Air conditioning refrigeration system

Abstract

The present application provides a kind of air conditioning refrigeration system, comprising sequentially connected compressor, condenser, first throttling element and evaporator forming refrigeration cycle, wherein, the evaporator has liquid distributor and gas collector, the top end of the gas collector is communicated with the suction port of the compressor, the inlet of the liquid distributor is communicated with the outlet of the first throttling element, the air conditioning refrigeration system further comprises liquid storage tank for storing the retained liquid flowed out from the bottom end of the gas collector, the liquid stored in the liquid storage tank can be controlled to flow into the liquid distributor. The present application effectively prevents the liquid retained in the bottom area of the gas collector from liquid sealing each heat dissipation branch in the evaporator, ensures the circulation amount of refrigerant in the refrigeration system, guarantees the performance of the refrigeration system, also ensures each moving friction component in the compressor to be fully lubricated, improves the reliability of the compressor.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning technology, and specifically relates to an air conditioning refrigeration system. Background Technology

[0002] In current vapor compression refrigeration cycles, the compressor is a crucial component, serving as the power source for refrigerant flow within the system. Most compressors in refrigeration cycles require ample lubrication to ensure the smooth operation of moving parts such as the crankshaft, bearings, and connecting rods, and to enhance the sealing of moving surfaces within the compression chamber. However, lubricating oil and refrigerant exhibit mutual solubility and separation, leading to oil stagnation in the refrigeration system. This often results in insufficient oil return flow under harsh operating conditions, causing the compressor to operate with insufficient oil, leading to decreased efficiency, overheating, and potential compressor seizure or damage.

[0003] There are many reasons for poor oil return, such as dead zones in the structural design, low refrigerant flow rate during low-frequency operation which cannot carry more oil back to the compressor, and excessively high gas collection pipe causing insufficient flow rate and oil return in the bottom branch.

[0004] In common air conditioning refrigeration system designs, oil separators are used to pre-separate lubricating oil from the high-pressure exhaust. Through structures such as oil return capillaries, the separated lubricating oil returns to the compressor's suction pipe under the influence of the high and low pressure difference, thus minimizing the amount of lubricating oil flowing in the refrigeration system. However, in air conditioning refrigeration systems without oil separators, achieving safe oil return is a significant issue that system and structural designers need to consider.

[0005] In air conditioning systems without a gas-liquid separator, preventing compressor liquid slugging is a critical issue (unevaporated refrigerant liquid in the evaporator enters the compressor along with high-speed refrigerant gas, and the liquid impacting the compressor's compression surface can easily cause damage). To prevent liquid refrigerant from the evaporator from entering the compressor, the return main is usually connected above the highest possible liquid level in the evaporator's collector main. However, this easily leads to liquid refrigerant and lubricating oil accumulating at the bottom of the collector main. This is because the refrigerant flow rate and velocity in the bottom branches are low, and they cannot carry enough liquid refrigerant and / or lubricating oil upwards. Over time, this causes liquid refrigerant and some lubricating oil to accumulate at the bottom of the collector main. As the liquid level gradually rises, a liquid seal can easily form in the bottom branches, further reducing the refrigerant flow and causing a "liquid storage" phenomenon at the bottom of the evaporator. Obviously, this liquid refrigerant will also contain more lubricating oil, easily leading to insufficient refrigerant circulation and insufficient oil return in the refrigeration system.

[0006] Authorized utility model patents 201920758930.1 and 201420133297.4 propose connecting an oil return pipe to the main return pipe at the bottom of the evaporator's gas collecting pipe assembly, using pressure difference to draw the liquid remaining at the bottom of the gas collecting pipe back to the compressor. However, both of these authorized utility model patents have some problems: 1) After the system is shut down and left to stand, the high and low pressures of the air conditioning refrigeration system will gradually reach pressure balance. The high-pressure end will squeeze the liquid refrigerant to accumulate in the evaporator, making it easy for the liquid refrigerant at the bottom of the evaporator to return directly to the compressor through the oil return pipe. The compressor suction pipe may even reach the compressor oil sump, which will cause the compressor to start with liquid and be prone to liquid slugging during the next startup; 2) The diameter of the return oil pipe is specified, but the length of the return oil pipe is not mentioned. Only the design principle of the diameter of the return oil pipe is proposed. In actual design, the specifications and length of the return oil pipe need to be determined according to the pressure difference and the return flow rate. If the diameter of the return oil pipe is small or the return oil pipe is longer, the return flow rate will be smaller, which may not be able to achieve safe return. In the end, the refrigerant liquid and lubricating oil will still accumulate at the bottom of the evaporator. Summary of the Invention

