JP4231024B2 - Absorption diagnosis method and apparatus for absorption refrigerator - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a novel absorption refrigeration machine abnormality diagnosis method and apparatus for detecting deterioration of heat transfer characteristics or leakage of fluid flowing therein.

  As a conventional detection method, a method of visually inspecting the generation of water or bubbles by applying water pressure to a heat transfer tube or applying air pressure to a tube submerged in water is generally used.

  However, with this method, initial defects at the time of production can be found, but damage to the pipe due to aging during use, etc., cannot be found. Further, since a long time is required for the inspection, there is a problem that work efficiency is low. Therefore, in Patent Document 1, as a method for detecting leakage during operation of a device, a method is described in which a plurality of acoustic sensors are attached in the vicinity of a heat transfer tube and leakage occurrence is detected from a change in an acoustic signal at the time of leakage. . In Patent Documents 2 and 3, the undetermined coefficient of the pressure drop model in the gas pipeline is determined to be the minimum based on the measured value of the pressure diameter, and when the coefficient exceeds a predetermined value, leakage occurs. The method of judging is shown.

JP 7-248274 A JP-A-1-109236 JP-A-1-201132

  However, in the above-described conventional technology, there is a case where an acoustic signal cannot always be accurately received depending on the mounting position of the acoustic sensor. Moreover, in order to apply to the apparatus or plant which has several heat exchangers, it is necessary to newly install an acoustic sensor with respect to each heat exchanger.

  Further, as described in the above prior art, when the target device handles a high-pressure fluid (steam) like a boiler, leakage detection by an acoustic sensor is possible. However, when the pressure difference between the inside and outside of the heat transfer tube is small, it is often difficult to capture the presence or absence of leakage as a change in acoustic (vibration) data. Further, in leak detection of a gas pipeline, leak detection under specific conditions such as temperature is not shown.

  The object of the present invention is to reduce the number of measuring equipment to which a sensor such as an acoustic sensor is newly added, to be hardly affected by the installation position of the sensor, and to perform heat transfer of the heat transfer tube even when the pressure difference inside and outside the heat transfer tube is small. An object of the present invention is to provide an abnormality diagnosis method and apparatus for detecting an abnormality of an absorption refrigerator capable of detecting deterioration of characteristics or leakage of fluid in a heat transfer tube.

  An abnormality diagnosis method for an absorption chiller according to the present invention includes a state estimation function that simulates a heat transfer characteristic of a heat transfer tube by a physical formula and estimates a non-measured state quantity from a process value, and the state estimation function. Comparing the estimated value of the state quantity with the estimated value in the normal state, it is composed of an abnormality determination function for detecting deterioration of heat transfer characteristics or leakage of fluid flowing therein, and is characterized by the following: It has a requirement.

(A) At least in the model so that the difference between the calculated fluid temperature calculated by the heat transfer model simulating the heat transfer characteristics including the unsteady state with a physical formula and the corresponding measured value (fluid temperature) is reduced. Adjust the heat transfer characteristic parameters that have been set.
(B) The deterioration of the heat transfer characteristics of the heat transfer tube or the leakage of the fluid is detected using the difference between the calculated fluid temperature value calculated by the adjusted model and the corresponding measured value (fluid temperature) as an index.
( C) Degradation of heat transfer characteristics of heat transfer tubes or fluid leakage using as an index the difference between the calculated value of heat transfer characteristic parameters calculated by inputting measured values based on the model and the heat transfer characteristic parameter setting value of the adjusted model Is detected. And said (b) and (c) are comprised independently with respect to (a).

The abnormality diagnosis method for an absorption refrigerator according to the present invention includes a temperature calculation calculation means for calculating a fluid temperature by a heat transfer model simulated using heat transfer characteristics, and the fluid temperature obtained by the calculation is actually measured. It is those that can be more practiced abnormality diagnosis apparatus for the heat transfer tube and having a leakage calculation means for calculating a deterioration or leakage of fluid heat transfer characteristics of the heat transfer tubes the difference as an indication of the fluid temperature, further described Parameter adjusting means.

