Integrated electronic expansion valve assembly having gas-liquid separation function of vapor injection heat pump

Abstract

The present invention relates to an integrated electronic expansion valve assembly having a gas-liquid separation function of a steam injection heat pump, the integrated electronic expansion valve assembly being used generally in normal mode, and switching and using in a mode that injects vapor into a compressor when heating efficiency is reduced, thereby allowing the efficiency of the heat pump to be improved.

Description

Integrated electronic expansion valve assembly with vapor-liquid separation function for steam injection heat pump

[0001] The present invention relates to an integrated electronic expansion valve assembly having a vapor-liquid separation function of a steam injection heat pump capable of improving the efficiency of the heat pump.

[0002] [Acknowledgement] This project (result) is the result of the research of the 3rd phase Industry-Academia-Research Cooperation Leading University Development Project (LINC 3.0), which was carried out with funding from the Ministry of Education and the National Research Foundation of Korea.

[0003] (English: Following are results of a study on the "Leaders in Industry-university Cooperation 3.0" Project, supported by the Ministry of Education and National Research Foundation of Korea)

[0004]

[0005] Typically, battery-powered electric vehicles have shorter driving ranges than conventional gasoline-powered vehicles. This problem can become even more pronounced in winter, when electric energy consumption for heating increases.

[0006] To overcome this, it is important to use high-efficiency heating devices in electric vehicles, and heat pumps, which show higher efficiency than electric heating devices, are evaluated as a suitable heating method for electric vehicles.

[0007] While the above heat pump offers significant energy efficiency advantages, it suffers from a significant drop in heating performance when the outside temperature drops. In particular, heating efficiency begins to decline from an outside temperature of 5°C, and a capacity loss of approximately 40% has been reported at -15°C.

[0008] Specifically, while heat pump compressors have a fixed stroke volume, the gaseous refrigerant sucked into the compressor has a characteristic that its specific volume increases significantly at low temperatures. Consequently, the amount of refrigerant transported by the compressor decreases in winter, potentially leading to insufficient heating capacity.

[0009] In addition, when applying a variable capacity compressor, the heating capacity can be improved by securing mass flow rate, but there is a problem in that the reliability of the compressor is reduced as the compression ratio increases excessively as the rotational speed increases and the compressor discharge temperature increases significantly.

[0010] To alleviate the heating capacity shortage that arises when using heat pumps, various improvement measures have been proposed, and steam injection technology is one such method. Steam injection technology can improve both heat pump performance and reliability by reducing compressor discharge temperature and increasing mass flow rate.

[0011] Steam injection technologies currently being actively researched can be broadly divided into methods using flash tanks and methods using internal heat exchangers.

[0012] The vapor injection method through the above flash tank is a method of passing the liquid refrigerant from the condenser outlet through the flash tank to separate it into liquid and gas phases and then injecting it into the compressor.

[0013] The above-mentioned vapor injection method using an internal heat exchanger involves injecting a two-phase refrigerant bypassed from the condenser outlet into a gaseous refrigerant through mutual heat exchange with a high-temperature liquid refrigerant. This method offers excellent reliability because it facilitates securing superheated gaseous refrigerant, but it also increases costs.

[0014] On the other hand, the vapor injection method using the flash tank is relatively economically advantageous due to its simple application of a pressure vessel, but requires a clear solution for injection flow control. Ideally, the liquid and vapor separated in the flash tank should remain in a single-phase state as they exit the flash tank.

[0015] However, if the vapor refrigerant from the flash tank mixes with a large amount of liquid, the vapor injected into the compressor may actually be two-phase. This can lead to problems that reduce compressor reliability. Consequently, the flash tank must be designed to achieve high separation efficiency, such as by installing a liquid level sensor to measure the liquid level for electronic expansion valve control to prevent two-phase refrigerant from being injected into the compressor.

