JP2806491B2 - Absorption refrigerator and its operation control method - 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 driven by two heat sources, ie, low-temperature exhaust heat such as cogeneration and fuel heat, and a method of controlling the operation thereof.

[0002]

2. Description of the Related Art As shown in FIG. 6, for example, low-temperature exhaust heat from cogeneration or the like, that is, heated hot water or heated steam (hereinafter referred to as hot water) W, and high-quality fuel, that is, city gas G
In the two-heat-source driven absorption refrigerator, the two low-temperature regenerators (the first regenerator 1) are used in order to secure the performance at the time of the two-heat source drive.
3A and the second regenerator 13B) and the condenser (the first condenser 1)
4A and the second condenser 14B). In the figure, reference numeral 11 denotes an absorber, 12 denotes a high-temperature regenerator, 15 denotes an evaporator, and 16 denotes a low-temperature solution heat exchanger.

[0003]

Therefore, there is a problem that the structure is enlarged and the control is complicated.

[0004] It is an object of the present invention to provide an absorption chiller whose structure is reduced in size and weight and simplified, and whose control is simplified, and an operation control method thereof.

[0005]

The absorption refrigerator according to the present invention comprises:
A second three-way valve that is provided in a low-temperature exhaust line for cogeneration or the like and switches low-temperature exhaust heat to a second bypass line or a waste heat-solution heat exchanger, which will be described later, and a low-temperature exhaust heat that has passed through the second three-way valve. (1) a first three-way valve for switching to a bypass line side or a low-temperature regenerator side, an absorber, an evaporator, and a condenser;
A low-temperature solution heat exchanger, a third three-way valve, a waste heat-solution heat exchanger, a high-temperature solution heat exchanger and a high-temperature regenerator provided in a line connecting the absorber and the low-temperature regenerator; A flow control valve provided in the supply line, a first temperature sensor provided in the low-temperature exhaust heat line, a second temperature sensor provided in the cooling line from the evaporator, a first temperature sensor, a first temperature sensor, And a control unit to which a third three-way valve and an on-off valve are respectively connected.

The operation control method according to the present invention determines whether or not the temperature of low-temperature exhaust heat from cogeneration or the like is equal to or higher than a temperature set value. Adjust the gas flow rate according to the load, if it is above the temperature set value, determine whether the cooling load is below the load set value, if the chilled water outlet temperature is below the set value, select the hot water firing mode, Adjust the flow rate of low-temperature exhaust heat to the low-temperature regenerator according to the cooling load.If the chilled water outlet temperature is equal to or higher than the set value, select the exhaust heat input plus gas firing mode and exhaust the low-temperature exhaust heat according to the cooling load. Adjusting the flow rate to the solution heat exchanger;

[0007]

According to the present invention, the hot water from cogeneration or the like is regenerated according to the amount and temperature of the hot water to the waste heat / solution heat exchanger side when the two heat sources are simultaneously driven, and to the low temperature when driven only by the hot water. Switch to the container side and run.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a cogeneration system 1
Hot water pump L, the second three-way valve V
2, a first three-way valve V1, a three-way valve 3, and a cooling tower 4 are interposed.

On the other hand, an absorption refrigerator generally designated by the reference numeral 10 is provided with an absorber 11, a high-temperature regenerator 12, a low-temperature regenerator 13, a condenser 14 and an evaporator 15 in a known manner. To L5. In the line L2, a solution pump P, a low-temperature solution heat exchanger 16, a third three-way valve V3, a waste heat-solution heat exchanger 17, and a high-temperature solution heat exchanger 18 are interposed in order from the absorber 11 side. I have. Reference numeral 19 denotes a refrigerant pump.

The first three-way valve V1 selectively connects the second three-way valve V2 side to the first bypass line B1 side or the low temperature regenerator line L6 side passing through the low temperature regenerator 13, and the second three-way valve V2 Selectively connects the cogeneration 1 side to the second bypass line side or the solution line L7 side passing through the waste heat-solution heat exchanger 17, and the third three-way valve V3 connects the absorber 11 side to the high temperature regenerator. It is selectively connected to the 12 side or the low temperature regenerator 13 side.

On the other hand, a hot water line L1 is provided with a first temperature sensor S1 for detecting a temperature TH.
A second temperature sensor S2 for detecting a chilled water outlet temperature TL is provided on the cooling line L8 from the cooling load CL to the cooling load CL. The gas supply line L9 to the high-temperature regenerator 12 is provided with a flow control valve V4. And the first to first
The third three-way valves V1 to V3, the flow control valve V4, the first and second temperature sensors S1, S2, and the solution pump P are connected to the control unit 20, respectively. In addition, each line L1
L9 flows as indicated by the arrow.

Next, the mode of operation control will be described.

Referring to FIG. 2, the control unit 20 comprises:
Based on the signals from the second sensors S1 and S2, the temperature TH of the hot water line L1 and the temperature TL of the cooling line L8 are detected (step S1), and whether the temperature TH is equal to or higher than the hot water line temperature set value, that is, It is determined whether or not there is (step S2). In the following cases, that is, in the case of NO, the gas firing mode described later is selected (step S3), and in the above case, that is, in the case of YES, whether the temperature TL is lower than the cooling line temperature set value, that is, the cooling load is It is determined whether the mode is sufficient (step S4). Y
If it is ES, select the hot water burning mode (step S
5) In the case of NO, the exhaust heat input plus gas firing mode is selected (step S6).

