Solar refrigeration system adopting micro-gap partition plate heat exchanger

Abstract

The invention relates to the technical field of refrigeration combination systems, discloses a solar refrigeration system adopting a micro-gap partition plate heat exchanger, and solves the problems that in a conventional generator, an absorbent dilute solution which is circularly injected can reduce the temperature of an absorbent in the generator, so that the overall temperature of the generator is reduced, and the refrigerant steam generation efficiency is influenced. The absorbent flowing upwards through the first channel is gradually preheated by the side surface of the heat exchange plate and is heated by the highest temperature of the heat exchange plate at the top of the heat exchange plate, so that the absorbent above the heat exchange plate is always heated by the highest temperature of the top of the heat exchange plate, and the absorbent at the position keeps the maximum efficiency to evaporate water vapor; and under the condition that the temperature of the hydrothermal medium is limited, the efficiency of forming refrigerant steam by water in the evaporation absorbent is greatly improved, and the thermal conversion efficiency of the solar refrigeration system is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration combined systems, and particularly to a solar refrigeration system using a micro-gap partition heat exchanger. Background Art

[0002] Solar refrigeration systems are often applied to buildings and places with sufficient area, using an array of solar collectors in cooperation with a heat exchanger using water as a heat carrier to generate a water heat medium, and then cooperating with an absorption refrigeration machine to provide a cold source or a heat source for the facility site.

[0003] Among them, in the absorption refrigeration machine, the absorbent (commonly lithium bromide solution) in the generator exchanges heat with the water heat medium to heat the absorbent, separate the water in it to generate refrigerant vapor, and at the same time further concentrate the absorbent into a concentrated solution. The concentrated solution then enters the absorber to be diluted into a dilute solution, and then circulates back to the generator to form a closed loop; The heat exchange components of the generator are commonly plate type and tube type, and their heat exchange principles are roughly the same, that is, the absorbent and the water heat medium flow in separated channels to implement heat exchange. Since the evaporation efficiency of water in the absorbent in the generator is positively correlated with the temperature, but the dilute solution of the absorbent injected cyclically will mix into the original temperature of the absorbent in the generator, resulting in a certain decrease in the overall temperature of the absorbent in the generator and maintaining within this range, thereby affecting the generation efficiency of the refrigerant vapor. Therefore, how to further improve the heat exchange efficiency inside the generator under the limited water heat medium temperature conditions, so as to significantly enhance the generation efficiency of the refrigerant vapor, has extremely important guiding value for the design and optimization of the solar refrigeration system. Summary of the Invention

[0004] The purpose of the present invention is to provide a solar refrigeration system using a micro-gap partition heat exchanger to solve the problem that in a conventional generator, the dilute solution of the absorbent injected cyclically will reduce the temperature of the absorbent in the generator, resulting in a decrease in its overall temperature and affecting the generation efficiency of the refrigerant vapor.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A solar refrigeration system using a micro-gap partition heat exchanger, including an absorption refrigeration machine, a heat preservation water tank, a water heat exchanger body, and a solar collector array. A generator mechanism is provided inside the absorption refrigeration machine, and the generator mechanism includes: A box body, a liquid supply tank for the absorbent to pass through is provided on the lower side of the box body, and a water heat medium interface A for the water heat medium to pass through is provided on the upper side; The heat exchange plates are assembled on the inner side of the box body and are arranged in a parallel array. There are multiple heat exchange plates, and a first channel for the absorbent to flow upward is provided between two adjacent heat exchange plates. A second channel for the water heat medium to flow downward is provided inside the box body, so that the surface temperature of the heat exchange plates decreases in a downward gradient. The absorbent flowing upward through the first channel is gradually preheated by the side surfaces of the heat exchange plates and is heated at the top of the heat exchange plates at the highest temperature, so that the water contained in the absorbent is evaporated.

[0006] As a further description of the above technical solution: The heat exchange plate includes two symmetrical partition plates, and the surfaces of the partition plates are stamped with protrusions toward one side. The protrusions on one side of the two partition plates are in close contact to form an S-shaped second channel.

