JP2000257979A - Method for operating absorption heater chiller utilizing exhaust heat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a high-temperature exhaust gas or cooling water from flowing in by preventing an absorption liquid from being crystallized by the high-temperature regenerator of an absorption heater chiller during an interruption. SOLUTION: An air-conditioning load is divided into a first level, a second level that is larger than the first level, and a third level that is larger than the second level. When the air-conditioning load is at the first level, heating by the gas burner is made by adjusting thermal power based on the air- conditioning load, heating by an exhaust gas from a gas turbine is made by adjusting the amount of heat based on the air-conditioning load, when the air- conditioning load is at the second level, and heating by the exhaust gas of the gas turbine that is operated at a rating and that by gas burner for adjusting thermal power, based on the air-conditioning load are used together when the air-conditioning load is at the third level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses heat generated by high-temperature exhaust gas and cooling water from a power generation gas turbine or the like, that is, so-called exhaust heat, to improve thermal efficiency and reduce fuel consumption. It relates to an operation method of an absorption chiller / heater.

[0002]

2. Description of the Related Art In a conventional exhaust heat-utilizing absorption chiller / heater, the amount of high-temperature exhaust gas and cooling water from a gas turbine operating at rated operation is adjusted to reduce the amount of absorption liquid heated by a high-temperature regenerator. The amount of refrigerant vapor to be evaporated and separated is controlled, thereby controlling the capacity of the apparatus. For this reason, a valve for controlling the amount of waste heat taken in is required to have high accuracy and is expensive.

When high-temperature exhaust gas or cooling water flows from a flow control valve into a high-temperature regenerator of a suspended absorption chiller / heater,
Since there is a danger that the absorbing solution is concentrated and crystallized, it is necessary to pay strict attention to make sure that the absorbing solution does not flow, and the provision of an on-off valve as a countermeasure has also been a factor that increases the price of the apparatus.

[0004]

SUMMARY OF THE INVENTION In an absorption chiller / heater utilizing waste heat, there is no danger of high temperature exhaust gas or cooling water flowing into a high-temperature regenerator of a suspended absorption chiller / heater and the absorption liquid being crystallized. It is necessary to keep the equipment price from rising, and this has been a problem to be solved.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention heats an absorbing liquid by heat of combustion by a burner and waste heat supplied from another heat source device to evaporate and separate a refrigerant. In the exhaust heat utilizing absorption chiller / heater provided with a regenerator, the operation of the heat source device is controlled based on the level of the air conditioning load to control the heat amount of the exhaust heat, and the heating by the combustion heat and the exhaust heat A first operation method for switching / using heating by heating, and

In the first operating method, the air conditioning load is divided into a first level, a second level larger than the first level, and a third level larger than the second level,
When the air conditioning load is at the first level, the heating by the combustion heat controlled based on the air conditioning load is performed, and when the air conditioning load is at the second level, the output of the other heat source device is controlled based on the air conditioning load. From the other heat source device that performs rated operation when the air conditioning load is at the third level.
A second operating method configured to perform heating by the combustion heat controlled based on an air conditioning load;

In the second operation method, when the air conditioning load shifts from the first level to the second level and shifts from heating by the combustion heat to heating by the exhaust heat, the air conditioning load is supplied to the burner. And a third operation method in which the amount of fuel to be consumed is gradually reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 illustrates a double-effect absorption chiller / heater that circulates cold or hot water to a load, and uses water as a refrigerant and lithium bromide (LiB) as an absorption liquid.
r) An aqueous solution is used.

