JPS5844302B2 - Hybrid absorption heat pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hybrid absorption heat pump capable of simultaneously producing high temperature water and cold water.

Conventionally, in an absorption refrigeration cycle, if you wanted to obtain hot water at the same time as cooling, you would use a condenser or a separate dedicated hot water heat exchanger to generate hot water using the heat of steam generated in a generator, for example. When hot water or steam is used as a heat source for heating a solution in a generator, the temperature of the hot water obtained is lower than the temperature of the heat source hot water or steam, which is particularly important in power plants, which have recently become a problem in terms of energy conservation and pollution prevention. When using relatively low-temperature heat source hot water such as heated wastewater in a conventional absorption heat pump, the temperature of the hot water obtained is so low that it has no value.

To solve this problem, we installed a heat pump cycle that includes an absorber and an evaporator on the high-pressure side of an intermediate-pressure generator and a condenser, and a refrigeration cycle that includes an absorber and evaporator on the low-pressure side. A hybrid absorption heat pump has been considered, which can simultaneously generate water at a higher temperature than the heat source hot water and cold water at a lower temperature than the cooling water, and has an extremely simple structure with an integrated structure. This is related to its improvement.

That is, to explain an example before the improvement of the present invention as shown in FIG. ) is maintained.

AH is a high-pressure stage absorber, EH is a high-pressure stage evaporator, and the pressure is higher than the intermediate pressure. AL is a low-pressure stage absorber, and EL is a low-pressure stage evaporator, which is lower than the intermediate pressure.

Regarding the solution side cycle, the low pressure stage absorber AL is connected to the high pressure stage absorber AH via the solution pump 1 and intermediate concentration solution pipe 2, and the high pressure stage absorber AH is connected to the generator G via the dilute solution pipe 3 and valve 4. The generator G is connected to the low pressure absorber AL via a concentrated solution pipe 5 and a valve 6.

Regarding the refrigerant side cycle, the low-pressure evaporator EL is connected to the high-pressure evaporator EH via a refrigerant pump T1, a refrigerant pipe 8, and valves 9 and 10.

Further, a branch pipe 12 having a valve 11 is connected to the refrigerant pipe 8 in order to circulate the refrigerant liquid in the low-pressure stage evaporator EL.

The condenser C and the low pressure stage evaporator EL have a pressure reducing valve 29 and a return pipe 3.
Connected by 0.

High pressure stage absorber A connects the solution side and refrigerant side.
Steam pipe 13 connecting H and high pressure stage evaporator EH, steam pipe 14 connecting generator G and condenser C, and low pressure stage absorber A
A steam pipe 15 is provided to connect L and the low pressure stage evaporator EL.

Hot water pipe 1 as a heat source in relation to receiving and receiving heat from the outside
6.17 are respectively installed in the generator G and the high pressure stage evaporator EH, and the inlet pipe 21 having a valve 19 and branching to a three-way valve 20 is connected to the hot water pipe 160 inlet part 18, and the outlet part 22 is connected to a three-way valve 20, and the three-way valve 20 is connected to another three-way valve 23 through a communication pipe 24.

One port of the three-way valve 23 is connected to the inlet portion 26 of the hot water pipe 1T, and the other port is connected to an outlet pipe 28 connected to the outlet portion 27 and further connected to the heat exchanger X8.

The condenser C and the low-pressure stage absorber AL are equipped with cooling water pipes 31, 32 through which cooling water flows.

The outlet of the cooling water pipe 31 is connected to the heat exchanger Xw.

The high pressure stage absorber AH is equipped with a high temperature water pipe 33 for obtaining the required high temperature water, and the low pressure stage evaporator EL is equipped with a cold water pipe 34 for obtaining the required cold water.

As for the control related to high temperature water, a temperature detector 35 is provided at the outlet of the high temperature water pipe 33 and controls the valve 20 via the three-way valve 23 and the signal switch 25.

