JP2010038454A - Expansion valve and vapor compression refrigerating cycle equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor compression refrigerating cycle and an expansion valve used in the same capable of carrying out stable flow rate distribution, even when a refrigerant flow rate is low. <P>SOLUTION: The expansion valve is used in the refrigerating cycle equipped with an ejector 5, a first evaporator 6, and a second evaporator 7. The expansion valve has an inflow part 31 for receiving a flow of a refrigerant having radiated heat in a radiator 2; an orifice 32 for carrying out throttling expansion of the flowing in refrigerant to provide a gas-liquid two phase refrigerant; a valve element 34 for adjusting the flow rate of the refrigerant passing through the orifice 32; a thermosensitive driving part 52 driving the valve element 34, a dryness distribution forming space 36 provided adjacent to a downstream side of the orifice 32 and forming a dryness distribution of the refrigerant by using inertial force; a first outlet 41, connected to the dryness distribution forming space 36 and sending out the refrigerant to a nozzle part 5a side; and a second outlet 42 connected to the dryness distribution forming space 36 and sending out a refrigerant, with a degree of dryness higher than the refrigerant flowing out from the first outlet 41 to a second evaporator 7 side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an expansion valve and a vapor compression refrigeration cycle including the expansion valve.

As a conventional vapor compression refrigeration cycle, for example, as described in Patent Document 1, a vapor compression refrigeration cycle provided with an ejector as means for reducing the pressure of a refrigerant cooled by a radiator and two evaporators It has been known. In this refrigeration cycle, a compressor, a radiator, an expansion valve, a flow distributor, an ejector, and a first evaporator are connected in a ring shape, and the suction flow path branched by the flow distributor is connected to the ejector. Two evaporators are provided. The ejector includes a nozzle unit that takes in one refrigerant distributed by the flow distributor and decompresses and expands in an isentropic manner, and a suction unit that sucks the other refrigerant distributed by the flow distributor after passing through the second evaporator And. The high-speed refrigerant flow decompressed and expanded at the nozzle part is mixed with the refrigerant sucked from the suction part in the mixing part, further pressurized by the pressure raising part, and then flows out toward the other evaporator. After evaporating, it is sucked into the compressor.
JP 2008-8591 A

  In the refrigeration cycle, the refrigerant is distributed to the nozzle side and the second evaporator side by a flow rate distributor provided downstream of the expansion valve. However, when the refrigerant flow rate is small, the refrigerant flowing out from the expansion valve becomes a separated flow or a slag flow, and thus it is difficult to stably distribute the flow rate by the flow distributor.

  An object of the present invention is to provide a vapor compression refrigeration cycle capable of stable flow distribution even when the refrigerant flow rate is small, and an expansion valve used therefor.

  In order to achieve the above object, the present invention employs the following technical means.

  The invention described in claim 1 includes a compressor (1) that compresses a refrigerant, a radiator (2) that radiates the refrigerant compressed by the compressor (1), and a refrigerant that radiates heat by the radiator (2). A part of the refrigerant is taken in and ejected from the nozzle part (5a) to form a high-speed refrigerant flow, and the ejector (5) that sucks the refrigerant from the suction part (5b) by the refrigerant flow, and the ejector (5 The first evaporator (6) that evaporates the refrigerant that has flowed out from the compressor (1) and the remaining refrigerant out of the refrigerant that has radiated heat from the radiator (2) is evaporated and the suction unit ( 5b) an expansion valve used in a vapor compression refrigeration cycle having a second evaporator (7) that flows out to the side, and an inflow part (31) that allows the refrigerant radiated by the radiator (2) to flow in, Provided on the downstream side of the inflow part (31), restricts the inflowing refrigerant An orifice (32) that is expanded into a gas-liquid two-phase refrigerant, a valve body (34) that adjusts the flow rate of the refrigerant that passes through the orifice (32), and a drive unit (52) that drives the valve body (34). , Provided adjacent to the downstream side of the orifice (32), and connected to a dryness distribution forming space (36) that forms a dryness distribution of the refrigerant by utilizing inertia force, and a dryness distribution forming space (36). The first outlet (41) for allowing the refrigerant to flow out to one of the nozzle part (5a) side or the second evaporator (7) side and the dryness distribution forming space (36) are connected to the first outlet (41 An expansion valve characterized by having a second outlet (42) for allowing the refrigerant having a higher dryness than the refrigerant flowing out from the nozzle section (5a) or the second evaporator (7) to flow out. It is.

