JP3086594B2 - Single double effect absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator, and more particularly to a single-double effect absorption refrigerator having a low heat source regenerator and a low heat source regenerator condenser body containing a condenser.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Patent Publication No. 4-260760 discloses an evaporator absorber body containing an evaporator and an absorber, a low-temperature regenerator condenser body containing a low-temperature regenerator and a condenser, and a temperature controller. A low-heat-source regenerator housing a condenser with a low-heat-source regenerator that uses wastewater as a low-temperature heat source and a condenser body, and a single-double-effect absorption type in which a high-temperature regenerator is connected by piping to form a circulation path for the absorbent and refrigerant. A refrigerator is disclosed.

As a method of controlling a single-double-effect absorption refrigerator, there is, for example, Japanese Patent Application No. 5-130686. These controls are for keeping the outlet temperature of the cold water taken out of the evaporator constant. For this reason, there is a tendency that the temperature of the low-temperature heat source that returns after working with the low-heat-source regenerator decreases as the load of the chilled water increases. For this reason, for example, when using cooling water such as a generator as a low-temperature heat source, when the temperature of the low-temperature heat source returning to the generator is significantly reduced,
There is a possibility that dew condensation will occur and a trouble will occur in the generator. Therefore, as shown in FIG. 5, a temperature sensor S1, a controller C1, and a flow control valve (three-way valve) 29E are provided to control the flow to the low heat source heat exchanger 29B according to the chilled water outlet temperature. A temperature sensor S5, a controller C4, and a flow control valve (three-way valve) 29F are provided on the equipment side so that the return temperature of the low-temperature heat source becomes constant. The temperature sensor S5 is supplied from a low-heat-source supply pipe 29A, and the low-heat-source heat exchanger 29B is provided. The temperature is controlled so that the return temperature of the low-temperature heat source returning through the low-heat-source return pipe 29C becomes constant.

In FIG. 5, 1 is an evaporator, 2 is an absorber, 4 is a high temperature regenerator, 6 is a low temperature regenerator, 9 is a low heat source regenerator, 7 and 10 are condensers, and 12 is low temperature heat exchange. , 13 is a high-temperature heat exchanger, P1 is a rare absorbing liquid pump, P2 is an intermediate absorbing liquid pump, P3 is a refrigerant liquid pump, C1, C2, C
3 and C4 are controllers.

[0005]

In the conventional single-double-effect absorption refrigerator described above, in order to control the supply amount of the low-temperature heat source, valves such as expensive three-way valves are required in duplicate. Therefore, there is a problem to be solved from the viewpoint of cost reduction.

[0006]

According to the first aspect of the present invention, there is provided an evaporator absorber body containing an evaporator and an absorber, and a low-temperature regenerator. Low-temperature regenerator condenser body containing condenser, low-heat-source regenerator condenser body containing low-temperature heat source that uses hot wastewater as low-temperature heat source and condenser And forming a circulation path of the refrigerant, providing a three-way valve so as to communicate the supply pipe and the return pipe of the low-temperature heat source, while controlling the heating amount of the high-temperature regenerator based on the outlet temperature of the cold water taken out from the evaporator, The three-way valve is controlled based on the outlet temperature of the chilled water, and when the return temperature of the low-temperature heat source falls below a predetermined temperature,
An object of the present invention is to provide a single double effect absorption refrigerator provided with a controller for increasing a set value of a chilled water outlet temperature for controlling a three-way valve.

According to the second aspect of the present invention, an evaporator absorber body containing an evaporator and an absorber, a low temperature regenerator condenser body containing a low temperature regenerator and a condenser, A low-heat-source regenerator containing a condenser and a low-heat-source regenerator containing wastewater etc. as a low-temperature heat source, and a high-temperature regenerator connected by piping to form a circulation path for the absorbent and refrigerant, and a supply pipe for the low-temperature heat source A three-way valve is provided so as to communicate with the return pipe, and the heating amount of the high-temperature regenerator is controlled based on the outlet temperature of the cold water taken out from the evaporator, and the three-way valve is controlled based on the outlet temperature of the cold water, and Another object of the present invention is to provide a single-double-effect absorption refrigerator provided with a controller for gradually increasing a set value of a chilled water outlet temperature for controlling a three-way valve as a return temperature of a low-temperature heat source becomes lower than a predetermined temperature.

According to the third aspect of the present invention, an evaporator absorber body containing an evaporator and an absorber, a low temperature regenerator condenser body containing a low temperature regenerator and a condenser, A low-heat-source regenerator containing a condenser and a low-heat-source regenerator containing wastewater etc. as a low-temperature heat source, and a high-temperature regenerator connected by piping to form a circulation path for the absorbent and refrigerant, and a supply pipe for the low-temperature heat source A three-way valve is provided so as to communicate with the return pipe, and the heating amount of the high-temperature regenerator is controlled based on the outlet temperature of the cold water taken out from the evaporator, and the three-way valve is controlled based on the outlet temperature of the cold water, and When the return temperature of the low-temperature heat source falls below a predetermined temperature, a single-double-effect absorption refrigerator provided with a controller for reducing the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator in accordance with the decrease is provided. It is.

