A new type of high-efficiency absorption heat pump

Abstract

The present invention discloses a novel and efficient absorption heat pump, comprising: a steam compressor, a primary generator, an absorber, a solution pump, a throttling device, an evaporator, a condenser, a solution heat exchanger, a secondary generator, an ejector and a refrigerant pump; the primary generator, the secondary generator, the condenser, the evaporator and the absorber adopt shell-and-tube heat exchangers; the primary generator is connected to the steam compressor, the steam compressor is connected to the secondary generator, the secondary generator is connected to the ejector, and the ejector is connected to the condenser; the condenser is connected to the evaporator via the throttling device, the absorber is connected to the condenser, the absorber is connected to the solution heat exchanger via the solution pump, and the solution heat exchanger is respectively connected to the primary generator and the secondary generator; a refrigerant pump is connected between the top and the bottom of the evaporator. The present invention has a higher coefficient of performance (COP) value for heating and a temperature of the produced hot water, and solves the problem of the limitation of the temperature grade of the low-temperature heat source on the temperature grade of the produced hot water.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and particularly to a novel and efficient absorption heat pump. Background Art

[0002] As a new energy device, absorption heat pumps are widely used in various industries, with significant energy-saving and carbon-reduction benefits. Among them, the lithium bromide absorption heat pump is the most common and widely used type of absorption heat pump. This kind of heat pump usually uses gas, steam, high-temperature hot water or flue gas as the driving energy, recovers the waste heat in the low-temperature waste heat of 20°C to 40°C, and produces hot water with a temperature about 40°C higher than the low-temperature heat source. The highest hot water outlet temperature is about 85°C, which is supplied to heat users, thus achieving an energy utilization target with a heating coefficient of about 1.7 to 2.3.

[0003] During the application process of the lithium bromide absorption heat pump, the temperature of the produced hot water is greatly restricted by the grade of the low-temperature waste heat source. When the grade of the low-temperature waste heat is low and the heat demand grade of the heat user is high, it is very difficult to meet the actual on-site requirements. At the same time, under the background of the dual-carbon policy, in order to increase its heating coefficient, the lithium bromide absorption heat pump usually sets up high- and low-pressure two-stage generators, and the maximum COP value can only reach 2.3. Moreover, the equipment cost increases significantly. At the same time, the temperature of the produced hot water is also strictly restricted by the operating parameters of the low-pressure generator. Usually, the produced hot water temperature does not exceed 75°C, and the technical bottleneck is prominent. Therefore, it is necessary to propose a novel and efficient absorption heat pump to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a novel and efficient absorption heat pump for the deficiencies of the existing technology, so as to solve the problems of the restriction of the temperature grade of the low-temperature heat source on the temperature grade of the produced hot water and the problem that the temperature of the produced water needs to be improved in the existing absorption heat pump.

[0005] The present invention provides a novel and efficient absorption heat pump, including: a steam compressor, a primary generator, an absorber, a solution pump, a throttling device, an evaporator, a condenser, a solution heat exchanger, a secondary generator, an ejector, and a refrigerant pump; the primary generator, secondary generator, condenser, evaporator, and absorber all adopt shell-and-tube heat exchangers; the primary generator is connected to the steam compressor, the steam compressor is connected to the secondary generator, the secondary generator is connected to the ejector, and the ejector is connected to the condenser; the condenser is connected to the evaporator via the throttling device, the absorber is located on one side of the evaporator and is connected to the condenser, the absorber is connected to the solution heat exchanger via the solution pump, and the solution heat exchanger is respectively connected to the primary generator and the secondary generator; a refrigerant pump is connected between the top and bottom of the evaporator.

[0006] Further, the condenser is provided with a high-temperature hot water outlet.

[0007] Further, the primary generator is provided with a driving heat source inlet and a driving heat source outlet.

[0008] Further, the evaporator is provided with a low-temperature heat source inlet and a low-temperature heat source outlet.

[0009] Further, the absorber is provided with a low-temperature hot water inlet.

[0010] Further, a demisting device is arranged at the steam outlet of the primary generator.

[0011] Further, an automatic pressure regulating device is arranged at the outlet of the ejector.

[0012] The present invention has the following beneficial effects: A novel and efficient absorption heat pump provided by the present invention has a higher coefficient of performance (COP) value of heating and a higher temperature of the produced hot water compared with a conventional absorption heat pump; it solves the problem of the limitation of the temperature grade of the low-temperature heat source on the temperature grade of the produced hot water; it has a broader space in waste heat utilization; it can effectively integrate green power consumption and waste heat utilization to improve the energy utilization efficiency; and it significantly reduces the processing costs of the generator and the condenser. Description of the Drawings

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0014] Figure 1 It is a schematic diagram of the novel and efficient absorption heat pump of the present invention.