  Thereby, in the dryness distribution forming space (36) adjacent to the downstream side of the orifice (32), the refrigerant immediately after being decompressed by the orifice (32) is used as the first outlet (41) and the second outlet (42). Can be distributed. Since the refrigerant immediately after being depressurized by the orifice (32) becomes a mist flow, it becomes easy to form a dryness distribution of the refrigerant using inertial force. For this reason, by varying the dryness of the refrigerant distributed to the first outlet (41) and the second outlet (42), even when the refrigerant flow rate is small, the nozzle (5a) side and the second evaporator (7) Stable flow rate (mass flow rate) distribution can be performed on the side.

  In the invention according to claim 2, the dryness distribution forming space (36) has a cylindrical shape in which the orifice (32) is connected in the tangential direction, and the gas-liquid two-phase refrigerant flowing out from the orifice (32). It is characterized by producing a swirl flow.

  Thereby, in the dryness distribution forming space (36), it is possible to form a dryness distribution in which the dryness becomes lower toward the outer peripheral side of the cylinder due to the difference in inertia force between the liquid-phase refrigerant and the gas-phase refrigerant.

  The invention described in claim 3 is characterized in that the first outlet (41) is connected to the cylinder outer peripheral side of the second outlet (42) in the dryness distribution forming space (36).

  Thereby, a refrigerant | coolant whose dryness is lower than a 2nd outflow port (42) can be distributed with respect to a 1st outflow port (41).

  The invention according to claim 4 is characterized in that the second outlet (42) is connected on the central axis (C1) of the dryness distribution forming space (36).

  Since the dryness is likely to be highest on the central axis (C1) of the dryness distribution forming space (36), a refrigerant having a higher dryness than the first outlet (41) is supplied to the second outlet (42). Can be distributed.

  The invention according to claim 5 is characterized in that the first outlet (43) is connected to the bottom of the dryness distribution forming space (36).

  Since the bottom of the dryness distribution forming space (36) tends to be low in dryness due to gravity settling of the liquid refrigerant, the refrigerant having a lower dryness than the second outlet (42) with respect to the first outlet (43). Can be distributed.

  According to a sixth aspect of the present invention, the dryness distribution forming space (36, 37) has a trap structure (38, 39) formed on the flow path of the refrigerant flowing out from the orifice (32), and the first flow The outlets (41, 43) are characterized in that they are connected below the second outlet (42) in the dryness distribution forming space (36, 37).

  Since liquid phase refrigerant is more susceptible to inertial force than gas phase refrigerant, the liquid phase refrigerant collides with the trap structure (38, 39) and the flow velocity decreases. Thereby, in the dryness distribution forming space (36), the lower the dryness is due to the gravity settling of the liquid refrigerant, the lower the dryness is with respect to the first outlet (41) than the second outlet (42). Low refrigerant can be distributed.

  The invention described in claim 7 is characterized in that it is directly connected to at least one of the first evaporator (6) and the second evaporator (7).

  Thereby, since an expansion valve can be handled as an integrated object with at least one of a 1st evaporator (6) or a 2nd evaporator (7), mounting to a vehicle etc. becomes easy.

  The invention according to claim 8 includes a compressor (1) that compresses refrigerant, a radiator (2) that dissipates heat from the refrigerant compressed by the compressor (1), and a refrigerant that dissipates heat from the radiator (2). A part of the refrigerant is taken in and ejected from the nozzle part (5a) to form a high-speed refrigerant flow, and the ejector (5) that sucks the refrigerant from the suction part (5b) by the refrigerant flow, and the ejector (5 The first evaporator (6) that evaporates the refrigerant that has flowed out from the compressor (1) and the remaining refrigerant out of the refrigerant that has radiated heat from the radiator (2) is evaporated and the suction unit ( 5b) A vapor compression refrigeration cycle comprising the second evaporator (7) flowing out to the side and the expansion valve of the invention.

  Thereby, the same effect as the said invention is acquired in a vapor compression refrigeration cycle.

  In addition, the code | symbol in the bracket | parenthesis of each said means has shown an example of the corresponding relationship with the specific means as described in embodiment mentioned later.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a vapor compression refrigeration cycle of the present embodiment. This vapor compression refrigeration cycle is mounted on a vehicle, and a compressor 1, a radiator 2, a receiver 2a, an expansion valve 3, an ejector 5, and a first evaporator 6 are connected in an annular shape by a refrigerant pipe. At the same time, the capillary 4 and the second evaporator 7 are provided in the suction flow path 9 which is branched in the expansion valve 3 and connected to the ejector 5. The operation of the compressor 1 is controlled by a control device (not shown).

