JP2000274864A - Method for controlling absorption refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a running cost when an absorption refrigerator is operated with a partial load. SOLUTION: The method for controlling an absorption refrigerator comprises the steps of regulating a flow rate of a chilled or warm water supplied to an air conditioning load based on an air conditioning load factor calculated from a temperature T1 of the water returned to an evaporator 4, a temperature T2 of the water fed from the evaporator 4 and a pressure difference ΔP of an outlet and an inlet of the evaporator 4 of a chilled or warm water tube 21, further detecting the temperatures T1, T2 of the water for a predetermined time, calculating a correcting flow rate of the water from deviations of the temperatures T1, T2 of the water from a set temperature when a rated operation if change widths ΔT1, ΔT2 fall within a predetermined temperature, and correcting it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption type refrigerator for cooling and heating by circulating and supplying cooled or heated brine to an air conditioning load or the like.

[0002]

2. Description of the Related Art In an absorption refrigerator, the magnitude of a heat load such as an air-conditioning load is determined by a temperature difference between a temperature of brine supplied to the heat load and a temperature of brine returned from the heat load. The amount of heat to be supplied to the regenerator is controlled based on the obtained magnitude, and the amount of the refrigerant evaporated and separated in the regenerator is controlled to adjust the capacity.

[0003]

However, in the above-mentioned conventional absorption refrigerator, even when the heat load is a small partial load, the amount of brine supplied to the heat load and the amount supplied to the absorber and the condenser are supplied. Since the flow rate of the cooling water was the same as that during the rated load operation, there was a problem that it was not possible to reduce the power cost of transporting brine and cooling water even when the load was small. Had been an issue.

[0004]

According to the present invention, as a specific means for solving the above-mentioned problems in the prior art, the magnitude of the heat load is determined based on the difference in temperature between the inlet and outlet of the brine which is cooled or heated and circulated to the heat load. And controlling the amount of thermal operation on the brine based on the magnitude of the heat load, and controlling the amount of brine circulated.In an absorption refrigerator, when the magnitude of the heat load is less than the rated load, First, the amount of circulation is controlled based on the ratio of the heat load to the rated load, and based on the difference between the temperature of the inlet / outlet of the brine circulating at this amount of circulation and the set temperature of the inlet / outlet of the brine during the rated operation. A first control method for obtaining a correction value of the amount of brine circulation and correcting the amount of brine circulation;

[0005] The magnitude of the thermal load is determined from the temperature difference between the inlet and the outlet of the brine which is cooled or heated and circulated to the thermal load, and the amount of thermal operation on the brine is controlled based on the magnitude of the thermal load. And in the absorption refrigerator controlling the flow rate of the cooling water supplied to the condenser, when the magnitude of the heat load is less than the rated load, the flow rate of the cooling water is first controlled based on the ratio of the heat load to the rated load. Then, a correction value of the flow rate of the cooling water is obtained based on a difference between the temperature of the inlet / outlet portion of the brine when the cooling water is set at this flow rate and the set temperature of the inlet / outlet portion of the brine during the rated operation, and the flow rate of the cooling water is determined. A second control method for correcting, and

[0006] The magnitude of the thermal load is determined from the temperature difference between the inlet and outlet of the brine that is cooled or heated and circulated to the thermal load, and the amount of thermal operation on the brine is controlled based on the magnitude of the thermal load. In the absorption refrigerator in which the circulation amount and the flow rate of the cooling water supplied to the absorber and the condenser are controlled, when the magnitude of the heat load is less than the rated load, the flow rates of the brine and the cooling water are adjusted to the rated heat load. First, control is performed based on the ratio to the load, and the brine and the cooling water are set based on the difference between the temperature of the inlet and outlet of the brine when the brine and the cooling water are set to this flow rate and the set temperature of the inlet and outlet of the brine during the rated operation. A third control method for obtaining a correction value of the flow rate of the second and correcting the flow rates of the brine and the cooling water;

An absorption chiller that determines the magnitude of the thermal load from the difference in temperature between the inlet and outlet of the brine that is cooled or heated and circulates and supplies the thermal load to the thermal load, and that controls the amount of thermal operation on the brine based on the magnitude of the thermal load. When the temperature of the cooling water supplied to the absorber and the condenser is lower than the rated temperature, the flow rate of the cooling water is first controlled based on the relational expression between the fuel consumption ratio and the refrigeration capacity ratio determined for each cooling water temperature. Then, a correction value of the flow rate of the cooling water is obtained based on a difference between the temperature of the inlet / outlet of the brine when the cooling water is set at this flow rate and the set temperature of the inlet / outlet section of the brine during the rated operation. A fourth control method for correcting

