JP6940983B2 - Performance diagnosis device and performance diagnosis method for absorption chillers - Google Patents

Description

The present invention relates to a performance diagnosis device and a performance diagnosis method for an absorption chiller.

When the efficiency of the refrigerator decreases, it is necessary to promptly identify the cause and perform maintenance.

Patent Document 1 shows the actual performance under the evaluation operation condition based on the evaluation operation condition data for the purpose of accurately separating the tube cleaning and the overhaul as the maintenance contents to be performed for the performance deterioration of the refrigerator. The evaluation actual COP and the evaluation reference LTD are calculated, and the COP change amount indicating the difference between the evaluation actual COP and the evaluation reference COP and the LTD change amount indicating the difference between the evaluation actual LTD and the evaluation reference LTD are calculated. , A refrigerator deterioration diagnosis device and a refrigerator deterioration diagnosis method that classify cases according to whether or not the change amount ratio R between the COP change amount and the LTD change amount at the time of evaluation is within a certain determination region Q are disclosed. There is. Further, in Patent Document 1, when the change amount ratio R is within the constant determination area Q, tube cleaning is selected as the maintenance type when performing maintenance on the refrigerator, and the change amount ratio R is outside the determination area Q. If, it is disclosed that overhaul is selected as the maintenance type. Here, LTD is an abbreviation for Leaving Temperature Difference, which is one of the indexes indicating the performance of the refrigerator.

Japanese Unexamined Patent Publication No. 2016-205640

In the refrigerator deterioration diagnosis method described in Patent Document 1, if the cause of the change in COP is other than dirt on the cooling water piping, it is determined that the cooling water is overhauled, and it is not possible to know where the problem is occurring. .. Therefore, the repair cost may be higher than necessary.

An object of the present invention is to identify a component that causes a change in performance when the performance of the absorption chiller changes.

The performance diagnosis device of the absorption chiller of the present invention includes an efficiency calculation unit that calculates the efficiency of the absorption chiller, a performance determination unit that determines whether the efficiency of the absorption chiller is normal, and an absorption chiller. Includes an element diagnostic unit that calculates the performance of each component of. When the performance determination unit determines that the efficiency of the absorption chiller deviates from a predetermined range, the element diagnosis unit may perform one or more of the plurality of components of the absorption chiller. When any of the above measured values deviates from the predetermined range for the index, it is determined that the component is abnormal. ..

According to the present invention, when the performance of the absorption chiller changes, the component causing the performance change can be identified. As a result, the performance of the absorption chiller can be restored at a reasonable repair cost.

It is a block diagram which shows the structure of the double-effect absorption chiller of Example 1 and the installation position of the measurement sensor. It is a block diagram which shows the example of the performance diagnostic apparatus of the absorption chiller. It is a flowchart which shows the performance diagnosis method of the refrigerator of an Example. It is a graph which shows the relationship between refrigerating capacity and efficiency. It is a graph which shows the relationship between the refrigerating capacity and the absorbent concentration in a high temperature regenerator. It is a graph which shows the example of how to obtain the degree of abnormality. It is a graph which shows the time-dependent change of the degree of abnormality. It is a flowchart which shows the calculation process of the degree of abnormality illustrated in FIG. It is a block diagram which shows the structure of the double-effect absorption chiller of Example 2 and the installation position of the measurement sensor. This is an example of a display screen of a part of the measurement data 50 and the performance index value in FIG. This is an example of the second screen that displays detailed information such as the degree of abnormality of the absorption chiller.

The present invention diagnoses the cause when the performance of the refrigerator changes. By using the present invention, it is possible to diagnose the performance and the cause even when the refrigerating capacity is low. Further, according to the present invention, it is possible to perform a diagnosis for each component of the refrigerator and identify a portion where the performance is deteriorated.

In the present invention, the efficiency of the refrigerator is obtained from the refrigerating capacity and the amount of heat consumed or the amount of heat input, and the normal value of each component is compared with the measured value or the index measured value calculated from the measured value. Diagnose the state of the element.

For absorption chillers, the components include evaporators, condensers, solution heat exchangers, regenerators and absorbers.

When it is determined that there is an abnormality in the component, the content is output.

The element diagnosis unit calculates the formula of the predicted approximate line showing the relationship between the measured value of one or more of the indexes of the plurality of components and the measured refrigerating capacity, and the measured value corresponding to the rated refrigerating capacity. Calculate the predicted value of the index related to, and compare the normal value of the index with the predicted value.