  The compressor 1 is a fluid machine that sucks the refrigerant flowing out from the first evaporator 6, compresses the refrigerant to high temperature and high pressure, and discharges the refrigerant to the radiator 2 side. The compressor 1 is a vehicle travel engine via an electromagnetic clutch and a belt (not shown). It is rotationally driven by. The compressor 1 is, for example, a swash plate type variable displacement compressor in which a discharge capacity is varied by inputting a control signal from a control device to an electromagnetic displacement control valve. In the compressor 1 of the present embodiment, the discharge capacity can be continuously changed from 100% to around 0% by adjusting the pressure in the swash plate chamber. Therefore, the compressor 1 can be substantially stopped by reducing the discharge capacity to around 0%. Therefore, it is good also as a clutchless structure which always connects the rotating shaft of the compressor 1 to a vehicle engine via a pulley and a belt.

  The radiator 2 is a heat exchanger that radiates and cools the high-pressure refrigerant discharged from the compressor 1 by heat exchange with outside air that is forcibly blown by a blower (not shown). On the refrigerant outflow side of the radiator 2, a receiver 2a is provided that separates the gas-liquid of the cooled refrigerant and causes only the liquid refrigerant to flow out to the expansion valve 3 side. The receiver 2 a is formed integrally with the radiator 2.

  The expansion valve 3 is a throttle means for decompressing the high-pressure refrigerant flowing out from the radiator 2 (receiver 2a). The expansion valve 3 of the present embodiment is a temperature-type expansion valve whose valve opening is adjusted according to the temperature of the refrigerant flowing out from the first evaporator 6. The expansion valve 3 of the present embodiment has a function of distributing the decompressed refrigerant to the two flow paths on the nozzle unit 5a side and the second evaporator 7 side of the ejector 5.

  FIG. 2 is a schematic cross-sectional view showing the configuration of the expansion valve 3. The white thick arrow in FIG. 2 represents the flow direction of the refrigerant. FIG. 3 is a schematic cross-sectional view showing a configuration in which the main part of the expansion valve 3 is viewed from the left side of FIG. As shown in FIGS. 2 and 3, the expansion valve 3 has a substantially prismatic main body block 30 made of aluminum alloy or the like. The main body block 30 is formed with an inflow portion 31 into which a refrigerant flows from the radiator 2 side. On the downstream side of the inflow portion 31, an orifice 32 that is partially narrowed in the flow path diameter and extends in the vertical direction in the figure is formed. The orifice 32 squeezes and expands the liquid refrigerant that has flowed into the gas-liquid two-phase. A valve port 33 is formed at the upstream end of the orifice 32. The valve port 33 is configured to be opened and closed by a spherical valve body 34, for example. The valve body 34 is urged in the valve closing direction by a coil spring 35.

  On the downstream side of the orifice 32, there is provided a dryness distribution forming space 36 for forming a dryness distribution in the refrigerant in the mist region immediately after being decompressed by the orifice 32. The dryness distribution forming space 36 has a cylindrical shape with a substantially horizontal central axis C1. The dryness distribution forming space 36 is provided adjacent to the outlet of the orifice 32, and the orifice 32 is in a tangential direction of the dryness distribution forming space 36 (in this example, a tangential direction included in a plane perpendicular to the central axis C1). It is connected. Thereby, in the gas-liquid two-phase refrigerant flowing out from the orifice 32, a swirl flow (represented by solid arrows in FIGS. 2 and 3) along the cylindrical inner wall surface 36a of the dryness distribution forming space 36 is generated.

  When the swirl flow is generated, the liquid-phase refrigerant is easily influenced by the inertial force and therefore gathers on the outer peripheral side of the dryness distribution forming space 36. On the other hand, since the gas-phase refrigerant has a density (specific gravity) smaller than that of the liquid-phase refrigerant and is not easily affected by the inertia force, the gas-phase refrigerant gathers on the central axis C1 side of the dryness distribution forming space 36. Therefore, the dryness distribution forming space 36 forms a dryness distribution with a lower dryness toward the outer peripheral side and a higher dryness toward the central axis C1 with respect to the refrigerant in the mist region immediately after decompression.

  In the main body block 30, a superheat degree detection passage 50 is formed above the dryness distribution forming space 36 as a part of the refrigerant flow path from the first evaporator 6 to the compressor 1. Between the superheat degree detection passage 50 and the dryness distribution forming space 36, there is formed a through hole 51 that is opened in a circular cross section and extends linearly in the vertical direction in FIGS.

  Further, a temperature-sensitive drive unit 52 is attached at a position facing the opening end of the through hole 51 in the superheat degree detection passage 50. The temperature-sensitive drive unit 52 includes a diaphragm 53 formed in a thin film using, for example, stainless steel, and a saturated refrigerant that is sealed by the diaphragm 53 and to which the temperature of the refrigerant flowing through the superheat detection passage 50 is transmitted. Sealed space 54. The diaphragm 53 is deformed and displaced in the vertical direction in FIG. 2 according to the pressure difference between the inside and outside of the sealed space 54.

