JP3258684B2 - Abnormality detector for absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator, and more particularly, to a device for detecting an abnormality of an absorption refrigerator for detecting an abnormality of an absorber.

[0002]

2. Description of the Related Art For example, in Japanese Patent Application Laid-Open No. 1-142374, a temperature detector and a pressure detector are installed in an internal space of an evaporator, and output signals from the respective detectors are inputted. A refrigerator protection device including a setting device that outputs a refrigerator stop signal and an alarm signal when a value is reached is disclosed.

[0003]

In the above prior art, the refrigerator is, for example, an absorption refrigerator, and when an abnormality of an absorber other than the evaporator is detected, for example, the absorber is generally connected to the absorber in the same manner as the evaporator. A pressure detector is provided to detect a pressure rise at the time of occurrence of an abnormality, and INPUT is compared with a design value at 100%. For this reason, when the absorption type refrigerator is partially loaded or there is almost no load in the spring or autumn other than in summer, the abnormality of the absorber cannot be accurately detected, so that the detection of the abnormality of the refrigerator is delayed.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an absorption refrigerator having a high-temperature regenerator 4, a condenser 7, an evaporator 1, and an absorber 2 connected by piping. Chilled water temperature detectors 36 and 37 for detecting the chilled water inlet temperature and the outlet temperature of the evaporator 1, cooling water temperature detectors 40 and 41 for detecting the chilled water inlet temperature and the outlet temperature of the absorber 2, respectively, and an absorber 2, an absorbent outlet temperature detector 38 for detecting the temperature of the outlet side absorbent, and an absorbent inlet temperature detector 39 for detecting the temperature of the absorbent dispersed in the absorber 2.
And the difference between the detected temperatures of the chilled water temperature detectors 36 and 37 and 10
The chilled water load is calculated from the chilled water inlet / outlet temperature difference at the time of 0% load, and the absorber is determined from the detected temperatures of the cooling water temperature detectors 40 and 41, the absorbent outlet temperature detector 38, and the absorbent inlet temperature detector 39. calculating the actual logarithmic mean temperature difference of 2, cold water negative
Ideal log average temperature difference and actual log average temperature difference
And an abnormality detector 42 that outputs an abnormality signal by comparing the above-mentioned conditions, and an abnormality detection device for the absorption refrigerator that reliably detects the abnormality of the absorber 2 even when the absorption refrigerator is partially loaded. is there.

A concentrated liquid temperature detector 53 for detecting the temperature of the absorbent at the outlet of the low temperature regenerator 6, a condensing temperature detector 54 for detecting the condensing temperature of the condenser 7, and a chilled water inlet temperature of the evaporator 1. Temperature detector 3 for detecting the temperature of the outlet and the outlet
6, 37, an absorbent outlet temperature detector 38 for detecting the temperature of the absorbent on the outlet side of the absorber 2, a pressure detector 52 for detecting the pressure in the absorber 2, and a concentrated liquid temperature detector 53 for detection. The concentration of the concentrated liquid sprayed on the absorber 2 is calculated from the temperature of the concentrated absorbing liquid thus obtained and the condensation temperature detected by the condensation temperature detector 54, and the concentration of the concentrated liquid and the pressure detected by the pressure detector 52 are absorbed. The temperature of the concentrated absorbent to be sprayed on the absorber 2 is determined, and the temperature of the concentrated absorbent, the temperature of the absorbent on the outlet side of the absorber 2 and the temperature of the cooling water
The actual logarithmic average temperature difference of the absorber 2 is calculated from the cooling water inlet / outlet temperatures detected by 0 and 41, and the difference between the detected temperatures of the respective chilled water temperature detectors 36 and 37 and the chilled water inlet / outlet temperature difference at 100% load. And an abnormality detector that outputs an abnormality signal by comparing the ideal log average temperature difference and the actual log average temperature difference with respect to the chilled water load, and even when the absorption chiller is partially loaded. It is an object of the present invention to provide an abnormality detection device that reliably detects an abnormality of the absorber 2 before the cold water temperature changes due to the abnormality.

