JP3093472B2 - Absorption heat pump using low-temperature heat source - 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 heat pump using a low-temperature heat source, which uses heat of river water or sewage as a driving heat source.

[0002]

2. Description of the Related Art In a conventional absorption heat pump using river water or sewage treatment water, a double effect cycle cooling operation is performed by using river water or sewage treatment water as cooling water during cooling, and heating is performed during heating. Uses river water or sewage treatment water as a heat source and efficiently performs heat pump operation with a low single-effect cycle.

[0003] As described above, the reason for performing the heat pump operation by the single-effect cycle at the time of heating is that the water temperature of about 12 ° C held by a river or sewage is used as a heat source to obtain 45 ° C hot water for heating. When a heavy duty cycle is set up, the temperature of the lithium bromide solution used as the absorption solution rises, and its physical properties cause corrosion, crystallization, etc., and the pressure inside the device exceeds atmospheric pressure. It is.

[0004]

For this reason, C.I. during heating in a conventional heat pump using a low-temperature heat source is considered. O. P. Is as low as 1.4.

It is an object of the present invention to improve efficiency by operating a new cycle even during heating, while solving the problem of increasing the temperature of lithium bromide and the like. O. P.
Is increased to 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 And a refrigerant water generated in the evaporator through a first refrigerant vapor line. (1) leading to the absorber to absorb the solution, leading the dilute solution of the first absorber to the second generator via the first heat exchanger, and diluting the dilute solution with the steam and intermediate temperature generated by the third generator; Heated by the cooling water of the second absorber led through the blind line to separate into an intermediate concentration solution and refrigerant vapor, and the intermediate concentration solution separated in the second generator passes through the second heat exchanger. To the first generator, where the intermediate solution is heated to form a concentrated solution. Separating the medium vapor, the second heat exchanger,
The refrigerant vapor generated in the second generator is guided to the first absorber through the first heat exchanger, and the refrigerant vapor generated in the second generator is guided to the condenser through the second refrigerant vapor line to give latent heat to the hot water in the hot water line. Condensed, the condensed refrigerant is led to the evaporator to pump heat from the river water and sewage treatment water intake line, and the refrigerant vapor generated in the first generator is sent to the second absorber via the third refrigerant vapor line. Guiding the solution into the solution, guiding the dilute solution of the second absorber to the third generator via the third heat exchanger,
Here, it is heated and separated into a concentrated solution and a refrigerant vapor. 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 converted to the fourth refrigerant vapor. A new cycle operation of condensing by heating the solution in the second generator by introducing the solution into the second generator via the line can be performed at the time of heating. 4 cross the refrigerant vapor line in the middle, insert a cooling and heating switching valve at this intersection, switch the cooling and heating switching valve to the cooling side, to absorb the refrigerant vapor generated in the evaporator in the solution in the first absorber, The dilute solution in the first absorber passes through the first heat exchanger to the second generator, and is heated by the vapor generated from the first generator to separate the refrigerant vapor and the intermediate concentration solution. Fossil fuel through the exchanger to the first generator The concentrated solution in the first generator is further heated and separated into refrigerant vapor, and the concentrated solution in the first generator is led to the first absorber via the second heat exchanger and the first heat exchanger, and is generated in the first generator. The steam thus generated is introduced into the second generator via the cooling / heating switching valve, and condensed by providing latent heat in the second generator, and then guided to the evaporator via the condenser, where the steam generated in the second generator is generated. Is a low temperature heat source absorption heat pump configured to condense in a condenser, guide the evaporator, evaporate in the evaporator, and apply cooling to a chilled water line passing through the evaporator to perform cooling.

[0008]

[Action]

 ・ Heating cycle Switch the cooling / heating switching valve to the heating side.

The refrigerant vapor generated in the evaporator is absorbed in the solution in the first absorber. The dilute solution of the first absorber is
The solution is guided by the solution pump through the first heat exchanger to the second generator, and is heated by the steam generated by the third generator and the cooling water of the second absorber introduced through the intermediate temperature brine, and the intermediate concentration is obtained. Separated into solution and refrigerant vapor. The intermediate concentration solution separated in the second generator passes through the second heat generator by the solution pump and is led to the first generator. In the first generator, the intermediate solution is heated by the city gas fossil fuel and separated into a concentrated solution and a refrigerant vapor, and is guided to the first absorber through the second heat exchanger and the first heat exchanger.

[0010] The refrigerant vapor generated in the second generator is led to the condenser and condenses by giving the latent heat to the hot water line. The condensed refrigerant is guided to the generator and draws heat from the low-temperature heat source.

The refrigerant vapor generated in the first generator is absorbed in the solution in the second absorber. The dilute solution in the second absorber passes through the third heat exchanger by the solution pump,
Heated by the generator with fossil fuel or the like, it is separated into a 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 led to the second generator and heats and condenses the solution.

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

Cooling cycle The cooling / heating switching valve is switched to the cooling side.

[0014] The refrigerant vapor generated in the evaporator is absorbed in the solution in the first absorber. The dilute solution in the first absorber is led to the second generator through the first heat exchanger, heated by the vapor generated from the first generator, and separated into the refrigerant vapor and the intermediate concentration solution. The intermediate solution passes through the second heat exchanger and is led to the first generator, where it is heated by an open flame and separated into a concentrated solution and refrigerant vapor. The concentrated solution of the first generator passes through the second heat exchanger and the first heat exchanger, and is led to the first absorber. The steam generated in the first generator passes through the cooling / heating switching valve to the second
It is introduced into a generator, condenses by giving latent heat in this second generator, and is led to an evaporator via a condenser. The steam generated in the second generator is condensed in the condenser and is led to the evaporator.
The cold water is cooled by passing through the evaporator.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment 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 A first heat exchanger, 9 is a second heat exchanger, 10 is a third heat exchanger, 11 is a line for taking in river water and sewage treated water as a heat source of the evaporator 1, 12 is a first absorber 3 and a condenser. The hot water line 12 is connected to a radiator for heating.

Reference numeral 14 denotes an intermediate temperature brine for transferring the heat of absorption generated in the second absorber 6 to the second generator 5;
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 the first generator 4 and the second absorber. Third connecting 6
The refrigerant vapor line 18 is connected between the third generator 7 and the second generator 5.
Is a fourth refrigerant vapor line connected to the condenser 2 via the first and second refrigerant vapor lines 19 and 19 is a cooling / heating switching valve inserted at a portion where the third refrigerant vapor line 17 and the fourth refrigerant vapor line 18 intersect.

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

The cooling / heating switching valve 19 is switched to the heating side.

The refrigerant vapor generated in the evaporator 1 is led to the first absorber 2 to be absorbed in the solution, and the dilute solution in the first absorber 3 is sent to the second generator 5 via the first heat exchanger 8. The diluted solution is heated by the steam generated by the third generator 7 and the cooling water of the second absorber 6 to be separated into the intermediate concentration solution and the 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 be separated into a concentrated solution and a refrigerant vapor, and is guided to the first absorber 3 via the second heat exchanger 9 and the first heat exchanger 8, and the second generator 5 The condensed refrigerant is introduced to the evaporator 1 and taken in via the river water and sewage treatment water intake line 11 by guiding the refrigerant vapor generated in the above to the condenser 2 to give its latent heat to the hot water in the line 12. The heat is pumped up, and the refrigerant vapor generated in the first generator 4 is guided to the second absorber 6 to be absorbed in the solution, and the dilute solution in the second absorber 6 is subjected to the third generation via the third heat exchanger 10. The concentrated solution of the third generator 7 is returned to the second absorber 6 via the third heat exchanger 10 and is heated and separated into a concentrated solution and a refrigerant vapor. 7 is condensed by directing the refrigerant vapor of 7 to the second generator 5 and heating the solution in the second generator 5. That.

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

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.

[0023] 2.1 new cycle (the present invention) (1) evaporator temperature t _E 7.5 ° C. The pressure P _E 8 mmHg (2) the absorber first pressure P _E 8 mmHg outlet solution temperature t _A1 44 ° C. The second 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.

[0024] (1) evaporator temperature t _E 7.5 ° C. The pressure P _E 8 mmHg (2) the absorber pressure P _E 8 mmHg outlet solution temperature t _A1 45 ° C. (3) condenser temperature t _C 47 ° C. The pressure P _C 80 mmHg (4) Regenerator temperature t _G 98 ° C. Pressure _PCE 80 mmHg (5) Solution temperature Dilute solution ξ _L1 58.5% concentrated solution ξ _L2 61.5% 3. Calculation results The results obtained under the above cycle conditions are shown below.

3.1 New cycle heat pump efficiency COPh = 1.6 The boiler efficiency is set to 0.85.

3.2 Single-use cycle heat pump efficiency COPh = 1.4 The boiler efficiency is set to 0.85.

FIG. 2 shows a During diagram during the new cycle operation.

Next, an operation example of the cooling cycle will be described.

The cooling / heating switching valve 19 is switched to the cooling side.

