JP2006017444A - Ejector cycle and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ejector cycle capable of reducing the increase in cost and mounting space and improving the efficiency of a cycle. <P>SOLUTION: The ejector cycle employs an ejector 13 having a nozzle having one gular section having a minimized refrigerant passage area as a refrigerant decompression means and a refrigerant circulation means in a freezing cycle. A heater 17 is arranged in a part between a radiator 12 and the ejector 13, the enthalpy of the refrigerant is increased by a predetermined amount, and the refrigerant is made to flow into the nozzle in a two-phase state of liquid and vapor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention uses an ejector, which is a decompression means for decompressing a fluid, and a momentum transporting pump that transports fluid by an entrainment action of a working fluid ejected at high speed, as a refrigerant decompression means and a refrigerant circulation means in a refrigeration cycle. The present invention relates to an ejector cycle and a method for controlling the ejector cycle.

  2. Description of the Related Art Conventionally, in a vehicle air conditioner (refrigeration cycle apparatus), a refrigeration cycle (hereinafter referred to as an ejector cycle) including an ejector as means for reducing the pressure of condensed refrigerant is widely known. The ejector is disposed downstream of the refrigerant condenser, and includes a nozzle that ejects the refrigerant guided from the refrigerant condenser at a high speed, a diffuser that diffuses the refrigerant ejected from the nozzle, and the like. Here, when the refrigerant led to the nozzle inlet is a supercooled liquid phase refrigerant, the nozzle efficiency is lowered.

  In order to solve this problem, an ejector cycle including an ejector in which two throats are formed in a nozzle is known from Patent Document 1 (hereinafter referred to as a conventional example). The nozzle 13a disposed in the ejector 13 of the conventional example of FIG. 13 is formed with two throat portions 13j and 13k, an upstream throat portion 13j and a downstream throat portion 13k from the upstream side of the refrigerant flow.

According to this, first, the upstream throat 13j changes the liquid-phase refrigerant flowing into the nozzle into a gas-liquid two-phase flow state. Furthermore, since the cross-sectional area of the refrigerant passage is enlarged between the two throat portions 13j and 13k and the refrigerant is recondensed in a state including fine bubbles, the refrigerant is likely to boil at the downstream throat portion 13k. Accordingly, the droplets of the refrigerant flow from the downstream throat portion 13k to the jet outlet 13h are atomized and approach a homogeneous flow in which the gas-liquid speed difference is further reduced, so that the nozzle efficiency can be improved.
Japanese Patent No. 3331604

  However, the ejector of Patent Document 1 has a problem that the structure of the ejector is complicated because the two throat portions 13j and 13k are formed in the nozzle 13a, in other words, the processing is difficult and the cost is increased. Furthermore, since the two throat portions 13j and 13k are arranged in series in the refrigerant flow direction, there is a problem that the size of the ejector body is increased.

  An object of the present invention is to improve the efficiency of an ejector cycle in an ejector cycle in which an ejector having a simple structure is used as a refrigerant decompression unit and a refrigerant circulation unit.

In order to achieve the above object, according to the first aspect of the present invention, in the ejector cycle, the compressor (11) for bringing the refrigerant into a high-pressure state, and the radiator for radiating the heat of the high-pressure refrigerant discharged from the compressor (11) (12), an evaporator (16) that absorbs heat by evaporating the liquid-phase refrigerant, and one throat portion (13e) that has the smallest refrigerant passage area, and the high-pressure refrigerant that has flowed out of the radiator (12)

A nozzle (13a) that is isentropically decompressed and expanded through the throat (13e), and a vapor-phase refrigerant evaporated in the evaporator (16) by the high-speed refrigerant flow ejected from the nozzle (13a) An ejector (13) having a gas-phase refrigerant inlet (13b) to be sucked and a diffuser (13d) for increasing the pressure of the refrigerant by expanding the cross-sectional area of the refrigerant passage, and the gas flowing out from the ejector (13) The phase refrigerant is sucked into the compressor (11), the liquid refrigerant flowing out of the ejector (13) flows into the evaporator (16), and the high pressure refrigerant flowing out of the radiator (12) is gas-liquid. It is characterized by flowing into the nozzle (13a) in a two-phase state.

  According to this, since the high-pressure refrigerant flowing out from the radiator (12) flows into the nozzle (13a) in a gas-liquid two-phase state, the nozzle (13a) has the same reason as in the conventional example (FIG. 13). The refrigerant tends to boil at the throat (13e). Thereby, since the droplet of the refrigerant | coolant flow which ejects from a nozzle (13a) is atomized and it approaches the homogeneous flow with which the speed difference of the gas-liquid was reduced, nozzle efficiency can be improved.

  In the present invention, the above-described effects can be exhibited by an ejector (13) having a nozzle (13a) having one throat (13e), that is, an ejector (13) having a simpler structure than the conventional example (FIG. 13). Therefore, it is easy to process the ejector (13). Therefore, the cost of the ejector (13) can be reduced. Moreover, since there is one throat portion (13e), the physique in the refrigerant flow direction of the ejector body can be particularly reduced as compared with the conventional example (FIG. 13). That is, since the mounting space for the ejector cycle is reduced as compared with the conventional example, the mounting performance can be improved.