[0007] Therefore, the present invention provides an air conditioning refrigeration system that can solve the technical problems in the prior art where liquid refrigerant and lubricating oil easily accumulate at the bottom of the evaporator manifold, leading to a liquid seal at the bottom of the evaporator, insufficient refrigerant circulation, insufficient oil return, and the risk of liquid slugging in the compressor.

[0008] To address the aforementioned problems, this invention provides an air conditioning refrigeration system comprising a compressor, a condenser, a first throttling element, and an evaporator connected in sequence to form a refrigeration cycle. The evaporator has a liquid distributor and a gas collecting pipe. The top end of the gas collecting pipe is connected to the suction port of the compressor, and the inlet of the liquid distributor is connected to the outlet of the first throttling element. The air conditioning refrigeration system further includes a liquid storage tank for storing accumulated liquid flowing from the bottom of the gas collecting pipe. The liquid stored in the liquid storage tank can be controlled to flow into the liquid distributor.

[0009] In some embodiments, the bottom of the liquid storage tank is connected to the bottom of the gas collecting pipe via a first pipeline, and a first one-way valve is connected in series on the first pipeline. The one-way valve has a unidirectional flow direction from the gas collecting pipe to the liquid storage tank.

[0010] In some embodiments, a second pipeline is connected to the first pipeline between the first check valve and the liquid storage tank. The second pipeline is connected between the first pipeline and the liquid distributor. A second check valve is connected in series on the second pipeline. The unidirectional flow direction of the second check valve is from the liquid storage tank to the liquid distributor.

[0011] In some embodiments, the compressor's exhaust port is controllably connected to the liquid storage tank via a first bypass throttling line.

[0012] In some embodiments, the first bypass throttling line includes a third line connecting the compressor's exhaust port and the liquid storage tank, wherein a second throttling element and an on / off valve are connected in series on the third line.

[0013] In some embodiments, the on / off valve is a solenoid two-way valve, the height of the liquid storage tank is lower than the height of the bottom end of the gas collecting pipe, and the solenoid two-way valve is in a cut-off state when de-energized and in a conducting state when energized.

[0014] In some embodiments, the on / off valve has a switchable first connecting flow path and a second connecting flow path. The air conditioning refrigeration system further includes a fourth pipeline, one end of which is controllably connected to the liquid storage tank via the first connecting flow path, and the other end of which is connected to the suction port of the compressor. The second connecting flow path is connected in series within the third pipeline to achieve controllable connection between the second throttling element and the liquid storage tank.

[0015] In some embodiments, the on / off valve is a solenoid three-way valve, and when the solenoid three-way valve is de-energized, the first connecting flow path is in a conducting state and the second connecting flow path is in a cut-off state; when the solenoid three-way valve is energized, the first connecting flow path is in a cut-off state and the second connecting flow path is in a conducting state.

[0016] In some embodiments, the liquid storage tank is provided with a liquid level detection component, which is used to detect the high and low levels of the liquid stored in the liquid storage tank. The on / off valve is configured such that: when the liquid level in the liquid storage tank is high, the on / off valve is energized, and when the liquid level is low, the on / off valve is de-energized.

[0017] In some embodiments, the outlet of the first throttling element is connected to the inlet of the liquid separator via a fifth pipe, the fifth pipe passing through the liquid storage space of the liquid storage tank; and / or, the air conditioning refrigeration system is used in a computer room air conditioner.

