Gas-liquid separation device, evaporator preposed gas-liquid separation configuration and heat pump air conditioning system

Abstract

The invention provides a gas-liquid separation device, evaporator front-mounted gas-liquid separation configuration and a heat pump air conditioning system, the gas-liquid separation device comprises a control valve, an outer contour container, a two-phase flow inlet pipe, a gas phase outlet pipe and a liquid phase outlet pipe, the control valve is arranged on the upper portion of the interior of the outer contour container forming the gas-liquid separation device, and the two-phase flow inlet pipe is connected with the liquid phase outlet pipe. The top of the control valve upper connecting channel is connected with the gas phase outlet pipe, the gas phase outlet pipe is arranged at the side end of the upper part of the outline container, and the liquid phase outlet pipe is arranged at the bottom of the outline container; in addition, the invention provides an evaporator front gas-liquid separation configuration, the gas-liquid separation device is located between the throttling mechanism and the evaporator, the two-phase flow inlet pipe is connected with an outlet of the throttling mechanism, the liquid phase outlet pipe is connected with an inlet of the evaporator, and the gas phase outlet pipe is connected with an outlet of the evaporator. According to the invention, stable gas-liquid separation of the refrigerant in front of the evaporator can be realized, and a technical basis is provided for uniform distribution and effective heat exchange of the refrigerant in multiple channels in the evaporator.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioning, and in particular relates to a gas-liquid separation device, a configuration of a pre-evaporator gas-liquid separation, and a heat pump air conditioning system. Background Art

[0002] In existing heat pump air conditioning (refrigeration) systems, the two-phase refrigerant flowing out of the throttling mechanism is usually introduced directly into the evaporator, or is distributed by a liquid distributor before entering the evaporator. Given the particularity of two-phase flow, even advanced liquid distributors can hardly guarantee that the refrigerant can be effectively distributed evenly under various working conditions, resulting in uneven distribution of refrigerant in different channels of the evaporator, failure of heat exchange area in channels with too much gas phase, and insufficient heat exchange area in channels with too much liquid phase, which further reduces the overall efficiency of the evaporator and even causes problems such as uneven frosting and difficulty in defrosting at low temperatures.

[0003] The above problems can be effectively solved by separating the two-phase refrigerant into gas and liquid before the evaporator and distributing and introducing only the liquid phase refrigerant into the evaporator. However, due to the differences in the flow paths and pressure differences between the gas and liquid phase outlets of the gas-liquid separation device, it is difficult for conventional gas-liquid separation devices to stably and effectively separate the gas and liquid phases in this mode. It is necessary to further develop gas-liquid separation devices that are adaptable to operating condition fluctuations and can stably adjust the liquid level interface, and design the structural configuration of gas-liquid separation before the evaporator and the heat pump air conditioning system. Summary of the invention

[0004] In view of this, the present invention provides a gas-liquid separation device, a configuration of gas-liquid separation before an evaporator, and a heat pump air conditioning system.

[0005] The object of the present invention is achieved in the following manner: A gas-liquid separation device, comprising a control valve, an outer container, a two-phase flow inlet pipe, a gas phase outlet pipe, and a liquid phase outlet pipe, wherein the control valve is placed above the inner part of the outer container constituting the gas-liquid separation device, the top of the upper connecting channel of the control valve is connected to the gas phase outlet pipe, the gas phase outlet pipe is placed at the upper side end of the outer container, and the liquid phase outlet pipe is placed at the bottom of the outer container; The control valve comprises a valve body, a valve core, a connecting rod, a float, a vent hole, and a limit block. An installation cavity and two connecting channels are provided inside the valve body. A sealing surface is provided on the inner wall of the installation cavity. A valve core for matching use is provided in the installation cavity. The truncated cone surface of the valve core is tightly matched with the sealing surface of the installation cavity. The valve core is connected to the top of the connecting rod, and the float is connected to the bottom of the connecting rod. The valve core, the connecting rod and the float form a rigid component, which can slide freely up and down in the lower connecting channel. A limit block is provided at the bottom of the valve body to limit the valve core and prevent it from falling off from the inside of the valve body. A through vent hole is provided in the installation cavity or the lower connecting channel of the valve body. When the gas-liquid separation device is working, the gas-liquid two-phase flow is introduced from the two-phase flow inlet pipe, the gas phase fluid is discharged from the gas phase outlet pipe through the control valve, and the liquid phase fluid is discharged from the liquid phase outlet pipe.