The present invention comprises a regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, a low-temperature regenerator that cools the water vapor, and the condenser. An evaporator that evaporates the water that is generated to generate cold water as a heat medium; the aqueous solution that absorbs water from the evaporator in an aqueous solution containing a high-concentration hygroscopic compound and the cooling water from the condenser; In an abnormality diagnosis method for an absorption refrigeration machine comprising an absorber to be cooled and a heat exchanger for exchanging heat when returning the aqueous solution from the absorber to the high-temperature regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices Calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe according to the actually measured temperature;
Heat transfer of the pipe using as an index the difference between the temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured at a position corresponding to the temperature obtained by the calculation having a step of determining the presence or absence of leakage of the heat medium body based on the size of the extent or the difference of the degradation characteristics,
Further, the temperature obtained by the calculation, and the temperature of the heat medium flowing in the pipe actually measured in a normal state of the absorption refrigerator at a position corresponding to the temperature obtained by the calculation. The heat transfer characteristic parameter is adjusted by adjusting the heat transfer coefficient, the heat transfer area and the product of the heat transfer coefficient and the heat transfer area set in the heat transfer model so that the difference between Obtaining a set value; and
Degree of deterioration of the heat transfer characteristics of the pipe or the difference using the difference between the temperature calculated by the heat transfer model using the adjusted heat transfer characteristic parameter setting value and the actually measured temperature as an index based on the size of it and a step of determining the presence or absence of leakage of the heat medium body,
And calculating a heat transfer characteristic parameter calculation value by calculating the heat transfer characteristic parameter based on the heat transfer model and the actually measured temperature;
Determining the presence or absence of leakage of the heat medium body based on the size of the extent or the difference of the degradation of heat transfer characteristics of the pipe a difference between the heat transfer characteristic parameter setting value and the heat transfer characteristic parameter calculated value as an index And a step of performing.

The present invention also provides a regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and heats the water by evaporating water from the condenser. An evaporator for generating cold water of the medium, and the aqueous solution is absorbed by the aqueous solution containing the hygroscopic compound having a high concentration, and the aqueous solution is cooled by the cooling water exiting the condenser and cooled by a cooling tower. In an abnormality diagnosis apparatus for an absorption refrigeration machine equipped with each device of a heat exchanger that exchanges heat when returning the aqueous solution from the absorber and the aqueous solution returned from the absorber to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices On the other hand, temperature calculation means for calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe by the actually measured temperature;
Wherein said temperature obtained by the calculation, the pipe of the heat transfer the difference between the temperature of the heat medium flowing through said calculations the pipe that is actually measured by the position corresponding to the temperature determined by the index and having an abnormality determination means for determining the presence or absence of leakage of the heat medium body based on the size of the extent or the difference of the degradation of characteristics.

Furthermore, the abnormality diagnosis apparatus for the absorption type refrigerator of the present invention, said one equipment heat transfer model and heat transfer model simulating the heat transfer characteristics of the pipe for circulating the heat medium in one of the devices Temperature calculating means for calculating by calculation the temperature of the other side of the heating medium of the device flowing in the pipe by the temperature actually measured on one side of the inlet and outlet of the heating medium flowing through the device as the target of;
The temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured in a normal state of the absorption chiller at a position corresponding to the temperature obtained by the calculation. Heat transfer characteristic parameter setting value by adjusting the heat transfer characteristic parameter set to any one of the heat transfer coefficient, heat transfer area and product of heat transfer coefficient and heat transfer area set in the heat transfer model so as to reduce the difference Parameter adjustment means for obtaining
Degree of deterioration of the heat transfer characteristics of the pipe or the difference using the difference between the temperature calculated by the heat transfer model using the adjusted heat transfer characteristic parameter setting value and the actually measured temperature as an index to have an abnormality determining means for determining the presence or absence of leakage of the heat medium body based on the size,
Or a calculation means for calculating the heat transfer characteristic parameter based on the heat transfer model and the actually measured temperature to obtain a heat transfer characteristic parameter calculation value;
Determining the presence or absence of leakage of the heat medium body based on the size of the extent or the difference of the degradation of heat transfer characteristics of the pipe a difference between the heat transfer characteristic parameter setting value and the heat transfer characteristic parameter calculated value as an index And an abnormality determination unit that performs the above-described abnormality determination.