[0016]

[0017] The present invention is intended to solve the above-described problem, and the purpose of the present invention is to provide an integrated electronic expansion valve assembly having a vapor-liquid separation function of a steam injection heat pump that can improve the efficiency of the heat pump by using it in a normal mode during normal times and switching to a mode for injecting steam into the compressor when heating efficiency decreases.

[0018]

[0019] An integrated electronic expansion valve assembly having a gas-liquid separation function of a steam injection heat pump according to the present invention for achieving the above-described purpose is provided.

[0020] A main body having an inlet and an outlet, and a first expansion valve for primarily expanding refrigerant flowing into the interior through the inlet; a gas-liquid separator having a gaseous refrigerant outlet and a liquid refrigerant outlet so that the refrigerant primarily expanded through the first expansion valve can be separated into a gaseous phase and a liquid phase and then discharged separately; a first flow path connecting the liquid refrigerant outlet and the outlet and having a second expansion valve for secondarily expanding refrigerant discharged through the liquid refrigerant outlet, and a flow path branching section having a second flow path spaced apart from one side of the first flow path and connecting the liquid refrigerant outlet and the outlet; It may include a flow path switching unit having an ON / OFF valve installed to be reciprocally movable along a direction intersecting the first and second flow paths and opening one of the first and second flow paths, a check valve connected to an end where the first and second flow paths are joined and a third flow path to open and close the gaseous refrigerant outlet while operating forward and backward in conjunction with the alternate opening of the first and second flow paths; and a control unit that controls the flow path switching unit.

[0021] In this case, the above-mentioned gas-liquid separation unit may use a cyclone gas-liquid separator.

[0022] In addition, the ON / OFF valve may include a fixed pipe body arranged along a direction intersecting the first and second flow paths and having a first through-hole communicating with the first flow path and a second through-hole communicating with the second flow path; a needle valve having at least one through-hole coupled to the inside of the fixed pipe body so as to be movable forward and backward along an axis direction, such that when moving forward, the tip closes the first through-hole and simultaneously opens the second through-hole, and when moving backward, the tip opens the first through-hole and simultaneously closes the second through-hole; and an actuator that operates the needle valve forward and backward.

[0023] In addition, the second expansion valve may include a valve configured to move refrigerant through an orifice formed axially in a partition wall dividing the inside of the fixed pipe body, thereby causing a pressure drop within the third passage.

[0024] In addition, the check valve may include a valve that moves backwards due to a pressure difference between the gas-liquid separator and the third flow path when the first flow path is opened, thereby opening the gas-liquid refrigerant outlet, and a valve that moves forward due to an elastic restoring force of a spring when a pressure balance is achieved between the gas-liquid separator and the third flow path.

[0025] In addition, the control unit may include controlling the flow conversion unit based on a detection signal of a pressure and temperature sensor installed in at least one of the inlet and outlet or external data.

[0026] In addition, refrigerant that has passed through the compressor and condenser is introduced into the inlet, and liquid refrigerant discharged through the outlet can move to the compressor through the evaporator.

[0027] Additionally, the vapor-phase refrigerant discharged through the vapor-phase refrigerant outlet can be injected into the compressor.

[0028] In addition, the above integrated electronic expansion valve assembly can be applied to any one of an electric vehicle, an internal combustion engine vehicle, construction equipment, and a tractor.

[0029]

[0030] The integrated electronic expansion valve assembly having a vapor-liquid separation function of the steam injection heat pump according to the present invention having the above configuration can be used in a normal mode during normal times, and when heating efficiency decreases, it switches to a vapor injection mode and injects the vapor refrigerant discharged through the vapor refrigerant outlet after undergoing a vapor-liquid separation process through a vapor-liquid separation unit into the compressor, thereby improving the efficiency of the heat pump.

[0031]

[0032] Figure 1 is a diagram showing the overall configuration of a heat pump system to which an integrated electronic expansion valve assembly according to the present invention is applied.