[0007] As a further description of the above technical solution: Flat plates are hermetically arranged on the upper and lower sides of the two partition plates respectively, and the left and right sides are hermetically connected to the inner wall of the box body.

[0008] As a further description of the above technical solution: For the array of heat exchange plates, turning liquid plates are provided at the upper ends of the two heat exchange plates close to the outside.

[0009] As a further description of the above technical solution: Parallel heat-resistant films are provided on the upper side of the turning liquid plates through support frames. Small holes for steam to pass through are provided on the surfaces of the heat-resistant films, and the turning liquid plates slide on the side surfaces of the heat exchange plates.

[0010] As a further description of the above technical solution: Limit blocks for limiting the maximum descending height of the turning liquid plates are provided on the side surfaces of the heat exchange plates.

[0011] As a further description of the above technical solution: The outermost heat exchange plate and the inner wall of the box body adjacent to it form a reflux channel for the concentrated absorbent solution. A liquid return tank for concentrating the absorbent solution in the reflux channel is provided at the lower side of the box body.

[0012] As a further description of the above technical solution: The lower side of the reflux channel is spaced from the channel for upward liquid supply of the liquid supply tank by a copper plate.

[0013] As a further description of the above technical solution: A flow equalizing assembly for making the incoming absorbent flow in a flat manner is provided between the liquid supply tank and the heat exchange plates. The flow equalizing assembly includes a plurality of flow equalizing plates adapted to the channel width between the liquid supply tank and the heat exchange plates.

[0014] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: The absorbent flowing upward through the first channel is gradually preheated by the side of the heat exchange plate and heated by the highest temperature of the heat exchange plate at the top of the heat exchange plate, so that the absorbent above the heat exchange plate is continuously heated by the highest temperature at the top of the heat exchange plate, enabling the absorbent at this position to maintain the maximum efficiency in evaporating water vapor. Under the condition of limited temperature of the water heat medium, the efficiency of evaporating the water in the absorbent to form refrigerant vapor is greatly improved, further enhancing the heat conversion efficiency of the solar refrigeration system. Among them, when the heat supply of the water heat medium is unstable, through the cooperation of the heat-resistant film and the liquid-turning plate, the evaporation amount of the vapor can be adaptively adjusted. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the system of the present invention; Figure 2 is a schematic plan view of the absorption chiller of the present invention; Figure 3 is a schematic structural diagram of the generator mechanism of the present invention; Figure 4 is a schematic diagram of the internal structure of the generator mechanism of the present invention; Figure 5 is a schematic diagram of the absorbent flow path in the generator mechanism of the present invention; Figure 6 is a schematic diagram of the structure on one side below the generator mechanism of the present invention; Figure 7 is a schematic diagram of the structure on the other side below the generator mechanism of the present invention; Figure 8 is a schematic diagram of the water heat medium interface A and the docking groove of the present invention; Figure 9 is a schematic diagram of the heat exchange plate of the present invention.

[0016] In the figure: 10, absorption chiller; 20, insulation water tank; 30, water heat exchanger body; 40, solar collector array; 50, generator mechanism; 51, box body; 52, water heat medium interface A; 521, docking groove; 53, liquid return groove; 531, interface B; 54, liquid supply groove; 541, interface C; 55, heat exchange plate; 551, isolation plate; 552, protrusion; 553, flat plate; 56, liquid-turning plate; 561, limit block; 57, heat-resistant film; 58, advection component; 581, advection plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] To further understand the content of the present invention, the present invention will be described in detail with reference to the accompanying drawings.