  As described above, the present invention has design data estimation means for estimating design data or physical / chemical characteristic values related to input / output characteristics of plant components from measured values of plant process quantities. Also equipped with a plant model that uses model parameters determined by the design data estimation means, and a manipulated variable determination means using this model, which can accurately detect heat transfer performance degradation and fluid leakage even during non-stationary conditions It is.

The number of measuring equipment to which a sensor such as an acoustic sensor is newly added is reduced, and the heat transfer characteristics of the heat transfer tube are deteriorated or heat transfer even when the pressure difference between the inside and outside of the heat transfer tube is small due to the influence of the sensor installation position. abnormality diagnosis method of the intake Osamushiki refrigerator that can automatically detect the leakage of the fluid in the tube and can be obtained those devices. In addition, heat transfer performance deterioration and fluid leakage can be detected with high accuracy even in an unsteady state.

  The present embodiment is intended for an absorption refrigerator. The operation principle of the absorption chiller 500 will be described with reference to FIG. The absorption refrigerator 500 mainly includes an evaporator 510, an absorber 520, a condenser 530, a regenerator 540, heat exchangers 550 and 555, and fluid pumps 560 and 565. The refrigerator of this example uses a lithium bromide solution as an absorbing solution and water as a refrigerant.

  In the regenerator 540, the aqueous solution of lithium bromide having a reduced concentration by absorbing water as a refrigerant is heated to evaporate the water in the solution and concentrate the solution. The high temperature exhaust gas 410 from the turbine 404 is used as this heating source. Heat exchange is performed between the turbine exhaust gas 410 and the high-concentration lithium bromide aqueous solution to heat the lithium bromide aqueous solution. The water evaporated in the regenerator 540 flows to the condenser 530, is concentrated by heating, and the lithium bromide aqueous solution whose temperature has been increased decreases the temperature through the high temperature heat exchanger 550 and the low temperature heat exchanger 555, and the absorber 520 It is sprayed in.

  The condenser 530 condenses the steam generated in the regenerator 540 by heat exchange with the cooling water 704 and returns it to water (liquid). The condensed water is scattered in the evaporator 510. A cold water pipe is disposed in the evaporator 510, and the sprayed water takes heat from the cold water pipe and evaporates to become steam again. As a result, the temperature of the chilled water in the chilled water pipe is lowered and supplied to the chilled water demand 600 such as air conditioner as about 7 ° C. water. The water that has not evaporated once accumulates in the lower part of the evaporator 510 and is again sprayed into the container from the upper part of the evaporator 510 by the refrigerant circulation pump 565.

  The evaporated vapor is absorbed in contact with the high-concentration lithium bromide aqueous solution sprayed into the absorber 520. As the vapor is absorbed, the pressure in the absorber 520 decreases. Accordingly, the pressure in the evaporator 510 connected to the absorber 520 is also reduced, so that water as a refrigerant evaporates at a low temperature in the evaporator 510.

  Since the lithium bromide aqueous solution absorbs vapor more easily as the temperature is lower, the lithium bromide aqueous solution is cooled by the cooling water 704 in the absorber 520. Thereafter, the cooling water 704 condenses the vapor in the condenser 530 as described above, and the temperature further rises. Therefore, the cooling water 704 is cooled in the cooling tower 700 and returned to the absorber 520 again. The lithium bromide aqueous solution whose concentration has been reduced by the absorber 520 is heated by the low temperature heat exchanger 555 and the high temperature heat exchanger 550 and returned to the regenerator 540. The absorption refrigerator 500 repeats the above cycle to generate cold.

  In this example, as shown in FIG. 1, the cogeneration system is configured in combination with the gas turbine power generation system 450, so the heat source of the absorption chiller 500 uses the exhaust gas 410 from the gas turbine system 450. Yes. However, when the turbine is stopped for some reason, the exhaust chiller 500 cannot be operated because the exhaust gas 410 as a heat source cannot be received. Therefore, the regenerator 540 of the absorption chiller 500 is provided with a burner 570 serving as an alternative heat source. The gas turbine power generation system sucks and compresses air with the compressor 400 and sends the compressed air to the combustor 402. The combustor 402 combusts the fuel supplied by operating the fuel control valve 406. The combustion gas rotates the turbine 404 in the process of expanding, and rotates the generator 408 with the rotational force to obtain an electrical output.