[0006]

[0007]

When the absorption refrigerator is in operation, the abnormality detector 42 is provided with the chilled water temperature detectors 36 and 37, the absorption liquid outlet temperature detector 38, the absorption liquid inlet temperature detector 39, and the cooling water temperature detectors 40 and 4,
1, a load is calculated from the chilled water inlet / outlet temperature difference at 100% load and the actual chilled water inlet / outlet temperature difference, and the actual logarithmic average temperature difference of the absorber 2 is calculated.
If the logarithmic average temperature difference exceeds the abnormal line of the logarithmic average temperature difference of the load at that time, the abnormality detector 42 outputs an abnormality signal to notify the abnormality of the absorber 2, so that the abnormality other than the summer season is detected. An abnormality can be detected even when the absorption refrigerator has a partial load in spring or the like, and maintenance and inspection work can be performed early on abnormality of the absorber 2.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows that the refrigerant is, for example, water and an absorbing liquid (solution).
FIG. 1 is a schematic configuration diagram of an absorption chiller / heater, which is an absorption refrigerator using a lithium bromide (LiBr) solution, wherein 1 is an evaporator,
Reference numeral 2 denotes an absorber, 3 denotes an evaporator absorber body (hereinafter referred to as a lower body) containing the evaporator 1 and the absorber 2, 4 denotes a high-temperature regenerator provided with, for example, a gas burner 5 and heated by a high-temperature heat source, 6
Is a low-temperature regenerator, 7 is a condenser, 8 is a low-temperature regenerator condenser body (hereinafter referred to as an upper body) containing the low-temperature regenerator 6 and the condenser 7, 9 is a low-temperature heat exchanger, and 10 is a high-temperature heat exchanger. , 11 to 15 are absorption liquid pipes, 16 is an absorption liquid pump, 17 and 18 are refrigerant pipes, 19 is a refrigerant circulation pipe, 20 is a refrigerant pump, 21 is a gas pipe connected to the gas burner 5, 22 is a heating amount. The control valve 23 is a cold water pipe provided with an evaporator heat exchanger 24 on the way, and each is connected to the pipe as shown in FIG.

Reference numeral 25 denotes a cooling water pipe, and an absorber heat exchanger 26 and a condenser heat exchanger 27 are provided in the cooling water pipe 25. 28 is a refrigerant bypass pipe connecting the refrigerant reservoir 29 of the evaporator 1 to the absorbent reservoir 30 of the absorber 2, 31 is an on-off valve, 32 is an absorbent bypass pipe connecting the absorbent pipe 12 and the absorber 2. , 33 is an on-off valve,
34 is a refrigerant vapor bypass pipe connecting the refrigerant pipe 17 and the absorber 2, and 35 is an on-off valve, and each of the on-off valves 31, 33,
35 is closed when supplying cold water and opened when supplying hot water.

Reference numerals 36 and 37 denote first and second temperature detectors, respectively, which are cold water inlet / outlet temperature detectors provided on the inlet side and the outlet side of the evaporator 1 of the cold water pipe 23, and 38 is an absorbing liquid pump for the absorbing liquid 11. Absorbing liquid outlet temperature detector provided on the outlet side of the above, 39 is a temperature of a high concentration absorbing liquid (hereinafter referred to as a concentrated liquid) which is provided on the absorbing liquid pipe 15 on the inlet side of the absorber 2 and which is sprayed on the absorber 2. Is a cooling water inlet temperature detector for detecting the inlet-side cooling water temperature of the absorber 2, and 41 is a cooling water outlet temperature for detecting the outlet-side cooling water temperature of the absorber 2. The detector 42 is an abnormality detector that receives a temperature signal from each of the above temperature detectors and detects an abnormality detection device of the absorber 2. The abnormality detector 42 is, for example, a control panel (shown in the drawing) of an absorption refrigerator. ) And configured with a microcomputer It has been. Reference numeral 43 denotes a notification device provided on the control panel similarly to the abnormality detector 42 and operating by inputting a signal from the abnormality detector. This notification device 43
Is composed of a display device 44 having a plurality of segment elements and a buzzer 45, for example. And the display device 4
4 is based on a signal from the abnormality detector 42, for example, ALA.
Flashes the letters RM.