[0018] The air conditioning refrigeration system provided by this invention has the following beneficial effects:

[0019] On the one hand, the liquid accumulated at the bottom of the gas collecting pipe is promptly transferred and stored in a liquid receiver outside the evaporator, effectively preventing liquid accumulation at the bottom of the gas collecting pipe from sealing the heat dissipation branches in the evaporator, ensuring the circulation of refrigerant in the refrigeration system, and guaranteeing the performance of the refrigeration system. On the other hand, the liquid stored in the liquid receiver can be controlled to flow into the distributor head, so that this part of the liquid merges with the refrigerant flowing out of the first throttling element and enters the evaporator. Since the liquid refrigerant in the liquid flows through the evaporator for heat exchange and vaporization before being sucked into the compressor, it can prevent liquid-laden start-up and liquid slugging during compressor startup. At the same time, it can also ensure the smooth return of lubricating oil, thereby ensuring that all moving friction parts in the compressor are adequately lubricated and improving the reliability of the compressor.

[0020] By connecting a first check valve in series on the first pipeline, it is ensured that the liquid accumulated at the bottom of the gas collecting pipe can smoothly enter the storage tank for storage and will not flow back from the storage tank to the gas collecting pipe. The design of the first check valve simplifies the control logic of the air conditioning refrigeration system and reduces the complexity of the system design. By connecting a second check valve in series on the second pipeline, the unidirectional conduction characteristic of the second check valve ensures that the liquid in the storage tank can only flow from the storage tank to the distributor head and will not flow back. At the same time, since there is a connection between the second pipeline and the first pipeline, and due to the reverse cut-off characteristic of the first check valve, the liquid in the storage tank will not flow back into the gas collecting pipe during the process of transporting the liquid to the distributor head. The pipeline design is simple and the layout is convenient.

[0021] The compressor's exhaust port is controllably connected to the liquid storage tank via a first bypass throttling pipe. Through the first bypass throttling pipe, a small portion of the high-temperature, high-pressure gas flow discharged from the compressor can be introduced into the liquid storage tank after partial pressure reduction. This portion of gaseous refrigerant can then be used to drive the liquid stored in the liquid storage tank. Without the need for a separate liquid pumping device, the liquid stored in the liquid storage tank can be transported to the distributor and enter the evaporator for further heat exchange and vaporization. This simplifies the structure and reduces system construction costs.

[0022] By controlling the on / off state of the first and second connecting flow paths, selective connection between the storage space of the liquid storage tank and the suction port or exhaust port of the compressor can be achieved. When the first connecting flow path is connected, the storage space of the liquid storage tank is connected to the suction port of the compressor, which allows the liquid accumulated at the bottom of the gas collecting pipe to flow into the liquid storage tank quickly under the pressure difference between the gas collecting pipe and the suction port. Attached Figure Description

[0023] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of the ventilation device according to an embodiment of the present invention from one perspective;

[0025] Figure 2 This is a three-dimensional structural schematic diagram of the ventilation device according to an embodiment of the present invention from another perspective.

[0026] The attached figures are labeled as follows:

[0027] 1. Compressor; 2. Condenser; 21. Gas distribution pipe; 22. Liquid collection pipe; 3. First throttling element; 4. Evaporator; 41. Liquid distributor head; 411. Liquid distribution branch pipe; 42. Gas collection pipe; 5. Liquid receiver; 6. Liquid level detection component; 7. Oil separator; 71. Third throttling element;

[0028] 100, First pipeline; 101, First check valve; 200, Second pipeline; 201, Second check valve; 300, Third pipeline; 301, Second throttling element; 302, On / off valve; 400, Fourth pipeline; 500, Fifth pipeline. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] 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° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0032] 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.