  The absorption chiller 500 includes an evaporator 510, an absorber 520, a regenerator 540, a condenser 530, a low-temperature heat exchanger 555, and a high-temperature heat exchanger 550. Moreover, since the refrigerator produces cold water by heat transfer accompanying the evaporation of water (refrigerant) as described above, it operates at a low pressure below atmospheric pressure. Therefore, even if a hole is formed in the heat transfer tube, the degree of internal vacuum is reduced (the internal pressure increases and approaches atmospheric pressure), and the internal fluid is not ejected. Further, the cold water 504 and the cooling water 704 are also slightly pressurized by the water pump. Therefore, it is difficult to detect a leak by a change in sound at the time of the leak. In addition, since the cold water 504 and the cooling water 704 flow through a wide range such as an air conditioner and a cooling tower outside the refrigerator by piping, when applying an acoustic leak detection method, a large number of sensors are installed along the piping over a long distance. It is necessary to install, and practically difficult to apply.

  In this example, detection of leakage of the cooling water 704 will be described as an example. FIG. 2 shows a portion relating to the cooling water system. The cooling water 704 flows from the absorber 520 through the condenser 530 and is heated. After that, it is sent to the cooling tower 700 by the circulation pump 720 via the tank 760, cooled, and circulated back to the absorber 520 again. Since the cooling tower 700 is cooled by heat radiation to the outside air, the amount of cooling water slightly decreases even in a normal state due to scattering and evaporation of the cooling water to the outside. When the water level in the tank 760 falls below a certain set value, makeup water 770 is supplied to compensate for the decrease in cooling water.

  The cooling water circulation pump 720 operates in conjunction with the operation of the refrigerator 500. Circulation pump 720 is always at rated operation. Although the cooling water flow rate can be adjusted by the cooling water amount adjusting valve 710, the opening degree of the adjusting valve 710 is normally kept at the initially set opening degree. In medium and small-sized refrigerators, the cooling water flow rate is not normally measured, and changes in the cooling water flow rate cannot be monitored directly. As the measurement data regarding the cooling water, the temperature sensor 750 includes the cooling water temperature (TC1) at the inlet of the absorber 520, the cooling water temperature (TC3) at the outlet of the absorbed 520, and the cooling water temperature (TC2) at the outlet of the condenser 530, respectively. , 740 and 730.

  As the information on the refrigerator 500 side, the solution temperature (Ta) at the outlet of the absorber 520 and the refrigerant temperature (Tw) at the outlet of the condenser 530 are measured by temperature sensors 521 and 531, respectively. The coolant flow rate G1 [kg / s] is estimated from the rated output of the circulation pump 720 and the opening of the control valve 710. Or the value measured at the time of installation of a refrigerator, etc. can also be used. As shown in FIG. 2, if the cooling water leaks by ΔG [kg / s] between the cooling tower 700 and the absorber 520, the amount of cooling water flowing in the absorber 520 and the condenser 530 is actually larger than G1. Less G2 [kg / s] (G2 = G1-ΔG). In addition, the amount of cooling water may be reduced even if the flow path in the pipe is blocked due to corrosion of the cooling water pipe or mixing of foreign matter from the outside.

  The detection method of the present invention will be described below with respect to this cooling water amount reduction. First, a conventional detection method will be described. Conventionally, a method has been used in which an upper limit value is provided for the coolant outlet temperature and this is used as an abnormality determination threshold value. Since the absorption refrigerator controls the amount of heat input to the regenerator 540 in order to control the output (cold water temperature), the temperatures in the absorber 520 and the condenser 530 change accordingly. That is, the cooling water outlet temperature changes even during normal operation (FIG. 3). In addition, the cooling water inlet temperature may change, and the outlet temperature also changes in this case.

  In the conventional method, the upper limit value is set based on the maximum value of the cooling water outlet temperature at the normal time. In this case, for example, if an abnormality occurs when the cooling water outlet temperature is low (point A in FIG. 3) and the temperature rises, the abnormality cannot be detected if the upper limit (abnormality determination threshold) is not reached. Therefore, the discovery of an abnormality may be delayed.