[0009]

According to the first aspect of the present invention, the amount of heating of the high-temperature regenerator and the three-way valve are controlled based on the outlet temperature of the cold water taken out of the evaporator. The outlet temperature of the chilled water can be maintained at the set value regardless of the increase / decrease of the low-temperature heat source supplied to the vessel and the fluctuation of the load.

When the return temperature of the low-temperature heat source decreases due to a change in load or the like, the set value of the outlet temperature of the chilled water is increased, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator is reduced, and the return of the low-temperature heat source is reduced. The temperature can be maintained at a specified temperature or higher, and even if the cooling water of the generator is used as a low-temperature heat source, troubles such as condensation forming when the generator is cooled by the low-temperature heat source whose temperature has dropped significantly will occur. Can be avoided.

Furthermore, such an excellent operation and effect can be obtained by operating one three-way valve, and it is possible to provide a single-double-effect absorption refrigerator which is excellent in cost. . According to the second aspect of the invention, when the return temperature of the low-temperature heat source decreases, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator is gradually reduced in accordance with the degree of the decrease, and the discharge in the low-temperature heat source regenerator is reduced. Gradually reduce the amount of heat,
Responsiveness to load fluctuations can be improved, and the return temperature of the low-temperature heat source can be maintained at a predetermined temperature or higher.When the cooling water of the generator is used as the low-temperature heat source, the return temperature of the low-temperature heat source decreases. In this case as well, while effectively utilizing the low-temperature heat source, it is possible to avoid such a trouble that dew condensation occurs when the generator is cooled by the low-temperature heat source whose temperature has significantly decreased.

Further, it is possible to prevent the regeneration temperature of the low heat source regenerator from being extremely lowered, and to effectively utilize the heat of the low temperature heat source even when the amount of heat of the low temperature heat source changes, so that the regeneration of the refrigerant is effective. It is possible to improve the COP. According to the invention of claim 3, the heating amount of the high-temperature regenerator and the three-way valve are controlled based on the outlet temperature of the cold water taken out of the evaporator, and when the return temperature of the low-temperature heat source falls below a predetermined temperature, With this decrease, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator is reduced, and the outlet temperature of the cold water is maintained at the set value regardless of the variation of the low-temperature heat source supplied to the low heat source regenerator and the load, When the return temperature of the low-temperature heat source decreases, the amount of low-temperature heat source that flows into the low-temperature heat source regenerator is reduced, and the amount of heat released by the low-temperature heat source regenerator is improved. And the return temperature of the low-temperature heat source can be maintained at a predetermined temperature or higher.Even when the cooling water of the generator is used as the low-temperature heat source, the generator is cooled by the low-temperature heat source whose temperature has dropped significantly. Condensation when you do It becomes possible to avoid the trouble, such as say that.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows that the refrigerant is, for example, water and an absorbing liquid (solution).
1 is a schematic configuration diagram of a single-double effect absorption refrigerator using a lithium bromide (LiBr) solution as an example, 1 is an evaporator, 2 is an absorber, 3 is an evaporator containing an evaporator 1 and an absorber 2 An absorber cylinder (hereinafter, referred to as a lower cylinder), 4 is a high-temperature regenerator equipped with, for example, a gas burner 5 and heated by a high-temperature heat source, 5A is a fuel control valve for adjusting the amount of gas supplied to the gas burner 5, and 6 is a low-temperature A regenerator 7 is a condenser for the low-temperature regenerator 6 (hereinafter, referred to as a first condenser), and 8 is a low-temperature regenerator condenser body (hereinafter, referred to as a first condenser) housing the low-temperature regenerator 6 and the first condenser 7. 1
A lower heat source regenerator 9 using, for example, warm wastewater of about 95 ° C. as a low temperature heat source; 10 a condenser for the low temperature heat source regenerator 9 (hereinafter referred to as a second condenser); A low heat source regenerator condenser body (hereinafter, referred to as a second upper body) containing the low heat source regenerator 9 and the second condenser 10, a low temperature heat exchanger 12;
13 is a high-temperature heat exchanger.

Reference numeral 2A denotes a rare absorbing liquid reservoir formed below the absorber 2, and the rare absorbing liquid reservoir 2A and the low heat source regenerator 9
Is connected to the gas phase section by a dilute absorbent pipe 14 provided with a dilute absorbent pump P1 on the way. Further, the intermediate absorbent reservoir 9A formed at the lower portion of the low heat source regenerator 9 and the gas phase of the high temperature regenerator 4 are connected between the intermediate absorbent pump P2
Are connected by an intermediate absorption liquid pipe 15 having

Reference numeral 4A denotes an intermediate absorbing liquid reservoir formed in the high-temperature regenerator 4;
The pipe is connected to the gas phase by an intermediate absorbent pipe 16. Further, the concentrated absorption liquid reservoir 6A formed in the lower part of the low temperature regenerator 6 and the concentrated absorption liquid spraying device 2B provided in the gas phase part of the absorber 2 are composed of concentrated absorption liquid pipes 17A and 17B. 17 is connected by piping.