[0015] Illustration: 1 - steam compressor; 2 - primary generator; 3 - driving heat source inlet; 4 - driving heat source outlet; 5 - absorber; 6 - solution pump; 7 - low-temperature hot water inlet; 8 - throttling device; 9 - evaporator; 10 - low-temperature heat source inlet; 11 - low-temperature heat source outlet; 12 - high-temperature hot water outlet; 13 - condenser; 14 - solution heat exchanger; 15 - secondary generator; 16 - ejector; 17 - refrigerant pump. Detailed Embodiments

[0016] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be pointed out that the following detailed description is exemplary and is intended to provide further illustration of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0017] For ease of description, spatial relative terms such as "above", "over", "on the upper surface of", "upper" etc. may be used herein to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, the device described as "above" or "over" other devices or structures will then be positioned "below" or "beneath" the other devices or structures. Thus, the exemplary term "above" can include both the orientation of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations), and the corresponding explanations for the spatial relative descriptions used herein will be made accordingly.

[0018] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the present application is thorough and complete, and the concept of these exemplary embodiments is fully conveyed to those of ordinary skill in the art. In the drawings, for clarity, the thickness of layers and regions is enlarged, and the same reference numerals are used to denote the same devices, and thus their descriptions will be omitted.

[0019] Please refer to Figure 1 , an embodiment of the present invention provides a novel and efficient absorption heat pump, including: a steam compressor 1, a primary generator 2, an absorber 5, a solution pump 6, a throttling device 8, an evaporator 9, a condenser 13, a solution heat exchanger 14, a secondary generator 15, an ejector 16, a refrigerant pump 17 and a supporting pipeline system; wherein, the primary generator 2, the secondary generator 15, the condenser 13, the evaporator 9 and the absorber 5 all adopt shell-and-tube heat exchangers.

[0020] Specifically, the primary generator 2 is connected to the steam compressor 1. The steam compressor 1 is connected to the pipeline inside the secondary generator 15. The pipeline inside the secondary generator 15 is connected to the ejector 16. The secondary generator 15 is also connected to the ejector 16. The ejector 16 is connected to the condenser 13. The condenser 13 is connected to the evaporator 9 via the throttling device 8. The absorber 5 is located on one side of the evaporator 9 and the pipeline inside the absorber 5 is connected to the pipeline inside the condenser 13. The absorber 5 is connected to the solution heat exchanger 14 via the solution pump 6. The solution heat exchanger 14 is respectively connected to the primary generator 2 and the secondary generator 15. A refrigerant pump 17 is connected between the top and the bottom of the evaporator 9. The condenser 13 is provided with a high-temperature hot water outlet 12. The primary generator 2 is provided with a driving heat source inlet 3 and a driving heat source outlet 4. The evaporator 9 is provided with a low-temperature heat source inlet 10 and a low-temperature heat source outlet 11. The absorber 5 is provided with a low-temperature hot water inlet 7. A demisting device is arranged at the steam outlet of the primary generator 2 to prevent liquid refrigerant from entering the steam compressor. An automatic pressure regulating device is arranged at the outlet of the ejector 16 to ensure the operating pressures required by the condenser and the evaporator.

[0021] For the novel and efficient absorption heat pump provided by the embodiment of the present invention, the operation mode from the condenser 13 to the primary generator 2 is the same as that of the conventional absorption heat pump. In order to further improve the heating coefficient - COP value of the heat pump and at the same time increase the temperature of the hot water produced by the heat pump, the process of the conventional double-effect absorption heat pump is optimized and designed in the present invention. A steam compressor 1 is innovatively introduced between the primary generator 2 and the secondary generator 15. The refrigerant steam from the primary generator 2 enters the steam compressor 1. The steam compressor 1 compresses and does work on the refrigerant steam. After the refrigerant steam is heated and pressurized, it is discharged into the secondary generator 15 to be used as its driving heat source, thereby increasing the gas discharge amount and the steam temperature grade of the secondary generator 15, and thus realizing the preliminary improvement of the COP value of the heat pump and the temperature of the produced hot water.

