. This will result in a decrease in heat exchange performance, which in turn will decrease the fuel efficiency of the engine, and in such a case, it is necessary to improve the fuel efficiency by prompt repair or part replacement. Therefore, it is necessary to monitor and detect leakage due to damage to the flow path or case in the heat exchanger 6 (abnormality diagnosis). In such abnormality diagnosis, it is preferable to be able to identify the reason or abnormality location when an abnormality occurs using as few sensors as possible.

Regarding this point, as already mentioned, in the compressed air passage 6a, compressed air is pumped under pressure from the compressor 3. When there is a leak in the compressed air passage 6a, the compressor 3 changes its operation to increase the air flow, and the pressure at the inlet of the compressor 3 decreases. This reduces the pressure loss (pressure difference between the inlet and outlet) in the compressed air passage 6a, and the pressure P35 of the compressed air at the outlet of the heat exchanger 6 decreases. Therefore, by monitoring the pressure P35 of the compressed air at the outlet of the heat exchanger 6, a leak in the compressed air passage 6a can be detected. In addition, in the exhaust gas passage 6b, exhaust gas is pumped under pressure from the combustor 2 through the turbine 5. When there is a leak in the exhaust gas passage 6b (the outlet of the exhaust gas passage 6b is at atmospheric pressure), the pressure loss in the exhaust gas passage 6b decreases, and the pressure at the outlet of the turbine 5 decreases. Therefore, by monitoring the pressure P5 of the exhaust gas at the outlet of the turbine 5, a leak in the exhaust gas passage 6b can be detected. Furthermore, in the situation where any of the above pressure drops occur, if the case 6c of the heat exchanger 6 is also damaged and fluid is leaking out, the fluid is hot and the temperature Tp inside the package rises, so by monitoring the temperature Tp inside the package, leakage from the case 6c can be detected. Also, the more the abnormality in the heat exchanger progresses, the lower the energy efficiency becomes. In that case, the internal combustion engine will increase the amount of fuel supplied to the combustor to maintain output. Therefore, by monitoring the increase in the fuel flow rate Gf, the degree of progression of the abnormality in the heat exchanger can be detected.

In this embodiment, as described above, the compressed air pressure P35, exhaust gas pressure P6, temperature inside the package Tp, and even fuel flow rate Gf are referenced to determine whether there is an abnormality in the heat exchanger, identify the abnormal part, and monitor the progress of the abnormality. Note that by referring to pressure rather than temperature when determining whether there is an abnormality in the flow path inside the heat exchanger, it is expected that a more accurate determination can be made without being affected by temperature unevenness.

The relationship between the state of the detection value measured by the sensor means and an abnormality occurring in the heat exchanger is as follows: In the following, "normal" refers to the temperature or pressure when there is no abnormality.
(a) When the package temperature Tp is higher than normal and the exhaust gas pressure P6 is lower than normal ← The exhaust gas flow path 6b and the case 6c are damaged, causing exhaust gas to leak outside the case, resulting in an increase in the package temperature Tp and a decrease in the exhaust gas pressure P6.
(b) When the package temperature Tp is higher than normal and the compressed air pressure P35 is lower than normal ← The compressed air flow path 6a and the case 6c are damaged, causing compressed air to leak outside the case, resulting in an increase in the package temperature Tp and a decrease in the compressed air pressure P35.
(c) When exhaust gas pressure P6 is lower than normal (package temperature Tp does not increase) ← The exhaust gas flow path 6b is damaged, causing exhaust gas to leak into the case, resulting in a decrease in exhaust gas pressure P6 (since the exhaust gas remains in the case, (package temperature Tp does not increase)).
(d) When the compressed air pressure P35 is lower than normal (the package temperature Tp does not increase) ← The compressed air flow path 6a is damaged, causing compressed air to leak into the case, resulting in a decrease in the compressed air pressure P35 (since the compressed air remains in the case, the package temperature Tp does not increase).
Thus, by referring to the compressed air pressure P35, the exhaust gas pressure P6, and the temperature inside the package Tp, it is possible to identify the location where the abnormality has occurred when an abnormality occurs in the heat exchanger, based on which of the measured values has changed.

When the abnormality of the heat exchanger progresses to a considerable extent, it is preferable to notify the user that immediate repair, part replacement, or other maintenance is required. In this regard, the degree of abnormality of the heat exchanger can be detected from the range of change in the compressed air pressure P35, exhaust gas pressure P6, and temperature inside the package Tp, and, as already mentioned, can also be detected from an increase in the fuel flow rate Gf. Therefore, in the abnormality diagnosis device of this embodiment, when the range of change from normal in any of the compressed air pressure P35, exhaust gas pressure P6, temperature inside the package Tp, and fuel flow rate Gf reaches a respective predetermined threshold, the need for maintenance may be notified. Each predetermined threshold can be determined in advance by experiment, etc.