The element diagnosis unit calculates the degree of abnormality, which is the difference between the normal value and the predicted value corresponding to the rated refrigerating capacity, and manages them in chronological order.

When the degree of abnormality exceeds a predetermined threshold value, or when the rate of increase in the degree of abnormality is larger than a predetermined value, the element diagnosis unit warns about the component indicating the abnormality. Is output.

Hereinafter, examples will be described with reference to the drawings.

FIG. 1 shows the double-effect absorption chiller of the example.

In this figure, the absorption chiller includes an evaporator 1, an absorber 2, a high temperature regenerator 3, a low temperature regenerator 4, a condenser 5, a low temperature heat exchanger 6, and a high temperature heat exchanger 7. The low temperature heat exchanger 6 and the high temperature heat exchanger 7 may be referred to as solution heat exchangers.

An example in which water is used as the refrigerant and an aqueous solution of lithium bromide is used as the absorbing liquid will be described.

The evaporator 1 has a pipe through which cold water passes. The inside of the evaporator 1 is in a decompressed state in which air is removed and is lower than the atmospheric pressure, and the gas phase is kept in a state of being substantially filled with water vapor only. The refrigerant accumulated at the bottom of the evaporator 1 is sprayed on the cold water pipe by the refrigerant pump 40 and evaporates. The water in the chilled water pipe is cooled because heat is taken away by the heat of vaporization of the refrigerant. The refrigerant (water) inside the evaporator 1 is set to evaporate at about 4 ° C. by heat exchange with cold water.

The vaporized refrigerant is absorbed by the lithium bromide aqueous solution in the absorber 2. The lower the temperature of the lithium bromide aqueous solution, the easier it is to absorb vapor. Therefore, the lithium bromide aqueous solution is cooled by flowing the cooling water through the cooling water pipe provided inside the absorber 2 and spraying the lithium bromide aqueous solution outside the pipe. It has become so.

The absorption liquid whose concentration of lithium bromide is reduced by absorbing the refrigerant vapor is sent from the absorber 2 to the high temperature regenerator 3 by the solution pump 41. Meanwhile, the absorbing liquid passes through the low temperature heat exchanger 6 and the high temperature heat exchanger 7. By heating the absorption liquid in the heating unit 8, the refrigerant in the absorption liquid is evaporated and separated, and the absorption liquid is concentrated. City gas, heavy oil, steam, or the like is used as the heating source of the heating unit 8. The temperature of the absorbing liquid in the high temperature regenerator 3 is measured by the high temperature regenerator temperature sensor 17.

The refrigerant evaporated in the high temperature regenerator 3 is sent to the condenser 5 via the drain pipe. The drain pipe passes through the inside of the low temperature regenerator 4 on the way. At that time, the high-temperature refrigerant passing through the drain pipe and the absorbing liquid sent to the inside of the low-temperature regenerator 4 and sprayed are heat-exchanged. The absorbing liquid sent to the low temperature regenerator 4 is sent via a pipe branched between the low temperature heat exchanger 6 and the high temperature heat exchanger 7. The refrigerant generated from the absorbing liquid heated by the low temperature regenerator 4 is sent to the condenser 5. The absorption liquid concentrated by the high temperature regenerator 3 and the low temperature regenerator 4 is sent to the low temperature heat exchanger 6 by the solution spray pump 42, and the absorber 2 absorbs the refrigerant vapor to exchange heat with the diluted absorption liquid. Then, it is returned to the absorber 2.

The condenser 5 has a pipe through which cooling water passes. The refrigerant vapor generated by the high-temperature regenerator 3 and the low-temperature regenerator 4 is sent to the condenser 5, becomes a liquid by heat exchange with the cooling water pipe, and accumulates at the bottom of the condenser 5. The accumulated refrigerant is sent to the evaporator 1.

The low-temperature heat exchanger 6 and the high-temperature heat exchanger 7 apply the heat of the high-temperature absorption liquid to the low-temperature absorption liquid in the process of flowing the absorption liquid from the absorber 2 to the high-temperature regenerator 3. As a result, the low-temperature absorbing liquid is preheated, and the fuel of the heating source of the heating unit 8 is saved.

The cold water pipe is connected to the indoor unit, and the cooling water pipe is connected to the cooling tower.

