JP3030225B2 - How to stop absorption chiller operation - 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 control method for stopping operation.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. Sho 61-36661 discloses that after stopping heating in a high-temperature regenerator, a refrigerant pump and an absorbent pump are operated for a predetermined time by a timer to prevent crystallization of the absorbent. For this reason, an operation stop technique for performing a dilution operation has been disclosed.

[0003]

However, in the case of the above-mentioned prior art, since the dilution operation time of a predetermined length is only set by a timer, the concentration of the concentrated absorbent in the absorption refrigerator is low, and the dilution operation is performed. Even when the time is short, the refrigerant pump and the absorption liquid pump are operated only for a predetermined time, so that there is a problem that the operation is wasted.

In the above-described control method in which a cooling water pump and a load pump of a load pipe provided in an absorption refrigerator are operated for a predetermined time by a timer during a dilution operation, these pumps have a large capacity, so that the dilution operation is short. However, there is also a problem that the operation of each pump consumes a large amount of power wastefully.

[0005] For this reason, there has been a demand for a method of stopping the operation, which can suppress useless operation of each of the pumps during the dilution operation, reduce the power consumption, and reduce the operation cost.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention relates to the operation of an absorption refrigerator constituting a refrigeration cycle by connecting an absorber, a regenerator, a condenser, an evaporator and the like with piping. In the stopping method,

After the operation stop signal of the absorption refrigerator is inputted, the temperature of the absorbent in the regenerator is monitored, and when the temperature of the absorbent drops below a predetermined temperature with the stop of the heating in the regenerator, the absorber And a cooling water pump that supplies cooling water to the condenser, and an operation stop method of the first configuration in which the operation of the refrigerant pump that circulates the refrigerant is stopped,

[0008] In the operation stop method of the first configuration,
When a predetermined time has elapsed since the operation stop signal of the absorption refrigerator was input, even if the temperature of the absorbent in the regenerator did not drop below the predetermined temperature, the operation of the cooling water pump and the refrigerant pump was stopped. An operation stop method of the second configuration;

After the operation stop signal of the absorption refrigerator is input, the temperature of the absorbent in the regenerator is monitored, and when the temperature of the absorbent drops below a predetermined temperature due to the stop of the heating in the regenerator, the absorption liquid is monitored. An operation stop method of a third configuration in which the operation of the absorbent pump for circulating water is stopped, and

In the operation stopping method according to the third configuration,
A fourth configuration in which the operation of the absorbent pump is stopped when a predetermined time has elapsed since the operation stop signal of the absorption refrigerator was input, even if the temperature of the absorbent in the regenerator did not drop below the predetermined temperature. How to stop the operation of

[0011] After the operation stop signal of the absorption refrigerator is input, the temperature of the absorbent in the regenerator is monitored. When the temperature of the absorbent drops to a first predetermined temperature or less with the stop of the heating in the regenerator, The operation of the cooling water pump that supplies cooling water to the absorber and the condenser and the operation of the refrigerant pump that circulates the refrigerant are stopped, and when the temperature of the refrigerant drops below a second predetermined temperature lower than the first predetermined temperature, the absorption liquid is circulated. An operation stop method of a fifth configuration in which the operation of the absorbent pump to be stopped is stopped;

[0012] In the operation stop method of the fifth configuration,
When the first predetermined time elapses after the operation stop signal of the absorption refrigerator is input, the operation of the cooling water pump and the refrigerant pump is performed even if the temperature of the absorbent in the regenerator does not drop below the first predetermined temperature. When the operation is stopped and the second predetermined time longer than the first predetermined time has elapsed, the operation of the absorption liquid pump is stopped even if the temperature of the absorption liquid of the regenerator does not drop below the second predetermined temperature. By providing an operation stop method of a sixth configuration, the problem of the related art is solved.

[0013]

When the operation of the absorption chiller is stopped, each pump is stopped when the temperature of the absorbent in the regenerator falls below a predetermined temperature set for each pump. In addition, the energy consumption during the dilution operation is reduced, which makes it possible to reliably reduce the operation cost.