In the figure, reference numeral 1 denotes the thermal power of the gas burner 2;
For example, a high-temperature regenerator, which is configured to evaporate and separate a refrigerant by heating an absorbing liquid with exhaust gas discharged from a gas turbine 3 for power generation, 4 is a low-temperature regenerator, 5 is a condenser, and 6 is a low-temperature regenerator 4 A high temperature body in which the condenser 5 is housed, 7 an evaporator, 8
Is an absorber, 9 is a low temperature body in which the evaporator 7 and the absorber 8 are housed, 10 is a low temperature heat exchanger, 11 is a high temperature heat exchanger, 12
15 is an absorption liquid pipe, 16 is an absorption liquid pump, 17 to 21 is a refrigerant pipe, 22 is a refrigerant pump, 23 is a cold / hot water pipe through which cold or hot water circulates and supplied to an air conditioning load (not shown), 24
Is a cooling water pipe, 25 to 27 are on-off valves, and these devices are respectively connected by piping as shown in FIG. 2, and the configuration itself is conventionally known.

The gas burner 2 provided in the high-temperature regenerator 1 is a burner whose thermal power can be adjusted, and the thermal power can cover 0-50% of the air conditioning load. On the other hand, the gas turbine 3 can cover up to 25 to 50% of the amount of heat of the discharged combustion gas with respect to the air conditioning load.

In the double effect absorption chiller / heater of the above construction, the on-off valves 25, 26 and 27 are closed, cooling water is supplied to the cooling water pipe 24, and the gas burner 2 is ignited, and the gas turbine 3 is started up. Is supplied and the rare absorbing liquid is heated by the high-temperature regenerator 1, a refrigerant vapor evaporated and separated from the rare absorbing liquid and an intermediate absorbing liquid in which the refrigerant vapor is separated and the concentration of the absorbing liquid is increased are obtained.

The high-temperature refrigerant vapor generated by the high-temperature regenerator 1 enters the low-temperature regenerator 4 through the refrigerant pipe 17, and is generated by the high-temperature regenerator 1 and passes through the high-temperature heat exchanger 11 by the absorbing liquid pipe 13. Then, the intermediate absorbing liquid that has entered the low-temperature regenerator 4 is heated and condensed, and enters the condenser 5.

The refrigerant heated by the low-temperature regenerator 4 and evaporated and separated from the intermediate absorption liquid enters the condenser 5 and enters the cooling water pipe 2.
The refrigerant exchanges heat with water flowing in the pipe 4 to be condensed and liquefied, and enters the evaporator 7 through the refrigerant pipe 18 together with the refrigerant condensed and supplied from the refrigerant pipe 17.

The refrigerant liquid entering the evaporator 7 and stored in the refrigerant liquid reservoir is sprayed by the refrigerant pump 22 onto the heat transfer pipe 23A connected to the cold / hot water pipe 23, and is supplied with water supplied through the cold / hot water pipe 23. The heat exchange evaporates and cools the water flowing inside the heat transfer tube 23A.

The refrigerant evaporated by the evaporator 7 enters the absorber 8 and is heated by the low-temperature regenerator 4 to evaporate and separate the refrigerant. Supplied via the low temperature heat exchanger 10,
Absorbed by the concentrated absorbent sprayed from above.

The absorption liquid whose concentration has been reduced by absorbing the refrigerant in the absorber 8, that is, the diluted absorption liquid, is preheated in the low-temperature heat exchanger 10 and the high-temperature heat exchanger 11 by the operation of the absorption liquid pump 16 to regenerate the high-temperature. It is sent from the absorbing liquid tube 12 to the vessel 1.

When the absorption chiller / heater is operated as described above, the chilled water cooled by the heat of vaporization of the refrigerant in the heat transfer tube 23A provided inside the evaporator 7 is converted into the chilled / hot water pipe 2.
3 can be circulated to an air-conditioning load (not shown)
Cooling operation can be performed.

On the other hand, when the on-off valves 25, 26 and 27 are opened and the gas burner 2 is ignited without cooling water flowing through the cooling water pipe 24, or when the rare absorbent is heated by the high temperature regenerator 1 by the exhaust gas of the gas turbine 3, The refrigerant vapor evaporated from the rare absorbing liquid in the high-temperature regenerator 1 is mainly supplied to the refrigerant pipes 17 and 2 having a small flow path resistance
1 and enters the absorber 8 and the evaporator 7 of the low-temperature body 9 and exchanges heat with the water supplied from the cold / hot water pipe 23 via the heat transfer pipe 23A to condense. 2
The water flowing inside 3A is heated.