FIG. 2 shows a configuration example of a performance diagnostic device for an absorption chiller.

In this figure, the performance diagnostic device has the measurement data 50 and the arithmetic unit 51. The measurement data 50 includes the chilled water inlet temperature, the chilled water outlet temperature, the chilled water flow rate, and the like. The arithmetic unit 51 has an efficiency arithmetic unit, a performance determination unit, and an element diagnosis unit.

The efficiency calculation unit takes in the measurement data 50 and calculates the refrigerating capacity, the efficiency of the refrigerator, and the like.

The calculated efficiency of the refrigerator is determined by the performance determination unit as to whether or not it is an abnormal value. If it is an abnormal value, the value is sent to the element diagnosis unit, and the performance of each component is calculated by the element diagnosis unit. The element diagnosis unit calculates the performance index value or the degree of abnormality of each component, and outputs the result to the output unit.

The calculation result can be displayed on another display device through the network. The calculation result can also be stored in the recording device via the network. It is not necessary to have a network, but the presence of a network makes it possible to grasp the state of the device even at a remote location.

Further, the arithmetic unit 51 may be attached to the absorption chiller as a function of the absorption chiller, but the arithmetic unit 51 may be arranged on a server or the like by connecting the measurement data 50 to the network. By arranging the arithmetic unit 51 on a server or the like, restrictions such as calculation speed and recording capacity are almost eliminated, the calculation processing capacity is improved, and the measurement data 50 and the calculation result can be recorded for decades. .. Further, the calculation process may be distributed processing through the network. The recorded measurement data and calculation results can be viewed from anywhere in the world, although access is restricted by security, as long as they are connected to the network.

As shown in FIG. 1, the absorption chiller is equipped with a sensor for diagnosing the performance of each component.

Cold water pipe, cold water for measuring the cold water inlet temperature sensor 11 for measuring the cold water inlet temperature T _{a_in,} coolant outlet temperature sensor 12 for measuring the cold water outlet temperature T _{a_out,} and coolant flow rate V _a A flow rate sensor 60 is provided. An ultrasonic flow meter or the like may be used to measure the flow rate of chilled water, but the flow rate may be obtained from the difference pressure between the inlet pressure of chilled water and the outlet pressure of chilled water. Since the flow meter is more expensive than the pressure meter, the cost for measuring the flow rate can be reduced by using the pressure meter.

The refrigerating capacity R _c is calculated by the following formula (1) using the chilled water flow rate V _a , the chilled water specific heat C _a, and the chilled water density Ρ _a.

The cooling water piping, cooling water inlet temperature sensor 14 for measuring the inlet temperature T _{Co_in} cooling water, the cooling water outlet temperature sensor 15 for measuring the outlet temperature T _{Co_out} of coolant, and the coolant flow rate V A cooling water flow rate sensor 61 for measuring _{co is provided.} To measure the flow rate Ρ _{co of the} cooling water, an ultrasonic flow meter or a pressure gauge is used in the same way as the cold water.

In addition, when it is known in advance that the flow rate does not change, or when it is difficult to install a sensor for flow rate measurement, the flow rate value at the time of equipment installation is used to calculate the refrigerating capacity and heat dissipation amount. It is not necessary to measure at all times. By not constantly measuring the flow rate, the electricity bill and data memory can be reduced.

The heat radiation amount R _r is calculated by the following formula (2) using the cooling water flow rate V _co , the cooling water specific heat C _co, and the cooling water density Ρ _co.

The efficiency of the refrigerator is calculated by the following formula (3) or (4).

When the flow rate of the heating source of the heating unit 8 such as gas or heavy oil can be measured, the COP (efficiency) of the above formula (3) is calculated. If the flow rate of the heating source of the heating unit 8 cannot be measured even with gas or heavy oil, or if it is difficult to measure the amount of heat consumed by the heating unit 8 such as steam-fired or hot-water-fired, the cycle of the above formula (4) Calculate COP. These calculations are performed by the efficiency calculation unit.

FIG. 3 is a flowchart showing a diagnostic processing process in the performance diagnostic apparatus of the refrigerator of the present invention.

The efficiency calculation unit calculates the efficiency of the refrigerator (step S1), and the performance determination unit determines whether the efficiency of the refrigerator is normal (step S2). In step S2, if the efficiency of the refrigerator is normal, the process ends. On the other hand, if the efficiency of the refrigerator is abnormal, each component (component) is diagnosed by the element diagnosis unit (step S3).

