JP2012220140A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive expansion valve for distributing a refrigerant to two evaporators.SOLUTION: In the expansion valve, a branched refrigerant path formed of a first refrigerant path 23 and a second refrigerant path 24 is provided on the downstream side of a valve 3a for adiabatically expanding a liquid refrigerant. Each refrigerant path is provided with a first throttle member 25 and a second throttle member 26. The first throttle member 25 and the second throttle member 26 have a very simple constitution with openings 25a, 26a formed at the center of a disk plate, thereby reducing the manufacturing cost of the expansion valve. A flow rate ratio of the refrigerant to be supplied to the two evaporators is decided by an area ratio between the openings 25a, 26a of the first throttle member 25 and the second throttle member 26.

Description

  The present invention relates to an expansion valve, and in particular, in a refrigeration cycle of an automotive air conditioner system, the refrigerant at the evaporator outlet maintains a predetermined degree of superheat with respect to the flow rate of the vapor refrigerant fed into the evaporator while adiabatic expansion of the liquid refrigerant into a low-temperature and low-pressure vapor refrigerant. The present invention relates to an expansion valve that controls the operation.

  In an automotive air conditioner system, a compressor that compresses refrigerant, a condenser that condenses the refrigerant, a receiver that separates the gas-liquid mixed refrigerant, an expansion valve that adiabatically expands the refrigerant, and an evaporator that evaporates the refrigerant are annularly piped. The refrigeration cycle is configured. As an expansion valve for expanding the refrigerant, a temperature expansion valve is generally used in which the flow rate of the refrigerant supplied to the evaporator is controlled according to the temperature and pressure of the refrigerant at the evaporator outlet.

  The evaporator that exchanges heat with the air in the vehicle interior is required to be compact because it is installed in the vehicle interior. For this reason, an evaporator is generally used in which two heat exchangers that are thinned in a direction that allows air to pass therethrough are stacked and the refrigerant is allowed to flow in series.

  In such an evaporator, as the heat exchanger becomes thinner, the internal passage through which the refrigerant passes becomes narrower, and the passage is connected in series by two heat exchangers and becomes longer. For this reason, the evaporator configured as described above has a large pressure loss in the passage through which the refrigerant passes, and the efficiency of the refrigeration cycle is reduced accordingly.

  On the other hand, an evaporator having a configuration in which two heat exchangers are made independent and a refrigerant is supplied to each heat exchanger in parallel has been proposed (see, for example, Patent Documents 1 and 2). According to this evaporator, the pressure loss when the refrigerant passes through the heat exchanger is reduced, the net loss when the refrigeration cycle is viewed as a whole is reduced, and the cooling power can be improved.

  Patent Documents 1 and 2 also propose an expansion valve used for such an evaporator. According to this expansion valve, it has two valves that can adiabatically expand the refrigerant independently, and the two valves are linked and controlled according to the temperature and pressure of the refrigerant exiting the heat exchanger and joining the evaporator. The structure to perform is disclosed.

JP 2010-38455 A, FIGS. 5 and 6 International Publication No. WO2010 / 131918, FIGS. 4 and 7

  However, each of the disclosed expansion valves includes two or more valves and a throttle, and distributes and supplies the expanded refrigerant to two heat exchangers arranged in parallel. There was a problem that the manufacturing cost was complicated.

  The present invention has been made in view of such a point, and an object thereof is to provide an expansion valve capable of distributing and supplying a refrigerant with a simple configuration.

  In the present invention, in order to solve the above-described problem, a valve portion that expands liquid refrigerant to form vapor refrigerant, a power element that detects the temperature and pressure of the evaporated refrigerant and controls the opening degree of the valve portion, And a plurality of refrigerant passages that are branched from the downstream of the valve portion and communicated with a plurality of low-pressure outlet ports, respectively, and are arranged in each of the refrigerant passages to achieve a refrigerant flow rate ratio. There is provided an expansion valve comprising a throttle passage having an opening of a corresponding area.

  According to such an expansion valve, when the vapor refrigerant adiabatically expanded in the valve portion passes through the throttle passage of the refrigerant passage, it is distributed at a flow rate ratio according to the area of the opening portion, and is stable to the evaporator. Can be supplied at a distributed ratio.