[0033] See also Figures 1 to 2As shown, according to an embodiment of the present invention, an air conditioning refrigeration system is provided, including a compressor 1, a condenser 2, a first throttling element 3, and an evaporator 4 connected in sequence to form a refrigeration cycle. The evaporator 4 has a liquid distributor 41 and a gas collecting pipe 42. The liquid distributor 41 is connected to each cooling branch within the evaporator 4 through multiple liquid distributor branches 411 (in one specific embodiment, the lengths of the liquid distributor branches 411 are different or connected in series with regulating pipes of different lengths). Under normal circumstances, the accumulated liquid (a mixture of refrigerant and lubricating oil) at the bottom of the gas collecting pipe 42... The top end of the gas collecting pipe 42 is connected to the suction port of the compressor 1, and the inlet of the liquid distributor 41 is connected to the outlet of the first throttling element 3. Specifically, the exhaust port of the compressor 1 is connected to the gas distribution pipe 21 of the condenser 2 through the exhaust pipe. The gas distribution pipe 21 distributes the high-temperature and high-pressure refrigerant gas into various branches in the condenser 2 through several gas distribution branches (not labeled in the figure), where phase change condensation and liquefaction are achieved. The gas is then collected into the liquid collecting pipe 22 through the liquid collecting branch pipe (not labeled in the figure). The total outlet of the liquid collecting pipe 22 is connected to the first throttling element 3 (generally an electric one). The inlet of the expansion valve and the outlet of the first throttling element 3 are connected to the distributor head 41. The high-pressure refrigerant is throttled and cooled down by the first throttling element 3. The distributor head 41 distributes the low-temperature, low-pressure refrigerant liquid to the various branches in the evaporator 4 through the various distribution branches 411. In the evaporator 4, phase change evaporation and vaporization are achieved. The liquid is collected in the gas collecting branch (not marked in the figure) to the gas collecting pipe 42. The main outlet of the gas collecting pipe 42 is connected to the suction pipe (not marked in the figure). The suction pipe is connected to the suction port of the compressor 1, thus forming a complete refrigeration cycle. The air conditioning refrigeration system also includes a liquid receiver tank. 5. Used to store the accumulated liquid (i.e., the mixture of liquid refrigerant and lubricating oil mentioned above) flowing out of the bottom of the gas collecting pipe 42. The liquid stored in the liquid storage tank 5 can be controlled to flow into the liquid distributor 41. In a feasible embodiment, a corresponding pumping device can be used to pump the liquid accumulated at the bottom of the gas collecting pipe 42 into the liquid storage tank 5, and the liquid stored in the liquid storage tank 5 can be pumped to the liquid distributor 41 by the corresponding pumping device. It is understood that the aforementioned gas collecting pipe 42 can generally be set to a vertical state, but it can also be set to an inclined state.

[0034] In this technical solution, on the one hand, the liquid collected at the bottom of the gas collecting pipe 42 is promptly transferred and stored in the liquid storage tank 5 outside the evaporator 4, effectively preventing the liquid from accumulating at the bottom of the gas collecting pipe 42 and sealing the heat dissipation branches in the evaporator 4, ensuring the circulation of refrigerant in the refrigeration system and guaranteeing the performance of the refrigeration system; on the other hand, the liquid stored in the liquid storage tank 5 can be controlled to flow into the liquid distributor 41, so that this part of the liquid merges with the refrigerant flowing out of the first throttling element 3 and enters the evaporator 4. Since the liquid refrigerant in the liquid flows through the evaporator 4 for heat exchange and vaporization before being sucked into the compressor 1, it can prevent the start-up of the compressor 1 with liquid and the occurrence of liquid slugging. At the same time, it can also ensure the smooth return of lubricating oil, thereby ensuring that the moving friction parts in the compressor are fully lubricated and improving the reliability of the compressor.

[0035] See details Figure 1 and Figure 2 As shown, in some embodiments, the bottom of the liquid storage tank 5 is connected to the bottom of the gas collecting pipe 42 through a first pipe 100, and a first one-way valve 101 is connected in series on the first pipe 100. The one-way flow direction of the first one-way valve 101 is from the gas collecting pipe 42 to the liquid storage tank 5.

[0036] In this technical solution, by connecting the first one-way valve 101 in series on the first pipeline 100, it can be ensured that the liquid accumulated at the bottom of the gas collecting pipe 42 can smoothly enter the liquid storage tank 5 for storage and will not flow back from the liquid storage tank 5 to the gas collecting pipe 42. The design of the first one-way valve 101 can simplify the control logic of the air conditioning refrigeration system and reduce the complexity of the system design.

