Refrigeration system

Abstract

The application discloses a refrigeration system, comprising: an absorber, a solution pump, a generator and a first heat exchanger which are sequentially connected, further comprising: an ejector connected with the first heat exchanger through an injection port, a second heat exchanger connected with the ejector through a being-injected port, a throttle valve connected with the second heat exchanger, a vapor-liquid separator connected with the throttle valve and the ejector outlet, and an outlet of the vapor-liquid separator connected with the absorber. By using the ejector to replace the throttle valve at the outlet side of the condenser, part of the expansion work can be recovered, the mechanical energy loss in the throttling process can be reduced, the driving force of the refrigerant into the absorber can be increased, and the absorption efficiency can be improved; meanwhile, the solution in the generator can be heated by using the heat pipe to recover the condensation heat, so that the cold and heat energy of the refrigeration system can be utilized to the maximum extent.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and in particular to a refrigeration system. Background Technology

[0002] With the advancement of technology, people increasingly aspire to a high-quality life, and air conditioning is playing an increasingly important role in people's lives. Currently, building energy consumption has become a major contributor, with the HVAC industry accounting for the majority of energy consumption. In the context of the era of "carbon peaking and carbon neutrality," the development of green and energy-saving products is urgently needed.

[0003] In traditional vapor compression refrigeration systems, expansion valves are used for throttling and pressure reduction, which results in mechanical energy loss of the high-pressure working fluid after throttling, affecting system performance. In absorption refrigeration systems, the generator requires an external heat source to provide heat to heat the solution, and the heat is dissipated at the system condenser, resulting in energy waste.

[0004] An absorption refrigeration system with heat recovery and an ejector is adopted. The ejector replaces the throttling valve to reduce throttling losses. At the same time, heat pipes are used to recover the condensation heat and heat the solution in the generator, which can maximize the utilization of the cold and heat energy of the refrigeration system. Summary of the Invention

[0005] In order to solve the technical problem of large throttling losses in the absorption refrigeration system using the throttling valve in the prior art, the present invention proposes a refrigeration system.

[0006] The technical solution adopted in this invention is:

[0007] The present invention proposes a refrigeration system comprising: an absorber, a solution pump, a generator, and a first heat exchanger connected in sequence; and further comprising: an ejector connected to the first heat exchanger via an ejector port; a second heat exchanger connected to the ejector port; a throttling valve connected to the second heat exchanger; and a vapor-liquid separator connected to the throttling valve and the ejector outlet, wherein the outlet of the vapor-liquid separator is connected to the absorber.

[0008] The present invention also includes a heat exchanger, wherein the evaporation end of the heat exchanger is disposed on the air outlet side of the first heat exchanger, and the condensation end of the heat exchanger is disposed inside the generator.

[0009] Preferably, the heat exchanger is a heat pipe.

[0010] The present invention also includes a bypass pipeline connecting the dilute solution outlet of the generator to the inlet of the absorber, wherein a second throttling valve is provided on the bypass pipeline.

[0011] Preferably, the ejector is an electric ejector.

[0012] Furthermore, the generator is heated by an external heat source.

[0013] Preferably, the external heat source is a solar heating source or an electric heating source.

[0014] The invention also includes: a controller and a second temperature sensor for detecting the temperature of the solution in the generator, the controller being used to adjust the opening degree of the external heat source and the operating frequency of the solution pump based on the deviation between the solution temperature detected by the second temperature sensor and the target temperature.

[0015] Furthermore, the fan corresponding to the first heat exchanger is a variable frequency fan.

[0016] The present invention also includes: a controller, a first temperature sensor and a pressure sensor disposed at the outlet end of the first heat exchanger, the controller being able to obtain the subcooling degree at the outlet of the first heat exchanger based on the temperature and pressure values ​​detected by the first temperature sensor and the pressure sensor, and adjust the operating frequency of the fan based on the deviation between the subcooling degree and the target subcooling degree.

[0017] Compared with the prior art, the present invention can recover part of the expansion energy by using an ejector instead of a throttling valve on the outlet side of the condenser, reducing the mechanical energy loss during the throttling process, and increasing the driving force for the refrigerant to enter the absorber, thereby improving the absorption efficiency; at the same time, the use of heat pipes to recover the condensation heat and heat the solution in the generator can maximize the utilization of the cold and heat energy of the refrigeration system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a structural diagram of an embodiment of the present invention;

[0020] Figure 2 This is a structural diagram of the ejector in an embodiment of the present invention;

[0021] Figure 3 This is a flowchart from an embodiment of the present invention;

[0022] 1. Solution pump; 2. Generator; 3. First heat exchanger; 4. Ejector; 5. Second heat exchanger; 6. Vapor-liquid separator; 7. First throttle valve; 8. Absorber; 9. Second throttle valve; 10. Heat pipe; 101. Evaporator end; 102. Condenser end; 11. External heat source; 12. Fan. Detailed Implementation

[0023] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0024] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] In traditional vapor compression refrigeration systems, expansion valves are used for throttling and pressure reduction, resulting in mechanical energy loss of the high-pressure working fluid after throttling, which affects system performance. In absorption refrigeration systems, the generator requires an external heat source to heat the solution, and heat is lost at the system condenser, resulting in energy waste. To address these issues, this invention proposes an absorption refrigeration system with heat recovery and an ejector. The ejector replaces the throttling valve, reducing throttling losses; simultaneously, heat pipes recover the condensate heat to heat the solution in the generator, maximizing the utilization of the refrigeration system's thermal energy.

[0026] like Figure 1 , 2 As shown, this invention proposes a refrigeration system, comprising: a solution pump 1, a generator 2, a first heat exchanger 3, an ejector 4, a second heat exchanger 5, a first throttling valve 7, a vapor-liquid separator 6, and an absorber 8. The power output side of the solution pump 1 is connected to the generator 2, and the outlet end of the generator 2 is connected to the first heat exchanger 3. The generator 2 is heated by an external heat source 11, which heats the solution input to the generator 2, turning it into a high-temperature, high-pressure vapor refrigerant that enters the first heat exchanger 3 for heat exchange. The first heat exchanger 3 is equipped with a fan 12 for driving air for heat exchange. The outlet end of the first heat exchanger 3 is connected to the ejector port a of the ejector 4, and the ejector outlet c of the ejector 4 is connected to the inlet of the vapor-liquid separator 6. The liquid outlet of the vapor-liquid separator 6 is connected to the first throttling valve 7, which is connected to the second heat exchanger 5. The second heat exchanger 5 is connected to the ejected port b of the ejector 4. The gas outlet of the vapor-liquid separator 6 is then connected to the absorber 8 to form a cycle.

[0027] The high-temperature, high-pressure refrigerant generated in generator 2 enters the first heat exchanger 3 for condensation and heat dissipation. The cooled, low-temperature, high-pressure refrigerant enters the ejector port of ejector 4, ejecting the refrigerant from the second heat exchanger 5. After the two refrigerants are mixed in the mixing chamber of ejector 4, they enter the diffuser chamber for pressurization and then enter the vapor-liquid separator 6 through the outlet of ejector 4. This can reduce the mechanical energy loss during the throttling process and increase the driving force for the refrigerant to enter the absorber 8, thereby improving the absorption efficiency.

[0028] In a specific embodiment, a heat exchanger is also included. Specifically, a heat pipe 10 can be selected as the heat exchanger. The evaporation end 101 of the heat exchanger is located on the air outlet side of the first heat exchanger 3, and the condensation end 102 of the heat exchanger is located inside the generator 2. The heat of the first heat exchanger 3 can be recovered to the generator 2 to heat the solution, so as to maximize the utilization of the cold and hot energy of the refrigeration system.

[0029] In a specific embodiment, a bypass pipeline is also included, connecting the dilute solution outlet of generator 2 to the inlet of absorber 8. A second throttle valve 9 is provided on the bypass pipeline. The solution in absorber 8 enters generator 2 via solution pump 1. After the solution in generator 2 is heated, the generated vapor refrigerant enters the condenser. The dilute solution with a relatively low concentration returns to absorber 8 through the second throttle valve 9.

[0030] In a specific embodiment, the first throttle valve 7 is an electronic expansion valve, the first heat exchanger is a condenser, and the second heat exchanger is an evaporator.

[0031] In a specific embodiment, the ejector 4 is an electric ejector 4, wherein the nozzle throat is equipped with a spray needle, which can adjust the depth of the spray needle into the nozzle throat and thus adjust the effective flow cross-sectional area of ​​the nozzle throat (i.e., the throat cross-sectional area) to achieve the purpose of adjusting the ejection ratio (ejection ratio = ejected flow rate / main ejection flow rate).

[0032] The generator 2 is heated by an external heat source 11. The external heat source 11 can be an electric heating source, such as heating by an electric heating wire, or a solar heat source or other heating sources, all of which are within the protection scope of this invention.

[0033] like Figure 3As shown, the present invention further includes a controller (it should be noted that the controller controlling the operating frequency of the fan, the opening degree of the external heat source, and the frequency of the solution pump can be the same controller or multiple controllers controlling them separately), and a first temperature sensor and a pressure sensor installed at the outlet of the first heat exchanger 3 for detecting the state of the refrigerant at the outlet; a second temperature sensor is installed inside the generator 2 for detecting the solution temperature inside the generator 2. The controller can detect the refrigerant subcooling at the outlet of the first heat exchanger through the first temperature sensor and the pressure sensor (subcooling = saturation temperature corresponding to saturation pressure - measured refrigerant temperature; the specific methods for detecting and calculating subcooling are common in the prior art and can be fully implemented, so they will not be described in detail), compare it with the target subcooling, and adjust the operating frequency of the fan of the first heat exchanger according to the comparison result. When the measured subcooling is greater than the target subcooling plus the subcooling deviation, the fan operating frequency decreases; when the target subcooling minus the subcooling deviation is less than the measured subcooling and less than the target subcooling plus the subcooling deviation, the fan maintains its current operating frequency; when the measured subcooling is less than the target subcooling minus the subcooling deviation, the fan operating frequency increases. The subcooling deviation can be set according to needs and actual conditions.

