JPH0688651A - Low temperature heat source utilizing absorption heat pump - Google Patents

Abstract

PURPOSE:To make C.O.P. higher upon heating operation by operating a low temperature heat source utilizing absorption heat pump in a new cycle. CONSTITUTION:The refrigerant vapor produced by a first generator 4 is absorbed into a solution in a second absorber 6 and the resulting dilute solution in the second absorber 6 is conducted therefrom through a third heat exchanger 10 into a third generator 7. Such a solution is heated by fossil fuel to be separated into a concentrated solution and the refrigerant vapor, the concentrated solution in the third generator 7 is sent through the third heat exchanger 10 back into the second absorber 6, the refrigerant vapor in the third generator 7 is conducted through a second generator 5 into a condenser 1 and warm water is passed through a first absorber 3 and a condenser 2 to obtain the warm water having a temp. of 45 deg.C from a warm water line 12. In this way a rise in the temp. of lithium bromide will not be caused by the operation of the heat pump in a new cycle upon heating operation. Therefore, a highly efficient heating operation in the C.O.P. of 1.6 is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption heat pump using a low temperature heat source, which uses heat held by river water or treated sewage water as a driving heat source.

[0002]

2. Description of the Related Art In an absorption heat pump using conventional river water or treated sewage water, during cooling, the river water or sewage treated water is used as cooling water to perform a cooling operation in a double-effect cycle, and during heating. Uses river water or treated sewage water as a heat source, and operates a heat pump with a single-effect cycle that is low in efficiency.

As described above, the reason why the heat pump is operated by the single-effect cycle during heating is to use the water temperature of about 12 ° C., which the river water or the sewage-treated water has, as a heat source to obtain warm water of 45 ° C. for heating. Therefore, if a double-effect cycle is set up, the temperature of the lithium bromide solution used as the absorption solution will rise, and physical properties will cause corrosion, crystallization, and other problems, and the internal pressure of the equipment will exceed atmospheric pressure. This is because it will end up.

[0004]

Therefore, in the conventional heat pump using a low temperature heat source, the C.I. O. P. Is as low as about 1.4.

The object of the present invention is to improve the efficiency by operating in a new cycle even during heating, while eliminating the problem of high temperature of lithium bromide, thereby improving the efficiency of C.I. O. P. Is about 1.6.

[0006]

The structure of an absorption heat pump utilizing a low temperature heat source according to the present invention is as follows.

Evaporator, condenser, first absorber, first generator, second generator, second absorber, third generator, first heat exchanger, second heat exchanger, third heat exchange It consists of a condenser, river water that serves as a heat source of the evaporator, a sewage treatment water intake line, a hot water line that passes through the first absorber and a condenser, and guides refrigerant vapor generated in the evaporator to the first absorber and absorbs it into a solution. The diluted solution in the first absorber through the first heat exchanger to the second
The diluted solution is introduced into a generator, and the diluted solution is heated by the steam generated by the third generator and the cooling water of the second absorber to separate into an intermediate concentration solution and a refrigerant vapor, and the intermediate concentration solution separated in the second generator. To a first generator via a second heat exchanger, and in the first generator, the intermediate solution is heated to separate it into a concentrated solution and a refrigerant vapor, and the second heat exchanger and the first heat exchanger are connected to each other. It is led to the 1st absorber via, and the refrigerant vapor generated in the 2nd generator is led to a condenser, the latent heat is given to the warm water of a warm water line, it condenses, and the condensed refrigerant is led to a river water, Pump up heat from the sewage treatment water intake line.
The refrigerant vapor generated in the first generator is guided to the second absorber to be absorbed by the solution, and the dilute solution of the second absorber is guided to the third generator via the second heat exchanger where it is heated. The concentrated solution of the third generator is returned to the second absorber via the third heat exchanger and the refrigerant vapor of the third generator is guided to the second generator. An absorption heat pump using a low temperature heat source configured to condense by heating the solution in the second generator.

[0008]

Since the cooling cycle is the same as the known example, it is omitted and only the heating cycle will be described.

The refrigerant vapor emitted from the evaporator is absorbed by the solution in the first absorber. The dilute solution of the first absorber is
The solution pump is guided to the second generator through the first heat exchanger, and is heated by the steam generated by the third generator and the cooling water of the second absorber to be separated into the intermediate concentration solution and the refrigerant steam. The intermediate-concentration solution separated in the second generator passes through the second heat generator by the solution pump and is guided to the first generator. In the first generator, the intermediate solution is heated by the fossil fuel such as city gas and separated into a concentrated solution and a refrigerant vapor.
It is guided to the first absorber through the heat exchanger and the first heat exchanger.