[0037] In a preferred embodiment, a second pipeline 200 is connected to the first pipeline 100 located between the first one-way valve 101 and the liquid storage tank 5. The second pipeline 200 is connected between the first pipeline 100 and the liquid distributor 41, and a second one-way valve 201 is connected in series on the second pipeline 200. The one-way flow direction of the second one-way valve 201 is from the liquid storage tank 5 to the liquid distributor 41.

[0038] In this technical solution, by connecting a second one-way valve 201 in series on the second pipeline 200, the one-way conduction characteristic of the second one-way valve 201 is used to ensure that the liquid in the storage tank 5 can only flow from the storage tank 5 to the distributor head 41, and will not flow in the opposite direction. At the same time, since there is a connection between the second pipeline 200 and the first pipeline 100, and due to the reverse cut-off characteristic of the first one-way valve 101, the liquid in the storage tank 5 will not flow back into the gas collecting pipe 42 during the process of transporting the liquid to the distributor head 41. The pipeline design is simple and the layout is convenient.

[0039] In some embodiments, the exhaust port of the compressor 1 is controllably connected to the liquid storage tank 5 via a first bypass throttling pipe. Through the first bypass throttling pipe, a small portion of the high-temperature and high-pressure gas flow discharged from the compressor 1 can be introduced into the liquid storage tank 5 after partial depressurization. This portion of gaseous refrigerant can then be used to drive the liquid stored in the liquid storage tank 5. Without the need for a separate liquid pumping device, the liquid stored in the liquid storage tank 5 can be transported to the distributor head 41 and enter the evaporator 4 for further heat exchange and vaporization. This simplifies the structure and reduces the system construction cost.

[0040] In one specific embodiment, the first bypass throttling pipeline includes a third pipeline 300 connecting the exhaust port of the compressor 1 and the liquid storage tank 5. A second throttling element 301 and an on / off valve 302 are connected in series on the third pipeline 300. The second throttling element 301 can generally be a capillary tube with a suitable flow diameter and length. The on / off valve 302 is used to control the opening and closing of the third pipeline 300, thereby reasonably controlling the selective entry of the depressurized exhaust gas flow into the liquid storage tank 5 to drive the liquid into the distributor head 41.

[0041] In another preferred embodiment, an oil separator 7 is connected in series with the third pipeline 300. The inlet of the oil separator 7 is connected to the exhaust port of the compressor 1, and the oil return port of the oil separator 7 is connected to the intake port of the compressor 1 through a third throttling element 71. In this way, the lubricating oil in the exhaust gas can be separated in advance by the oil separator 7 and returned to the compressor 1, ensuring the reliable operation of the compressor 1. The aforementioned third throttling element 71 can also be a capillary tube. It is understood that the outlet pipe of the oil separator 7 is connected to the gas distribution pipe 21 of the condenser 2. It is understood that in another feasible embodiment, the exhaust pipe of the compressor 1 can also be connected to the gas distribution pipe 21 of the condenser 2 separately through a corresponding pipeline. In this case, the inlet of the oil separator 7 is connected to the aforementioned third pipeline 300, and the outlet of the oil separator 7 is connected to the gas distribution pipe 21 of the condenser 2.