[0033] Figure 2 is a perspective view of an integrated electronic expansion valve assembly according to the present invention;

[0034] Figure 3 is a cross-sectional perspective view showing the internal structure of an integrated electronic expansion valve assembly according to the present invention.

[0035] Figure 4 is an exploded perspective view of an ON / OFF valve according to the present invention;

[0036] Figures 5 and 6 are operation status diagrams of the ON / OFF valve according to the present invention.

[0037] Figure 7 is a drawing showing the vapor injection mode of the integrated electronic expansion valve assembly according to the present invention.

[0038] FIG. 8 is a drawing showing the normal mode of the integrated electronic expansion valve assembly according to the present invention.

[0039]

[0040] ※Explanation of symbols※

[0041] 1: Integrated electronic expansion valve assembly 10: Compressor

[0042] 20: Condenser 30: Evaporator

[0043] 100: Main body 101: Inlet

[0044] 103: Outlet 110: First expansion valve

[0045] 120: Pressure and temperature sensor 200: Gas-liquid separator

[0046] 210: Gaseous refrigerant outlet 220: Liquid refrigerant outlet

[0047] 300: Euro branch 310: First Euro

[0048] 320: Second expansion valve 321: Bulkhead

[0049] 323: Orifice 330: Second Euro

[0050] 340: Third Euro 400: Euro Convertible

[0051] 410: ON / OFF valve 411: Fixed pipe

[0052] 411a: First through hole 411b: Second through hole

[0053] 413: Needle valve 413a: Through hole

[0054] 415: Actuator 420: Check valve

[0055] 421: Spring

[0056]

[0057] The configuration and operation of a specific embodiment of the present invention will be described in detail with reference to the attached drawings.

[0058] Here, when adding reference signs to components of each drawing, it should be noted that identical components are indicated with the same signs as much as possible even if they are shown in different drawings.

[0059] Fig. 1 is a diagram showing the overall configuration of a heat pump system to which an integrated electronic expansion valve assembly according to the present invention is applied, and Fig. 2 is a perspective view of an integrated electronic expansion valve assembly according to the present invention.

[0060] Referring to FIGS. 1 and 2, an integrated electronic expansion valve assembly (1) according to a preferred embodiment of the present invention may include a main body (100), a gas-liquid separation unit (200), a flow branch unit (300), a flow conversion unit (400), and a control unit (not shown).

[0061] The composition of the present invention is described in detail as follows.

[0062]

[0063] First, the main body (100) forms the main body of the expansion valve assembly (1), and an inlet (101) may be provided at the upper part of the main body (100) so that refrigerant passing through the compressor (10) and condenser (20) can be introduced.

[0064] And, inside the main body (100), a first expansion valve (110) may be provided to primarily expand the refrigerant flowing into the inside through the inlet (101).

[0065] In addition, a discharge port (103) may be provided at the lower part of the main body (100) through which liquid refrigerant that has passed through a predetermined process is discharged toward the evaporator (30).

[0066] In this case, the refrigerant used in the present invention can be an environmentally friendly refrigerant (R744, R290, mixed refrigerant).

[0067]

[0068] The above-mentioned gas-liquid separator (200) is configured to separate the refrigerant expanded through the first expansion valve (110) into gas phase and liquid phase and then discharge them separately. The gas-liquid separator (200) may be provided with a gas phase refrigerant outlet (210) on the upper side and a liquid phase refrigerant outlet (220) on the lower side.

[0069] Preferably, in the present invention, the gas-liquid separator (200) may use a cyclone gas-liquid separator that separates the refrigerant into gas phase and liquid phase using centrifugal force.

[0070] This gas-liquid separation unit (200) is not operated constantly, but can be used selectively by switching modes as needed during operation of the heat pump.

[0071]

[0072] Referring to FIG. 3, the euro branch unit (300) can be configured with a first euro (310) and a second euro (330) so that it can be used by switching between at least two modes, for example, a normal mode and a vapor injection mode, with one integrated electronic expansion valve assembly (1).

