JP2015031440A - Absorption type refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorption type refrigerator capable of improving efficiency by suppressing self-evaporation of a refrigerant from a concentrated solution flowing into an absorber.SOLUTION: An absorption type refrigerator includes a regenerator, a condenser, an evaporator, an absorber, a solution heat exchanger, a refrigerant pump, a concentrated solution pump for supplying a concentrated solution concentrated by the regenerator to the absorber, and a diluted solution pump for supplying a diluted solution diluted by the absorber to the regenerator. A flow rate of the concentrated solution flowing into the absorber is controlled so that a superheating degree of the concentrated solution flowing into the absorber becomes a prescribed value or less. By controlling the superheating degree of the concentrated solution flowing into the absorber to the prescribed value or less, self-evaporation of the refrigerant from the concentrated solution can be suppressed, and thus heat loss by refrigerant vapor is reduced and efficiency of the absorption type refrigerator can be improved.

Description

  The present invention relates to an absorption refrigerator.

  In absorption refrigerators, in order to reduce the amount of heat input to the regenerator, solution heat exchange is performed to exchange heat between a dilute dilute solution at a low temperature in the absorber and a concentrated dilute solution at a high temperature in the regenerator. Equipped with a bowl. In the solution heat exchanger, the amount of heat used only for the temperature rise until the dilute solution having a low concentration is boiled in the regenerator is recovered. At this time, if the state of the cycle changes and heat recovery becomes insufficient, the temperature of the concentrated solution flowing into the absorber becomes a state of superheat higher than the concentrated solution saturation temperature that balances with the pressure in the absorber. When the concentrated solution flowing into the absorber becomes superheated, the refrigerant in the concentrated solution self-evaporates and is absorbed again by the concentrated solution in the absorber, in order to lower the temperature to the concentrated solution saturation temperature. For this reason, the self-evaporated refrigerant becomes a heat loss, which contributes to a decrease in efficiency.

  In addition, in the absorption refrigerator, when the absorber is an air-cooled absorber composed of vertically arranged heat transfer tubes and air-cooled fins, if the concentrated solution flows in with superheat, the refrigerant vapor from the evaporator The self-evaporated refrigerant vapor is added. For this reason, when the inlet flow velocity of the refrigerant vapor into the heat transfer tube increases, the pressure loss in the heat transfer tube also increases, which contributes to a decrease in efficiency.

  In Patent Document 1, in order to suppress the influence of the superheat degree of the concentrated solution flowing into the air-cooled absorber, the concentrated solution is temporarily stored in the air-cooled absorber, and then supplied to the absorption liquid tray. The structure which supplies a concentrated solution to the heat exchanger tube arranged vertically is disclosed. Even if the concentrated solution is superheated by supplying the concentrated solution flowing into the air-cooled absorber to the absorbing solution tray whose upper surface is released once, the refrigerant by self-evaporation from the concentrated solution in the absorbing solution tray The generation of the steam is terminated, and the surface area capable of absorbing the refrigerant vapor in the heat transfer tube is increased.

Japanese Patent Laid-Open No. 10-300268

  As described above, in the absorption refrigerator, the efficiency is further improved by suppressing self-evaporation from the concentrated solution flowing into the absorber. However, in the air-cooled absorber of Patent Document 1, due to the degree of superheat, refrigerant vapor is generated by self-evaporation from the concentrated solution, and flows into the heat transfer tube arranged vertically together with the refrigerant vapor from the evaporator, Pressure loss in the heat pipe will increase.

  An object of the present invention is to provide an absorption refrigerator that suppresses the self-evaporation of the refrigerant from the concentrated solution flowing into the absorber and improves the efficiency.

  The absorption refrigerator of the present invention includes a regenerator, a condenser, an evaporator, an absorber, a solution heat exchanger, a refrigerant pump, a concentrated solution pump for supplying a concentrated solution concentrated in the regenerator to the absorber, and absorption. Equipped with a dilute solution pump for supplying the dilute solution diluted in the vessel to the regenerator, and the flow rate of the concentrated solution flowing into the absorber is adjusted so that the superheat degree of the concentrated solution flowing into the absorber is below a predetermined value. Control.