[0042] See details Figure 1As shown, in this specific embodiment, the on / off valve 302 is a solenoid two-way valve, specifically a solenoid on / off valve. At this time, the height of the liquid storage tank 5 is lower than the height of the bottom end of the gas collecting pipe 42, so that the liquid accumulated in the gas collecting pipe 42 can flow into the liquid storage tank 5 by its own weight. It can be understood that at this time, when the first one-way valve 101 is opened by the liquid's own weight, the gaseous portion of the refrigerant in the sealed liquid storage tank 5 will enter the gas collecting pipe 42 through the open first one-way valve 101 and ultimately enter the refrigeration cycle. The electromagnetic two-way valve is in a cut-off state when de-energized and in a conducting state when energized. Specifically, when the electromagnetic two-way valve is in the cut-off state, the liquid in the liquid storage tank 5 will not enter the distributor head 41 through the second one-way valve 201 due to the lack of necessary driving force. However, when the electromagnetic two-way valve is in the conducting state, the depressurized refrigerant gas flow will drive the liquid in the liquid storage tank 5 to enter the distributor head 41 through the second one-way valve 201, thereby allowing this portion of liquid refrigerant and lubricating oil to participate in the refrigeration cycle, ensuring sufficient refrigerant circulation. It should be noted that the electromagnetic two-way valve in this technical solution is in a cut-off state when de-energized and in a conducting state when energized, which helps to save energy.

[0043] As another specific embodiment, see Figure 2 As shown, the on / off valve 302 has a switchable first connection flow path (e.g., Figure 2 The OM flow path in the middle) and the second connected flow path (e.g. Figure 2 The air conditioning refrigeration system further includes a fourth pipe 400, one end of which is controllably connected to the liquid storage tank 5 via the first connecting pipe, and the other end of which is connected to the suction port of the compressor 1. The second connecting pipe is connected in series within the third pipe 300 to achieve controllable connection between the second throttling element 301 and the liquid storage tank 5.

[0044] In this technical solution, selective connection between the storage space of the liquid storage tank 5 and the suction port or discharge port of the compressor 1 can be achieved by controlling the on / off state of the first and second connecting flow paths. When the first connecting flow path is connected, the storage space of the liquid storage tank 5 is connected to the suction port of the compressor 1. This allows the liquid accumulated at the bottom of the gas collecting pipe 42 to flow into the liquid storage tank 5 quickly under the pressure difference between the gas collecting pipe 42 and the suction port. It should be noted that the relative height between the bottom of the liquid storage tank 5 and the bottom of the gas collecting pipe 42 can be flexibly adjusted according to actual needs, without limiting the bottom height of the gas collecting pipe 42 to be higher than that of the liquid storage tank 5. When the second connecting flow path is connected, the storage space of the liquid storage tank 5 is connected to the discharge port of the compressor 1 (specifically via the aforementioned first bypass throttling pipe). At this time, the refrigerant gas at higher pressure enters the liquid storage tank 5, forming a driving force on the liquid, thereby allowing the liquid in the liquid storage tank 5 to flow into the liquid distributor 41 through the second throttling element 301, realizing the reheating and vaporization of this part of the liquid.

[0045] The aforementioned first and second connecting flow paths can each be implemented by switching on and off using a solenoid two-way valve. However, as a preferred implementation, the on / off valve 302 is a solenoid three-way valve (e.g., Figure 2 As shown, specifically a two-position three-way valve, the electromagnetic three-way valve has the following configuration: when de-energized, the first connecting flow path is in a conducting state and the second connecting flow path is in a cut-off state; when energized, the first connecting flow path is in a cut-off state and the second connecting flow path is in a conducting state. This technical solution achieves the aforementioned purpose by using different flow paths of a single electromagnetic three-way valve, resulting in a more compact structure and reducing the number of assembly parts. This reduces the number of potential failure points in the air conditioning refrigeration system and lowers subsequent after-sales maintenance costs. Furthermore, this technical solution saves energy by having the first connecting flow path in a cut-off state and the second connecting flow path in a conducting state when the electromagnetic three-way valve is energized, and the first connecting flow path in a conducting state and the second connecting flow path in a cut-off state when the electromagnetic three-way valve is de-energized.