The intermediate absorption liquid pipe 15A on the suction side of the intermediate absorption liquid pump P2 and the concentrated absorption liquid pipe 17A on the upstream side of the low-temperature heat exchanger 12 are connected by an absorption liquid pipe 18. The absorption liquid pipe 18 is provided at a position lower than the first upper body 8, and even if a difference occurs between the pressure in the second upper body 11 and the pressure in the first upper body 8, the absorption liquid pipe 18 is provided between each body. Is sealed with an absorbing liquid.

The intermediate absorbent pipe 16A on the upstream side of the high-temperature heat exchanger 13 and the absorber 2 are connected by an intermediate absorbent pipe 19 provided with an on-off valve 10V in the middle.
The on-off valve 19V is closed when cold water is supplied, and is opened when hot water is supplied. Reference numeral 20 denotes a refrigerant vapor pipe extending from the gas phase portion of the high-temperature regenerator 4 to the first upper body 8, and opens to the bottom of the first condenser 7 via the inside of the low-temperature regenerator 6. 21
Is a refrigerant vapor pipe provided with an on-off valve 21V in the middle and communicating the refrigerant vapor pipe 21A on the upstream side of the low temperature regenerator 6 with the gas phase of the absorber 2. The on-off valve 21V is closed when cold water is supplied, and is opened when hot water is supplied.

Reference numeral 22 denotes a first refrigerant liquid pipe connecting the bottom of the first condenser 7 and the gas phase of the evaporator 1.
A U-seal portion 22 </ b> A is formed in the middle of the refrigerant liquid pipe 22. Reference numeral 23 denotes a second refrigerant liquid pipe that connects the bottom of the second condenser 10 to the U seal portion 22A of the first refrigerant liquid pipe 22. The second refrigerant liquid pipe 23 also has a first refrigerant liquid pipe. A U-seal portion 23 </ b> A is formed at a connection portion with the 22.

Reference numeral 24 denotes a refrigerant liquid circulation pipe for connecting the refrigerant liquid reservoir 1A of the evaporator 1 to the refrigerant dispersion device 1B, and a refrigerant liquid pump P3 is provided in the refrigerant liquid circulation pipe 24. Reference numeral 25 denotes a refrigerant liquid drain pipe connected between the refrigerant liquid reservoir 1A and the rare absorption liquid reservoir 2A. An on-off valve 25V is provided in the refrigerant liquid drain pipe 25.

Reference numeral 26 denotes a cold / hot water pipe. The cold / hot water pipe 26 comprises a cold / hot water pipe 26A, an evaporator heat exchanger 26B, and a cold / hot water pipe 26C. Reference numeral 27 denotes a cooling water pipe. The cooling water pipe 27 is connected to a cooling tower (not shown) through an absorber heat exchanger 27A, a first condenser heat exchanger 27B, and a second condenser heat exchanger 27C. A circulation path for the cooling water returning to is formed. 28 is the first condenser heat exchanger 2
Cooling water pipe 27 from 7B to second condenser heat exchanger 27C
This is a cooling water pipe connected between D and the cold / hot water pipe 26, and an on-off valve 28V is provided in the middle of the cooling water pipe 28. On-off valve 28V is opened when hot water is supplied,
Water is sent from the cold / hot water pipe 26C to the cooling water pipe 27 and stored.

Reference numeral 29 denotes a low heat source supply pipe for supplying warm waste water of, for example, about 95 ° C., for example, cooling water for a generator (not shown) to the low heat source regenerator 9 as a low temperature heat source (hereinafter referred to as heat source hot water). . The low heat source supply pipe 29 includes a low heat source supply pipe 29A, a low heat source heat exchanger 29B, a low heat source return pipe 29C, a bypass pipe 29D, and a three-way valve 29E.

30 is a main controller, 31, 32, 33,
Reference numerals 34 and 35 denote temperature sensors.
Indicates the temperature T1 of the cold and hot water flowing through the cold and hot water pipe 26C, the temperature sensor 32 detects the temperature T2 of the cooling water flowing into the absorber 2, and the temperature detector 33 detects the temperature of the solution in the high temperature regenerator 4. T3 is detected, the temperature detector 34 detects the temperature T4 of the intermediate absorbent flowing out of the low heat source regenerator 9 into the intermediate absorbent pipe 15, and the temperature sensor 35 detects the return temperature T5 of the heat source hot water. Further, the main controller 30 controls the temperature of the cold / hot water T1 detected by the temperature sensor 31 to the controllers 36, 3
7, 38.

The controller 36 controls the opening of the fuel control valve 5A based on the temperature of the cold water obtained from the main controller 30, and compares the cold water temperature T1 with a set temperature of, for example, 7.0 ° C. When the cold water temperature T1 is lower than the set temperature, a close signal is output to the fuel control valve 5A, and the opening of the fuel control valve 5A gradually decreases. When the chilled water temperature T1 is higher than the set temperature, a close signal is output to the fuel control valve 5A, and the opening of the fuel control valve 5A gradually increases. Then, with the change in the opening of the fuel control valve 5A, the gas flow rate supplied to the gas burner 5 changes.