  According to the present invention, it is possible to suppress the self-evaporation of the refrigerant from the concentrated solution by suppressing the degree of superheat of the concentrated solution flowing into the absorber to a predetermined value or less, thereby reducing the heat loss due to the refrigerant vapor, The efficiency of the absorption refrigerator can be improved.

Cycle system diagram of absorption refrigerator of Example 1 Cycle system diagram of absorption refrigerator of Example 2 Cycle system diagram of the absorption refrigerator of Example 3

  The absorption refrigerator of the present embodiment includes a regenerator, a condenser, an evaporator, an absorber, a solution heat exchanger, a refrigerant pump, a concentrated solution pump for supplying a concentrated solution concentrated in the regenerator to the absorber, A dilute solution pump for supplying the dilute solution diluted in the absorber to the regenerator is provided, and the flow rate of the concentrated solution flowing into the absorber so that the superheat degree of the concentrated solution flowing into the absorber is below a predetermined value. To control. According to the absorption refrigerator of the present embodiment, the self-evaporation of the refrigerant from the concentrated solution can be suppressed by suppressing the superheat degree of the concentrated solution flowing into the absorber to a predetermined value or less. Heat loss can be reduced and the efficiency of the absorption refrigerator can be improved. In the case of an air-cooled absorber composed of vertically arranged heat transfer tubes and air-cooling fins, almost the entire amount of refrigerant vapor flowing into the heat transfer tubes can be used as refrigerant vapor from the evaporator. The generated pressure loss can be minimized, and the efficiency can be further improved.

  A first embodiment of the absorption refrigerator according to the present invention will be described with reference to FIG. FIG. 1 is a cycle system diagram showing Embodiment 1 of the present invention.

  The overall configuration of the first embodiment will be described with reference to FIG. The absorption refrigerator includes a regenerator 1, an air-cooled condenser 3, an evaporator 6, an air-cooled absorber 3, a solution heat exchanger 7, a concentrated solution pump 8, a diluted solution pump 9, a refrigerant pump 10, and the like.

  The regenerator 1 is comprised of a heat exchanger 1b composed of a spreading device 1a and a plurality of heat transfer tubes. A heat source medium supplied from the heat source through the heat medium pipe 1c flows in the heat exchanger 1b. A dilute solution having a low concentration is sprayed from the spraying device 1a toward the heat exchanger 1b. The dilute solution flowing outside the heat transfer tube constituting the heat exchanger 1b is heated by a heating source medium to generate refrigerant vapor, and the dilute solution is concentrated to a concentrated solution to be regenerated.

  For example, 90 ° C. warm water is supplied to the regenerator 1 as a heating source medium, and the hot water is cooled to 85 ° C. by heating the dilute solution flowing outside the heat transfer tube of the heat exchanger 1b. On the other hand, the refrigerant vapor generated by heating and concentrating the dilute solution flows into the air-cooled condenser 3. The upper header 3 a of the air-cooled condenser 3 is connected to the regenerator 1 by the refrigerant vapor pipe 2.

  The air-cooled condenser 3 includes an upper header 3a, an air-cooling heat exchanger 3b composed of heat transfer tubes and air-cooling fins, and a lower header 3c. Refrigerant vapor from the regenerator 1 is guided to the upper header 3 a of the air-cooled condenser 3 through the refrigerant vapor pipe 2. In the air-cooled heat exchanger 3b, the refrigerant vapor in the heat transfer tube is cooled by the cooling air flowing outside the heat transfer tube, condensates and becomes liquid refrigerant (water).

  The liquid refrigerant condensed and liquefied by the air-cooled condenser 3 passes through the refrigerant pipe 13 and is led to the evaporator 6.

  The evaporator 6 includes a spraying device 6a and a heat exchanger 6b including a plurality of heat transfer tubes. The liquid refrigerant guided to the evaporator 6 flows through the refrigerant pipe 14 by the refrigerant pump 10, is guided to the spraying device 6a of the evaporator 6, and is sprayed outside the heat transfer tube of the heat exchanger 6b.