[0008] In the control method according to any one of the first to fourth configurations, the magnitude of the heat load is obtained by a calorie meter to which the temperature difference between the inlet and the outlet of the brine and the flow rate of the brine are inputted. By providing a control method, the above-mentioned problem of the related art is solved.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. The example illustrated in FIG. 6 is a double-effect absorption refrigerator that circulates cold or hot water as brine to a heat load (not shown), and uses water as a refrigerant and an aqueous solution of lithium bromide (LiBr) as an absorption liquid. Things.

In the figure, 1 is a high temperature regenerator provided with a heating 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, 8-11 are absorption liquid pipes, 13 is absorption liquid pump, 14-
18 is a refrigerant pipe, 19 is a refrigerant pump, 21 is a cold / hot water pipe through which cold or hot water circulates to an air conditioning load (not shown), 22 is a cold / hot water pump, 23 is a cooling water pipe, 24 is a cooling water pump, and 25 and 26 are equalizers. The pressure pipes and 27 to 30 are on-off valves, and these devices are respectively connected by piping as shown in FIG. 6, and the configuration itself is well known in the related art.

[0011] In the double effect absorption refrigerator having the above structure, the on-off valves 27, 28, 29, and 30 are closed, the cooling water pump 24 is started to flow cooling water, and the heating burner 1B
When the rare absorbing liquid is heated by the high-temperature regenerator 1 and the refrigerant vapor is evaporated and separated from the rare absorbing liquid, an intermediate absorbing liquid in which the refrigerant vapor is separated and the concentration of the absorbing liquid is increased is obtained.

The high-temperature refrigerant vapor generated by the high-temperature regenerator 1 enters the low-temperature regenerator 2 through the refrigerant pipe 14 and is generated by the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 7 by the absorbing liquid pipe 9. Then, the intermediate absorbing liquid that has entered the low-temperature regenerator 2 is radiated and condensed by heating and enters the condenser 3.

The refrigerant heated in the low-temperature regenerator 2 and evaporated and separated from the intermediate absorbing liquid enters the condenser 3 and enters the cooling water pipe 2.
The refrigerant flows into the evaporator 4 through the refrigerant pipe 16 together with the refrigerant condensed and supplied from the refrigerant pipe 14 by exchanging heat with the water flowing in the inside 3.

The refrigerant liquid entering the evaporator 4 and stored in the refrigerant liquid reservoir is sprayed by a refrigerant pump 19 onto a heat transfer tube 21 A connected to the cold / hot water pipe 21, and is supplied with water supplied through the cold / hot water pipe 21. The heat exchange evaporates and cools the water flowing inside the heat transfer tube 21A.

The refrigerant evaporated in the evaporator 4 enters the absorber 5 and is heated in the low-temperature regenerator 2 to evaporate and separate the refrigerant. It is supplied through the low-temperature heat exchanger 6 and is absorbed by the concentrated absorbent sprayed from above.

The absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 5, that is, the diluted absorption liquid, is regenerated at a high temperature via the low-temperature heat exchanger 6 and the high-temperature heat exchanger 7 by the operation of the absorption liquid pump 13. It is sent from the absorbing liquid tube 8 to the vessel 1.

When the absorption chiller is operated as described above, the cold water cooled by the heat of vaporization of the refrigerant in the heat transfer pipe 21A piped inside the evaporator 4 is cooled by the operation of the cold / hot water pump 22. Since the air-conditioning load (not shown) can be circulated and supplied through the water pipe 21, a cooling operation or the like can be performed.

On the other hand, the opening / closing valves 27, 28, 29, and 30 are opened, and the heating burner 1B
When the rare absorbent is heated by the high-temperature regenerator 1 and the refrigerant evaporated from the rare absorbent in the high-temperature regenerator 1, the refrigerant mainly passes through the refrigerant pipes 14 and 15 having a small flow path resistance and the absorber 5 and the evaporator. 4, heat exchange with the water supplied from the cold / hot water pipe 21 via the heat transfer tube 21A is condensed, and the water flowing inside the heat transfer tube 21A is heated mainly by the heat of condensation at this time.

