JP4232567B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus used in a vehicle air conditioner and an electric water heater, and particularly relates to a refrigeration cycle apparatus including an ejector capable of changing a nozzle diameter according to a load variation.

  Conventionally, as shown in FIG. 14, the compressor 101, the gas cooler 102, the ejector 103, and the gas-liquid separator 104 are connected in a ring shape by refrigerant piping, and the liquid-phase refrigerant separated by the gas-liquid separator 104 is fixed to the fixed throttle 105. An ejector cycle has been proposed in which suction is performed by the low pressure inlet 108 of the ejector 103 via a decompression device such as the above and a bypass pipe provided with the evaporator 106 (see, for example, Patent Document 1). The ejector 103 is provided with a fixed nozzle 107 whose nozzle outlet diameter (opening area) is always a constant nozzle outlet diameter regardless of the circulating flow rate of the cooling.

  Here, when the above ejector cycle is used as a refrigeration cycle of a vehicle air conditioner, for example, the load fluctuation range of the use environment is very large from a high load such as rapid cooling in summer to a low load such as dehumidification in winter. The fixed nozzle 107 cannot sufficiently cope with the load fluctuation. Therefore, as shown in FIG. 15, as a variable throttle mechanism that optimally controls the throttle diameter according to the load fluctuation, that is, the nozzle outlet diameter according to the refrigerant circulation flow rate, the needle outlet diameter (throttle throttle) is controlled by a needle valve. An ejector cycle provided with an ejector 103 provided with a variable nozzle 109 capable of varying the diameter) has also been proposed. (For example, refer to Patent Document 2).

And the normal control in the refrigerating cycle using a variable ejector is controlling to the optimal high-pressure control pressure so that it may become the relationship shown in the graph of FIG. FIG. 4 is a graph showing an optimum discharge pressure control line (control line with the maximum coefficient of performance COP of the ejector cycle) with respect to the gas cooler outlet refrigerant temperature Tgc.
Japanese Patent Laid-Open No. 11-37577 (page 2-4, FIG. 1) Japanese Patent Laid-Open No. 5-31421 (page 2-3, FIG. 1 to FIG. 2)

  In a refrigeration cycle applied to a vehicle air conditioner, under conditions where the outside air temperature is low and the vehicle speed is high, the high-pressure side refrigerant pressure is low, and the load on the refrigerant evaporator is high (the intake air temperature is high or the air volume is large). When such a condition is applied, the low-pressure side refrigerant pressure increases, and as a result, the refrigerant pressure difference between the high and low pressures becomes small in the refrigeration cycle (hereinafter, this state is referred to as a low-temperature inside air mode). FIG. 16 is a graph showing the relationship between the throttle diameter and the blowing temperature in the expansion valve cycle, and FIG. 17 is a graph showing the relation between the throttle diameter (nozzle diameter) and the blowing temperature in the ejector cycle.

  In the case of an expansion valve cycle, even if it becomes such a state, it is easy to set an appropriate expansion valve throttle diameter and increase the compressor speed for an electric compressor or increase the compressor capacity for a variable capacity compressor. It is possible to create a desired evaporator blowing temperature (for example, about 3 ° C. during dehumidifying heating). However, in the case of the ejector cycle, cooling is performed by collecting the energy lost when the ejector throttle (nozzle) is depressurized and sucking the refrigerant on the refrigerant evaporator side to ensure the flow rate of refrigerant flowing through the refrigerant evaporator. .

  Therefore, in the state where the high-low pressure difference becomes small as described above, the absolute amount of energy that can be recovered is insufficient, and the flow rate of the refrigerant evaporator cannot be secured. That is, the blowing temperature rises and the cooling capacity cannot be secured. As a result, for example, the blowing temperature of 3 ° C. cannot be secured at the time of dehumidifying heating, and there is a problem that window fogging cannot be cleared quickly. The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a refrigeration capable of preventing performance deterioration due to insufficient refrigerant flow at a low load of the ejector cycle (in a low temperature inside air mode). To provide a cycle device.

In order to achieve the above object, the present invention employs the following technical means. That is, in the first reference example to be described later, the control means (10) allows the discharge pressure (Ph) detected by the discharge pressure detection means (8) to be reduced by the ejector (3) because the high-low pressure difference becomes very small. When the loss energy is reduced and the normal control is performed, the variable throttle means (7) is excessively throttled and the flow rate on the drive flow side is reduced, resulting in a shortage of the flow rate on the suction flow side. ), If the pressure is lower than the first predetermined pressure (P1) indicating that the load is lower than the necessary capacity, the reduction in driving flow is small and the recoverable pressure loss energy can be secured. The variable throttle means (7) is optimally controlled by normal control so that a sufficient flow rate can be flowed and the required coefficient of performance can be secured in the refrigerant evaporator (6) even if the coefficient of performance (COP) is not maximum. Controls on the side opened than the control state, the discharge pressure (Ph) is so as to return to the normal control After a second predetermined pressure (P2) higher.

  FIG. 4 is a graph showing an optimum discharge pressure control line (control line that maximizes the coefficient of performance COP of the ejector cycle) with respect to the refrigerant temperature (Tgc) at the outlet of the refrigerant radiator (2). That is, if the discharge pressure (Ph) is equal to or higher than the first predetermined pressure (P1), the refrigerant temperature detecting means (9) detects the refrigerant temperature (Tgc) at the outlet of the refrigerant radiator (2) as the normal control mode, The optimum high pressure (Pe) corresponding to the refrigerant temperature (Tgc) is compared with the actual discharge pressure (Ph), and the variable throttle of the ejector (3) is set so that the discharge pressure (Ph) is the same as the optimum high pressure (Pe). The throttle opening is adjusted by means (7).

However, according to the first reference example , if the discharge pressure (Ph) is equal to or lower than the first predetermined pressure (P1), it is determined that the refrigeration cycle is in a low load state, and the variable throttle means ( 7) The throttle opening is set to be larger than the so-called optimum high-pressure control state, which is controlled to open side (full opening or a predetermined opening close to substantially full opening). Then, when the output of the discharge pressure detection means (8) rises above the second predetermined pressure (P2), the normal control mode is restored. Specifically, an electromagnetic proportional type differential pressure type pilot valve as shown in FIG. 2 is used for the ejector (3), and the throttle opening is adjusted by adjusting the control current.

  FIG. 5 is a graph showing the relationship between the throttle opening of the ejector (3), the coefficient of performance (COP), and the cooling capacity. When the discharge pressure (Ph) is equal to or lower than the first predetermined pressure (P1), the high-low pressure difference is very small, and the pressure loss energy that can be recovered by the ejector (3) is small. In this state, when the discharge pressure (Ph) is controlled to the optimum high pressure control line shown in FIG. 4 by the variable throttle means (7) of the ejector (3) as a normal control, the high pressure at which the coefficient of performance (COP) is maximized. In order to maintain the flow rate, the throttle flow becomes too narrow (position a in FIG. 5), the flow rate on the driving flow side decreases, and as a result, the flow rate on the suction flow side (refrigerant evaporator (6) side) is completely insufficient. As a result, the refrigerant evaporator (6) will fall below the required cooling capacity.

  However, when the discharge pressure (Ph) is equal to or lower than the first predetermined pressure (P1) as described above, the variable throttle means (7) is controlled to be fully opened or to a predetermined opening close to substantially fully opened (in FIG. (position b), since there is no decrease in the driving flow, the recoverable decompression loss energy can be secured reasonably, so that the suction flow side can also flow a sufficient flow rate. That is, even if the coefficient of performance (COP) is not the maximum, the refrigerant evaporator (6) can ensure the necessary cooling capacity (see FIG. 5).

