JP4665601B2 - Cycle using ejector - Google Patents

Description

The present invention relates to a cycle using an ejector having an ejector that serves as a refrigerant decompression unit and a refrigerant circulation unit, and more specifically, to suppress problems associated with intermittent control of compressor operation. It is.

Conventionally, a cycle using this type of ejector is known from Patent Document 1 and the like. In this Patent Document 1, the second evaporator is connected to the refrigerant downstream side of the ejector serving as the refrigerant decompression means and the refrigerant circulation means, and the gas-liquid separator is arranged on the refrigerant downstream side of the second evaporator, A cycle using an ejector in which a first evaporator is disposed between the liquid refrigerant outlet side of the gas-liquid separator and the refrigerant suction port of the ejector is disclosed.

According to the cycle using the ejector of Patent Document 1, the vapor pressure refrigerant discharged from the first evaporator is sucked using the pressure drop caused by the high-speed flow of the refrigerant at the expansion, and the refrigerant at the expansion is Since the speed energy is converted into pressure energy by the diffuser section (pressure increase section) to increase the refrigerant pressure (suction pressure), the driving power of the compressor can be reduced. For this reason, the operating efficiency of the cycle can be improved.

  Further, the heat absorption (cooling) action can be exhibited from separate spaces by the first and second evaporators or from the same space by the two evaporators. There is also a description that room cooling may be performed with two evaporators (see paragraph 0192 of Patent Document 1).

In FIGS. 27 and 29 to 38 of Patent Document 1, in the cycle using the ejector in which the evaporator (the first evaporator) is disposed only on the refrigerant suction port side of the ejector, the upstream portion of the ejector or the evaporation is shown. It is described that a mechanical or electric control valve is provided upstream of the vessel.

Among these control valves, the control valve upstream of the ejector controls the superheat degree of the refrigerant at the outlet of the evaporator or the high pressure by adjusting the opening, and the control valve upstream of the evaporator adjusts the opening. Describes that superheat degree control of the evaporator outlet refrigerant is performed.
Japanese Patent No. 3322263

By the way, the control valve described in Patent Document 1 controls the superheat degree of the refrigerant at the outlet of the evaporator or the high pressure control during the operation of the cycle using the ejector, and thus interlocks with the intermittent operation of the compressor. Thus, the refrigerant passage is not opened and closed.

  For this reason, even when the operation of the compressor is stopped, the control valve is maintained in a predetermined opening state. Therefore, when the operation of the compressor is stopped, a phenomenon in which the cycle high / low pressure is made uniform, that is, a pressure balance occurs. In the process of this pressure balance, a flow sound of the refrigerant passing through the nozzle portion of the ejector is generated. In particular, when the compressor is stopped, the compressor operating noise disappears and the environment is quiet, so the refrigerant flow noise in the nozzle portion becomes annoying.

  Further, according to the study by the present inventor, the liquid refrigerant returns to the compressor when the compressor is restarted after the operation is stopped, and there is a problem that the liquid compression of the compressor adversely affects the durable life of the compressor. It has been found.

  That is, when the internal temperature is cooled to a cryogenic temperature near -20 ° C, for example, as in a vehicle refrigeration system, it is necessary to lower the cycle low pressure to a low pressure corresponding to the cryogenic temperature near -20 ° C. For this reason, the cycle high / low pressure difference during operation of the compressor is very large.

  Therefore, a large amount of liquid refrigerant flows from the high-pressure side to the low-pressure side through the nozzle portion of the ejector in the process of pressure balance accompanying the stoppage of the operation of the compressor. At this time, the internal temperature has already been cooled to a very low temperature, the heat load of the evaporator is small, and the refrigerant is not sucked into the compressor suction side, so the refrigerant flowing into the low pressure side is on the downstream side of the ejector It accumulates as a liquid phase refrigerant in the gas-liquid separator and the evaporator.

  As a result, the liquid refrigerant may overflow from the gas-liquid separator at the next start-up of the compressor, and the liquid refrigerant may return to the compressor.

In addition, in the present applicant, first, in Japanese Patent Application No. 2004-290120, a branch passage branched from the branch point upstream of the ejector and connected to the refrigerant suction port of the ejector is provided, and a throttle mechanism is provided in the branch passage. And a first evaporator, and a cycle using an ejector in which a second evaporator is provided on the refrigerant downstream side of the ejector.

According to the cycle using the ejector of the prior application, the first evaporator is connected in parallel with the ejector, and the branch passage is provided with a throttle mechanism dedicated to the first evaporator. In comparison, there are advantages such as easy adjustment of the refrigerant flow rates of the first evaporator and the second evaporator.

In the cycle using the ejector of the prior application, a flow noise is generated by the refrigerant passing through the nozzle portion of the ejector and the throttle mechanism of the branch passage in the process of pressure balance when the operation of the compressor is stopped.

  In addition, when the internal temperature is cooled to an extremely low temperature of, for example, around −20 ° C. as in an in-vehicle refrigeration system, the heat load of the evaporator is reduced when the compressor is stopped. A phenomenon occurs in which refrigerant flows into and accumulates in the first and second evaporators. In this case, abnormal noise is generated when the refrigerant further flows into the staying liquid refrigerant in the first and second evaporators.

  Further, the liquid refrigerant accumulated in the first and second evaporators when the compressor is stopped is sucked into the compressor at the next start-up of the compressor, and the liquid refrigerant returns to the compressor.

In view of the above points, an object of the present invention is to suppress problems caused by intermittent control of compressor operation in a cycle using an ejector having a function of intermittently controlling compressor operation.

The present invention has been made to achieve the above object, and in the invention described in claim 1, a compressor (11) for sucking and compressing refrigerant,
A radiator (13) that radiates heat of the high-pressure refrigerant discharged from the compressor (11);
The radiator (13) has a refrigerant suction port (17b) for decompressing and expanding the refrigerant on the downstream side, and sucking the refrigerant into the interior by the high-speed refrigerant flow at the time of expansion, and from the refrigerant suction port (17b) An ejector (17) for mixing the suction refrigerant and the high-speed refrigerant flow, decelerating the mixed refrigerant flow and increasing the pressure of the refrigerant flow;
An evaporator (18) provided in a branch passage (19, 45) connected to the refrigerant suction port (17b);
On- off valve (16) provided on the upstream side of the evaporator (18) on the side of the refrigerant suction port (17b) and the ejector (17) as an opening / closing means capable of preventing the refrigerant from flowing into the evaporator (18) A passage opening and closing mechanism (17e) provided in itself;
Control means (25) for intermittently controlling the operation of the compressor (11),
Wherein said control means (25), said closing means (16,17E) to the closed state within the period of stopping the operation of the compressor (11), the refrigerant of the switching means (16,17E) upstream Inflow to the flow path on the ejector (17) side is prevented, and further, the on-off valve (16) is first returned from the closed state to the open state during the stop period of the compressor (11), and the pressure in the cycle The balance is executed, and then the compressor (11) is restarted after the passage opening / closing mechanism (17e) is delayed and returned to the open state .

  According to this, with the stop of the compressor (11) operation, the opening / closing means (16, 17e) can be closed to prevent the refrigerant from flowing into the evaporator (18). Therefore, since it can suppress that a liquid refrigerant accumulates in an evaporator (18) at the time of a compressor stop, it can suppress that the liquid refrigerant returns to a compressor at the time of the next compressor starting.

 Moreover, the refrigerant | coolant flow noise accompanying the refrigerant | coolant inflow to an evaporator (18) can be suppressed at the time of a compressor stop. Further, by preventing the refrigerant from flowing into the evaporator (18) when the compressor is stopped, it is possible to suppress an increase in pressure in the evaporator (18) when the compressor is stopped and to suppress an increase in the temperature of the evaporator (18).

According to a second aspect of the present invention, in the cycle using the ejector according to the first aspect, the evaporator on the refrigerant suction port (17b) side is provided as a first evaporator (18), and the ejector A cycle configuration in which the second evaporator (21) is provided on the downstream side of (17) can be employed.

In the cycle using the ejector according to claim 2 as in the invention according to claim 3, one common cooling target space is formed by the first evaporator (18) and the second evaporator (21). (23) may be cooled.

Further, in the cycle using the ejector according to claim 2, as in the invention according to claim 4, separate cooling target spaces are provided by the first evaporator (18) and the second evaporator (21). (23a, 23b) may be cooled.

In the cycle using the ejector according to any one of claims 1 to 4 as in the invention according to claim 5, it is correlated with the temperature of the cooling target space (23, 23a) of the evaporator (18). Temperature detecting means (24, 24a, 24b) for detecting a certain temperature,
The control means (25) may be configured to intermittently control the operation of the compressor (11) based on the temperature detected by the temperature detection means (24, 24a, 24b).