  By the way, when the inlet pressure and outlet pressure of the nozzle (13a) are considered to be constant, when the enthalpy at the inlet of the nozzle (13a) is larger, the adiabatic heat drop (from the enthalpy at the inlet of the refrigerant nozzle (13a) to the nozzle (13a ) Minus the enthalpy at the exit). This is because the slope of the isentropic line increases as the enthalpy increases, and the decompression and expansion of the refrigerant at the nozzle (13a) is performed isentropically.

  Therefore, the adiabatic heat drop is larger in the gas-liquid two-phase state where the enthalpy is larger than the liquid phase as in the present invention, rather than when the refrigerant is in the liquid phase at the nozzle (13a) inlet. The adiabatic heat drop is converted to velocity energy by the nozzle (13a) as input energy of the ejector (13), and this velocity energy is converted to pressure energy by the diffuser (13d). Accordingly, the increase in the adiabatic heat drop increases the amount of pressure increase of the refrigerant pressure in the diffuser (13d), that is, the suction side pressure of the compressor (11) increases, so that the efficiency of the ejector cycle can be enhanced.

  Further, as in the invention according to claim 2, in the ejector cycle according to claim 1, valve means (13f) for increasing or decreasing the opening degree of the nozzle (13a) is arranged in the ejector (13), and the valve means ( If the flow rate of the refrigerant circulating in the cycle is adjusted by increasing / decreasing the opening of the nozzle (13a) to 13f), the high-pressure refrigerant flowing out of the radiator (12) can be made into a gas-liquid two-phase state. If this two-phase refrigerant flows into the nozzle (13a), an ejector cycle having the effect described in claim 1 can be specifically configured.

  Further, as in the invention described in claim 3, in the ejector cycle described in claim 1 or 2, the radiator (12) is provided with a blower (12a) that blows air to exchange heat with the high-pressure refrigerant. If 12a) increases / decreases the air flow rate, the heat load received by the refrigerant in the radiator (12) changes, and specifically, the high-pressure refrigerant flowing out of the radiator (12) can be in a gas-liquid two-phase state. If this two-phase refrigerant flows into the nozzle (13a), an ejector cycle having the effect described in claim 1 can be specifically configured.

  Further, as in the invention according to claim 4, in the ejector cycle according to claim 1, the high-pressure refrigerant discharged from the compressor (11) is supercooled by the radiator (12) to be a supercooled liquid phase refrigerant. If the enthalpy of the supercooled liquid-phase refrigerant is increased by a predetermined amount to bring the high-pressure refrigerant into a gas-liquid two-phase state and this two-phase refrigerant flows into the nozzle (13a), the ejector having the effect described in claim 1 A cycle can be configured.

  Moreover, like the invention of Claim 5, in the ejector cycle of Claim 4, the heating means (17) arrange | positioned in the site | part between a radiator (12) and an ejector (13) is provided, If the enthalpy of the supercooled liquid phase refrigerant is increased by a predetermined amount by heating the supercooled liquid phase refrigerant by the heating means (17), an ejector cycle having the effect described in claim 4 can be configured.

  Further, as in the invention described in claim 6, in the ejector cycle described in claim 5, the heating element for radiating the heat of the heating element (11, 13g) that generates heat by operating the heating means to the supercooled liquid phase refrigerant. It is good also as a thermal radiation part (20).

  Further, as in the invention according to claim 7, in the ejector cycle according to claim 5, the discharge refrigerant heat dissipating part for radiating the heat of the high-temperature refrigerant discharged from the compressor (11) to the supercooling refrigerant as the heating means. (21) may be used.

  According to an eighth aspect of the present invention, in the ejector cycle according to any one of the fourth to seventh aspects, a depressurization for reducing the refrigerant pressure at a portion between the radiator (12) and the ejector (13). Means (22) are provided.

  When the supercooled liquid refrigerant has the same enthalpy, the lower pressure tends to be in a gas-liquid two-phase state. Therefore, the refrigerant flowing into the ejector (13) by the decompression by the decompression means (22) can be reliably gas-liquid two-phased. Moreover, the enthalpy given to the supercooled liquid phase refrigerant can be reduced.

Further, as in the ninth aspect of the invention, in the ejector cycle according to any one of the first to eighth aspects, any one of a freon refrigerant, an HC refrigerant, and a CO ₂ refrigerant is used as the refrigerant. May be.

  Here, chlorofluorocarbon is a general term for organic compounds composed of carbon, fluorine, chlorine, and hydrogen, and is widely used as a refrigerant. Fluorocarbon refrigerants include HCFC (hydro-chloro-fluoro-carbon) refrigerants, HFC (hydro-fluoro-carbon) refrigerants, etc. These are refrigerants called substitute chlorofluorocarbons because they do not destroy the ozone layer. is there.

  The HC (hydrocarbon) refrigerant is a refrigerant substance that contains hydrogen and carbon and exists in nature. Examples of the HC refrigerant include R600a (isobutane) and R290 (propane).

  When the carbon dioxide refrigerant is used as the refrigerant, the effects described in the claims 1 to 8 can be exhibited when the carbon dioxide does not exceed the critical point on the high pressure side.