  In contrast, in the present invention, a decrease in the amount of cooling water is detected by the following method. FIG. 4 shows a basic configuration in the present embodiment. FIG. 4 describes the absorber 520, and the following description mainly describes the absorber. However, the absorber 520 can be applied to the condenser 530 as well. The absorber model 800 models the heat transfer characteristics of the absorber 520 with the equations (1) to (3).

Where V is the heat transfer tube internal volume [m ³ ], ρ is the cooling water density [m ³ / kg], G is the cooling water flow rate [kg / s], H is the cooling water enthalpy [kJ / kg], and A is Heat transfer area [m ² ], α is the heat transfer coefficient [kW / m ² · K], T is the temperature [° C], C is the heat transfer tube specific heat [kJ / kg · K], M is the heat transfer tube mass [kg] , T is time [s], the suffix i is the inlet position, o is the outlet position, m is the heat transfer tube, f is the cooling water side, r is the heat transfer tube outside, and e is the heat transfer tube exterior. Equation (3) is an equation for calculating the average temperature of the cooling water, and ε is an average coefficient (0 ≦ ε ≦ 1). For the absorber 520, G = G1, Ti = TC1, To = TC3, and Te = Ta, and for the condenser 530, G = G1, Ti = TC3, To = TC2, and Te = Tw. A, V, C, and M use design values of the respective heat exchangers, and H can be obtained as a function of the temperature T.

The heat transfer coefficient α is a state parameter that cannot be directly measured. The heat transfer coefficient estimation function 802 estimates the heat transfer coefficient α from the equations (4) and (5) based on the model equations (1) to (3). Note that there are two heat transfer coefficients α _f and α _r on the inner surface side and the outer surface side of the heat transfer tube. Here, α _f is set to a known value and α _r is estimated.

In advance, it is necessary to match the characteristics of the absorber model 800 with the actual machine characteristics. Model characteristic adjustment is carried out in the model adjustment function 80 1. The function of the model adjustment function 80 1 will be described. In a normal state, measured values of the cooling water flow rate G1, the cooling water inlet temperature TC1, and the solution temperature Te in the absorber are input to the absorber model 800 to calculate the cooling water outlet temperature TC3cal. Calculate the difference between TC3cal and cooling water outlet temperature measured value TC3, and change the value of heat transfer coefficient setting value α _r or α _f of absorber model 800 in such a direction that the difference between the two becomes smaller, again cooling water outlet temperature TC3cal Is compared with the measured value TC3. This operation is repeated until the difference between TC3cal and TC3 falls below the allowable value ΔTC3.

FIG. 5 shows an estimation result of the absorber heat transfer coefficient when the cooling water amount G1 is intentionally changed assuming that the cooling water amount is reduced for some reason. When estimating the heat transfer coefficient α _r using the equations (4) and (5), it was naturally assumed that there was no change in the cooling water amount G1. In this example, since the heat transfer coefficients α _f and α _r in the model equations (1) and (2) are set as constants regardless of the operation state, the model set value of the heat transfer coefficient indicated by the broken line in FIG. 5 is constant. It is. However, the present invention does not depend on the model heat transfer coefficient setting method, and the set value is not necessarily a constant value. For example, the heat transfer coefficient may be set as a function of the cooling water amount.

The estimated value almost coincides with the model set value from 0 to t1 when the cooling water amount is constant. When the amount of cooling water is reduced from G1 to G2 at time t1, the estimated value of the heat transfer rate increases from alpha _{r 1} to alpha _{r 2.} When the amount of cooling water is returned to G1 from time t2, the estimated value decreases to near α _r 1. Therefore, if the cooling water amount is normal (G1), the estimated value of the heat transfer coefficient α _r matches the model set value within a certain error range, but if the cooling water amount decreases (G2), the estimated value and the model set value And the deviation becomes larger.
In the determination function 803, a decrease in the cooling water amount is determined by the following method. If the standard deviation of the estimated value with respect to the normal model setting value is σ, and the deviation between the estimated value and the model setting value is larger than n times the standard deviation σ (for example, n = 3), it is determined that the cooling water amount is abnormal. In FIG. 5, the amount of cooling water is determined to be abnormal at time t3.

