JPH0399168A - Absorptive type freezer - Google Patents

Abstract

PURPOSE:To uniform a reduction in a heat exchanging amount and prevent a substan tial reduction of a coefficient of performance by a method wherein a rate of tempera ture difference of absorbing liquid between an outlet port of an absorbing device and an inlet port of a regenerator in respect to a temperature difference between a cold water inlet and a cold water outlet of an evaporator is compared with a set value and then a signal is outputted and informing device operated in response to this signal is provided. CONSTITUTION:A rate of a temperature difference between a temperature of absorbed liquid at an outlet port of an absorbing device 5 and another temperature of an inlet port of a hot regenerator 1 and a physical amount varying in response to a variation of load of cold water of another temperature difference between a cold water inlet and a cold water outlet is calculated. This rate is compared with a set value, a control device 35 may output a signal and then an informing device 36 is operated in response to this signal. Due to this fact, when a crystal or the like is produced at heat exchangers 6 and 7 between the absorbing device 5 and the hot regenerator 1 and a heat exchanging amount is reduced, it is possible to inform a supervisor of it with an informing device 36 and an inspecting operation can be carried out for the heat exchangers 6 and 7 before a coefficient of performance of an absorptive freezer is substantially decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an absorption chiller (2g!), and more particularly to an absorption chiller equipped with a heat exchanger.

(Example) Conventional technology For example, in Japanese Patent Publication No. 58-24705, first and second heat exchangers are provided between the absorber and the generator, and the diluted absorption liquid flowing out from the absorber is exchanged with the second generator. The concentrated absorption liquid flowing to the absorber is heat exchanged with the first heat exchanger (low-temperature heat exchanger), and the dilute absorption liquid flowing from the first heat exchanger to the first generator is exchanged with the first heat exchanger. An absorption refrigerator is disclosed that exchanges heat with an intermediate absorption liquid flowing to a second generator in a second heat exchanger (high temperature heat exchanger). In the absorption refrigerator described in
The concentrated absorption liquid crystallizes in the heat exchanger, and this crystallization reduces the inner diameter of the heat transfer tubes of the first heat exchanger and the second heat exchanger. Then, the flow rate of the concentrated absorption liquid or the rolled intermediate absorption liquid decreases, and the amount of heat exchanged between the concentrated absorption liquid or intermediate absorption liquid and the dilute absorption liquid in the first heat exchanger or the second heat exchanger decreases. If the absorption refrigerator is operated as it is, the temperature of the dilute absorption liquid sent to the first generator via the first heat exchanger and second heat exchanger will decrease, and the amount of heating in the first generator will decrease. The problem has been that the amount of fuel increases and the operating efficiency decreases.

The purpose of the present invention is to notify a manager, etc. of a decrease in the amount of heat exchanged in a heat exchanger, and to prevent a significant decrease in the coefficient of performance. In order to solve the above problems, the temperature of the absorption liquid changes depending on the difference between the temperature of the absorption liquid on the outlet side of the absorber (5) and the temperature of the absorption liquid on the inlet side of the high-temperature regenerator (1) and the cold water load of the evaporator (4). A control device (35) that calculates the ratio between the temperature difference at the cold water inlet and outlet, compares this ratio with a set value, and outputs a signal, and an alarm that operates by inputting the signal from this control device (35). The present invention provides an absorption refrigerator equipped with a container (36).