The refrigerant vapor generated in the evaporator 1 is
The refrigerant is led to the first absorber 3 via the refrigerant vapor line 15 and is absorbed by the solution. The dilute solution in the first absorber 3 is guided to the second generator 5 through the first heat exchanger 8, and is heated by the vapor generated from the first generator 4 to be separated into refrigerant vapor and an intermediate concentration solution. The intermediate solution passes through the second heat exchanger 9 and is led to the first generator 4 where it is heated by an open flame and separated into a concentrated solution and a refrigerant vapor. The concentrated solution of the first generator 4 is supplied to the second heat exchanger 9,
It is led to the first absorber 3 through the heat exchanger 8.

The steam generated in the first generator 4 is introduced into the second generator 5 via the cooling / heating switching valve 19, where the second generator 5 gives latent heat and condenses. The steam generated in the second generator 5 is condensed in the condenser 2 and guided to the evaporator 1.

[0032]

According to the present invention, in the absorption heat pump utilizing a low-temperature heat source, the following effects are obtained by adopting the above-described configuration.

A. At the time of heating, a new cycle is adopted, the second absorber and the second generator are connected by an intermediate temperature blind line, and the refrigerant vapor generated in the third generator is passed through the second generator to the condenser. And the refrigerant vapor generated in the first generator is guided to the second absorber, so that the temperature of lithium bromide used as the refrigerant does not increase. Therefore, corrosion and crystallization of lithium bromide can be prevented, and the internal pressure of the device can be prevented from becoming higher than the atmospheric pressure.

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

C. The heating and cooling cycle can be easily performed by a cooling / heating switching valve.

[Brief description of the drawings]

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

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

[Explanation of symbols]

 DESCRIPTION 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 blind line 15 First refrigerant vapor line 16 Second refrigerant vapor line 17 Third refrigerant vapor line 18 Fourth refrigerant vapor line 19 Cooling / heating switching valve

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 15/00 303 F25B 30/06

Claims (1)

(57) [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. The system comprises a heat exchanger, river water serving as a heat source of the evaporator, a sewage treatment water intake line, a hot water line passing through a first absorber and a condenser, and a refrigerant vapor generated in the evaporator passing through a first refrigerant vapor line. To the first absorber to be absorbed in the solution. The diluted solution in the first absorber is led to the second generator via the first heat exchanger, and the diluted solution is vaporized by the third generator. Heated by the cooling water of the second absorber led through the intermediate temperature brine, separated into the intermediate concentration solution and the refrigerant vapor, and the intermediate concentration solution separated in the second generator is passed through the second heat exchanger. Via the first generator, where the intermediate solution is heated to form a concentrated solution. Separated into refrigerant vapor, a second heat exchanger,
The refrigerant vapor generated in the second generator is guided to the first absorber through the first heat exchanger, and the refrigerant vapor generated in the second generator is guided to the condenser through the second refrigerant vapor line to give latent heat to the hot water in the hot water line. The condensed refrigerant is led to the evaporator to draw heat from the river water and sewage treatment water intake line, and the refrigerant vapor generated in the first generator is sent to the second absorber via the third refrigerant vapor line. Guiding the solution into the solution, guiding the dilute solution of the second absorber to the third generator via the third heat exchanger,
Here, it is heated and separated into a concentrated solution and a refrigerant vapor. 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 converted to the fourth refrigerant vapor. A new cycle operation of condensing by heating the solution in the second generator by introducing the solution into the second generator via the line can be performed at the time of heating. 4 cross the refrigerant vapor line on the way, insert a cooling and heating switching valve at this intersection, switch this cooling and heating switching valve to the cooling side, to absorb the refrigerant vapor generated in the evaporator in the solution in the first absorber, The dilute solution in the first absorber passes through the first heat exchanger to the second generator, and is heated by the vapor generated from the first generator to separate the refrigerant vapor and the intermediate concentration solution. Fossil fuel through the exchanger to the first generator The concentrated solution in the first generator is further heated and separated into refrigerant vapor, and the concentrated solution in the first generator is led to the first absorber via the second heat exchanger and the first heat exchanger, and is generated in the first generator. The steam thus produced is introduced into the second generator via the cooling / heating switching valve, and condensed by giving latent heat in the second generator, and then guided to the evaporator via the condenser, and generated in the second generator. An absorption heat pump using a low-temperature heat source configured to condense steam in a condenser, guide the vapor to an evaporator, evaporate the vapor in the evaporator, and apply cooling to a chilled water line passing through the evaporator to perform cooling.