  An operating rod 55 having a rod-like shape is inserted into the through hole 51 so as to freely advance and retract. One end side of the operating rod 55 is fixed to the diaphragm 53, and the other end side is in contact with the valve body 34 through the dryness distribution forming space 36 and the orifice 32.

  When the superheat degree of the refrigerant passing through the superheat degree detection passage 50 increases and the pressure difference between the inside and outside of the sealed space 54 increases, the diaphragm 53 is displaced downward. As a result, the operating rod 55 is pushed down, so that the valve element 34 moves in the valve opening direction against the urging force of the coil spring 35. On the other hand, when the superheat degree of the refrigerant passing through the superheat degree detection passage 50 decreases and the pressure difference between the inside and the outside of the sealed space 54 decreases, the diaphragm 53 is displaced upward. As a result, the force to push down the operating rod 55 is weakened, and the valve element 34 moves in the valve closing direction by the urging force of the coil spring 35. Therefore, the amount of refrigerant passing through the valve port 33 is adjusted so that the degree of superheat of the refrigerant on the outlet side of the first evaporator 6 becomes a predetermined value.

  A first outlet 41 and a second outlet 42 for distributing and flowing out the gas-liquid two-phase refrigerant are connected to the dryness distribution forming space 36. The first outlet 41 and the second outlet 42 have, for example, the same inner diameter. The first outlet 41 is connected to, for example, the outermost periphery of the dryness distribution forming space 36. The second outlet 42 is connected on the central axis C <b> 1 of the dryness distribution forming space 36. In the present embodiment, the first outlet 41 is located below the second outlet 42. Thereby, the gas-liquid two-phase refrigerant having a relatively low dryness flows out from the first outlet 41, and the gas-liquid having a higher dryness than the refrigerant flowing out from the first outlet 41 from the second outlet 42. Two-phase refrigerant flows out.

  FIG. 4 is a graph showing the distribution ratio of the liquid refrigerant to the first outlet 41 and the second outlet 42 with respect to the dryness of the refrigerant in the expansion valve 3. The horizontal axis of the graph represents the dryness of the gas-liquid two-phase refrigerant in the mist region immediately after being decompressed by the orifice 32. The vertical axis represents the ratio (liquid distribution ratio) q1 / q2 of the mass flow rate q1 of the liquid phase refrigerant distributed to the first outlet 41 to the mass flow rate q2 of the liquid phase refrigerant distributed to the second outlet 42. ing.

  As shown in FIG. 4, the liquid distribution ratio decreases as the dryness of the gas-liquid two-phase refrigerant decreases. For example, when the dryness approaches 0, it becomes difficult for the gas-liquid to be biased by the swirling flow. Therefore, when the first outlet 41 and the second outlet 42 have the same diameter, the liquid distribution ratio is about 1, and the first The liquid refrigerant is distributed almost uniformly to the outlet 41 and the second outlet 42. On the other hand, when the degree of dryness after decompression increases, the liquid-liquid distribution ratio increases because gas-liquid unevenness tends to occur. That is, the liquid-phase rich refrigerant having a relatively low dryness is distributed to the first outlet 41, and the gas-phase rich refrigerant having a relatively high dryness is distributed to the second outlet 42. Considering that the density of the liquid refrigerant is extremely higher than that of the gas phase refrigerant, the mass flow rate of the refrigerant distributed to the first outlet 41 is larger than the mass flow of the refrigerant distributed to the second outlet 42. growing.

  The first outlet 41 is connected to the ejector 5 via a refrigerant pipe. The ejector 5 is a decompression means for decompressing the refrigerant, and is also a fluid circulation means for fluid transportation that circulates the refrigerant by a suction action of the refrigerant flow ejected at a high speed. The ejector 5 takes in the refrigerant flowing out from the first outlet 41 of the expansion valve 3, narrows the passage area thereof, converts the pressure energy of the refrigerant into velocity energy, and isentropically decompressed and expanded with a nozzle portion 5 a And a suction part 5b that is disposed so as to communicate with the refrigerant outlet of the nozzle part 5a and sucks the gas-phase refrigerant from the second evaporator 7 described later.

  The ejector 5 mixes the high-speed refrigerant ejected from the nozzle part 5a and the suction refrigerant from the suction part 5b on the downstream side of the nozzle part 5a and the suction part 5b, and decelerates the mixed refrigerant flow. In addition, a booster 5c that converts pressure energy into pressure energy and boosts the pressure energy is provided. The booster 5c has the above boosting function by being formed in a diffuser shape in which the passage cross-sectional area of the refrigerant gradually increases.