Also, the difference between the absorption liquid temperature on the inlet I1 side of the low-temperature heat exchanger (6) and the absorption liquid temperature on the outlet side of the high-temperature heat exchanger (7) and the evaporator (
4) A control device that calculates the ratio of cold water inlet and outlet [1] to the temperature difference, compares this ratio with a set value, and outputs a signal <35
) and an alarm (36) that operates by inputting a signal from the control device (35). Due to the decrease in temperature, the temperature of the dilute absorption liquid flowing out from the absorber (5) decreases, and the temperature of the concentrated absorption liquid flowing from the low-temperature regenerator (2) decreases significantly in the low-temperature heat exchanger (6). Then, crystals are generated and the amount of concentrated absorption liquid flowing through the low temperature heat exchanger (6) is reduced. Then, the difference between the temperature of the diluted absorption liquid on the outlet side of the absorber <5> and the temperature of the diluted absorption liquid on the inlet r:J side of the high-temperature regenerator (1) decreases, and the ratio of the difference in the cooling water inlet and outlet temperatures to this difference decreases. When becomes 15 or less, the control device (35) outputs a signal to the alarm (36). Then, the alarm (36) operates to notify the administrator of the decrease in the amount of heat exchange in the low-temperature heat exchanger (6) or the high-temperature heat exchanger (7). 〉
compares the ratio of the temperature difference between the chilled water inlet and outlet and the dilute absorption liquid temperature difference with the set value and outputs a signal to the alarm (36). It is also possible to prevent the alarm (36) from malfunctioning even if the When the amount of concentrated absorption liquid flowing through the exchanger (6) decreases, the amount of heat exchanged between the dilute absorption liquid and the concentrated absorption liquid in the low temperature heat exchanger (6) decreases. The difference between the temperature of the dilute absorbent at the outlet side of the high temperature heat exchanger (7) decreases.Then, the ratio of the temperature difference between the cold water inlet and outlet to this dilute absorbent temperature difference decreases, and this ratio becomes 15. When the control device (3
5) outputs a notification signal, and the notification device (36) operates to notify the administrator of a decrease in the amount of heat exchanged in the low-temperature heat exchanger (6) or the high-temperature heat exchanger (7). Furthermore, even when the temperature difference of the diluted absorbent liquid changes due to load fluctuations, it is possible to prevent the alarm device (36>) from malfunctioning.

(F) Example Hereinafter, an example of the present invention will be described in detail based on the drawings.

The one shown in Figure 1 is a dual-effect absorption refrigerator, in which the refrigerant is water (U*O) and the absorbent (absorbing liquid) is lithium bromide (L).
iBr) using an aqueous solution.

In Figure 1, (1) a high-temperature regenerator equipped with an insulating gas burner (IB), (2) a low-temperature regenerator, (3> a condenser,
4) is an evaporator, (5) is an absorber, (6) is a low temperature heat exchanger, <7) is a high temperature heat exchanger, (8A), (8B),
(sc), and (9) to (12) are absorption liquid piping,
(15) is an absorption liquid bomb, <16> to (18) discharge refrigerant pipes, (19) is a refrigerant bomb, (20) is a gas pipe connected to a gas burner (1B>), (21> is a heating amount control valve, (22) is a cold water pipe, and each pipe is connected as shown in Fig. A condenser heat exchanger (26) and a condenser heat exchanger (27) are provided.

(31) and (32) are the cooling water pipes (22), respectively.
These are a cold water inlet temperature detector (hereinafter referred to as a first temperature detector) and a cold water outlet temperature detector (hereinafter referred to as a second temperature detector) attached to the inlet side and outlet side of the evaporator (4). In addition, (33) is a temperature detector (hereinafter referred to as the third temperature sensor) that is attached to the absorption liquid pipe (8A) and detects the temperature of the diluted absorption liquid on the outlet side of the absorber <5>, and (34> is the temperature sensor for detecting the temperature of the diluted absorption liquid on the outlet side of the absorber <5>). This is a temperature detector (hereinafter referred to as the fourth temperature detector) that is attached to the pipe (8C) and detects the temperature of the dilute absorption liquid on the input side of the high temperature regenerator (1). 3
1). It is a control device that operates by inputting signals from (32), (33), and (34), and (35) is an alarm that operates by inputting a signal from the control device (35>). The alarm (36) is composed of a display (37) composed of a plurality of light emitting elements and a puzzer (38). ), or in the control room of the absorption chiller.

Hereinafter, the above control device (35) will be explained in detail based on FIG. 2. Here, the same parts as in FIG.
〉 is composed of a microcomputer, and (4
0> is an input interface that converts and outputs the signal from each temperature sensor, (41> is an input interface (
This is a central processing unit (hereinafter referred to as CPU) that operates by inputting signals output from 40>. Further, (42> is a memory element (hereinafter referred to as ROM), and the ROM (42) contains a program for calculating the difference between the cold water inlet temperature and the cold water outlet temperature, that is, the cold water temperature difference, and a program on the outlet side of the absorber (5). A program that calculates the difference between the dilute absorption liquid temperature and the dilute absorption liquid temperature on the inlet side of the high temperature regenerator (1), that is, a dilute absorption liquid temperature difference, a program that calculates the ratio of the dilute absorption liquid temperature difference to the cold water temperature difference, and a program for comparing the above ratio and the set value. Also, <43) is for each temperature detector (31).
, (32), (33), (34) A memory element (hereinafter referred to as RA) that temporarily stores the temperature data detected by
44 is an output interface that converts and outputs the signal output from the CPU (41). A signal is then output from the output interface (44) to the alarm (36). Further, (45) is a CLOCK that outputs a signal zero every predetermined time (for example, one minute). When the absorption chiller is operated, the refrigerant evaporated in the high temperature regenerator (1) passes through the low temperature regenerator (2) and flows to the condenser (3), similar to the conventional absorption chiller, and flows into the condenser heat exchanger (27). After exchanging heat with the water flowing through the water pipe (17), the refrigerant is condensed and liquefied, and then flows to the evaporator (4) via the refrigerant pipe (17).
It evaporates by exchanging heat with the water in the cold water pipe (22), and the water in the cold water pipe (22) is cooled by the heat of vaporization.

