WO2009140858A1

WO2009140858A1 - Absorption type heat supply system and heat supply method

Info

Publication number: WO2009140858A1
Application number: PCT/CN2009/000538
Authority: WO
Inventors: 苏庆泉
Original assignee: Su Qingquan
Priority date: 2008-05-20
Filing date: 2009-05-19
Publication date: 2009-11-26
Also published as: CN101586890B; CN101586890A

Abstract

An absorption type heat supply system and a heat supply method are disclosed. The heat supply system includes a generator (21) in which a generating heat exchanger (25) is provided and an absorbing solution is filled, an absorber (22) in which an absorbing heat exchanger (26) is provided and the absorbing solution is filled, a vapor channel (23) which communicates with the generator (21) and the absorber (22), and a conveying device for absorbing solution for conveying the absorbing solution between the generator (21) and the absorber (22), which connecting with the generator (21) and the absorber (22). The concentration of the absorbing solution in generator (21) is lower than that in absorber (22). The vapor of working substance is produced by an external thermal source heating the lower concentration absorbing solution in generator (21). The vapor of working substance is absorbed by the higher concentration absorbing solution in the absorber (22), and the absorbing heat is released in high temperature, thereby a high quality heat is exported.

Description

Absorption heating system and heating method

The present invention relates to a heating technology in the field of thermal engineering, and more particularly to an absorption heating system composed of two units and a heating method. Background technique

Referring to FIG. 1 , the existing absorption heat pump cycle heating system mainly comprises: a generator 11 with a heat exchanger 110 built therein, a condenser 12 with a condensation heat exchanger 120 therein, and an internal evaporation heat exchanger. The evaporator 13 of 130 and the absorber 14 of the absorption heat exchanger 140 are additionally provided with an absorption solution from the heat exchanger 150, an absorption solution pump, and a throttle (not shown) as an auxiliary device. The generator 11 and the condenser 12 are connected by a vapor passage 19, and the evaporator 13 and the absorber 14 are connected by a vapor passage 18. The absorption solution is circulated between the generator 11 and the absorber 14 through the absorption solution conduits 16 and 15. ^:: The working process of the existing absorption heat pump circulating heating system includes: (1) heating from the absorber 14 by heating the generator enthalpy (such as water vapor, hot water, gas, etc.) The concentrated lithium bromide solution is evaporated and the water in the lithium bromide solution is evaporated, and the resulting concentrated lithium bromide solution is circulated to the absorber 14. (2) The water vapor enters the condenser 12 through the vapor passage 19, and is condensed into the condensed water by the cooling medium in the condensing heat exchanger 120. (3) The condensed water enters the evaporator 13 through the condensed water pipe 17, and the same or another driving heat source is passed through the evaporating heat exchanger 130 to change the condensed water from the condenser into water vapor. (4) The above-mentioned water vapor enters the generator 14 through the vapor passage 18, is absorbed by the concentrated desalinated lithium solution from the generator 11, and generates absorption heat, while the concentration of the lithium bromide solution is lowered, and the low concentration lithium bromide solution is circulated to the generator 11 The heat of absorption is used to heat the working fluid (generally water) in the heat exchanger 140, so that the temperature of the working medium is increased, and is output as a higher-grade thermal energy than the above-mentioned driving heat source (when the working medium is In the case of water, it can be output in the form of water vapor) to achieve the purpose of outputting heat energy to the absorption heat pump circulating heating system.

In the conventional absorption heat pump circulation system described above, in order to concentrate the lithium telluride solution in the generator 11, the lithium bromide solution must be heated by the heat exchanger 110 to obtain a high concentration lithium bromide solution, so The heat pump circulation system must drive a heat source from a high-temperature heat source from the outside. This not only limits the heating factor of the heat pump cycle system, The application of the heat pump circulation system is also limited in areas where heat source resources are scarce. Summary of the invention

The main object of the present invention is to overcome the problems existing in the existing absorption heat pump cycle heating system, and to provide an absorption heating system and a heating method, and the technical problem to be solved is to realize the absorption type by using two units. Heating, tubular heating system structure, more suitable for practical, and has industrial value.

The object of the present invention and solving the technical problems thereof are achieved by the following technical solutions. An absorption heating system according to the present invention, comprising: a generator having a heat exchanger formed therein, the generator being filled with an absorption solution; and an absorber having an absorption heat exchanger therein, The absorber is filled with an absorbing solution; and a vapor passage connecting the generator and the absorber; the concentration of the absorbent in the absorbing solution in the generator is lower than the concentration of the absorbing agent in the absorbing solution in the absorber.

