JPS5812507B2 - Hybrid type 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 7, 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 evaporator EL have a pressure reducing valve 29 and a return pipe 30.
Connected by

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 and 17 are respectively installed in the generator G and the high-pressure stage evaporator EH, and an inlet pipe 21 having a valve 19 and a branch to a three-way valve 20 is connected to the inlet part 18 of the hot water pipe 16, 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 section 26 of the hot water pipe 17, and the other port is connected to an outlet pipe 28 connected to the outlet section 27 and further connected to the heat exchanger Xs.

The condenser C and the low-pressure stage absorber AL are equipped with a cooling water pipe 3L32 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 3B are liquid level detectors that respectively control the valve 10 or the valve 6.

The refrigerant is heated by the heat exchangers Xs and 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 communicate with each other, 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, hot water can be passed through the hot water pipes 16 and 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 valves 9 and 10 by the refrigerant pump 7 and into the hot water pipe 1.
It is heated and evaporated by the hot water of step 7, 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 evaporation 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 EI, where evaporation is promoted.

If there is a load change or other thermal change, it is detected by the temperature detectors 35 and 36 installed at the output end, and the three-way valve 2
0 and 23 to control the heat source hot water passing through the hot water pipes 16 and 17 to maintain the temperatures of high temperature water and cold water at required values.

However, in the conventional example shown in Fig. 1 as described above, all of the refrigerant liquid condensed in the condenser C is sent to the low-pressure stage evaporator EL, from where it is distributed to the necessary locations; The stage evaporator EL has the lowest refrigerant temperature level in the refrigerant cycle and is the lowest energy point for the refrigerant liquid.

Therefore, when the refrigerant liquid is sent from the condenser C to the low-pressure stage evaporator EL, it first lowers its own liquid temperature and enters a low-energy state, so it flushes and generates 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 evaporator EH, a location that requires a high-temperature energy state, and is heated by another heat source to the high-pressure evaporator EH.
It is necessary to prevent losses due to preheating sent to H.

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 improves the conventional method by distributing the required amount of the refrigerant liquid condensed in the condenser to the low-pressure evaporator and the high-pressure evaporator and sending them directly. The object of the present invention is to provide a hybrid absorption heat pump capable of minimizing flash losses in the evaporator, while eliminating the above-mentioned drawbacks of the present invention.

In addition, in the present invention, the refrigerant liquid is supplied to the high-pressure side evaporator not from the low-pressure stage evaporator, but by sending relatively high-temperature refrigerant liquid directly from the condenser to the high-pressure stage evaporator, thereby eliminating the need for preheating. A second objective is to provide such a hybrid absorption heat pump.

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 produce a thermal energy source such as high-temperature water that is hotter than the heat source and a cooling medium 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 needed, a portion of the refrigerant flowing out from the condenser is directly supplied to the high pressure stage. This hybrid absorption heat pump is characterized in that the flow rate of refrigerant introduced into the evaporator and flowing into the low-pressure stage evaporator is controlled to the minimum necessary.

To explain the present invention with reference to the drawings, the example shown in FIG. 2 has roughly the same configuration as that in FIG. , the refrigerant liquid from the condenser C is divided by a refrigerant pump 39 into a portion sent directly to the high-pressure stage evaporator EH via the refrigerant pipe 8, and a portion sent to the low-pressure stage evaporator EL due to gravity and pressure difference, By controlling the flow rate of the refrigerant pump 39 and the flow rate of the valve 9 or 10, the high pressure stage evaporator EH and the low pressure stage evaporator EL
By changing the distribution ratio of refrigerant liquid to the low-pressure stage evaporator EL, the amount of refrigerant to the low-pressure stage evaporator EL can be kept to the minimum necessary, thereby minimizing flash loss in the evaporator.

Refrigerant cycles in various embodiments will be explained below.

FIG. 3 is a simplified system diagram of the refrigerant cycle in FIG. 2.

FIG. 4 shows another embodiment in which the refrigerant liquid sent out by the refrigerant pump 39 is distributed to the high pressure stage evaporator EH and the low pressure stage evaporator EL.

In that case, one or both of valves 9 and 11 may be provided to adjust the distribution ratio, if necessary.

Although this type of valve is not particularly shown in the examples below, if provided, the distribution ratio and flow rate can be easily adjusted.

FIG. 5 shows another embodiment, in which for the high pressure stage evaporator EH,
Condenser C is placed at a height that allows for a gravitational drop that overcomes the pressure difference.
In addition to having the effects of the above-mentioned example, the refrigerant liquid can be supplied without particularly requiring a refrigerant pump.

FIG. 6 shows another embodiment, in which the refrigerant of the high-pressure stage evaporator BH is circulated and sprayed by a refrigerant pump 39 through refrigerant pipes 40, 41.8, and an ejector 43 is provided in the circulation path. A refrigerant pipe 42 from the condenser C is connected to the suction side.