Then, the cold water is circulated to the load to perform cooling operation. Further, the refrigerant evaporated in the evaporator (4) is absorbed into an absorption liquid in the absorber (5). Then, the absorption liquid whose concentration has become diluted by absorbing the refrigerant is sent to the high-temperature regenerator (1>) through the low-temperature heat exchanger (6>) and the high-temperature heat exchanger (7>) by the operation of the absorption liquid bomb (15). The absorption liquid that has entered the high temperature regenerator (1) is heated by the burner (IB>, the refrigerant is evaporated, and the medium concentration absorption liquid passes through the high temperature heat exchanger (7) and is transferred to the low temperature regenerator (1).
Enter 2>. Then, the absorption liquid is heated by the refrigerant vapor flowing through the refrigerant pipe (16) from the high-temperature regenerator (1), and the refrigerant is further evaporated and separated, increasing its concentration. The highly concentrated absorption liquid (hereinafter referred to as concentration) is transferred to a low-temperature heat exchanger (6).
The temperature of the water is lowered, and the water is sent to the absorber (5) where it is dispersed.

As described above, when the absorption refrigerator is operating, each temperature detector, (31), (32) . (33). (
34) detects the cold water temperature and the temperature of the dilute absorption liquid. Hereinafter, the operation of the control device (35) will be explained based on the broaching process shown in FIG. When the absorption refrigerator is operating, each temperature detector (31), (32), (33),
The temperature data detected by (34) is stored in RAM (43) via input interface (40) and CPU (41). Then, when CLO C K (45) counts up and outputs a signal to CPU (4l), CPU (41) operates based on this signal and R A M
Read the temperature data from (43). Also, CPU (41
) reads each of the above programs from the ROM (42) and operates to calculate the cold water temperature difference, the diluted absorption liquid temperature difference, and the ratio of the diluted absorption liquid temperature difference to the cold water temperature difference. Here, the load is, for example, 100%, the temperature difference between the cold water inlet and outlet is 5°C, the temperature of the diluted absorption liquid on the outlet side of the absorber (4) is 40"C, and the temperature of the diluted absorption liquid on the inlet side of the high temperature regenerator (1) is 140"C. When the temperature difference of the diluted absorbent liquid is 100"C at 100°C, the ratio of the temperature difference of the diluted absorbent liquid to the cold water temperature difference is . =20. And R.O.M.
The CPU (41) compares the set value, for example 15, stored in (42) with the calculated ratio 20, and when the calculated ratio is greater than the set value, the CPU (41) outputs the output interval (44). No signal is output to the output interface (44), and no notification signal is output from the output interface (44).

Therefore, the alarm (36>) does not operate.

After that, the load hardly changed and the temperature difference between the cold water inlet and outlet was 5.
For example, if the temperature of the dilute absorption liquid flowing through the low-temperature heat exchanger (6) decreases and the temperature of the concentrated absorption liquid decreases significantly, the temperature of the concentrated absorption liquid in the low-temperature heat exchanger (6>) decreases. The liquid crystallizes.For this crystallization, a low temperature heat exchanger (6
) gradually decreases the inner diameter of the heat exchange pipe (not shown), the amount of concentrated absorption liquid flowing through the low temperature heat exchanger (6) decreases. Furthermore, the flow rate of the concentrated absorption liquid is also reduced due to sludge in the low temperature heat exchanger (6). Then, the amount of heat exchange between the concentrated absorption liquid and the dilute absorption liquid decreases. For this reason. For example, when the dilute absorbent temperature difference decreases from 100°C to 75°C, and the ratio of the dilute absorbent temperature difference 75 to the cold water temperature difference becomes 15, the CPU (41) outputs the output interface. A signal is output to the face (44). Based on this signal, the output interface (44) outputs a notification signal to the notification device (36>).The notification device (36) operates when the notification signal is input, and the display device (37) displays, for example, the words ALARM. blinks and the buzzer (38) sounds. Then, the administrator turns on the low-temperature heat exchanger (6) by blinking the characters on the display (37) or by sounding the buzzer (38).
) or the amount of heat exchanged by the high-temperature heat exchanger (7) has decreased, for example, each heat exchanger is blinked while the absorption chiller is stopped, and replacement work for the low-temperature heat exchanger (6) is performed. be exposed. or,
When crystals occur in the high temperature heat exchanger (7), the amount of heat exchange decreases and the temperature difference of the diluted absorption liquid decreases, and the ratio of the diluted absorption liquid temperature difference to the cold water temperature difference becomes 15 or less, the controller (35) 〉
outputs a notification signal, and the notification device (36) operates. Inspections and the like are then performed in the same manner as above.

Further, the load and the temperature difference between the cold water inlet and outlet are almost proportional; for example, when the load is 80%, the temperature difference between the cold water inlet and outlet is 4°C, and when the load is 60%, the temperature difference between the cold water inlet and outlet is 3°C.

In addition, as the load decreases, the amount of heating in the high temperature regenerator (1) also decreases, and the heat is transferred from the high temperature regenerator (1) through the high temperature heat exchanger (7) and the low temperature regenerator (2) to the low temperature heat exchanger (2). 6) The temperature of the intermediate absorption liquid and the concentrated absorption liquid flowing into the tank decreases.The temperature difference of the diluted absorption liquid also decreases, for example, when the load is 80%, the temperature difference of the diluted absorption liquid decreases to, for example, 80°C, When the ratio of the rare absorption 80 and collected liquid temperature difference to the cold water temperature difference is T=20 and is larger than the set value, the CPU (41) outputs the output interface (
44>, and the alarm (36) does not operate. Also, if the dilute absorbent temperature difference is, for example, 64°C, and the load is 100%, the temperature at which the alarm (36) operates will be reached, but if the load is 80%, the above ratio will change. Since T=16, the CPU (41) does not output a signal and the alarm (36>) does not operate.

In addition, crystals are generated in the low temperature heat exchanger (6), and the amount of heat exchanged in the low temperature heat exchanger (6) decreases, and the dilute absorption liquid temperature difference decreases to 60"C or less, and the above The ratio is T=15
When the value is below, the CPU (41) outputs a signal to the output interface (44). Then, the output interface (44) outputs the notification signal to the notification device (36>), and the notification device (36) operates in the same manner as when the load is 100%. Also, when the load is, for example, 60% ( The temperature difference between the cold water inlet and outlet is 3
When the dilute absorption liquid temperature difference becomes 45 degrees Celsius or less, a signal is output to the dilute absorption liquid temperature difference relative to the cold water inlet/outlet temperature difference interface (44), and the alarm (36>) is activated.

Similarly, when the load changes, the CPU (41) connects the output interface (44) to
The alarm (36) is activated.

According to the above embodiment, crystals are generated in the low temperature heat exchanger (6) or the high temperature heat exchanger (7>) during operation of the absorption refrigerator,
The amount of absorption liquid flowing through the low-temperature heat exchanger (6) or the high-temperature heat exchanger (7) decreases, the amount of heat exchanged between the concentrated absorption liquid or intermediate absorption liquid and the dilute absorption liquid decreases, and the temperature difference between the cold water inlet and outlet decreases. When the ratio of the dilute absorption liquid temperature difference to Therefore, it is possible to notify the administrator of the decrease in the heat exchange amount of the low temperature heat exchanger (6>), and the administrator can notify the administrator of the decrease in the heat exchange amount of the low temperature heat exchanger (6> or high temperature heat exchanger? 7). Therefore, it is possible to perform an inspection and replace the low-temperature heat exchanger (6) or the high-temperature heat exchanger before the coefficient of performance of the absorption refrigerator drops significantly.

In addition, since the alarm (36) is operated by comparing the ratio of the temperature difference between the cold water inlet and outlet to the temperature difference of the diluted absorbent liquid and the set value, which changes according to the change in load, the load decreases and the temperature of the diluted absorbent liquid decreases. It is possible to avoid malfunction of the alarm (36) when the difference decreases.In addition, in the above embodiment, the third and fourth
Temperature detectors (33) and (34) were installed on the absorption liquid piping (8A) and (8C), respectively, but the third temperature sensor (33) was installed on the absorption liquid reservoir (5A) of the absorber (5). However, the fourth temperature sensor (34) is also connected to the absorption liquid piping {8
B} may be provided. Here, the fourth temperature detector (34)
is installed in the absorption liquid piping (8B), the alarm (36
The ratio of the dilute absorption liquid temperature difference to the cold water inlet/outlet temperature difference when operating the above is set smaller than 15 of the above embodiment. Further, in the above embodiment, the ratio of the dilute absorption liquid temperature difference to the cold water inlet/outlet temperature difference when operating the alarm (36) is set to 15, but this set value is not limited to 15.