  The expansion valve configured as described above has an advantage that the manufacturing cost can be reduced because the distribution of the vapor refrigerant is performed by the throttle passage having a simple structure arranged in the refrigerant passage. In addition, this expansion valve can supply the adiabatically expanded vapor refrigerant in a stable distribution ratio in parallel to the plurality of heat exchangers of the evaporator, thereby reducing the pressure loss in the evaporator and optimizing the amount of heat exchange in the evaporator, The cooling efficiency of the applied refrigeration cycle can be improved.

It is a figure which shows the refrigerating cycle to which the expansion valve of this invention is applied. It is a center longitudinal cross-sectional view of the expansion valve which concerns on 1st Embodiment. It is the center longitudinal cross-sectional view of the expansion valve which concerns on 1st Embodiment seen from the surface of the orthogonal | vertical direction with respect to the surface of FIG. It is a center longitudinal cross-sectional view of the expansion valve which concerns on 2nd Embodiment. It is the center longitudinal cross-sectional view of the expansion valve which concerns on 2nd Embodiment seen from the surface of the orthogonal | vertical direction with respect to the surface of FIG. It is a center longitudinal cross-sectional view of the expansion valve which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a refrigeration cycle to which an expansion valve of the present invention is applied.
The refrigeration cycle of an automotive air conditioner system is configured by annularly connecting a compressor 1, a condenser 2, an expansion valve 3, and an evaporator 4. The compressor 1 compresses the circulating refrigerant and sends it to the condenser 2. The condenser 2 is configured such that the outside air is forcibly passed by the cooling fan 5, and condenses the refrigerant that has become high temperature and high pressure by the compressor 1 by heat exchange with the outside air. The outlet of the condenser 2 is provided with a receiver for storing the condensed refrigerant, and the liquid refrigerant separated from the gas and liquid there is supplied to the expansion valve 3.

  The expansion valve 3 is a general temperature type expansion valve provided with a valve portion 3a for adiabatic expansion of liquid refrigerant. The outlet of the expansion valve 3 is configured to distribute and send out the refrigerant adiabatically expanded by the valve portion 3a. Yes. The evaporator 4 includes a first heat exchanger 4 a and a second heat exchanger 4 b that are stacked on the downstream air passage of the fan 6. The first heat exchanger 4a on the fan 6 side and the second heat exchanger 4b on the outlet side are supplied with the vapor refrigerant that is adiabatically expanded by the expansion valve 3 and distributed in two, and is blown by the fan 6. The vapor refrigerant is evaporated by heat exchange with air. The refrigerant that has exited the first heat exchanger 4a and the second heat exchanger 4b is merged, and then returned to the compressor 1 via the expansion valve 3. When the refrigerant returned from the evaporator 4 passes through the expansion valve 3, the expansion valve 3 monitors the temperature and pressure of the return refrigerant, that is, the degree of superheat of the evaporator outlet refrigerant, and the valve unit according to the degree of superheat. The opening degree of 3a is controlled.

  In the evaporator 4, the first heat exchanger 4 a on the fan 6 side performs heat exchange with higher-temperature air, and the second heat exchanger 4 b on the outlet side is replaced by the first heat exchanger 4 a. Heat exchange is performed by the cooled air. For this reason, the expansion valve 3 is set so that the flow rate of the refrigerant sent to the first heat exchanger 4a is larger than the flow rate of the refrigerant sent to the second heat exchanger 4b. In the present embodiment, the expansion valve 3 is vapor refrigerant so that the refrigerant flow ratio between the first heat exchanger 4a on the fan 6 side and the second heat exchanger 4b on the outlet side is 2: 1. To distribute.