According to a sixth aspect of the present invention, in the cycle using the ejector according to any one of the first to fifth aspects, the control means (25) is arranged so that the compressor (11) is stopped prior to the stop of the compressor (11). The opening / closing means (16, 17e) is changed from the open state to the closed state, and the operation state of the compressor (11) is continued for a predetermined time in the closed state of the opening / closing means (16, 17e), and then the compressor (11) It is characterized by stopping.

  According to this, since the operating state of the compressor (11) continues for a predetermined time even after the opening / closing means (16, 17e) shifts to the closed state, the refrigerant on the low-pressure side of the cycle is sucked in during the operation of the compressor. Then, it can be moved to the high pressure side and can be held at the high pressure side (pump down operation). Thereby, the refrigerant | coolant amount which accumulates in an evaporator (18, 21) during a compressor stop period can be reduced much more effectively.

According to a seventh aspect of the present invention, in a cycle using the ejector according to any one of the first to sixth aspects, the opening / closing means (16, 17e) is disposed upstream of the open / close means (16, 17e), and the open / close means (16, 17e) having a throttle mechanism (15, 20, 20a) for reducing the pressure so that the upstream refrigerant enters a gas-liquid two-phase state.

  According to this, since the upstream refrigerant of the opening / closing means (16, 17e) contains a compressible gas-phase refrigerant, the opening / closing means (16, 17e) of the opening / closing means (16, 17e) is shifted to the closed state. A phenomenon (water hammer ring phenomenon) in which the upstream pressure rapidly increases can be suppressed.

In the invention according to claim 8, in the cycle using the ejector according to any one of claims 1 to 7, the ejector (17) and the on-off valve (16) are assembled as at least an integral part. It is characterized by being.

  According to this, by configuring the ejector (17) and the on-off valve (16) as an integral part in advance, both parts (16, 17) can be reduced in size and cost.

In the invention described in claim 9, a compressor (11) for sucking and compressing refrigerant,
A radiator (13) that radiates heat of the high-pressure refrigerant discharged from the compressor (11);
The radiator (13) has a refrigerant suction port (17b) for decompressing and expanding the refrigerant on the downstream side, and sucking the refrigerant into the interior by the high-speed refrigerant flow at the time of expansion, and from the refrigerant suction port (17b) An ejector (17) for mixing the suction refrigerant and the high-speed refrigerant flow, decelerating the mixed refrigerant flow and increasing the pressure of the refrigerant flow;
A first evaporator (21) for evaporating the refrigerant flowing out of the ejector (17);
A second evaporator (34) connected to a refrigerant passage for branching the refrigerant flow from the ejector (17) to the first evaporator (21) and evaporating the refrigerant flowing out of the ejector (17). When,
Open / close means (16, 17e) capable of preventing refrigerant from flowing into the ejector (17);
Control means (25) for intermittently controlling the operation of the compressor (11),
The control means (25) closes the opening / closing means (16, 17e) within a period during which the operation of the compressor (11) is stopped, and the refrigerant upstream of the opening / closing means (16, 17e) is discharged from the ejector (17 It features a cycle that uses an ejector that prevents it from flowing into the flow path on the) side.
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)
1 to 2 show a first embodiment of the present invention, and FIG. 1 shows an example in which a cycle 10 using an ejector according to the first embodiment is applied to a vehicle refrigeration apparatus. Here, the vehicular refrigeration apparatus of the present embodiment cools the internal temperature to, for example, an extremely low temperature around −20 ° C.

In the cycle 10 using the ejector of the present embodiment, the compressor 11 that sucks and compresses the refrigerant is rotationally driven by a vehicle travel engine (not shown) via an electromagnetic clutch 12 and a belt. The compressor 11 is intermittently connected to the vehicle running engine due to the energization of the electromagnetic clutch 12, and the operation is interrupted. That is, the refrigerant discharge capacity of the compressor 11 is adjusted by changing the operating rate of the compressor intermittent operation by the intermittent operation of the electromagnetic clutch 12.

A radiator 13 is disposed on the refrigerant discharge side of the compressor 11. The radiator 13 cools the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant discharged from the compressor 11 and outside air (air outside the vehicle compartment) blown by a cooling fan (not shown).

In this embodiment, since a normal chlorofluorocarbon refrigerant is used as the circulating refrigerant in the cycle, the cycle 10 using the ejector constitutes a subcritical cycle in which the high pressure does not exceed the critical pressure. Accordingly, the radiator 13 acts as a condenser that condenses the refrigerant.

  A liquid receiver 14 is arranged as a gas-liquid separator that separates the gas-liquid of the refrigerant and stores the liquid refrigerant in the downstream portion of the radiator 13, and the liquid refrigerant is led out from the receiver 14 to the downstream side. A throttle mechanism 15 is connected to the refrigerant downstream side of the liquid receiver 14.

  Specifically, the throttle mechanism 15 includes a fixed throttle such as a capillary tube or an orifice, and reduces the high-pressure liquid refrigerant from the liquid receiver 14 to a gas-liquid two-phase intermediate pressure refrigerant. An on-off valve 16 is connected to the downstream side of the throttle mechanism 15. The on-off valve 16 is specifically composed of an electromagnetic valve, and is controlled to open and close in conjunction with the intermittent operation of the compressor 11 as will be described later.

An ejector 17 is disposed further downstream than the on-off valve 16.
The ejector 17 is a decompression means for decompressing the refrigerant, and is also a refrigerant circulation means (momentum transporting pump) that circulates the refrigerant by a suction action (winding action) of the refrigerant flow ejected at high speed.

  In the ejector 17, the passage area of the intermediate pressure refrigerant flowing in through the on-off valve 16 is reduced to be the same as the nozzle part 17 a that decompresses and expands the intermediate pressure refrigerant isentropically, and the same refrigerant outlet as the nozzle part 17 a. A refrigerant suction port 17b that is disposed in the space and sucks a gas-phase refrigerant from the first evaporator 18 described later is provided.

  A mixing portion 17c that mixes the high-speed refrigerant flow from the nozzle portion 17a and the suction refrigerant from the refrigerant suction port 17b is provided on the downstream side of the nozzle portion 17a and the refrigerant suction port 17b. And the diffuser part 17d which makes | forms a pressure | voltage rise part is arrange | positioned downstream of the mixing part 17c.

  The diffuser portion 17d is formed in a shape that gradually increases the passage area of the refrigerant, and serves to increase the refrigerant pressure by decelerating the refrigerant flow, that is, to convert the velocity energy of the refrigerant into pressure energy.

  Further, the ejector 17 is provided with a passage opening / closing mechanism 17e that variably controls the passage area of the nozzle portion 17a. FIG. 2 shows a specific example of the passage opening / closing mechanism 17e, and a needle 17f is arranged in the passage of the nozzle portion 17a so as to be movable in the longitudinal direction of the passage. The tip of the needle 17f has an elongated and sharp shape.

  The root portion of the needle 17f is connected to the drive portion 17g, and the needle 17f moves in the longitudinal direction (vertical direction in FIG. 2) through the passage of the nozzle portion 17a by the operating force of the drive portion 17g. .

  The needle 17f moves downward from the position shown in FIG. 2, and the large diameter portion of the needle 17f comes into pressure contact with the inner wall surface of the minimum passage portion of the nozzle portion 17a, whereby the passage of the nozzle portion 17a can be fully closed. As the driving unit 17g, a motor actuator such as a stepping motor, an electromagnetic solenoid mechanism, or the like can be used, and various driving units can be used as long as they can be electrically controlled.

  The second evaporator 21 is connected to the downstream side of the diffuser portion 17 d of the ejector 17, and the refrigerant flow downstream side of the second evaporator 21 is connected to the suction side of the compressor 11.

  On the other hand, the refrigerant branch passage 19 is branched from the upstream portion of the ejector 17, and the downstream side of the refrigerant branch passage 19 is connected to the refrigerant suction port 17 b of the ejector 17. Z indicates a branch point of the refrigerant branch passage 19.

  A throttle mechanism 20 is disposed in the refrigerant branch passage 19, and a first evaporator 18 is disposed on the downstream side of the throttle mechanism 20. The throttle mechanism 20 is a pressure reducing means for adjusting the flow rate of the refrigerant to the first evaporator 18, and can be specifically constituted by a fixed throttle such as a capillary tube or an orifice. An electric control valve whose valve opening (passage opening) can be adjusted by an electric actuator may be used as the throttle mechanism 20.

  In this embodiment, the two evaporators 18 and 21 are assembled into an integral structure. Specifically, the constituent parts of the two evaporators 18 and 21 may be made of aluminum and joined into an integral structure by brazing.