The controller 36 controls the start / stop of the intermediate absorbent pump P2 based on the temperature of the cold / hot water obtained from the main controller 30, and further controls the temperature T2 of the cooling water detected by the temperature sensor 32. The frequency of the power supplied to the intermediate absorbent pump P2 is controlled based on the temperature T3 of the solution in the high temperature regenerator 4 detected by the temperature sensor 33. Then, the power of the frequency controlled by the controller 36 is supplied from the frequency converter 40 to the intermediate absorbent pump P2,
The rotation speed of the intermediate absorbent pump P2 is controlled.

The controller 37 instructs the rated operation of the rare absorbent pump P1 based on the temperature T1 of the cold / hot water obtained from the main controller 30, and when the rated operation is not instructed, the temperature sensor 34 detects Temperature T4 of the intermediate absorbing liquid
The frequency of the electric power supplied to the rare absorbing liquid pump P1 is controlled based on. Then, the electric power of the frequency controlled by the controller 37 is supplied from the frequency converter 41 to the rare absorbing liquid pump P1.
And the number of rotations of the rare absorbing liquid pump P1 is controlled.

The controller 38 controls the opening of the flow control valve 29E. The controller 38 compares the temperature T1 of the cold / hot water obtained from the main controller 30 with the set temperature to control the flow rate. An open / close signal is output to the valve 29E and the low heat source return pipe 2
The flow rate of the heat source hot water flowing back through 9C is controlled. Here, for example, when supplying cold water, the detected cold water temperature T1
And a set temperature of, for example, 6.5 ° C.
An open / close signal is output to 9E. Further, the controller 38 changes the set temperature based on the return temperature T5 of the heat source hot water detected by the temperature sensor 35. For example, when supplying cold water, the controller 38 changes the temperature based on the cold water temperature T1 as shown by a solid line in FIG. The set temperature changes.

In the absorption chiller constructed as described above, the control at the time of supplying cold water for supplying cold water to the load via the cold / hot water pipe 26C by closing the on-off valves 19V, 21V, 25V and 28V will be described. First, the temperature T1 of the cold water detected by the temperature sensor 34 is given from the main controller 30 to each of the controllers 36, 37 and 38.

The controller 36 controls the opening of the fuel control valve 5A based on the temperature T1 of the cold water, and controls the amount of gas supplied to the gas burner 5. Further, in the heat source hot water supplied from the low heat source supply pipe 29 to the low heat source regenerator 9, the controller 38 controls the opening of the flow control valve 29E based on the temperature T1 of the cold water sent from the main controller 30, Low heat source heat exchanger 29
The flow rate of the heat source hot water flowing to the E side is controlled. For this reason, the heating amount of the high-temperature regenerator 4 increases and decreases with the increase and decrease of the heat amount of the heat source hot water, and the shortage of the heat source hot water is compensated by the high-temperature regenerator 4,
From the low heat source supply pipe 29 to the low heat source regenerator 9 of the second upper body 11
The temperature T1 of the supplied cold water can be kept at the set value regardless of the amount of heat of the hot water supplied to the heat source.

In the controller 38, as shown in FIG. 2, the set value of the cold water temperature changes according to the return temperature T5 of the heat source hot water returning to the heat source through the low heat source return pipe 29C.
When the return temperature T5 of the heat source hot water falls below, for example, 82.5 ° C., the set value of the cold water temperature gradually increases as the return temperature T5 decreases. Even when the set value of the controller 38 becomes high, since the heating amount of the high-temperature regenerator 4 is controlled according to the cold water temperature T1 as described above, the cold water temperature T1 is almost equal to the set temperature. At 7 ° C. When the temperature T1 of the chilled water is substantially constant and the set value of the chilled water temperature in the controller 38 increases, the controller 38 outputs a signal to the flow control valve 29E. Therefore, the opening of the flow control valve 29E on the low heat source heat exchanger 29B side decreases, and the three-way valve heat source supply pipe 29
The amount of heat source hot water supplied to the low heat source regenerator 9 from
The degree of opening on the side pipe 29D increases, the amount of hot water supplied from the low heat source supply pipe 29A and flowing to the side pipe 29D increases, and the return temperature T5 increases.

In the following, the low-temperature heat source regenerator 9 of the second upper body 11 is divided into a case where a sufficient amount of heat for the cold water load is obtained from the heat source hot water and a case where a sufficient amount of heat is not obtained. One control example will be described. For example, when a sufficient amount of heat for the cold water load can be obtained from the hot water flowing from the heat source, the controller 38 controls the flow control valve 29E based on the temperature T1 of the cold water sent from the main controller 30. Control the opening degree. Then, the amount of the heat source hot water flowing to the low heat source heat exchanger 29B changes according to the temperature of the cold water, whereby the temperature T1 of the cold water supplied to the load via the cold / hot water pipe 26C is maintained at the set temperature.