Further, in the second reference example described later, the control means (10) is configured such that the variable throttle means (7) when the refrigerant temperature (Tgc) detected by the refrigerant temperature detection means (9) is equal to or lower than the first predetermined temperature (T1). controls on the side to open the refrigerant temperature (Tgc) is so as to return to the normal control When a second predetermined temperature (T2) or more. In the first reference example described above, the switching between the normal control and the driving flow increase operation is determined based on the discharge pressure (Ph), whereas according to the second reference example , the refrigerant heat dissipation. This is determined by the refrigerant temperature (Tgc) at the outlet of the vessel (2). Also by this, the same effect as the first reference example can be obtained.

Therefore , in the first aspect of the present invention, when the refrigerant temperature (Tgc) detected by the refrigerant temperature detecting means (9) is equal to or lower than the first predetermined temperature (T1), the control means (10) can adjust the variable throttle means (7). ) Is opened, and when the refrigerant temperature (Tgc) becomes equal to or higher than the second predetermined temperature (T2), the variable throttle means (7) is made into a refrigerant-filled temperature type mechanical variable throttle mechanism. In addition, a shape memory member (51a) for energizing the throttle opening in the direction to close the throttle opening is installed in the temperature sensing part (51), and flows out from the refrigerant radiator (2) to circulate around the temperature sensing part (51). When the refrigerant temperature (Tgc) to be performed is equal to or lower than the predetermined temperature (T1), the squeezing opening is opened by reducing the urging force by the shape memory member (51a).

According to the invention described in claim 1, by a mechanical variable throttle mechanism of the refrigerant sealed thermostatic, and performs control to mechanically. A shape memory member (51a), specifically a shape memory spring, for example, is installed inside the temperature sensing part (51) for sensing the refrigerant temperature (Tgc) at the outlet of the refrigerant radiator (2), and the refrigerant temperature (Tgc) is When the temperature is equal to or higher than the predetermined temperature (T1), the diaphragm is closed in the direction in which the diaphragm is closed while the urging force of the shape memory spring is applied. Set the density.

  When the refrigerant temperature (Tgc) becomes equal to or lower than the predetermined temperature (T1), the urging force of the shape memory spring disappears and acts in the direction of opening the throttle. Thus, by configuring as a mechanical type, control by the refrigerant temperature detection means (9) and the control means (10) becomes unnecessary.

In the second aspect of the present invention, the mechanical variable throttle mechanism of the refrigerant-filled temperature type is a capillary temperature sensing type, and the heating and cooling means (31) is provided in the temperature sensing part (51b), and the temperature sensing part ( The throttle opening degree is controlled by heating or cooling 51b) by the heating / cooling means (31). According to the second aspect of the present invention, as shown in FIGS . 9 and 10, the temperature sensing portion (51b) at the capillary tip is brought into close contact with the refrigerant pipe at the outlet of the refrigerant radiator (2), and the temperature sensing portion ( The heating / cooling means (31), specifically, for example, a Peltier element is brought into close contact with 51b) at the same time.

Then, by applying a voltage to the Peltier element, the Peltier element is cooled to lower the internal pressure of the temperature sensing part (51b), thereby controlling the throttle opening in the opening direction. In rapid cooling, the throttle opening is controlled in the closing direction by applying a voltage with a reverse polarity to heat the Peltier element and increase the internal pressure of the temperature sensing part (51b). Thus, the control according to the first aspect of the present invention is performed. Thereby, a refrigerant temperature detection means (9) becomes unnecessary.

In the invention according to claim 3 , the control means (10) calculates the first throttle opening (S1) of the variable throttle means (7) for setting the discharge pressure (Ph) to the optimum high pressure (Pe). And calculating the second throttle opening (S2) of the variable throttle means (7) from the refrigerant temperature (Tgc) based on the predetermined throttle opening map with respect to the refrigerant temperature (Tgc) stored and held therein , Compared with the two throttle openings (S1 , S2), the larger opening is selected and executed.

In the first aspect of the invention described above, it is determined whether or not the engine is in a low load state from the discharge pressure (Ph) or the refrigerant temperature (Tgc), and if the load is low, the throttle opening is controlled to open. However, according to the third aspect of the present invention, the predetermined throttle opening degree map for the refrigerant temperature (Tgc) for ensuring the cooling capacity is stored and held in the control means (10). Comparing the throttle opening (S1) for setting the optimum high pressure (Pe) at the optimum discharge pressure control line in the control with the throttle opening (S2) derived from the predetermined throttle opening map, the larger one The opening is selected and executed. As a result, a state in which the cooling capacity is always higher is selected.

In the invention according to claim 4 , the air-conditioning air is blown to the refrigerant evaporator (6), and the control means (10) has a predetermined driving voltage for the air-blowing means (67). When the driving voltage is lower than the predetermined value, the predetermined throttle opening map is changed in the direction of decreasing the throttle opening. It is said.

According to the fourth aspect of the present invention, it can be determined whether the load of the refrigerant evaporator (6) is high or low depending on whether the drive voltage of the blower means (67) is higher or lower than a predetermined value. Accordingly, the predetermined throttle opening map is corrected in the direction in which the throttle opening increases or the throttle opening decreases. Thereby, the cooling capacity according to the level of load is further set.

According to the fifth aspect of the present invention, the vehicle air conditioner includes the inside air temperature detecting means (83) for detecting the temperature of the passenger compartment air and the outside air temperature detecting means (84) for detecting the temperature of the air outside the passenger compartment. In addition to applying the refrigeration cycle apparatus to (61), the control means (10) has a predetermined air temperature to the refrigerant evaporator (6) detected by the inside air temperature detecting means (83) or the outside air temperature detecting means (84). If it is higher than the value, the predetermined throttle opening map is changed in the direction of increasing the throttle opening, and if the blown air temperature is lower than the predetermined value, the predetermined throttle opening map is changed in the direction of decreasing the throttle opening. It is a feature.

According to the fifth aspect of the present invention, it can be determined whether the load on the refrigerant evaporator (6) is high or low depending on whether the temperature of the blown air to the refrigerant evaporator (6) is higher or lower than a predetermined value. The predetermined throttle opening map is corrected in the direction in which the throttle opening increases or the throttle opening decreases in accordance with the level of the load. This also sets the cooling capacity according to the load level. In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(First Reference Example )
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 relate to a first reference example of the present invention, FIG. 1 is a circuit diagram showing a schematic configuration of a refrigeration cycle in a vehicle air conditioner, and FIG. 2 is a cross-sectional view showing a structural example of an ejector 3. It is.

The refrigeration cycle of the vehicle air conditioner of the present reference example is an ejector cycle in which the compressor 1, the gas cooler 2, the ejector 3, and the gas-liquid separator 4 are connected in a ring shape by a refrigerant pipe. Further, in this ejector cycle, the liquid refrigerant outlet portion of the gas-liquid separator 4 and the low pressure inlet portion of the ejector 3 are connected by a bypass pipe, and in the middle of the bypass pipe, a decompressor 5 and an evaporator ( (Refrigerant evaporator) 6 is installed.

Here, the refrigeration cycle of the present reference example uses, for example, a refrigerant mainly composed of carbon dioxide (CO2) having a low critical temperature, and the high pressure of the refrigerant is equal to or higher than the critical pressure of the refrigerant. It is comprised by. In this supercritical vapor compression ejector cycle, the refrigerant temperature at the inlet of the gas cooler 2, that is, the discharge temperature of the refrigerant discharged from the outlet of the compressor 1 is increased to about 150 ° C. by increasing the refrigerant pressure on the high pressure side. it can. When the refrigerant flowing into the gas cooler 2 is pressurized to a critical pressure or higher by the compressor 1, the refrigerant does not liquefy even if the heat is radiated by the gas cooler 2.