The degree of abnormality of each element is displayed on the output unit (terminal screen, data printing machine, etc.) (step S4). This makes it possible to visualize and confirm the causative factor when the efficiency is reduced. By visualizing the causative factors, it is possible to quickly maintain the absorption chiller. Further, the efficiency of the absorption chiller and the degree of abnormality of each element may be calculated in advance before diagnosing the performance of the chiller. You can save time.

FIG. 4 is a graph showing an example of COP (efficiency) in a normal state with respect to the refrigerating capacity when the rated refrigerating capacity is 1. The horizontal axis is the ratio to the rated refrigerating capacity (refrigerating capacity ratio), and the vertical axis is COP (efficiency). Here, the refrigerating capacity ratio is the ratio of the measured refrigerating capacity to the rated refrigerating capacity.

In this figure, the curve is convex upward, and the COP (efficiency) is maximum when the refrigerating capacity ratio is around 0.4.

Regarding the refrigerating capacity during operation, it is desirable to compare the COP during operation with the COP during normal operation. In the performance determination unit, for example, if the COP value is within ± 7% of the normal value, it is determined to be normal, and if it is outside this range, it is determined to be abnormal.

Further, since the amount of change in the value of COP for each ability is small, it is normal if it is within ± 10% of the average COP in the normal state, for example, the average value of 1.35 in the graph of FIG. If it is out of this range, it may be judged as abnormal.

The element diagnosis unit determines the performance of the components of the absorption chiller. _{The chilled water outlet temperature Ta_out} and the evaporation temperature T _eva are used for the diagnosis of the evaporator 1. Since it is difficult to measure the evaporation temperature _Teva by installing a temperature sensor near the chilled water pipe in the evaporator 1, an evaporator refrigerant temperature sensor 13 is installed near the outlet of the evaporator 1 and measured as necessary. The value is corrected to obtain the evaporation temperature T _eva . _{If the evaporation temperature Teva} rises when the chilled water flow rate is constant, the degree of vacuum of the evaporator 1 may be deteriorated.

A chilled water pipe passes through the evaporator 1, and when the inside of the chilled water pipe becomes dirty, the value of the evaporator LTD (Leaving Temperature Difference) becomes larger than the normal value. The evaporator LTD is calculated by the following formula (5).

Further, as another method for determining the performance of the evaporator 1, the value of KAe represented by the following formula (6) may be used. If the heat transfer performance deteriorates due to dirt on the cold water pipe or the like, the KAe value decreases.

Further, as another method for diagnosing the performance of the evaporator 1, the temperature efficiency η _A represented by the following formula (7) may be used for evaluation.

In the above formulas (5) to (7), the performance of the evaporator 1 may be diagnosed using only one of them, or all of them may be used. By using all of them, more accurate diagnosis becomes possible.

For the diagnosis of the absorber 2, the concentration of the absorbent (lithium bromide) contained in the absorber 2 is used. When an abnormality of the solution pump or solution spray pump for sending the absorbent liquid, clogging of the pipe due to crystal precipitation, or the like occurs, the concentration of the absorbent contained in the absorber 2 changes. The concentration of the absorbent is corrected by the absorber outlet temperature sensor 16 as necessary, the equilibrium temperature of the absorbent liquid inside the absorber 2 is calculated, and the chilled water outlet temperature is corrected as necessary. , Calculated by obtaining the saturation temperature of the refrigerant.

For the diagnosis of the high temperature regenerator 3, the concentration of the absorbent contained in the high temperature regenerator 3 and the pressure of the high temperature regenerator 3 are used. If an abnormality occurs in the solution pump or solution spray pump for sending the absorbent liquid, or if the piping is clogged due to crystal precipitation or the like, the concentration of the absorbent becomes higher than the normal value. For the concentration of the absorbent contained in the high temperature regenerator 3, the equilibrium temperature of the absorbent liquid in the high temperature regenerator 3 is calculated from the high temperature regenerator outlet temperature measured by the high temperature regenerator outlet temperature sensor 22, and the low temperature regenerator refrigerant is used. It is calculated by obtaining the saturation temperature in the high temperature regenerator 3 from the temperature sensor 20.

When the low-temperature regenerator refrigerant temperature sensor 20 cannot be installed, the concentration of the absorbent in the high-temperature regenerator 3 is calculated from the pressure of the high-temperature regenerator 3. Further, the performance may be diagnosed by the pressure value of the high temperature regenerator 3.