Therefore, when a sufficient amount of heat for the cold water load is obtained from the heat source hot water flowing through the low heat source supply pipe 29, the temperature of the cold water supplied to the load is controlled by the heating amount of the high temperature regenerator 4. Is lower than the set temperature of 7 ° C., for example. For this reason, the controller 36 does not control the fuel control valve 5A, the fuel control valve 5A remains closed, the gas burner 5 does not burn, and the high temperature regenerator 4 is stopped. Further, the controller 36 does not output a start signal to the intermediate absorbent pump P2, and the operation of the intermediate absorbent pump P2 is stopped.

The controller 37 determines whether the temperature T1 of the cold water is
Main controller 30 when lower than 7 ° C. which is the set value of 6
Is controlled based on the temperature T4 of the intermediate absorbent detected by the temperature sensor 34, instead of controlling the operation of the rare absorbent pump P1 based on the temperature signal from For example, control is performed as shown in FIG. 3 to control the rotation speed of the rare absorbing liquid pump P1.

For example, when the temperature of the intermediate absorbent is 80 ° C. or higher, the rare absorbent pump P1
When the temperature is 70 ° C. or lower, for example, the frequency is 30 Hz, which is half the rated value. When the temperature of the intermediate absorbent is between 70 and 80 ° C., the operation is performed at a frequency proportional to the temperature, for example. For this reason, when the load is small and the regeneration amount of the refrigerant is small and the regeneration temperature is low, the circulation amount of the diluted absorbing liquid is reduced, the sensible heat loss is reduced, and the COP of the absorption refrigerator is improved.

Hereinafter, circulation of the refrigerant and the solution will be described. The circulation of the refrigerant and the solution is the same as the circulation of the conventional single-use double-effect absorption refrigerator, and the operation is a chilled water supply operation.If a sufficient amount of heat is obtained from the heat source hot water to the chilled water load, the intermediate circulation is performed. The absorbing liquid pump P2 and the high-temperature regenerator 4 are stopped, and the intermediate absorbing liquid whose concentration has increased by evaporating and separating the refrigerant in the low-temperature heat source regenerator 9 is supplied to the intermediate absorbing liquid pipe 15A and the absorbing liquid pipe 1
8. Sprayed from the concentrated absorbent dispersion device 2B of the absorber 2 to the absorber heat exchanger 27A via the concentrated absorbent pipe 17A, the low-temperature heat exchanger 12, and the concentrated absorbent pipe 17B.

The refrigerant separated by the low heat source regenerator 9 is
It flows into the second condenser 10 and is cooled and condensed. And
The refrigerant liquid flows down the second refrigerant liquid pipe 23 and is
A, accumulates at 22A. The refrigerant liquid accumulated in the U seal portions 23A and 22A overflows and flows into the evaporator 1. The refrigerant liquid flowing into the evaporator 1 and stored in the refrigerant liquid reservoir 1A flows through the refrigerant liquid circulation pipe 24 by operation of the refrigerant liquid pump P3, and is sprayed from the refrigerant spray device 1B to the cold / hot water heat exchanger 26B. Then, the cold water cooled by the latent heat when the refrigerant liquid evaporates is supplied to the load from the cold / hot water heat exchanger 26B and the cold / hot water pipe 26C. Further, the refrigerant vaporized in the evaporator 1 flows to the absorber 2, and is absorbed by the concentrated absorbing liquid sprayed from the concentrated absorbing liquid spraying device 2B.

The absorption liquid that has become a diluted liquid by absorbing the refrigerant in the absorber 2 is sent to the low heat source regenerator 4 through the diluted absorption liquid pipe 14 by the diluted absorption liquid pump P1. Hereinafter, a description will be given of a control in a case where a sufficient amount of heat cannot be obtained from the heat source hot water to the cold water load during the cold water supply operation. Also in this case, the temperature T1 of the cold water detected by the temperature
6, 37 and 38 respectively.

In this case, a sufficient amount of heat with respect to the cold water load is not provided from the heat source hot water to the low heat source regenerator 9, so that the outlet temperature of the cold water cannot be lowered to the set temperature of 6.5 ° C. Therefore, the controller 36, which has obtained information from the main controller 30 that the temperature T1 of the cold water has not dropped to the predetermined set temperature, instructs the activation of the intermediate absorbent pump P2 and the ignition of the gas nana 5, and The opening degree of the fuel control valve 5A is controlled based on the temperature T1 of the cold water obtained from the main controller 30. For this reason, the flow rate of the gas supplied to the gas burner 5 is controlled according to the temperature T1 of the cold water, and the absorbing liquid is heated in the high-temperature regenerator 4 so that the refrigerant vapor is separated from the absorbing liquid.

The controller 36 determines the intermediate absorbent pump P2 based on the temperature T2 of the cooling water detected by the temperature sensor 32 and the solution temperature T3 in the high-temperature regenerator 4 detected by the temperature sensor 33.
The frequency of the power supplied to the intermediate absorbent pump P2 is controlled by the frequency converter 40 as shown in FIG.
To control the number of revolutions. That is, if the rated frequency is 6
In the case of 0 Hz, the lowest frequency is, for example, 28 Hz which is equal to or less than half of the rating, and the lower the temperature T2 of the cooling water is between the rated frequency and the lowest frequency, and the higher the temperature T3 of the solution in the high-temperature regenerator 4 is, The control is performed to increase the frequency and increase the rotation speed of the intermediate absorbent pump P2.