  The 1st evaporator 6 is connected to the refrigerant | coolant flow direction downstream of the pressure | voltage rise part 5c. The 1st evaporator 6 is a heat exchanger (heat absorber) which evaporates the refrigerant | coolant which distribute | circulates the inside by the heat absorption effect | action from the external air forcedly ventilated. The refrigerant outflow side of the first evaporator 6 is connected to the suction side of the compressor 1 by a refrigerant pipe.

  The second outlet 42 of the expansion valve 3 is connected to the suction flow path 9. The suction channel 9 is provided with a capillary 4 which is a throttle means. The capillary 4 performs flow rate adjustment and pressure reduction of the refrigerant flowing into the second evaporator 7 and is formed by a thin tube wound in a spiral shape.

  A second evaporator 7 is provided on the downstream side of the capillary 4. The 2nd evaporator 7 is a heat exchanger (heat absorber) which evaporates the refrigerant | coolant which distribute | circulates the inside by the heat absorption effect | action from the external air forcedly ventilated. The second evaporator 7 is arranged in series on the downstream side of the first evaporator 6 in the flow of external air.

  Here, in the present embodiment, the first evaporator 6 and the second evaporator 7 are integrally formed, and the expansion valve 3 is mechanically directly connected to the first evaporator 6 and the second evaporator 7. Yes. Thereby, since the 1st evaporator 6, the 2nd evaporator 7, and the expansion valve 3 can be handled as an integrated object, mounting to a vehicle becomes easy.

  A control device (not shown) includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. Various control signals from an operation panel (not shown), detection signals from various sensor groups, and the like are input to the control device. The control device controls the operation of various devices (mainly the compressor 1) based on these input signals.

  Next, an example of the operation of the present embodiment based on the above configuration will be described with reference to FIG. When an air conditioning operation signal, a set temperature signal, or the like is input to the control device by an occupant's operation, the control device energizes the electromagnetic clutch of the compressor 1 to bring the electromagnetic clutch into a connected state. Thereby, the rotational driving force is transmitted from the vehicle travel engine to the compressor 1.

  When a control current (control signal) is output from the control device to the electromagnetic capacity control valve of the compressor 1, the discharge capacity of the compressor 1 is adjusted, and the compressor 1 is supplied from the first evaporator 6 to the gas phase refrigerant. Inhale, compress and discharge.

  The high-temperature and high-pressure gas-phase refrigerant compressed and discharged from the compressor 1 flows into the radiator 2. In the radiator 2, the high-temperature and high-pressure refrigerant is cooled and condensed by the outside air of the passenger compartment. The high-pressure refrigerant after heat dissipation flowing out of the radiator 2 flows into the receiver 2a and is separated into two phases of gas and liquid.

  The liquid-phase refrigerant flowing out of the receiver 2a is decompressed by the orifice 32 of the expansion valve 3 and becomes a gas-liquid two-phase mist flow. The gas-liquid two-phase refrigerant in the mist flow flows into the dryness distribution forming space 36, and the dryness distribution is formed by the inertial difference between the gas and liquid. A refrigerant with a relatively low dryness flows out from the first outlet 41, and a refrigerant with the same or higher dryness flows out from the second outlet 42. Thereby, in the expansion valve 3, the refrigerant flow from the first outlet 41 toward the nozzle portion 5a of the ejector 5 and the refrigerant flow from the second outlet 42 through the capillary 4 to the second evaporator 7 have a predetermined mass. Distributed by flow ratio.

  The refrigerant that has flowed into the nozzle portion 5a of the ejector 5 from the first outlet 41 is decompressed and expanded by the nozzle portion 5a. Since the pressure energy of the refrigerant is converted into velocity energy during the decompression and expansion, the refrigerant is ejected at a high speed from the ejection port of the nozzle portion 5a. And the refrigerant | coolant after passing the 2nd evaporator 7 is attracted | sucked from the suction part 5b by the refrigerant | coolant suction action of this refrigerant | coolant jet flow.

  The refrigerant ejected from the nozzle part 5a and the refrigerant sucked by the suction part 5b flow into the pressure increasing part 5c on the downstream side of the nozzle part 5a. In the booster 5c, the refrigerant pressure increases because the velocity energy of the refrigerant is converted into pressure energy by expanding the passage area.

  The refrigerant that has flowed out of the pressure increasing unit 5 c flows into the first evaporator 6. In the first evaporator 6, the low-pressure refrigerant absorbs heat from the external air and evaporates. That is, the external air is cooled. The refrigerant that has passed through the first evaporator 6 is sucked into the compressor 1 and compressed again.