[0046] See details Figure 1 and Figure 2As shown, in a preferred embodiment, the liquid storage tank 5 is equipped with a liquid level detection component 6. The liquid level detection component 6 is used to detect the high and low levels of the liquid stored in the liquid storage tank 5. The on / off valve 302 is configured such that: when the liquid level in the liquid storage tank 5 is high, the on / off valve 302 is energized; when the liquid level is low, the on / off valve 302 is de-energized. That is, when there is a lot of liquid stored in the liquid storage tank 5, it indicates that the amount of refrigerant in the air conditioning refrigeration cycle may be insufficient. At this time, the exhaust port of the compressor 1 is connected to the liquid storage tank 5 to send the liquid in the liquid storage tank 5 into the refrigeration cycle to participate in the circulation. When there is a little liquid stored in the liquid storage tank 5, there may be a risk that the liquid accumulated at the bottom of the gas collecting pipe 42 may not be output to the liquid storage tank 5 in time. Therefore, at this time, the suction port of the compressor 1 is connected to the liquid storage tank 5 to use the pressure difference between the gas collecting pipe 42 and the suction port to accelerate the discharge of the accumulated liquid and prevent the formation of a liquid seal in the gas collecting pipe 42.

[0047] The aforementioned liquid level detection component 6 can be a commonly used liquid level gauge. Specifically, the liquid level gauge is equipped with at least a low liquid level switch and a high liquid level switch. When more and more refrigerant liquid enters the liquid storage tank 5 and the liquid level rises, the float of the high liquid level rises, causing the high liquid level switch to close. At this time, the aforementioned electromagnetic three-way valve or electromagnetic two-way valve is energized (i.e., the electromagnetic valve is energized), and part of the high-pressure refrigerant gas bypasses and enters the liquid storage tank 5 after being depressurized by the second throttling element 301. The squeezed refrigerant liquid enters the distributor head 41 through the second one-way valve 201 for recycling. As more and more refrigerant gas enters the liquid storage tank 5, the corresponding liquid in the liquid storage tank 5 decreases and the liquid level drops. The float of the low liquid level drops, causing the low liquid level switch to open. At this time, the electromagnetic three-way valve or electromagnetic two-way valve is de-energized (i.e., the electromagnetic valve is de-energized), and no more refrigerant gas enters the liquid storage tank 5. The refrigerant liquid remaining in the liquid storage tank 5 no longer enters the distributor head 41. It is understandable that the aforementioned description assumes that when the float rises, the corresponding magnetic switch closes, and when the float falls, the corresponding magnetic switch opens. In fact, the reverse also applies. This will not be elaborated upon here. The aforementioned level detection component 6 can also be a float level switch, which is a mature application technology and product. Its principle will not be described in detail here. When the liquid level rises to the highest level, both the high-level and low-level floats rise, and both magnetic switches are closed, indicating that the liquid level is indeed high. When the liquid level gradually decreases, the high-level float falls, but the low-level float continues to rise. The high-level magnetic switch opens while the low-level magnetic switch closes, indicating that the liquid level is in the middle range. When the liquid level decreases again, both the high-level and low-level floats fall, and both magnetic switches open. When the liquid level rises, the magnetic switch action is reversed, from open to closed; that is, when the liquid level decreases, the magnetic switch action is from closed to open.

[0048] In some embodiments, the outlet of the first throttling element 3 is connected to the inlet of the liquid distributor 41 via a fifth pipe 500. The fifth pipe 500 passes through the liquid storage space of the liquid storage tank 5. That is, when the refrigerant flowing out of the outlet of the first throttling element 3 flows through the fifth pipe 500, it will exchange heat with the liquid in the liquid storage tank 5, so that the temperature of the refrigerant in the liquid storage tank 5 is the same as or approximately the same as the temperature of the refrigerant at the outlet of the first throttling element 3. The purpose is to ensure that the liquid in the liquid storage tank 5 mixes with the refrigerant liquid at the outlet of the through pipe through the second one-way valve 201 to maintain a consistent temperature before entering the liquid distributor 41, thereby maintaining the stability of the refrigeration system as much as possible.

[0049] In a preferred embodiment, the air conditioning system is used in a computer room air conditioner. In this case, only the condenser 2 (and the outdoor fan used with it) is placed on the outdoor side, while the compressor 1, evaporator 4, first throttling element 3 and liquid storage tank 5 are placed on the indoor side.