  The abnormality determination method may be other methods. For example, when the deviation amount between the estimated value and the model setting value is larger than a certain reference value (for example, 3σ) and the state continues for a certain time or more, the abnormality is determined. It may be determined. In this way, even if a deviation temporarily increases due to noise with respect to the sensor signal or an error of the measuring instrument and a state exceeding the reference value occurs, it is not determined that there is an abnormality, and the reliability of abnormality detection is improved. In order to deal with noise and measurement errors, the measurement value may not be used as it is, but data after smoothing processing such as time average may be used, or the estimated value may be smoothed and used for abnormality determination.

  As described above, the cooling water flows through the absorber 520 and the condenser 530. When the cooling water leaks before the absorber 520, both the cooling water flowing through the absorber 520 and the condenser 530 are reduced, but when the leakage is between the absorber 520 and the condenser 530, the absorber 520 Is not affected, only the condenser 530 is affected. Therefore, if the states of the absorber 520 and the condenser 530 are monitored by the above-described method, the leaked place can be specified.

  However, depending on the refrigerator, the cooling water temperature TC3 between the absorber 520 and the condenser 530 may not be measured. In this case, the cooling water inlet temperature TC1 is obtained for the absorber 520 but the outlet temperature TC3 is not obtained. For the condenser 530, the cooling water outlet temperature TC2 is obtained, but the inlet temperature TC3 is not obtained. For this reason, both the absorber 520 and the condenser 530 cannot detect abnormality by the above-described method. Therefore, FIG. 6 shows the configuration of the detection system when TC3 is not measured. The difference from the configuration shown in FIG. 4 is that the cooling water outlet temperature of the absorber 520 is calculated by the absorber model 800, and the calculated value TC3cal is input to the condenser model 804 to estimate the heat transfer coefficient and The abnormality determination is performed only for the condenser model 804.

A method for detecting a decrease in the amount of cooling water in this case will be described below. First, using the absorber model 800 shown in the equations (1) to (3), the cooling water flow rate G1 (however, it may actually be less than G1 due to cooling water leakage, etc.), the solution temperature Te in the absorber Then, the cooling water outlet temperature TC3cal of the absorber 520 is calculated from the actually measured value of the cooling water inlet temperature TC1. For the condenser 530, the heat transfer coefficient _αr is estimated by the above-described method to determine whether or not the cooling water amount has decreased. At this time, the cooling water inlet temperature to the condenser 530 is TC3cal calculated by the absorber model.

  The condenser model 804 uses the normal data in advance so that the heat transfer coefficient value of the condenser model 804 is such that the error between the measured value TC2 of the cooling water temperature at the outlet of the condenser 530 and the calculated value TC2cal is less than the allowable value ΔTC2. Adjust. Therefore, when the heat transfer coefficient of the condenser is estimated using TC3cal calculated by the absorber model 800 in the normal state, the deviation between the estimated value and the set value of the condenser model 804 is within an error range. . When the cooling water leaks, the difference between the estimated value of the heat transfer coefficient of the condenser and the model setting value becomes large, and the leak can be detected. The determination function 803 is the same as the function described above. In this case, since TC3 is not measured, it is not possible to specify whether the leakage of the cooling water is before the absorber 520 or after the absorber 520, but it is detected that the cooling water is leaking. can do.

  As described above, according to the present invention, it is possible to detect leakage of cooling water using existing measurement information. In addition, since the heat transfer coefficient of the heat transfer tube is estimated in the present invention, if this estimated value is monitored, the heat transfer performance deteriorates due to adhesion of foreign matters to the heat transfer surface, corrosion of the heat transfer surface, or the like. It is possible to grasp this quantitatively.

  FIG. 7 shows an example of monitoring the heat transfer coefficient estimated value. The upper part of FIG. 7 displays estimated values in a relatively short time range of 2 o'clock at 1 minute intervals. In the lower row, the transition for three months is displayed as an average value for each day. If a sudden leak occurs due to a crack in the heat transfer tube, it can be confirmed on the upper monitor graph. In addition, deterioration in heat transfer performance due to dirt on the heat transfer surface often progresses gradually, so check with the lower monitor graph. In the example shown in FIG. 7, it can be seen from the lower graph that the heat transfer performance gradually decreases.