  On the other hand, the refrigerant flowing out from the second outlet 42 of the expansion valve 3 is decompressed by the capillary 4 through the suction flow path 9 and flows into the second evaporator 7 as a low-pressure refrigerant. In the second evaporator 7, the low-pressure refrigerant that has flowed in further absorbs heat from the external air cooled by the first evaporator 6 and evaporates. That is, the external air is further cooled. The refrigerant evaporated in the second evaporator 7 is sucked from the suction part 5b of the ejector 5, mixed with the liquid-phase refrigerant that has passed through the nozzle part 5a by the pressure raising part 5c, and flows into the first evaporator 6.

  Here, the refrigerant flow rate flowing into the nozzle portion 5a of the ejector 5 is referred to as a nozzle flow rate Gn, and the refrigerant flow rate flowing into the suction portion 5b is referred to as a suction flow rate Ge. At this time, the amount of pressure increase by the ejector 5 increases as the flow rate ratio Ge / Gn of the suction flow rate Ge to the nozzle flow rate Gn decreases.

  Therefore, when the heat radiation load of the radiator 2 or the heat absorption load of the first evaporator 6 and the second evaporator 7 (hereinafter, generally referred to as the heat load) is relatively high in summer, the required refrigerating capacity is large. The compressor flow rate G discharged from the compressor 1 is increased. And since the nozzle flow Gn supplied to the nozzle part 5a also increases, nozzle efficiency can be maintained high and ejector efficiency improves. Specifically, as shown in the high load diagram of FIG. 5, the dryness X1 of the refrigerant flowing out from the first outlet 41 and the dryness X2 of the refrigerant flowing out from the second outlet 42 are substantially equal. As a result, the amount of pressure increase by the ejector 5 is ensured, and the effect of improving the refrigeration cycle COP can be maintained high.

  However, when the heat load is low, such as in early spring or winter, the required refrigeration capacity is usually reduced, the compressor flow rate G is reduced, and the nozzle flow rate Gn. As a result, the amount of pressure boosted by the ejector 5 becomes small, and as a result, the COP improvement effect as in the high load state cannot be obtained.

  In the present embodiment, the dryness X1 and X2 of the refrigerant flowing out from the first outlet 41 and the second outlet 42 can be adjusted according to the heat load. In addition, a high COP improvement effect can be obtained.

  That is, as shown in the low load diagram of FIG. 5, when the refrigerant at low load and immediately after depressurization is rich in the gas phase, the dryness X1 of the refrigerant flowing out from the first outlet 41 is determined from the second outlet 42. The dryness of the refrigerant flowing out can be made lower than X2. Thereby, since the flow volume of the liquid-phase refrigerant to the nozzle part 5a side can be increased, the flow rate ratio Ge / Gn can be reduced, and the pressure increase amount by the ejector 5 can be increased. Therefore, the ejector efficiency at the time of low load can be maintained high, and the amount of pressure increase can be secured to improve the refrigeration cycle COP.

  As described above, the expansion valve 3 of the present embodiment uses the first outlet 41 and the second outlet as the refrigerant immediately after being decompressed by the orifice 32 in the dryness distribution forming space 36 adjacent to the downstream side of the orifice 32. 42 is distributed. Since the refrigerant immediately after being depressurized by the orifice 32 becomes a mist flow, it becomes easy to form a dryness distribution of the refrigerant using inertial force. For this reason, by varying the dryness of the refrigerant distributed to the first outlet 41 and the second outlet 42, even when the refrigerant flow is small, a stable flow rate on the nozzle portion 5a side and the second evaporator 7 side. You can make a distribution. Therefore, the capability of the 1st evaporator 6, the 2nd evaporator 7, and the nozzle part 5a can be exhibited efficiently.

  Further, in the present embodiment, since a swirling flow is generated in the refrigerant in the cylindrical dryness distribution forming space 36, the dryness is higher toward the central axis C1 side by utilizing the difference in the inertial force of the gas and liquid. It is possible to easily form a dryness distribution whose dryness is lower toward the side. In the present embodiment, the second outlet 42 is connected on the central axis C <b> 1 of the dryness distribution forming space 36, and the first outlet 41 is connected to the outer peripheral side of the second outlet 42. Accordingly, the liquid-phase rich refrigerant having a low dryness can flow out from the first outlet 41, and the gas-phase rich refrigerant having a high dryness can flow out from the second outlet 42.