(G) Effects of the Invention The present invention is an absorption refrigerating machine configured as described above, which is characterized by the difference between the absorption liquid temperature on the outlet side of the absorber and the absorption liquid temperature on the inlet side of the regenerator and the cold water inlet/outlet of the evaporator. Calculates the ratio with physical quantities that change according to changes in chilled water load such as temperature difference, compares this ratio with a set value, and outputs a signal.This signal activates the alarm, so the absorption If crystals occur in the heat exchanger between the regenerator and the regenerator and the amount of heat exchange decreases, an alarm can be used to notify the administrator, etc., before the coefficient of performance of the absorption chiller decreases significantly. It is possible to perform inspection work on heat exchangers, etc. In addition, the ratio between the temperature difference between the cold water inlet and outlet, which changes depending on the load, and the temperature difference of the above-mentioned absorption liquid is calculated, and the control device outputs a signal based on this ratio, so if the load changes and the temperature difference between the cold water inlet and outlet changes. This can also prevent alarm malfunctions.

Also, calculate the ratio of the difference between the temperature of the absorption liquid on the inlet side and the absorption liquid temperature on the output 11 side of the heat exchanger provided between the absorber and the regenerator and the difference in the temperature of the cold water inlet and outlet of the evaporator. The control device outputs a signal by comparing the ratio with the set value, and this signal activates the alarm, so when the heat exchange amount of the heat exchanger decreases, it can notify the administrator etc., and the performance of the absorption chiller can be monitored. It is possible to perform inspection work on the heat exchanger before the coefficient decreases significantly, and it is also possible to prevent malfunction of the alarm when the load changes.

[Brief explanation of drawings]

Fig. 1 is a circuit configuration diagram of an absorption refrigerator showing an embodiment of the present invention, Fig. 2 is a block diagram of a control device, and Fig. 3 is a block diagram of a control device.
The figure is a flowchart for explaining the operation of the alarm. (1)...High temperature regenerator, (4)...Evaporator, (
5)...Absorber, (6)...Low temperature heat exchanger, <
35)...Control device, (36)...Alarm device.

Claims (1)

[Claims] 1. Absorber, regenerator, provided between the regenerator and the absorber to exchange heat between the absorption liquid flowing from the absorber to the regenerator and the absorption liquid flowing from the regenerator to the absorber. In an absorption refrigerator in which a heat exchanger and an evaporator are connected through piping, the difference between the temperature of the absorption liquid on the outlet side of the absorber and the temperature of the absorption liquid on the inlet side of the regenerator, and the temperature difference between the cold water inlet and outlet of the evaporator. Absorption refrigeration characterized by comprising: a control device that calculates a ratio between the two, compares this ratio with a set value, and outputs a signal; and an alarm that operates using a signal from the control device as an input signal. Machine. 2. Absorber, regenerator, heat exchanger installed between the absorber and regenerator to exchange heat between the absorption liquid flowing from the absorber to the regenerator and the absorption liquid flowing from the regenerator to the absorber, and evaporation. In an absorption chiller with pipes connected to each other, calculate the ratio of the difference between the temperature at the absorption liquid inlet side and the temperature at the absorption liquid outlet side of the heat exchanger and the temperature difference between the cold water inlet and outlet of the evaporator, and calculate the ratio between this ratio and the set value. 1. An absorption refrigerating machine comprising: a control device that compares and outputs a signal; and an alarm that operates by inputting a signal from the control device. 3. The absorber, the regenerator, the heat exchanger installed between the regenerator and the absorber, the evaporator, etc. are each connected by piping, and the heat exchanger is installed between the absorber and the regenerator. In an absorption chiller, calculate the ratio between the difference between the absorbent temperature on the inlet side of the heat exchanger and the absorbent liquid temperature on the outlet side and a physical quantity that changes depending on the chilled water load of the evaporator, and calculate the ratio between this ratio and the set value. 1. An absorption refrigerating machine comprising: a control device that compares and outputs a signal; and an alarm that operates by inputting a signal from the control device.