The object of the present invention and solving the technical problems thereof can be further realized by the following technical measures. _:; Preferred, absorption heating system according to an embodiment of the present invention, further comprising conveying means absorbing solution: between the opposed connected to said absorber and said generator, the generator and the absorber for Transfer the absorption solution.

Preferably, the absorption heating system of the embodiment of the present invention, wherein the absorption solution is composed of a working medium and an absorbent, the working medium is one of water, methanol and ethanol or a mixture of several substances; The absorbent is one or a mixture of LiBr, LiCl, LiNO ₃ , ZnCl ₂ and CaCl ₂ .

Preferably, the absorption heating system of the embodiment of the invention, wherein the absorber is placed inside the generator, or the generator is placed inside the absorber.

Preferably, the absorption heating system of the embodiment of the invention, wherein the generator and the absorber have a common side wall, and the steam passage is a through hole formed in the side wall.

The object of the present invention and solving the technical problems thereof are achieved by the following technical solutions. An absorption heating method according to the present invention, which adopts the above absorption heating system, the method comprising: heating a low concentration absorption solution with a low temperature heat source and generating working fluid vapor in the generator; The steam is sent to the absorber through the steam passage, the working medium vapor is absorbed by the high concentration absorption solution in the absorber, releasing the high temperature absorption heat; and performing heat exchange in the absorber, and the above absorption heat is outward Output. Preferably, the absorption heating method of the embodiment of the present invention further comprises: stopping adding when the difference between the concentration of the absorbing solution in the generator and the concentration of the absorbing solution in the absorber is less than a preset value _; Absorbing solution; transporting the ϋ'ΐ solution in the generator to the absorber; cooling the absorbing solution in the absorber to cause crystallization of the absorbent; delivering the supernatant in the absorber to the generator.

Preferably, the absorption heating method of the embodiment of the invention, wherein the pressure in the generator and the absorber is the same.

Preferably, the absorption heating method of the embodiment of the invention, wherein the absorption solution in the absorber is a saturated solution.

The present invention has significant advantages and advantageous effects over the prior art. As can be seen from the above technical solutions, the heating system proposed by the present invention has a simple structure and is easy to manufacture and maintain as compared with the existing absorption heating system. In addition, the difference in concentration of the absorbing solution in the generator and the absorber can be maintained at a relatively large value, so that the heat source grade of the external output can be increased more, and a larger temperature rise can be obtained. The heating system and the heating method of the present invention have only one evaporator and a condenser, and only have: a low-temperature heat source input process and a high-temperature heat source output process without a cooling process, and thus have a significantly higher absorption than the existing absorption type. Heating coefficient of the heat pump circulation system. The above description is only an overview of the technical solutions of the present invention. In order to more clearly understand the technical means of the present invention, and can be implemented in accordance with the internals of the specification, the following detailed description of the preferred embodiments of the present invention Rear. DRAWINGS

1 is a flow chart of a conventional absorption heat pump circulation system.

Figure 2 is a schematic view showing the structure of an absorption type heating system of Embodiment 1 of the present invention.

Figure 3 is a schematic view showing the structure of an absorption type heating system of Embodiment 2 of the present invention.

Figure 4 is a schematic view showing the structure of an absorption type heating system of Embodiment 3 of the present invention.

Figure 5 is a flow chart showing the process of absorbing solution regeneration in the heating method of Embodiment 4 of the present invention. The best way to achieve your invention

In order to further illustrate the technical means and efficacy of the present invention for achieving the intended purpose of the invention, the specific embodiments, structures, features and the like of the absorbing heating system according to the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Efficacy, detailed description as follows.