A temperature detector 36 is provided at the outlet of the cold water pipe 34 and controls the three-way valve 20 via a signal switch 25.

37 and 38 are liquid level detectors for valve 10 or valve 6, respectively.
control.

Heat exchanger X8. The refrigerant is heated by Xw, and the efficiency is increased by effectively utilizing the heat.

To explain the operation and effect of this conventional example, in a heat source hot water system, waste water from a power plant, for example, is supplied from the outside to the inlet pipe 21, the valve 19 is opened, and the three-way valve 20 is closed on the inlet pipe 21 side and the outlet part is 22 and the communication pipe 24 are placed in communication with each other, and the valve 25
is closed, the three-way valve 23 is placed in a state where the communication pipe 24 and the inlet part 26 are in communication, and the heat source hot water is connected to the hot water pipe 16 and the communication pipe 24.
, and is discharged to the outside from the outlet pipe 28 via the hot water pipe 17.

Of course, it is also possible to supply hot water to the hot water pipes 16, 17 not in series but in parallel, or separately from separate hot water sources.

The refrigerant liquid in the low pressure stage evaporator EL enters the high pressure stage evaporator EH via the refrigerant pipe 8 and the valve 9.10 by the refrigerant pump 7 and into the hot water pipe 1.
It is heated by the hot water of T and evaporates, and enters the high pressure stage absorber AH through the steam pipe 13.

On the other hand, the intermediate concentration solution is transferred from the low pressure stage absorber AL to the solution pump 1.
, passes through the intermediate concentration solution tube 2, passes through the low-pressure stage and high-pressure stage heat exchangers XL and XH, is heated, enters the high-pressure stage absorber AH, and absorbs the above-mentioned refrigerant vapor.

At this time, the solution is heated by the absorbed heat to a temperature corresponding to an increase in the boiling point, heating the high temperature water pipe 33, and high temperature water having a higher temperature than the heat source hot water can be obtained.

The dilute solution that has absorbed the refrigerant enters the generator G through the dilute solution pipe 3 and the valve, is heated by hot water in the hot water pipe 16, generates steam, and is concentrated, and the concentrated solution passes through the dilute solution pipe 5, The solution enters the low-pressure stage absorber AL via the valve 6, is cooled by the cooling water in the cooling water pipe 32, and is sent again by the solution pump 1 to repeat the cycle.

On the other hand, the refrigerant vapor generated in the generator G passes through the steam pipe 14, reaches the condenser C, is cooled and condensed by the cooling water in the cooling water pipe 31, passes through the return pipe 30, pressure reducing valve 29, enters the low pressure stage evaporator EL, and enters the chilled water pipe. Part of the vapor is evaporated by the heat of the cold water 34, and the vapor enters the low pressure stage absorber AL through the steam pipe 15 and is absorbed into the solution.

The cold water in the cold water pipe 34 loses heat by evaporation of the refrigerant and becomes low temperature, and cold water at a lower temperature than the cooling water can be obtained from the outlet.

Some of the refrigerant sent by the refrigerant pump 7 is transferred to the branch pipe 1
2 and returns to the low pressure stage evaporator EL again to promote evaporation.

If there is a load fluctuation or other thermal fluctuation, it is detected by the temperature detector 35, 36 installed at the output end, and the three-way valve 2
0.23 to control the heat source hot water passing through the hot water pipes 16 and 17 to maintain the temperatures of hot water and cold water at required values.

However, in the conventional example as shown in FIG. The evaporator EL has the lowest temperature level of the refrigerant in the refrigerant cycle and is the lowest energy point for the refrigerant liquid.

Therefore, when refrigerant liquid is sent to the low-pressure stage evaporator EL, which may be the condenser C, it first lowers its own liquid temperature and enters a low-energy state, flashing and generating refrigerant vapor, reducing the load on the low-pressure stage absorber AL. It is increasing.