  As described above, according to the present invention, since deterioration of heat transfer performance and occurrence of leakage can be accurately evaluated, cleaning and inspection of equipment can be performed only when it is truly necessary. Therefore, unnecessary work such as excessive inspection and maintenance can be reduced. Thereby, both the owner of the equipment or the maintenance / administrator can reduce the maintenance cost.

Cogeneration system diagram of absorption refrigerator and gas turbine power generation. The block diagram showing the cooling water system of an absorption refrigerator. The figure showing the time change of a cooling water exit temperature. The block diagram of the cooling water system diagnosis of an absorption refrigerator. The figure showing the heat transfer rate estimation result at the time of cooling water amount reduction | decrease. The block diagram of the abnormality diagnosis of an absorption refrigerator. The figure showing the change of a heat transfer rate estimated value.

Explanation of symbols

500 ... Absorption refrigerator, 510 ... Evaporator, 520 ... Absorber, 530 ... Condenser, 540 ... Regenerator, 550, 555 ... Heat exchanger, 560, 565 ... Fluid pump, 800 ... Absorber model, 801 ... Model adjustment function, 802... Heat transfer coefficient estimation function, 803.

Claims (6)

A regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and evaporates water from the condenser to generate cold water of the heat medium. An evaporator that absorbs water from the evaporator into an aqueous solution containing a high concentration of the hygroscopic compound and cools the aqueous solution with the cooling water that exits the condenser and is cooled by a cooling tower; In the abnormality diagnosing method of the absorption refrigeration machine provided with each device of the heat exchanger for exchanging heat when returning the aqueous solution from the refrigerator to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices Calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe by the actually measured temperature;
Heat transfer of the pipe using as an index the difference between the temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured at a position corresponding to the temperature obtained by the calculation And determining whether or not the heat medium has leaked based on the degree of deterioration of characteristics or the magnitude of the difference. A regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and evaporates water from the condenser to generate cold water of the heat medium. An evaporator that absorbs water from the evaporator into an aqueous solution containing a high concentration of the hygroscopic compound and cools the aqueous solution with the cooling water that exits the condenser and is cooled by a cooling tower; In the abnormality diagnosing method of the absorption refrigeration machine provided with each device of the heat exchanger for exchanging heat when returning the aqueous solution from the refrigerator to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices Calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe by the actually measured temperature;
The temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured in a normal state of the absorption chiller at a position corresponding to the temperature obtained by the calculation. Heat transfer characteristic parameter setting value by adjusting the heat transfer characteristic parameter set to any one of the heat transfer coefficient, heat transfer area and product of heat transfer coefficient and heat transfer area set in the heat transfer model so as to reduce the difference The process of seeking
Degree of deterioration of the heat transfer characteristics of the pipe or the difference using the difference between the temperature calculated by the heat transfer model using the adjusted heat transfer characteristic parameter setting value and the actually measured temperature as an index And determining whether or not the heat medium has leaked based on the size of the absorption medium . A regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and evaporates water from the condenser to generate cold water of the heat medium. An evaporator that absorbs water from the evaporator into an aqueous solution containing a high concentration of the hygroscopic compound and cools the aqueous solution with the cooling water that exits the condenser and is cooled by a cooling tower; In the abnormality diagnosing method of the absorption refrigeration machine provided with each device of the heat exchanger for exchanging heat when returning the aqueous solution from the refrigerator to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices Calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe according to the actually measured temperature;
The temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured in a normal state of the absorption chiller at a position corresponding to the temperature obtained by the calculation. Heat transfer characteristic parameter setting value by adjusting the heat transfer characteristic parameter set to any one of the heat transfer coefficient, heat transfer area and product of heat transfer coefficient and heat transfer area set in the heat transfer model so as to reduce the difference The process of seeking
Calculating the heat transfer characteristic parameter based on the heat transfer model and the actually measured temperature to obtain a heat transfer characteristic parameter calculated value;