Referring to FIG. 2, it is a schematic structural view of an absorption type heating system according to Embodiment 1 of the present invention. The heating system includes: a generator 21, an absorber 22, a steam passage 23, and a liquid supply pump 24. The generator 21 is filled with an absorbing solution: the absorbing solution is composed of a working substance and an absorbent. A generator heat exchanger 25 is provided in the generator 21, and the generating 'heat exchanger 25 is connected to an external low temperature heat source for heating the absorption solution. The absorber 22 is filled with an absorbing solution having the same working fluid and absorbent as the absorbing solution in the generator 21, but the concentration of the absorbent is higher than the concentration of the absorbing agent in the generator 21, preferably. The absorbing solution in the absorber 22 is a saturated solution (or a supersaturated solution, that is, a crystallization of the absorbent). An absorption heat exchanger 26 is provided in the absorber 22 for transferring the heat of absorption in the absorber 22 to an external working medium (water, or heat medium) in the absorption heat exchanger 26 for supply. User use. The steam passage 23 is connected to the generator 21 and the absorber 22 for conveying the working fluid vapor generated in the generator 21 to the absorber 22. The liquid supply pump 24 is connected to the generator 21 and the absorber 22 through a pipe for conveying the absorption solution between the generator 21 and the absorber 22. The operation of the absorption heating system of the present embodiment is that the external low-temperature heat source heats the absorption solution in the generator 21 through the heat exchanger 21 to generate working vapor, which enters the absorber through the steam conduit 23. (shown in phantom: FIG), since the concentration of the absorbing solution in the absorber 22 is higher than the generator 21 of absorption solution ^{concentration:} degrees, under equal pressure conditions, in the absorbing solution in the absorber 22 may be more Absorption at high temperatures: The working fluid vapor from the generator 21, thereby releasing the heat of absorption at this higher temperature. In the suction heat exchanger 22, an external working medium is introduced into the heat exchange with the absorbing solution, so that the above-mentioned absorption tropic can be taken out of the absorber, thereby achieving the purpose of external heating. In the above absorption solution, the working substance is one of water, sterol and ethanol or a mixture of several substances; the absorbent is one or more of LiBr, LiCl, LiN0 ₃ , ZnC ₂ and CaC ₂ a mixture of substances.

Referring to FIG. 3, it is a schematic structural view of an absorption heating system according to Embodiment 2 of the present invention. The present heating system includes a generator 31, an absorber 32, a steam passage 33, and a liquid supply pump 34, and the respective components described above function the same as in the first embodiment. The generator 31 is filled with an absorbing solution and is provided with a heat exchanger 35. The absorber 32 is filled with an absorbing solution having a higher concentration of the absorbent than the absorbing agent of the absorbing solution in the generator 31, and an absorbing heat exchanger 26 is disposed in the absorber 32. The generator 31 and absorber 32 have a common top plate and side walls 37 which are insulated walls that prevent heat exchange between the generator 31 and the absorber 32. A through hole is formed in the upper portion of the side wall 37 as a steam passage 37 for flowing the working medium vapor generated by the generator 31 into the absorber 32 and being absorbed by the high concentration absorbing solution therein. The absorption heat generated in the absorber 33 is absorbed by The external working fluid in the heat exchanger 36 is output to achieve the purpose of heating.

Referring to Fig. 4, it is a schematic structural view of an absorption type heating system according to Embodiment 3 of the present invention. The heating system includes: a generator 41, an absorber 42, a steam passage 43 and a liquid supply pump 44, and the functions of the above components are the same as those of the first embodiment. The generator 41 is filled with an absorbing solution and is provided with a heat exchanger 45. The absorber 42 is filled with an absorbing solution having a higher concentration of the absorbent than the absorbing agent of the absorbing solution in the generator 41, and the absorber 42 is provided with a absorbing heat exchanger 46. The generator 41 in this embodiment is placed in the absorber 42, so that the generator 41 is kept open, so that the generated working fluid vapor flows to the surface of the absorption solution in the absorber 42, thereby being The absorption solution absorbs and releases the heat of absorption, and the absorption heat is output to the outside through the absorption heat exchanger 46 to achieve the purpose of heating. The generator 41 shown in the drawing is connected to the passage of the absorber 42 for conveying the absorption solution in the generator 41 to the generator 42, on which a valve 47 is provided for controlling the conduction of the pipe and shut down. The liquid supply pump 44 is also coupled to the 'generator 41 and the absorber 42' for conveying the absorption solution in the upper portion of the absorber 42 to the generator 41 having a higher position. Optionally, the structure of the heating system of Embodiment 3 is unchanged, and the generator 41 is filled with a high concentration: absorption solution, and the absorber 42 is filled with a low concentration absorption solution through the absorption heat exchanger 42. The heat exchanger 45 can be externally heated by the external low temperature heat source.