[0050] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0051] 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. An air conditioning refrigeration system, comprising a compressor (1), a condenser (2), a first throttling element (3), and an evaporator (4) connected sequentially to form a refrigeration cycle, wherein, The evaporator (4) has a liquid distributor (41) and a gas collecting pipe (42). The top end of the gas collecting pipe (42) is connected to the suction port of the compressor (1), and the inlet of the liquid distributor (41) is connected to the outlet of the first throttling element (3). The air conditioning refrigeration system further includes a liquid storage tank (5) for storing the accumulated liquid flowing out of the bottom end of the gas collecting pipe (42). The liquid stored in the liquid storage tank (5) can be controlled to flow into the liquid distributor (41). The bottom of the liquid storage tank (5) is connected to the bottom of the gas collecting pipe (42) through a first pipeline (100), and a first one-way valve (101) is connected in series on the first pipeline (100). The one-way direction of the first one-way valve (101) is from the gas collecting pipe (42) to the liquid storage tank (5). A second pipeline (200) is connected to the first pipeline (100) between the first one-way valve (101) and the liquid storage tank (5). A pipeline (200) is connected between the first pipeline (100) and the distributor head (41), and a second one-way valve (201) is connected in series on the second pipeline (200). The one-way flow direction of the second one-way valve (201) is from the liquid storage tank (5) to the distributor head (41). The outlet of the first throttling element (3) is connected to the inlet of the distributor head (41) via a fifth pipeline (500), which runs through the liquid storage tank. (5) The liquid storage space; the exhaust port of the compressor (1) is controllably connected to the liquid storage tank (5) via the first bypass throttling pipe; the refrigerant flowing out of the outlet of the first throttling element (3) exchanges heat with the liquid in the liquid storage tank (5) when it flows in the fifth pipe (500), so that the liquid in the liquid storage tank (5) mixes with the refrigerant liquid at the outlet of the through pipe through the second one-way valve (201) to achieve a consistent temperature before entering the liquid distributor (41).

2. The air conditioning refrigeration system according to claim 1, characterized in that, The first bypass throttling pipeline includes a third pipeline (300) connecting the exhaust port of the compressor (1) and the liquid storage tank (5), and a second throttling element (301) and an on / off valve (302) are connected in series on the third pipeline (300).

3. The air conditioning refrigeration system according to claim 2, characterized in that, The on / off valve (302) is an electromagnetic two-way valve. The height of the liquid storage tank (5) is lower than the height of the bottom end of the gas collecting pipe (42). The electromagnetic two-way valve is in the cut-off state when de-energized and in the conduction state when energized, so that the liquid accumulated in the gas collecting pipe (42) can flow into the liquid storage tank (5) by its own weight.

4. The air conditioning refrigeration system according to claim 2, characterized in that, The on / off valve (302) has a first connecting flow path and a second connecting flow path that can be switched. The air conditioning refrigeration system also includes a fourth pipe (400). One end of the fourth pipe (400) is controllably connected to the liquid storage tank (5) via the first connecting flow path. The other end of the fourth pipe (400) is connected to the suction port of the compressor (1). The second connecting flow path is connected in series within the third pipe (300) to achieve controllable connection between the second throttling element (301) and the liquid storage tank (5).

5. The air conditioning refrigeration system according to claim 4, characterized in that, The on / off valve (302) is an electromagnetic three-way valve. When the electromagnetic three-way valve is de-energized, the first connecting flow path is in a conducting state and the second connecting flow path is in a cut-off state. When the electromagnetic three-way valve is energized, the first connecting flow path is in a cut-off state and the second connecting flow path is in a conducting state.

6. The air conditioning refrigeration system according to any one of claims 3 to 5, characterized in that, The liquid storage tank (5) is equipped with a liquid level detection component (6). The liquid level detection component (6) is used to detect the high and low levels of the liquid stored in the liquid storage tank (5). The on / off valve (302) is configured such that when the liquid level of the liquid stored in the liquid storage tank (5) is at a high level, the on / off valve (302) is energized, and when the liquid level is at a low level, the on / off valve (302) is de-energized.

7. The air conditioning refrigeration system according to claim 1, characterized in that, The air conditioning system is used in computer room air conditioning.

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