The controller 37 instructs the continuation of the rated operation of the rare absorbent pump P1 based on the temperature information that the temperature T1 of the chilled water obtained from the main controller 30 has not dropped to the set temperature of 7 ° C. I do. Therefore, the absorber 2, the low heat source regenerator 9, the high temperature regenerator 4, the high temperature heat exchanger 13, the low temperature regenerator 6,
A single-double-effect refrigeration cycle is formed by the low-temperature heat exchanger 12, the first condenser 7, the second condenser 10, and the evaporator 1, and it is possible to quickly cope with an increase in the load of chilled water.

In the above-described single-double-effect refrigeration cycle, the controller 38 sets the outlet temperature T1 of the cold water shown in FIG. 2 based on the return temperature T5 of the heat source hot water obtained from the temperature sensor 35. The flow control valve 29E is controlled as described above. That is, when the return temperature T5 of the heat source hot water falls below 82.5 ° C., the set value of the cold water outlet temperature T1 increases, and the controller 38 sets the flow control valve based on the detected cold water outlet temperature T1 and the set value. A signal is output to 29E to increase the opening on the side pipe 29D side and decrease the opening on the low heat source heat exchanger 29B side. Then, the opening degree of the flow control valve 29E on the side pipe 29D side increases, the heat source hot water flowing through the side pipe 29D increases, and the heat source hot water flowing on the low heat source heat exchanger 29B side decreases. For this reason, the return temperature T5 of the heat source hot water increases. When the return temperature T5 of the heat source hot water exceeds 82.5 ° C.,
The set value of the outlet temperature T1 of the chilled water becomes lower, and the controller 38 decreases the opening degree of the side pipe 29D to the flow control valve 29E based on the detected outlet temperature T1 of the chilled water and the set value, thereby reducing the heat of the low heat source. A signal for increasing the opening degree of the exchanger 29B is output.
Then, based on the signal from the controller 38, the flow control valve 2
The opening of 9E on the side pipe 29D side decreases, the heat source hot water flowing through the side pipe 29D decreases, and the heat source hot water flowing on the low heat source heat exchanger 29B side increases. Therefore, the return temperature T5 of the heat source hot water decreases.

As described above, the set value of the outlet temperature of the cold water for controlling the flow control valve 29E of the controller 38 changes based on the return temperature T5 of the heat source hot water, and the controller 38 controls the flow control valve 29E. Therefore, the temperature of the heat source hot water returning through the low heat source return pipe 29C is maintained at about 82.5 ° C. or higher. As described above, even when the amount of heat of the heat source hot water is insufficient for the load of the chilled water, the return temperature T5 of the heat source hot water does not drop significantly from a predetermined temperature, 82.5 ° C. in the embodiment. Even when the heat source hot water is returned to, for example, a generator and used for cooling, dew condensation does not occur, and the operation of the heat source hot water supply source can be stabilized.

The return temperature T5 of the heat source hot water is approximately 8
Since the temperature is stable at 2.5 ° C. or higher, the regeneration temperature of the low heat source regenerator 9 does not drop extremely, and is always maintained at the temperature required for the regeneration of the refrigerant. And COP can be improved. In the single-double-effect refrigeration cycle, the intermediate absorbent from which part of the refrigerant has been separated in the low heat source regenerator 9 is supplied to the intermediate absorbent pump P2.
To the high temperature regenerator 4. In the high temperature regenerator 4,
The intermediate absorbing liquid is heated by the gas burner 5, and the refrigerant is evaporated and separated. The intermediate absorption liquid whose concentration has increased due to separation of the refrigerant in the high temperature regenerator 4 is sent to the low temperature regenerator 6 via the high temperature heat exchanger 13. The intermediate absorbent is heated by the refrigerant vapor sent through the refrigerant vapor pipe 20 in the low-temperature regenerator 6, and the refrigerant evaporates and separates from the intermediate absorbent. Then, the concentrated absorbent having a higher concentration is sent from the low-temperature regenerator 6 to the absorber 2 via the low-temperature heat exchanger 12, and is dispersed from the concentrated absorbent dispersion device 2B.

The refrigerant vapor separated in the low heat source regenerator 9 is condensed in the second condenser 10, and the refrigerant vapor separated in the low temperature regenerator 6 is condensed in the first condenser 7. Then, the refrigerant liquid flows from the first condenser 7 and the second condenser 10 to the evaporator 1 via the first refrigerant pipe 22 and the second refrigerant pipe 23, and is sprayed from the refrigerant sprayer 1B. In the evaporator 1, when the refrigerant evaporates, the cold water cooled by the cold / hot water heat exchanger 26B by the latent heat is supplied to the cold water load. Further, the refrigerant vapor vaporized in the evaporator 1 flows to the absorber 2, and is absorbed by the concentrated absorbing liquid sprayed from the concentrated absorbing liquid spraying device 2B. The diluted absorbing liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 2 is sent to the low heat source regenerator 9 by the diluted absorbing liquid pump P1.