Further, in the invention of claims 2, 4, and 6, the stop of each pump is controlled in combination with the elapsed time from the input of the stop signal of the absorption refrigerator. Even if an abnormality occurs in the means for monitoring the temperature of the absorbent, the dilution operation can be reliably terminated by measuring the elapsed time after the input of the operation stop signal.

In the invention of claims 5 and 6, since the absorbing liquid pump stops at a temperature lower than the stop temperature of the cooling water pump and the refrigerant pump, the energy consumption of the cooling water pump and the refrigerant pump is reduced. There is a more reliable dilution driving effect.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. The example illustrated in FIG. 1 is a double effect absorption refrigerator in which water (H ₂ O) is used as a refrigerant and a lithium bromide (LiBr) aqueous solution is used as an absorbent (absorbing liquid).

In FIG. 1, 1 is a high-temperature regenerator provided with a gas burner 1B, 2 is a low-temperature regenerator, 3 is a condenser, 4 is an evaporator, 5 is an absorber, 6 is a low-temperature heat exchanger, 7 is a high-temperature heat exchanger. Exchanger, 8-12 are absorbent pipes, 15 is an absorbent pump, 16
Numeral 18 is a refrigerant pipe, 19 is a refrigerant pump, 20 is a gas pipe connected to the gas burner 1B, 21 is a heating control valve for controlling the amount of heating by adjusting the gas flow rate, 22 is a cold water pipe (load pipe), Each is connected by piping 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 cold water pipe 2
The load pump 29 provided in the middle of 2 is a cooling water pump provided in the middle of the cooling water pipe 25, and the capacity of the load pump 28 and the cooling water pump 29 is larger than the absorption liquid pump 15 and the refrigerant pump 19.

The high temperature regenerator 1 detects the temperature of an absorbing solution (intermediate liquid) inside the high temperature regenerator 1 (hereinafter referred to as high temperature regenerator temperature T) and outputs the detected temperature to a control device 32. Temperature detector.

The control device 32 has a built-in microcomputer provided with required functions such as timekeeping, storage, calculation, comparison, and the like. As shown in FIG. 2, first, the temperature detector 31 monitors (detects) the temperature T of the high-temperature regenerator.
And starts the timing of the elapsed time t from the input of the operation stop signal, and outputs a signal of low combustion control for suppressing the heating power of the gas burner 1B by narrowing the opening of the heating control valve 21. is there.

When the high-temperature regenerator temperature T detected by the temperature detector 31 falls below a first predetermined temperature T1 (for example, 120 ° C.), the control device 32 outputs a required control signal and outputs a required control signal. When the operation of the cooling water pump 19 and the cooling water pump 29 is stopped, and the high-temperature regenerator temperature T falls below a second predetermined temperature T2 (for example, 100 ° C.) lower than the first predetermined temperature T1, a required control signal is output. The operation of the absorbent pump 15 is also stopped.

The control device 32 determines that the elapsed time t is the first time.
If the refrigerant pump 19 and the cooling water pump 29 continue to operate when the predetermined time t2 has elapsed, a required control signal is output to stop them, and the elapsed time t is reduced to the first predetermined time t2. When a longer second predetermined time t4 elapses, if the absorbing liquid pump 15 is operating, a required control signal is output and the control signal is stopped.

The first predetermined time t2 is set to be slightly longer even in the midsummer than the time during which the high temperature regenerator temperature T detected by the temperature detector 31 during normal operation falls below the first predetermined temperature T1. The second predetermined time t4 is also set to be slightly longer than the time during which the high temperature regenerator temperature T falls below the second predetermined temperature T2 during normal operation.

Further, the control device 32 performs low combustion control for reducing the thermal power of the gas burner 1B immediately after the input of the operation stop signal.
A predetermined time t1 shorter than the first predetermined time t2 (for example, 1
), And then the heating control valve 21 is closed to stop heating in the high-temperature regenerator 1. Also,
When a predetermined time t3 corresponding to a predetermined time (for example, one minute) has elapsed after the operation of the refrigerant pump 19 and the cooling water pump 29 has stopped, a required signal is output to output the load pump 28.
It is also configured to stop the operation of.