[0006] Optionally, one or more vent holes may be provided. When multiple vent holes are provided, they may be arranged at a certain interval in the vertical direction, and the total flow area of ​​the vent holes is equal to the cross-sectional area of ​​the connecting channel on the upper part of the valve body.

[0007] Preferably, the float can adopt a closed thin shell hollow structure or a lightweight anti-liquid absorption material. The maximum buoyancy provided by the float is greater than the overall gravity of the rigid component, ensuring that the valve core is at the highest position and fits tightly with the sealing surface under high liquid level conditions.

[0008] Furthermore, it is characterized in that the valve core and the connecting rod are of an integrated type or a split type, and the split type adopts a threaded connection method; The connecting rod and the float are connected by threads, and the valve body and the limit block are connected by threads.

[0009] Preferably, the position of the valve core is automatically adjusted according to the liquid level, including: fully open mode, fully closed mode, and partially open mode; Among them, in the fully open mode, when the liquid level is low, the rigid component is under the action of gravity, the valve core is located at the lowest end of the lower connecting channel of the valve body, and the connected area of ​​the vent hole is the largest; In the fully closed mode, when the liquid level is high, the rigid component is under the action of buoyancy, the valve core is located at the top of the installation cavity and closely matches the sealing surface, and the connection area of ​​the vent hole is zero; In the partially open mode, when the liquid level is moderate, the rigid component is acted upon by buoyancy, the valve core portion is located inside the installation cavity, and a portion of the vent hole area is connected.

[0010] A configuration for pre-evaporator gas-liquid separation comprises any one of the above-mentioned gas-liquid separation devices, wherein the gas-liquid separation device is arranged at the inlet side of the evaporator, the two-phase flow inlet pipe introduces the gas-liquid two-phase flow, the liquid phase outlet pipe is connected to the inlet of the evaporator, and the gas phase outlet pipe is connected to the outlet of the evaporator.

[0011] Furthermore, the liquid phase outlet pipe of the gas-liquid separation device is connected to the inlet of the liquid separator, and the outlet of the liquid separator is connected to the inlet of the evaporator.

[0012] A heat pump air conditioning system comprises any one of the above-mentioned evaporator pre-gas-liquid separation configurations, wherein the two-phase flow inlet pipe is connected to the inlet of the throttling mechanism, and the outlet of the evaporator is located on the suction side of the compressor.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The gas-liquid separation device can automatically adjust the valve core opening by relying on the gravity and buoyancy of the valve body assembly, and stabilize the valve core opening, maintain the liquid level unchanged, and discharge the gas phase stably under a given incoming gas phase fraction; (2) The flow paths after the gas and liquid phase outlets of the gas-liquid separation device do not affect the gas-liquid separation effect, and avoid the situation where the liquid phase is flooded and the gas phase pipe outlet is liquid; (3) The evaporator with gas-liquid separation device is used, and the refrigerant single liquid phase is distributed more evenly, with less flow resistance, which is conducive to reducing the evaporator pressure drop; more importantly, the refrigerant flow in each channel of the evaporator is evenly distributed, which fully and effectively utilizes the heat exchange area of ​​the evaporator and improves the heat exchange effect; (4) The gas-liquid separation device can be effectively combined with evaporators of various structural types. The evaporator with the above-mentioned gas-liquid separation device can be widely used in various heat pump air conditioning and refrigeration systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a gas-liquid separation device; Figure 2 The control valve status of the gas-liquid separation device is shown in the figure on the left: fully closed, the middle figure: partially open, and the right figure: fully open; Figure 3 A schematic diagram showing the configuration of a first evaporator having a gas-liquid separation device; Figure 4 A schematic diagram showing the configuration of a second evaporator having a gas-liquid separation device; Figure 5 Schematic diagram of a heat pump air conditioning system based on an evaporator with a gas-liquid separation device.

[0015] Among them, 1-control valve; 101-valve body; 102-valve core; 103-connecting rod; 104-float; 105-vent; 106-limit block; 2-outer container; 3-two-phase flow inlet pipe; 4-gas phase outlet pipe; 5-liquid phase outlet pipe; 6-throttling mechanism; 7-gas-liquid separation device; 8-evaporator; 9-liquid separator; 10-compressor; 11-condenser. DETAILED DESCRIPTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment.