  As in the invention according to claim 10, in the method for controlling the ejector cycle according to claim 1, when the dryness of the high-pressure refrigerant flowing into the nozzle (13a) is defined as the nozzle inlet dryness, the nozzle inlet dryness The degree is controlled to a target value.

  According to this, the effect of the invention of claim 1, that is, the effect of improving the nozzle efficiency and the effect of improving the efficiency of the ejector cycle can be surely exhibited.

  As in the invention described in claim 11, based on the refrigerant passage area of the throat (13e), the flow rate of the high-pressure refrigerant passing through the throat (13e), and the pressure difference between the refrigerant inlets and outlets in the nozzle (13a). 11. The invention according to claim 10, wherein the nozzle inlet dryness is calculated, and one or more factors among the factors affecting the nozzle inlet dryness are adjusted based on the calculation result of the nozzle inlet dryness. can do.

  In addition, about each physical quantity of the pressure difference between the refrigerant | coolant passage area of a throat part (13e), the flow volume of the high pressure refrigerant | coolant which passes a throat part (13e), and the refrigerant | coolant inlet / outlet in the said nozzle (13a), these are detected directly. Or may be obtained from alternative physical quantities whose physical quantities can be estimated.

  When the refrigerant is a non-azeotropic refrigerant or a pseudo-azeotropic refrigerant as in the invention described in claim 12, the refrigerant pressure on the refrigerant inlet side of the nozzle (13a) and the refrigerant on the refrigerant inlet side of the nozzle (13a) The nozzle inlet dryness is calculated based on the temperature, and one or more factors among the factors affecting the nozzle inlet dryness are adjusted based on the calculation result of the nozzle inlet dryness. The invention can be carried out.

  In addition, about each physical quantity of the refrigerant | coolant pressure by the side of the refrigerant | coolant inlet of a nozzle (13a), and the refrigerant | coolant temperature of the refrigerant | coolant inlet side of a nozzle (13a), they may be detected directly, or those The physical quantity may be obtained from an alternative physical quantity that can be estimated.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
In the present embodiment, the ejector cycle according to the present invention is applied to a refrigeration cycle of a vehicle air conditioner, and FIG. 1 is a schematic diagram of the refrigeration cycle according to the present embodiment. In FIG. 1, 11 is a compressor 11 that sucks and compresses refrigerant. The refrigerant that has become a high pressure state by the compressor 11 flows into the radiator 12. In the radiator 12, the high-pressure refrigerant radiates heat to the outdoor air, in other words, the refrigerant is cooled by the outdoor air and condensed into a liquid phase.

  The high-pressure refrigerant that has entered the liquid phase flows into the ejector 13. The ejector 13 decompresses and expands the refrigerant flowing out of the radiator 12 and sucks the gas-phase refrigerant evaporated in the evaporator 16 described later, and converts the expansion energy into pressure energy to increase the suction pressure of the compressor 11. ing. Details of the ejector 13 will be described later.

  The refrigerant that has flowed out of the ejector 13 flows into the gas-liquid separator 14. In the gas-liquid separator 14, the refrigerant that has flowed is separated into a gas-phase refrigerant and a liquid-phase refrigerant and stored, and the separated gas-phase refrigerant is sucked into the compressor 11 and compressed again. The liquid refrigerant thus drawn is sucked to the evaporator 16 side.

  The evaporator 16 exhibits cooling capability by heat-exchanging the liquid-phase refrigerant with the air blown into the room and evaporating. The first decompressor 15 disposed between the gas-liquid separator 14 and the evaporator 16 is a throttle (decompression) means for decompressing the liquid-phase refrigerant sucked from the gas-liquid separator 14 to the evaporator 16 side. The pressure in the evaporator 16 (evaporation pressure) is reliably reduced by the first decompressor 15. In the present embodiment, a heater 17 that heats the refrigerant is disposed at a portion between the radiator 12 and the ejector 13.

  As shown in FIG. 2, the ejector 13 uses a nozzle 13 a that converts the pressure energy of the high-pressure refrigerant flowing into velocity energy to decompress and expand the refrigerant, and a high-speed refrigerant flow ejected from the nozzle 13 a in the evaporator 16. A gas-phase refrigerant inlet 13b through which the evaporated gas-phase refrigerant is sucked, a mixing unit 13c that mixes the sucked gas-phase refrigerant and the refrigerant flow ejected from the nozzle 13a, a refrigerant jetted from the nozzle 13a, and the evaporator 16 It comprises a diffuser 13d and the like for increasing the pressure of the refrigerant by converting the velocity energy into pressure energy while mixing with the refrigerant sucked from.

  In the present embodiment, a divergent nozzle having one throat portion 13e having the smallest refrigerant passage area in the middle of the refrigerant passage is used as the nozzle 13a. Further, a needle valve 13f is arranged as a valve means for increasing or decreasing the opening degree of the throat portion 13e by displacing in the left-right direction in FIG. The displacement of the needle valve 13f is performed by a displacement means. In the present embodiment, a solenoid that displaces the needle valve 13f by a magnetic force generated by energizing the solenoid coil 13g (see FIG. 1) is used as the displacement means.