  The compressor 1 is rotationally driven by a driving source such as an engine (not shown) or an electric motor (not shown) mounted in an engine room of the vehicle, compresses the refrigerant gas sucked into the compressor 1, and converts the high-temperature and high-pressure refrigerant gas to the gas cooler 2 side. In the refrigerant compressor, the refrigerant gas sucked from the refrigerant gas outlet of the gas-liquid separator 4 is temporarily compressed to a high temperature and high pressure up to a critical pressure or higher under the use conditions and discharged. In addition, the gas cooler 2 is installed in a place where it is easy to receive traveling wind in the engine room of the vehicle, and heats the refrigerant gas discharged from the discharge port of the compressor 1 and the outside air sent by a cooling fan or the like (not shown). This is a refrigerant radiator that exchanges heat to dissipate refrigerant gas.

  The ejector 3 includes a high-pressure inlet portion 11, a low-pressure inlet portion 12, a nozzle 13, a mixing portion 14, a diffuser portion 15, and the like. When the refrigerant flowing in from the high pressure inlet 11 passes through the nozzle 13, the ejector 3 draws the refrigerant from the low pressure inlet 12 of the ejector 3 by using the pressure drop around the refrigerant jetted from the nozzle 13 at a high speed. The

As a result, the refrigerant sucked from the low pressure inlet 12 and the refrigerant blown from the nozzle 13 are mixed in the mixing unit 14, diffused in the diffuser unit 15 and increased in pressure, and then discharged from the discharge port (outlet part) of the ejector 3. ) To the gas-liquid separator 4. The ejector 3 of this reference example is integrally provided with a variable throttle mechanism 7 that changes the throttle diameter (nozzle outlet diameter) in accordance with load fluctuations.

  The gas-liquid separator 4 is an accumulator that gas-liquid separates the refrigerant decompressed by the ejector 3. Further, the decompression device 5 is a fixed throttle such as a capillary tube or an orifice that reduces the pressure of the liquid refrigerant flowing from the liquid refrigerant outlet portion of the gas-liquid separator 4 to form a gas-liquid two-phase refrigerant, or a temperature type or electric type. This is a variable aperture. The evaporator 6 evaporates and evaporates the refrigerant decompressed by the decompression device 5 by heat exchange with outside air or inside air that is blown by a blower fan (not shown), and causes the refrigerant gas to be supplied to the compressor 1 via the ejector 3. It is a refrigerant evaporator to supply.

  A bypass passage 21 that branches from the upstream side of the high-pressure inlet 11 of the ejector 3, an orifice 22 provided on the branch point side of the bypass passage 21, and a junction point side of the bypass passage 21 relative to the orifice 22. A pressure control valve (hereinafter abbreviated as a control valve) 23 as an electromagnetic actuator, and the nozzle of the ejector 3 according to the pressure difference between the refrigerant pressure in the bypass passage 21 and the refrigerant pressure in the high-pressure inlet 11 of the ejector 3 13 includes a needle valve 18 or the like that changes the throttle diameter (nozzle outlet diameter).

  The orifice 22 is a fixed throttle for forming an intermediate pressure between the control valve 23 and a high pressure and a low pressure. As shown in FIG. 2, the bypass flow path 21 branches the refrigerant flow path (high pressure side refrigerant flow path 20) upstream of the high pressure inlet 11 of the ejector 3, passes through the orifice 22 and the control valve 23, and the evaporator. 6 is a refrigerant flow path that merges between the outlet portion 6 and the low pressure inlet portion 12 of the ejector 3.

  The bypass passage 21 has a high-pressure introduction path 24 that branches from a branch point upstream of the high-pressure inlet portion 11 of the ejector 3 and a low-pressure introduction path 25 that joins a junction point upstream of the low-pressure inlet portion 12 of the ejector 3. And an intermediate pressure portion 26 between the orifice 22 and the control valve 23, which are formed in the housings 16 and 17 of the ejector 3. The orifice 22 is provided in the whole or a part of the high pressure introduction path 24.

In this reference example , a branch point of the bypass channel 21 is provided in the middle of the high-pressure side refrigerant channel 20 for sending the refrigerant flowing out of the gas cooler 2 to the high-pressure inlet 11 of the ejector 3, and the bypass channel 21 is joined. The point is provided in the middle of the low-pressure side refrigerant flow path 27 for sending the refrigerant flowing out from the outlet of the evaporator 6 to the low-pressure inlet 12 of the ejector 3. Thereby, the high pressure introduced into the high pressure introduction passage 24 of the bypass passage 21 is introduced from the high pressure side refrigerant passage 20, and the low pressure introduced into the low pressure introduction passage 25 of the bypass passage 21 is reduced to the low pressure side refrigerant passage. 27.

  The control valve 23 constitutes an actuator that drives the needle valve 18 in the left-right direction in the drawing, and adjusts the opening area (valve opening) of the low-pressure introduction passage 25 of the bypass passage 21 as shown in FIG. A pilot valve 23a for driving, an electromagnetic coil 23b for driving the pilot valve 23a in the valve closing direction, and a pilot valve biasing means (not shown) such as a spring for biasing the pilot valve 23a in the valve opening direction. And the control valve 23 is comprised so that the opening degree of the pilot valve 23a may be changed according to the electrical signal applied to the electromagnetic coil 23b from the control apparatus (control means) 10 mentioned later.

  The needle valve 18 changes the throttle diameter (nozzle outlet portion diameter, opening area) of the nozzle 13 of the ejector 3 to change the nozzle 13 of the ejector 3 to a variable nozzle. The needle valve 18 has a higher pressure than the high pressure inlet portion 11 of the ejector 3. The pressure difference between the refrigerant pressure in the first pressure chamber 28 into which the refrigerant is introduced and the refrigerant pressure (intermediate pressure) in the second pressure chamber 26 formed between the orifice 22 and the pilot valve 23a of the control valve 23 Accordingly, the proportional differential pressure valve changes the throttle diameter (nozzle outlet diameter, opening area) of the nozzle 13 of the ejector 3.

  Further, the needle valve 18 has a small diameter portion having a small outer diameter and a bowl-shaped large diameter portion having an outer diameter larger than the small diameter portion, and a passage hole 29 on the high pressure inlet portion 11 side of the ejector 3 inside. The orifice 22 communicating with the second pressure chamber 26 is formed. The first and second pressure chambers 28 and 26 are formed between the illustrated left end surface of the housing 17 of the ejector 3 and the recessed portion formed on the illustrated right end surface of the housing 16. The first pressure chamber 28 is defined on the right side of the large diameter portion of the needle valve 18 and the second pressure chamber 26 is illustrated on the left side of the large diameter portion of the needle valve 18. Yes.

  The needle valve 18 is attached to the pressure difference (differential pressure) of the refrigerant pressure in the first and second pressure chambers 28 and 26 and the needle valve 18 in the direction of narrowing the nozzle outlet diameter (reducing the opening area). The spring 16 of the return spring 19 is slidable in the left and right directions in the housings 16 and 17, and the throttle diameter (nozzle outlet) of the nozzle 13 of the ejector 3 depends on the position of the needle valve 18 in the left and right direction in the figure. The diameter is changed.

  Here, the refrigeration equipment of the refrigeration cycle, in particular, the control device 10 (hereinafter referred to as ECU) that controls the electromagnetic coil 23b of the control valve 23 includes functions such as a CPU, ROM, RAM, and I / O port. The microcomputer itself has a well-known structure.

  A discharge pressure sensor (discharge pressure detecting means) 8 for detecting the discharge pressure Ph of the refrigerant discharged from the discharge port of the compressor 1 and flowing into the gas cooler 2 and the refrigerant temperature Tgc flowing out from the outlet of the gas cooler 2 are detected. The sensor signal from the refrigerant temperature sensor (refrigerant temperature detection means) 9 is A / D converted by an input circuit (A / D conversion circuit) (not shown) and then input to the microcomputer.