The refrigerant condensed by performing the heating action in the evaporator 4 enters the absorber 5 through the refrigerant pipes 17 and 18, evaporates and separates the refrigerant in the high-temperature regenerator 1, and absorbs the refrigerant flowing from the absorption liquid pipe 11. The mixture is mixed with the liquid and 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 pump 13.

Then, the hot water heated by the heat transfer tube 21A inside the evaporator 4 is circulated and supplied to the air-conditioning load (not shown) through the cold / hot water pipe 21 by the operation of the cold / hot water pump 22, thereby performing a heating operation and the like.

It should be noted that even if the cooling water stagnating in the cooling water pipe 23 is heated by the absorber 5, the on-off valve 30
Can be opened to release the pressure.
Pressure does not rise abnormally.

Reference numeral C denotes a controller provided in the double effect absorption refrigerator having the above-described operation functions, which is provided with a microcomputer, a storage means, and the like, and circulates and supplies cold and hot water to an air conditioning load (not shown). The temperature T2 of the cold / hot water flowing out of the heat transfer tube 21A in the evaporator 4 is taken into the cold / hot water pipe 21 from the temperature sensor 32 provided on the outlet side of the evaporator 4 of the cold / hot water pipe 21, and the cold / hot water evaporator outlet is taken out. Conventionally known capacity control for controlling the amount of heat input to the high-temperature regenerator 1 by adjusting the opening of a heating amount control valve (not shown) connected to the heating burner 1B so that the side temperature is maintained at a predetermined set temperature. Has functions.

That is, as the difference between the predetermined set temperature and the temperature T2 of the cold / hot water detected by the temperature sensor 32 increases, the controller C opens the heating amount control valve connected to the heating burner 1B. When the temperature T2 reaches the set temperature, the opening degree of the heating amount control valve is suppressed to the set opening degree, or a control program for performing normal capacity control such as closing is stored in the storage means. ing.

The controller C controls the operation of the absorbent pump 13 so that the level of the absorbent in the high temperature regenerator 1 is maintained at a predetermined level, and the temperature sensor 32 detects the temperature during cooling operation. The temperature T2 of the cold water is equal to the set temperature (for example, 7
A control program for operating the refrigerant pump 19 when the temperature is higher than (° C.) is also provided in the storage means.

The controller C also controls the rotation speed of the cold / hot water pump 22 based on the magnitude of the air-conditioning load, and adjusts the flow rate of the cold / hot water circulated to the air-conditioning load, as shown in FIG. It is provided in storage means.

That is, the absorption type refrigerator has a temperature sensor 31 for detecting the temperature T1 of the cold / hot water flowing back to the evaporator 4 through the cold / hot water pipe 21 after the cooling or heating operation is completed by an air conditioning load (not shown); A pressure sensor 33 for detecting the pressure difference ΔP between the inlet and the outlet of the evaporator 4 of the cold / hot water pipe 21 related to the flow rate of water is further provided. The controller C includes the heating burner 1B, the absorbent pump 13, the refrigerant pump 19 and the like. A control program shown in FIG. 1 is provided, which is configured as a subroutine control of the main control for controlling as described above.

That is, in step S1, the temperature T1 of the cold and hot water flowing back to the evaporator 4 and the temperature T2 of the cold and hot water that has been heated by the heat transfer pipe 21A and flowed out of the evaporator 4 to the cold and hot water pipe 21, The pressure difference ΔP between the entrance and exit of the evaporator 4 of the water pipe 21 is detected.

In step S2, the air conditioning load factor at that time is calculated based on the temperatures T1 and T2 of the cold and hot water detected in step S1 and the pressure difference ΔP.

In step S3, the appropriate flow rate of the chilled and hot water at that time is determined based on the relationship between the preset air conditioning load factor and the flow rate of the cold and hot water, for example, the relational expression shown in FIG. 2 based on the air conditioning load factor calculated in step S2. And the cold and hot water pump 22
To control the flow rate of cold and hot water circulating and supplied to the air conditioning load.

In step S4, the temperature T1 of the cold / hot water flowing back to the evaporator 4 and the temperature of the cold / hot water pipe 2
1 and the temperature T2 of the cold / hot water flowing out for a predetermined time, for example, 5
Detect continuously over minutes.

Then, in step S5, the fluctuation width ΔT of each of the cold and hot water temperatures T1 and T2 detected in step S4.
1, and ΔT2 are determined, each of which is a predetermined temperature, for example, 0.5
It is determined whether the temperature is within ° C or not. If the determination is yes, the process proceeds to step S6. If the determination is no, the process returns to the main control, and after performing required control such as capacity control heating of the heating burner 1B. , The above control from step S1 is repeated.