FIG. 5 is a graph showing an example of the absorbent concentration of the high temperature regenerator 3 under normal conditions with respect to the refrigerating capacity when the rated refrigerating capacity is 1. The horizontal axis represents the ratio to the rated refrigerating capacity, and the vertical axis represents the absorbent concentration of the high temperature regenerator 3.

As shown in this figure, the absorbent concentration of the high temperature regenerator 3 in the normal state changes with respect to the refrigerating capacity. As the refrigerating capacity increases, the absorbent concentration of the high temperature regenerator 3 tends to increase. Therefore, in the refrigerating capacity during operation, it is diagnosed whether or not it is normal by comparing with the concentration at normal time. For example, if it is within ± 5% of the absorbent concentration of the high temperature regenerator 3 in the normal state, it is judged to be normal, and if it is not, it is judged to be abnormal. If the measured value is out of the normal range in the figure, it is judged to be abnormal.

For the diagnosis of the low temperature regenerator 4, the concentration of the absorbent contained in the low temperature regenerator 4 is used. The low temperature regenerator solution outlet temperature sensor 21 is corrected as necessary to calculate the equilibrium temperature of the absorbed liquid inside the low temperature regenerator 4, and from the condenser refrigerant temperature sensor 19 installed near the outlet of the condenser 5. If necessary, the saturation temperature of the refrigerant inside the low temperature regenerator 4 is calculated, and the concentration of the absorbent contained in the low temperature regenerator 4 is calculated.

The cooling water outlet temperature T _{CD_out} and the condensation temperature T _Ce are used for the diagnosis of the condenser 5. Since it is difficult to measure the condensation temperature T _Ce by installing a temperature sensor near the cooling water pipe in the condenser 5, a condenser refrigerant temperature sensor 19 is installed and the measured value is corrected as necessary to condense. _{Let the} temperature be T Ce.

A cooling water pipe passes through the condenser 5, and when the inside of the cooling water pipe becomes dirty, the value of the condenser LTD becomes larger than the normal value. The evaporator LTD is calculated by the following formula (8).

Further, as another method for determining the performance of the condenser 5, the value of KAc represented by the following formula (9) may be used. If the heat transfer performance deteriorates due to dirt on the cooling water pipe or the like, the KAc value decreases.

Further, as another means for diagnosing the performance of the condenser 5, the temperature efficiency η _C represented by the following formula (10) may be used for evaluation.

In the above formulas (8) to (10), the performance of the condenser 5 may be diagnosed using any one of these formulas, or all of them may be used. By using all of them, more accurate diagnosis becomes possible.

If it is possible to measure the cooling water temperature between the outlet of the absorber 2 and the inlet of the condenser 5, the cooling water intermediate temperature T _{CD_mid} is defined as the cooling water temperature in the above equations (8) to (10). The value is calculated using _{T CD_mid} instead of the water inlet temperature T _{CD_in.} By using the cooling water intermediate temperature T _{CD_mid} , more accurate diagnosis becomes possible.

The performance of the low temperature heat exchanger 6 is diagnosed by _{the temperature efficiency η lLX of the low temperature side fluid.} The temperature of the low temperature heat exchanger rare solution outlet temperature sensor 28 is _{defined as the low temperature heat exchanger rare solution outlet temperature T sLXwo,} and the temperature of the low temperature heat exchanger concentrated solution inlet temperature sensor 26 is _defined as the low temperature heat exchanger concentrated solution inlet temperature T sLXsi. The temperature of the absorber outlet temperature sensor 16 is _{defined as the absorber outlet temperature T sAo,} and the temperature efficiency η _lLX of the low temperature side fluid is calculated from these values by the following equation (11).

Further, the performance of the low temperature heat exchanger 6 may be diagnosed by _{the temperature efficiency η hLX of the high temperature side fluid.} In this case, the temperature of the low temperature heat exchanger concentrated solution outlet temperature sensor 27 is set to the low temperature heat exchanger concentrated solution outlet temperature T _{sLXso , and η hLX} is calculated using the following equation (12).

If the pipe is punctured or crystals are deposited inside the pipe, the temperature efficiency will decrease. Therefore, the performance of the heat exchanger can be diagnosed with temperature efficiency.

The performance of the high temperature heat exchanger 7 is diagnosed by _{the temperature efficiency η hHX of the low temperature side fluid.} The temperature of the high temperature heat exchanger rare solution outlet temperature sensor 24 is set to the high temperature heat exchanger rare solution outlet temperature T _sHXwo , the temperature of the high temperature regenerator outlet temperature sensor 22 is set to the high temperature regenerator outlet temperature T _sFBo , and the high temperature heat exchanger rare solution. The temperature of the inlet temperature sensor 23 is set to the high temperature heat exchanger rare solution inlet temperature T _{sHXwi , and η lHX} is calculated using the following formula (13).

Further, the performance of the high temperature heat exchanger 7 may be diagnosed by _{the temperature efficiency η hHX of the high temperature side fluid.} In this case, the temperature of the high temperature heat exchanger concentrated solution outlet temperature sensor 25 is set to the high temperature heat exchanger concentrated solution outlet temperature T _{sHXso , and η hHX} is calculated using the following formula (14).

When a fuel (heavy oil, etc.) that generates soot or the like during combustion is used as the heating source of the heating unit 8, the flue is contaminated and the heat of the heating unit 8 is difficult to be transferred to the high temperature regenerator 3. The efficiency of the absorption chiller is reduced. Dirty flue includes a high-temperature regenerator temperature T _HG measured by high-temperature regenerator temperature sensor 17, by the exhaust gas temperature T _EXG measured by the exhaust gas temperature sensor 18, the high temperature is calculated using the following equation (15) Evaluate by vessel LTD.

In this embodiment, the absorption chiller in the case of double effect has been described, but it may be used in other absorption chillers such as single effect and triple effect. In that case, the temperature sensor is increased or decreased according to the components.

By using these mathematical formulas, the state of each component can be diagnosed.

The diagnosis of each component can be made by a numerical value called an abnormality degree, in addition to the judgment of how far the measured value is from the normal value at a certain refrigerating capacity value.

FIG. 6 is a graph showing an example of how to obtain the degree of abnormality. The horizontal axis represents the ratio of refrigerating capacity to the rated refrigerating capacity, and the vertical axis represents the condenser LTD.

In this figure, the normal value (solid line) of the condenser LTD and the measured value (measured value) of the condenser LTD when the ratio of the refrigerating capacity to the rated refrigerating capacity is 0.8 are shown. For the measured value, calculate the formula of the predicted approximate line (broken line) for each refrigerating capacity. Then, the value of the condenser LTD when the ratio of the refrigerating capacity to the rating is 1 (rated refrigerating capacity) is predicted. _Assuming that the predicted _{value of the condenser LTD is C pre_LTD} and the value of the normal value of the condenser LTD is C nor_LTD, the abnormality degree C _{ab_LTD} of the condenser LTD is defined by any of the following equations (16) to (18). NS.

By converting to the rated refrigerating capacity, it is possible to make a comparison over time.

The formula of the prediction approximation line can be calculated from the correspondence between the measured values by actually measuring the fluctuating condenser LTD and the refrigerating capacity. In addition, it is desirable to record the degree of abnormality in a recording device or the like over time. Recording changes over time is synonymous with "managing in chronological order."

FIG. 7 is a graph showing the change with time of the degree of abnormality. The horizontal axis is the date when the operation is continued, and the vertical axis is the degree of abnormality.

As shown in this figure, if the operation is continued for a certain period of time, the degree of abnormality may increase. When the degree of abnormality exceeds a preset threshold value, or when the degree of abnormality is rapidly increasing, an alert (alarm) or the like is displayed. If the degree of abnormality is rapidly increasing, it is possible to take countermeasures before the device breaks down by knowing the increasing tendency in advance.

Similar to the condenser, the components other than the condenser 5 are also diagnosed by predicting the value at the rated refrigerating capacity and calculating the degree of abnormality for each component.

FIG. 8 is a flowchart showing a calculation process of the degree of abnormality illustrated in FIG.

In FIG. 8, the measured value (measured value) of the index (condenser LTD in the example of FIG. 6) under the operating conditions is calculated for each component (S11). Next, for each component, the predicted value of the index in the rating is calculated (S12). Then, the degree of abnormality in the rating is calculated for each component (S13).

As a result, the graph illustrated in FIG. 6 can be displayed.

Further, for each component, the degree of abnormality in the rating is compared with the threshold value (S14).