  Then, air (cooled air) is blown as indicated by an arrow A by the common electric blower 22 for the two evaporators 18 and 21, and this blown air is cooled by the two evaporators 18 and 21. Yes. The cold air cooled by the two evaporators 18 and 21 is sent to the common cooling target space 23, and thereby the common cooling target space 23 is cooled by the two evaporators 18 and 21.

  Here, of the two evaporators 18 and 21, the second evaporator 21 connected to the flow path on the downstream side of the ejector 17 is arranged on the upstream side in the air flow direction A and connected to the refrigerant suction port 17 b of the ejector 17. The first evaporator 18 is arranged on the downstream side in the air flow direction A.

In this embodiment, since the cycle 10 using the ejector is applied to the vehicle refrigeration apparatus as described above, the cooling target space 23 is a space inside the freezer for storing the items to be frozen. A temperature sensor (thermistor) 24 for detecting the internal temperature is disposed in the cooling target space 23.

  Next, the outline of the electric control unit of the present embodiment will be described with reference to FIG. 3. The control device 25 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The control device 25 performs various calculations and processes based on the control program stored in the ROM, and controls the operations of the various devices 12, 16, 17g, 22 and the like described above.

  In addition to the detection value of the temperature sensor 24 described above being input to the control device 25, detection signals from the sensor group 26 and various operation signals from the operation panel 27 are input.

  Specifically, an outside air sensor or the like that detects an outside air temperature (a temperature outside the passenger compartment) is provided as the sensor group 26. The operation panel 27 is provided with a temperature setting switch for setting the cooling temperature of the cooling target space 23.

  Next, the operation of the first embodiment will be described. First, the basic operation in the operating state of the compressor 11 will be described. When the electromagnetic clutch 12 is energized by the control output of the control device 25 and the electromagnetic clutch 12 is in the connected state, the rotational power of the vehicle engine is transmitted to the compressor 11 and the compressor 11 is operated.

  In the operating state of the compressor 11, the on-off valve 16 is opened by the control output of the control device 25. In the ejector 17, the drive unit 17g is controlled by the control output of the control device 25, and the drive unit 17g. Moves the needle 17f to a predetermined opening position of the nozzle portion 17a.

  Therefore, the high-temperature and high-pressure refrigerant compressed and discharged by the compressor 11 flows into the radiator 13. In the radiator 13, the high-temperature refrigerant is cooled and condensed by the outside air. The refrigerant that has passed through the radiator 13 is separated into gas and liquid by the receiver 14, and the high-pressure liquid refrigerant is led to the downstream side of the receiver 14 and passes through the throttle mechanism 15.

  The high-pressure liquid refrigerant is decompressed to an intermediate pressure in a gas-liquid two-phase state by the throttle mechanism 15, and the intermediate-pressure refrigerant has a refrigerant flow toward the ejector 17 at the branch point Z and a refrigerant flow toward the branch refrigerant passage 19. Fork.

  The refrigerant flow that flows into the ejector 17 is decompressed and expanded by the nozzle portion 17a. Therefore, the pressure energy of the refrigerant is converted into velocity energy at the nozzle portion 17a, and the refrigerant is ejected at a high velocity from the outlet of the nozzle portion 17a. Due to the refrigerant pressure drop at this time, the refrigerant (gas-phase refrigerant) after passing through the first evaporator 18 in the branch refrigerant passage 19 is sucked from the refrigerant suction port 17b.

  The refrigerant ejected from the nozzle portion 17a and the refrigerant sucked into the refrigerant suction port 17b are mixed in the mixing portion 17c on the downstream side of the nozzle portion 17a and flow into the diffuser portion 17d. In the diffuser portion 17d, the passage area is enlarged, so that the speed (expansion) energy of the refrigerant is converted into pressure energy, so that the pressure of the refrigerant rises.

  Then, the refrigerant that has flowed out of the diffuser portion 17 d of the ejector 17 flows into the second evaporator 21. In the second evaporator 21, the low-temperature low-pressure refrigerant absorbs heat from the blown air in the direction of arrow A and evaporates. The vapor phase refrigerant after evaporation is sucked into the compressor 11 and compressed again.

  On the other hand, the refrigerant flow flowing into the branch refrigerant passage 19 is decompressed by the throttle mechanism 20 to become a low-pressure refrigerant, and this low-pressure refrigerant flows into the first evaporator 18. In the first evaporator 18, the refrigerant absorbs heat from the blown air in the direction of arrow A and evaporates. The vapor phase refrigerant after evaporation is sucked into the ejector 17 from the refrigerant suction port 17b.

  As described above, according to this embodiment, the refrigerant on the downstream side of the diffuser portion 17d of the ejector 17 is supplied to the second evaporator 21, and the refrigerant on the branch passage 19 side is also supplied to the first evaporator 18 through the throttle mechanism 20. Therefore, the first and second evaporators 18 and 21 can simultaneously exhibit a cooling action. Therefore, the cooling target space 23 can be cooled by blowing the cool air cooled by both the first and second evaporators 18 and 21 to the cooling target space 23.

  At that time, the refrigerant evaporating pressure of the second evaporator 21 is a pressure after being increased by the diffuser portion 17d, and the outlet side of the first evaporator 18 is connected to the refrigerant suction port 17b of the ejector 17. The lowest pressure immediately after the pressure reduction at the nozzle portion 17a can be applied to the first evaporator 18.

  Thereby, the refrigerant evaporation pressure (refrigerant evaporation temperature) of the first evaporator 18 can be made lower than the refrigerant evaporation pressure (refrigerant evaporation temperature) of the second evaporator 21. And since the 2nd evaporator 21 with a high refrigerant | coolant evaporation temperature is arrange | positioned in the upstream with respect to the flow direction A of blowing air, and the 1st evaporator 18 with a low refrigerant | coolant evaporation temperature is arrange | positioned in the downstream, 2nd Both the temperature difference between the refrigerant evaporation temperature and the blown air in the evaporator 21 and the temperature difference between the refrigerant evaporation temperature and the blown air in the second evaporator 18 can be ensured.

For this reason, both the cooling performance of the 1st, 2nd evaporators 18 and 21 can be exhibited effectively. Therefore, the cooling performance for the common cooling target space 23 can be effectively improved by the combination of the first and second evaporators 18 and 21. Further, the compressor 11 is driven by the pressure increasing action in the diffuser portion 17d.
As a result, the driving power of the compressor 11 can be reduced.

In the cycle 10 using the ejector of the present embodiment, the refrigerant branch passage 19 branched from the branch point Z upstream of the ejector 17 is connected to the refrigerant suction port 17b of the ejector 17, and the throttle mechanism is connected to the refrigerant branch passage 19. Since the first evaporator 18 and the first evaporator 18 are provided, low-pressure gas-liquid two-phase refrigerant can be independently supplied to the first evaporator 18 through the refrigerant branch passage 19.

  Therefore, the refrigerant flow rate on the first evaporator 18 side can be adjusted independently by the throttle mechanism 20 without depending on the function of the ejector 17.

  Further, under the condition where the cycle heat load is small, the high / low pressure difference of the cycle becomes small and the input of the ejector 17 becomes small. In this case, in the cycle of Patent Document 1, the flow rate of the refrigerant passing through the evaporator on the ejector suction side (corresponding to the first evaporator 18 of the present embodiment) depends only on the refrigerant suction capability of the ejector. Decrease → Decreasing the refrigerant suction capacity of the ejector → Decreasing the refrigerant flow rate of the suction side evaporator, making it difficult to secure the cooling performance of the suction side evaporator.

  On the other hand, according to the present embodiment, the refrigerant flow is branched at the upstream portion of the ejector 17, and the branched refrigerant is sucked into the refrigerant suction port 17 b through the refrigerant branch passage 19. Parallel connection relationship.

  For this reason, the refrigerant can be supplied to the refrigerant branch passage 19 by utilizing not only the refrigerant suction capability of the ejector 17 but also the refrigerant suction / discharge capability of the compressor 11. Thereby, even if the phenomenon that the input of the ejector 17 is reduced and the refrigerant suction capacity of the ejector 17 is reduced occurs, the degree of decrease in the refrigerant flow rate on the first evaporator 18 side can be made smaller than the cycle of Patent Document 1. Therefore, it is easy to ensure the cooling performance of the first evaporator 18 even under low heat load conditions.

  Next, intermittent control of the operation of the compressor 11 will be described. The operation of the compressor 11 is basically intermittently controlled based on the internal temperature (hereinafter, abbreviated as internal temperature) Tr of the cooling target space 23 detected by the temperature sensor 24.

  Specifically, as shown in FIG. 4, when the internal temperature Tr decreases to the lower limit set temperature Toff, the control device 25 cuts off the energization of the electromagnetic clutch 12 and stops the operation of the compressor 11. When the internal temperature Tr rises due to the operation stop of the compressor 11 and rises to the upper limit set temperature Ton, the control device 25 energizes the electromagnetic clutch 12 and restarts the compressor 11.