When supplying hot water to the load, the open / close valves 19V, 21V, 25V and 28V are opened, and the high-temperature refrigerant vapor generated in the high-temperature regenerator 4 is supplied to the refrigerant vapor pipe 20A,
The refrigerant is led to the lower body 3 via the refrigerant vapor pipe 21. The water flowing through the cold / hot water heat exchanger 26B is heated by the refrigerant vapor sent to the lower body 3 and supplied to the load. In addition, the cold and hot water heat exchanger 2
The refrigerant liquid that touches 6B and condenses and accumulates in the refrigerant liquid reservoir 1A is led to the rare absorbing liquid reservoir 2A via the refrigerant liquid drain pipe 25. Then, the rare absorbent is sent from the absorber 2 to the high-temperature regenerator 4 via the low heat source regenerator 9 by the operation of the rare absorbent pump P1 and the intermediate absorbent pump P2.

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. For example, as shown by the one-dot chain line in FIG. 2, when the return temperature of the heat source hot water becomes lower than 80 ° C., which is a lower temperature than in the above embodiment, for example, the set value of the outlet temperature of the cold water is gradually increased, and As in the example, the return temperature of the heat source hot water was set to approximately 8
It can be kept at 0 ° C. or higher. Further, since the set value of the outlet temperature of the cold water is not changed to a temperature lower than that of the above embodiment, the heat source hot water can be used more effectively to a lower temperature, and the COP of the absorption refrigerator can be further improved. .

As shown by the two-dot chain line in FIG. 2, when the return temperature of the heat source hot water is lower than 80 ° C., for example, the set value of the outlet temperature of the cold water of the controller 36 is increased to 7.5 ° C., for example. As a result, the return temperature of the heat source hot water can be maintained at about 80 ° C. or higher, as in the above embodiment. further,
Since the set value of the outlet temperature of the cold water is not changed to a temperature lower than that of the above embodiment, the heat source hot water can be used more effectively to a lower temperature, and the COP of the absorption refrigerator can be further improved, and The change of the set value of the outlet temperature of the chilled water is only required to be at 80 ° C., and the control can be simplified.

[0047]

According to the present invention, there is provided a single-double effect absorption refrigerator constructed as in the above embodiment. According to the first aspect of the present invention, a supply pipe and a return pipe for a low-temperature heat source are communicated. A three-way valve is provided to control the heating amount of the high-temperature regenerator based on the outlet temperature of the cold water taken out of the evaporator, control the three-way valve based on the outlet temperature of the cold water, and determine the return temperature of the low-temperature heat source. When the temperature falls below the temperature, the set value of the chilled water outlet temperature for the three-way valve control is increased, so that the responsiveness to the load fluctuation can be improved, regardless of the fluctuation of the low-temperature heat source supplied to the low heat source regenerator and the load fluctuation. In addition, the outlet temperature of the cold water can be maintained at the set value.

When the return temperature of the low-temperature heat source decreases, the set value of the outlet temperature of the chilled water is increased, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator is reduced, and the return temperature of the low-temperature heat source is increased to a predetermined temperature or more. Even when the cooling water of the generator is used as a low-temperature heat source, it is possible to avoid such a trouble that dew condensation occurs when the generator is cooled by the low-temperature heat source whose temperature has significantly decreased. .

Further, it is possible to prevent the regeneration temperature of the low heat source regenerator from being extremely lowered, always maintain the temperature required for the regeneration of the refrigerant, and effectively perform the regeneration of the refrigerant to improve the COP. . Moreover, such an excellent operation and effect can be obtained by operating one three-way valve, and a single-double-effect absorption refrigerator having excellent cost can be provided.

According to the second aspect of the present invention, a three-way valve is provided to connect the supply pipe and the return pipe of the low-temperature heat source, and the high-temperature regenerator is provided based on the outlet temperature of the cold water taken out from the evaporator. The three-way valve is controlled based on the outlet temperature of the chilled water, and when the return temperature of the low-temperature heat source falls below a predetermined temperature, the set value of the chilled water outlet temperature for the three-way valve control is controlled according to the drop. , The responsiveness to load fluctuations can be improved, and the outlet temperature of the chilled water can be maintained at the set value regardless of the low-temperature heat source supplied to the low heat source regenerator and the load fluctuations.

When the return temperature of the low-temperature heat source decreases, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator gradually decreases in accordance with the degree of the decrease, and the amount of heat radiation in the low-temperature heat source regenerator gradually decreases. The return temperature of the low-temperature heat source can be maintained at a predetermined temperature or higher irrespective of changes in load,
Even when the cooling water or the like of the generator is used as the low-temperature heat source, it is possible to avoid a trouble such as dew condensation when the generator is cooled by the low-temperature heat source whose temperature is greatly reduced.