The refrigerant condensed by performing the heating action in the evaporator 7 enters the absorber 8 through the refrigerant pipe 20 and is supplied to the high-temperature regenerator 1.
The refrigerant is vaporized and separated by the above, mixed with the absorbing liquid flowing from the absorbing liquid pipe 15, and is preheated by the low-temperature heat exchanger 10 and the high-temperature heat exchanger 11 by the operation of the absorbing liquid pump 16 to be heated by the high-temperature
Sent to

Then, the hot water heated by the heat transfer pipe 23A inside the evaporator 7 is circulated and supplied to an air-conditioning load (not shown) through the cold / hot water pipe 23 to perform a heating operation and the like.

Reference numeral 30 denotes a controller provided in the double-effect absorption chiller / heater having the above-mentioned operation function, which is provided with a microcomputer, a storage means, etc., and circulates and supplies chilled / hot water to an air conditioning load (not shown). The temperature information of the cold / hot water flowing out of the heat transfer tube 23A of the evaporator 7 to the cold / hot water tube 23 is supplied to a temperature sensor 31, 3,
2, the thermal power of the gas burner 2 and the output of the gas turbine 3 are controlled based on the temperature information of the cold / hot water, and the amount of refrigerant vapor generated by evaporating and separating from the absorbent in the high temperature regenerator 1 is controlled. I have.

That is, the controller 30 comprises a temperature sensor 31,
The magnitude of the air-conditioning load (not shown) is obtained from the temperature difference between the cold and hot water detected by 32 and whether the load is at a first level (less than 25% of the total load) set in advance as shown in FIG. Determine if it is at a second level greater than the first level (25% or more and less than 50% of full load) or at a third level greater than the second level (50% or more of full load) When the load is at the first level, heating by the gas burner 2 is selected, and when the air conditioning load is at the second level, heating by exhaust gas from the gas turbine 3 is selected, and the air conditioning load is at the third level. In some cases, a combination of heating by the gas burner 2 and heating by exhaust gas from the gas turbine 3 is selected.

When the controller 30 selects heating by the gas burner 2, the temperature of the cold / hot water detected by the temperature sensor 32, that is, the heat is operated by the evaporator 7, flows out to the cold / hot water pipe 23, and is circulated and supplied to the air conditioning load. The amount of heat supplied to the high-temperature regenerator 1 is controlled by adjusting the opening of the fuel control valve 2A of the fuel supply pipe connected to the gas burner 2 so that the temperature of the cold and hot water is maintained at a predetermined set temperature. This controls the amount of refrigerant vapor that evaporates and separates in the high-temperature regenerator 1.

When the controller 30 selects heating by the exhaust gas discharged from the gas turbine 3, the controller 30
The output of the gas turbine 3 is controlled so that the temperature of the cold / hot water detected by the gas turbine 2 is maintained at a predetermined set temperature, so that the heat quantity of the exhaust gas supplied to the high-temperature regenerator 1 is controlled. Thus, the amount of refrigerant vapor that evaporates and separates in the high-temperature regenerator 1 is controlled.

Further, when the controller 30 selects both the heating by the gas burner 2 and the heating by the exhaust gas discharged from the gas turbine 3, the controller 30 operates the gas turbine 3 at a rated value, and controls the temperature of the cold / hot water detected by the temperature sensor 32. By adjusting the opening of the fuel adjustment valve 2A of the fuel supply pipe connected to the gas burner 2 so that the temperature is maintained at a predetermined set temperature,
The amount of heat supplied to the high-temperature regenerator 1 is controlled, whereby the amount of refrigerant vapor that evaporates and separates in the high-temperature regenerator 1 is controlled.