  Here, the lower limit set temperature Toff is, for example, a temperature of about −20 ° C. to −22 ° C., and the upper limit set temperature Ton is a temperature higher than the lower limit set temperature Toff by a predetermined temperature, for example, about −16 ° C. to −18 ° C. Temperature.

  In this way, by intermittently controlling the operation of the compressor 11 according to the level of the internal temperature Tr, the internal temperature Tr is controlled to a predetermined temperature range between the lower limit set temperature Toff and the upper limit set temperature Ton.

  For such intermittent control of the compressor 11, the opening / closing valve 16 and the passage opening / closing mechanism 17 e of the ejector 17 are interlocked and controlled by the control device 25 as follows. That is, when the internal temperature Tr decreases to the lower limit set temperature Toff, the on-off valve 16 and the passage opening / closing mechanism 17e of the ejector 17 are both moved to the closed state in conjunction with the stop of the operation of the compressor 11.

  And after maintaining the closed state of the on-off valve 16 for the 1st predetermined time t1 in the stop period of the compressor 11, the on-off valve 16 is first returned to an open state. After the second predetermined time t2 elapses after the opening / closing valve 16 is returned to the open state, the passage opening / closing mechanism 17e of the ejector 17 is returned to the open state.

  After the passage opening / closing mechanism 17e is returned to the open state, the compressor 11 is restarted. The first predetermined time t1 and the second predetermined time t2 are set so that t1> t2.

  Here, as a specific example of the opening / closing control of the passage opening / closing mechanism 17e of the opening / closing valve 16 and the ejector 17, either (1) control based on the internal temperature Tr or (2) control based on the timer function may be used.

  First, the former control (1) will be described. As shown in FIG. 4, a first auxiliary set temperature T1 that is higher than the lower limit set temperature Toff by a predetermined value as the set temperature for the internal temperature Tr, and this first auxiliary A second auxiliary set temperature T2 that is slightly higher than the set temperature T1 and slightly lower than the upper limit set temperature Ton is set.

  When the internal temperature Tr rises to the first auxiliary set temperature T1 after the compressor 11 is stopped, the on-off valve 16 is first returned to the open state. When the internal temperature Tr further rises and reaches the second auxiliary set temperature T2, the passage opening / closing mechanism 17e of the ejector 17 is also returned to the open state. Thereafter, when the internal temperature Tr further rises and reaches the upper limit set temperature Ton, the compressor 11 is restarted. FIG. 5A is a table summarizing the open / close state of the open / close valve 16 determined based on the internal temperature Tr.

  On the other hand, in the case of the latter control (2), the first predetermined time t1 and the second predetermined time t2 are directly set by the timer function of the control device 25. FIG. 5B is a specific example of a method for determining the first predetermined time t1, that is, the closing time t1 of the on-off valve 16, and details will be described later.

  As described above, when the on-off valve 16 is closed in conjunction with the stop of the compressor 11, the upstream flow path at the branch point Z is cut off. Thereby, when the compressor 11 is stopped, the refrigerant on the upstream side of the opening / closing valve 16 can be prevented from flowing into the flow path on the ejector 17 side and the branch passage 19 side due to the difference in cycle high and low pressure.

  Therefore, it is possible to prevent generation of refrigerant flow noise when passing through the nozzle portion 17a of the ejector 17 and the throttle mechanism 20 of the branch passage 19 when the compressor 11 is stopped.

  At the same time, liquid refrigerant can be prevented from accumulating in the first and second evaporators 18 and 21, so that liquid refrigerant can be returned to the compressor 11 and liquid compression can be prevented at the next compressor start-up.

  Further, during the first predetermined time t1 when the on-off valve 16 is in the closed state, it is possible to prevent the refrigerant on the upstream side of the on-off valve 16 from flowing into the first and second evaporators 18, 21, so that the cycle high and low pressure The pressure balance is suppressed.

  Specifically, as shown by the solid line in the lower part of FIG. 4, after the compressor is stopped, the high pressure is slightly decreased during the first predetermined time t <b> 1 during which the on-off valve 16 is maintained in the closed state than when the compressor is operating. In addition, the low pressure is only slightly increased compared to when the compressor is operating, and is maintained at a relatively low value.

  This means that the refrigerant temperature in the first and second evaporators 18 and 21 is maintained at a relatively low value even after the compressor is stopped.

  Here, if the refrigerant flows into the first and second evaporators 18 and 21 from the high-pressure side when the compressor is stopped, the low-pressure pressure increases → the refrigerant temperature in the first and second evaporators 18 and 21 increases. Eventually, the inside temperature rises. And the rise in the internal temperature leads to the problem of shortening the compressor stop period → increasing the compressor drive power, but according to the present embodiment, by closing the on-off valve 16 when the compressor is stopped, The trouble like this can be avoided.

  Since the cooling action of the first and second evaporators 18 and 21 is substantially stopped when the compressor is stopped, in this embodiment, the electric blower 22 that blows air to the first and second evaporators 18 and 21 is provided. It stops in conjunction with the compressor stop. However, when there is a high need to make the temperature distribution in the cooling target space 23 particularly uniform, the operation of the electric blower 22 may be continued even when the compressor is stopped.

  Further, when the on-off valve 16 closes in conjunction with the stop of the compressor, if the on-off valve 16 suddenly cuts off the flow of the incompressible liquid phase refrigerant, the refrigerant pressure upstream of the on-off valve suddenly rises and the water is increased. There is a concern that a hammering phenomenon may occur, thereby causing abnormal noise. However, in this embodiment, the throttle mechanism 15 is disposed upstream of the on-off valve 16, and the flow of the intermediate-pressure refrigerant in the gas-liquid two-phase state after being depressurized by the throttling mechanism 15 is shut off by the on-off valve 16. The on-off valve 16 blocks the refrigerant flow including the compressible gas phase refrigerant.

  As a result, it is possible to suppress a sudden rise in the refrigerant pressure upstream of the on-off valve 16 when the on-off valve 16 is closed, thereby avoiding the water hammering phenomenon and preventing the generation of abnormal noise due to the phenomenon.

  The on-off valve 16 is kept closed for the first predetermined time t1, and then returned to the open state. At this time, since the passage opening / closing mechanism 17e of the ejector 17 is still in the closed state, the refrigerant that has passed through the opening / closing valve 16 passes only through the branch passage 19 and passes through the first evaporator 18 → the ejector 17 → the second evaporation. It flows in the order of the vessel 21.

  As a result, a so-called pressure balance is made to equalize the high pressure and low pressure of the cycle. Specifically, when the on-off valve 16 is opened, the high-pressure side refrigerant flows into the low-pressure side flow path, so that the high-pressure pressure is further increased from the value when the on-off valve 16 is closed as shown in the lower part of FIG. Decreases to a lower value. Along with this, the low pressure increases from the value when the on-off valve 16 is closed to a higher value.

  This pressure balance is performed from the opening of the on-off valve 16 until the compressor 11 is restarted (time t3). This time t3 is a pressure balance period. The broken lines b and c of the high pressure and the low pressure in the lower part of FIG. 4 indicate the pressure balance when the on-off valve 16 is not controlled to open and close as indicated by the broken line d, and the high pressure and the low pressure are the same in the middle. The case where the pressure value is completely balanced is shown.

  On the other hand, in the present embodiment, during the stop period of the compressor 11, the pressure balance is performed only during the latter half of the period t3, so the pressure balance is finished before the high pressure and the low pressure become the same intermediate pressure value. To do. As a result, there is a predetermined pressure difference between the high pressure and the low pressure even at the end of the pressure balance (when the compressor 11 is restarted).

  However, since the high / low pressure difference can be reduced by performing the pressure balance, the starting power of the compressor 11 can be greatly reduced as compared with the case where the compressor 11 is restarted while maintaining the large high / low pressure difference.

  Further, during most of the pressure balance period t3, the passage opening / closing mechanism 17e of the ejector 17 is maintained in the closed state, so that it is possible to prevent generation of refrigerant flow noise in the nozzle portion 17a of the ejector 17.

  In FIG. 4, the return of the passage opening / closing mechanism 17 e of the ejector 17 to the open state is slightly preceded by the time when the compressor 11 is restarted, but this is before the restart of the compressor 11. In order to ensure that the passage opening / closing mechanism 17e is in an open state and the passage opening / closing mechanism 17e can be brought into the open state in a very short time, the passage opening / closing mechanism 17e is opened simultaneously with the restart of the compressor 11. You may make it return to a state.

  In FIG. 4, both the on-off valve 16 and the passage opening / closing mechanism 17 e are simultaneously closed simultaneously with the stop of the compressor 11, but the refrigerant inflow to the ejector 17 can be prevented by the closed state of the on-off valve 16. The passage opening / closing mechanism 17e may be closed after a predetermined time from the closing time of the opening / closing valve 16, as indicated by a broken line a in FIG.