FIG. 7 is an example of accumulating the abnormality degree data obtained by the step of FIG. 8 and outputting it as a graph from the past to the present.

This embodiment is an example of a high-efficiency dual-effect absorption chiller.

FIG. 9 shows the configuration of an absorption chiller with higher efficiency than that of Example 1 (FIG. 1).

The difference from FIG. 1 in FIG. 9 is that the drain heat exchanger 9 and the exhaust gas heat exchanger 10 are provided. As a result, the recovery rate of the input heat is improved, so that the fuel of the heating unit 8 can be saved.

The performance of each heat exchanger is diagnosed by calculating the temperature efficiency as in the first embodiment.

The performance of the drain heat exchanger 9 is diagnosed by _{the temperature efficiency η lDX of the low temperature side fluid.} The drain heat exchanger rare solution outlet temperature sensor 30 is set to the drain heat exchanger rare solution outlet temperature T _sDXo , the absorber outlet temperature sensor 16 is set to the absorber outlet temperature T _sAo , and the low temperature regenerator refrigerant temperature sensor 20 is set to the low temperature regenerator refrigerant. _{Let the} temperature T _{LGd, and calculate the temperature efficiency η lDX} of the low temperature side fluid from these values by the following formula (19).

The performance of the drain heat exchanger 9 may be diagnosed by _{the temperature efficiency η hDX of the high temperature side fluid.} In this case, the drain heat exchanger drain outlet temperature sensor 31 is set to the drain heat exchanger drain outlet temperature _TrDXo, and the temperature efficiency η _hDX of the high temperature side fluid is calculated by the following formula (20).

The performance of the exhaust gas heat exchanger 10 is also diagnosed with temperature efficiency in the same manner as other heat exchangers. The exhaust gas heat exchanger rare solution outlet temperature sensor 29 is set to the exhaust gas heat exchanger rare solution outlet temperature T _sEXo , the exhaust gas temperature sensor 18 is set to the exhaust gas temperature T _EXG , and the high temperature heat exchanger rare solution inlet temperature sensor 23 is set to the high temperature heat exchanger inlet. As the temperature T _{sHXwi , the temperature efficiency η lEX} of the low temperature side fluid is calculated and diagnosed using the following formula (21).

The exhaust gas temperature on the outlet side of the exhaust gas heat exchanger 10 may be measured, and the temperature efficiency η _hEX on the high temperature side may be calculated.

If the pipe is punctured or crystals are deposited inside the pipe, the temperature efficiency will decrease. Therefore, the performance of the heat exchanger can be diagnosed with temperature efficiency. Other components are diagnosed in the same manner as in Example 1.

Hereinafter, an example of the output in the performance diagnosis device of the absorption chillers of Examples 1 and 2 will be described.

FIG. 10A shows an example of a part of the measurement data 50 of FIG. 2 and a display screen of the performance index value.

In this figure, the rated values and current values of refrigerating capacity, efficiency, chilled water outlet temperature and cooling water outlet temperature are displayed. In addition, as the state of the refrigerator, a warning regarding the condenser is displayed.

FIG. 10B shows an example of a second screen for displaying detailed information such as the degree of abnormality of the refrigerator.

By displaying as shown in this figure, it is possible to provide necessary information without being restricted by the size of the screen. Similar to this figure, it is possible to switch between the third screen and the fourth screen as needed.

In the display example of FIG. 10B, since the degree of abnormality of the condenser is increasing, an alert (alarm) is displayed for the condenser. The state of each component may be displayed in words such as normal / attention / abnormality, or the degree of abnormality and its threshold value may be displayed.

Further, the configuration diagram as shown in FIGS. 1 and 9 may be simplified and displayed, and the temperature or the like may be displayed at each position in the drawing. Displaying as a configuration diagram has the advantage of being easier to understand intuitively than displaying only numerical values.

According to the present invention, when the efficiency of the absorption chiller changes, it is possible to identify the location where the defect occurs.

1: Evaporator, 2: Absorber, 3: High temperature regenerator, 4: Low temperature regenerator, 5: Condenser, 6: Low temperature heat exchanger, 7: High temperature heat exchanger, 8: Heating part, 9: Drain heat Exchanger, 10: Exhaust heat exchanger, 11: Cold water inlet temperature sensor, 12: Cold water outlet temperature sensor, 13: Evaporator refrigerant temperature sensor, 14: Cooling water inlet temperature sensor, 15: Cooling water outlet temperature sensor, 16: Absorber outlet temperature sensor, 17: high temperature regenerator temperature sensor, 18: exhaust gas temperature sensor, 19: condenser refrigerant temperature sensor, 20: low temperature regenerator refrigerant temperature sensor, 21: low temperature regenerator solution outlet temperature sensor, 22: high temperature Regenerator outlet temperature sensor, 23: high temperature heat exchanger rare solution inlet temperature sensor, 24: high temperature heat exchanger rare solution outlet temperature sensor, 25: high temperature heat exchanger concentrated solution outlet temperature sensor, 26: low temperature heat exchanger concentrated solution Inlet temperature sensor, 27: Low temperature heat exchanger concentrated solution outlet temperature sensor, 28: Low temperature heat exchanger rare solution outlet temperature sensor, 29: Exhaust heat exchanger rare solution outlet temperature sensor, 30: Drain heat exchanger rare solution outlet temperature Sensor, 31: Drain heat exchanger Drain outlet temperature sensor, 40: Refrigerator pump, 41: Solution pump, 42: Solution spray pump, 50: Measurement data, 51: Computational device, 60: Cold water flow sensor, 61: Cooling water flow rate Sensor, S1: Efficiency calculation unit, S2: Performance determination unit, S3: Element diagnosis unit, S4: Output unit.

Claims (7)

The efficiency calculation unit that calculates the efficiency of the absorption chiller,
A performance determination unit that determines whether or not the efficiency of the absorption chiller is normal,
In a device for diagnosing the performance of the absorption chiller, including an element diagnosis unit for calculating the performance of each component of the absorption chiller.
When the performance determination unit determines that the efficiency of the absorption chiller is normal, the process is terminated.
When the performance determination unit determines that the efficiency of the absorption chiller deviates from a predetermined range,
The element diagnosis unit diagnoses the measured value of any one or more of the plurality of components of the absorption chiller, and any of the measured values is within a predetermined range for the index. A performance diagnostic device for an absorption chiller, characterized in that when it deviates, it is determined that there is an abnormality in the component. In the performance diagnostic apparatus of the absorption chiller according to claim 1,
A performance diagnostic apparatus for an absorption chiller, wherein the components include an evaporator, a condenser, a solution heat exchanger, a regenerator and an absorber for the absorption chiller. In the performance diagnostic apparatus of the absorption chiller according to claim 1,
A performance diagnostic device for an absorption chiller, characterized in that when it is determined that there is an abnormality in the component, the content is output. In the performance diagnostic apparatus of the absorption chiller according to claim 1,
The element diagnosis unit calculates an equation of a prediction approximation line showing the relationship between the measured value and the actually measured refrigerating capacity, calculates the predicted value of the index related to the measured value corresponding to the rated refrigerating capacity, and obtains the predicted value. A performance diagnostic device for an absorption chiller, characterized in that a normal value of an index is compared with the predicted value. In the performance diagnostic apparatus of the absorption chiller according to claim 4,
The element diagnosis unit calculates the degree of abnormality, which is the difference between the normal value and the predicted value corresponding to the rated refrigerating capacity, and manages the performance of the absorption chiller in chronological order. Device. In the performance diagnostic apparatus of the absorption chiller according to claim 5.
The element diagnosis unit indicates an abnormality when the degree of abnormality exceeds a predetermined threshold value or when the rate of increase of the degree of abnormality is larger than a predetermined value. A performance diagnostic device for an absorption chiller, characterized in that it outputs an alarm about. In a method of diagnosing the performance of an absorption chiller using an arithmetic unit having an efficiency calculation unit, a performance judgment unit, and an element diagnosis unit.
The first step in which the efficiency calculation unit calculates the efficiency of the absorption chiller, and
A second step in which the performance determination unit determines whether or not the efficiency of the absorption chiller is normal, and
It said element diagnostic unit, viewed contains a third step of calculating the performance of each component of the absorption chiller,
When it is determined in the second step that the efficiency of the absorption chiller is normal, the process is terminated.
When it is determined in the second step that the efficiency of the absorption chiller deviates from a predetermined range,
In the third step, the measured value of any one or more of the plurality of components of the absorption chiller is diagnosed, and any of the measured values is predetermined for the index. A method for diagnosing the performance of an absorption chiller, which comprises determining that an abnormality is found in the component when it deviates from the range.

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