In step S6, the temperatures T1 and T2 of the cold and hot water detected in step S4 (both may be average values over a predetermined time or may be values at the end of measurement) and rated The correction flow rate of the cold / hot water is calculated from the deviation from the set temperature during operation.

In step S7, the rotational speed of the cold / hot water pump 22 is controlled based on the corrected flow rate of the cold / hot water calculated in step S6, and the flow rate of the cold / hot water circulating to the air conditioning load is corrected. Return to

As a specific example, chilled water of 7 ° C. is circulated and supplied to an air conditioning load (not shown) through a cold / hot water pipe 21, and the cooling water which has cooled the air conditioning load and performed a cooling operation is returned to the evaporator 4 at 12 ° C. An example of adjusting the chilled water flow rate of the absorption chiller having the configuration will be described below.

The temperature T1 of the cold water detected by the temperature sensor 31
Is 10 ° C., the temperature T2 of the cold water detected by the temperature sensor 32 is 7 ° C., the flow rate of the cold water is the rated value, and thus the air-conditioning load factor is 60%. Adjust to 60% of rated operation.

At the time of the partial load operation, the efficiency of the absorption chiller is higher than at the time of the rated operation, so that the average value of the cold water temperature T1 detected by the temperature sensor 31 continuously for, for example, 5 minutes thereafter is calculated. If the average value of the cold water temperature T2 similarly detected is 11.5 ° C. and 7.0 ° C., and the fluctuation range of the cold water temperatures T1 and T2 is within 0.5 ° C., the corrected flow rate of the cold water 60 × 11.5 ÷ 12.0 = 5
It is calculated to be 7.5%, the rotational speed of the cold / hot water pump 23 is corrected, and the flow rate of the cold water circulated to the air conditioning load is corrected to 57.5% of the rated operation.

A cold / hot water pipe 21 is connected to an air conditioning load (not shown).
An example of adjusting the hot water flow rate of an absorption refrigerator having a configuration in which hot water of 55 ° C. is circulated and supplied through the chiller to heat an air-conditioning load and the hot water that has performed a heating action is returned to the evaporator 4 at 50 ° C. explain.

The temperature T1 of the hot water detected by the temperature sensor 31
Is 53 ° C., the temperature T2 of the hot water detected by the temperature sensor 32 is 55 ° C., the flow rate of the hot water is the rated value, and therefore the air-conditioning load factor is 40%. Adjust to 40% of rated operation.

Even during the partial load operation, the efficiency of the absorption chiller is higher than that during the rated operation, so that the average value of the temperature T1 of the hot water detected by the temperature sensor 31 continuously for 5 minutes is 54, for example. 0.0 ° C., the average value of the temperature T2 of the hot water similarly detected is 55.0 ° C., and the fluctuation range of the temperatures T1 and T2 of the hot water both within 0.5 ° C. 40 × 54.0 ÷ 55.0 = 39.3%
Is corrected, and the rotation speed of the cold / hot water pump 23 is corrected, and the flow rate of the hot water circulated to the air conditioning load is set to 39.3 at the rated operation.
Correct to%.

According to the present invention, as described above, the circulation amount of the cold and hot water to the air conditioning load is adjusted according to the air conditioning load, and the flow rate of the cold and hot water is increased by an amount corresponding to the increase in the efficiency during the partial load operation. Since it is reduced, the running cost can be further reduced.

As the controller C, for example, as shown in FIG.
The rotation speed of the cooling water 4 may be controlled to adjust the flow rate of the cooling water supplied to the absorber 5 and the condenser 3.

Even if the flow rate of the cooling water is controlled in this way,
The running cost can be reduced as in the case shown by.

As a specific example, chilled water of 7 ° C. is circulated and supplied to an air conditioning load (not shown) through a cold / hot water pipe 21, and the cooling water that cools the air conditioning load and performs a cooling operation is returned to the evaporator 4 at 12 ° C. An example of adjusting the cooling water flow rate of the absorption chiller having the configuration will be described below.

The temperature T1 of the cold water detected by the temperature sensor 31
For example, if the cooling water temperature T2 detected by the temperature sensor 32 is 7 ° C., the cooling water flow rate is the rated value, and the air conditioning load factor is 60%, the rotation speed of the cooling water pump 23 is controlled to control the cooling water flow rate. Is adjusted to 60% of the rated operation.

Even during this partial load operation, the efficiency of the absorption chiller is higher than during the rated operation, so that the average value of the cold water temperature T1 detected by the temperature sensor 31 for 11 minutes is, for example, 11 minutes. If the average value of the temperature T2 of the chilled water detected in the same manner is 0.5 ° C. and the fluctuation range of the chilled water temperatures T1 and T2 is 0.5 ° C. or less, the corrected flow rate of the chilled water. 60 × 11.5 ÷ 12.0 = 57.5%
And the rotation speed of the cooling water pump 23 is corrected to correct the flow rate of the cooling water circulated to the absorber 5 and the condenser 3 to 57.5% of the rated operation.

Further, as shown in FIG. 4, the lower the temperature of the cooling water flowing into the absorber 5, the more the refrigeration capacity of the absorption refrigerator is exhibited. A temperature sensor 34 is installed in the controller C.
As shown in (2), the rotation speed of the cooling water pump 24 is controlled based on the temperature T3 of the cooling water detected by the temperature sensor 34, and the flow rate of the cooling water supplied to the absorber 5 and the condenser 3 is adjusted. May be.

As a specific example, 7 ° C. cold water is circulated and supplied to an air conditioning load (not shown) through a cold / hot water pipe 21, and the cooling water that cools the air conditioning load and performs a cooling operation is returned to the evaporator 4 at 12 ° C. An example of adjusting the cooling water flow rate of the absorption chiller having the configuration will be described below.

The temperature T of the cooling water detected by the temperature sensor 34
When the temperature of the cooling water detected by the temperature sensor 34 is, for example, 24 ° C.
If this is the case, the number of rotations of the cooling water pump 23 is controlled based on the relational expression between the fuel consumption ratio and the refrigeration capacity ratio for each cooling water temperature, which is determined in detail, to reduce the cooling water flow rate.

When the cooling water temperature is lower than the rated temperature, the efficiency of the absorption chiller is higher than during the rated operation. Therefore, for example, the temperature T1 of the cooling water detected by the temperature sensor 31 continuously for 5 minutes. Is 11.5 ° C., the average value of the similarly detected cold water temperature T2 is 7.0 ° C., and the fluctuation range of the cold water temperatures T1 and T2 during that time is within 0.5 ° C. 10. The corrected flow rate of the cooling water is changed to the flow rate obtained earlier.
The cooling water pump 2 is added to the flow rate obtained by multiplying 5 ÷ 12.0.
The rotation speed of the cooling water 3 is controlled to correct the flow rate of the cooling water circulated to the absorber 5 and the condenser 3.

Even if the flow rate of the cooling water is controlled in this way, the running cost can be reduced as in the case described above.

The control of the flow rate of the cooling water based on the temperature of the cooling water in FIG.
It may be combined with the flow rate control of the cooling water based on the air conditioning load, or may be controlled based on the air conditioning load factor for both the cold / hot water and the cooling water.

The temperatures T1 and T2 of the cold and hot water in step S4 and the like may be detected at predetermined time intervals.

Instead of detecting the pressure difference ΔP between the inlet and the outlet of the evaporator 4 of the cold / hot water pipe 21, the flow rate of the cold / hot water flowing through the cold / hot water pipe 1 is directly detected by a flow meter, and the rotation speed of the cold / hot water pump 22. , And the air conditioning load factor may be calculated.

The magnitude of the air-conditioning load may be calculated by the microcomputer of the controller C as described above, or the temperature difference between the cold / hot water evaporator 4 inlet and outlet and the flow rate of the cold / hot water may be integrated. May be calculated by a calorie meter that calculates the amount of heat.

[0055]

As described above, according to the present invention, during partial load operation with a small heat load, the amount of circulating supply of brine to the heat load, the flow rate of cooling water supplied to the absorber and the condenser, Alternatively, since the flow rates of both of them are reduced, the power cost for transporting the brine and the cooling water can be reduced, thereby reducing the running cost.

According to the fourth aspect of the invention, when the temperature of the cooling water decreases and the capacity of the refrigerator increases, the flow rate of the cooling water decreases, so that the power cost for transporting the cooling water can be reduced. As a result, the running cost can be reduced.

According to the fifth aspect of the present invention, there is no need to write an arithmetic expression for calculating the air conditioning load in a microcomputer incorporated in the controller.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a control method for controlling the flow rate of cold and hot water based on the magnitude of an air conditioning load.

FIG. 2 is an explanatory diagram showing a relationship between an air conditioning load factor and a flow rate of cold and hot water.

FIG. 3 is an explanatory diagram of a control method for controlling a flow rate of cooling water based on a magnitude of an air conditioning load.

FIG. 4 is an explanatory diagram showing a relationship between a fuel consumption ratio and a refrigerating capacity ratio determined for each cooling water temperature.

FIG. 5 is an explanatory diagram of a control method for controlling the flow rate of the cooling water based on the temperature of the cooling water.

FIG. 6 is an explanatory diagram of a device configuration.

[Description of Signs] 1 High temperature regenerator 1B Heating burner 2 Low temperature regenerator 3 Condenser 4 Evaporator 5 Absorber 6 Low temperature heat exchanger 7 High temperature heat exchanger 8-11 Absorbing liquid pipe 13 Absorbing liquid pump 14-18 Refrigerant pipe DESCRIPTION OF SYMBOLS 19 Refrigerant pump 21 Cold / hot water pipe 22 Cold / hot water pump 23 Cooling water pipe 24 Cooling water pump 25/26 Equalization pipe 27-30 Open / close valve 31/32 Temperature sensor 33 Pressure sensor 34 Temperature sensor C controller

Claims (5)

[Claims] 1. A magnitude of a thermal load is determined from a difference in temperature between an inlet and an outlet of a brine that is cooled or heated and circulated to a thermal load, and a thermal operation amount for the brine is controlled based on the magnitude of the thermal load. In the absorption chiller for controlling the amount of circulating brine, when the magnitude of the heat load is less than the rated load, the amount of circulating brine is first controlled based on the ratio of the heat load to the rated load, and the circulating amount is circulated based on the circulating amount. Determining the correction value of the amount of circulating brine based on the difference between the temperature of the entrance and exit of the brine being performed and the set temperature of the entrance and exit of the brine during rated operation, and correcting the amount of circulating brine. Control method of absorption refrigerator. 2. A magnitude of a thermal load is determined from a temperature difference between an inlet and an outlet of the brine which is cooled or heated and circulated to a thermal load, and a thermal operation amount for the brine is controlled based on the magnitude of the thermal load. In an absorption refrigerator controlling the flow rate of cooling water supplied to an absorber and a condenser, when the magnitude of the heat load is less than the rated load, the flow rate of the cooling water is first determined based on a ratio of the heat load to the rated load. Control, and calculates a correction value of the flow rate of the cooling water based on a difference between the temperature of the inlet / outlet section of the brine when the cooling water is set at this flow rate and the set temperature of the inlet / outlet section of the brine during the rated operation. A method for controlling an absorption refrigerator, wherein the flow rate is corrected. 3. The magnitude of the thermal load is determined from the difference in temperature between the inlet and the outlet of the brine, which is cooled or heated and circulated to the thermal load, and the amount of thermal operation on the brine is controlled based on the magnitude of the thermal load. In an absorption refrigerator that controls the circulation amount of brine and the flow rate of cooling water supplied to the absorber and the condenser, when the magnitude of the heat load is less than the rated load, the flow rate of the brine and the cooling water is reduced by the heat load. Is controlled first based on the ratio of the brine to the rated load, and the brine and the coolant are set based on the difference between the temperature of the inlet and outlet of the brine when the flow rate is set to this flow rate and the set temperature of the inlet and outlet of the brine during the rated operation. A method for controlling an absorption refrigerator, wherein a correction value of a flow rate of cooling water is obtained, and a flow rate of brine and cooling water is corrected. 4. An absorption method for determining the magnitude of a heat load from a temperature difference between an inlet and an outlet of a brine which is cooled or heated and circulates and supplies the heat to a heat load, and controlling a heat operation amount for the brine based on the magnitude of the heat load. When the temperature of the cooling water supplied to the absorber and the condenser of the refrigerator is lower than the rated temperature, the flow rate of the cooling water is determined based on the relational expression between the fuel consumption ratio and the refrigerating capacity ratio determined for each cooling water temperature. First, control is performed, and a correction value of the flow rate of the cooling water is obtained based on a difference between the temperature of the inlet / outlet of the brine when the cooling water is set at this flow rate and the set temperature of the inlet / outlet of the brine during the rated operation. A method for controlling an absorption chiller, comprising correcting the flow rate of water. 5. The absorption refrigerator according to claim 1, wherein the magnitude of the heat load is obtained by a calorie meter to which the difference between the temperature of the inlet and the outlet of the brine and the flow rate of the brine are inputted. Control method.