[0017] First, it should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. For example, although the gas-liquid separation device of the present invention is described in conjunction with a heat pump air conditioning system, this is not limiting, and other equipment with gas-liquid separation requirements can be configured with the gas-liquid separation device of the present invention.

[0018] Figure 1 It is a schematic diagram of the structure of the gas-liquid separation device. Figure 1 As shown, the gas-liquid separation device comprises a control valve 1, an outer container 2, a two-phase flow inlet pipe 3, a gas phase outlet pipe 4, and a liquid phase outlet pipe 5. The control valve 1 is placed above the inner part of the outer container 2 constituting the gas-liquid separation device, the top of the upper connecting channel of the control valve 1 is connected to the gas phase outlet pipe 4, the gas phase outlet pipe 4 is placed at the upper side end of the outer container 2, and the liquid phase outlet pipe 5 is placed at the bottom of the outer container 2; The control valve 1 comprises a valve body 101, a valve core 102, a connecting rod 103, a float 104, a vent 105, and a stop block 106. An installation cavity and two connecting channels are provided inside the valve body 101. A sealing surface is provided on the inner wall of the installation cavity. A valve core 102 for use is provided in the installation cavity. The truncated cone surface of the valve core 102 is closely matched with the sealing surface of the installation cavity. The valve core 102 is connected to the top of the connecting rod 103, and the float 104 is connected to the bottom of the connecting rod 103. The valve core 102, the connecting rod 103 and the float 104 form a rigid component, which can slide freely up and down in the lower connecting channel. A stop block 106 is provided at the bottom of the valve body 101 to limit the valve core 102 and prevent it from falling off from the inside of the valve body. A through vent 105 is provided in the installation cavity or the lower connecting channel of the valve body 101. When the gas-liquid separation device is working, the gas-liquid two-phase flow is introduced through the two-phase flow inlet pipe 3, the gas phase fluid is discharged from the gas phase outlet pipe 4 through the control valve, and the liquid phase fluid is discharged from the liquid phase outlet pipe 5.

[0019] In some embodiments, the vent hole 105 may be one or more. When multiple vent holes are provided, they may be arranged at a certain interval in the vertical direction, and the total flow area of ​​the vent holes is equal to the cross-sectional area of ​​the connecting channel on the upper part of the valve body.

[0020] In some embodiments, the float 104 may adopt a closed thin shell hollow structure or a lightweight anti-liquid absorption material. The maximum buoyancy provided by the float 104 is greater than the overall gravity of the rigid component, ensuring that the valve core is at the highest position and fits tightly with the sealing surface under high liquid level conditions.

[0021] In some embodiments, the valve core 102 and the connecting rod 103 are integrated or split, and the split is connected by threaded connection; The connecting rod 103 and the float 104 are connected by threads, and the valve body 101 and the limit block 106 are connected by threads.

[0022] The control valve of the gas-liquid separation device includes three states: fully closed state, partially open state, and fully open state; Figure 2 The left picture shows the control valve of the gas-liquid separation device in a fully closed state. Figure 2 The middle figure shows the control valve of the gas-liquid separation device in a partially open state. Figure 2 The figure on the right shows the control valve of the gas-liquid separation device in a fully open state. Figure 2 As shown, the position of the valve core of the gas-liquid separation device is automatically adjusted according to the liquid level. Take the initial liquid-free state analysis inside the gas-liquid separation device as an example: In the initial state, the rigid component causes the valve core to be located at the bottom of the lower connecting channel of the valve body under the action of gravity. At this time, the connecting cross-sectional area between the vent hole and the upper connecting channel is the largest; The gas-liquid two-phase fluid flows into the gas-liquid separation device from the two-phase flow inlet pipe, the liquid phase fluid gathers at the bottom under the action of gravity and is discharged from the liquid phase outlet pipe, and the gas phase fluid passes through the vent hole and is discharged from the gas phase outlet pipe at the top; Gradually, the liquid phase is enriched at the bottom, the liquid level rises, and the float is partially submerged; after the buoyancy and gravity are balanced, the float drives the valve core to rise with the liquid level, gradually reducing the valve core opening, and the gas flow begins to decrease; Finally, when the two-phase flow is stable, the valve core satisfies the dynamic balance of liquid phase discharge and gas phase discharge at a certain opening, and the liquid level maintains a stable interface; When the liquid flow suddenly increases significantly, the liquid level increases significantly and completely submerges the float. The buoyancy of the rigid component is greater than the gravity. The valve core is located at the top of the installation cavity and fits tightly with the sealing surface, and the control valve is completely closed.

