JP2012072950A - Refrigeration cycle system for transport vehicle, and refrigeration cycle system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration cycle system for transport vehicle and a refrigeration cycle system, capable of suppressing the increase of a compressor motive force inexpensively, in a refrigeration cycle system in which a liquid refrigerant is injected to a compressor.SOLUTION: Piping 91 constituting an injection circuit 90 separated from a receiver 80 is installed in a position for getting traveling air flowing in during traveling of a vehicle in a box 110, and a refrigerant flowing in the pipe 91 constituting the injection circuit 90 is cooled by the traveling air to be set in an excessively cooled state. Thus, especially when a compressor 20 is driven by a vehicle traveling engine, by cooling the piping 91 constituting the injection circuit 90 by the traveling air, the injection refrigerant is cooled in linkage with the increase of an engine revolution speed.

Description

  The present invention relates to a refrigeration cycle system and a refrigeration cycle system for transport vehicles such as refrigeration vehicles and refrigeration vehicles.

  As is well known, a refrigeration cycle system for maintaining the interior of a luggage compartment at a predetermined temperature in a refrigerated vehicle, a refrigerated vehicle, etc., liquefies gas refrigerant compressed at a high temperature and high pressure by a compressor by cooling with a condenser. The temperature is adjusted by exchanging heat with the atmosphere in the room or luggage compartment using an evaporator.

  Here, it is necessary to suppress the discharge gas temperature of the compressor below a certain temperature from the viewpoint of compressor protection. Therefore, a discharge gas temperature of the compressor is reduced by injecting (injecting) a part of the liquid refrigerant cooled by the condenser into the compressor (see, for example, Patent Document 1).

JP 2000-320906 A

  However, when liquid refrigerant is injected into the compressor, the mass of refrigerant in the compressor chamber of the compressor increases, so that the power required to drive the compressor (hereinafter referred to as compressor power as appropriate) increases. When the compressor power increases, the power supply capacity of the refrigeration cycle system may be compressed and the operation may be hindered. On the other hand, it is conceivable to increase the power supply capacity of the refrigeration cycle system, but this is not preferable because it directly increases the apparatus cost.

Further, in the case of a compressor driven by a vehicle traveling engine, the rotational speed of the compressor increases in proportion to the increase in the rotational speed of the engine. If the rotation speed of the compressor increases, the amount of liquid refrigerant that needs to be injected into the compressor increases. However, it is not easy to increase the amount of liquid refrigerant to be injected, which may lead to an increase in the size and capacity of the entire system, and may increase the equipment cost.
The present invention has been made based on such a technical problem, and in a refrigeration cycle system for injecting liquid refrigerant into a compressor, a refrigeration cycle system for a transport vehicle capable of suppressing an increase in compressor power at low cost. An object of the present invention is to provide a refrigeration cycle system.

The present invention made for this purpose is a transportation vehicle refrigeration cycle system for cooling a luggage storage provided in a vehicle, which compresses a refrigerant to a high temperature and a high pressure, and condenses the refrigerant. A condenser that liquefies the liquid, an expansion valve that decompresses the liquefied refrigerant, an evaporator that exchanges heat of the refrigerant sent from the expansion valve with the surrounding atmosphere, and a refrigerant that has passed through the condenser is separated into a liquid refrigerant and a gas refrigerant. A receiver, and an injection circuit that injects a part of the liquid refrigerant separated by the receiver into the compressor. The injection circuit is characterized in that the liquid refrigerant in the injection circuit is brought into a supercooled state by running wind generated as the vehicle travels.
Thus, the enthalpy of this refrigerant | coolant can be reduced by making the liquid refrigerant | coolant in an injection circuit into a supercooled state with driving | running | working wind. Then, the compressor cooling effect per unit flow rate of the liquid refrigerant to be injected is increased.

Here, the present invention is particularly effective when the compressor is driven by an engine for traveling the vehicle.
In the case of a compressor driven by an engine, the rotational speed of the compressor increases in proportion to an increase in the rotational speed of the engine. This increases the amount of liquid refrigerant that needs to be injected into the compressor. On the other hand, by cooling the liquid refrigerant with the traveling wind, the traveling speed increases as the engine speed increases and the flow velocity of the traveling wind increases. Therefore, the refrigerant is cooled linked to the increase in the engine speed. be able to.