[0019] Combined with Figures 1 - 9 , a solar refrigeration system using a micro-gap partition heat exchanger includes an absorption chiller 10, a heat preservation water tank 20, a water heat exchanger body 30, and a solar collector array 40. A generator mechanism 50 is provided in the absorption chiller 10. The water heat exchanger body 30 exchanges heat between the heat energy converted from solar energy by the solar collector array 40 and water, so that the water has a high temperature. The hot water is stored in the heat preservation water tank 20 and participates in heat exchange with the absorbent in the generator mechanism 50 as a heat medium (hereinafter referred to as water heat medium). For example Figure 2 , the absorbent in the heat exchange evaporates into vapor, and the vapor participates in the subsequent working process of the absorption chiller 10 as refrigerant vapor; usually, the temperature of the water heat medium stored in the heat preservation water tank 20 is limited. Therefore, when the temperature of the water heat medium is limited, it is particularly necessary to increase the temperature at which the absorbent in the generator mechanism 50 is heated, so as to increase the generation efficiency of the refrigerant vapor and further improve the working efficiency of the absorption chiller 10. Therefore, in order to improve the generation efficiency of the refrigerant vapor in the absorption chiller 10, the generator mechanism 50 proposed by the present invention includes: A box body 51, a liquid supply tank 54 for the absorbent to enter is provided on the lower side of the box body 51, and a water heat medium interface A52 for the water heat medium to enter is provided on the upper side. The heat exchange plate 55, preferably made of copper, is assembled inside the box body 51 and arranged in a parallel array with multiple ones. There is a first channel for the absorbent to flow upward between two adjacent heat exchange plates 55. A second channel for the water heat medium to flow downward is provided inside the box body 51, so that the surface temperature of the heat exchange plate 55 shows a downward gradient decrease. When the water heat medium just enters the heat exchange plate 55, it has the highest temperature. As it flows in the heat exchange plate 55 and participates in heat exchange, the temperature gradually decreases. Therefore, the surface temperature of the heat exchange plate 55 gradually decreases from top to bottom. The top of the heat exchange plate 55 is heated by the newly introduced water heat medium to the highest temperature; while the absorbent flowing upward through the first channel is first gradually preheated by the side of the heat exchange plate 55, so that the temperature gradually increases. After flowing to the top of the heat exchange plate 55, it is heated to the highest temperature to participate in the process of evaporating water vapor; it can be further understood that: the top of the heat exchange plate 55 is an evaporation section for heating the absorbent to evaporate the refrigerant vapor, and the side of the heat exchange plate 55 is a preheating section for preheating the absorbent. For the absorbent flowing in the generator mechanism 50, the absorbent in the evaporation section is maintained at the highest temperature by the top of the heat exchange plate 55 and also maintains the highest temperature to evaporate the refrigerant vapor. However, the newly flowing-in and lower-temperature absorbent at the bottom of the generator mechanism 50 is first preheated in the preheating section to avoid directly injecting it into the evaporation section, which may cause a decrease in the overall temperature of the absorbent in the evaporation section; referring to Figure 2 , compared with the existing generator mechanism 50, directly heating the absorbent in the cavity through a heat exchange component is equivalent to only having an evaporation section. The circulating and lower-temperature absorbent is directly injected into the evaporation section, which will reduce the temperature of the absorbent in the cavity to a certain extent, resulting in a certain decrease in the overall temperature of the absorbent in the cavity, and further affecting the evaporation efficiency of the refrigerant vapor. In this embodiment, by using the temperature change of the water heat medium flowing in the heat exchange plate 55 and the reverse flow process of the absorbent, the top of the heat exchange plate 55 with the highest temperature is used for the formation of the refrigerant vapor evaporation, and the side part is used for preheating the upward-supplied absorbent, so that the absorbent at the top of the heat exchange plate 55 maintains the highest temperature to evaporate and form the refrigerant vapor; Since the absorbent above the heat exchange plate 55 is always heated by the highest temperature at the top of the heat exchange plate 55, the absorbent at this position maintains the maximum efficiency to evaporate water vapor, so that under the condition of limited water heat medium temperature, the efficiency of evaporating the water in the absorbent to form the refrigerant vapor is greatly improved, and the heat conversion efficiency of the solar refrigeration system is further improved.