When the air conditioning load is increased from the first level to the second level and switching from heating by the gas burner 2 to heating by the exhaust gas of the gas turbine 3 is performed,
The temperature of the exhaust gas supplied from the gas turbine 3 to the high temperature regenerator 1 is detected by a temperature sensor 33, and the fuel regulating valve 2A is gradually throttled based on the temperature information detected by the temperature sensor. It takes time to start up the gas turbine 3 when switching to heating by the exhaust gas of the gas turbine 3, so that even if the supply of the high-temperature exhaust gas is delayed, the heat supplied to the high-temperature regenerator 1 is not interrupted.

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

For example, a gas burner 2 having a thermal power capable of completely covering the air-conditioning load may be used so that there is no demand for electric power, so that the air-conditioning load can be completely satisfied even when the gas turbine 3 is not operated. .

The exhaust heat supplied to the high-temperature regenerator 1 may be supplied from cooling water that has cooled the gas turbine 3 and the like.

As the fluid to be cooled or heated by the evaporator 7 and supplied to the air-conditioning load after being supplied to the air-conditioning load without changing the phase as in the above embodiment, air-conditioning using latent heat is possible. As described above, it is also possible to supply fluorocarbon or the like with a phase change.

[0031]

As described above, according to the present invention, the operation of the heat source device is controlled based on the level of the air-conditioning load and supplied from the heat source device even in the exhaust heat utilizing absorption chiller / heater manufactured at low cost. Since the heat quantity of the exhaust heat is controlled, high-temperature exhaust heat is not supplied to the high-temperature regenerator of the absorption chiller / heater that is not in operation, and therefore, there is no inconvenience such as crystallization of the absorption liquid.

In particular, according to the third aspect of the present invention, when switching from heating by the burner to heating by exhaust heat of the gas turbine or the like, it takes time to start the gas turbine or the like, and supply of high-temperature exhaust heat may be delayed. However, since the heat supplied to the high-temperature regenerator is not interrupted, stable air conditioning can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an absorption chiller / heater.

FIG. 2 is an explanatory diagram of a control method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Gas burner 2A Fuel control valve 3 Gas turbine 4 Low temperature regenerator 5 Condenser 6 High temperature body 7 Evaporator 8 Absorber 9 High temperature body 10 Low temperature heat exchanger 11 High temperature heat exchanger 12-15 Absorption liquid pipe 16 Absorption Liquid pump 17-21 Refrigerant pipe 22 Refrigerant pump 23 Cold / hot water pipe 24 Cooling water pipe 25/26/27 Open / close valve 30 Controller 31/32/33 Temperature sensor

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Claims (3)

[Claims] 1. An exhaust heat utilizing absorption chiller / heater provided with a regenerator for heating an absorbent and evaporating and separating a refrigerant by using heat of combustion by a burner and exhaust heat supplied from another heat source device. Controlling the operation of the heat source device based on the level of the heat source to control the amount of heat of the exhaust heat, and switching / using heating by the combustion heat and heating by the exhaust heat. How to operate the water heater. 2. The air conditioning load is divided into a first level, a second level larger than the first level, and a third level larger than the second level, and the air conditioning load is at the first level. Sometimes, the heating by the combustion heat controlled based on the air conditioning load is performed, and when the air conditioning load is at the second level, the heating by the exhaust heat supplied from the other heat source device whose output is controlled based on the air conditioning load is performed. The air conditioning load is 3rd
2. The exhaust heat according to claim 1, wherein heating is performed by using the exhaust heat supplied from the other heat source device which is operated at a rated operation and the combustion heat which is controlled based on an air conditioning load. How to use absorption chiller / heater. 3. When the air conditioning load shifts from the first level to the second level, and when shifting from heating by the combustion heat to heating by the exhaust heat, the fuel supplied to the burner is gradually reduced. 3. The method for operating a waste heat utilizing absorption chiller / heater according to claim 2, wherein: