Refrigerating system and air conditioner

Abstract

The invention provides a refrigerating system and an air conditioner, the refrigerating system comprises a first compressor, a first heat exchanger, a first valve, a second heat exchanger and an ejector, the first compressor, the first heat exchanger, the first valve and the second heat exchanger are connected to form at least partial structure of a first refrigerating loop; the ejector comprises a first inlet end, a second inlet end and a first outlet end, the first inlet end is communicated to the outlet end of the second heat exchanger, the second inlet end is communicated to the exhaust end of the first compressor, and the first outlet end of the ejector is communicated to the inlet end of the second heat exchanger. According to the invention, the evaporation or condensation heat exchange efficiency can be improved, so that a refrigerant which does not fully exchange heat can continuously participate in heat exchange circulation, and the compressor is prevented from sucking air and carrying liquid; the problem that in a heat exchanger of a refrigerating system in the prior art, heat exchange of refrigerants is not sufficient, and consequently the refrigerants are not completely evaporated or condensed is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and more specifically to a refrigeration system and an air conditioner. Background Technology

[0002] Cascade refrigeration systems can significantly broaden the range of cooling or heating, enabling tiered utilization of heat and cold. By combining different working fluids in the high-temperature and low-temperature sections, they can fully leverage the performance advantages of each temperature range to achieve energy savings and meet the needs of special applications. They are widely used in low-temperature refrigeration and high-temperature heat pump fields. In a cascade system, the condenser-evaporator is the core heat exchange module connecting the high-temperature and low-temperature sections; it serves as both the condenser in the low-temperature section and the evaporator in the high-temperature section.

[0003] For shell-and-tube heat exchangers with in-tube evaporation, to fully utilize the heat exchange area and maximize the heat exchange capacity of the arranged tube bundle, the vapor and liquid phases should be evenly distributed into each heat exchange tube as much as possible. Therefore, the liquid homogenization structure at the tube inlet is crucial to its heat exchange performance. If the liquid inlet is uneven, some heat exchange tubes will have too much liquid inside and cannot evaporate completely, resulting in liquid carryover in the outlet gas and low superheat of the compressor suction gas; while some heat exchange tubes will have very low flow and will easily evaporate dry, resulting in underutilization of the heat exchange area and poor overall performance of the heat exchanger.

[0004] Because existing refrigeration systems suffer from insufficient heat exchange of the refrigerant, resulting in incomplete evaporation or condensation of the refrigerant, this invention researches and designs a refrigeration system and an air conditioner. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of insufficient heat exchange of refrigerant in the heat exchanger of the refrigeration system in the prior art, which leads to incomplete evaporation or condensation of refrigerant, thereby providing a refrigeration system and an air conditioner.

[0006] To address the above problems, the present invention provides a refrigeration system comprising: The first compressor, the first heat exchanger, the first valve, the second heat exchanger, and the ejector are connected to form at least a portion of a first refrigeration circuit. The ejector includes a first inlet end, a second inlet end, and a first outlet end. The first inlet end is connected to the outlet end of the second heat exchanger, the second inlet end is connected to the exhaust end of the first compressor, and the first outlet end of the ejector is connected to the inlet end of the second heat exchanger.

[0007] In some implementations... It also includes a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, a fifth pipeline, and a sixth pipeline. The first pipeline is connected between the outlet of the first compressor and the inlet of the first heat exchanger. The second pipeline is connected between the outlet of the first heat exchanger and the first inlet of the second heat exchanger. The first valve is disposed on the second pipeline. The third pipeline is connected between the first outlet of the second heat exchanger and the inlet of the first compressor. One end of the fourth pipeline is connected to the outlet end of the second heat exchanger, and the other end is connected to the first inlet end of the ejector. One end of the fifth pipeline is connected to the exhaust end of the first compressor, and the other end is connected to the second inlet end of the ejector. One end of the sixth pipeline is connected to the inlet end of the second heat exchanger, and the other end is connected to the first outlet end of the ejector.

[0008] In some implementations... The first valve is a throttling device capable of adjusting its opening. A second valve is installed on the third pipeline, a third valve is installed on the fifth pipeline, and a fourth valve is installed on the fourth pipeline. The second, third, and fourth valves are all control valves capable of controlling the opening and closing of the pipelines. When the operating load of the refrigeration system is less than a preset value, the fourth valve can be controlled to close and the third valve can be controlled to open. When the operating load of the refrigeration system is greater than or equal to the preset value, both the fourth and third valves can be controlled to open.

[0009] In some implementations... It also includes a second compressor, a third heat exchanger, a sixth valve, and a seventh, eighth, and ninth pipeline. One end of the seventh pipeline is connected to the outlet of the second compressor, and the other end is connected to the second inlet of the second heat exchanger. One end of the eighth pipeline is connected to the inlet of the second compressor, and the other end is connected to the refrigerant outlet of the third heat exchanger. One end of the ninth pipeline is connected to the second outlet of the second heat exchanger, and the other end is connected to the refrigerant inlet of the third heat exchanger. The sixth valve is located on the eighth pipeline and can regulate the refrigerant flow rate. A fifth valve is also located on the ninth pipeline.

[0010] In some implementations... The second heat exchanger includes a shell, one end of which has a first liquid storage chamber, a flow equalization plate, and a tube sheet. The first liquid storage chamber has a tube-side inlet and a return port. The tube-side inlet is the first inlet and is connected to the outlet end of the second pipeline. The return port is connected to the outlet end of the sixth pipeline. The first liquid storage chamber forms the liquid inlet chamber of the second heat exchanger. Multiple heat exchange tubes are arranged inside the shell. The flow equalization plate is located between the first liquid storage chamber and the tube sheet, so that the first liquid storage chamber is connected to the tube sheet through the flow equalization plate. The tube sheet is connected to the multiple heat exchange tubes.

[0011] In some implementations... The flow equalization plate is provided with a plurality of flow equalization holes. One end of each flow equalization hole is connected to the heat exchange tube through the tube sheet, and the other end of each flow equalization hole is connected to the first liquid storage chamber. The plurality of flow equalization holes are divided into multiple rows along the vertical direction. In two adjacent rows of flow equalization holes in the vertical direction, the total flow area of ​​the flow equalization holes in the upper row is greater than that in the lower row, and the diameter of the flow equalization holes in the upper row is greater than that in the lower row.

[0012] In some implementations... Along the vertical direction from top to bottom, the total flow area of ​​each row of flow equalization holes gradually decreases, and the diameter of each row of flow equalization holes gradually decreases from top to bottom.

[0013] In some implementations... The other end of the shell is connected to a flange, and a second liquid storage chamber is formed inside the flange. The second liquid storage chamber is connected to the outlet end of the shell. The end of the flange away from the shell is also connected to a cylinder. The cylinder is provided with a tube-side air outlet and a tube-side liquid outlet. The tube-side air outlet is the first outlet. The tube-side air outlet is connected to the inlet end of the third pipeline. The tube-side liquid outlet is connected to the inlet end of the fourth pipeline.

[0014] In some implementations... The cylinder is equipped with a first baffle plate inside, and a filter element is connected to the lower end of the first baffle plate. The air outlet of the tube is opposite to the first baffle plate in the height direction, so that the fluid from the shell is blocked and separated by the first baffle plate, and then discharged through the air outlet of the tube after passing through the filter element.

[0015] In some implementations... The cylinder is also provided with a second baffle plate. The second baffle plate extends horizontally to form a horizontal baffle plate and is connected to the filter element. At the same time, the second baffle plate is connected to the horizontal inner wall of the cylinder. The first baffle plate extends vertically to form a vertical baffle plate and the upper end of the first baffle plate extends to connect with the top inner wall of the cylinder.

[0016] In some implementations... A liquid baffle is also provided inside the cylinder. At least a portion of the structure of the liquid baffle is located above the liquid outlet of the tube and below the first air baffle. The liquid baffle is also provided with a flow hole so that the liquid blocked and separated by the liquid baffle can be guided to the liquid outlet of the tube.

[0017] In some implementations... The liquid baffle includes a horizontal liquid baffle and a vertical liquid baffle. The horizontal liquid baffle extends horizontally and is located above the liquid outlet of the tube and below the first air baffle. The vertical liquid baffle extends vertically and its upper end is connected to the horizontal liquid baffle. Its lower end is connected to the bottom inner wall of the cylinder. The flow hole is formed on the vertical liquid baffle in a direction that penetrates both of its end faces.

[0018] The present invention also provides an air conditioner that includes the aforementioned refrigeration system.

[0019] The refrigeration system and air conditioner provided by this invention have the following beneficial effects: 1. This invention employs an ejector structure in the refrigeration system, specifically, the first inlet end of the ejector is connected to the outlet end of the second heat exchanger, the second inlet end of the ejector is connected to the exhaust end of the first compressor, and the first outlet end of the ejector is connected to the inlet end of the second heat exchanger. This allows the refrigerant fluid (especially liquid) at the outlet end of the second heat exchanger to be ejected back to the inlet end of the second heat exchanger using the airflow velocity and pressure of the first compressor exhaust. This ensures that any liquid that has not completely evaporated into gas in the second heat exchanger can be ejected back to the inlet and re-enter the second heat exchanger for evaporation and heat absorption. This ensures sufficient heat exchange for the refrigerant in the second heat exchanger, guaranteeing adequate heat exchange (evaporation or condensation), improving the efficiency of evaporation or condensation, and ensuring complete evaporation or condensation. It also allows any refrigerant that has not undergone sufficient heat exchange to continue participating in the heat exchange cycle, preventing liquid carryover during compressor intake. This effectively solves the problem of insufficient refrigerant heat exchange in existing refrigeration systems, leading to incomplete evaporation or condensation of the refrigerant.

[0020] 2. The present invention further provides effective control over these two pipelines by installing a third valve on the pipeline connecting the compressor exhaust and the second inlet of the ejector, and a fourth valve on the pipeline connecting the outlet of the second heat exchanger and the first inlet of the ejector. Specifically, when the operating load of the refrigeration system is less than a preset value (low load condition), the fourth valve can be controlled to close, and the third valve can be controlled to open. When the operating load of the refrigeration system is greater than or equal to the preset value (normal load condition), both the fourth and third valves can be controlled to open. Under low load conditions, the ejector pipeline at the heat exchanger outlet can be closed, and only the pipeline connecting the compressor exhaust to the ejector can be opened, serving only as a bypass for the refrigerant. This allows the ejector structure to switch to bypass mode via valve control. Under low load conditions, the exhaust is bypassed to the inlet, increasing the inlet dryness and gas velocity of the heat exchanger tubes, effectively solving the problem of uneven liquid inlet flow caused by low inlet flow. Under normal operating conditions, the third and fourth valves are opened, utilizing the compressor exhaust to eject the refrigerant from the heat exchanger outlet back to the inlet, improving heat exchange efficiency.

[0021] 3. The present invention further improves the heat exchanger by setting the flow equalization holes on the flow equalization plate at the inlet end of the heat exchanger to have a larger diameter at the top and a smaller diameter at the bottom. This is because during the condensation process of the refrigerant from top to bottom, the liquid film becomes thicker and thicker on the outer wall of the tube from top to bottom. Therefore, the heat exchange performance at the top is better than that at the bottom. Thus, the present invention designs the upper hole diameter to be larger, which can maximize the heat exchange efficiency of the heat exchanger. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the refrigeration system of the present invention; Figure 2 This is a schematic diagram of the structure of the second heat exchanger in the refrigeration system of the present invention; Figure 3 yes Figure 2 Exploded view of the first liquid storage chamber, tube sheet and flow equalization plate in the middle; Figure 4 yes Figure 3 A front view of the flow equalization plate in the structure; Figure 5 yes Figure 2 A three-dimensional structural diagram of the flange and cylinder on the right side of the shell; Figure 6 yes Figure 5 A front longitudinal section diagram; Figure 7 yes Figure 6 Structural diagram of the vertical air baffle; Figure 8 yes Figure 6 Structural diagram of the horizontal air baffle; Figure 9 yes Figure 6 A structural diagram of the filter screen; Figure 10 yes Figure 6 The structural diagram of the liquid baffle.

[0023] The reference numerals in the attached figures are as follows: 1. First compressor; 2. First heat exchanger; 21. Cooling water outlet; 22. Cooling water inlet; 3. First valve; 4. Second heat exchanger; 40. Shell; 41. First inlet; 42. First outlet; 43. Second inlet; 44. Second outlet; 45. First liquid storage chamber; 46. Flow equalization plate; 47. Tube sheet; 48. Heat exchange tube; 49. Flow equalization orifice; 410. Return port; 411. Flange; 412. Second liquid storage chamber; 413. Shell; 414. First baffle plate; 415. Filter element; 416. Tube-side liquid outlet; 417. Second baffle plate; 418. Liquid baffle plate; 419. Flow hole; 420. Horizontal baffle plate Liquid plate; 421, vertical baffle plate; 5, ejector; 51, first inlet end; 52, second inlet end; 53, first outlet end; 6, second valve; 7, third valve; 8, fourth valve; 9, second compressor; 10, third heat exchanger; 10a, refrigerant outlet; 10b, refrigerant inlet; 10c, refrigerant outlet; 10d, refrigerant inlet; 11, sixth valve; 12, fifth valve; 101, first pipeline; 102, second pipeline; 103, third pipeline; 104, fourth pipeline; 105, fifth pipeline; 106, sixth pipeline; 107, seventh pipeline; 108, eighth pipeline; 109, ninth pipeline. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] like Figure 1-10As shown, the present invention provides a refrigeration system comprising: A first compressor 1, a first heat exchanger 2, a first valve 3, a second heat exchanger 4, and an ejector 5 are connected to form at least a portion of a first refrigeration circuit. The ejector 5 includes a first inlet end 51, a second inlet end 52, and a first outlet end 53. The first inlet end 51 is connected to the outlet end of the second heat exchanger 4, the second inlet end 52 is connected to the exhaust end of the first compressor 1, and the first outlet end 53 of the ejector 5 is connected to the inlet end of the second heat exchanger 4.

[0031] This invention, through the aforementioned structure of an ejector in the refrigeration system, particularly with the first inlet end of the ejector connected to the outlet end of the second heat exchanger, the second inlet end connected to the exhaust end of the first compressor, and the first outlet end connected to the inlet end of the second heat exchanger, utilizes the airflow velocity and pressure of the first compressor exhaust to eject the refrigerant fluid (especially liquid) at the outlet end of the second heat exchanger back to the inlet end of the second heat exchanger. This allows liquid that has not completely evaporated into gas in the second heat exchanger to be ejected back to the inlet and re-enter the second heat exchanger for evaporation and heat absorption. This ensures sufficient heat exchange for the refrigerant in the second heat exchanger, guaranteeing adequate heat exchange (evaporation or condensation), improving the efficiency of evaporation or condensation heat exchange, ensuring complete evaporation or condensation, and allowing refrigerant that has not undergone sufficient heat exchange to continue participating in the heat exchange cycle, preventing liquid carryover during compressor intake. This effectively solves the problem of insufficient refrigerant heat exchange in existing refrigeration systems, leading to incomplete evaporation or condensation of the refrigerant.

[0032] In some implementations... It also includes a first pipe 101, a second pipe 102, a third pipe 103, a fourth pipe 104, a fifth pipe 105, and a sixth pipe 106. The first pipe 101 is connected between the outlet of the first compressor 1 and the inlet of the first heat exchanger 2. The second pipe 102 is connected between the outlet of the first heat exchanger 2 and the first inlet 41 of the second heat exchanger 4. The first valve 3 is disposed on the second pipe 102. The third pipe 103 is connected between the first outlet 42 of the second heat exchanger 4 and the inlet of the first compressor 1. One end of the fourth pipe 104 is connected to the outlet end of the second heat exchanger 4, and the other end is connected to the first inlet end 51 of the ejector 5. One end of the fifth pipe 105 is connected to the exhaust end of the first compressor 1, and the other end is connected to the second inlet end 52 of the ejector 5. One end of the sixth pipe 106 is connected to the inlet end of the second heat exchanger 4, and the other end is connected to the first outlet end 53 of the ejector 5.

[0033] This is a further preferred structural form and connection method of the refrigeration system of the present invention, which can ensure that the two input ends and one output end of the ejector are connected to the outlet end of the second heat exchanger, the discharge end of the compressor and the inlet end of the second heat exchanger respectively. Thus, by using the ejection method, the separated liquid refrigerant is guided back to the inlet end, further improving the heat exchange efficiency and avoiding a large amount of liquid refrigerant from entering the compressor.

[0034] In some implementations... The first valve 3 is a throttling device capable of adjusting its opening. The third pipeline 103 is equipped with a second valve 6, the fifth pipeline 105 is equipped with a third valve 7, and the fourth pipeline 104 is equipped with a fourth valve 8. The second valve 6, the third valve 7, and the fourth valve 8 are all control valves capable of controlling the opening and closing of the pipelines. When the operating load of the refrigeration system is less than a preset value, the fourth valve 8 can be controlled to close and the third valve 7 can be controlled to open. When the operating load of the refrigeration system is greater than or equal to the preset value, both the fourth valve 8 and the third valve 7 can be controlled to open.

[0035] This invention further enables effective control of these two pipelines by installing a third valve on the pipeline connecting the compressor exhaust and the second inlet of the ejector, and a fourth valve on the pipeline connecting the outlet of the second heat exchanger and the first inlet of the ejector. Specifically, when the operating load of the refrigeration system is less than a preset value (low load condition), the fourth valve can be controlled to close, and the third valve can be controlled to open. When the operating load of the refrigeration system is greater than or equal to the preset value (normal load condition), both the fourth and third valves can be controlled to open. Under low load conditions, the ejector pipeline at the heat exchanger outlet can be closed, and only the pipeline connecting the compressor exhaust to the ejector can be opened, serving only as a bypass for refrigerant. This allows the ejector structure to switch to bypass mode via valve control. Under low load conditions, the exhaust is bypassed to the inlet, increasing the inlet dryness and gas velocity of the heat exchanger tubes, effectively solving the problem of uneven liquid inlet flow caused by low inlet flow. Under normal operating conditions, the third and fourth valves are opened, utilizing the compressor exhaust to eject the refrigerant from the heat exchanger outlet back to the inlet, improving heat exchange efficiency.

[0036] In the ejector return mode of this invention, the liquid working medium A separated by the gas-liquid separation structure of the right water chamber (second liquid storage chamber 412) accumulates in the liquid storage tank at the bottom of the right water chamber. After a certain liquid level is formed in the tank, the liquid working medium is ejected to the tube-side return port 410 of the left water chamber by the ejector connected to the tube-side liquid outlet 416. The high-pressure gas source of the ejector is compressor exhaust. The ejector is not always open. When the operating conditions are stable and the suction temperature, suction superheat or exhaust superheat decreases, it is determined that there is liquid (when the liquid storage tank is full, its liquid level is higher than the baffle plate 418, at this time a large amount of liquid working medium will be carried away by the suction). The third valve 7 and the fourth valve 8 of the pipeline are opened to start the ejector return, and the liquid working medium separated from the right water chamber is ejected to the inlet end of the left water chamber (tube-side return port 410) to participate in tube-side distribution and heat exchange.

[0037] In the bypass gas replenishment mode of this invention, when the unit is operating at low load or the operating conditions change, the system circulation volume decreases or the throttling dryness decreases, resulting in a significant reduction in the inlet gas flow rate, which deviates severely from the design range of the flow equalization plate. This leads to uneven liquid distribution, excessive refrigerant distribution in some pipes that cannot be completely evaporated, severe liquid carryover at the outlet, and low superheat in the suction / discharge. At this time, only the third valve 7 is opened to activate the bypass mode, leading part of the compressor exhaust to the left water chamber inlet (pipe-side liquid return port 410), increasing the gas flow rate in the left water chamber, improving the mixing uniformity and flow equalization effect, avoiding a large amount of liquid carryover at the outlet, and ensuring stable operation of the unit.

[0038] In some implementations... It also includes a second compressor 9, a third heat exchanger 10, a sixth valve 11, a seventh pipeline 107, an eighth pipeline 108, and a ninth pipeline 109. One end of the seventh pipeline 107 is connected to the outlet end of the second compressor 9, and the other end is connected to the second inlet 43 of the second heat exchanger 4. One end of the eighth pipeline 108 is connected to the inlet end of the second compressor 9, and the other end is connected to the refrigerant outlet 10a of the third heat exchanger 10. One end of the ninth pipeline 109 is connected to the second outlet 44 of the second heat exchanger 4, and the other end is connected to the refrigerant inlet 10b of the third heat exchanger 10. The sixth valve 11 is installed on the eighth pipeline 108 and can regulate the refrigerant flow. A fifth valve 12 is also installed on the ninth pipeline 109.

[0039] This is a further preferred structural form of the refrigeration system of the present invention. Through the second compressor, the third heat exchanger and other structures and pipelines, a refrigeration cycle system that overlaps with the first cycle loop is formed. The two refrigeration cycle systems overlap at the second heat exchanger. The second refrigeration system has a condenser structure at the second heat exchanger, and the first refrigeration system has an evaporator structure at the second heat exchanger. In the overlapping refrigeration cycle system, the refrigerant at the outlet of the second heat exchanger can be guided back to the inlet of the second heat exchanger, thereby improving the efficiency of its evaporation or condensation heat exchange and making the heat exchange sufficient.

[0040] like Figure 1 As shown, the cascade system of the present invention consists of a high-temperature stage, a low-temperature stage, and an intermediate heat exchange module, wherein the intermediate heat exchange module (condenser-evaporator) is both the evaporator of the high-temperature stage and the condenser of the low-temperature stage.

[0041] System working principle: In the high-temperature stage system cycle, the liquid working fluid A condensed from the high-temperature stage condenser flows out of the condenser through the refrigerant outlet. After being throttled by the throttling valve (first valve 3), the low-temperature and low-pressure gas-liquid two-phase working fluid A enters the tube side of the heat exchange tube bundle inside the condenser-evaporator through the tube side inlet (first inlet 41) and exchanges heat with the high-temperature working fluid B on the shell side of the condenser-evaporator. After absorbing heat, the liquid working fluid A evaporates into a gaseous state and flows out through the tube side outlet (first outlet 42) into the suction port of the high-pressure stage compressor. The low-pressure gaseous working fluid A is compressed into a high-pressure and high-temperature gaseous state by the compressor and enters the condenser shell side through the refrigerant inlet on the shell side of the condenser, where it exchanges heat with the tube side cooling water. The high-temperature gaseous working fluid A on the shell side is condensed into a liquid state by the tube side cooling water and flows out through the refrigerant outlet to continue participating in the high-temperature stage system cycle.

[0042] In the low-temperature stage system cycle, the liquid working fluid B condensed on the shell side of the intermediate heat exchange module condenser-evaporator flows out through refrigerant outlet 10a. After being throttled by the throttling valve (fifth valve 12), the low-temperature, low-pressure gas-liquid two-phase working fluid B enters the shell side of the evaporator through the refrigerant inlet 10b and exchanges heat with the refrigerant in the tube side of the evaporator. After absorbing heat, the liquid working fluid B evaporates into a gaseous state and flows out through the refrigerant outlet 10a on the shell side, entering the suction port of the low-pressure stage compressor. The low-pressure gaseous working fluid B is compressed by the compressor into a high-pressure, high-temperature gaseous state, and enters the shell side of the condenser-evaporator through the refrigerant inlet (second inlet 43) on the shell side of the condenser-evaporator, where it exchanges heat with the refrigerant A in the tube side. The high-temperature gaseous working fluid B in the shell side is condensed into a liquid state by the low-temperature working fluid A in the tube side and flows out through the refrigerant outlet (second outlet 44) to continue participating in the low-temperature stage system cycle.

[0043] In some implementations... The second heat exchanger 4 includes a shell 40. One end of the shell 40 has a first liquid storage chamber 45, a flow equalization plate 46, and a tube sheet 47. The first liquid storage chamber 45 has a tube-side inlet and a return port 410. The tube-side inlet is the first inlet 41, which is connected to the outlet end of the second pipeline 102. The return port 410 is connected to the outlet end of the sixth pipeline 106. The first liquid storage chamber 45 forms the liquid inlet chamber of the second heat exchanger 4. A plurality of heat exchange tubes 48 are arranged inside the shell 40. The flow equalization plate 46 is located between the first liquid storage chamber 45 and the tube sheet 47, so that the first liquid storage chamber 45 is connected to the tube sheet 47 through the flow equalization plate 46. The tube sheet 47 is connected to the plurality of heat exchange tubes 48.

[0044] This is a preferred structural form of the second heat exchanger of the present invention, wherein one end of the shell is a first liquid storage chamber and a flow equalization plate, the first inlet of the second heat exchanger is connected to the first liquid storage chamber, and after stabilization in the chamber, the flow is equalized through the flow equalization plate, and the refrigerant is conducted through the holes on the tube sheet to multiple heat exchange tubes to effectively exchange heat with the heat exchange fluid in the shell.

[0045] In some implementations... The flow equalization plate 46 is provided with a plurality of flow equalization holes 49. One end of each flow equalization hole 49 is connected to the heat exchange tube 48 through the tube sheet 47, and the other end of each flow equalization hole 49 is connected to the first liquid storage chamber 45. The plurality of flow equalization holes 49 are divided into multiple rows along the vertical direction. In two adjacent rows of flow equalization holes in the vertical direction, the total flow area of ​​the flow equalization holes in the upper row is greater than that in the lower row, and the diameter of the flow equalization holes in the upper row is greater than that in the lower row.

[0046] The present invention further describes the design of the flow equalization holes on the flow equalization plate at the inlet end of the heat exchanger, which have a larger diameter at the top and a smaller diameter at the bottom. This is because during the condensation process of the refrigerant from top to bottom, the liquid film becomes thicker and thicker on the outer wall of the tube from top to bottom. Therefore, the heat exchange performance at the top is better than that at the bottom. Thus, the present invention designs the upper hole diameter to maximize the heat exchange efficiency of the heat exchanger.

[0047] In some implementations... Along the vertical direction from top to bottom, the total flow area of ​​each row of flow equalization holes gradually decreases, and the diameter of each row of flow equalization holes gradually decreases from top to bottom.

[0048] The flow equalization plate of the present invention is further preferably configured such that the aperture gradually decreases from top to bottom, which can further match the thickness of the liquid film from top to bottom, thereby further improving the heat exchange performance at the upper end, reducing the distribution of refrigerant flow at the lower end, improving the overall heat exchange performance, and avoiding unnecessary flow distribution to the lower end that would lead to a decrease in heat exchange performance.

[0049] The intermediate heat exchange module of this invention uses a shell-side condenser for working fluid B and a tube-side evaporator for working fluid A, serving as both an evaporator for the high-temperature stage working fluid A and a condenser for the low-temperature stage working fluid B. Combined with... Figure 2 The condenser-evaporator consists of left and right water chambers, left and right tube sheets, a shell, supports, and heat exchange tube bundles. The shell has a shell-side inlet (second inlet 43) and a shell-side outlet (second outlet 44). The left water chamber (first liquid storage chamber 45) has a tube-side inlet (first inlet 41) and a return liquid port 410. The right water chamber has a tube-side gas outlet (first outlet 42) and a tube-side liquid outlet 416. Combined with... Figure 3 , Figure 4 A flow equalization plate 46 is provided in the left water chamber of the tube side inlet of the condenser evaporator and on the outside of the left tube sheet. A flow equalization hole (flow equalization hole 49) is opened on it. The position of the hole corresponds one-to-one with the heat exchange tube opening on the tube sheet, so as to evenly distribute the working fluid A at the tube side inlet into the heat exchange tube as needed.

[0050] Because the working fluid B condenses on the shell side, the amount of condensate gradually increases from top to bottom of the shell-side tube bank, meaning the liquid film on the heat exchange tube surface gradually thickens. This causes the condensation heat transfer to gradually decrease from top to bottom. Similarly, the evaporation heat transfer inside the tubes also varies depending on the tube bank, meaning the required liquid refrigerant flow rate is inconsistent for different tube banks. Therefore, the inlet flow distribution plate of the tube side is partitioned with openings, such as... Figure 3 As shown, the tube bundle is divided into upper, middle and lower sections. The diameter of the flow equalization orifice in the upper section is larger than that in the middle section and larger than that in the lower section. This is because the liquid film in the bottom tube bundle is thicker and may even be soaked in condensate, resulting in a smaller heat exchange in the bottom tube bundle. Therefore, its opening is the smallest.

[0051] In some implementations... The other end of the housing 40 is connected to a flange 411, and a second liquid storage chamber 412 is formed inside the flange 411. The second liquid storage chamber 412 is connected to the outlet end of the housing 40. The end of the flange 411 away from the housing 40 is also connected to a cylinder 413. The cylinder 413 is provided with a tube-side air outlet and a tube-side liquid outlet 416. The tube-side air outlet is the first outlet 42. The tube-side air outlet is connected to the inlet end of the third pipeline 103. The tube-side liquid outlet 416 is connected to the inlet end of the fourth pipeline 104.

[0052] This is a further preferred structural form of the second heat exchanger of the present invention, namely, a second liquid storage chamber is set at its right end as the outlet end, which can store the refrigerant after heat exchange with the shell in the second liquid storage chamber. The gas is discharged through the gas outlet of the tube side on the cylinder, and the liquid can be injected into the ejector through the liquid outlet of the tube side by the fourth pipeline, and further returned to the inlet end of the second heat exchanger. This allows the liquid refrigerant that has not been sufficiently heat-exchanged to be guided back to the inlet end for further heat exchange, continue to participate in the heat exchange cycle, improve the degree of heat exchange, and improve the heat exchange efficiency.

[0053] In some implementations... The cylinder 413 is provided with a first baffle plate 414 inside. A filter element 415 is connected to the lower end of the first baffle plate 414, and the tube outlet is opposite to the first baffle plate 414 in the height direction, so that the fluid from the shell 40 is blocked and separated by the first baffle plate 414, and then discharged through the tube outlet after passing through the filter element 415.

[0054] The present invention can block the fluid after heat exchange in the shell by means of the first baffle plate, preventing the gas containing liquid from being discharged directly from the tube outlet. The first baffle plate can block and separate the gas and liquid, and further filter impurities and remove liquid by the filter element, ensuring that the gas discharged from the tube outlet is of high purity, and further ensuring that the compressor does not suck in liquid.

[0055] In some implementations... The interior of the cylinder 413 is also provided with a second baffle plate 417. The second baffle plate 417 extends horizontally to form a horizontal baffle plate and is connected to the filter element 415. At the same time, the second baffle plate 417 is connected to the inner wall of the horizontal side of the cylinder 413. The first baffle plate 414 extends vertically to form a vertical baffle plate and the upper end of the first baffle plate 414 extends to connect with the top inner wall of the cylinder 413.

[0056] The present invention also features a second baffle plate that extends horizontally and connects to the filter element to support it. This baffle plate also acts as a barrier to prevent the fluid from flowing upwards, further improving the gas-liquid separation effect and ensuring that the compressor does not draw in liquid.

[0057] In some implementations... Inside the cylinder 413, a liquid baffle 418 is also provided. At least a portion of the structure of the liquid baffle 418 is located above the tube outlet 416 and below the first air baffle 414. The liquid baffle 418 is also provided with a flow hole 419 so that the liquid blocked and separated by the liquid baffle 418 can be guided to the tube outlet 416.

[0058] The present invention also uses the baffle structure provided above the liquid outlet of the tube to block the fluid, preventing it from entering the liquid outlet of the tube from top to bottom and being discharged. This prevents the liquid mixed with gas from being discharged directly from the liquid outlet of the tube, and can play a further role in gas-liquid separation. The further separated liquid is discharged from the flow hole to the liquid outlet of the tube, while the gas is discharged upward from the gas outlet of the tube, further improving the gas-liquid separation effect.

[0059] In some implementations... The liquid baffle 418 includes a horizontal liquid baffle 420 and a vertical liquid baffle 421. The horizontal liquid baffle 420 extends horizontally and is located above the liquid outlet 416 of the tube and below the first air baffle 414. The vertical liquid baffle 421 extends vertically and its upper end is connected to the horizontal liquid baffle 420. The lower end of the vertical liquid baffle 421 is connected to the bottom inner wall of the cylinder 413. The flow hole 419 is formed on the vertical liquid baffle 421 in a direction that penetrates both of its end faces.

[0060] This is a further preferred structural form of the baffle plate of the present invention, namely, it includes two baffle plates in the horizontal and vertical directions. The horizontal baffle plate mainly blocks the fluid flowing down from the first baffle plate, preventing the liquid mixed with gas from being directly discharged from the tube outlet. The vertical baffle plate can further separate the liquid separated by the horizontal baffle plate, and a flow hole is opened on the vertical baffle plate to guide the separated liquid to the tube outlet, thereby further improving the gas-liquid separation effect.

[0061] The right water chamber (second liquid storage chamber 412) of the tube outlet of the present invention is provided with a gas-liquid separation structure (including a vertical first baffle plate 414, a horizontal second baffle plate 417, a filter screen (filter element 415) and a liquid return structure (liquid baffle plate 418, tube outlet 416) to separate the liquid refrigerant entrained in the outlet gaseous working fluid, prevent the compressor from sucking in liquid, and store and draw out the separated liquid working fluid.

[0062] The gas-liquid two-phase working fluid A, entering through the left water chamber inlet (first inlet 41), enters the heat exchange tube side after being uniformly distributed by the flow equalization plate 46. Inside the tube, the liquid working fluid A absorbs heat from the high-temperature gaseous working fluid B on the shell side and continuously evaporates. That is, along the tube length, the proportion of gaseous fluid gradually increases while the proportion of liquid gradually decreases. At the outlet, the gaseous working fluid produced by evaporation in the tube side, carrying unevaporated liquid working fluid, flows into the right water chamber (second storage chamber 412). (The ideal outlet condition is complete evaporation in the tube side and...) The gaseous working medium A (without liquid) is separated from the filter screen in the right water chamber by the filter screen and drips down onto the bottom baffle plate 418. It then enters the liquid storage tank formed by the baffle plate 418 and the cylinder 413 through the flow hole (flow hole 419) on the vertical baffle plate 421. After a certain liquid level is formed in the tank, the liquid working medium is ejected to the left water chamber tube return port 410 by the ejector connected to the tube side outlet 416.

[0063] The present invention also provides an air conditioner that includes the aforementioned refrigeration system.

[0064] The refrigeration system of this invention adopts an ejector method to guide the separated liquid refrigerant back to the inlet end, avoiding a large amount of liquid refrigerant from entering the compressor. Especially under low load conditions, the exhaust is bypassed to the inlet end, solving the problem of poor liquid flow uniformity caused by the small inlet flow of the tube side. The condenser-evaporator (second heat exchanger 4) of this invention has differentiated openings on the inlet flow uniform plate of the tube side, matching the uneven heat transfer of the shell side, and improving the problem of liquid carryover at the outlet caused by the small heat transfer of the small and medium-sized tubes.

[0065] This invention can solve the problem of uneven heat exchange in condenser-evaporators and liquid carryover caused by incomplete evaporation at the outlet due to uneven liquid inlet under low load.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A refrigeration system characterized by: Comprise: The first compressor (1), the first heat exchanger (2), the first valve (3), the second heat exchanger (4) and the ejector (5), the first compressor (1), the first heat exchanger (2), the first valve (3) and the second heat exchanger (4) are connected to form at least part of the structure of the first refrigeration circuit, the first inlet end (51) of the ejector (5) is communicated to the outlet end of the second heat exchanger (4), the second inlet end (52) is communicated to the exhaust end of the first compressor (1), and the first outlet end (53) of the ejector (5) is communicated to the inlet end of the second heat exchanger (4).

2. The refrigeration system according to claim 1, wherein: Further comprising a first pipeline (101), a second pipeline (102), a third pipeline (103), a fourth pipeline (104), a fifth pipeline (105) and a sixth pipeline (106), the first pipeline (101) is communicated between the outlet of the first compressor (1) and the inlet of the first heat exchanger (2), the second pipeline (102) is communicated between the outlet of the first heat exchanger (2) and the first inlet (41) of the second heat exchanger (4), the first valve (3) is arranged on the second pipeline (102), the third pipeline (103) is communicated between the first outlet (42) of the second heat exchanger (4) and the inlet of the first compressor (1), one end of the fourth pipeline (104) is communicated to the outlet end of the second heat exchanger (4), and the other end is communicated with the first inlet end (51) of the ejector (5), one end of the fifth pipeline (105) is communicated to the exhaust end of the first compressor (1), and the other end is communicated with the second inlet end (52) of the ejector (5), one end of the sixth pipeline (106) is communicated to the inlet end of the second heat exchanger (4), and the other end is communicated with the first outlet end (53) of the ejector (5).

3. The refrigeration system according to claim 2, wherein: The first valve (3) is a throttling device capable of adjusting the opening degree, the second valve (6) is arranged on the third pipeline (103), the third valve (7) is arranged on the fifth pipeline (105), and the fourth valve (8) is arranged on the fourth pipeline (104); The second valve (6), the third valve (7) and the fourth valve (8) are all control valves capable of controlling the opening and closing of the pipeline, when the operating condition load of the refrigeration system is less than the preset value, the fourth valve (8) can be controlled to be closed, and the third valve (7) can be controlled to be opened; When the operating condition load of the refrigeration system is greater than or equal to the preset value, the fourth valve (8) and the third valve (7) can be controlled to be opened.

4. The refrigeration system according to claim 2, wherein: Further comprising a second compressor (9), a third heat exchanger (10), a sixth valve (11), a seventh pipeline (107), an eighth pipeline (108) and a ninth pipeline (109), one end of the seventh pipeline (107) is communicated to the outlet end of the second compressor (9), the other end is communicated with the second inlet (43) of the second heat exchanger (4), one end of the eighth pipeline (108) is communicated to the gas inlet end of the second compressor (9), the other end is communicated with the refrigerant outlet (10a) of the third heat exchanger (10), one end of the ninth pipeline (109) is communicated to the second outlet (44) of the second heat exchanger (4), the other end is communicated with the refrigerant inlet (10b) of the third heat exchanger (10), the sixth valve (11) is arranged on the eighth pipeline (108) and can adjust the refrigerant flow, and the fifth valve (12) is further arranged on the ninth pipeline (109).

5. The refrigeration system of claim 2, wherein: The second heat exchanger (4) comprises a shell (40), one end of the shell (40) is provided with a first liquid storage chamber (45), a flow equalizing plate (46) and a tube plate (47), the first liquid storage chamber (45) is provided with a tube side inlet and a liquid return port (410), the tube side inlet is the first inlet (41), the tube side inlet is communicated with the outlet end of the second pipeline (102), the liquid return port (410) is communicated with the outlet end of the sixth pipeline (106), the first liquid storage chamber (45) forms a liquid inlet chamber of the second heat exchanger (4), a plurality of heat exchange tubes (48) are arranged in the shell (40), the flow equalizing plate (46) is located between the first liquid storage chamber (45) and the tube plate (47), so that the first liquid storage chamber (45) is communicated with the tube plate (47) through the flow equalizing plate (46), and the tube plate (47) is connected with a plurality of heat exchange tubes (48).

6. The refrigeration system of claim 5, wherein: A plurality of flow equalizing holes (49) are arranged on the flow equalizing plate (46), one end of the flow equalizing hole (49) is communicated with the heat exchange tube (48) one by one through the tube plate (47), and the other end of the flow equalizing hole (49) is communicated with the first liquid storage chamber (45); a plurality of flow equalizing holes (49) are divided into a plurality of rows in the vertical direction, and in the two rows of flow equalizing holes adjacent in the vertical direction, the total flow area of the flow equalizing holes in the upper row is greater than that of the flow equalizing holes in the lower row, and the hole diameter of the flow equalizing holes in the upper row is greater than that of the flow equalizing holes in the lower row.

7. The refrigeration system of claim 6, wherein: Along the direction from the upper row to the lower row in the vertical direction, the total flow area of each row of flow equalizing holes gradually decreases, and the hole diameter of the flow equalizing holes of each row gradually decreases from top to bottom.

8. The refrigeration system of claim 5, wherein: Another end of the shell (40) is connected with a flange (411), a second liquid storage chamber (412) is formed inside the flange (411), the second liquid storage chamber (412) is communicated with the outlet end of the shell (40), and a cylinder body (413) is further connected to the end of the flange (411) away from the shell (40), the cylinder body (413) is provided with a pipe passage gas outlet and a pipe passage liquid outlet (416), the pipe passage gas outlet is the first outlet (42), the pipe passage gas outlet is communicated with the inlet end of the third pipeline (103), and the pipe passage liquid outlet (416) is communicated with the inlet end of the fourth pipeline (104).

9. The refrigeration system of claim 8, wherein: The inside of the cylinder body (413) is provided with a first gas baffle (414), a filter (415) is connected and arranged at the lower end of the first gas baffle (414), and the pipe passage gas outlet is opposite to the first gas baffle (414) in the height direction, so that the fluid from the shell (40) is blocked and separated by the first gas baffle (414), and then discharged through the pipe passage gas outlet after passing through the filter (415).

10. The refrigeration system of claim 9, wherein: The inside of the cylinder body (413) is further provided with a second gas baffle (417), the second gas baffle (417) extends along the horizontal direction to form a horizontal gas baffle, the second gas baffle (417) is connected with the filter (415), and the second gas baffle (417) is connected with the horizontal side inner wall of the cylinder body (413), the first gas baffle (414) extends along the vertical direction to form a vertical gas baffle, and the upper end of the first gas baffle (414) extends to be connected with the top inner wall of the cylinder body (413).

11. The refrigeration system of claim 9, wherein: The inside of the cylinder body (413) is further provided with a liquid baffle (418), at least part of the structure of the liquid baffle (418) is located above the pipe passage liquid outlet (416) and below the first gas baffle (414), and the liquid baffle (418) is further provided with a flow-through hole (419) to guide the liquid blocked and separated by the liquid baffle (418) to the pipe passage liquid outlet (416).

12. The refrigeration system of claim 11, wherein: The liquid baffle (418) comprises a horizontal liquid baffle (420) and a vertical liquid baffle (421), the horizontal liquid baffle (420) extends in a horizontal direction, the horizontal liquid baffle (420) is located above the tube-pass liquid outlet (416) and below the first gas baffle (414), the vertical liquid baffle (421) extends in a vertical direction, an upper end of the vertical liquid baffle (421) is connected with the horizontal liquid baffle (420), and a lower end of the vertical liquid baffle (421) is connected with an inner wall of a bottom of the cylinder (413), and the flow-through hole (419) is formed in the vertical liquid baffle (421) in a direction penetrating through two end faces of the vertical liquid baffle (421).

13. An air conditioner characterized by comprising: A refrigeration system comprising the system of any one of claims 1-12.

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