In the gas firing mode, that is, when there is no warm exhaust heat, the first and second three-way valves V1 and V2 are connected to the bypass line B
1, the B3 side is fully opened, the third three-way valve V3 is fully opened by switching to the high temperature regenerator 12 side, the opening degree of the flow control valve V4 is adjusted, and the flow rate of the solution pump P is set to gas-fired circulation. Set to quantity. That is, as shown in FIG. 3, the control unit 20 detects the temperature TL (step S10),
It is determined whether or not the temperature TL is equal to or lower than the cooling line temperature set value (step S11). If YES, the opening of the flow control valve V4 is controlled in a direction to decrease the flow rate of the gas G according to the load (step S12). ). In the case of NO, the opening of the flow control valve V4 is controlled in a direction to increase the flow rate of the gas G according to the load.

In the hot water firing mode, the first three-way valve V1 is switched to the low temperature regenerator line L6 to adjust the opening, and the second three-way valve V2 is switched to the second bypass line to be fully opened.
The three-way valve V3 is switched to the low-temperature regenerator 13 side to be fully opened to eliminate an extra pressure loss, the flow control valve V4 is fully closed, and the flow rate of the solution pump P is set to the set circulation amount for hot water heating. That is, as shown in FIG.
L is detected (step S20), and it is determined whether the temperature TL is equal to or lower than the cooling line temperature set value (step S2).
1). If YES, the opening of the first three-way valve V1 is controlled in a direction to decrease the amount of hot water according to the load (step S2).
2) In the case of NO, the opening of the first three-way valve V1 is controlled in a direction to increase the amount of hot water according to the load (step S2).
3).

In the exhaust heat input plus gas firing mode, that is, when the two heat sources are driven, the first three-way valve V1 is switched to the first bypass line side, the second three-way valve V2 is switched to the solution line L7 to be fully opened, and the third three-way valve is opened. V3 is switched to the exhaust heat / solution heat exchanger 17 side and fully opened, and the flow control valve V4 is opened to adjust the opening degree, and the flow rate of the solution pump P is set to the set circulation amount for gas firing. That is, as shown in FIG. 5, the control unit 20 detects the temperature TL (step S30), and
It is determined whether L is equal to or less than the cooling line temperature set value (step S31). If the determination is YES, the opening of the flow control valve V4 is controlled in a direction to decrease the gas amount according to the load (step S32). In the case of NO, the flow control valve V4 is controlled to increase the gas amount according to the load. Is controlled (step S33).

[0018]

As described above, according to the present invention, two low-temperature regenerators and one condenser are conventionally required, and the structure is reduced in size and weight, and the control is simplified. It can be simplified.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention.

FIG. 2 is a schematic control flowchart.

FIG. 3 is a control flowchart of a gas firing mode.

FIG. 4 is a control flowchart of a hot water firing mode.

FIG. 5 is a control flowchart of an exhaust heat input plus gas firing mode.

FIG. 6 is an overall configuration diagram showing an example of a conventional absorption refrigerator.

[Explanation of symbols]

 CL: Cooling load G: City gas L1: Hot water line L2-L5: Line L6: Low temperature regenerator line L7: Solution line L8: Cooling line L9: Gas Supply line P: Solution pump S1: First temperature sensor S2: Second temperature sensor V1: First three-way valve V2: Second three-way valve V3: Third three-way valve V4 ..Flow control valve B1 ... First bypass line B2 ... Second bypass line 1 ... Cogeneration device 2 ... Hot water pump 3 ... Three-way valve 4 ... Cooling tower 10 ... Absorption refrigerator 11 Absorber 12 High temperature regenerator 13 Low temperature regenerator 13A First low temperature regenerator 13B Second low temperature regenerator 14 Condenser 14A・ First condenser 14B ・ ・ ・ Second condenser 15 ・ ・ ・ Evaporation 16 ... low-temperature solution heat exchanger 17 ... heat - solution heat exchanger 18 ... high temperature solution heat exchanger 19 ... refrigerant pump 20 ... control unit

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 15/00 306 F25B 15/00 303

Claims (2)

(57) [Claims] A second three-way valve provided in a low-temperature exhaust line such as a cogeneration system for switching low-temperature exhaust heat to a second bypass line or a waste heat-solution heat exchanger;
A first three-way valve for switching the low-temperature exhaust heat passed through the three-way valve to the first bypass line side or the low-temperature regenerator side, an absorber, an evaporator, and a condenser, and a line connecting the absorber and the low-temperature regenerator. A low-temperature solution heat exchanger, a third three-way valve, a waste heat-solution heat exchanger, a high-temperature solution heat exchanger, and a high-temperature regenerator; a flow control valve provided in a fuel supply line of the high-temperature regenerator; A first temperature sensor provided in the heat line and a second temperature sensor provided in the cooling line from the evaporator;
An absorption refrigerator comprising: a control unit to which a second temperature sensor, first to third three-way valves, and an on-off valve are respectively connected. 2. It is determined whether or not the temperature of low-temperature exhaust heat from cogeneration or the like is equal to or higher than a temperature set value. If the temperature is equal to or lower than the temperature set value, a gas firing mode is selected and a gas flow rate is selected according to a cooling load. If the cooling load is lower than the set value, determine whether the cooling load is lower than the set value.If the cooling water outlet temperature is lower than the set value, select the hot water heating mode. Adjust the flow rate of the exhaust heat to the low-temperature regenerator.If the chilled water outlet temperature is higher than the set value, select the exhaust heat input plus gas firing mode, and according to the cooling load, send the low-temperature exhaust heat to the heat-solution heat exchanger. A method for controlling the operation of an absorption refrigerator, comprising adjusting the flow rate of water.