Hereinafter, the configuration of the abnormality detector 42 will be described with reference to FIG.
It will be described based on. 46 is the first and second temperature detectors 3
6, 37, an absorption liquid outlet temperature detector 38, an absorption liquid inlet temperature detector 39, a cooling water inlet temperature detector 40, and a cooling water outlet temperature detector 41. An input interface for outputting to a CPU (hereinafter referred to as a CPU) 47 is a storage device (hereinafter referred to as a ROM) storing an arithmetic program and the like relating to the present invention;
49 is an output interface for inputting a signal from the CPU 46 and outputting it to the notification device 41, 50 is a signal generator (hereinafter referred to as CLOOCK) for outputting a signal every predetermined time,
Reference numeral 51 denotes a readable and erasable storage device (hereinafter referred to as a RAM) for storing the temperature detected by each temperature detector.

The ROM 48 stores a cooling water inlet temperature T.
1, the actual logarithmic average temperature difference T of the absorber 2 from the cooling water outlet temperature T2, the absorbing solution inlet temperature T3, and the absorbing solution outlet temperature T4.
calculate em

[0013]

(Equation 1)

And 1 during normal operation of the absorption refrigerator.
A program for calculating the chilled water load from the difference between the chilled water inlet temperature and the chilled water outlet temperature at the time of the 00% load and the actually detected difference between the chilled water inlet temperature and the chilled water outlet temperature. The relationship with the logarithmic average temperature difference is stored.
In FIG. 3, A is an ideal line indicating the relationship between the chilled water load and the ideal logarithmic mean temperature difference when the absorption refrigerator is operating normally, and B is an abnormal line that outputs an abnormal signal.

During the operation of supplying cold water of the absorption refrigerator, the refrigerant evaporated in the high-temperature regenerator 4 flows to the condenser 7 through the low-temperature regenerator 6 as in the conventional absorption refrigerator, and the heat exchanger is connected to the condenser. After being condensed and liquefied by exchanging heat with the cooling water flowing through 27, it flows to the evaporator 1 via the refrigerant pipe 18. Then, the refrigerant exchanges heat with water flowing through the evaporator heat exchanger 24 to evaporate, and the water flowing through the evaporator heat exchanger 24 is cooled by heat of vaporization.
Then, cold water circulates through the load. Further, the refrigerant evaporated in the evaporator 1 is absorbed by the absorbing liquid in the absorber 2. The absorption liquid whose concentration has been reduced by absorbing the refrigerant is sent to the high-temperature regenerator 4 via the low-temperature heat exchanger 9 and the high-temperature heat exchanger 10 by the operation of the absorption liquid pump 16. The absorbing liquid sent to the high-temperature regenerator 4 is heated by the burner 5 to evaporate the refrigerant, and the medium-density absorbing liquid flows through the high-temperature heat exchanger 10 to the low-temperature regenerator 6. In the low-temperature regenerator 6, the absorbing liquid is heated by the refrigerant vapor flowing from the high-temperature regenerator 10 through the refrigerant pipe 17, and the refrigerant vapor is further separated to increase the concentration. The high-concentration absorbent is cooled down through the low-temperature heat exchanger 9 and sent to the absorber 2 where it is dispersed.

As described above, abnormality detection when the absorption refrigerator is in operation will be described with reference to the flowchart of FIG. A first and a second temperature detectors 36 and 37, an absorbent outlet temperature detector 38, an absorbent inlet temperature detector 39,
Cooling water inlet temperature detector 40 and cooling water outlet temperature detector 4
1 detects the input interface 46 and C
It is temporarily stored in the RAM 51 via the PU 47. The CPU 47 reads the chilled water inlet temperature, chilled water outlet temperature, absorbing liquid outlet temperature, absorbing liquid inlet temperature, cooling water inlet temperature, and cooling water outlet temperature stored in the RAM 51 at predetermined intervals based on a signal from the CLOCK 50. At the same time, the equation 1, the program, and the relationship between the chilled water load and the logarithmic average temperature difference are read from the ROM 48. Then, the load (%) is calculated from the actual chilled water inlet / outlet temperature difference and the chilled water inlet / outlet temperature difference (5 ° C.) when the load is 100%. Here, for example, when the cold water inlet temperature is 10 ° C., the cold water outlet temperature is 7 ° C., and the temperature difference is 3 ° C., the load is 3/5 =
0.6 (60%).