  The cold water is passed from the cold water pipe 6 c to the heat exchanger 6 b of the evaporator 6. The cold water heats the liquid refrigerant flowing outside the heat transfer tube of the heat exchanger 6b of the evaporator 6 to generate refrigerant vapor, and is cooled by using latent heat of evaporation at this time. The cold water is used for cooling or the like by supplying it to a fan coil unit or the like disposed indoors as cold heat.

  On the other hand, the concentrated solution concentrated in the regenerator 1 is guided to the air-cooled absorber 4 after passing through the solution heat exchanger 7 by the concentrated solution pump 8 and the solution pipe 11. The air-cooled absorber 4 includes an upper header 4a, a spreading device 4b, an air-cooled heat exchanger 4c, and a lower header 4d. The air-cooling heat exchanger 4c is composed of heat transfer tubes and air-cooling fins arranged vertically. The concentrated solution from the regenerator 1 flows down in the heat transfer tube of the air-cooled heat exchanger 4c via the spraying device 4b provided in the upper header 4a of the air-cooled absorber 4, and is guided to the lower header 4d.

  The refrigerant vapor from the evaporator 6 is supplied to the upper header 4 a via the refrigerant vapor pipe 5. The refrigerant vapor guided to the upper header 4a is guided to the air-cooling heat exchanger 4c and absorbed by the concentrated solution flowing down in the heat transfer tube of the air-cooling heat exchanger 4c. The absorption heat generated when the concentrated solution absorbs the refrigerant vapor is transmitted to the cooling air that is ventilated outside the heat transfer tube of the air cooling heat exchanger 4c by an air cooling fan (not shown) via the air cooling fins, to the outside air. Released.

  The dilute solution in the lower header 4 d of the air-cooled absorber 4 is guided by the dilute solution pump 9 to the spraying device 1 a of the regenerator 1 after passing through the solution heat exchanger 7 via the solution pipe 12. In the solution heat exchanger 7, the hot concentrated solution from the regenerator 1 exchanges heat with the low temperature dilute solution from the air-cooled absorber 4, and the sensible heat of the high temperature concentrated solution is recovered, and the temperature of the low temperature dilute solution is recovered. Used for climbing.

  In this embodiment, lithium bromide is used as the solution (absorbent), and water is used as the refrigerant.

  Next, a method for controlling the rotational speed of the concentrated solution pump 8 based on the degree of superheat will be described.

  The degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is provided in the T2 temperature sensor 16 provided in the solution pipe 11 serving as the inlet of the concentrated solution of the air-cooled absorber 4 and in the spraying device 4b of the air-cooled absorber 4. Calculated by the difference from the T1 temperature sensor 15. The T2 temperature sensor 16 detects the temperature T2 of the concentrated solution flowing into the air-cooled absorber 4. The T1 temperature sensor 15 detects the saturation temperature T1 of the concentrated solution of the spraying device 4b of the air-cooled absorber 4. The degree of superheat is calculated as (T2-T1) by the control device 17. The spraying device 4b of the air-cooled absorber 4 has a gas phase portion communicating with the gas phase portion in the upper header 4a, so that the concentrated solution supplied to the spraying device 4b has a saturation temperature that balances with the pressure in the upper header 4a. It becomes. Therefore, the degree of superheat can be calculated from the difference between the temperature T1 of the concentrated solution in the spraying device 4b detected by the T1 temperature sensor 15 and the temperature T2 detected by the T2 temperature sensor 16.

  In the solution heat exchanger 7, when the recovery of the thermal energy of the concentrated solution from the regenerator 1 becomes insufficient due to the diluted solution from the air-cooled absorber 4, the temperature of the concentrated solution is not lowered and the superheated state The air-cooled absorber 4 flows into the spraying device 4b in the upper header 4a. Specifically, the pressure difference between the evaporator 6 and the air-cooled absorber 4 on the low pressure side and the condenser 3 and the regenerator 1 side on the high pressure side becomes large, and the rotational speed of the dilute solution pump 9 and the concentrated solution pump If the rotational speed of 8 is maintained as it is, the flow rate on the dilute solution side decreases and the flow rate on the concentrated solution side increases, thereby causing superheat to the solution flowing into the air-cooled absorber 4. Such a degree of superheat occurs when the temperature of the heating source medium or the temperature of the cooling air rises with respect to the rated operating state.