[0034] Specifically, the generator is equipped with a second temperature sensor to detect the solution temperature. The controller compares the solution temperature with the target temperature and adjusts the heating output of the external heat source based on the comparison result. Specifically, when the measured solution temperature > target temperature + temperature deviation, the external heat source opening is reduced (specifically, the power is decreased), while the operating frequency of the solution pump is increased; when the measured target temperature - temperature deviation ≤ solution temperature ≤ target temperature + temperature deviation, the external heat source maintains its current opening level, and the solution pump maintains its current operating frequency; when the measured solution temperature < target temperature - temperature deviation, the external heat source opening is increased, while the operating frequency of the solution pump is decreased. The temperature deviation value can be set according to needs or actual conditions. Furthermore, the heat of the solution in the generator already includes the condensation heat delivered by the heat pipe.

[0035] The specific operating principle is as follows:

[0036] The high-temperature and high-pressure refrigerant generated in generator 2 enters the condenser for condensation and heat dissipation. The cooled low-temperature and high-pressure refrigerant enters the ejector port a of ejector 4 to eject the refrigerant from the evaporator. After the two refrigerants are mixed in the mixing chamber of ejector 4, they enter the diffuser chamber for pressurization and then enter the vapor-liquid separator 6 through the ejector outlet c of ejector 4.

[0037] In the vapor-liquid separator 6, the liquid refrigerant is throttled by the electronic expansion valve 7 and then enters the evaporator to evaporate and absorb heat, producing a cooling effect. After evaporation and heat absorption in the evaporator, the refrigerant enters the ejector 4 through the ejector port b and mixes with the refrigerant from the ejector port a. The gaseous refrigerant in the vapor-liquid separator 6 enters the absorber 8 and is absorbed by the dilute solution.

[0038] The solution in absorber 8 enters generator 2 via solution pump 1. After the solution in generator 2 is heated, the generated vapor refrigerant enters condenser. The relatively low concentration dilute solution enters absorber 8 via second throttle valve 9.

[0039] This system is equipped with a heat pipe 10, one end of which is the evaporation end 101, located on the air outlet side of the condenser; the other end of the heat pipe 10 is the condensation end 102, located inside the generator 2; the condensation heat generated at the condenser is transferred to the generator 2 through the heat pipe 10 for heating the solution.

[0040] It should be noted that the terminology used above is for describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, 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.

[0041] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0042] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0043] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0044] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A refrigeration system, comprising: An absorber, a solution pump, a generator, and a first heat exchanger connected in sequence are characterized in that they further include: an ejector whose ejector port is connected to the first heat exchanger; a second heat exchanger connected to the ejector port of the ejector; a throttling valve connected to the second heat exchanger; and a vapor-liquid separator connected to the throttling valve and the outlet of the ejector, wherein the outlet of the vapor-liquid separator is connected to the absorber. It also includes a heat exchanger, the evaporation end of which is located on the air outlet side of the first heat exchanger, and the condensation end of which is located inside the generator. The heat exchanger is a heat pipe. The generator is heated by an external heat source.

2. The refrigeration system as described in claim 1, characterized in that, It also includes a bypass line connecting the dilute solution outlet of the generator to the inlet of the absorber, and the bypass line is equipped with a second throttle valve.

3. The refrigeration system as described in claim 1, characterized in that, The ejector is an electric ejector.

4. The refrigeration system as described in claim 1, characterized in that, The external heat source is a solar heating source or an electric heating source.

5. The refrigeration system as described in claim 1, characterized in that, Also includes: The controller includes a controller and a second temperature sensor that detects the temperature of the solution in the generator. The controller adjusts the opening of the external heat source and the operating frequency of the solution pump based on the deviation between the solution temperature detected by the second temperature sensor and the target temperature.

6. The refrigeration system as described in claim 1, characterized in that, The fan corresponding to the first heat exchanger is a variable frequency fan.

7. The refrigeration system as described in claim 6, characterized in that, Also includes: The controller includes a first temperature sensor and a pressure sensor installed at the outlet of the first heat exchanger. The controller obtains the subcooling at the outlet of the first heat exchanger based on the temperature and pressure values ​​detected by the first temperature sensor and the pressure sensor, and adjusts the operating frequency of the fan based on the deviation between the subcooling and the target subcooling.

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