Using the difference between the calculated value of the heat transfer characteristic parameter and the set value of the heat transfer characteristic parameter as an index, the presence or absence of leakage of the heat medium is determined based on the degree of deterioration of the heat transfer characteristic of the pipe or the magnitude of the difference And a method for diagnosing an abnormality of the absorption refrigerator. A regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and evaporates water from the condenser to generate cold water of the heat medium. An evaporator that absorbs water from the evaporator into an aqueous solution containing a high concentration of the hygroscopic compound and cools the aqueous solution with the cooling water that exits the condenser and is cooled by a cooling tower; In the abnormality diagnosing device for an absorption refrigeration machine provided with each device of a heat exchanger for exchanging heat when returning the aqueous solution from the refrigerator to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices On the other hand, temperature calculation means for calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe by the actually measured temperature;
It said temperature determined by said calculation, the pipe of the heat transfer the difference between the temperature of the heat medium flowing in said measured pipe in reality at a position corresponding to the temperature obtained by the calculation as an index An abnormality diagnosing device for an absorption refrigerating machine, comprising abnormality determining means for determining the presence or absence of leakage of the heat medium based on the degree of deterioration of characteristics or the magnitude of the difference. A regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and evaporates water from the condenser to generate cold water of the heat medium. An evaporator that absorbs water from the evaporator into an aqueous solution containing a high concentration of the hygroscopic compound and cools the aqueous solution with the cooling water that exits the condenser and is cooled by a cooling tower; In the abnormality diagnosing device for an absorption refrigeration machine provided with each device of a heat exchanger for exchanging heat when returning the aqueous solution from the refrigerator to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices On the other hand, temperature calculation means for calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe by the actually measured temperature;
The temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured in a normal state of the absorption chiller at a position corresponding to the temperature obtained by the calculation. Heat transfer characteristic parameter setting value by adjusting the heat transfer characteristic parameter set to any one of the heat transfer coefficient, heat transfer area and product of heat transfer coefficient and heat transfer area set in the heat transfer model so as to reduce the difference Parameter adjustment means for obtaining
Degree of deterioration of the heat transfer characteristics of the pipe or the difference using the difference between the temperature calculated by the heat transfer model using the adjusted heat transfer characteristic parameter setting value and the actually measured temperature as an index abnormality diagnosis apparatus for an absorption refrigerator, characterized in that it comprises an abnormality determination means for determining the presence or absence of leakage of the heat medium body based on the size of the. A regenerator that heats an aqueous solution containing a hygroscopic compound with a heat medium to generate water vapor, a condenser that condenses the water vapor with cooling water of the heat medium, and evaporates water from the condenser to generate cold water of the heat medium. An evaporator that absorbs water from the evaporator into an aqueous solution containing a high concentration of the hygroscopic compound and cools the aqueous solution with the cooling water that exits the condenser and is cooled by a cooling tower; In the abnormality diagnosing device for an absorption refrigeration machine provided with each device of a heat exchanger for exchanging heat when returning the aqueous solution from the refrigerator to the regenerator,
Wherein the entrance of one of equipment the heat is subject to the heat transfer model and the heat transfer model simulating the heat transfer characteristics of the pipe for flowing the heat medium flowing through said device in the medium of the respective devices On the other hand, a temperature calculation means for calculating the other temperature of the inlet / outlet of the heat medium of the device flowing in the pipe by the actually measured temperature,
The temperature obtained by the calculation and the temperature of the heat medium flowing in the pipe actually measured in a normal state of the absorption chiller at a position corresponding to the temperature obtained by the calculation. Heat transfer characteristic parameter setting value by adjusting the heat transfer characteristic parameter set to any one of the heat transfer coefficient, heat transfer area and product of heat transfer coefficient and heat transfer area set in the heat transfer model so as to reduce the difference Adjusting means for obtaining
Calculation means for calculating the heat transfer characteristic parameter based on the heat transfer model and the actually measured temperature to obtain a heat transfer characteristic parameter calculation value;
Determining the presence or absence of leakage of the heat medium body based on the size of the extent or the difference of the degradation of heat transfer characteristics of the pipe a difference between the heat transfer characteristic parameter setting value and the heat transfer characteristic parameter calculated value as an index An abnormality diagnosing device for an absorption refrigeration machine, comprising:

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