Further, the regeneration temperature of the low heat source regenerator can be prevented from being extremely lowered, and even when the amount of heat of the low temperature heat source changes, the heat of the low temperature heat source is effectively used, and the regeneration of the refrigerant is effectively performed. To improve the COP. Furthermore, according to the invention described in claim 3, a three-way valve is provided so as to communicate the supply pipe and the return pipe of the low-temperature heat source, and the heating amount of the high-temperature regenerator is determined based on the outlet temperature of the cold water taken out from the evaporator. When the return temperature of the low-temperature heat source falls below a predetermined temperature, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator is reduced. Therefore, the responsiveness to the load variation can be improved, and the outlet temperature of the cold water can be maintained at the set value regardless of the amount of the low-temperature heat source supplied to the low heat source regenerator and the load variation.

When the return temperature of the low-temperature heat source decreases, the amount of the low-temperature heat source flowing into the low-temperature heat source regenerator is reduced, the amount of heat radiation in the low-temperature heat source regenerator is reduced, and the return temperature of the low-temperature heat source is reduced to a predetermined value. The temperature can be maintained above the temperature, and even if the cooling water of the generator is used as a low-temperature heat source, avoid troubles such as condensation when cooling the generator with the low-temperature heat source whose temperature has dropped significantly. Can be.

Further, it is possible to prevent the regeneration temperature of the low heat source regenerator from being extremely lowered, to always maintain the temperature necessary for the regeneration of the refrigerant, and to effectively perform the regeneration of the refrigerant to improve the COP. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a single-double effect absorption refrigerator.

FIG. 2 is an explanatory diagram showing a relationship between a return temperature of a heat source hot water and a set value of a cold water outlet temperature.

FIG. 3 is an explanatory diagram showing a control example of a rare absorbing liquid pump.

FIG. 4 is an explanatory diagram showing a control example of an intermediate absorbent pump.

FIG. 5 is a schematic configuration diagram of a conventional single double effect absorption refrigerator.

[Explanation of symbols]

 Reference Signs List 1 evaporator 2 absorber 3 lower body (evaporator absorber body) 4 high temperature regenerator 6 low temperature regenerator 7 first condenser 8 low heat source regenerator condenser body 9 low heat source regenerator 10 second condenser 11 low temperature regeneration Condenser condenser 12 low-temperature heat exchanger 13 high-temperature heat exchanger 26 cold / hot water pipe 29D bypass pipe 29E flow control valve (three-way valve) 30 main controller 38 controller

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-257668 (JP, A) JP-A-59-189259 (JP, A) JP-A-3-137461 (JP, A) JP-A-56-189 37467 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 15/00 F25B 15/00 306

Claims (3)

(57) [Claims] An evaporator absorber body containing an evaporator and an absorber, a low temperature regenerator condenser body containing a low temperature regenerator and a condenser, a low heat source regenerator using warm waste water as a low temperature heat source. A low heat source regenerator condenser body containing a condenser and a high temperature regenerator are connected by piping to form a circulation path for the absorbing liquid and the refrigerant, and a three-way valve is provided so as to communicate the supply pipe and the return pipe of the low temperature heat source. The heating amount of the high-temperature regenerator is controlled based on the outlet temperature of the cold water taken out of the evaporator, the three-way valve is controlled based on the outlet temperature of the cold water, and the return temperature of the low-temperature heat source becomes equal to or lower than a predetermined temperature. A single-double-effect absorption refrigerator having a controller for increasing the set value of the chilled water outlet temperature for controlling the three-way valve when the refrigerator is operated. 2. An evaporator absorber body containing an evaporator and an absorber, a low temperature regenerator condenser body containing a low temperature regenerator and a condenser, and a low heat source regenerator using hot waste water as a low temperature heat source. A low heat source regenerator condenser body containing a condenser and a high temperature regenerator are connected by piping to form a circulation path for the absorbing liquid and the refrigerant, and a three-way valve is provided so as to communicate the supply pipe and the return pipe of the low temperature heat source. Provided, while controlling the heating amount of the high-temperature regenerator based on the outlet temperature of the cold water taken out from the evaporator, controlling the three-way valve based on the outlet temperature of the cold water, and the return temperature of the low-temperature heat source falls below a predetermined temperature. A single double effect absorption refrigerator comprising a controller for gradually increasing the set value of the chilled water outlet temperature for controlling the three-way valve according to the above. 3. An evaporator absorber body containing an evaporator and an absorber, a low temperature regenerator condenser body containing a low temperature regenerator and a condenser, and a low heat source regenerator using hot waste water as a low temperature heat source. A low heat source regenerator condenser body containing a condenser and a high temperature regenerator are connected by piping to form a circulation path for the absorbing liquid and the refrigerant, and a three-way valve is provided so as to communicate the supply pipe and the return pipe of the low temperature heat source. Provided, while controlling the heating amount of the high-temperature regenerator based on the outlet temperature of the cold water taken out of the evaporator, controlling the three-way valve based on the outlet temperature of the cold water, and the return temperature of the low-temperature heat source dropped below a predetermined temperature. Sometimes, a single-double-effect absorption refrigerator equipped with a controller for reducing the amount of low-temperature heat source flowing into the low-temperature heat source regenerator in accordance with the decrease.