This low-temperature refrigerant liquid is pumped to the high-pressure stage evaporator EH, a location that requires high-temperature energy state, so it is necessary to preheat the refrigerant liquid by heating it from another heat source. Since the energy of the heat source of grass is lost, it is necessary to prevent this loss.

Further, since the superheated refrigerant from the generator G is separated from the high-temperature solution, it is led to the condenser C in a considerably high temperature state, and is discarded as it is into the cooling water of the condenser C.

The conventional method has the above-mentioned drawbacks, but the present invention provides a method for transferring high-temperature refrigerant liquid from the condenser to the low-pressure stage evaporator.
By exchanging heat with the low-temperature refrigerant liquid sent from the low-pressure stage evaporator to the high-pressure stage evaporator for cooling, this hybrid absorption type eliminates the above-mentioned drawbacks of conventional methods and can minimize flash loss in the evaporator. The purpose is to provide a heat pump.

Furthermore, the present invention recovers as much of the heat radiated to the condenser as possible by exchanging heat between the superheated refrigerant vapor from the generator and the refrigerant liquid sent from the low-pressure side evaporator to the high-pressure side evaporator. Another object of the present invention is to provide a hybrid absorption heat pump that can be used to preheat liquids.

The present invention has an absorber, a generator, an evaporator, a condenser, a dilute solution heat exchanger, and a fluid path connecting these, and maintains the generator and the condenser at an intermediate pressure, and maintains the generator and the condenser at a higher pressure. The generator and the high-pressure stage evaporator are provided with at least one stage of absorber and evaporator which are maintained at a pressure lower than the above-mentioned intermediate pressure. A cooling medium such as cooling water is introduced into a condenser and a low-pressure stage absorber to generate a thermal energy source such as high-temperature water that is hotter than the heat source, and a thermal energy source that is lower temperature than the cooling medium such as cooling water. In a hybrid absorption heat pump that can generate a cold heat source such as cold water or either one at the same time or as necessary, the refrigerant in the low-pressure stage evaporator is guided to the high-pressure stage evaporator. A refrigerant path is provided, and a heat exchanger is provided for performing heat exchange between the refrigerant in the refrigerant path and the refrigerant guided from the condenser to the low-pressure stage evaporator. It is a type heat pump.

To explain the present invention with reference to the drawings, FIG. 2 is a simplified diagram of the refrigerant system, and the difference from FIG. 1 is that heat exchangers 44 and 45 are provided. The other parts are the same as those shown in FIG.

The heat exchanger 45 combines the refrigerant in the refrigerant pipe 8, which is a refrigerant path that leads the refrigerant from the low-pressure evaporator EL to the high-pressure evaporator EH, and the refrigerant guided by the return pipe 30 to the condenser C or the low-pressure evaporator EL. It performs heat exchange between the

The heat exchanger 45 cools the refrigerant in the return pipe 30 before entering the low-pressure side evaporator EL, so that flash loss can be reduced.

Furthermore, this heat exchanger 45 further increases the temperature of the low-pressure side evaporator E.
Since the refrigerant L is preheated and sent to the high pressure side evaporator EH, effective use of heat is achieved.

The heat exchanger 44 exchanges heat between the refrigerant in the steam pipe 14, which is a refrigerant path from the generator G to the inside of the condenser C, and the refrigerant in the refrigerant pipe 8 to the low-pressure stage evaporator EL or the high-pressure stage evaporator EH. The heat that would be wasted in the cooling water in the condenser C is recovered and the refrigerant is preheated, making it possible to effectively utilize the heat.

The refrigerant pump 7 may also be used as a spray pump for uniformly distributing the refrigerant liquid onto the evaporator tube.

FIG. 3 shows another embodiment in which the heat exchanger 44 in FIG. 2 is installed in the condenser C.

For the above example, the high pressure stage evaporator EH or the low pressure stage evaporator E
In either case, a spray refrigerant pump T and a spray pipe 46 may be provided as shown in FIG. 4 to circulate the refrigerant liquid and perform spraying, if necessary, in order to improve heat transfer through the tube.