  Furthermore, in the present embodiment, in the dryness distribution forming space 36, when the refrigerant flow rate is large and the dryness is low, the refrigerant can be distributed almost evenly to the first outlet 41 and the second outlet 42, and the refrigerant flow rate When there are few and dryness is high, a refrigerant | coolant can be distributed with priority over the 2nd outflow port 42. FIG. Therefore, since the flow distribution of the refrigerant can be controlled according to the heat load, an increase in the degree of superheat in the first evaporator 6 and the second evaporator 7 can be suppressed during a high load, and the liquid phase refrigerant to the compressor 1 can be achieved during a low load. Inflow (liquid back) can be suppressed. Further, even when the refrigerant flow rate is small, the refrigerant can be preferentially flowed to the nozzle portion 5a side, so that the nozzle portion 5a can be choked.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view showing the configuration of the expansion valve 103 in the present embodiment. As shown in FIG. 6, the expansion valve 103 is characterized in that the first outlet 43 is connected to the bottom portion (low height portion) of the dryness distribution forming space 36. In the dryness distribution forming space 36, the dryness is lowered toward the outer peripheral side of the cylinder due to the swirling flow of the refrigerant, and the dryness of the bottom portion is particularly likely to be lowered due to the gravity sedimentation of the liquid-phase refrigerant caused by the gas-liquid density difference.

  In the present embodiment, the first outlet 43 is connected to the bottom of the dryness distribution forming space 36 and the second outlet 42 is connected on the central axis C1 of the dryness distribution forming space 36. A refrigerant with low dryness can flow out from the outlet 41, and a refrigerant with high dryness can flow out from the second outlet 42.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view showing the configuration of the expansion valve 113 in the present embodiment. As shown in FIG. 7, the expansion valve 113 does not need to have a structure in which the dryness distribution forming space 37 generates a swirling flow in the refrigerant, and the trap structure 38 is formed in the dryness distribution forming space 37. It is characterized by a point. The trap structure 38 is provided on the flow path of the refrigerant flowing out from the orifice 32 to the dryness distribution forming space 37. The trap structure 38 has, for example, a plate shape and is arranged horizontally. As a result, the refrigerant flow flowing upward from the orifice 32 collides with the lower surface of the trap structure 38.

  The first outlet 43 is connected to the bottom of the dryness distribution forming space 37, and the second outlet 42 is connected to the upper part of the first outlet 43. For example, the second outlet 42 is connected to the upper part of the trap structure 38.

  Of the gas-liquid two-phase refrigerant that has flowed out of the orifice 32 into the dryness distribution forming space 37, the liquid-phase refrigerant is more susceptible to the inertial force than the gas-phase refrigerant, so that it collides with the trap structure 38 and the flow velocity decreases. The liquid-phase refrigerant having a reduced flow rate gathers in the lower part of the dryness distribution forming space 37 due to gravity sedimentation caused by the gas-liquid density difference. As a result, a dryness distribution is formed in the dryness distribution forming space 37 such that the dryness decreases toward the bottom. Therefore, according to the present embodiment, the refrigerant having a low dryness can be flowed out from the first outlet 43 and the refrigerant having a high dryness can be discharged from the second outlet 42.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic cross-sectional view showing the configuration of the expansion valve 123 in the present embodiment, and shows a cross-section corresponding to FIG. As shown in FIG. 8, the expansion valve 123 is a plate-shaped trap structure that protrudes toward the central axis C <b> 1 side on the cylindrical inner wall surface 36 a of the dryness distribution forming space 36 that becomes the flow path of the swirling flow of the refrigerant. It is characterized in that 39 is formed. The first outlet 41 is connected to the vicinity of the bottom of the dryness distribution forming space 36, and the second outlet 42 is connected to, for example, the central axis C <b> 1 above the first outlet 41.

  The refrigerant flowing out from the orifice 32 into the dryness distribution forming space 36 has a swirl flow along the cylindrical inner wall surface 36a, and the liquid phase refrigerant is more susceptible to the inertial force than the gas phase refrigerant and collides with the trap structure 39. As a result, the flow rate decreases. The liquid-phase refrigerant having a reduced flow rate gathers in the lower part of the dryness distribution forming space 36 due to gravity sedimentation caused by the difference in gas-liquid density. As a result, a dryness distribution is formed in the dryness distribution forming space 36 such that the dryness decreases toward the bottom. Therefore, according to the present embodiment, the refrigerant having a low dryness can be flowed out from the first outlet 41 and the refrigerant having a high dryness can be discharged from the second outlet 42.

(Other embodiments)
In the said 1st Embodiment, although the 1st outflow port 41 is connected below the 2nd outflow port 42, if the connection position of the 1st outflow port 41 is an outer peripheral side rather than the 2nd outflow port 42, it will be. It may be upward or sideward.

  Moreover, in the said embodiment, although the 1st outflow ports 41 and 43 are connected to the nozzle part 5a side, the 2nd outflow port 42 is connected to the 2nd evaporator 7 side, It may be connected to the 2 evaporator 7 side, and the 2nd outflow port 42 may be connected to the nozzle part 5a side.

  Furthermore, although the temperature type expansion valve has been described as an example in the above embodiment, it can also be applied to an electromagnetic type expansion valve.