  Therefore, the number of rotations of the dilute solution pump 9 is fixed, and the degree of superheat of the solution flowing into the air-cooled absorber 4 at a constant cycle is calculated by the control device 17 to which the T1 temperature sensor 15 and the T2 temperature sensor 16 are connected. When the superheat degree is higher than the first predetermined value, the rotational speed of the concentrated solution pump 8 connected to the control device 17 is controlled to be lower (concentrated solution). Reduce the rotational speed of the pump 8). When the degree of superheat is higher than the first predetermined value, the flow rate of the concentrated solution from the regenerator 1 is decreased, thereby reducing the exchange heat amount on the concentrated solution side and reducing the inlet / outlet temperature difference in the solution heat exchanger 7. Since it is possible, the degree of superheat can be gradually reduced. Furthermore, the imbalance between the flow rates of the dilute solution and the concentrated solution can be eliminated.

  On the other hand, when the operating state where the pressure difference between the low pressure side and the high pressure side is large is returned to the rated operating state, or when the evaporator 6 and air cooling absorber 4 on the low pressure side and the condenser 3 and regenerator 1 side on the high pressure side are connected. When the pressure difference becomes small, the flow rate on the concentrated solution side decreases and the flow rate on the dilute solution side increases. As a result, the amount of heat that can be recovered with the dilute solution increases, so that the temperature of the concentrated solution decreases sufficiently and flows into the spraying device 4b in the upper header 4a of the air-cooled absorber 4. Thereby, when the superheat degree becomes smaller than the first predetermined value, the rotational speed of the concentrated solution pump 8 connected to the control device 17 is controlled to be higher (the rotational speed of the concentrated solution pump 8 is increased). .

  The first predetermined value may be obtained in advance from various conditions, or may be calculated by the control device 17 each time during operation. The same applies to other predetermined values.

  In the operating state in which the degree of superheat is smaller than the first predetermined value, the air-cooled absorber 4 can reduce the heat loss due to the degree of superheat, but the reduction in the heat transfer coefficient in the pipe due to the decrease in the amount of concentrated solution sprayed, Since the flow rate of the solution is unbalanced, the absorption refrigerator can be operated continuously and efficiently by controlling the rotational speed of the concentrated solution pump 8 so that the degree of superheat of the first predetermined value is obtained. it can.

  As described above, by controlling the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4, heat loss can be reduced and the balance between the flow rate of the diluted solution and the concentrated solution can be improved, and efficient operation is possible. It becomes.

  A second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a cycle system diagram showing Embodiment 2 of the present invention. In this embodiment, the means for detecting the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is different from that in the first embodiment. Hereinafter, a configuration different from that of the first embodiment will be described.

  A P1 pressure sensor 20 is provided in the evaporator 6, a P2 pressure sensor 21 is provided in the air-cooled condenser 3, and a T3 temperature sensor 22 is provided in the solution pipe 11 at the concentrated solution outlet of the regenerator 1, and each is connected to the control device 17.

  Similar to the first embodiment, the T2 temperature sensor 16 detects the temperature T2 of the concentrated solution flowing into the air-cooled absorber 4. The T3 temperature sensor 22 detects the temperature T3 of the concentrated solution flowing out from the regenerator 1. The P1 pressure sensor 20 detects the saturation pressure P1 of the refrigerant in the evaporator. The P2 pressure sensor 21 detects the saturation pressure P2 of the refrigerant in the condenser.

  Here, the solution concentration can be calculated as a function of the solution saturation temperature and pressure (water saturation temperature), and the solution saturation temperature can be calculated as a function of the solution concentration and pressure (water saturation temperature). . Therefore, the superheat degree of the concentrated solution flowing into the air-cooled absorber 4 is calculated by the following procedure.