[0073] Specifically, the first flow path (310) can connect the liquid refrigerant outlet (220) and the discharge port (103) of the gas-liquid separator (200), and the first flow path (310) can be equipped with a second expansion valve (320) having an orifice (323) structure that secondarily expands the refrigerant discharged through the liquid refrigerant outlet (220).

[0074] And the second flow path (330) is spaced apart from one side of the first flow path (310), so that the liquid refrigerant outlet (220) and the discharge port (103) can be directly connected via the second flow path (330). The specific roles of the first and second flow paths (310) (330) will be described together in the flow path conversion unit (400) described later.

[0075]

[0076] The above-mentioned euro conversion unit (400) can selectively open either the first euro (310) or the second euro (330) as needed.

[0077] Specifically, the above-described euro conversion unit (400) may include an ON / OFF valve (410) that is installed to be reciprocally movable along a direction intersecting the first and second euros (310)(330) and opens either of the first and second euros (310)(330), and a check valve (420) that is connected to the end (near the outlet (103)) where the first and second euros (310)(330) are joined via the third euro (340) and operates forward and backward when the first and second euros (310)(330) are alternately opened to open and close the gaseous refrigerant outlet (210) of the gas-liquid separator (200).

[0078] Referring to FIG. 4, the ON / OFF valve (410) is provided with a fixed pipe body (411) arranged along a direction intersecting the first and second flow paths (310) (330) and having a first through hole (411a) communicating with the first flow path (310) and a second through hole (411b) communicating with the second flow path (330), and a needle valve (413) provided with at least one through hole (413a) that is coupled to the fixed pipe body (411) so as to be able to move forward and backward along the axial direction so that when moving forward, the tip closes the first through hole (411a) and opens the second through hole (411b) at the same time (see FIG. 5), and when moving backward, the tip opens the first through hole (411a) and closes the second through hole (411b) at the same time (see FIG. 6), and the needle valve (413) An actuator (415) (see Fig. 3) for moving forward and backward may be provided.

[0079] Referring to Fig. 6, the second expansion valve (320) may be configured through an orifice (323) structure formed axially in a partition wall (321) that partitions the inside of the fixed pipe (411). This second expansion valve (320) may cause a pressure drop within the third flow path (340) by moving the refrigerant through the orifice (323).

[0080] Referring to Fig. 7, when the first passage (310) is opened, the pressure difference between the inside of the gas-liquid separator (200) and the third passage (340) causes the check valve (420) to move backward, thereby opening the gaseous refrigerant outlet (210). When the gaseous refrigerant outlet (210) is opened, the gaseous refrigerant separated through the gas-liquid separator (200) can be injected into the compressor (10) (steam injection mode).

[0081] Referring to Fig. 8, when the second passage (330) is opened, the pressure balance between the gas-liquid separator (200) and the third passage (340) is achieved, and the check valve (420) can be moved forward by the elastic restoring force of the spring (421) to close the gas-liquid refrigerant outlet (210). When the gas-liquid refrigerant outlet (210) is closed, gas-liquid separation does not occur through the gas-liquid separator (200), and the liquid refrigerant flowing into the gas-liquid separator (200) can be discharged toward the evaporator (30) through the liquid refrigerant outlet (220) and the discharge port (103) on the lower side (normal mode).

[0082]

[0083] The above control unit can control the ON / OFF valve (410) of the flow switching unit (400) so as to set the electronic expansion valve assembly (1) according to the present invention to either the normal mode or the vapor injection mode.

[0084] This control unit can control the flow conversion unit (400) based on a detection signal of a pressure and temperature sensor (120) installed in at least one of the inlet (101) and outlet (103) of the main body (100) or external data.

[0085]

[0086] The present invention, having a configuration as described above, can selectively use either the normal mode (see FIG. 8) or the vapor injection mode (see FIG. 7) using one integrated electronic expansion valve assembly (1).