The present invention cools the refrigerant entering the low-pressure side evaporator from the condenser to minimize flash loss in the evaporator, preheats the refrigerant liquid without requiring energy from other heat sources, and provides a highly efficient hybrid system. It is possible to provide a type absorption heat pump, which has an extremely effective effect in terms of practical use and energy saving.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of a conventional example, FIG. 2 is a flow sheet of a refrigerant cycle according to an embodiment of the present invention, and FIGS. 3 and 4 are flow sheets of a refrigerant cycle according to an embodiment of the present invention. G... Generator, C... Condenser, AH.
...High pressure absorber, AL...Low pressure absorber, EH...High pressure evaporator, EL...
Low pressure stage evaporator, XH...High pressure stage heat exchanger, XL
...low pressure stage heat exchange gain, 1 ... solution pump, 2 ... intermediate concentration solution tube, 3 ... dilute solution tube, 4.6, 9 , 10, 11.19... Valve, 5... Concentrated solution tube, 7, 39... Refrigerant pump, 8, 40° 41.42... Refrigerant pipe, 1
2...Branch pipe, 13°14.15...
Steam pipe, 16, 17...Hot water pipe, 18.26.
...Inlet section, 20, 23... Three-way valve, 2
1... Inlet pipe, 22, 27... Outlet section, 24... Connection pipe, 28... Outlet pipe,
29...Reducing valve, 30...Return pipe, 3
1, 32... Cooling water pipe, 33... High temperature water pipe, 34... Cold water pipe, 35.36...
・Temperature detector, 37, 38...Liquid level detector, 4
4゜45...Heat exchanger, 46...Spray pipe.

Claims (1)

[Scope of Claims] 1. It has an absorber, a generator, an evaporator, a condenser, a dilute solution heat exchanger, and a fluid path connecting these, and maintains the generator and condenser at an intermediate pressure, and maintains the generator and the condenser at an intermediate pressure. and at least one stage of absorber and evaporator maintained at a pressure lower than the above-mentioned intermediate pressure. A heating medium such as cooling water is introduced into the condenser and a low-pressure stage absorber to generate a thermal energy source such as high-temperature water that is hotter than the heat source, and a cooling medium such as cooling water is produced. In a hybrid absorption heat pump that can generate a cold heat source such as low-temperature cold water at the same time or generate either one of them as necessary, the refrigerant in the low-pressure stage evaporator is transferred to the high-pressure stage evaporator. A hybrid suction type characterized by providing a refrigerant path leading to the refrigerant, and a heat exchanger for performing heat exchange between the refrigerant in the refrigerant path and the refrigerant led from the condenser to the low pressure stage evaporator. type heat pump. 2. It has an absorber, a generator, an evaporator, a condenser, a dilute solution heat exchanger, and a fluid path connecting these. The generator and condenser are maintained at an intermediate pressure, and at least one stage of absorber and evaporator is maintained at a higher pressure than the intermediate pressure, and at least one stage of absorber and evaporator is maintained at a pressure lower than the intermediate pressure. A heating medium, such as hot water, is introduced as a heat source to the generator and the high-pressure stage evaporator, and a cooling medium, such as cooling water, is guided to the condenser and the low-pressure stage absorber. In a hybrid absorption heat pump that can generate an energy source and generate a cold heat source such as cold water at a lower temperature than a cooling medium such as cooling water at the same time, or generate either one of them as necessary. The refrigerant in the low pressure stage evaporator is guided to the high pressure stage evaporator (a refrigerant path is provided, and heat exchange is performed between the refrigerant in the refrigerant path and the refrigerant led from the condenser to the low pressure stage evaporator). A heat exchanger that is provided with a heat exchanger and performs heat exchange between the refrigerant in the refrigerant path from the generator to the inside of the condenser and the refrigerant led from the low-pressure stage evaporator to the high-pressure stage evaporator. A hybrid absorption heat pump characterized by the provision of a heat pump.