[0023] The evaporator provided by the present invention is described below. The gas-liquid separation device described below and the gas-liquid separation device described above can be referred to each other.

[0024] The present invention also provides a configuration of a pre-evaporator gas-liquid separation, such as Figure 3 As shown, it includes the above-mentioned gas-liquid separation device, the gas-liquid separation device 7 is arranged on the inlet side of the evaporator 8, the two-phase flow inlet pipe 3 introduces the gas-liquid two-phase flow, the liquid phase outlet pipe 5 is connected to the inlet of the evaporator 8, and the gas phase outlet pipe 4 is connected to the outlet of the evaporator 8.

[0025] The liquid refrigerant flowing from upstream can be reduced in pressure by the throttling mechanism to form a gas-liquid two-phase fluid. The two-phase flow flows into the gas-liquid separation device from the two-phase inlet pipe, and gas-liquid separation is performed in the manner described in the aforementioned embodiment. The liquid fluid flows into the evaporator and is evenly distributed to each channel in the collecting pipe inside the evaporator. The refrigerant flow rate, flow velocity and outlet temperature inside each channel are basically the same, and the heat exchange surface of the evaporator is effectively utilized to the maximum extent; the gas-phase fluid directly converges with the refrigerant at the outlet of the evaporator through the bypass pipe and flows to the downstream components; under the automatic balance of the valve core opening, the pressure drop of the gas phase flow path and the liquid phase flow path remains consistent.

[0026] In some embodiments, such as Figure 4 As shown, a liquid separator 9 is provided between the gas-liquid separation device and the evaporator inlet, and is preferably applied to a multi-channel evaporator without a header, for example, a multi-pass fin-tube evaporator; further, the liquid phase flowing out of the gas-liquid separation device is preferentially evenly distributed by the liquid separator, and then flows into each pass of the evaporator.

[0027] The heat pump air conditioning system provided by the present invention is described below. The evaporator and the gas-liquid separation device described below can correspond to the evaporator and the gas-liquid separation device described above.

[0028] The present invention also provides a heat pump air conditioning system, such as Figure 5 As shown, a heat pump air conditioning system is based on the above-mentioned evaporator, the two-phase flow inlet pipe 3 is connected to the inlet of the throttling mechanism 6, and the outlet of the evaporator 8 is located on the suction side of the compressor 10.

[0029] In some embodiments, the outlet of the evaporator 8 is connected to the inlet of the compressor 10, the outlet of the compressor 10 is connected to the inlet of the condenser 11, and the outlet of the condenser 11 is connected to the inlet of the throttling mechanism 6; The liquid refrigerant is depressurized by the throttling mechanism to form a gas-liquid two-phase fluid, which is separated by the gas-liquid separation device. The liquid phase fluid in the main circuit first passes through the liquid separator and is evenly distributed to the evaporator to absorb heat and vaporize. The gas phase fluid passes through the regulating valve and the gas phase branch to merge with the main refrigerant at the evaporator outlet, then enters the compressor suction port, after being pressurized, flows into the condenser to condense and release heat, and finally flows to the throttling mechanism to complete the entire cycle.

[0030] It is easy for those skilled in the art to understand that the above-mentioned methods can be freely combined and superimposed without conflict.