[0087] That is, the above integrated electronic expansion valve assembly (1) is used in normal mode during normal times, and when heating efficiency decreases, it switches to steam injection mode and injects the refrigerant in the gas phase discharged through the gas-liquid outlet (210) after undergoing a gas-liquid separation process through the gas-liquid separator (200) into the compressor (10), thereby improving the efficiency of the heat pump.

[0088] An integrated electronic expansion valve assembly (1) like this can be applied and used in electric vehicles as well as internal combustion engine vehicles, construction equipment, tractors, etc.

[0089]

[0090] Although the present invention has been described and illustrated with specific embodiments above, the present invention is not limited to the above-described embodiments, and various changes and modifications are possible within a scope that does not depart from the technical spirit of the present invention.

Claims

1. A main body having an inlet and an outlet, and a first expansion valve for initially expanding refrigerant flowing into the interior through the inlet; A gas-liquid separation unit having a gas-phase refrigerant outlet and a liquid-phase refrigerant outlet so that the refrigerant expanded for the first time through the first expansion valve can be separated into gas and liquid phases and then discharged separately; A flow path branch section including a first flow path that connects the liquid refrigerant outlet and the discharge port and has a second expansion valve that secondarily expands the refrigerant discharged through the liquid refrigerant outlet, and a second flow path that is spaced apart from one side of the first flow path and connects the liquid refrigerant outlet and the discharge port; A flow path switching unit having an ON / OFF valve that is installed to be reciprocally movable along the direction intersecting the first and second flow paths and opens one of the first and second flow paths, and a check valve that is connected to the end where the first and second flow paths are joined and the third flow path through the middle and operates forward and backward in conjunction with the alternate opening of the first and second flow paths to open and close the gaseous refrigerant outlet; and An integrated electronic expansion valve assembly comprising a control unit for controlling the above-mentioned euro conversion unit.

2. In paragraph 1, The above gas-liquid separation unit is, An integrated electronic expansion valve assembly using a cyclone vapor-liquid separator.

3. In paragraph 1, The above ON / OFF valve, A fixed pipe body arranged along a direction intersecting the first and second euros, and having a first through-hole communicating with the first euro and a second through-hole communicating with the second euro; A needle valve having at least one through hole that is coupled to the inside of the fixed body so as to be able to move forward and backward along the axis, so that when moving forward, the tip can close the first through hole and open the second through hole at the same time, and when moving backward, the tip can open the first through hole and close the second through hole at the same time; and An integrated electronic expansion valve assembly including an actuator for moving the needle valve forward and backward.

4. In paragraph 3, The above second expansion valve, An integrated electronic expansion valve assembly including a refrigerant moving through an orifice formed axially in a bulkhead dividing the inside of the fixed pipe to cause a pressure drop within the third passage.

5. In paragraph 3, The above check valve, When the first flow path is opened, the gaseous refrigerant outlet is opened while moving backward due to the pressure difference between the gas-liquid separator and the third flow path. An integrated electronic expansion valve assembly, wherein when the second passage is opened, the pressure of the gas-liquid separator and the third passage are balanced, and the check valve is moved forward by the elastic restoring force of the spring, thereby closing the gas-phase refrigerant outlet.

6. In paragraph 1, The above control unit, An integrated electronic expansion valve assembly comprising controlling the flow switching unit based on a detection signal from a pressure and temperature sensor installed in at least one of the inlet and outlet or external data.

7. In paragraph 1, Refrigerant that has passed through the compressor and condenser flows into the above inlet. An integrated electronic expansion valve assembly in which the liquid refrigerant discharged through the above outlet moves to the compressor through the evaporator.

8. In paragraph 7, The vapor-phase refrigerant discharged through the above vapor-phase refrigerant outlet is An integrated electronic expansion valve assembly which is injected into the above compressor.

9. In paragraph 1, The above integrated electronic expansion valve assembly comprises: An integrated electronic expansion valve assembly applicable to any one of an electric vehicle, an internal combustion engine vehicle, a construction machine, and a tractor.

Images