Hereinafter, the operation of the absorption refrigerator having the above configuration will be described. During normal operation, the opening of the heating control valve 21 is adjusted based on, for example, the temperature of chilled water taken out from the chilled water pipe 22 to control the evaporation and separation of the refrigerant in the high-temperature regenerator 1 as in the conventional absorption refrigerator. Meanwhile, each of the pumps 15, 19, 28, and 29 is operated.

In order to stop the operation of the absorption chiller, for example, by operating a stop switch (both not shown) of the control panel and outputting a required operation stop signal, the required operation stop signal is output. The control device 32 that has received the operation stop signal operates based on the predetermined procedure of FIG. 2 and starts the dilution operation of the absorption refrigerator.

That is, the controller 32 controls the temperature detector 31
Monitoring of the high temperature regenerator temperature T and measurement of the elapsed time t are started, a required opening signal is output to the heating control valve 21, and the opening of the heating control valve 21 is reduced to reduce the thermal power of the gas burner 1B. In addition, the function of evaporating and separating the refrigerant in the high temperature regenerator 1 is reduced.

When a predetermined time t1 (for example, one minute) has elapsed since the low burn control of the gas burner 1B,
The control device 32 outputs a close signal to the heating control valve 21 to stop the combustion of the gas burner 1B.

During low combustion of the gas burner 1B, the absorption liquid pump 15, the refrigerant pump 19, the load pump 28, and the cooling water pump 29 continue to operate. Each of the pumps 15, 19, 28, and 29 continues to operate even after the combustion of the gas burner 1B is stopped, and all of the absorbing liquid, refrigerant, cold water, and cooling water circulate through the absorption refrigerator.

As described above, even after the combustion of the gas burner 1B is stopped and the heating action in the high-temperature regenerator 1 is stopped, the pumps 15, 19, 28 and 29 continue to operate.
The concentration of the concentrated absorbent flowing out of the low-temperature regenerator 2 gradually decreases. Further, since cold water is supplied to the load from the evaporator 4, the temperatures of the high-temperature regenerator 1 and the low-temperature regenerator 2 gradually decrease.

When the high-temperature regenerator temperature T detected by the temperature detector 31 falls below the first predetermined temperature T1, the control device 32 outputs a stop signal to the refrigerant pump 19 and the cooling water pump 29, respectively. Pumps 19 and 29 stop operating.

Even after the operation of the refrigerant pump 19 and the cooling water pump 29 is stopped, the absorption liquid pump 15 and the load pump 2
8 continues the operation, the absorbent circulates to the high-temperature regenerator 1 and the low-temperature regenerator 2, and the cold water of the load circulates to the evaporator 4 to continue the dilution operation.

Further, when a predetermined time t3 corresponding to a predetermined time (for example, one minute) elapses after the operation of the refrigerant pump 19 and the cooling water pump 29 is stopped, the control device 32 outputs a stop signal to the load pump 28, and The pump 28 stops operating.

After the operation of the load pump 28 is stopped, the absorbent pump 15 continues to operate, the absorbent circulates through the absorption refrigerator, and the concentration of the absorbent further decreases.

Then, when the high temperature regenerator temperature T detected by the temperature detector 31 falls below the second predetermined temperature T2,
The control device 32 outputs a stop signal to the absorbent pump 15,
The operation of this pump is stopped.

It should be noted that even if a problem occurs in the temperature detector 31 and the high-temperature regenerator temperature T detected by the temperature detector 31 does not become lower than the first predetermined temperature T1, the first predetermined time t1 elapses. Then, the control device 32 outputs a stop signal to the refrigerant pump 19 and the cooling water pump 29 to stop the operation of the respective pumps 19 and 29, and the high temperature regenerator temperature T
Even if the temperature does not become equal to or lower than the second predetermined temperature T2, when the second predetermined time t2 has elapsed, a stop signal is output to the absorbent pump 15 to stop the operation. Can be terminated.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the appended claims.