2 is a central longitudinal sectional view of the expansion valve according to the first embodiment, and FIG. 3 is a central longitudinal sectional view of the expansion valve according to the first embodiment as viewed in a plane perpendicular to the plane of FIG. FIG.
The expansion valve according to the first embodiment has a rectangular parallelepiped body 11, and a high-pressure inlet port 12 to which a high-pressure liquid refrigerant is supplied is provided below one side surface (right side surface in FIG. 3). It has been. A first low-pressure outlet port 13 and a second low-pressure outlet port 14 are respectively provided below the side surface (left and right side surfaces in FIG. 2) adjacent to the side surface of the body 11 where the high-pressure inlet port 12 is provided. Yes. The first low-pressure outlet port 13 is piped to the first heat exchanger 4 a on the fan 6 side of the evaporator 4, and the second low-pressure outlet port 14 is the second heat exchanger 4 b on the outlet side of the evaporator 4. To be piped. The body 11 is also provided with a return refrigerant inlet port 15 above the side view in which the first low-pressure outlet port 13 is provided, and a return refrigerant outlet above the side view in which the high-pressure inlet port 12 is provided. A port 16 is provided.

  A power element 17 for detecting the degree of superheat of the refrigerant returned from the evaporator 4 is screwed to the upper end surface of the body 11 in the figure. In the body 11 directly below the power element 17, a shaft 18, a valve portion 3a, a compression coil spring 19, and an adjusting screw 20 are arranged coaxially.

  The valve portion 3 a includes a ball-shaped valve body 21 and a valve seat 22 formed on the body 11, and a valve hole is formed in the valve seat 22. The downstream side of the valve portion 3a is bifurcated into a first refrigerant passage 23 and a second refrigerant passage 24, and communicates with the first low-pressure outlet port 13 and the second low-pressure outlet port 14, respectively.

  The first refrigerant passage 23 is arranged at a boundary portion with the first low-pressure outlet port 13 by fitting a first throttle member 25 to constitute a first throttle passage. Further, the second refrigerant passage 24 is arranged at a boundary portion with the second low-pressure outlet port 14 by fitting a second throttle member 26 to constitute a second throttle passage. The first throttle member 25 and the second throttle member 26 are formed in a ring shape having openings 25a and 26a in the center of the disc, and the openings 25a and 26a have an area corresponding to the refrigerant flow rate ratio. It is open. That is, in the present embodiment, the ratio of the flow rate of the first throttle member 25 and the flow rate of the second throttle member 26 is 2: 1, so the opening 25a of the first throttle member 25 and the second flow rate The area ratio of the second aperture member 26 to the opening 26a is 2: 1.

  The valve body 21 of the valve portion 3 a is disposed in a valve chamber communicating with the high-pressure inlet port 12 so as to be able to contact with and separate from the valve seat 22, and is closed by a compression coil spring 19 via a support member 27. Energized in the valve direction.

  The compression coil spring 19 is received by an adjustment screw 20 screwed to the body 11, and the load of the compression coil spring 19 is adjusted by adjusting the screwing amount of the adjustment screw 20. This adjustment corresponds to the setting of the degree of superheat that the expansion valve is to control. A threaded portion of the adjusting screw 20 to the body 11 is hermetically sealed by an O-ring 28.

  The power element 17 is screwed into a mounting hole formed in the upper surface of the body 11 in the figure. The mounting hole of the power element 17 communicates with the refrigerant return passage 29 formed between the return refrigerant inlet port 15 and the return refrigerant outlet port 16, and introduces the refrigerant passing through the refrigerant return passage 29 into the power element 17. I can do it.

  The power element 17 is formed by sandwiching the diaphragm 30 between the upper housing 31 and the lower housing 32 and welding the outer periphery thereof together. A sealed space surrounded by the diaphragm 30 and the upper housing 31 is filled with a gas having characteristics similar to that of a refrigerant, and constitutes a greenhouse. The lower housing 32 is provided with a disk 33 for transmitting the displacement of the diaphragm 30 to the valve body 21 of the valve portion 3a. The disk 33 is fitted to the upper end of the shaft 18 held by the holder 34 and is centered by the shaft 18 in the lower housing 32.