The CPU 47 sets the outlet temperature of the absorbent,
The actual logarithmic average temperature difference Tem is calculated from the absorption liquid inlet temperature, the cooling water inlet temperature, the cooling water outlet temperature, and the equation (1). Here, for example, the heat exchange performance in the absorber 2 is reduced due to contamination of the absorber heat exchanger 26, and the cooling water inlet temperature is, for example, 32 ° C., the cooling water outlet temperature is, for example, 34 ° C.
When the absorption liquid inlet temperature is, for example, 54 ° C. and the absorption liquid outlet temperature is, for example, 40 ° C., the actual logarithmic average temperature difference is approximately 13 ° C.
become. Then, since this logarithmic average temperature difference is higher than the value (10 ° C.) when the load of the abnormal line is 60% shown in FIG. 3, the CPU 47 outputs an abnormal signal via the output interface 49 and outputs an abnormal signal. An abnormal signal is output from the detector 42 to the notification device 43. Then, ALARM is displayed on the display device 44 of the notification device 43, and the buzzer 45 sounds to notify the abnormality of the absorber 2.

When the load of the chilled water is, for example, 60%, the outlet temperature of the absorbent, the inlet temperature of the absorbent, the inlet temperature of the cooling water, the outlet temperature of the cooling water, and the actual logarithmic mean temperature difference Tem calculated from the above equation (1) are calculated. For example, when the temperature is 9.5 ° C. and is lower than the value (10 ° C.) on the abnormal line when the load is 60%, C
The PU 47 does not output an abnormality signal, and the notification device 43 does not notify the abnormality.

According to the above embodiment, the abnormality detector 42 calculates the actual logarithmic mean temperature difference based on the absorption liquid outlet temperature, the absorption liquid inlet temperature, the cooling water inlet temperature, and the cooling water outlet temperature according to the above equation (1). When the abnormality is detected in the absorber 2 and the logarithmic average temperature difference exceeds the previously stored abnormality line, the abnormality detector 42 outputs a signal. Also, in the case where an abnormality occurs in the absorber 2, it is possible to detect the abnormality at the partial load of the absorption chiller / heater and to cope with the early stage of the occurrence of the abnormality. As a result, the maintenance of the absorption chiller / heater can be performed. Inspection can be performed more reliably.

Hereinafter, a second embodiment of the present invention will be described. It should be noted that a configuration that is not particularly described is the same as the above-described embodiment, and a detailed description is omitted. 52 is a pressure detector for detecting the pressure in the absorber 2 and 53 is a low-temperature regenerator 6
Is a concentrated liquid temperature detector for detecting the concentrated liquid temperature at the outlet side of the condenser, and 54 is a condensation temperature detector for detecting the refrigerant condensation temperature of the condenser 7. In this embodiment, the ROM 46 of the abnormality detector 42
A formula for calculating the concentration of the concentrated liquid at the outlet side of the low-temperature regenerator 6 from the concentrated liquid temperature at the outlet side of the low-temperature regenerator 6 and the condensation temperature of the condenser 7 and absorption from the concentration of the concentrated liquid and the pressure of the absorber 2 Vessel 2
A program (calculation formula or During diagram) for obtaining the concentrated liquid spraying temperature in the above is stored. Then, the concentrated liquid temperature at the outlet side of the low-temperature regenerator 6, the refrigerant condensation temperature of the condenser 7, and the concentrated liquid spraying temperature (saturation temperature) of the absorber 2 obtained from the pressure of the absorber 2 are determined by the absorption liquid inlet temperature T 3. Instead, the actual logarithmic average temperature difference of the absorber 2 is calculated by substituting the equation 1 into the above equation, and when this value exceeds the abnormal line, the abnormality detecting device 42 outputs an abnormal signal.