  (1) The temperature T3 of the concentrated solution flowing out from the regenerator detected by the T3 temperature sensor 22 is set as the solution saturation temperature at the outlet of the regenerator 1, and the saturation pressure P2 of the refrigerant in the air-cooled condenser detected by the P2 pressure sensor 21 From this, the concentration of the concentrated solution flowing into the air-cooled absorber 4 is calculated. The T3 temperature sensor 22 for detecting the temperature T3 of the “concentrated solution flowing out from the regenerator” may measure the temperature of the concentrated solution after flowing out from the regenerator as long as it can be detected as the solution saturation temperature. The temperature of the concentrated solution before flowing out of the regenerator (for example, when the concentrated solution is accumulated in the lower part of the regenerator 1), the temperature of the concentrated solution may be measured. The same applies to other temperature sensors.

  (2) The concentrated solution saturation temperature flowing into the air-cooled absorber 4 is calculated from the concentrated solution concentration in (1) and the saturation pressure P1 of the refrigerant in the evaporator detected by the P1 pressure sensor 20.

  (3) The degree of superheat is calculated from the difference between the concentrated solution saturation temperature of (2) and the temperature T2 of the concentrated solution flowing into the air-cooled absorber 4 detected by the T2 temperature sensor 16.

  (4) In the control device 17, (1) to (3) are performed at regular intervals, and the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is calculated. Based on the calculated degree of superheat, the rotational speed of the dilute solution pump 9 is fixed and the rotational speed of the concentrated solution pump 8 is controlled.

  In this embodiment, the means for detecting the saturation temperature of the concentrated solution flowing into the air-cooled absorber 4 is different from that of the first embodiment, but the concentration of the concentrated solution pump 8 based on the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is different. With respect to the method for controlling the rotational speed, the same effect as in the first embodiment can be obtained by performing the same as in the first embodiment.

  Further, as shown in (1), the temperature T3 of the concentrated solution flowing out from the regenerator 1 detected by the T3 temperature sensor 22 is set as the solution saturation temperature at the outlet of the regenerator 1, and the air-cooled condenser detected by the P2 pressure sensor 21. Since the concentration of the concentrated solution flowing into the air-cooled absorber 4 is calculated from the saturation pressure P2 of the refrigerant inside, when the concentration of the concentrated solution exceeds a second predetermined value, the amount of heat input to the regenerator 1 is calculated. By controlling the flow rate of the heating source medium so as to decrease, crystallization of the concentrated solution can be prevented. Further, since the refrigerant temperature in the evaporator 6 is calculated from the saturation pressure P1 of the refrigerant in the evaporator detected by the P1 pressure sensor 20 of the evaporator 6, when the refrigerant temperature becomes lower than the third predetermined value, By controlling the flow rate of the heating source medium so as to reduce the amount of heat input to the regenerator 1, it is possible to prevent the refrigerant from freezing.

  A third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cycle system diagram showing Embodiment 3 of the present invention. In this embodiment, the means for detecting the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is different from that in the first embodiment. Hereinafter, a configuration different from that of the first embodiment will be described.

  A T3 temperature sensor 22 is provided in the solution pipe 11 at the concentrated solution outlet of the regenerator 1, a T4 temperature sensor 31 is provided in the refrigerant pipe 13 at the refrigerant outlet of the air-cooled condenser 3, and a T5 temperature is provided in the refrigerant pipe 14 at the refrigerant outlet of the evaporator 6. Sensors 32 are provided and each is connected to the control device 17.

  Similar to the first embodiment, the T2 temperature sensor 16 detects the temperature T2 of the concentrated solution flowing into the air-cooled absorber 4. The T3 temperature sensor 22 detects the temperature T3 of the concentrated solution flowing out from the regenerator 1. The T4 temperature sensor 31 detects the temperature T4 of the refrigerant flowing out from the air-cooled condenser 3. The T5 temperature sensor 31 detects the temperature T5 of the refrigerant flowing out of the evaporator 6.

  Here, the solution concentration can be calculated as a function of the solution saturation temperature and pressure (water saturation temperature), and the solution saturation temperature can be calculated as a function of the solution concentration and pressure (water saturation temperature). . Therefore, the superheat degree of the concentrated solution flowing into the air-cooled absorber 4 is calculated by the following procedure.

  (1) The temperature T3 of the concentrated solution flowing out of the regenerator detected by the T3 temperature sensor 22 is set as the solution saturation temperature at the outlet of the regenerator 1, and the temperature of the refrigerant flowing out of the air-cooled condenser 3 detected by the T4 temperature sensor 31 From T4, the concentration of the concentrated solution flowing into the air-cooled absorber 4 is calculated.

  (2) The concentrated solution saturation temperature flowing into the air-cooled absorber 4 is calculated from the concentrated solution concentration in (1) and the temperature T5 of the refrigerant flowing out from the evaporator 6 detected by the T5 temperature sensor 32.

  (3) The degree of superheat is calculated from the difference between the concentrated solution saturation temperature of (2) and the temperature T2 of the concentrated solution flowing into the air-cooled absorber 4 detected by the T2 temperature sensor 16.

  (4) In the control device 17, (1) to (3) are performed at regular intervals, and the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is calculated. Based on the calculated degree of superheat, the rotational speed of the dilute solution pump 9 is fixed and the rotational speed of the concentrated solution pump 8 is controlled.

  In this embodiment, the means for detecting the saturation temperature of the concentrated solution flowing into the air-cooled absorber 4 is different from that of the first embodiment, but the concentration of the concentrated solution pump 8 based on the degree of superheat of the concentrated solution flowing into the air-cooled absorber 4 is different. About the control method of rotation speed, the same effect can be acquired by carrying out similarly to Example 1. FIG.

  Further, as shown in (1), the temperature T3 of the concentrated solution flowing out from the regenerator 1 detected by the T3 temperature sensor 22 is set as the solution saturation temperature at the outlet of the regenerator 1, and the air-cooled condenser detected by the T4 temperature sensor 31. Since the concentration of the concentrated solution flowing into the air-cooled absorber 4 is calculated from the temperature T4 of the refrigerant flowing out from 3, the amount of heat input to the regenerator 1 is calculated when the concentrated solution concentration exceeds the second predetermined value. By controlling the flow rate of the heating source medium so as to decrease, crystallization of the concentrated solution can be prevented. Further, when the temperature T5 of the refrigerant flowing out of the evaporator 6 detected by the T5 temperature sensor 32 of the evaporator 6 becomes lower than the third predetermined value, heating is performed so as to reduce the heat input to the regenerator 1. By controlling the flow rate of the source medium, it is possible to prevent the refrigerant from freezing.

  Therefore, according to the present Example, the efficient absorption refrigerator which suppressed the heat loss can be obtained.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, although the flow rate flowing into the air-cooled absorber 4 is controlled by the concentrated solution pump 8, the solution pipe 11 is provided with a flow rate adjustment valve (not shown) as a control target, and the opening degree is adjusted by the control device 17. It can also be applied to refrigerators. Further, in the present invention, the air-cooled absorber 4 and the air-cooled condenser 3 including the heat transfer tubes and the air-cooled fins in which the absorber and the condenser are arranged vertically are used, but the water cooling in which the cooling water flows through the tubes of the horizontally arranged heat transfer tubes. It can also be applied to absorbers and condensers of the type. Further, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

DESCRIPTION OF SYMBOLS 1: Regenerator, 1a: Spreading device, 1b: Heat exchanger, 1c: Heating medium piping 2, 5: Refrigerant vapor piping 3: Air cooling condenser, 3a: Upper header, 3b: Air cooling heat exchanger, 3c: Lower header 4: Air-cooled absorber, 4a: Upper header, 4b: Spraying device, 4c: Air-cooled heat exchanger, 4d Lower header 6: Evaporator, 6a: Spraying device, 6b: Heat exchanger, 6c: Cold water piping 7: Solution heat Exchanger 8: Concentrated solution pump 9: Dilute solution pump 10: Refrigerant pump 11, 12: Solution pipe 13, 14: Refrigerant pipe 15: T1 temperature sensor 16: T2 temperature sensor 17: Controller 20: P1 pressure sensor 21: P2 Pressure sensor 22: T3 temperature sensor 31: T4 temperature sensor 32: T5 temperature sensor

Claims (9)

Regenerator, condenser, evaporator, absorber, solution heat exchanger, refrigerant pump, concentrated solution pump for supplying concentrated solution concentrated in the regenerator to the absorber, diluted diluted in the absorber A dilute solution pump for supplying solution to the regenerator,
An absorption refrigerator that controls the flow rate of the concentrated solution flowing into the absorber so that the degree of superheat of the concentrated solution flowing into the absorber becomes a first predetermined value or less. In claim 1,
Absorber solution temperature detecting means for detecting the temperature of the concentrated solution flowing into the absorber;
Solution saturation temperature detection means for detecting the saturation temperature of the concentrated solution in the absorber spraying device;
A controller for calculating the degree of superheat and controlling the number of revolutions of the concentrated solution pump,
The control device calculates the degree of superheat from the detection results of the absorber solution temperature detecting means and the solution saturation temperature detecting means, and the number of rotations of the concentrated solution pump so that the degree of superheat is equal to or less than the first predetermined value. Absorption type refrigerator that controls. In claim 1,
Absorber solution temperature detecting means for detecting the temperature of the concentrated solution flowing into the absorber;
Evaporating pressure detecting means for detecting the saturation pressure of the refrigerant in the evaporator;
Condensation pressure detection means for detecting the saturation pressure of the refrigerant in the condenser;
Regenerator solution temperature detecting means for detecting the temperature of the concentrated solution flowing out of the regenerator,
A controller for calculating the degree of superheat and controlling the number of revolutions of the concentrated solution pump,
The controller calculates the degree of superheat from detection results of the absorber solution temperature detection means, the evaporation pressure detection means, the condensation pressure detection means, and the regenerator solution temperature detection means, and the degree of superheat is An absorption refrigerator that controls the number of revolutions of the concentrated solution pump to be equal to or lower than a first predetermined value. In claim 3,
The controller is
From the detection results of the condensation pressure detection means and the regenerator solution temperature detection means, the concentration of the concentrated solution flowing into the absorber is calculated, and when the concentration of the concentrated solution exceeds a second predetermined value Reducing the heat input to the regenerator,
From the detection result of the evaporating pressure detecting means, the temperature of the refrigerant in the evaporator is calculated, and when the temperature of the refrigerant becomes lower than a third predetermined value, absorption that reduces the heat input to the regenerator Type refrigerator. In claim 1,
Absorber solution temperature detecting means for detecting the temperature of the concentrated solution flowing into the absorber;
Evaporator temperature detection means for detecting the temperature of the refrigerant flowing out of the evaporator;
Condenser refrigerant temperature detection means for detecting the temperature of the refrigerant flowing out of the condenser;
Regenerator solution temperature detecting means for detecting the temperature of the concentrated solution flowing out of the regenerator,
A controller for calculating the degree of superheat and controlling the number of revolutions of the concentrated solution pump,
The superheat degree is calculated from the detection results of the absorber solution temperature detection means, the evaporator refrigerant temperature detection means, the condenser refrigerant temperature detection means, and the regenerator solution temperature detection means, and the superheat degree is the first value. An absorption refrigerator that controls the number of revolutions of the concentrated solution pump to be equal to or less than a predetermined value. In claim 5,
The control means includes
When the concentration of the concentrated solution flowing into the absorber is calculated from the detection results of the condenser refrigerant temperature detection means and the regenerator solution temperature detection means, and the concentration of the concentrated solution exceeds a second predetermined value In order to reduce the heat input to the regenerator,
The temperature of the refrigerant in the evaporator is calculated from the detection result of the evaporator refrigerant temperature detecting means, and when the refrigerant temperature becomes lower than a third predetermined value, the amount of heat input to the regenerator is reduced. Absorption type refrigerator. In any of claims 2 to 6,
The control device decreases the rotational speed of the concentrated solution pump when the calculated degree of superheat is higher than the first predetermined value, and when the calculated degree of superheat is lower than the first predetermined value. An absorption refrigerator that increases the rotational speed of the concentrated solution pump. In any one of Claims 1 thru | or 7,
The absorber has an air-cooled heat exchanger composed of vertically arranged heat transfer tubes and air-cooling fins,
The air-cooled heat exchanger is an absorption refrigerator disposed between an upper header into which refrigerant vapor from the evaporator and a concentrated solution from the regenerator flow and a lower header in which a diluted solution is stored.   9. The absorption refrigerator according to claim 1, wherein the number of revolutions of the dilute solution pump is fixed.