  The upper portion of the holder 34 is installed in the mounting hole of the power element 17, and a compression coil spring 35 is accommodated in the upper portion so as to apply a lateral load to the shaft 18, as shown in FIG. Yes. Since the axial movement of the shaft 18 is restricted by a lateral load applied by the compression coil spring 35, the valve element 21 can be used even if the liquid refrigerant introduced into the high-pressure inlet port 12 undergoes pressure fluctuation. Is prevented from vibrating in the axial direction and generating abnormal noise. The holder 34 also hangs down through the refrigerant return passage 29, and a lower end portion of the holder 34 surrounds the shaft 18 between the first refrigerant passage 23 and the second refrigerant passage 24 and the refrigerant return passage 29. The provided O-ring 36 is pressed. The O-ring 36 prevents the refrigerant from leaking from the first refrigerant passage 23 and the second refrigerant passage 24 to the refrigerant return passage 29 without going to the evaporator 4.

  According to the expansion valve having the above configuration, when the compressor 1 is stopped or operating at the minimum capacity, the pressure of the refrigerant return passage 29 is high, and the diaphragm 30 is sensed by the power element 17 that senses this pressure. It is displaced to the greenhouse side. Thereby, since the valve body 21 is urged | biased by the compression coil spring 19 in the valve closing direction, and is seated on the valve seat 22, the valve part 3a is a valve closing state.

  When the compressor 1 starts to compress the refrigerant, the pressure in the refrigerant return passage 29 decreases, and the diaphragm 30 of the power element 17 is displaced toward the valve portion 3a. The high-pressure inlet port 12 receives high-pressure refrigerant. Will be introduced. Eventually, the valve portion 3 a is opened by the power element 17, and the liquid refrigerant condensed by the condenser 2 is introduced into the high-pressure inlet port 12. The liquid refrigerant introduced into the valve chamber is adiabatically expanded by the valve portion 3 a to become a low-temperature / low-pressure vapor refrigerant and flows into the first refrigerant passage 23 and the second refrigerant passage 24. The vapor refrigerant that has flowed into the first refrigerant passage 23 passes through the first throttle member 25 and is sent from the first low-pressure outlet port 13 to the first heat exchanger 4 a of the evaporator 4. The vapor refrigerant flowing into the second refrigerant passage 24 passes through the second throttle member 26 and is sent from the second low-pressure outlet port 14 to the second heat exchanger 4 b of the evaporator 4. When the vapor refrigerant passes through the first throttle member 25 and the second throttle member 26, the vapor refrigerant is distributed to the area ratio of the openings 25a and 26a of the first throttle member 25 and the second throttle member 26 to 2: 1. Is done.

  In the evaporator 4, the vapor refrigerant introduced into the first heat exchanger 4 a and the second heat exchanger 4 b is evaporated by heat exchange with the air blown by the fan 6, and then merged to return refrigerant inlet port. Returned to 15. The air that has been blown by the fan 6 and passed through the evaporator 4 is dehumidified and cooled, and is then appropriately adjusted in temperature before being blown into the vehicle interior.

  The refrigerant introduced into the return refrigerant inlet port 15 passes through the refrigerant return passage 29 and is returned to the compressor 1 from the return refrigerant outlet port 16. When the refrigerant from the evaporator 4 passes through the refrigerant return passage 29, the superheat degree of the refrigerant is sensed by the power element 17, and the valve lift of the valve portion 3a is controlled according to the superheat degree. Thereby, the flow rate of the refrigerant is controlled by the valve portion 3a and supplied to the first heat exchanger 4a and the second heat exchanger 4b of the evaporator 4 at a predetermined distribution ratio. Since the valve portion 3a is feedback-controlled by the degree of superheat of the refrigerant at the outlet of the evaporator 4, this expansion valve has the degree of superheat set by the compression coil spring 19 at the flow rate of the vapor refrigerant sent to the evaporator 4. Control to maintain.