Embodiment 4 of the present invention also provides a heating method which is implemented by the absorption type heating system shown in Embodiment 1 or 2. The method comprises: using an external low-temperature heat source to generate a working medium vapor by generating a low-concentration absorption solution in the heat exchanger to generate working fluid vapor; the working medium vapor enters the absorber through the steam passage; in the absorber, from the occurrence The working fluid vapor is absorbed by the high concentration absorption solution and releases the absorbed heat. Since the concentration of the absorbing solution in the absorber is higher than the concentration of the absorbing solution in the generator, the absorbing solution in the absorber can achieve a higher temperature than the absorbing solution of the generator in the case where the pressure in the absorber and the generator are equal. The working fluid is absorbed and the heat is absorbed. The above-mentioned absorption heat is delivered to an external user by absorbing the external working medium in the heat exchanger, thereby achieving the purpose of heating. At this time, since the operating temperature of the absorber is higher than the operating temperature of the generator in the above process, the temperature of the external mass output from the absorption heat exchanger can be higher than the temperature of the external low temperature heat source that generates the heat exchanger input, thereby Provides higher grades of heat. According to the heating method of the present embodiment, the difference between the temperature of the low-temperature heat source externally supplied and the temperature of the high-temperature heat source supplied to the outside, that is, the temperature rise and the concentration of the generator absorbing solution and the absorber absorbing solution Poor. The greater the difference in concentration, the greater the temperature rise. As the heating process progresses, the absorption solution in the absorber gradually decreases in concentration due to the continuous absorption of the working fluid vapor, and the solution in the generator is continuously evaporated due to the working medium, and the temperature is gradually increased. Therefore, the difference in concentration between the absorber absorption solution and the generator absorption solution is gradually reduced. When the concentration difference is less than a certain preset value, the heating is stopped. At this time, it is necessary to carry out a regeneration process of the absorption solution. Referring to Figure 5, the absorption solution in the generator is sent to the absorber through the liquid feeding pump, and then the low temperature cooling is introduced into the generator to cool the absorption solution in the absorber and absorb as the temperature decreases. The absorbing solution in the device will reach saturation. When the temperature is further lowered, the absorbent in the absorbing solution will crystallize and deposit at the bottom of the absorber, and the concentration of the absorbent in the supernatant will decrease. When the temperature of the absorption solution in the absorber is further reduced to a certain extent, a large amount of crystals are deposited on the bottom of the absorber, and when the concentration of the absorbent of the supernatant is lowered to a certain value, the cooling can be stopped, and the supernatant is passed through the liquid supply. The pump is delivered to the generator. At this point, the concentration of the absorbing solution in the absorber is increased and the concentration of the absorbing solution in the generator is lowered, thereby completing the regeneration process of the absorbing solution, after which the next heating process can be performed. Since the absorption solution has a smaller specific heat, the cooling amount is smaller, and since the crystallization heat of the absorbent is much smaller than the heat of evaporation of the working medium, the regeneration process of the absorption solution is only required: a small amount of cooling is required. In the embodiment, the working fluid is one of water, sterol and ethanol, or a mixture of several physical shields; the absorbent is one or more of LiBr, LiCl, LiN0 ₃ , ZnCl ₂ and CaCl ₂ a mixture of substances.

Instance

This example employs the heating method of Example 4, using wet steam having a saturation temperature of 75 ° C as an external low temperature heat source. The absorption solution uses water as the working medium, and lithium bromide is used as the absorbent. The initial concentration of LiBr in the absorption solution of the generator is 56%, and the LiBr termination mass concentration is 58%. The initial mass concentration of LiBr in the absorption solution in the absorber is 71%, and the heat exchange rate of the absorber during the absorption process is always maintained at around 110°C by the heat exchange between the external working medium and the absorption solution. Since this example always retains LiBr crystals at the bottom of the absorber, the crystals are continuously dissolved during the absorption process, so that the LiBr mass concentration of the absorption solution in the absorber is always maintained at about 71% of the saturated dissolution state of 110 °C. When the mass concentration of LiBr absorbed in the generator is increased to about 58%, the operation of the absorber The temperature will begin to decline, at which point the absorption process ends and the process begins. First, the liquid feeding pump is started to deliver the absorption solution in the generator to the absorber, and then the absorption solution in the absorber is cooled. In this example, a - 15 3⁄4 antifreeze is used as a supply of cold, and the antifreeze is passed to an absorption heat exchanger to cool the absorption solution in the absorber. The refrigeration system (COP) of the present invention is a cold source of the condenser, and the refrigeration coefficient (COP) is 3.0 or more. After the temperature of the absorption solution drops to -15 ° C and the sedimentation separation of the LiBr crystal is completed, the liquid feeding pump is started to send the supernatant in the absorber to the generator, and the LiBr concentration of the supernatant is -15 ° C. The saturated solubility is about 56%. The heat supply coefficient of this example is about 0.80. Comparative example