As described above, the actual logarithmic mean temperature difference of the absorber 2 is obtained by using the concentrated liquid spraying temperature, so that the absorbing liquid inlet temperature is detected by the absorbing liquid inlet temperature detector 39 and the logarithmic average temperature is detected. The logarithmic average temperature difference can be calculated more accurately than when the difference is obtained. As a result, the abnormality can be detected more accurately before the abnormality causes a change in the chilled water temperature.

Further, as shown in the above embodiment, the absorber 2
Is calculated, and the ratio of the chilled water load to the logarithmic average temperature difference is calculated. For example, the chilled water load is 60%, the actual log average temperature difference is 8.4 ° C., and the ratio of the load to the log average temperature difference is 0.14 ° C./%. /%, The same effect as in the above embodiment can be obtained even when the abnormality detection device 42 outputs an abnormality signal.

Further, the actual logarithmic average temperature difference of the absorber 2 is calculated based on the cooling water inlet temperature, the cooling water outlet temperature, the absorbing liquid inlet temperature or the concentrated liquid spraying temperature and the absorbing liquid outlet temperature. Calculate the ratio to the log average temperature difference. Then, when this ratio exceeds a predetermined value, the abnormality detector 42 outputs an abnormality signal. For example, when the load is 60%, the actual log average temperature difference is 10 ° C., and the ideal log average temperature difference is 8
At ℃, the above ratio is 10/8 = 1.25, and when the ratio is equal to or more than a predetermined value (for example, 1.25), the abnormality detector 42
Outputs an abnormal signal. Further, the actual heat transmission coefficient, which is the reciprocal of the above ratio, is calculated, and this heat transmission coefficient is set to a predetermined value (for example, 8).
0%) or less, the same effect can be obtained when the abnormality detector 42 outputs an abnormality signal.

Although the above embodiment has been described based on the absorption type chiller / heater which can supply cold or hot water, the absorption type chiller which supplies only cold water may be provided with an abnormality detector similarly to the above embodiment. Thereby, the same operation and effect can be obtained.

[0025]

According to the present invention, there is provided an abnormality detecting device for an absorption refrigerator configured as in the above embodiment, in which the inlet and outlet temperatures of a chilled water of an evaporator are detected by a chilled water temperature detector, and the cooling of the absorber is performed. The water inlet and outlet temperatures are each detected by a cooling water temperature detector, the temperature of the absorbing solution at the outlet side of the absorber is detected by the absorbing solution outlet temperature detector, and the temperature of the absorbing solution sprayed on the absorber is detected by the absorbing solution inlet. Detected by the temperature detector, the abnormality detector calculates the chilled water load from the difference between the detected temperature of each chilled water temperature detector and the chilled water inlet / outlet temperature difference at the time of 100% load. The actual logarithmic average temperature difference of the absorber is calculated from the temperatures detected by the outlet temperature detector and the absorption liquid inlet temperature detector, and the ideal logarithmic average temperature difference and actual logarithmic
Compares the average temperature difference and outputs an abnormal signal.
Calculate the ideal logarithmic average temperature difference to compare the number average temperature difference.
For example, for simulation without actually performing experiments
Therefore, it can be easily calculated, and also, for example , it is possible to reliably detect the abnormality of the absorber even in the case of a partial load in an intermediate period other than summer, and as a result, the maintenance and inspection of the absorption refrigerator can be performed early. Thus, the suspension of the absorption refrigerator can be avoided.

Further, the concentration of the concentrated liquid flowing into the absorber is determined, the temperature of the concentrated liquid sprayed on the absorber is determined from the concentration and the pressure in the absorber, and the temperature of the cold water inlet / outlet, the temperature of the cooling water inlet and the outlet of the cooling water are determined. The actual logarithmic mean temperature difference of the absorber is calculated from the temperature of the absorbent at the outlet side of the absorber and the temperature of the concentrated solution sprayed on the absorber , and the difference between the detected temperature of each chilled water temperature detector and 10
Calculate chilled water load from chilled water inlet / outlet temperature difference at 0% load
The ideal logarithmic mean temperature difference and the actual log
Outputs an abnormal signal by comparing with the number average temperature difference.
Logarithmic mean temperature difference to compare the logarithmic mean temperature difference
Without actually performing an experiment etc.
In addition, the abnormality of the absorber can be more accurately detected before an abnormality occurs and a change in the chilled water temperature occurs.