Further, the refrigerant vapor generated in the second generator is guided to the condenser and gives its latent heat to the hot water line to be condensed. The condensed refrigerant is guided to the evaporator to draw up heat from the low temperature heat source.

Further, the refrigerant vapor generated in the first generator is absorbed by the solution in the second absorber. The dilute solution of the second absorber passes through the third heat exchanger by the solution pump,
It is heated by fossil fuel etc. by the generator and separated into concentrated solution and refrigerant vapor. The concentrated solution of the third generator passes through the third heat exchanger and returns to the second absorber. The refrigerant vapor of the third generator is guided to the second generator to heat and condense the solution.

By the above-mentioned cycle, the low temperature heat source is pumped up by the evaporator to raise the 40 ° C. hot water in the hot water line passing through the first absorber and the condenser to 45 ° C.

[0013]

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

1 is an evaporator, 2 is a condenser, 3 is a first absorber, 4 is a first generator, 5 is a second generator, 6 is a second absorber, 7 is a third generator, and 8 is 1st heat exchanger, 9 is a 2nd heat exchanger, 10 is a 3rd heat exchanger, 11 is river water used as a heat source of the evaporator 1, sewage treated water intake line, 12 is the 1st absorber 3 and a condenser. A hot water line passing through 2 is provided. The end of the hot water line 12 is connected to a heating radiator.

Reference numeral 14 denotes an intermediate temperature brine line for transferring the absorbed heat generated in the second absorber 6 to the second generator 5,
Reference numeral 15 is a first refrigerant vapor line connecting the evaporator 1 and the first absorber 3, 16 is a second refrigerant vapor line connecting the second generator 5 and the condenser 2, and 17 is a first generator 4 and the second absorber. Third connecting 6
Refrigerant vapor line, 18 is from the third generator 7 to the second generator 5
It is a fourth refrigerant vapor line connected to the condenser 2 via.

An operation example of the heating cycle based on the above device will be described below.

The refrigerant vapor generated in the evaporator 1 is guided to the first absorber 2 so as to be absorbed by the solution, and the dilute solution of the first absorber 3 is passed to the second generator 5 via the first heat exchanger 8. This dilute solution is heated by the steam generated by the third generator 7 and the cooling water of the second absorber 6 to separate into an intermediate concentration solution and a refrigerant vapor, and the intermediate concentration solution separated in the second generator 5 To the first generator 4 via the second heat exchanger 9,
In the generator 4, the intermediate solution is heated to separate it into a concentrated solution and a refrigerant vapor, which is led to the first absorber 3 via the second heat exchanger 9 and the first heat exchanger 8, and then the second generator 5 The refrigerant vapor generated in 1 is introduced to the condenser 2 to give its latent heat to the hot water in the line 12 to be condensed, and the condensed refrigerant is introduced to the evaporator 1 to be taken in via the river water / sewage treated water intake line 11. The heat is pumped up, the refrigerant vapor generated in the first generator 4 is guided to the second absorber 6 to be absorbed by the solution, and the dilute solution of the second absorber 6 is generated through the third heat exchanger 10 for the third generation. The concentrated solution of the third generator 7 is returned to the second absorber 6 via the third heat exchanger 10, and is then heated to separate into the concentrated solution and the refrigerant vapor. The refrigerant vapor of No. 7 is introduced into the second generator 5 and the solution in the second generator 5 is heated to be condensed. That.

Next, an example of calculation conditions of the absorption heat pump using sewage treatment water using the above embodiment will be shown.

1. Initial conditions (1) Cold water temperature inlet 12 ° C outlet 9 ° C (2) Hot water temperature inlet 40 ° C outlet 45 ° C 2. Cycle conditions used for calculation The cycle conditions determined by the initial conditions are shown below.