  Then, as a normal operation, the ECU 10 calculates the load fluctuation or load state of the refrigeration cycle from the refrigerant pressure Ph detected by the discharge pressure sensor 8 and the refrigerant temperature Tgc detected by the refrigerant temperature sensor 9, and the calculated load A drive signal corresponding to the fluctuation or load state is applied to the electromagnetic coil 23 b of the control valve 23.

In this reference example , the ECU 10 determines that the load is larger as the refrigerant pressure Ph detected by the discharge pressure sensor 8 or the refrigerant temperature Tgc detected by the refrigerant temperature sensor 9 is larger, and the larger the load is. The drive signal is sent to the electromagnetic coil of the control valve 23 so that the throttle diameter (nozzle outlet portion diameter, opening area) of the nozzle 13 of the ejector 3 is increased, that is, the pilot valve 23a is moved to the left and the intermediate pressure is lowered. 23b.

Next, the operation of the refrigeration cycle of this reference example will be briefly described with reference to FIGS. 1 and 2. The refrigerant gas that has been compressed by the compressor 1 and has become high-temperature and high-pressure flows into the gas cooler 2 from the inlet of the gas cooler 2. And when passing through the gas cooler 2, the outside air is deprived of heat and cooled.

  The refrigerant flowing out from the outlet of the gas cooler 2 passes through the high-pressure side refrigerant flow path 20, passes through the passage hole 29 formed in the small diameter portion of the needle valve 18 from the high-pressure inlet 11 of the ejector 3, and the nozzle 13. Flows in. The refrigerant that has flowed into the nozzle 13 is reduced in pressure when passing through the nozzle 13, and is blown into the mixing unit 14 from the outlet of the nozzle 13. The pressure is increased when passing through the mixing unit 14 and the diffuser unit 15.

  At this time, the gas refrigerant is sucked from the outlet portion of the evaporator 6 to the low pressure inlet portion 12 of the ejector 3 by utilizing the pressure drop around the refrigerant jetted from the nozzle 13 at high speed. As a result, the refrigerant ejected from the nozzle 13 at high speed and the refrigerant flowing in from the low-pressure inlet portion 12 are efficiently mixed in the mixing portion 14 and then diffused in the diffuser portion 15. The gas-liquid two-phase refrigerant that has flowed out of the diffuser section 15 flows into the gas-liquid separator 4 and is gas-liquid separated. Thereafter, the gas refrigerant in the gas-liquid separator 4 is sucked into the compressor 1 by the suction input of the compressor 1 from the gas refrigerant outlet portion.

  Also, the liquid refrigerant accumulated at the bottom of the gas-liquid separator 4 flows out from the liquid refrigerant outlet of the gas-liquid separator 4 by the suction action of the low-pressure inlet 12 of the ejector 3 and flows into the decompressor 5. When passing through the decompression device 5, it is decompressed and expanded to become a gas-liquid two-phase refrigerant and flows into the evaporator 6 from the inlet of the evaporator 6. The refrigerant flowing into the evaporator 6 is evaporated and evaporated by exchanging heat with, for example, air flowing in the air conditioning duct of the vehicle air conditioner, and then sucked into the low pressure inlet 12 of the ejector 3, as described above. 3 is mixed with the refrigerant blown out from the outlet of the nozzle 13 in the mixing section 14.

  Here, a part of the refrigerant flowing into the bypass flow path 21 branched from the upstream side of the high-pressure inlet 11 of the ejector 3 is decompressed when passing through the orifice 22. This refrigerant is further depressurized to the same pressure as the low pressure inlet 12 of the ejector 3 according to the set position of the pilot valve 23 a of the control valve 23, and is led out to the low pressure inlet 12 of the ejector 3. The refrigerant flow (high pressure) on the high pressure inlet 11 side of the ejector 3 in the second pressure chamber 26 between the orifice 22 and the pilot valve 23a of the control valve 23 is caused by the refrigerant flow flowing in the bypass passage 21. And the refrigerant pressure (low pressure) on the low pressure inlet 12 side of the ejector 3 is created.

  The intermediate pressure, which is the refrigerant pressure in the second pressure chamber 26, increases as the opening of the pilot valve 23a of the control valve 23 decreases, that is, as the position of the pilot valve 23a moves to the right in the figure. Conversely, as the opening of the pilot valve 23a of the control valve 23 increases, that is, as the position of the pilot valve 23a moves to the left in the figure, the intermediate pressure, which is the refrigerant pressure in the second pressure chamber 26, decreases. .

  The needle valve 18 is subjected to high pressure (refrigerant pressure in the high-pressure inlet 11 of the ejector 3) from the first pressure chamber 28 and back pressure (intermediate pressure) from the second pressure chamber 26. A pressure difference (differential pressure) is generated on the right and left sides of the large diameter portion of the valve 18. The control position (movement amount, lift amount) of the needle valve 18, that is, the throttle diameter (nozzle outlet portion diameter, opening area) of the nozzle 13 of the ejector 3 is determined by this differential pressure and the panel spring of the return spring 19.

  Note that the control position of the needle valve 18 is such that the opening degree of the pilot valve 23a of the control valve 23 is changed according to the load fluctuation or load state, and the refrigerant pressure (high pressure) on the high pressure inlet 11 side of the ejector 3 is changed. By changing the intermediate pressure between the refrigerant pressure (low pressure) on the low pressure inlet 12 side of the ejector 3, an arbitrary control position can be obtained.

  Therefore, at the time of high load such as rapid cooling in summer, that is, when the load of the refrigeration cycle is large, the pilot valve 23a of the control valve 23 moves to the left in the figure and the opening degree becomes large, and the inside of the second pressure chamber 26 increases. The intermediate pressure, which is the refrigerant pressure, decreases. As a result, the needle valve 18 moves to the left in the figure, the throttle diameter (nozzle outlet diameter, opening area) of the nozzle 13 of the ejector 3 increases, and the amount of refrigerant circulating in the refrigeration cycle increases.

  In addition, when the load is low such as dehumidification in winter, that is, when the load of the refrigeration cycle is small, the pilot valve 23a of the control valve 23 moves to the right in the drawing and the opening degree decreases, and the refrigerant pressure in the second pressure chamber 26 decreases. The intermediate pressure is increased. Thereby, the needle valve 18 moves to the right in the drawing, the throttle diameter (nozzle outlet portion diameter, opening area) of the nozzle 13 of the ejector 3 is reduced, and the refrigerant circulation amount in the refrigeration cycle is reduced.

Next, the ejector aperture control in the first reference example will be described based on the flowchart of FIG. First, in step S1, the refrigerant discharge pressure Ph from the compressor 1 detected by the discharge pressure sensor 8 is taken. In step S2, it is determined whether or not the discharge pressure Ph is equal to or lower than a preset first predetermined pressure P1.

  If the determination result is YES and the discharge pressure Ph is lower than the first predetermined pressure P1, the operation of increasing the drive flow by opening the throttle diameter of the nozzle 13 in steps S3 to S5 described below is performed. When the optimum high pressure control of the normal control in steps S6 to 10 described in Step S6 is performed and the determination result in Step S2 is NO and the discharge pressure Ph is higher than the first predetermined pressure P1, the steps S6 to S10 described later are performed. Only the optimum high-pressure control of normal control is performed.

  As an operation for increasing the driving flow, first, in step S3, a control signal is sent to the variable aperture mechanism 7 so that the aperture diameter of the nozzle 13 is fully opened or substantially opened. As a result, the flow rate on the drive flow side increases and the decompression loss energy that can be recovered by the ejector 3 also increases, so that a sufficient flow rate can also flow on the suction flow side. In this state, the refrigerant discharge pressure Ph from the compressor 1 detected by the discharge pressure sensor 8 is again taken in step S4. In step S5, it is determined whether or not the discharge pressure Ph is equal to or higher than a preset second predetermined pressure P2.