  By the way, a preferable specific example in which the valve closing time (first predetermined time t1) of the on-off valve 16 is set by the timer function of the control device 25 as in the above-described control (2) will be described. When the cycle heat load is small There is a correlation that the degree of increase in the internal temperature during the compressor stop period becomes smaller and the compressor stop period becomes longer.

  Therefore, as shown in FIG. 5B, the valve closing time t1 of the on-off valve 16 may be determined according to the outside air temperature. Specifically, when the outside air temperature is in a low temperature range below the first predetermined temperature Ta, the valve closing time t1 = A minutes is determined, and the outside air temperature exceeds the first predetermined temperature Ta and is below the second predetermined temperature Tb. When the temperature is in the intermediate temperature range, the valve closing time t1 is determined as B minutes, and when the outside air temperature is in the high temperature range exceeding the second predetermined temperature Tb, the valve closing time t1 is determined as C minutes.

  Here, there is a relationship of A minute> B minute> C minute, and the valve closing time t <b> 1 of the on-off valve 16 is determined to be sequentially increased according to the decrease in the outside air temperature (that is, the decrease in the cycle heat load). Thereby, the valve closing time t1 of the on-off valve 16 can be determined at an appropriate time corresponding to the heat load condition.

  In addition, although FIG. 4 demonstrated the case where the operation | movement of the compressor 11 was interrupted based on the change of the internal temperature Tr, a passenger | crew manually operates the cycle operation switch with which the operation panel 27 was equipped, and compression is carried out. Even when the operation of the machine 11 is interrupted, the operation of various devices may be controlled as shown in FIG.

(Second Embodiment)
In the first embodiment, the on-off valve 16 is closed in conjunction with the stop of the compressor 11, but in the second embodiment, when the internal temperature Tr decreases to the lower limit set temperature Toff as shown in FIG. Prior to the stop of the compressor 11, the on-off valve 16 is first closed. Accordingly, the operation of the compressor 11 is continued for a predetermined time t4 while the upstream passage at the branch point Z is blocked, and the compressor 11 is stopped after the predetermined time t4 has elapsed.

  Here, the predetermined time t4 is a period of pump-down operation in which the compressor 11 sucks the refrigerant on the cycle low pressure side, moves it to the high pressure side, and holds it on the high pressure side. By performing this pump-down operation, the amount of refrigerant accumulated in the first and second evaporators 18 and 21 during the compressor stop period can be further reduced as compared with the first embodiment. Therefore, the risk of liquid refrigerant return and liquid compression at the next restart of the compressor can be more effectively prevented.

  The pump down time t4 is preferably determined according to the outside air temperature as shown in FIG. That is, when the outside air temperature is in the low temperature range below the first predetermined temperature Ta, the pump down time t4 = G minutes is determined, and the outside temperature exceeds the first predetermined temperature Ta and is the intermediate temperature range below the second predetermined temperature Tb. Is determined as the pump down time t4 = H minutes, and when the outside air temperature is in the high temperature range exceeding the second predetermined temperature Tb, the pump down time t4 = I minutes is determined.

  Here, G> H> I, and the pump down time t4 is determined to be sequentially increased in accordance with a decrease in the outside air temperature (that is, a decrease in the cycle heat load). Thereby, the pump down time t4 can be determined at an appropriate time corresponding to the heat load condition.

(Third embodiment)
In the first embodiment, the throttle mechanism 15 and the opening / closing valve 16 are disposed further upstream than the branch point Z upstream of the ejector 17. In the third embodiment, as shown in FIG. The upstream throttle mechanism 15 and the open / close valve 16 are eliminated, and instead, the open / close valve 16 is arranged between the downstream side of the throttle mechanism 20 of the branch passage 19 and the upstream side of the first evaporator 18.

  Therefore, according to the third embodiment, the on-off valve 16 only performs passage blocking on the branch passage 19 side. Therefore, in the third embodiment, in conjunction with the stop of the compressor 11, both the on-off valve 16 and the passage opening / closing mechanism 17e of the ejector 17 are simultaneously shifted to the closed state. Thereby, when the compressor is stopped, the flow path on the ejector 17 side can be shut off by the passage opening / closing mechanism 17e.

  FIG. 9 shows the operation of various devices linked to the intermittent operation of the compressor according to the third embodiment. Except that the passage opening / closing mechanism 17e of the ejector 17 is always closed simultaneously with the stop of the compressor 11, FIG. It may be the same as FIG. In FIG. 9, t5 indicates the closing time of the passage opening / closing mechanism 17e of the ejector 17 when the compressor is stopped.

  FIG. 10A shows a control example in the case where the opening / closing of the opening / closing valve 16 and the passage opening / closing mechanism 17e of the ejector 17 is determined based on the internal temperature Tr when the compressor is stopped in the third embodiment. Since it is the same idea as (a), a specific description is omitted.

  FIG. 10B is a control example in the case where the closing time t1 of the on-off valve 16 and the closing time t5 of the passage opening / closing mechanism 17e of the ejector 17 are determined by the timer function in the third embodiment when the compressor is stopped. This is the same concept as in FIG. That is, the closing time t1 of the on-off valve 16 when the compressor is stopped is determined to become longer as the outside air temperature becomes lower. In the figure, A> B> C. Further, the closing time t5 of the passage opening / closing mechanism 17e of the ejector 17 when the compressor is stopped is also determined to become longer as the outside air temperature becomes lower. In the figure, D> E> F.

(Fourth embodiment)
In the fourth embodiment, the same pump down control as that in FIG. 6 (second embodiment) is combined with the third embodiment (cycle configuration in FIG. 8).

  FIG. 11 shows the operation of various devices linked to the intermittent operation of the compressor according to the fourth embodiment. When the internal temperature Tr decreases to the lower limit set temperature Toff, the on-off valve 16 precedes the stop of the compressor 11. And the passage opening / closing mechanism 17e of the ejector 17 are simultaneously shifted to the closed state.

  Thereby, while being able to interrupt | block the upstream part of the 1st evaporator 18 of the branch passage 19, the inlet part of the ejector 17 can be interrupted | blocked. Then, the compressor 11 is continuously operated for a predetermined time t4 while maintaining the passage blocking state, and the compressor 11 is stopped after the predetermined time t4.

  Therefore, the compressor 11 performs a pump-down operation in which the refrigerant on the cycle low pressure side is sucked and moved to the high pressure side for a predetermined time t4. Thereby, the refrigerant | coolant amount which accumulates in the 1st, 2nd evaporators 18 and 21 during a compressor stop period can be reduced much more effectively.

  Also in the fourth embodiment, the pump-down operation time t4 is determined so as to increase sequentially in accordance with the decrease in the outside air temperature (that is, the decrease in the cycle heat load) as shown in FIG. preferable.

(Fifth embodiment)
FIG. 12 shows a fifth embodiment, which corresponds to a partly modified cycle configuration of the first embodiment. That is, in the fifth embodiment, the flow path switching mechanism 30 is installed in the branch passage 19 downstream of the first evaporator 18.

  Specifically, the flow path switching mechanism 30 is constituted by a three-way solenoid valve, and the downstream portion of the first evaporator 18 is directly connected to the downstream side of the second evaporator 21 (the suction side of the compressor 11). And a second state in which the downstream portion of the first evaporator 18 is connected to the refrigerant suction port 17b side.

  In the first embodiment, the first and second evaporators 18 and 21 are integrally configured, and air is blown by the blower 22 common to the first and second evaporators 18 and 21, and the first and second evaporations are performed. The common cooling target space 23 is cooled by the vessels 18 and 21, but this point is also changed in the fifth embodiment.

  That is, in the fifth embodiment, the first and second evaporators 18 and 21 are configured separately, and the first and second evaporators 18 and 21 are arranged in separate cooling target spaces 23a and 23b, respectively. ing. Therefore, air is blown to the first and second evaporators 18 and 21 by separate blowers 22a and 22b, respectively, and the separate cooling target spaces 23a and 23b are cooled.

  Here, since the refrigerant | coolant evaporation temperature of the 1st evaporator 18 is lower than the 2nd evaporator 21, the 1st evaporator 18 is rather than the internal temperature of the 2nd cooling object space 23b cooled by the 2nd evaporator 21. FIG. The inside temperature of the first cooling target space 23a that is cooled by the cooling becomes lower. For this reason, the 2nd cooling object space 23b is used as a refrigerating room, for example, and the 1st cooling object space 23a is used as a freezing room, for example.