Due to the flow in this circulation path, the refrigerant in the condenser C is supplied to the high pressure stage evaporator EH, and is also distributed to the low pressure stage evaporator EL due to the pressure difference and gravity.

FIG. 7 shows another embodiment, which has the same configuration as that shown in FIG. Heat recovery is performed, and in addition to the effects of the above-described embodiments, waste heat that would be wasted in the cooling water is recovered and the heat exchange coefficient is improved.

FIG. 8 shows another embodiment, in which the heat exchanger 4 in FIG.
4 is provided in the condenser C.

FIG. 10 shows another embodiment of the heat exchanger 44 in FIG.
is installed in the condenser C.

For the above examples, the high pressure stage evaporator EH or the low pressure stage generator E
In either case, in order to improve heat transfer in the tube, a spray refrigerant pump 7 and a spray pipe 46 may be provided as shown in FIG. 9 to circulate the refrigerant liquid and perform spraying, if necessary.

The present invention optimizes the refrigerant flow rate to the low-pressure stage evaporator to minimize flash loss in the low-pressure side evaporator, saves energy for preheating the refrigerant, and is a hybrid absorption type with high operational efficiency. It is possible to provide a heat pump, which has an extremely large 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 an embodiment of the present invention, and FIGS. 3 to 9 are flow sheets of refrigerant cycles of different embodiments of the present invention. G... Generator, C... Condenser, AH.
...High pressure stage absorber, AL...Low pressure stage absorber, EH...High pressure stage evaporator, BL...Low pressure stage evaporator, xH...・・High pressure stage heat exchanger, xL・
...low pressure stage heat exchanger, 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, 12... Branch pipe, 13, 14, 15...
...Steam pipe, 16,17...Hot water pipe, 18,
26... Entrance section, 20, 23...
Three-way valve, 21...Inlet pipe, 22, 27...
...Exit part, 24...Connection pipe, 28...
... Outlet pipe, 29 ... Pressure reducing valve, 30 ...
... Return pipe, 31, 32 ... Cooling water pipe, 33.
...High temperature water pipe, 34...Cold water pipe, 35,
36...Temperature detector, 37, 3B...Liquid level detector, 39...Refrigerant pump, 43...
...Ejector, 44...Heat exchanger, 46...
...Spray tube.

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 the condenser at an intermediate pressure. at least one stage of absorber and evaporator held at a high pressure and at least one stage of absorber and evaporator held at a pressure lower than said intermediate pressure; A heating medium such as cooling water is introduced into the condenser and a low-pressure stage absorber, and a cooling 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 higher in temperature than the heat source, and a cooling medium such as cooling water is 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, a portion of the refrigerant flowing out from the condenser is directly A hybrid absorption heat pump characterized in that the flow rate of refrigerant introduced into the high-pressure stage evaporator and flowing into the low-pressure stage evaporator is controlled to the necessary minimum. 2 the condenser is located higher than the high pressure stage evaporator;
The heat pump according to claim 1, wherein the refrigerant liquid is supplied by gravity and an internal pressure difference. 3. 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. At least one stage of absorber and evaporator is provided at both sides, and at least one stage of absorber and evaporator is maintained at a pressure lower than the above-mentioned intermediate pressure, and a heating medium such as hot water is introduced as a heat source to the generator and the high-pressure stage evaporator. 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 higher temperature than the heat source, and to generate a thermal energy source such as high-temperature water that is lower temperature than the cooling medium such as cooling water. In a hybrid absorption heat pump that can generate a cold source and generate either one at the same time or as necessary, the refrigerant liquid in the high-pressure stage evaporator is sucked into the high-pressure stage evaporator again. a circulation circuit having a pump for supplying and circulating the air, an ejector is inserted into the discharge side circuit of the pump,
A hybrid absorption heat pump characterized in that the refrigerant liquid from the condenser is guided to the suction port of the ejector. 4 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 a small At least one stage of absorber and evaporator is provided at both sides, and at least one stage of absorber and evaporator is maintained at a pressure lower than the above-mentioned intermediate pressure, and a heating medium such as hot water is introduced as a heat source to the generator and the high-pressure stage evaporator. 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 higher temperature than the heat source, and to generate a thermal energy source such as high-temperature water that is lower temperature than the cooling medium such as cooling water. In a hybrid absorption heat pump that is capable of generating a cold heat source and generating either one at the same time or as necessary, a portion of the refrigerant flowing out from the condenser is directly supplied to the high-pressure stage evaporator. and control the flow rate of refrigerant flowing into the low pressure stage evaporator to the necessary minimum, so that the refrigerant in the refrigerant path leading from the generator to the inside of the condenser and the refrigerant being guided from the condenser to the high pressure stage evaporator. A hybrid absorption heat pump characterized by being equipped with a heat exchanger that exchanges heat with a refrigerant.