  If the determination result is NO and the discharge pressure Ph is still lower than the second predetermined pressure P2, the operations of steps S3 to S5 are repeated. Then, when the vehicle cooling load is changed or the like, the determination result in step S5 is YES, and the discharge pressure Ph becomes higher than the second predetermined pressure P2, the optimum of normal control in the next steps S6 to 10 High pressure control is performed.

  As the optimum high pressure control of the normal control, first, in step S6, the refrigerant temperature Tgc at the outlet of the gas cooler 2 detected by the refrigerant temperature sensor 9 is taken. In step S7, the optimum high pressure Pe is calculated from the taken-in refrigerant temperature Tgc based on the optimum high pressure control map stored and held in the control device 10. In the next step S8, the discharge pressure Ph is taken in again, and it is determined whether or not it is the same as the optimum high pressure Pe calculated in step S9.

  If the determination result is NO and the discharge pressure Ph is still higher than the optimum high pressure Pe, the operation proceeds to step S10a to open the throttle diameter of the nozzle 13 and lower the discharge pressure Ph. Further, even if the determination result is the same NO, when the discharge pressure Ph is lower than the optimum high pressure Pe, the operation proceeds to step S10b to perform an operation of closing the throttle diameter of the nozzle 13 and increasing the discharge pressure Ph. Then, the operations in steps S6 to S10 are repeated, and the variable throttle mechanism 7 is controlled so that the determination result in step S9 is YES and the discharge pressure Ph becomes the optimum high pressure Pe.

Next, features of this reference example will be described. When the discharge pressure Ph detected by the discharge pressure sensor 8 is equal to or lower than the first predetermined pressure P1, the control device 10 controls the variable throttle mechanism 7 to open, and normally when the discharge pressure Ph becomes equal to or higher than the second predetermined pressure P2. Return to control.

  FIG. 4 is a graph showing an optimum discharge pressure control line (control line that maximizes the coefficient of performance COP of the ejector cycle) with respect to the refrigerant temperature Tgc at the gas cooler 2 outlet. That is, if the discharge pressure Ph is equal to or higher than the first predetermined pressure P1, the refrigerant temperature sensor 9 detects the refrigerant temperature Tgc at the outlet of the gas cooler 2 as the normal control mode, and the optimum high pressure Pe corresponding to the refrigerant temperature Tgc and the actual discharge The throttle opening is adjusted by the variable throttle mechanism 7 of the ejector 3 so that the discharge pressure Ph is equal to the optimum high pressure Pe.

However, in this reference example , if the discharge pressure Ph is equal to or lower than the first predetermined pressure P1, it is determined that the refrigeration cycle is in a low load state, and the variable throttle mechanism 7 side of the ejector 3 is opened (fully opened or substantially fully opened). To a close predetermined opening). The throttle opening is set to be larger than the so-called optimum high pressure control state. When the output of the discharge pressure sensor 8 rises to the second predetermined pressure P2 or higher, the normal control mode is restored. Specifically, an electromagnetic proportional type differential pressure type pilot valve as shown in FIG. 2 is used for the ejector 3, and the throttle opening is adjusted by adjusting the control current.

  FIG. 5 is a graph showing the relationship between the throttle opening of the ejector 3, the coefficient of performance COP, and the cooling capacity. When the discharge pressure Ph is equal to or lower than the predetermined pressure P1, the high-low pressure difference is very small, and thus the pressure loss energy that can be recovered by the ejector 3 is small. In such a state, when the discharge pressure Ph is controlled to the optimum high pressure control line shown in FIG. 4 by the variable throttle mechanism 7 of the ejector 3 as normal control, the throttle is set to maintain the high pressure at which the coefficient of performance COP is maximized. 5 (position a in FIG. 5), the flow rate on the drive flow side decreases, and as a result, the flow rate on the suction flow side (evaporator 6 side) becomes completely insufficient, and the evaporator 6 has a necessary cooling capacity. It will be less than.

  However, as described above, when the discharge pressure Ph becomes equal to or lower than the predetermined pressure P1, if the variable throttle mechanism 7 is fully opened or controlled to a predetermined opening degree that is almost fully open (position b in FIG. 5), the driving flow is reduced. Therefore, since the decompression loss energy that can be recovered can be secured, the suction flow side can also flow a sufficient flow rate. That is, even if the coefficient of performance COP is not the maximum, the evaporator 6 can ensure the necessary cooling capacity (see FIG. 5).

(Second reference example )
FIG. 6 is a flowchart of ejector aperture control in the second reference example of the present invention. First, in step S11, the refrigerant temperature Tgc at the outlet of the gas cooler 2 detected by the refrigerant temperature sensor 9 is taken. In step S12, it is determined whether or not the refrigerant temperature Tgc is equal to or lower than a preset first predetermined temperature T1.

If the determination result is YES and the refrigerant temperature Tgc is lower than the first predetermined temperature T1, the operation of increasing the drive flow by opening the throttle diameter of the nozzle 13 in steps S13 to S15 described below is performed. When the optimum high pressure control of the normal control in steps S6 to S10 described in the first reference example is performed, the determination result in step S13 is NO, and the refrigerant temperature Tgc is higher than the first predetermined temperature T1, the same as in the first reference example Further, only the optimum high pressure control of the normal control in steps S6 to S10 is performed.

  As an operation for increasing the driving flow, first, in step S13, a control signal is sent to the variable aperture mechanism 7 so that the throttle diameter of the nozzle 13 is fully opened or substantially opened. As a result, the flow rate on the drive flow side increases and the decompression loss energy that can be recovered by the ejector 3 also increases, so that a sufficient flow rate can also flow on the suction flow side. In this state, the refrigerant temperature Tgc at the outlet of the gas cooler 2 detected by the refrigerant temperature sensor 9 is again taken in step S14. In step S15, it is determined whether or not the refrigerant temperature Tgc is equal to or higher than a preset second predetermined temperature T2.

If the determination result is NO and the refrigerant temperature Tgc is still lower than the second predetermined temperature T2, the operations of steps S13 to S15 are repeated. Then, when the vehicle cooling load is changed, for example, when the determination result in step S15 is YES and the refrigerant temperature Tgc is higher than the second predetermined temperature T2, the optimum normal control in the next steps S6 to 10 is performed. High pressure control is performed. Since this has been described in the first reference example , description thereof is omitted here.

Next, features of this reference example will be described. When the refrigerant temperature Tgc detected by the refrigerant temperature sensor 9 is equal to or lower than the first predetermined temperature T1, the control device 10 controls the variable throttle mechanism 7 to open, and normally when the refrigerant temperature Tgc becomes equal to or higher than the second predetermined temperature T2. Return to control. In the first reference example described above, switching between the normal control and the driving flow increase operation is determined based on the discharge pressure Ph, whereas in the present reference example , the refrigerant temperature Tgc at the outlet of the gas cooler 2 is determined. Judgment is made. Also by this, the same effect as the first reference example described above can be obtained.

(First Embodiment)
7 and 8 show a first embodiment of the present invention, FIG. 7 is a circuit diagram showing a schematic configuration of a refrigeration cycle in a vehicle air conditioner, and FIG. 8 shows a structural example of the ejector 3. FIG. The refrigeration cycle in FIG. 1 assumed in the first and second reference examples described above has a configuration having an internal heat exchanger 30 for exchanging heat between the refrigerant sucked into the compressor 1 and the refrigerant flowing out of the gas cooler 2. Is different. Further, the ejector 3 is integrated with a mechanical pressure control valve 50 as a variable throttle mechanism.