  In the mixing unit 13c, the mixing is performed so that the sum of the momentum of the refrigerant flow injected from the nozzle 13a and the momentum of the refrigerant flow sucked from the evaporator 16 to the ejector 13 is preserved. However, the static pressure of the refrigerant increases. On the other hand, in the diffuser 13d, the refrigerant passage cross-sectional area gradually increases, so that the dynamic pressure of the refrigerant is converted into a static pressure.

  The operations of the compressor 11, the heater 17, and the solenoid 13g according to the present embodiment are controlled by a control signal from a control device (not shown).

  Next, the operation of the present embodiment in the above configuration will be described based on the ph diagram of FIG. Here, points A1 to A9 in FIG. 1 correspond to points A1 to A9 in FIG. When the compressor 11 is started, the gas-phase refrigerant is sucked into the compressor 11 from the gas-liquid separator 14, and the compressed refrigerant is discharged to the radiator 12 (A7G → A1). The refrigerant flowing into the radiator 12 radiates heat to the air, that is, is cooled by the air. In the present embodiment, the refrigerant is supercooled beyond the saturated liquid line (A1 → A2).

  The refrigerant flowing out of the radiator 12 is heated by the heater 17. That is, the enthalpy is increased by the heater 17 and a gas-liquid two-phase state is obtained (A2 → A3). The refrigerant in the two-phase state flows into the nozzle 13a of the ejector 13, passes through the throat portion 13e, is ejected from the ejection port 13h, and isentropically decompressed and expanded (A3 → A4). At this time, the gas-phase refrigerant evaporated by the evaporator 16 is sucked from the gas-phase refrigerant inlet 13b by the entrainment effect of the refrigerant flow ejected at a high speed.

  Next, the refrigerant sucked from the evaporator 16 and the refrigerant jetted from the nozzle 13a are mixed in the mixing unit 13c (A4 → A5, A9 → A5), and the dynamic pressure is converted into static pressure by the diffuser 13d. It flows into the liquid separator 14. The gas-phase refrigerant in the gas-liquid separator 14 is sucked into the compressor 11 and circulates through the cycle again (A7G → A1). The reason why the point A7G is not located on the saturated vapor line is that heat is absorbed by the pipe from the gas-liquid separator 14 to the compressor 11.

  On the other hand, since the refrigerant in the evaporator 16 is sucked by the ejector 13, the liquid-phase refrigerant flows into the evaporator 16 from the gas-liquid separator 14, and the refrigerant that flows in absorbs heat from the air blown into the room and evaporates. (A7L → A9).

  Further, the displacement of the needle valve 13f by the solenoid 13g, that is, the opening degree of the nozzle 13a is controlled by a control signal from a control device (not shown). According to this, for example, when the compressor 11 rotates at a high speed, that is, when there is a large amount of refrigerant flowing into the ejector 13, the opening degree of the nozzle 13a can be increased to increase the amount of refrigerant passing through the nozzle 13a (ejector 13). Therefore, since the amount of refrigerant flowing through the evaporator 16 on the downstream side of the refrigerant flow of the ejector 13 increases, the refrigeration (cooling) capacity can be improved.

  Next, the operational effects of the first embodiment will be described. (1) Since the refrigerant in the gas-liquid two-phase state is caused to flow into the nozzle 13a, the nozzle efficiency is improved and the cycle efficiency of the ejector cycle can be improved.

  More specifically, in this embodiment, the high-pressure refrigerant that has flowed out of the radiator 12 is heated by the heater 17, that is, the enthalpy is increased and flows into the nozzle 13a in a gas-liquid two-phase state. Therefore, the refrigerant is likely to boil at the throat 13e of the nozzle 13a. Thereby, the droplet of the refrigerant | coolant flow after passing through the throat part 13e is atomized, and it approaches the homogeneous flow in which the gas-liquid speed difference is reduced. That is, the nozzle efficiency for converting the refrigerant energy (input energy) at the inlet of the nozzle 13a into velocity energy is increased. Thereby, the cycle efficiency of the ejector cycle can be improved.

  (2) Since the ejector 13 equipped with the nozzle 13a having one throat portion 13e is used for the above-described operational effect (1), the cost of the ejector 13 can be reduced, and the size of the ejector 13 can be further reduced.

  In the present embodiment, the effect (1) can be exhibited by the ejector 13 including the nozzle 13a having one throat portion 13e, that is, the ejector 13 having a simple structure as compared with the conventional example (FIG. 13). Naturally, since the processing of the ejector 13 becomes easy, the cost of the ejector 13 can be reduced. Moreover, since there is one throat portion 13e, the physique of the ejector body in the refrigerant flow direction is particularly reduced as compared with the case where the throat portions 13j and 13k are arranged in series as in the conventional example (FIG. 13). be able to. That is, since the mounting space for the ejector cycle is reduced as compared with the conventional example, the mounting performance can be improved.

  (3) Since the refrigerant in the gas-liquid two-phase state having a larger adiabatic heat drop is caused to flow into the ejector 13 (nozzle 13a), the refrigerant pressure flowing out from the ejector 13, that is, the suction pressure of the compressor 11 can be increased.