The existing absorption heat pump circulation system shown in Figure 1 is used for heating, and the wet steam with a saturation temperature of 75 °C is used as the driving heat source for the evaporator and the generator (ie, the external low-temperature heat source) at 15: °C. Cooling water acts as a source of cold to the condenser. The absorption solution uses water as the working medium, lithium bromide as the absorbent, the LiBr mass concentration of the absorption solution in the generator is 62%, and the LiBr mass concentration of the absorption solution in the absorber is 58%. Under this condition, the absorber absorbing heat release of 110 ° C, external working fluid from the suction _'; provided close to an external heat exchanger. The heat supply coefficient of this comparative example is about 0.47.

The heating coefficients of the above examples and comparative examples are defined as follows:

Heating coefficient = heat supplied to the outside through the absorption heat exchanger / (heat applied to the external low-temperature heat source + used to absorb the cooling required for solution regeneration)

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention. The skilled person can make some modifications or modifications to the equivalent embodiments by using the above-disclosed technical contents without departing from the technical scope of the present invention, but without departing from the technical solution of the present invention, according to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments are still within the scope of the technical solutions of the present invention. Industrial applicability

The absorption heating system of the present invention comprises: a generator in which a heat exchanger is generated, the hair The living device is filled with an absorbing solution; the absorber is provided with an absorption heat exchanger therein, the absorber is filled with an absorbing solution; a steam passage is connected to the generator and the absorber; and the absorption inside the generator The concentration of the solution absorbs the concentration of the solution in the absorber; and an absorption solution delivery device coupled to the generator and the absorber for transporting the absorption solution between the generator and the absorber. The low-concentration absorbing solution in the generator is heated by an external heat source to generate working fluid vapor, and the working fluid vapor is absorbed by the high-concentration absorbing solution in the absorber, and the absorbing heat is released at a high temperature, so that high-grade heat can be output. The heating system and the heating method of the present invention have the advantages of simple structure and high heat supply coefficient.

Claims

Rights request

An absorption heating system characterized in that it comprises:

a generator having a heat exchanger therein, the generator being filled with an absorption solution; an absorber having an absorption heat exchanger therein, the absorber being filled with an absorption solution; and a vapor passage connecting the a generator and the absorber;

Generator

2. An absorption heating system according to claim 1 further comprising an absorption solution delivery device coupled to said generator and said absorber for use between the generator and the absorber The absorption solution is delivered.

3. The absorption heating system according to claim 1, wherein said absorbing solution is composed of a working medium and an absorbent, and said working medium is one or more of water, methanol and ethanol. a mixture; the absorbent is one or a mixture of LiBr, LiCK LiNO ₃ , ZnCl ₂ and CaC.

4. An absorption heating system according to claim 1 wherein said absorber is placed inside the generator or a generator is placed inside said absorber.

5. The absorption heating system according to claim 1, wherein said generator and absorber have a common side wall, and said steam passage is a through hole formed in said side wall.

6. An absorption heating method, characterized in that it employs the absorption heating system of claim 1, the method comprising:

In the generator, heating the low concentration absorption solution and generating working fluid vapor;

The working fluid vapor is sent to the absorber through the steam passage, and the working fluid vapor is absorbed by the high concentration absorption solution in the absorber to release the high temperature absorption heat;

The heat exchange is performed in the absorber, and the above-mentioned absorption heat is output to the outside.

7. The absorption heating method according to claim 6, further comprising: stopping the heating generator when a difference between the concentration of the absorbing solution in the generator and the concentration of the absorbing solution in the absorber is less than a preset value Absorption solution in

Delivering the absorption solution in the generator to the absorber; Cooling the absorbing solution in the absorber to cause crystallization of the absorbent;

The supernatant of the absorber is delivered to the generator.

8. The absorption heating method according to claim 6, wherein the pressures in the generator and the absorber are the same.

The absorbing heat supply method according to claim 6, wherein the absorbing solution in the absorber is a saturated solution.