  The pressure control valve 50 is a refrigerant-filled temperature type, and the structure thereof is a refrigerant (in this case) at a predetermined liquid density in a temperature-sensing part 51 that is a sealed space composed of a thin-film diaphragm 52. Is enclosed with carbon dioxide), the temperature sensing part 51 is exposed to the high-temperature refrigerant flowing out of the gas cooler 2, and the pressure Ph of the high-pressure refrigerant acts on the surface of the diaphragm 52 opposite to the sealed space. The needle-like valve element 53 is operated by utilizing the pressure difference between the pressure in the temperature sensing part 51, that is, in the sealed space, and the pressure Ph of the high-pressure refrigerant.

  At this time, the valve body 53 is displaced (operated) in the axial direction to adjust the throttle opening at the refrigerant inlet portion 13a of the nozzle 13 to control the high-pressure refrigerant pressure Ph, that is, the discharge pressure Ph of the compressor 1. In the temperature sensing part 51, the refrigerant and nitrogen having a density in the range from the saturated liquid density at O ° C. to the saturated liquid density at the critical point of the refrigerant (about 550 kg / m 3 in this embodiment) An inert gas such as a gas is enclosed.

  Thus, when the high-pressure refrigerant pressure Ph is in the supercritical region, the pressure Ph of the high-pressure refrigerant is controlled based on the refrigerant temperature Tgc on the outlet side of the gas cooler 2 so as to follow the isodensity line of 550 kg / m3. When the pressure Ph is in the condensation region, the pressure Ph of the high-pressure refrigerant is controlled so that the degree of supercooling of the refrigerant on the outlet side of the gas cooler 2 becomes a predetermined value.

  At this time, in the supercritical region, the relationship between the high-pressure side refrigerant temperature Tgc at which the COP (coefficient of performance) is maximum and the high-pressure refrigerant pressure Ph substantially coincides with the isodensity line of 550 kg / m3. Controlled to maintain high COP.

  Next, features of this embodiment will be described. In the present embodiment, in addition to the basic structure of the refrigerant-filled temperature type mechanical pressure control valve 50, the valve body 53 is urged in the temperature sensing portion 51 via the diaphragm 52 in the direction in which the throttle opening is closed. A memory spring (shape memory member) 51a is provided. When the refrigerant temperature Tgc flowing out from the gas cooler 2 and circulating around the temperature sensing unit 51 is equal to or lower than the predetermined temperature T1, the biasing force by the shape memory spring 51a is reduced so that the throttle opening is opened. ing.

In the present embodiment, the same control as that of the second reference example described above is mechanically performed by a mechanical variable throttle mechanism of a refrigerant filling temperature type. A shape memory spring 51a is installed inside the temperature sensing portion 51 for sensing the refrigerant temperature Tgc at the outlet of the gas cooler 2, and when the refrigerant temperature Tgc is equal to or higher than the predetermined temperature T1, the shape memory spring 51a is urged with the urging force working. Is set in the direction of closing the refrigerant, and the density of the refrigerant sealed in the temperature sensing portion 51 is set so that normal control can be performed in this state.

  When the refrigerant temperature Tgc becomes equal to or lower than the predetermined temperature T1, the urging force of the shape memory spring disappears, and the throttle operates. Thus, by configuring as a mechanical type, control by the refrigerant temperature sensor 9 and the control device 10 becomes unnecessary. The temperature sensing part 51 does not necessarily have to be integrated with the pressure control valve 50, and may have a structure in which a separate temperature sensing part 51 is connected as shown in FIG.

( Second Embodiment)
9 and 10 show a second embodiment of the present invention. FIG. 9 is a circuit diagram showing a schematic configuration of a refrigeration cycle in a vehicle air conditioner. FIG. 10 shows a structural example of the ejector 3. FIG. As shown in FIGS . 9 and 10, the refrigerant pressure temperature type mechanical pressure control valve 50 is configured in the same manner as in the first embodiment described above, but differs in that it is a capillary temperature sensitive type.

  Further, a Peltier element 31 as a heating / cooling means is provided in the temperature sensing part 51b at the tip of the capillary. The throttle opening is controlled by heating or cooling the temperature sensing portion 51b with the Peltier element 31. Specifically, the temperature sensing part 51b at the tip of the capillary is in close contact with the refrigerant pipe at the outlet of the gas cooler 2, and the Peltier element 31 is in close contact with the temperature sensing part 51b at the same time.

Then, by applying a voltage from the control device 10 to the Peltier element 31, the Peltier element 31 is cooled to lower the internal pressure of the temperature sensing portion 51b, thereby controlling the throttle opening in the opening direction. In rapid cooling, the throttle opening is controlled in the closing direction by applying a voltage with a reverse polarity to heat the Peltier element 31 and increase the internal pressure of the temperature sensing part 51b. In this way, the same control as in the first and second reference examples described above is performed. Thereby, the refrigerant temperature sensor 9 becomes unnecessary.

( Third embodiment)
FIG. 11 is a flowchart of ejector aperture control according to the third embodiment of the present invention. First, in step S21, the refrigerant temperature Tgc at the outlet of the gas cooler 2 detected by the refrigerant temperature sensor 9 is taken. In the next step S22, the optimum high pressure Pe is calculated from the taken-in refrigerant temperature Tgc based on the optimum high pressure control map stored and held in the control device 10. Further, in step S23, the refrigerant discharge pressure Ph from the compressor 1 detected by the discharge pressure sensor 8 is taken in, and in the next step S24, the first throttle opening for setting the discharge pressure Ph to the optimum high pressure Pe calculated in step S23. S1 is calculated.

  On the other hand, the control device 10 stores therein a predetermined throttle opening degree map for the refrigerant temperature Tgc. This is to determine a predetermined throttle opening with respect to the refrigerant temperature Tgc in order to ensure the cooling capacity, and FIG. 12 is a graph showing a setting example of the second throttle opening S2 with respect to the refrigerant temperature Tgc. In step S25, the second throttle opening S2 is calculated from the refrigerant temperature Tgc taken in step S21 based on a predetermined throttle opening map stored and held therein.

  In step S26, it is determined whether the previous first throttle opening S1 is larger than the current second throttle opening S2. If the determination result is YES and the first throttle opening S1 is large, the process proceeds to step S27a to execute the first throttle opening S1. Further, if the determination result in step S26 is NO and the second throttle opening S2 is larger, the process proceeds to step S27b to execute the second throttle opening S2.

  Next, features of this embodiment will be described. The control device 10 according to the present embodiment calculates a first throttle opening S1 of the variable throttle mechanism 7 for setting the discharge pressure Ph to the optimum high pressure Pe, and a predetermined throttle opening map for the refrigerant temperature Tgc stored and held therein. Based on the refrigerant temperature Tgc, the second throttle opening S2 of the variable throttle mechanism 7 is calculated, the first throttle opening S1 and the second throttle opening S1 are compared, and the larger opening is selected and executed. Yes.

In the first and second reference examples described above, it is determined from the discharge pressure Ph or the refrigerant temperature Tgc whether or not it is in a low load state, and if the load is low, control is performed to open the throttle opening. According to the embodiment, a predetermined throttle opening degree map with respect to the refrigerant temperature Tgc for ensuring the cooling capacity is stored in the control device 10 and the optimum high pressure Pe in the optimum discharge pressure control line in the normal control is The larger opening is selected and executed by comparing the opening S1 for opening and the opening S2 derived from the predetermined opening map. As a result, a state in which the cooling capacity is always higher is selected.