  Here, the cycle efficiency is considered using an ejector cycle having a supercooling degree as shown in FIG. 14 (hereinafter referred to as a comparative example) and a ph diagram (FIG. 3) of the present embodiment. Assuming that the inlet pressure and outlet pressure of the nozzle 13a are constant, the adiabatic heat drop is greater when the enthalpy at the inlet of the nozzle 13a is larger (the enthalpy at the inlet of the nozzle 13a minus the enthalpy at the outlet of the nozzle 13a). Becomes larger. This is because the slope of the isentropic line increases as the enthalpy increases, and the decompression and expansion of the refrigerant in the nozzle 13a is performed isentropically.

  Therefore, the adiabatic heat drop is larger in the gas-liquid two-phase state where the enthalpy is larger than the liquid phase as in the present invention, rather than when the refrigerant is in the liquid phase at the nozzle 13a inlet. The adiabatic heat drop Δh ′ of the present embodiment is larger than the adiabatic heat drop Δh ′ of the conventional example.

  The adiabatic heat drop Δh, Δh ′ is converted into velocity energy by the nozzle 13a as input energy of the ejector 13, and this velocity energy is converted into pressure energy by the diffuser 13d. Accordingly, the larger the heat insulation heat difference, the greater the amount of pressure increase of the refrigerant pressure in the diffuser 13d, that is, the suction side pressure of the compressor 11 is increased. Therefore, the efficiency of the ejector cycle can be increased.

  Therefore, since the pressure increase ΔP in the ejector 13 of the present embodiment having a large adiabatic heat drop is larger than the pressure increase ΔP ′ in the ejector 13 of the conventional example, the efficiency of the ejector cycle is increased. FIG. 4 shows changes in cycle efficiency when the state other than the refrigerant state at the inlet of the nozzle 13a is the same (for example, the refrigerant circulation amount). As described above, it has been confirmed that the cycle efficiency is higher in the case of flowing into the nozzle 13a in the gas-liquid two-phase state.

(Second Embodiment)
This embodiment of FIG. 5 has substantially the same configuration as that of the first embodiment, but instead of the heater 17 in the first embodiment, it flows out of the radiator 12 by the heat of the displacement means (solenoid coil 13g) that is a heating element. A heating element heat dissipating section 20 for heating the refrigerant is provided.

  According to this, since it is not necessary to provide the heater 17, an ejector cycle having the operational effects (1) to (3) described in the first embodiment can be configured with a simpler configuration.

(Third embodiment)
The present embodiment in FIG. 6 has substantially the same configuration as the first embodiment, but the refrigerant that has flowed out of the radiator 12 by the heat of the high-temperature and high-pressure refrigerant discharged from the compressor 11 instead of the heater 17 in the first embodiment. The discharge refrigerant heat dissipating part 21 is provided.

  Also by this, since the heater 17 does not need to be provided, the ejector cycle having the effects (1) to (3) described in the first embodiment can be configured with a simpler configuration.

(Fourth embodiment)
This embodiment of FIG. 7 has substantially the same configuration as that of the first embodiment, but a second pressure reducer 22 that is a pressure reducing means for reducing the pressure of the refrigerant is disposed at the refrigerant flow downstream side portion of the heater 17. If it demonstrates using the ph diagram of FIG. 8, the refrigerant | coolant heated with the heater 17 will be in a gas-liquid two-phase state by the pressure_reduction | reduced_pressure in the 2nd pressure reduction device 22 (A3-> A31).

  Thereby, the refrigerant flowing into the ejector 13 can be reliably gas-liquid two-phased. Furthermore, the amount of heat given to the refrigerant by the heater 17 can be reduced.

  In this embodiment, the effects (1) to (3) described in the first embodiment can be exhibited.

(Fifth embodiment)
The present embodiment in FIG. 9 has substantially the same configuration as the first embodiment, but the heater 17 in the first embodiment is eliminated. And the compressor 11 of this embodiment, the solenoid coil 13g which displaces the needle valve 13f which increases / decreases the opening degree of the ejector 13, and the air blower 12a which blows air to the heat radiator 12 are electronic control apparatuses (ECU not shown). It is controlled by the control signal from Furthermore, the refrigerant pressure, temperature, etc. downstream of the radiator 12 are input to this electronic control device from a sensor or the like.

  The electronic control unit operates the compressor 11 and the blower 12a so that the refrigerant pressure, temperature, etc., on the downstream side of the radiator 12 are the pressure and temperature in the region where the refrigerant is in the gas-liquid two phase. The amount of air blown (heat load on the radiator 12) and the opening of the ejector 13 (flow rate of refrigerant passing through the ejector 13) are controlled.

  Thereby, compared with 1st Embodiment, the ejector cycle which has the effect (1)-(3) described in 1st Embodiment with a simpler structure can be comprised.

(Sixth embodiment)
In the sixth embodiment shown in FIG. 11, the heater 17 in the first embodiment is eliminated, and an internal heat exchanger 23 is provided between the suction side of the compressor 11 and the outlet side of the radiator 12. The internal heat exchanger 23 cools the high-pressure liquid refrigerant on the outlet side of the radiator 12 with a low-temperature low-pressure refrigerant, thereby increasing the degree of supercooling of the high-pressure liquid refrigerant on the outlet side of the radiator 12.