[0022] Meanwhile, the steam serving as the driving heat source of the secondary generator 15 releases heat, cools down and condenses into high-pressure liquid refrigerant. In order to utilize the pressure energy of this part of the high-pressure liquid refrigerant, an ejector 16 is arranged between the secondary generator 15 and the condenser 13. The high-pressure liquid refrigerant is used as the ejecting medium and injected into the ejector 16 to eject the refrigerant steam evaporated by the secondary generator 15. This not only recovers the pressure energy of the high-pressure liquid refrigerant, but also further reduces the evaporation pressure of the secondary generator 15, increases the gas discharge amount of the secondary generator 15. At the same time, after the high-pressure liquid refrigerant and the steam produced by the secondary generator are mixed in the ejector 16, the steam temperature at the outlet of the ejector 16 will further increase.

[0023] In addition, during the transition from high pressure to low pressure, part of the liquid refrigerant flashes into steam, increasing the total amount of steam entering the condenser 13. As a result, the coefficient of performance (COP) of the heat pump and the temperature of the produced hot water are significantly improved. Since the steam discharged from the ejector 16 to the condenser 13 is in a saturated steam state, the overall heat transfer coefficient of the condenser 13 is increased, thereby reducing the heat exchange area and equipment cost of the condenser 13. Finally, by adding a steam compressor 1 and an ejector 16, the goal of improving the COP of the absorption heat pump and the temperature of the produced hot water is comprehensively achieved, while reducing the equipment costs of the generator and the condenser to a certain extent.

[0024] In summary, the present invention introduces a steam compressor between the high-pressure generator and the low-pressure generator. The refrigerant steam from the high-pressure generator is compressed, and its temperature and pressure continue to rise to parameters that meet the requirements of heat users. Then, it is discharged from the outlet of the steam compressor to the low-pressure generator and used as the driving energy of the low-pressure generator. The high-pressure refrigerant steam cools and condenses into high-pressure refrigerant water in the low-pressure generator. The high-pressure refrigerant water enters the ejector as an ejecting medium to eject the low-pressure refrigerant steam generated by the low-pressure generator. The two are mixed and then enter the condenser to complete the preparation of hot water required by heat users. On the one hand, the pressure energy of the high-pressure refrigerant water is recycled, the operating pressure of the low-pressure generator is reduced, the gas discharge volume of the low-pressure generator is increased, and thus the COP value of the heat pump is increased. On the other hand, the temperature of the refrigerant steam at the outlet of the low-pressure generator is increased, thereby increasing the temperature of the hot water produced by the heat pump. In addition, the original high-pressure generator and low-pressure generator can both be designed as low-pressure generators, which not only expands the temperature grade range of the driving heat source but also reduces the equipment configuration requirements. Finally, the mutual restriction problem between the COP value of the conventional absorption heat pump and the temperature of the produced hot water is solved, and the application field and scope of the heat pump are expanded.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] It should be noted that the terms "first", "second", etc. in the specification, claims, and above-mentioned drawings of the present application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0027] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A novel and efficient absorption heat pump, characterized in that, Including: A steam compressor (1), a primary generator (2), an absorber (5), a solution pump (6), a throttling device (8), an evaporator (9), a condenser (13), a solution heat exchanger (14), a secondary generator (15), an ejector (16), and a refrigerant pump (17); the primary generator (2), the secondary generator (15), the condenser (13), the evaporator (9), and the absorber (5) are all shell-and-tube heat exchangers; The primary generator (2) is connected to the steam compressor (1), the steam compressor (1) is connected to the secondary generator (15), the secondary generator (15) is connected to the ejector (16), and the ejector (16) is connected to the condenser (13); The condenser (13) is connected to the evaporator (9) via the throttling device (8), the absorber (5) is located on one side of the evaporator (9) and is connected to the condenser (13), the absorber (5) is connected to the solution heat exchanger (14) via the solution pump (6), and the solution heat exchanger (14) is respectively connected to the primary generator (2) and the secondary generator (15); a refrigerant pump (17) is connected between the top and the bottom of the evaporator (9).

2. The novel and highly efficient absorption heat pump according to claim 1, wherein, The condenser (13) is provided with a high-temperature hot water outlet (12).

3. The novel and highly efficient absorption heat pump according to claim 1, characterized in that, The primary generator (2) is provided with a driving heat source inlet (3) and a driving heat source outlet (4).

4. The novel and highly efficient absorption heat pump according to claim 1, characterized in that The evaporator (9) is provided with a low-temperature heat source inlet (10) and a low-temperature heat source outlet (11).

5. A novel and efficient absorption heat pump according to claim 1, characterized in that, The absorber (5) is provided with a low-temperature hot water inlet (7).

6. The novel and highly efficient absorption heat pump according to claim 1, wherein A demisting device is arranged at the steam outlet of the primary generator (2).

7. A novel and highly efficient absorption heat pump according to claim 1, characterized in that, An automatic pressure regulating device is arranged at the outlet of the ejector (16).

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