( Fourth embodiment)
FIG. 13 is a schematic diagram showing a schematic configuration of a vehicle air conditioner 61 to which the present refrigeration cycle apparatus according to the fourth embodiment of the present invention is applied. The vehicle air conditioner 61 is mounted on a vehicle equipped with a water-cooled engine. is there. First, in the air upstream portion of the air-conditioning casing 62 that forms the air flow path, an inside air inlet 63 for sucking air in the passenger compartment and an outside air inlet 64 for sucking air outside the passenger compartment are formed. A suction port switching door 65 for selectively opening and closing the suction ports 63 and 64 is provided. The suction port switching door 65 is switched open and closed by driving means such as a servo motor 66.

  A blower blower 67 (blower unit) is disposed at a downstream side portion of the suction port switching door 65, and air sucked from both the suction ports 63 and 64 by the blower blower 7 is supplied to each blower port described later. Air is blown toward 74-76. An evaporator 6 that is an air cooling unit and is one of the refrigeration cycle apparatuses is disposed on the air downstream side of the blower blower 67, and all of the air blown by the blower blower 67 passes through the evaporator 6. .

  A heater core 70 constituting air heating means is disposed on the air downstream side of the evaporator 6, and the heater core 70 heats air by using the cooling water of the engine (not shown) as a heat source. In addition, a bypass passage 72 that bypasses the heater core 70 is formed in the air conditioning casing 62, and the air volume ratio between the air volume passing through the heater core 70 and the air volume passing through the bypass passage 72 is adjusted on the air upstream side of the heater core 70. An air mix door 73 is provided. The opening ratio of the air mix door 73 is adjusted by a driving means such as a servo motor 86 to adjust the air volume ratio, thereby adjusting the blown air temperature.

  Further, at the most downstream part of the air conditioning casing 2, a face outlet 74 for blowing air-conditioned air to the upper body of the passenger in the vehicle interior, a foot outlet 75 for blowing air to the feet of the passenger in the passenger compartment, and the windshield A defroster outlet 76 and a plurality of outlets are formed for blowing air toward the inner surface. Further, a face door 78, a foot door 79, and a defroster door 80 as mode switching doors are disposed on the upstream side of the air outlets 74 to 76, and are driven in conjunction by driving means such as a servo motor 77. The air outlet mode is switched by opening and closing each air outlet.

  In addition to the control of the refrigeration cycle, the control device 10 controls the electromagnetic clutch / blower blower 67, the drive means such as the servo motors 66, 77, 86, and the like. The control device 10 includes a temperature setting means 82 for setting a desired vehicle interior temperature, an internal air temperature sensor (internal air temperature detection means) 83 for detecting the temperature in the vehicle interior, and an external air temperature sensor (for detecting the temperature of the outside air). An outside air temperature detecting means) 84, a solar radiation sensor 85 for detecting the amount of solar radiation entering the vehicle interior, a temperature sensor 69 for detecting the downstream temperature of the evaporator 6, a water temperature sensor 71 for detecting the temperature of the engine cooling water, A potentiometer 87 that is attached to the servo motor 86 and detects the opening degree of the air mix door 73 is connected to the input.

  The control device 10 drives an electromagnetic clutch that turns the compressor on and off, a motor controller (not shown) that drives the blower blower 67, and an inlet switching door 65 according to a predetermined procedure based on the input signals from the sensor group 88. A control signal is output to the servo motor 66 that drives the air mix door 73 and the servo motor 77 that drives the mode switching doors 78 to 80.

  Next, features of this embodiment will be described. First, in the present embodiment, a blower 67 that blows air for air conditioning to the evaporator 6 is provided, and the control device 10 displays a predetermined throttle opening map when the drive voltage of the blower 67 is higher than a predetermined value. When the drive voltage is lower than a predetermined value, the predetermined throttle opening map is changed in the direction of decreasing the throttle opening (from the solid line to the one-dot chain line direction in FIG. 12). It is variable.

Since it can be determined whether the load on the evaporator 6 is high or low depending on whether the drive voltage of the blower blower 67 is higher or lower than a predetermined value, the predetermined opening degree map is increased in the predetermined opening degree map according to the level of the load. The direction is corrected in the direction in which the throttle opening is reduced. Thereby, the cooling capacity according to the level of load is further set.
In the present embodiment, the refrigeration cycle apparatus is applied to a vehicle air conditioner 61 that includes an inside air temperature sensor 83 that detects the temperature of the passenger compartment air and an outside air temperature sensor 84 that detects the temperature of the air outside the passenger compartment. When the temperature of the blown air to the evaporator 6 detected by the inside air temperature sensor 83 or the outside air temperature sensor 84 is higher than a predetermined value, the control device 10 displays the predetermined throttle opening map in the direction in which the throttle opening increases (solid line in FIG. 12). When the temperature of the blown air is lower than a predetermined value, the predetermined throttle opening map is changed in the direction of decreasing the throttle opening (from the solid line to the one-dot chain line in FIG. 12).

  This is because whether the load on the evaporator 6 is high or low can be determined also depending on whether the temperature of the blown air to the evaporator 6 is higher or lower than a predetermined value. Or a direction in which the throttle opening is reduced. This also sets the cooling capacity according to the load level.

(Other embodiments)
The present invention can be applied not only to a supercritical cycle using carbon dioxide or the like as a refrigerant, but also to a refrigeration cycle (ejector cycle) using chlorofluorocarbon or other refrigerants. In addition, it is used for refrigeration cycles (ejector cycles) used not only in refrigeration cycles (ejector cycles) of vehicle air conditioners such as automobiles but also in electric water heaters (heat pump water heaters). Applicable. The first predetermined pressure P1 and the second predetermined pressure P2 or the first predetermined temperature T1 and the second predetermined temperature T2 in the reference example described above may be the same pressure and the same temperature.

In the first and second reference examples described above, the electromagnetic control valve 23 as an actuator for driving the needle valve 18 is constituted by a pilot valve urging means such as a pilot valve 23a , an electromagnetic coil 23b and a spring. However, a motor-driven control valve driven by a stepping motor or the like, a piezoelectric control valve, or a valve having a mechanical structure may be used as an actuator for driving the needle valve 18.

It is a circuit diagram which shows schematic structure of the refrigerating cycle in connection with the 1st reference example of this invention. It is sectional drawing which shows the structural example of the ejector 3 in connection with the 1st reference example of this invention. It is a flowchart figure of ejector aperture control in the 1st reference example of this invention. It is a graph which shows the optimal discharge pressure control line (control line in which the coefficient of performance COP of an ejector cycle becomes the maximum) with respect to gas cooler exit refrigerant | coolant temperature Tgc. It is a graph which shows the relationship between the throttle opening degree of the ejector 3, a coefficient of performance (COP), and cooling capacity. It is a flowchart figure of ejector aperture control in the 2nd reference example of this invention. It is a circuit diagram which shows schematic structure of the refrigerating cycle in connection with 1st Embodiment of this invention. It is sectional drawing which shows the structural example of the ejector 3 in connection with 1st Embodiment of this invention. It is a circuit diagram which shows schematic structure of the refrigerating cycle in connection with 2nd Embodiment of this invention. It is sectional drawing which shows the structural example of the ejector 3 in connection with 2nd Embodiment of this invention. It is a flowchart figure of ejector aperture control in 3rd Embodiment of this invention. It is a graph which shows the example of a setting of 2nd aperture opening S2 with respect to gas cooler exit refrigerant | coolant temperature Tgc. It is a schematic diagram which shows schematic structure of the vehicle air conditioner 61 to which this refrigeration cycle apparatus in 4th Embodiment of this invention is applied. It is a circuit diagram which shows schematic structure of the conventional refrigerating cycle. It is sectional drawing which shows the structural example of the conventional ejector 103. FIG. It is a graph which shows the relationship between the aperture diameter and blowing temperature in an expansion valve cycle. It is a graph which shows the relationship between the aperture diameter and blowing temperature in an ejector cycle.