  4 is a central longitudinal sectional view of the expansion valve according to the second embodiment, and FIG. 5 is a central longitudinal sectional view of the expansion valve according to the second embodiment viewed in a plane perpendicular to the plane of FIG. FIG. 4 and 5, the same or equivalent components as those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The expansion valve according to the second embodiment changes the mounting position of the second low-pressure outlet port 14 as compared with the expansion valve according to the first embodiment. That is, in this expansion valve, the second low-pressure outlet port 14 is provided on the side surface opposite to the side surface on which the high-pressure inlet port 12 of the body 11 is provided. Therefore, the first low-pressure outlet port 13 and the first refrigerant passage 23 and the second low-pressure outlet port 14 and the second refrigerant passage 24 are similar to the return refrigerant inlet port 15 and the return refrigerant outlet port 16 in the body. 11 is bent in an L-shape.

  The first refrigerant passage 23 and the second refrigerant passage 24 are provided with a first throttle member 25 and a second throttle member 26, and the vapor refrigerant expanded by the valve portion 3 a is the first throttle member 25. And the second throttle member 26, respectively. At this time, the vapor refrigerant flows through the first low pressure outlet port 13 and the second low pressure outlet port at a flow rate ratio determined by the area ratio of the openings 25a and 26a of the first throttle member 25 and the second throttle member 26. 14 is sent to the evaporator 4 in a state where the flow rate is distributed.

  FIG. 6 is a central longitudinal sectional view of an expansion valve according to the third embodiment. In FIG. 6, the same or equivalent components as those shown in FIGS. 4 and 5 are denoted by the same reference numerals, and detailed description thereof is omitted. Further, the expansion valve according to the third embodiment is the same as that of FIG. 4 in the central longitudinal sectional view of the expansion valve according to the third embodiment viewed in a plane perpendicular to the plane of FIG. Therefore, illustration is omitted.

  The expansion valve according to the third embodiment has an expansion valve according to the second embodiment in which a throttle member is disposed only in one of the first refrigerant passage 23 and the second refrigerant passage 24. Compared to manufacturing costs. That is, in the illustrated example, the first throttle member 25 is provided only in the first refrigerant passage 23, and the second refrigerant passage 24 is a passage cut-off substantially equal to the opening area of the opening 26 a of the second throttle member 26. It is formed to have an area. Thereby, in this expansion valve, the refrigerant is distributed at a flow rate ratio similar to that of the expansion valves according to the first and second embodiments, and the first heat exchanger 4a and the second heat exchanger 4b of the evaporator 4 are distributed. To be supplied.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these specific embodiments. For example, in the above embodiment, the expansion valve applied to the evaporator 4 including the two heat exchangers, the first heat exchanger 4a and the second heat exchanger 4b, has been described. However, this expansion valve can include a number of refrigerant passages and throttle members corresponding to the number of heat exchangers of the evaporator 4 to be applied, and each throttle member has an opening having an area corresponding to the refrigerant flow ratio. Will have.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Capacitor 3 Expansion valve 3a Valve part 4 Evaporator 4a 1st heat exchanger 4b 2nd heat exchanger 5 Cooling fan 6 Fan 11 Body 12 High pressure inlet port 13 1st low pressure outlet port 14 2nd low pressure outlet Port 15 Return refrigerant inlet port 16 Return refrigerant outlet port 17 Power element 18 Shaft 19 Compression coil spring 20 Adjustment screw 21 Valve body 22 Valve seat 23 First refrigerant passage 24 Second refrigerant passage 25 First throttle member 25a Opening 26 Second throttle member 26a Opening portion 27 Support member 28 O-ring 29 Refrigerant return passage 30 Diaphragm 31 Upper housing 32 Lower housing 33 Disc 34 Holder 35 Compression coil spring 36 O-ring

Claims (3)

An expansion valve comprising: a valve portion that expands liquid refrigerant to form vapor refrigerant; and a power element that detects the temperature and pressure of the evaporated refrigerant and controls the opening of the valve portion,
A plurality of refrigerant passages branched from downstream of the valve portion and formed to communicate with a plurality of low-pressure outlet ports, respectively;
A throttle passage that is disposed in each of the refrigerant passages and has an opening having an area corresponding to the refrigerant flow rate ratio;
An expansion valve characterized by comprising:   2. The expansion valve according to claim 1, wherein the throttle passage includes a throttle member having the opening at the center of a disc.   The expansion valve according to claim 1, wherein the throttle passage is a passage having the same passage cross-sectional area as the opening.

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