  The two cooling target spaces 23a and 23b are provided with temperature sensors 24a and 24b for detecting the internal temperatures Tr1 and Tr2, respectively. The detection signals of the two temperature sensors 24a and 24b are input to the control device 25 (FIG. 2), and the switching operation of the flow path switching mechanism 30 and other devices (compressor 11, ejector) by the control output of the control device 25. The operation of the passage opening / closing mechanism 17e, the opening / closing valve 16 and the like) is controlled.

  FIG. 13 is an operation explanatory diagram of the fifth embodiment, and the internal temperature Tr1 of the first cooling target space 23a detected by the first temperature sensor 24a and the second cooling target space 23b detected by the second temperature sensor 24b. Lower limit set temperatures Toff1 and Toff2 and upper limit set temperatures Ton1 and Ton2 are set for the internal temperature Tr2.

  When the second internal temperature Tr2 decreases to the lower limit set temperature Toff2 at time t10, the control device 25 switches the flow path switching mechanism 30 from the second state to the first state. Accordingly, the downstream portion of the first evaporator 18 is directly connected to the downstream side of the second evaporator 21 (the suction side of the compressor 11). At the same time, the control device 25 closes the passage opening / closing mechanism 17e of the ejector 17, so that the refrigerant flow passing through the ejector 17 is blocked and refrigerant flow into the second evaporator 21 is prevented.

  Thereby, the cooling action of the second evaporator 21 is stopped, and the internal temperature Tr2 of the second cooling target space 23b starts to rise. On the other hand, the refrigerant continues to flow through the first evaporator 18, and the internal temperature Tr1 of the first cooling target space 23a further decreases after time t10.

  When the internal temperature Tr1 of the first cooling target space 23a decreases to the lower limit set temperature Toff1 at time t11, the control device 25 stops the compressor 11 and simultaneously closes the on-off valve 16. . The closed state of the on-off valve 16 is continued for a time t1, and the refrigerant flow into the first evaporator 18 and the second evaporator 21 is blocked. Accordingly, the internal temperature Tr1 of the first cooling target space 23a starts to increase from time t11.

  The on-off valve 16 returns to the valve open state after the time t1 has elapsed. At this time, since the compressor 11 continues to be stopped, the high and low pressures of the cycle change in the pressure equalization direction by opening the on-off valve 16, and the pressure balance of the cycle is performed. This pressure balance is performed for a time t3 until the compressor 11 is restarted. On the other hand, the passage opening / closing mechanism 17e of the ejector 17 returns to the open state after the elapse of time t2 after the open / close valve 16 returns to the open state (time t2 <time t3).

  Then, at time t12, when the internal temperature Tr2 of the second cooling target space 23b rises to the upper limit set temperature Ton2, the control device 25 restarts the compressor 11 and moves the flow path switching mechanism 30 from the first state. Switch to the second state. Accordingly, the downstream portion of the first evaporator 18 is connected to the refrigerant suction port 17 b side of the ejector 17.

  Thereafter, the operation as described above is repeated, and the internal temperature Tr1 of the first cooling target space 23a and the internal temperature Tr2 of the second cooling target space 23b are set to the lower limit set temperatures Toff1, Toff2 and the upper limit set temperatures Ton1, Ton2, respectively. Can be controlled within a predetermined temperature range. At the same time, the effects such as prevention of accumulation of liquid refrigerant in the first and second evaporators 18 and 21 when the compressor 11 is stopped can be exhibited as in the first embodiment.

  In the above description of the operation, it has been described that the compressor 11 is stopped when the internal temperature Tr1 of the first cooling target space 23a is lowered to the lower limit set temperature Toff1, but more specifically, the first cooling target space (one side) Of the second cooling target space (the other cooling target space) 23b does not rise to the upper limit set temperature Ton2. When the AND condition is satisfied, the compressor 11 is stopped. This is because when the AND condition is satisfied, it is possible to determine a state in which the cooling operation of both the first and second evaporators 18 and 21 may be interrupted.

  In short, when the internal temperature of one of the two cooling target spaces 23a and 23b is lowered to the lower limit set temperature, the compressor 11 is in the case where the internal temperature of the other space is not increased to the upper limit set temperature. Can be stopped.

  FIG. 13 illustrates an example in which the internal temperature Tr2 of the second cooling target space 23b rises to the upper limit set temperature Ton2, and the compressor 11 is restarted. However, the storage in the second cooling target space 23b is illustrated. If the internal temperature Tr1 of the first cooling target space 23a rises to the upper limit set temperature Ton1 earlier than the internal temperature Tr2, the compressor 11 may be restarted at that time.

  In short, the compressor 11 is kept stopped while neither the internal temperature Tr1 of the first cooling target space 23a nor the internal temperature Tr2 of the second cooling target space 23b has risen to the upper limit set temperatures Ton1 and Ton2. When either one of the internal temperature Tr1 of the first cooling target space 23a and the internal temperature Tr2 of the second cooling target space 23b rises to the upper limit set temperatures Ton1 and Ton2, the compressor 11 is restarted. Just start.

  In addition, what is necessary is just to control the action | operation of the air blowers 22a and 22b of the 1st, 2nd cooling object space 23a, 23b in response to the refrigerant | coolant flow intermittent to each corresponding evaporator 18,21. That is, the blower 22a in the first cooling target space 23a may be stopped in conjunction with the refrigerant flow interruption to the first evaporator 18, and the blower 22a may be restarted in conjunction with the restart of the compressor 11. Similarly, the blower 22b in the second cooling target space 23b may be stopped in conjunction with the refrigerant flow interruption to the second evaporator 21, and the blower 22b may be restarted in conjunction with the restart of the compressor 11.

(Sixth embodiment)
FIG. 14 shows a sixth embodiment, which is a modification of the fifth embodiment. In the sixth embodiment, a bypass passage 31 of the second evaporator 21 is provided, and a flow path switching mechanism 30 is disposed at a branch point between the bypass passage 31 and the second evaporator 21.

  The flow path switching mechanism 30 is also specifically constituted by a three-way solenoid valve, and a first state in which the downstream portion of the ejector 17 is connected to the bypass passage 31 and a second state in which the downstream portion of the ejector 17 is connected to the second evaporator 21. Switch between 2 states.

  The operation of the sixth embodiment may be basically performed in the same manner as in FIG. However, in the sixth embodiment, when the flow path switching mechanism 30 is switched from the second state to the first state at time t10 in FIG. 13, the refrigerant inflow to the second evaporator 21 is blocked. There is no need to close the passage opening / closing mechanism 17e of the ejector 17, and the opening state of the passage opening / closing mechanism 17e is continued.

  Then, when the compressor 11 is stopped and the on-off valve 16 is closed at time t11 in FIG. 13, the passage opening / closing mechanism 17e of the ejector 17 may be closed. Except for the opening / closing operation of the ejector 17 of the sixth embodiment, the other operations may be the same as those of the fifth embodiment.

(Seventh embodiment)
FIG. 15 shows a seventh embodiment. In the seventh embodiment, a second branch passage 32 is provided separately from the first branch passage 19 corresponding to the branch passage 19 of the first to sixth embodiments.

  The second branch passage 32 is provided between the downstream portion of the on-off valve 16 and the suction side of the compressor 11, and a flow path switching mechanism 30 is provided at a branch position of the second branch passage 32. This flow path switching mechanism 30 is also specifically constituted by a three-way solenoid valve, and a first state in which the downstream portion of the on-off valve 16 is connected to the branch point Z side upstream of the ejector 17 and a downstream portion of the on-off valve 16 are connected. The second state connected to the second branch passage 32 side is switched.

  A throttle mechanism 33 is provided upstream of the second branch passage 32, and a third evaporator 34 is provided downstream of the throttle mechanism 33.

  In the seventh embodiment, the first and second evaporators 18 and 21 are integrally configured and arranged in the first cooling target space 23a together with the blower 22a and the temperature sensor 24a. Moreover, the 3rd evaporator 34, the air blower 22b, and the temperature sensor 24b are arrange | positioned in the 2nd cooling object space 23b.

  FIG. 16 is an operation explanatory diagram of the seventh embodiment. When the internal temperature Tr2 of the second cooling target space 23b decreases to the lower limit set temperature Toff2, the flow path switching mechanism 30 moves the downstream portion of the on-off valve 16 upstream of the ejector 17. It switches to the 1st state connected to the branch point Z side of a part. When the internal temperature Tr2 rises to the upper limit set temperature Ton2, the flow path switching mechanism 30 is switched to the second state in which the downstream portion of the on-off valve 16 is connected to the second branch passage 32 side.

  In contrast, the intermittent operation of the compressor 11 is determined based on the internal temperatures Tr1 and Tr2 of both the first and second cooling target spaces 23a and 23b. Specifically, as shown in time t13 of FIG. 16, when the internal temperature Tr1 of the first cooling target space 23a is lowered to the lower limit set temperature Toff1, the internal temperature Tr2 of the second cooling target space 23b is set to the upper limit. If the temperature has not risen to Ton2, the compressor 11 is stopped.