  Then, the operation of the compressor 11 and the opening of the ejector 13 (the refrigerant flow rate passing through the ejector 13) are controlled to make the refrigerant flowing into the ejector 13 into a gas-liquid two-phase.

(Seventh embodiment)
The seventh embodiment shown in FIG. 12 shows an example in which the present invention is applied to an ejector cycle in which the gas-liquid separator 14 is eliminated.

  In the present embodiment, as shown in FIG. 12, the refrigerant passage on the outlet side of the radiator 12 is branched into two, and one refrigerant passage is formed in the ejector 13 via the first decompressor 15 and the evaporator 16. The other refrigerant passage is directly connected to the nozzle 13a in the ejector 13 and is connected to the gas-phase refrigerant inlet 13b.

  Further, a second evaporator 24 is provided on the outlet side of the ejector 13 instead of the gas-liquid separator 14. The second evaporator 24 exhibits cooling capability by exchanging heat between the refrigerant and the air blown into the room to evaporate the refrigerant (heat absorption). Then, the refrigerant flowing out from the second evaporator 24 is sucked into the compressor 11 and compressed.

  Incidentally, according to the present embodiment, the cooling capacity of the two evaporators 16 and 24 can be made different to cool any two locations in the passenger compartment or two separate passenger compartments at optimum temperatures. it can.

(Eighth embodiment)
The present embodiment shows a method for controlling the dryness of the high-pressure refrigerant when flowing into the nozzle 13a (hereinafter referred to as nozzle inlet dryness).

  First, the refrigerant passage area of the throat portion 13e in the nozzle 13a, the flow rate of the high-pressure refrigerant passing through the throat portion 13e, and the pressure difference between the refrigerant inlet and outlet in the nozzle 13a are detected, and the dryness of the nozzle inlet is determined based on their physical quantities. Calculate from the conservation law.

  Next, the calculation result of the nozzle inlet dryness is compared with the target value of the nozzle inlet dryness, and a control factor that influences the nozzle inlet dryness (that is, the refrigerant passage area of the throat 13e and the throat 13e are passed through). The nozzle inlet dryness is controlled to a target value by adjusting one or more factors of the flow rate of the high-pressure refrigerant and the pressure difference between the refrigerant inlet and outlet of the nozzle 13a.

  Thus, by controlling the nozzle inlet dryness to the target value, the effect of improving the nozzle efficiency and the effect of improving the efficiency of the ejector cycle can be surely exhibited.

  It should be noted that the physical quantities of the refrigerant passage area of the throat portion 13e, the flow rate of the high-pressure refrigerant passing through the throat portion 13e, and the pressure difference between the refrigerant inlets and outlets of the nozzle 13a when calculating the nozzle inlet dryness are directly calculated. Or may be obtained from an alternative physical quantity that can be estimated as described in detail below.

  For example, in the case of a variable nozzle that increases or decreases the opening degree of the throat 13e with the needle valve 13f as shown in FIG. 2, the refrigerant passage area of the throat 13e may be estimated from the position information of the needle valve 13f.

  The flow rate of the high-pressure refrigerant passing through the throat 13e is calculated from the number of revolutions of the compressor 11, the discharge capacity per revolution of the compressor 11, the density of refrigerant sucked into the compressor 11, and the volume efficiency of the compressor 11. May be. In addition, the density of the refrigerant sucked into the compressor 11 may be substituted with the suction pressure of the compressor 11 or a low pressure system pressure corresponding to the suction pressure, and a temperature (low pressure two-phase region temperature) at which the low pressure system pressure can be estimated.

  The pressure difference between the refrigerant inlet and outlet in the nozzle 13a is any one or more of the refrigerant inlet pressure in the nozzle 13a or a high pressure system pressure equivalent thereto, and a temperature that can estimate the high pressure system pressure (high pressure two-phase region temperature). It may be detected as a difference between any one or more of a factor, a refrigerant outlet pressure in the nozzle 13a or a low-pressure system pressure equivalent thereto, and a temperature (low-pressure two-phase region temperature) that can estimate the low-pressure system pressure. .

  Further, as an adjustment method for controlling the nozzle inlet dryness to the target value, as described in detail below, the control factor may be adjusted directly or a method of adjusting it indirectly.

  For example, in the case of a variable nozzle that increases or decreases the opening of the throat 13e with the needle valve 13f as shown in FIG. 2, the refrigerant passage area of the throat 13e is controlled by adjusting the position of the needle valve 13f.

  The flow rate of the high-pressure refrigerant passing through the throat 13e is determined by the number of revolutions of the compressor 11, the discharge capacity in the case of the variable capacity compressor 11, and the opening of the flow rate adjusting valve provided in the cycle (for example, upstream of the nozzle 13a) You may adjust.

  The pressure difference between the refrigerant inlet and outlet in the nozzle 13a adjusts a factor that fluctuates the pressure balance of the refrigeration cycle. Specifically, for example, the cooling air volume of the radiator 12, the refrigerant flow rate of the radiator 12, the cooling air volume of the evaporator 16, the refrigerant flow rate of the evaporator 16, the refrigerant flow rate of the internal heat exchanger 23, and the like are adjusted.