[0020] Combined with Figure 9 , the heat exchange plate 55 includes two symmetrical partition plates 551. Protrusions 552 extending to one side are stamped on the surface of the partition plates 551. The protrusions 552 on one side of the two partition plates 551 are closely abutted to form an S-shaped second channel; On the upper and lower sides of the two partition plates 551, flat plates 553 are hermetically arranged respectively, and are hermetically connected to the inner wall of the box body 51 on the left and right sides. The water-heat medium interface A52 for supplying the water-heat medium is correspondingly connected to the plurality of heat exchange plates 55 through a plurality of docking grooves 521 arranged on the inner side, so that the water-heat medium is introduced from the upper side of the S-shaped second channel and flows out from the lower side, as shown by the arrows in the figure, and is docked by another water-heat medium interface A52 on one side of the box body 51, so that the heat-exchanged water-heat medium flows out. By cooperating with the heat preservation water tank 20, the water-heat medium forms a closed loop in the heat exchange plates 55. The newly introduced water-heat medium has the highest temperature, so that the upper side of the partition plate 551 and the flat plate 553 are heated by the limited-temperature water-heat medium to the highest temperature that can be reached. At the same time, the absorbent flowing upward through the first channel and gradually preheated will not cause the temperature of the absorbent on the upper layer of the flat plate 553 to drop sharply. Therefore, the flat plate 553 at the highest temperature and the upper side of the partition plate 551 continuously heat the preheated absorbent, so that the absorbent on the upper layer of the flat plate 553 maintains the maximum efficiency to evaporate water vapor.

[0021] Combined with Figures 4 - 5 , in the heat exchange plates 55 of the array, for the two heat exchange plates 55 close to the outside, turning plates 56 are provided at the upper outer ends thereof. Through the turning plates 56, the absorbent above the heat exchange plates 55 is stored and maintained at a certain liquid level height. The absorbent is circularly injected into the bottom of the generator mechanism 50, and the absorbent overflowing the turning plates 56 above is used as the concentrated absorbent solution for reflux.

[0022] On the upper side of the liquid turning plate 56, a parallel heat-resistant film 57 is provided through a support frame. Small holes for steam to pass through are formed on the surface of the heat-resistant film 57. The liquid turning plate 56 slides on the side of the heat exchange plate 55. According to the cubic amount of water vapor evaporated by the absorbent above the heat exchange plate 55 per unit time, the heat-resistant film 57 can be pushed to a certain height. Correspondingly, the position of the liquid turning plate 56 fixedly connected to the support frame and the heat-resistant film 57 will also rise. The rising liquid turning plate 56 will further cause the liquid level of the absorbent stored in the evaporation area above the heat exchange plate 55 to rise. When the heating condition at the top of the heat exchange plate 55 is fixed, the increase in the liquid amount of the absorbent in the evaporation area will lead to a decrease in the steam evaporation amount. Similarly, when the evaporation amount of the absorbent evaporating steam decreases, the thrust of the steam on the heat-resistant film 57 will also be insufficient, which will further cause the height of the liquid turning plate 56 to drop, thereby reducing the liquid level of the absorbent above the heat exchange plate 55 and decreasing the storage amount of the absorbent in the evaporation area. As the liquid level of the absorbent decreases, the heating efficiency of the top of the heat exchange plate 55 on it will increase, thereby increasing the evaporation amount of the rising steam. In the above dynamic adjustment, the heat-resistant film 57 adaptively maintains at a suitable height to stabilize the steam generation amount, make the fluctuation range of the steam generation amount small, and improve the refrigeration stability (i.e., constant temperature) of the absorption refrigerator 10; when the water heat medium heating is unstable (here referring to a long time span, such as morning, noon, and evening in a day, and temperature changes caused by weather changes), through the cooperation of the heat-resistant film 57 and the liquid turning plate 56, the liquid storage height of the absorbent in the evaporation area is automatically adjusted, thereby adaptively adjusting the steam evaporation amount to meet the constant temperature refrigeration of the absorption refrigerator 10.

[0023] A limit block 561 for restricting the maximum descending height of the liquid turning plate 56 is provided on the side of the heat exchange plate 55 to avoid the occurrence of dry burning caused by too low liquid level of the absorbent above the heat exchange plate 55.

[0024] Combined with Figures 4 - 6 As shown, the outermost heat exchange plate 55 and the inner wall of the box body 51 adjacent to it form a reflux channel for the concentrated absorbent solution. A liquid return tank 53 for concentrating the concentrated absorbent solution in the reflux channel is provided at the lower side of the box body 51. The dilute absorbent solution is injected through the interface C541 on one side of the liquid supply tank 54, and then discharged through the interface B531 connected to one side of the liquid return tank 53, forming a closed loop through the absorber inside the absorption refrigerator 10.