2.1 New Cycle (Invention) (1) Evaporator temperature t _E 7.5 ° C. Pressure P _E 8 mmHg (2) Absorber 1st pressure P _E 8 mmHg Outlet solution temperature t _A1 44 ° C. 2nd the pressure P _CE 40 mmHg outlet solution temperature t _A2 50 ℃ (3) condenser temperature t _C 47 ° C. the pressure P _C 80 mmHg (4) regenerator first temperature t _G 138 ° C. the pressure P _CE 400 mmHg second temperature t _G 95 ° C. the pressure P _C 80 mmHg third temperature t _G 140 ° C. the pressure P _C 700 mmHg (5) the solution temperature low-stage diluted solution xi] _L1 58.5% intermediate solutions xi] _L2 60.4% concentrated solution xi] _L3 61.5% High-stage side Dilute solution ξ _H1 52.0% Concentrated solution ξ _H2 55.5% Next, single-effect cycle conditions (conventional example) are shown below.

(1) Evaporator temperature t _E 7.5 ° C. Pressure P _E 8 mmHg (2) Absorber pressure P _E 8 mmHg Outlet solution temperature t _A1 45 ° C. (3) Condenser temperature t _C 47 ° C. Pressure P _C 80 mmHg (4) Regenerator temperature t _G 98 ° C Pressure P _CE 80 mmHg (5) Solution temperature Dilute solution ξ _L1 58.5% Concentrated solution ξ _L2 61.5% 3. Calculation Results The results of the above cycle conditions are shown below.

3.1 New Cycle Heat Pump Efficiency COPh = 1.6 Boiler efficiency is 0.85.

3.2 Single-effect cycle Heat pump efficiency COPh = 1.4 Boiler efficiency is 0.85.

FIG. 2 shows a Duhring diagram during the above new cycle operation.

[0025]

EFFECTS OF THE INVENTION The present invention has the following effects by adopting the above-mentioned structure in the absorption heat pump utilizing the low temperature heat source.

A. During heating, a new cycle is adopted, the second absorber and the second generator are connected by an intermediate temperature brine line, and the refrigerant vapor generated in the third generator is passed through the second generator to the condenser. By introducing the refrigerant vapor generated in the first generator to the second absorber, the temperature of lithium bromide used as the refrigerant does not rise. Therefore, corrosion and crystallization of lithium bromide can be prevented.

B. By adopting a new cycle during heating, C.I. O. P. Can be increased to about 1.6,
This value is for a conventional low temperature heat source heat pump,
C. when operating in a single-effect cycle O. P. = 1.4
It is a great improvement in efficiency compared to the degree.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment according to the present invention.

FIG. 2 is an explanatory diagram of a Duhring diagram.

[Explanation of symbols]

 1 Evaporator 2 Condenser 3 1st absorber 4 1st generator 5 2nd generator 6 2nd absorber 7 3rd generator 8 1st heat exchanger 9 2nd heat exchanger 10 3rd heat exchanger 11 River water or sewage treated water intake line 12 Hot water line 14 Intermediate temperature brine line 15 First refrigerant vapor line 16 Second refrigerant vapor line 17 Third refrigerant vapor line 18 Fourth refrigerant vapor line

Claims (1)

[Claims] 1. An evaporator, a condenser, a first absorber, a first generator, a second generator, a second absorber, a third generator, a first heat exchanger, a second heat exchanger, and a third heat exchanger. It consists of a heat exchanger, river water that serves as a heat source for the evaporator, a sewage treatment water intake line, a hot water line that passes through the first absorber and a condenser, and guides refrigerant vapor generated in the evaporator to the first absorber to form a solution. And the diluted solution in the first absorber is passed through the first heat exchanger to the second
The diluted solution is introduced into a generator, and the diluted solution is heated by the steam generated by the third generator and the cooling water of the second absorber to separate into an intermediate concentration solution and a refrigerant vapor, and the intermediate concentration solution separated in the second generator. To a first generator via a second heat exchanger, and in the first generator, the intermediate solution is heated to separate it into a concentrated solution and a refrigerant vapor, and the second heat exchanger and the first heat exchanger are connected to each other. It is led to the 1st absorber via, and the refrigerant vapor generated in the 2nd generator is led to a condenser, the latent heat is given to the warm water of a warm water line, it condenses, and the condensed refrigerant is led to a river water, The heat from the sewage treated water intake line is pumped up, the refrigerant vapor generated in the first generator is guided to the second absorber and absorbed in the solution, and the dilute solution in the second absorber is passed through the third heat exchanger. Leading to a third generator, where it is heated to separate it into a concentrated solution and refrigerant vapor, The concentrated solution of the 3 generator is returned to the 2nd absorber via the 3rd heat exchanger, and the refrigerant vapor of the 3rd generator is guided to the 2nd generator to heat the solution in this 2nd generator. An absorption heat pump that uses a low temperature heat source configured to be condensed by.