Abnormality Diagnosis Processing The abnormality diagnosis device 50 may execute the processing as shown in Fig. 2. In the processing, first, the compressed air pressure P35, the exhaust gas pressure P6, the temperature Tp inside the package, and the fuel flow rate Gf are detected (step 1). Next, for the compressed air pressure P35 and the exhaust gas pressure P6, it is determined whether or not the deviations ΔP35 and ΔP6 from the normal values are smaller than a significant negative value -ε that may be set appropriately (steps 2 and 4). The normal value is a value that is normally obtained when there is no abnormality in the heat exchanger at the current output of the gas turbine engine, and may be determined in advance by experiments or the like. -ε in steps 2 and 4 may be the same value or different values. Here, when ΔP35<-ε or ΔP6<-ε is established, as can be understood from the relationship between the above-mentioned detection value state and the abnormality occurring in the heat exchanger, it can be determined that a significant fluid leakage due to damage has occurred in the compressed air flow path 6a or the exhaust gas flow path 6b (steps 3 and 5). Note that when it is determined that the compressed air flow path 6a or the exhaust gas flow path 6b is damaged, the flag F is set to 1 (F=0 in the initial state).

Next, it is determined whether the deviation ΔTp of the temperature Tp inside the package from the normal value is greater than a significant positive value ε that may be set appropriately (step 6). The normal value is a value that is normally obtained when there is no abnormality in the heat exchanger at the current output of the gas turbine engine, and may be determined in advance by experiment or the like. ε may be the same value as above, or a different value. Here, when F=1, that is, when it is determined that there is a significant leakage of fluid due to damage to the compressed air flow path 6a or the exhaust gas flow path 6b, if ΔTp>ε is established, it is determined that damage has occurred in the case 6c and that fluid is leaking outside the heat exchanger 6 (step 7).

In the above process, it is determined whether or not there is a significant leak due to damage to the compressed air passage 6a, the exhaust gas passage 6b, or the case 6c, and the location of the abnormality is identified. If the presence of a leak is detected and the degree of progression is considerable, a notification of the need for maintenance is displayed. Specifically, the notification of the need for maintenance may be displayed (step 9) when any of the following conditions is met (step 8):
(i) ΔGf>γ
When the increase ΔGf in the amount of fuel supplied to the combustor from the normal state exceeds a predetermined threshold value γ (>0).
(ii) ΔP35<π35
When the decrease ΔP35 of the compressed air pressure P35 from the normal value falls below a predetermined threshold value π35 (<0).
(iii) ΔP6<π6
When the decrease ΔP6 of the exhaust gas pressure P6 from the normal value falls below a predetermined threshold value π6 (<0).
(iv) ΔTp>τ
When the increase ΔTp of the package internal temperature Tp from the normal value exceeds a predetermined threshold τ (>0).
The above-mentioned predetermined threshold value may be appropriately determined by experiment, etc. The determination of whether or not to present the necessity of maintenance (step 8) may use the condition regarding the fuel amount in (i), and the identification of the abnormality may refer to the results of steps 3, 5, and 7.

Thus, the device of this embodiment described above can determine the presence or absence of a heat exchanger failure, its location, and its severity without using any special sensors, and can suggest repair locations and appropriate replacement times.

The above description is given in relation to an embodiment of the present invention, but many modifications and changes are easily possible for those skilled in the art, and it is clear that the present invention is not limited to the embodiment exemplified above, but can be applied to various devices without departing from the concept of the present invention.

Claims (1)

1. An abnormality diagnosis device for a heat exchanger, the high-temperature flow path through which a high-temperature fluid is pumped and the low-temperature flow path through which a low-temperature fluid is pumped being adjacent to each other across a partition wall, the high-temperature fluid and the low-temperature fluid being pumped between the high-temperature fluid and the low-temperature fluid,
an outer container temperature detection means for detecting a temperature inside an outer container in which the heat exchanger is housed;
a high-temperature flow passage inlet pressure detection means for detecting a pressure on the inlet side of the high-temperature flow passage;
a low-temperature flow passage outlet pressure detection means for detecting a pressure on an outlet side of the low-temperature flow passage;
an abnormality determination means for detecting an abnormality in the heat exchanger by referring to the temperature of the outer container, the pressure on the inlet side of the high-temperature flow path, and the pressure on the outlet side of the low-temperature flow path,
The device is configured so that, when a rise in temperature of the outer container is detected compared to normal operation and a drop in pressure on the inlet side of the high-temperature flow path or the outlet side of the low-temperature flow path is detected compared to normal operation, the abnormality determination means determines that there is a leak in the case of the heat exchanger in the outer container, when there is a drop in pressure on the inlet side of the high-temperature flow path compared to normal operation, the device determines that there is a leak due to damage to the high-temperature flow path, and when there is a drop in pressure on the outlet side of the low-temperature flow path compared to normal operation, the device determines that there is a leak due to damage to the low-temperature flow path.

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