[0038]

As described above, the method for stopping the operation of an absorption refrigerator according to the present invention is such that the operation of each pump is stopped when the temperature of the absorbent in the regenerator falls below a predetermined temperature set for each. Therefore, the energy consumption during the dilution operation is reduced in spite of the simple configuration, whereby the operation cost can be reliably reduced.

Further, in the invention of claims 2, 4, and 6, the stop of each pump is controlled by using the elapsed time from the input of the operation stop signal of the absorption refrigerator. Even if an abnormality occurs in the means for monitoring the temperature of the absorbent, the dilution operation can be reliably terminated by measuring the elapsed time after the input of the operation stop signal.

In the fifth and sixth aspects of the present invention, the absorption liquid pump stops at a temperature lower than the stop temperature of the cooling water pump and the refrigerant pump, so that the energy consumption of the cooling water pump and the refrigerant pump is reduced. There is a more reliable dilution driving effect.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an apparatus.

FIG. 2 is an explanatory diagram illustrating an example of control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 1B Gas burner 2 Low temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 6 Low temperature heat exchanger 7 High temperature heat exchanger 8-12 Absorbent pipe 15 Absorbent pump 16-18 Refrigerant pipe 19 Refrigerant pump 20 Gas pipe Reference Signs List 21 heating control valve 22 chilled water pipe 25 cooling water pipe 26 absorber heat exchanger 27 condenser heat exchanger 28 load pump 29 cooling water pump 31 temperature detector 32 controller

Claims (6)

(57) [Claims] 1. A method for stopping the operation of an absorption refrigerator comprising a piping connected to an absorber, a regenerator, a condenser, an evaporator, etc., and comprising the steps of: Monitoring the temperature of the absorbent in the regenerator, and when the temperature of the absorbent drops below a predetermined temperature due to the stoppage of heating in the regenerator, a cooling water pump that supplies cooling water to the absorber and the condenser; Stopping the operation of a refrigerant pump for circulating water. 2. When a predetermined time has passed since the operation stop signal of the absorption refrigerator was input, the operation of the cooling water pump and the refrigerant pump was stopped even if the temperature of the absorbent in the regenerator did not drop below the predetermined temperature. 2. The method according to claim 1, wherein the operation of the absorption refrigerator is stopped. 3. A method for stopping the operation of an absorption refrigerator that constitutes a refrigeration cycle by connecting a pipe to an absorber, a regenerator, a condenser, an evaporator, etc. The temperature of the absorbent in the regenerator is monitored, and when the temperature of the absorbent drops below a predetermined temperature with the stop of heating in the regenerator, the operation of the absorbent pump for circulating the absorbent is stopped. To stop the operation of absorption refrigerators. 4. When a predetermined period of time has elapsed since the input of the operation stop signal of the absorption refrigerator, the operation of the absorption pump is stopped even if the temperature of the absorption liquid in the regenerator does not drop below the predetermined temperature. The method according to claim 3, wherein the operation of the absorption refrigerator is stopped. 5. A method for stopping the operation of an absorption refrigerator comprising a piping connected to an absorber, a regenerator, a condenser, an evaporator, etc., comprising the steps of: A cooling water pump that supplies cooling water to the absorber and the condenser when the temperature of the absorbing solution in the regenerator is reduced to a first predetermined temperature or less with the stop of heating in the regenerator; Stopping the operation of the refrigerant pump for circulating the refrigerant, and stopping the operation of the absorbent pump for circulating the absorbent when the temperature of the refrigerant pump falls below a second predetermined temperature lower than the first predetermined temperature. How to stop the operation of the refrigerator. 6. When the first predetermined time has elapsed since the input of the operation stop signal of the absorption refrigerator, the cooling water pump and the cooling water pump are connected even if the temperature of the absorbent in the regenerator does not drop below the first predetermined temperature. When the operation of the refrigerant pump is stopped and the second predetermined time longer than the first predetermined time has elapsed, the operation of the absorbent pump is stopped even if the temperature of the absorbent in the regenerator does not drop below the second predetermined temperature. The method according to claim 5, wherein the operation is stopped.