[0027]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an absorption refrigerator showing one embodiment of the present invention.

FIG. 2 is a block diagram of an anomaly detector.

FIG. 3 is a relationship diagram between a load and a logarithmic average temperature difference.

FIG. 4 is a flowchart illustrating the operation of the abnormality detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Evaporator 2 Absorber 4 High temperature regenerator 6 Low temperature regenerator 9 Low temperature heat exchanger 10 High temperature heat exchanger 36 Cold water temperature detector 37 Cold water temperature detector 38 Absorbent liquid outlet temperature detector 39 Absorbent liquid inlet temperature detector 40 Cooling Water inlet temperature detector 41 Cooling water outlet temperature detector 42 Abnormality detector

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-146966 (JP, A) JP-A-3-67966 (JP, A) JP-A-61-31864 (JP, A) Hideo Obana, “ Heat Exchanger Design Handbook, 2nd Edition, Kogaku Tosho Co., Ltd., July 1977, P. 169-185 (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 49/04

Claims (2)

(57) [Claims] 1. An absorption refrigerator in which a regenerator, a condenser, an evaporator, an absorber and the like are connected by piping, a chilled water temperature detector for detecting a chilled water inlet temperature and an outlet temperature of the evaporator, and an absorber. A cooling water temperature detector that detects a cooling water inlet temperature and an outlet temperature of the cooling water, an absorbing liquid outlet temperature detector that detects a temperature of an absorbing liquid on an outlet side of the absorber, and a temperature of the absorbing liquid sprayed on the absorber. The chilled water load is calculated from the difference between the detected temperature of the absorbing liquid inlet temperature detector, the detected temperature of each chilled water temperature detector, and the chilled water inlet / outlet temperature difference at the time of a 100% load. The actual logarithmic average temperature difference of the absorber is calculated from the temperature detected by the temperature detector and the absorption liquid inlet temperature detector, and the ideal logarithmic average temperature difference with respect to the cold water load is calculated.
An abnormality detector for comparing the logarithmic average temperature difference and outputting an abnormality signal. 2. An absorption refrigerator in which a regenerator, a condenser, an evaporator, an absorber and the like are connected by piping, a concentrated liquid temperature detector for detecting an absorption liquid temperature at an outlet side of the regenerator, and a condenser. A condensing temperature detector for detecting the condensing temperature of the evaporator, a chilled water temperature detector for detecting the chilled water inlet temperature and the outlet temperature of the evaporator, and an absorbent outlet temperature detector for detecting the temperature of the absorbent on the outlet side of the absorber. , A cooling water temperature detector that detects the cooling water inlet temperature and the outlet temperature of the absorber, a pressure detector that detects the pressure in the absorber, and a temperature of the concentrated liquid detected by the concentrated liquid temperature detector, The concentration of the concentrated absorbent to be sprayed on the absorber is calculated from the condensing temperature detected by the condensation temperature detector, and the concentrated absorbent dispersed to the absorber from the concentration of the concentrated absorbent and the pressure detected by the pressure detector. Determine the temperature and determine the temperature of the concentrated absorbent and the outlet side of the absorber. The actual logarithmic average temperature difference of the absorber is calculated from the collected liquid temperature and the cooling water inlet / outlet temperature detected by the cooling water temperature detector, and the difference between the detected temperature of each chilled water temperature detector and the chilled water inlet / outlet at 100% load. An absorption detector for calculating a chilled water load from the temperature difference, comparing the ideal logarithmic average temperature difference with the actual logarithmic average temperature difference with respect to the chilled water load, and outputting an abnormality signal. Machine abnormality detection device.