[0025] The lower side of the reflux channel and the upward liquid supply channel of the liquid supply tank 54 are separated by a copper plate. The refluxed concentrated absorbent solution has a relatively high temperature. Using it to perform preliminary heat exchange with the dilute absorbent solution on one side through the copper plate can realize the heat energy recovery of the concentrated absorbent solution and reduce the heat source consumption.

[0026] Combined with Figure 6As shown, a horizontal flow component 58 for horizontally flowing the introduced absorbent is provided between the liquid supply tank 54 and the heat exchange plate 55. The horizontal flow component 58 includes a plurality of horizontal flow plates 581 adapted to the channel width between the liquid supply tank 54 and the heat exchange plate 55. Through the plurality of horizontal flow plates 581, the absorbent entering through the liquid supply tank 54 enters the first channel in a horizontal flow manner so as to be uniformly heated.

[0027] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A solar refrigeration system using a micro-gap partition heat exchanger, comprising an absorption chiller (10), a heat preservation water tank (20), a water heat exchanger body (30) and a solar collector array (40), wherein a generator mechanism (50) is arranged in the absorption chiller (10), and is characterized in that: The generator mechanism (50) includes: A box body (51), with a liquid supply tank (54) for the absorbent to pass through provided on the lower side of the box body (51), and a water heat medium interface A (52) for the water heat medium to pass through provided on the upper side; Heat exchange plates (55), assembled inside the box body (51), arranged in a parallel array with multiple ones. A first channel for the absorbent to flow upward is provided between two adjacent heat exchange plates (55). A second channel for the water heat medium to flow downward from top to bottom is provided inside the box body (51), so that the surface temperature of the heat exchange plates (55) decreases in a downward gradient. The absorbent flowing upward through the first channel is gradually preheated by the side surfaces of the heat exchange plates (55) and is heated at the highest temperature at the top of the heat exchange plates (55), so that the water contained in the absorbent is evaporated.

2. The solar refrigeration system using a micro-gap partition heat exchanger according to claim 1, wherein: The heat exchange plate (55) includes two symmetrical partition plates (551). Protrusions (552) extending to one side are stamped on the surfaces of the partition plates (551). The protrusions (552) on one side of the two partition plates (551) are in close contact with each other to form an S-shaped second channel.

3. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 2, characterized in that: Flat plates (553) are hermetically arranged on the upper and lower sides of the two partition plates (551) respectively, and are hermetically connected to the inner wall of the box body (51) on the left and right sides.

4. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 1, characterized in that: Among the array of heat exchange plates (55), turning plates (56) are provided at the upper outer ends of the two heat exchange plates (55) close to the outside.

5. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 4, characterized in that: A parallel heat-resistant film (57) is provided on the upper side of the turning plate (56) through a support frame. Small holes for the steam to pass through are provided on the surface of the heat-resistant film (57). The turning plate (56) slides on the side surface of the heat exchange plate (55).

6. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 5, characterized in that: A limit block (561) for restricting the maximum descending height of the turning plate (56) is provided on the side surface of the heat exchange plate (55).

7. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 1, characterized in that: The outermost heat exchange plate (55) and the inner wall adjacent to the box body (51) form a reflux channel for the concentrated absorbent solution. A liquid return tank (53) for concentrating the absorbent solution in the reflux channel is provided on the lower side of the box body (51).

8. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 7, characterized in that: The lower side of the reflux channel is spaced from the channel for upward liquid supply of the liquid supply tank (54) by a copper plate.

9. A solar refrigeration system using a micro-gap partition heat exchanger according to claim 5, characterized in that: A flow equalizing assembly (58) for making the incoming absorbent flow in a uniform manner is provided between the liquid supply tank (54) and the heat exchange plate (55). The flow equalizing assembly (58) includes a plurality of flow equalizing plates (581) adapted to the channel width between the liquid supply tank (54) and the heat exchange plate (55).

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