[0031] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A gas-liquid separation device, characterized in that: The device comprises a control valve (1), an outer container (2), a two-phase flow inlet pipe (3), a gas phase outlet pipe (4), and a liquid phase outlet pipe (5), wherein the control valve (1) is placed above the inner part of the outer container (2) constituting a gas-liquid separation device, the top of the upper connecting channel of the control valve (1) is connected to the gas phase outlet pipe (4), the gas phase outlet pipe (4) is placed at the upper side end of the outer container (2), and the liquid phase outlet pipe (5) is placed at the bottom of the outer container (2); The control valve (1) comprises a valve body (101), a valve core (102), a connecting rod (103), a float (104), a vent (105), and a stop block (106). The valve body (101) is provided with an installation cavity and two connecting channels. A sealing surface is provided on the inner wall of the installation cavity. A valve core (102) for use with the valve core is provided in the installation cavity. The valve core (102) can be closely matched with the sealing surface of the installation cavity. The connecting rod (103) is connected to the valve core (102) at the top and to the float (104) at the bottom. The connecting rod, the valve core and the float together form a rigid component. The rigid component can slide freely up and down in the lower connecting channel. A stop block (106) is provided at the bottom of the valve body (101) to limit the valve core (102) and prevent it from falling off from the inside of the valve body. The installation cavity or the lower connecting channel of the valve body (101) is provided with a through vent (105). When the gas-liquid separation device is in operation, the gas-liquid two-phase flow is introduced through the two-phase flow inlet pipe (3), the gas phase fluid is discharged through the gas phase outlet pipe (4) via the control valve, and the liquid phase fluid is discharged through the liquid phase outlet pipe (5).

2. The gas-liquid separation device according to claim 1, characterized in that: The vent hole (105) may be one, and the flow area of ​​the vent hole is equal to or greater than the cross-sectional area of ​​the connecting channel at the upper part of the valve body.

3. The gas-liquid separation device according to claim 1, characterized in that: There may be a plurality of vent holes (105), which are arranged at a certain interval in the vertical direction, and the total flow area of ​​the vent holes is equal to or greater than the cross-sectional area of ​​the connecting channel at the upper part of the valve body.

4. The gas-liquid separation device according to claim 1, characterized in that: The float (104) may be a closed thin-shell hollow structure or a lightweight anti-liquid absorption material. The maximum buoyancy provided by the float (104) is greater than the overall gravity of the rigid component, ensuring that the valve core is at the highest position and fits tightly against the sealing surface under high liquid level conditions.

5. The gas-liquid separation device according to claim 1, characterized in that: The valve core (102) and the connecting rod (103) are integrated.

6. The gas-liquid separation device according to claim 1, characterized in that: The valve core (102) and the connecting rod (103) are of a split type, and the split type is connected by a threaded connection; The connecting rod (103) and the float (104) are connected by threads, and the valve body (101) and the limit block (106) are connected by threads.

7. The gas-liquid separation device according to any one of claims 1 to 6, characterized in that: The position of the valve core (102) is automatically adjusted according to the liquid level, including: a fully open mode, a fully closed mode, and a partially open mode; Wherein, in the fully open mode, when the liquid level is low, the rigid component is under the action of gravity, the valve core (102) is located at the lowest end of the lower connecting channel of the valve body, and the connecting area of ​​the vent hole is the largest; In the fully closed mode, when the liquid level is high, the rigid component is acted upon by buoyancy, the valve core (102) is located at the top of the installation cavity and fits tightly with the sealing surface, and the connection area of ​​the vent hole is zero; In the partially open mode, when the liquid level is moderate, the rigid component is acted upon by buoyancy so that the valve core (102) is partially located inside the installation cavity, and a portion of the vent hole is connected.

8. A configuration of pre-evaporator gas-liquid separation, characterized in that: The invention comprises a gas-liquid separation device as described in any one of claims 1 to 7, wherein the gas-liquid separation device (7) is arranged at the inlet side of the evaporator (8), the two-phase flow inlet pipe (3) introduces the gas-liquid two-phase flow, the liquid phase outlet pipe (5) is connected to the inlet of the evaporator (8), and the gas phase outlet pipe (4) is connected to the outlet of the evaporator (8).

9. The configuration of the pre-evaporator gas-liquid separation according to claim 8, characterized in that: The liquid phase outlet pipe (5) of the gas-liquid separation device (7) is connected to the inlet of the liquid separator (9), and the outlet of the liquid separator (9) is connected to the inlet of the evaporator (8).

10. A heat pump air conditioning system, characterized in that: An evaporator pre-gas-liquid separation configuration as described in any one of claims 8 or 9 is adopted, the two-phase flow inlet pipe (3) is connected to the inlet of the throttling mechanism (6), and the outlet of the evaporator (8) is located on the suction side of the compressor (10).

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