  Incidentally, by providing a bypass circuit for the radiator 12, the evaporator 16, and the internal heat exchanger 23 and opening and closing the bypass circuit, the refrigerant flow rate of the radiator 12, the refrigerant flow rate of the evaporator 16, and the internal heat exchange are provided. The refrigerant flow rate of the vessel 23 can be adjusted.

  Note that the factors necessary for calculating the above-described dryness of the nozzle inlet and the adjustment factors for the target value are merely examples, and any detection factors and adjustment factors may be used as long as each control factor is varied.

  Further, the target value of the nozzle inlet dryness differs depending on each refrigerant and system, but physically it can be controlled from the dryness 0 (saturated liquid state) to the dryness 1 (saturated gas state).

  Further, as a specific control method, a method of calculating a nozzle inlet dryness by inputting a signal of a detected physical quantity may be used, or a method of mapping an output value for a detection signal in the system in advance may be used. . Moreover, even if it is another method, if a detection factor and an adjustment factor are contained, it is equivalent to what the present invention intends.

Other Embodiments In the above-described embodiment, an example in which a divergent nozzle is used as the nozzle 13a has been shown. However, as long as the nozzle 13a has one throat portion 13e, various applications such as a tapered nozzle and a Laval nozzle are applicable.

  In the second embodiment described above, in the heating element heat radiating section 20, the solenoid coil 13g that is a heating element radiates heat to the supercooled refrigerant that has flowed out of the radiator 12, but the heating element is in the ejector cycle. It may be a compressor or a heating element outside the cycle, such as an engine.

  Further, in the above-described fourth embodiment, the example in which the refrigerant after the second decompressor 22 is heated by the heater 17 is depressurized has been described. However, the second decompressor 22 is disposed upstream of the heater 17 before heating. The refrigerant may be decompressed, or the refrigerant being heated may be decompressed.

  In the fifth embodiment described above, the electronic control device controls the operation of the compressor 11, the blower amount of the blower 12 a, and the opening degree of the ejector 13 at the same time. However, these controls are performed independently. Therefore, only one of the controls may be performed. Further, for example, two arbitrary controls may be performed, such as an air flow rate and an ejector opening degree.

  Moreover, although the example which applied this invention to the vehicle air conditioner was shown in the above-mentioned embodiment, even if this invention is applied not only to a vehicle air conditioner but to vapor compression-type cycles, such as a heat pump cycle for water heaters. Good. Also, the installation location is not limited to a moving body such as a vehicle, and it may be fixed.

The refrigerant is not limited to the type of refrigerant in the above embodiments, the fluorocarbon refrigerant, HC-based refrigerant, CO, etc. ₂ refrigerant is applicable. When carbon dioxide refrigerant is used as the refrigerant, the above-described effects can be exhibited when carbon dioxide does not exceed the critical point on the high pressure side.

  Further, when a non-azeotropic refrigerant (R404A or the like) or a pseudo-azeotropic refrigerant (R410A or the like) is used as the refrigerant, a one-to-one relationship is established between the pressure and the temperature even in the two-phase region. The nozzle inlet dryness may be calculated based on the refrigerant pressure on the refrigerant inlet side of 13a and the refrigerant temperature on the refrigerant inlet side of the nozzle 13a. The nozzle inlet dryness may be controlled to a target value by adjusting one or more factors among the factors affecting the nozzle inlet dryness based on the calculation result of the nozzle inlet dryness. .

  The physical quantities of the refrigerant pressure on the refrigerant inlet side of the nozzle 13a and the refrigerant temperature on the refrigerant inlet side of the nozzle 13a may be detected directly, or the physical quantities can be estimated. It may be obtained from an alternative physical quantity.

  In the first to sixth embodiments described above, an example in which the liquid-phase refrigerant separated by the gas-liquid separator 14 is evaporated by one evaporator 16 and is supplied to the gas-phase refrigerant inlet 13 b in the ejector 13. In the ejector cycle in which the liquid-phase refrigerant separated by the gas-liquid separator 14 is evaporated by the plurality of evaporators 16 and supplied to the gas-phase refrigerant inlet 13b in the ejector 13. The invention can be applied.

1 is a schematic diagram showing a first embodiment in which the present invention is applied to a refrigeration cycle of a vehicle air conditioner. It is sectional drawing of the ejector which concerns on 1st Embodiment of this invention. It is a ph diagram of a 1st embodiment and a comparative example. It is a figure which shows the relationship between the refrigerant | coolant state of an ejector inlet, and cycle performance. It is a schematic diagram of the ejector cycle which concerns on 2nd Embodiment of this invention. It is a schematic diagram of the ejector cycle which concerns on 3rd Embodiment of invention. It is a schematic diagram of the ejector cycle which concerns on 4th Embodiment of this invention. It is a ph diagram of the fourth embodiment. It is a schematic diagram of the ejector cycle which concerns on 5th Embodiment of this invention. It is a ph diagram of the fifth embodiment. It is a schematic diagram of the ejector cycle which concerns on 6th Embodiment of this invention. It is a schematic diagram of the ejector cycle which concerns on 7th Embodiment of this invention. It is sectional drawing of the ejector which concerns on patent document 1. FIG. It is a schematic diagram which shows the ejector cycle of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Compressor heating element, 12 ... Radiator, 12a ... Blower, 13 ... Ejector, 13a ... Nozzle, 13b ... Gas-phase refrigerant inlet, 13d ... Diffuser, 13e ... Throat, 13f ... Needle valve valve means, 13g ... Solenoid coil heating element, 14 ... gas-liquid separator, 16 ... evaporator, 17 ... heater heating means, 20 ... heating element heat radiation part, 21 ... discharged refrigerant heat radiation part, 22 ... second decompressor pressure reduction means.