It is a figure which shows the structure of the vapor compression refrigeration cycle in 1st Embodiment. It is typical sectional drawing which shows the structure of the expansion valve in 1st Embodiment. It is typical sectional drawing which shows the structure which looked at the principal part of the expansion valve in 1st Embodiment from the left side of FIG. It is a graph which shows the distribution ratio of the liquid phase refrigerant | coolant with respect to the dryness of a refrigerant | coolant. It is an operation diagram which shows an example of the action | operation of a refrigerating cycle. It is typical sectional drawing which shows the structure of the expansion valve in 2nd Embodiment. It is typical sectional drawing which shows the structure of the expansion valve in 3rd Embodiment. It is typical sectional drawing which shows the structure of the expansion valve in 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Radiator 3, 103, 113, 123 Expansion valve 5 Ejector 5a Nozzle part 5b Suction part 6 1st evaporator 7 2nd evaporator 31 Inflow part 32 Orifice 34 Valve body 36, 37 Dryness distribution formation space 38 39 Trap structure 41, 43 First outlet 42 Second outlet 52 Temperature-sensitive drive unit

Claims (8)

A compressor (1) for compressing the refrigerant;
A radiator (2) for radiating the refrigerant compressed by the compressor (1);
A part of the refrigerant radiated by the radiator (2) is taken in and ejected from the nozzle part (5a) to form a high-speed refrigerant flow, and the refrigerant flow causes the refrigerant to be drawn from the suction part (5b). An ejector (5) for suction;
A first evaporator (6) that evaporates the refrigerant that has flowed out of the ejector (5) and flows it out toward the compressor (1);
Used in a vapor compression refrigeration cycle including a second evaporator (7) that takes in and evaporates the remaining refrigerant out of the refrigerant radiated by the radiator (2) and flows it out to the suction section (5b) side. An expansion valve,
An inflow part (31) for allowing the refrigerant radiated by the radiator (2) to flow in;
An orifice (32) provided on the downstream side of the inflow part (31), and squeezes and expands the refrigerant flowing into the gas-liquid two-phase refrigerant;
A valve body (34) for adjusting the flow rate of the refrigerant passing through the orifice (32);
A drive unit (52) for driving the valve body (34);
A dryness distribution forming space (36) which is provided adjacent to the downstream side of the orifice (32) and forms a dryness distribution of the refrigerant using inertial force;
A first outlet (41) connected to the dryness distribution forming space (36) and allowing the refrigerant to flow out to one of the nozzle part (5a) side or the second evaporator (7) side;
A refrigerant that is connected to the dryness distribution forming space (36) and has a higher dryness than the refrigerant that flows out of the first outlet (41) is on the nozzle part (5a) side or the second evaporator (7) side. The expansion valve has a second outlet (42) for flowing out to the other of the two.   The dryness distribution forming space (36) has a cylindrical shape in which the orifice (32) is connected in a tangential direction, and generates a swirling flow in the gas-liquid two-phase refrigerant flowing out from the orifice (32). The expansion valve according to claim 1.   The expansion according to claim 2, wherein the first outlet (41) is connected to a cylinder outer peripheral side in the dryness distribution forming space (36) with respect to the second outlet (42). valve.   The expansion valve according to claim 2 or 3, wherein the second outlet (42) is connected on a central axis (C1) of the dryness distribution forming space (36).   The expansion valve according to any one of claims 2 to 4, wherein the first outlet (43) is connected to a bottom of the dryness distribution forming space (36). The dryness distribution forming space (36, 37) has a trap structure (38, 39) formed on the flow path of the refrigerant flowing out from the orifice (32),
The said 1st outflow port (41, 43) is connected below the said 2nd outflow port (42) in the said dryness distribution formation space (36, 37), The Claim 1 or 2 characterized by the above-mentioned. The expansion valve described in 1.   The expansion valve according to any one of claims 1 to 6, wherein the expansion valve is directly connected to at least one of the first evaporator (6) and the second evaporator (7). A compressor (1) for compressing the refrigerant;
A radiator (2) for radiating the refrigerant compressed by the compressor (1);
A part of the refrigerant radiated by the radiator (2) is taken in and ejected from the nozzle part (5a) to form a high-speed refrigerant flow, and the refrigerant flow causes the refrigerant to be drawn from the suction part (5b). An ejector (5) for suction;
A first evaporator (6) that evaporates the refrigerant that has flowed out of the ejector (5) and flows it out toward the compressor (1);
A second evaporator (7) that takes in and evaporates the remaining refrigerant out of the refrigerant radiated by the radiator (2) and causes the refrigerant to flow out toward the suction part (5b);
A vapor compression refrigeration cycle comprising the expansion valve according to any one of claims 1 to 7.

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