Explanation of symbols

1 ... Compressor (refrigerant compressor)
2 ... Gas cooler (refrigerant radiator)
3 ... Ejector 4 ... Gas-liquid separator 6 ... Evaporator (refrigerant evaporator)
7. Variable aperture mechanism (variable aperture means)
8. Discharge pressure sensor (discharge pressure detection means)
9. Refrigerant temperature sensor (refrigerant temperature detection means)
10 ... Control device (control means)
DESCRIPTION OF SYMBOLS 11 ... High pressure inlet part 12 ... Low pressure inlet part 13 ... Nozzle 31 ... Peltier device (heating-cooling means)
51 ... temperature sensing part 51a ... shape memory member (shape memory spring)
67 ... Blower (blower)
83. Inside air temperature sensor (inside air temperature detecting means)
84 ... Outside air temperature sensor (outside air temperature detecting means)
Ph: Discharge pressure Pe: Optimal high pressure Tgc: Refrigerant temperature P1: First predetermined pressure P2: Second predetermined pressure T1: First predetermined temperature, predetermined temperature T2: Second predetermined temperature S1: First throttle opening S2: Second Aperture opening

Claims (5)

A gas-liquid separator (4) for gas-liquid separation of the refrigerant;
A refrigerant compressor (1) for compressing and discharging the refrigerant sucked from the gas-liquid separator (4);
A refrigerant radiator (2) for radiating the high-temperature and high-pressure refrigerant discharged from the refrigerant compressor (1);
A refrigerant evaporator (6) for evaporating the low-temperature and low-pressure refrigerant flowing from the gas-liquid separator (4);
A high-pressure inlet (11) connected downstream of the refrigerant radiator (2) in the refrigerant flow direction, and a low-pressure inlet (12) connected downstream of the refrigerant evaporator (6) in the refrigerant flow direction. ), And a nozzle (13) that ejects the refrigerant flowing in from the high-pressure inlet (11), and is ejected from the nozzle (13) by utilizing the pressure drop around the refrigerant ejected from the nozzle (13). An ejector (3) for increasing the pressure while mixing the refrigerant to be sucked and the refrigerant sucked from the low-pressure inlet (12) and discharging the refrigerant to the gas-liquid separator (4);
Variable throttle means (7) provided in the discharge refrigerant circuit of the refrigerant compressor (1) for controlling the pressure of the high-pressure refrigerant by controlling the throttle opening;
A discharge pressure detecting means (8) for detecting a discharge pressure (Ph) discharged by the refrigerant compressor (1);
Refrigerant temperature detecting means (9) for detecting the refrigerant temperature (Tgc) flowing out from the refrigerant radiator (2);
Control means (10) for controlling the operation of these refrigeration cycle equipment,
As the normal control, the control means (10) detects the refrigerant temperature (Tgc) by the refrigerant temperature detection means (9), and the discharge pressure (Ph) is optimum based on the optimum high-pressure control map stored in the inside. In the refrigeration cycle apparatus for controlling the variable throttle means (7) to be high pressure (Pe),
The control means (10) controls the variable throttle means (7) to open when the refrigerant temperature (Tgc) detected by the refrigerant temperature detection means (9) is equal to or lower than a first predetermined temperature (T1). When the refrigerant temperature (Tgc) is equal to or higher than the second predetermined temperature (T2), when returning to the normal control, the variable throttle means (7) is a mechanical variable throttle mechanism of a refrigerant sealed temperature type, The shape memory member (51a) that urges the temperature sensing portion (51) in the direction to close the throttle opening is installed, and the refrigerant flows out of the refrigerant radiator (2) and circulates around the temperature sensing portion (51). when the temperature (Tgc) of the predetermined temperature (T1) or less, the shape-memory member (51a) refrigeration cycle apparatus characterized that you operate in the direction of opening said throttle opening degree by decreasing the biasing force by. The refrigerant enclosing temperature type mechanical variable throttle mechanism is a capillary temperature sensing type, a heating / cooling means (31) is provided in the temperature sensing part (51b), and the temperature sensing part (51b) is provided in the heating / cooling means (31). The refrigeration cycle apparatus according to claim 1, wherein the throttle opening is controlled by heating or cooling in step (1) . A gas-liquid separator (4) for gas-liquid separation of the refrigerant;
A refrigerant compressor (1) for compressing and discharging the refrigerant sucked from the gas-liquid separator (4);
A refrigerant radiator (2) for radiating the high-temperature and high-pressure refrigerant discharged from the refrigerant compressor (1);
A refrigerant evaporator (6) for evaporating the low-temperature and low-pressure refrigerant flowing from the gas-liquid separator (4);
A high-pressure inlet (11) connected downstream of the refrigerant radiator (2) in the refrigerant flow direction, and a low-pressure inlet (12) connected downstream of the refrigerant evaporator (6) in the refrigerant flow direction. ), And a nozzle (13) that ejects the refrigerant flowing in from the high-pressure inlet (11), and is ejected from the nozzle (13) by utilizing the pressure drop around the refrigerant ejected from the nozzle (13). An ejector (3) for increasing the pressure while mixing the refrigerant to be sucked and the refrigerant sucked from the low-pressure inlet (12) and discharging the refrigerant to the gas-liquid separator (4);
Variable throttle means (7) provided in the discharge refrigerant circuit of the refrigerant compressor (1) for controlling the pressure of the high-pressure refrigerant by controlling the throttle opening;
A discharge pressure detecting means (8) for detecting a discharge pressure (Ph) discharged by the refrigerant compressor (1);
Refrigerant temperature detecting means (9) for detecting the refrigerant temperature (Tgc) flowing out from the refrigerant radiator (2);
Control means (10) for controlling the operation of these refrigeration cycle equipment,
As the normal control, the control means (10) detects the refrigerant temperature (Tgc) by the refrigerant temperature detection means (9), and the discharge pressure (Ph) is optimum based on the optimum high-pressure control map stored in the inside. In the refrigeration cycle apparatus for controlling the variable throttle means (7) to be high pressure (Pe),
The control means (10) calculates the first throttle opening (S1) of the variable throttle means (7) for setting the discharge pressure (Ph) to the optimum high pressure (Pe), and stores it in the memory. The second throttle opening (S2) of the variable throttle means (7) is calculated from the refrigerant temperature (Tgc) based on the predetermined throttle opening map with respect to the refrigerant temperature (Tgc), and the first and second throttle openings are calculated. A refrigeration cycle apparatus characterized in that the degree of opening (S1, S2) is compared and the larger opening is selected and executed . While provided with a blowing means (67) for blowing air for air conditioning to the refrigerant evaporator (6),
When the drive voltage of the air blowing means (67) is higher than a predetermined value, the control means (10) varies the predetermined throttle opening map in a direction in which the throttle opening increases, and the drive voltage is lower than the predetermined value. 4. The refrigeration cycle apparatus according to claim 3, wherein the predetermined throttle opening map is varied in a direction in which the throttle opening is reduced . 5. The refrigeration cycle apparatus is applied to a vehicle air conditioner (61) having an inside air temperature detecting means (83) for detecting the temperature of the passenger compartment air and an outside air temperature detecting means (84) for detecting the temperature of the air outside the passenger compartment. With
The control means (10) is configured to reduce the predetermined throttle when the temperature of air blown to the refrigerant evaporator (6) detected by the internal air temperature detection means (83) or the external air temperature detection means (84) is higher than a predetermined value. claim varied in the direction of increase of the throttle opening degree of the opening degree map, wherein if the blowing air temperature is lower than a predetermined value, characterized in that the variable to decrease direction of throttle opening degree of the predetermined throttle opening degree map 3. The refrigeration cycle apparatus according to 3 .

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