Claims (13)

A compressor (11) for bringing the refrigerant into a high pressure state;
A radiator (12) for radiating heat of the high-pressure refrigerant discharged from the compressor (11);
An evaporator (16) that absorbs heat by evaporating the liquid-phase refrigerant;
A nozzle having one throat portion (13e) in which the refrigerant passage area is reduced most, and the high-pressure refrigerant flowing out of the radiator (12) passes through the throat portion (13e) and isentropically decompressed and expanded ( 13a), a gas-phase refrigerant inlet (13b) into which the vapor-phase refrigerant evaporated in the evaporator (16) by the high-speed refrigerant flow ejected from the nozzle (13a) is sucked into the refrigerant passage, An ejector (13) having a diffuser (13d) for expanding the area and increasing the pressure of the refrigerant,
The gas-phase refrigerant that has flowed out of the ejector (13) is sucked into the compressor (11), and the liquid-phase refrigerant that has flowed out of the ejector (13) flows into the evaporator (16),
The ejector cycle characterized in that the high-pressure refrigerant that has flowed out of the radiator (12) flows into the nozzle (13a) in a gas-liquid two-phase state. The ejector (13) includes valve means (13f) for increasing or decreasing the opening of the nozzle (13a),
The valve means (13f) increases or decreases the opening of the nozzle (13a) so that the high-pressure refrigerant flowing out of the radiator (12) flows into the nozzle (13a) in a gas-liquid two-phase state. The ejector cycle according to claim 1, wherein: A fan (12a) for blowing air to exchange heat with the high-pressure refrigerant to the radiator (12),
The high-pressure refrigerant that has flowed out of the radiator (12) flows into the nozzle (13a) in a gas-liquid two-phase state when the blower (12a) increases or decreases the amount of blown air. The ejector cycle according to claim 1 or 2. The high-pressure refrigerant discharged from the compressor (11) is supercooled by the radiator (12) to become a supercooled liquid phase refrigerant, and the supercooled liquid phase refrigerant is gasified by increasing the enthalpy by a predetermined amount. The ejector cycle according to claim 1, wherein the ejector cycle is in a liquid two-phase state and flows into the nozzle (13a). Heating means (17) disposed at a portion between the radiator (12) and the ejector (13);
The ejector cycle according to claim 4, wherein the heating means (17) increases the enthalpy of the supercooled liquid phase refrigerant by a predetermined amount by heating the supercooled liquid phase refrigerant. 6. The ejector cycle according to claim 5, wherein the heating means is a heating element heat radiating section (20) for radiating heat of the heating element (11, 13g) that generates heat upon operation to the supercooled liquid phase refrigerant. . The ejector cycle according to claim 5, wherein the heating means is a discharge refrigerant heat radiating section (21) for radiating heat of the high-temperature refrigerant discharged from the compressor (11) to the supercooled refrigerant. The ejector cycle according to any one of claims 4 to 7, further comprising a decompression means (22) for decompressing a refrigerant pressure at a portion between the radiator (12) and the ejector (13). . The refrigerant, chlorofluorocarbon refrigerants, HC-based refrigerant, an ejector cycle according to any one of claims 1 to 8, characterized in that any one of the CO ₂ refrigerant. 2. The ejector cycle according to claim 1, wherein when the dryness of the high-pressure refrigerant when flowing into the nozzle (13 a) is defined as a nozzle inlet dryness, the nozzle inlet dryness is controlled to a target value. 3. Control method. The nozzle inlet dryness is calculated based on the refrigerant passage area of the throat (13e), the flow rate of the high-pressure refrigerant passing through the throat (13e), and the pressure difference between the refrigerant inlets and outlets of the nozzle (13a). ,
The method for controlling an ejector cycle according to claim 10, wherein one or more factors affecting the nozzle inlet dryness are adjusted based on the calculation result of the nozzle inlet dryness. The refrigerant is a non-azeotropic refrigerant or a pseudo-azeotropic refrigerant,
Based on the refrigerant pressure on the refrigerant inlet side of the nozzle (13a) and the refrigerant temperature on the refrigerant inlet side of the nozzle (13a), the nozzle inlet dryness is calculated,
The method for controlling an ejector cycle according to claim 10, wherein one or more factors affecting the nozzle inlet dryness are adjusted based on the calculation result of the nozzle inlet dryness. The refrigerant, chlorofluorocarbon refrigerants, HC-based refrigerant, the control method of the ejector cycle according to any one of claims 10 to 12, characterized in that any one of the CO ₂ refrigerant.

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