  In conjunction with the stop of the compressor 11, the passage opening / closing mechanism 17e and the opening / closing valve 16 of the ejector 17 are closed. The closing time t1 of the on-off valve 16 after the stop of the compressor 11, the pressure balance time t3, the closing time t2 of the ejector 17 at the pressure balance time t3, and the like may be determined in the same way as in the first to sixth embodiments. .

(Eighth embodiment)
FIG. 17 shows an eighth embodiment, and a third evaporator 34 and a bypass passage 35 of the third evaporator 34 are provided in parallel on the downstream side of the second evaporator 21. A flow path switching mechanism 30 is provided at a branch position of the parallel circuit.

  This flow path switching mechanism 30 is also specifically configured by a three-way solenoid valve, and a first state in which the downstream portion of the second evaporator 21 is connected to the bypass passage 35 side, and a downstream portion of the second evaporator 21 is a third state. The second state connected to the evaporator 34 side is switched.

  Also in the eighth embodiment, the first and second evaporators 18 and 21 are integrally configured and disposed in the first cooling target space 23a together with the blower 22a and the temperature sensor 24a. Moreover, the 3rd evaporator 34, the air blower 22b, and the temperature sensor 24b are arrange | positioned in the 2nd cooling object space 23b.

  FIG. 18 is an operation explanatory view of the eighth embodiment, and the flow switching of the flow switching mechanism 30, the intermittent operation of the compressor 11, the on-off valve 16, The ejector 17 is opened and closed.

(Ninth embodiment)
FIG. 19 shows a ninth embodiment, in which a third evaporator 34 is provided in parallel with the second evaporator 21. And the 1st evaporator 18, the 2nd evaporator 21, and the 3rd evaporator 34 are arrange | positioned in the cooling object space 23a, 23b, 23c, respectively. Blowers 22a, 22b, 22c and temperature sensors 24a, 24b, 24c are individually arranged in the respective cooling target spaces 23a, 23b, 23c.

  Also in the ninth embodiment, the lower limit set temperatures Toff1, Toff2, Toff3 and the upper limit set temperatures Ton1, Ton2, Ton3 are set corresponding to the internal temperatures Tr1, Tr2, Tr3 detected by the temperature sensors 24a, 24b, 24c, respectively. To do.

  The intermittent operation of the compressor 11 in the ninth embodiment may be performed as follows based on the internal temperatures Tr1, Tr2, and Tr3 detected by the temperature sensors 24a, 24b, and 24c. That is, when any one of the inside temperatures Tr1, Tr2, Tr3 of the first to third cooling target spaces 23a, 23b, 23c is lowered to the lower limit set temperature, the other two insides When none of the temperatures has risen to the upper limit set temperature, the compressor 11 is stopped.

  Then, after the compressor 11 is stopped, the compressor 11 is in a stopped state while the internal temperature Tr1, Tr2, Tr3 of the first to third cooling target spaces 23a, 23b, 23c has not risen to the upper limit set temperature. The compressor 1 may be restarted when any one of the internal temperatures Tr1, Tr2, Tr3 rises to the upper limit set temperature. The opening / closing of the on-off valve 16 and the ejector 17 may be performed in the same way as in the other embodiments.

(10th Embodiment)
In the ninth embodiment, the third evaporator 34 is provided in parallel with the second evaporator 21, but in the tenth embodiment, as shown in FIG. 20, the series circuit of the ejector 17 and the second evaporator 21 A second branch passage 32 is provided in parallel, a throttle mechanism 33 is provided on the upstream side of the second branch passage 32, and a third evaporator 34 is provided on the downstream side of the throttle mechanism 33.

  And the 1st evaporator 18, the 2nd evaporator 21, and the 3rd evaporator 34 are arrange | positioned in the cooling object space 23a, 23b, 23c, respectively. This is the same as in the ninth embodiment. Therefore, the intermittent operation of the compressor 11 may be performed in the same manner as in the ninth embodiment.

  In all of the cycle configurations (FIGS. 12, 14, 15, 17, 19, and 20) of the fifth to tenth embodiments, the throttle mechanism of the first embodiment is disposed upstream of the on-off valve 16. In the fifth to tenth embodiments, the water hammer ring phenomenon is suppressed by providing the throttle mechanism 15 at the upstream portion of the on-off valve 16 in the fifth to tenth embodiments as well. Of course, it can be effective.

(Eleventh embodiment)
In the first embodiment, the on-off valve 16 is provided upstream of the branch point Z. In the eleventh embodiment, a three-way valve type on-off valve 16 is provided at the position of the branch point Z as shown in FIG. .

  The three-way valve type on-off valve 16 is also specifically constituted by an electromagnetic valve. The on-off valve 16 has an open state in which the downstream portion (high pressure passage portion) of the liquid receiver 14 is simultaneously connected to the upstream passage and the branch passage 19 of the ejector 17, and the downstream portion (high pressure passage portion) of the liquid receiver 14. The valve closing state for switching between the upstream side passage and the branch passage 19 of the ejector 17 is switched.

  According to this, by switching the on-off valve 16 to the above-mentioned closed state in conjunction with the stop of the compressor 11, it is possible to exert effects such as prevention of refrigerant flow noise and prevention of liquid refrigerant return at the time of starting the compressor. .

  In the eleventh embodiment, the throttle mechanism 15 may be disposed upstream of the on-off valve 16 so that the water hammering phenomenon when the on-off valve 16 is closed can be suppressed.

(Twelfth embodiment)
In the third embodiment shown in FIG. 8, the on-off valve 16 is disposed downstream of the throttle mechanism 20 in the branch passage 19, but in the twelfth embodiment, the first in the branch passage 19 is shown in FIG. The second throttle mechanisms 20a and 20b are provided in series, and the on-off valve 16 is disposed between the first and second throttle mechanisms 20a and 20b. Even if it does in this way, the effect similar to 3rd Embodiment can be exhibited.

(13th Embodiment)
FIG. 23 shows a thirteenth embodiment, in which the on-off valve 16 is arranged upstream of the throttle mechanism 20 in the branch passage 19.

  According to the thirteenth embodiment, since the on-off valve 16 is located on the upstream side of the throttle mechanism 15, it is not possible to expect the effect of suppressing the water hammering phenomenon when the on-off valve 16 is closed. By closing the on-off valve 16 when the compressor is stopped, effects such as prevention of refrigerant flow noise and prevention of liquid refrigerant return at the start of the compressor can be exhibited.

(14th Embodiment)
FIG. 24 is a fourteenth embodiment and relates to an assembly structure having a cycle configuration. The fourteenth embodiment has the same cycle configuration as the first embodiment.

  The throttle mechanism 15, the on-off valve 16, the ejector 17, and the throttle mechanism 20 of the branch passage 19 are assembled as one integrated unit 40. Here, the integrated unit 40 is a collective assembly in which the plurality of parts 15, 16, 17, and 20 are assembled in advance as an integrated structure. Therefore, the entire integrated unit 40 can be handled as one component.

  The first and second evaporators 18 and 21 are also integrally structured by brazing or the like as described above, and constitute an integrated unit 41.

  Therefore, by integrating the integrated unit 40 such as the ejector 17 with the integrated unit 41 of the first and second evaporators 18 and 21, the integrated units 40 and 41 can be further integrated.

  Such integration makes it possible to reduce the overall size of the integrated units 40 and 41 and reduce the mounting space on the vehicle or the like. Furthermore, since both the integrated units 40 and 41 can be mounted at once as one device, the mounting work on a vehicle or the like can be made efficient.

  Moreover, since only one refrigerant inlet part 42 and one refrigerant outlet part 43 need only be set for the integrated units 40 and 41 as a whole, the refrigerant pipe connection with the outside of the unit can be easily performed.

(Fifteenth embodiment)
In the first to fourteenth embodiments, the cycle configuration in which the liquid receiver 14 is disposed on the downstream side of the radiator 13 has been described. However, in the fifteenth embodiment, the liquid receiver 14 is eliminated as shown in FIG. Instead, an accumulator 44 that is a gas-liquid separator that separates the gas-liquid refrigerant and derives the gas-phase refrigerant is arranged on the suction side of the compressor 11. The present invention may be implemented in such a cycle configuration with the accumulator 44.

When a refrigerant whose high pressure exceeds the critical pressure, such as carbon dioxide (CO2), is used as the refrigerant, the cycle 10 using the ejector becomes a supercritical cycle, so that the high-pressure refrigerant only dissipates heat in the supercritical state. And it doesn't condense. Accordingly, in such a supercritical cycle, there is no point in disposing the liquid receiver 14 on the downstream side of the radiator 13, and therefore it is preferable to adopt a cycle configuration with an accumulator 44 as in the fifteenth embodiment.

(Sixteenth embodiment)
In each of the first to fifteenth embodiments, the cycle configuration including the plurality of evaporators 18, 21, and 34 has been described. However, the sixteenth embodiment includes a cycle including only one evaporator 18 as shown in FIG. Concerning configuration.

  An accumulator 44 that is a gas-liquid separator is disposed on the downstream side of the ejector 17. A branch passage 45 that connects the liquid-phase refrigerant outlet of the accumulator 44 to the refrigerant suction port 17 b of the ejector 17 is provided, and the evaporator 18 is disposed in the branch passage 45.

  Since this evaporator 18 is located upstream of the refrigerant suction port 17b, it corresponds to the first evaporator 18 of the first to fifteenth embodiments. On the other hand, an on-off valve 16 is arranged upstream of the ejector 17.

  Also in the sixteenth embodiment, by closing the on-off valve 16 when the compressor 11 is stopped, the same effects as those in the first embodiment can be exhibited. In the sixteenth embodiment, the ejector 17 is not provided with the passage opening / closing mechanism 17e, but the passage opening / closing mechanism 17e may be provided as necessary.

(17th Embodiment)
The seventeenth embodiment is a modification of the sixteenth embodiment, and as shown in FIG. 27, the opening / closing valve 16 is eliminated, and instead, the passage 17 is provided with a passage opening / closing mechanism 17e. By bringing the mechanism 17e to the closed state, the same operational effects as those of the first embodiment and the like can be exhibited.

  In the sixteenth and seventeenth embodiments, the example in which the throttling mechanism 15 of the first embodiment is eliminated is shown, but in the sixteenth and seventeenth embodiments, the upstream portion of the on-off valve 16 or the passage opening / closing mechanism. Of course, the throttle mechanism 15 may be provided upstream of 17e.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and various modifications can be made as described below.

  (1) In each of the above-described embodiments, the temperature (internal temperature) of the cooling target spaces 23, 23a, 23b, 23c of the evaporators 18, 21, 34 is detected by the temperature sensors 24, 24a, 24b, 24c. However, instead of the internal temperature, a temperature correlated with the internal temperature, such as the evaporator surface temperature, may be detected.

  (2) In each of the above-described embodiments, the refrigeration cycle for the vehicle has been described. However, the present invention is not limited to the vehicle and can be similarly applied to a refrigeration cycle for stationary use.

(3) In each of the above-described embodiments, the type of the refrigerant was not specified, but the refrigerant is a refrigerant-type subcritical cycle or supercritical cycle such as CFC-based, HC-based alternative CFC, carbon dioxide (CO ₂ ), or the like. It may be applicable to any of them.

It is a cycle lineblock diagram showing the cycle using the ejector for vehicles by a 1st embodiment of the present invention. It is a partial schematic sectional drawing which shows the specific example of the channel | path opening / closing mechanism of the ejector by 1st Embodiment. It is a block diagram of the electric control part of 1st Embodiment. It is operation | movement explanatory drawing of 1st Embodiment. It is a chart which shows the way of thinking of on-off control of on-off valve at the time of compressor stop by a 1st embodiment. It is operation | movement explanatory drawing of 2nd Embodiment. It is a graph which shows how to determine the pump down time by 2nd Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 3rd Embodiment. It is operation | movement explanatory drawing of 3rd Embodiment. It is a table | surface which shows the view of the opening / closing control of the on-off valve at the time of the compressor stop by 3rd Embodiment. It is operation | movement explanatory drawing of 4th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 5th Embodiment. It is operation | movement explanatory drawing of 5th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 6th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 7th Embodiment. It is action | operation explanatory drawing of 7th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 8th Embodiment. It is action | operation explanatory drawing of 8th Embodiment. It is a cycle lineblock diagram showing the cycle using the ejector for vehicles by a 9th embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 10th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 11th Embodiment. It is a cycle lineblock diagram showing the cycle using the ejector for vehicles by a 12th embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 13th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 14th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 15th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 16th Embodiment. It is a cycle block diagram which shows the cycle using the ejector for vehicles by 17th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Compressor, 13 ... Radiator, 15, 20, 33 ... Throttling mechanism, 16 ... On-off valve (opening / closing means), 17 ... Ejector, 17a ... Nozzle part, 17b ... Refrigerant suction port, 17c ... Mixing part,
17d ... Diffuser section, 17e ... Path opening / closing mechanism (opening / closing means), 18 ... First evaporator,
19 ... Branch passage, 21 ... Second evaporator.

Claims (9)

A compressor (11) for sucking and compressing refrigerant;
A radiator (13) that radiates heat of the high-pressure refrigerant discharged from the compressor (11);
The radiator (13) has a refrigerant suction port (17b) for decompressing and expanding the refrigerant on the downstream side, and sucking the refrigerant into the interior by the high-speed refrigerant flow at the time of expansion, and from the refrigerant suction port (17b) An ejector (17) for mixing the suction refrigerant and the high-speed refrigerant flow, decelerating the mixed refrigerant flow and increasing the pressure of the refrigerant flow;
An evaporator (18) provided in a branch passage (19, 45) connected to the refrigerant suction port (17b);
On-off valve (16) provided on the upstream side of the evaporator (18) on the side of the refrigerant suction port (17b) and the ejector (17) as an opening / closing means capable of preventing the refrigerant from flowing into the evaporator (18) A passage opening and closing mechanism (17e) provided in itself;
Control means (25) for intermittently controlling the operation of the compressor (11),
The control means (25) closes the opening / closing means (16, 17e) within a period during which the operation of the compressor (11) is stopped, and the refrigerant upstream of the opening / closing means (16, 17e) is transferred to the ejector. (17) is prevented from flowing into the flow path, and the on-off valve (16) is first returned from the closed state to the open state during the stop period of the compressor (11), and the pressure balance in the cycle is A cycle using an ejector, which is executed, and then restarts the compressor (11) after the passage opening / closing mechanism (17e) is returned to the open state with a delay. The evaporator on the refrigerant suction port (17b) side is provided as a first evaporator (18), and a second evaporator (21) is provided on the downstream side of the ejector (17). A cycle using the ejector according to 1. The cycle using the ejector according to claim 2, wherein one common cooling target space (23) is cooled by the first evaporator (18) and the second evaporator (21). The cycle using the ejector according to claim 2, wherein separate cooling target spaces (23a, 23b) are cooled by the first evaporator (18) and the second evaporator (21). Temperature detecting means (24, 24a, 24b) for detecting a temperature correlated with the temperature of the cooling target space (23, 23a) of the evaporator (18),
The said control means (25) controls intermittently the action | operation of the said compressor (11) based on the detected temperature of the said temperature detection means (24, 24a, 24b), The one of Claim 1 thru | or 4 characterized by the above-mentioned. A cycle using the ejector according to one. The control means (25) switches the open / close means (16, 17e) from an open state to a closed state prior to the stop of the compressor (11), and the compression means (16, 17e) is closed when the open / close means (16, 17e) is closed. The cycle using the ejector according to any one of claims 1 to 5, wherein the operation state of the machine (11) is continued for a predetermined time, and then the compressor (11) is stopped. The throttle mechanism (15, 20, 20a) is disposed upstream of the opening / closing means (16, 17e), and depressurizes the upstream refrigerant of the opening / closing means (16, 17e) so as to be in a gas-liquid two-phase state. A cycle using the ejector according to any one of claims 1 to 6. The cycle using the ejector according to any one of claims 1 to 7, wherein the ejector (17) and the on-off valve (16) are assembled as at least an integral part. A compressor (11) for sucking and compressing refrigerant;
A radiator (13) that radiates heat of the high-pressure refrigerant discharged from the compressor (11);
The radiator (13) has a refrigerant suction port (17b) for decompressing and expanding the refrigerant on the downstream side, and sucking the refrigerant into the interior by the high-speed refrigerant flow at the time of expansion, and from the refrigerant suction port (17b) An ejector (17) for mixing the suction refrigerant and the high-speed refrigerant flow, decelerating the mixed refrigerant flow and increasing the pressure of the refrigerant flow;
A first evaporator (21) for evaporating the refrigerant flowing out of the ejector (17);
A second evaporator (34) connected to a refrigerant passage for branching the refrigerant flow from the ejector (17) to the first evaporator (21) and evaporating the refrigerant flowing out of the ejector (17). When,
Open / close means (16, 17e) capable of preventing refrigerant from flowing into the ejector (17);
Control means (25) for intermittently controlling the operation of the compressor (11),
The control means (25) closes the opening / closing means (16, 17e) within a period during which the operation of the compressor (11) is stopped, and the refrigerant upstream of the opening / closing means (16, 17e) is transferred to the ejector. (17) A cycle using an ejector characterized by preventing the flow into the flow path on the side.

Images