  Further, the injection circuit includes a throttle part that throttles the flow path of the injection circuit, and the throttle part is the difference between the length of the difference between the refrigerant temperature and the ambient temperature upstream of the throttle part of the injection circuit exposed in the chamber, and the length. It is preferable that the product is provided at a position that exceeds the product of the difference between the refrigerant temperature and the ambient temperature in the downstream portion and the length from the throttle portion of the injection circuit exposed in the chamber.

Further, the refrigeration cycle system according to the present invention forms a compressor that compresses the refrigerant to increase the temperature and pressure, a condenser that condenses and liquefies the refrigerant, an expansion valve that decompresses the liquefied refrigerant, and a space to be cooled. Installed in the storage chamber, an evaporator that exchanges heat of the refrigerant sent from the expansion valve with the surrounding atmosphere, a receiver that separates the refrigerant that has passed through the condenser into liquid refrigerant and gas refrigerant, and liquid that is separated by the receiver And an injection circuit for injecting a part of the refrigerant into the compressor, wherein the injection circuit is provided through the interior of the storage.
In such a refrigeration cycle system, the liquid refrigerant in the injection circuit can be cooled and the enthalpy of the refrigerant can be reduced by providing the injection circuit in a chamber in which the internal atmosphere is cooled by the evaporator. Then, the compressor cooling effect per unit flow rate of the liquid refrigerant to be injected is increased.
Such a refrigeration cycle system is not limited to a refrigeration cycle system for transportation vehicles, but can be applied to refrigeration cycle systems for other uses.

  Further, the injection circuit in this refrigeration cycle system includes a throttle part that throttles the flow path of the injection circuit, and the throttle part is the difference between the refrigerant temperature and the ambient temperature upstream of the throttle part of the injection circuit exposed in the chamber. It is desirable that the product of the length is provided at a position that exceeds the product of the difference between the refrigerant temperature and the ambient temperature in the downstream portion and the length of the throttle portion of the injection circuit exposed in the chamber.

According to the present invention, the enthalpy of the refrigerant can be reduced by cooling the liquid refrigerant. Then, the compressor cooling effect per unit flow rate of the liquid refrigerant to be injected is increased. As a result, the amount of injection refrigerant necessary for cooling the compressor can be reduced. Accordingly, it is possible to suppress an increase in compressor power due to liquid refrigerant injection.
Further, since it is only necessary to change the piping path without adding a special device or equipment in order to cool the liquid refrigerant to be injected, an effective effect can be obtained at a low cost.

It is a figure which shows the structure of the refrigerating cycle system in 1st Embodiment. It is sectional drawing which shows arrangement | positioning of an injection circuit. It is a figure which shows the refrigerant | coolant temperature and enthalpy distribution at the time of providing the aperture | diaphragm | squeeze part of an injection circuit in the intermediate position in the area | region where driving | running | working wind hits. It is a figure which shows distribution of refrigerant | coolant temperature and enthalpy when the aperture | diaphragm | squeeze part of an injection circuit is provided in the downstream rather than the intermediate position in the area | region where driving | running | working wind hits. It is a figure which shows the structure of the refrigerating-cycle system in 2nd Embodiment. It is a figure which shows distribution of the refrigerant | coolant temperature and enthalpy at the time of providing the aperture | diaphragm | squeeze part of an injection circuit in the intermediate position in the area | region exposed in a store | warehouse | chamber. It is a figure which shows the refrigerant | coolant temperature and distribution of enthalpy at the time of providing the aperture | diaphragm | squeeze part of an injection circuit in the upstream from the intermediate position in the area | region exposed in a store | warehouse | chamber. It is a figure which shows the structure at the time of providing the aperture | diaphragm | squeeze part of an injection circuit in the injection circuit after leaving a luggage storage. It is a figure which shows the refrigerant | coolant temperature and distribution of enthalpy at the time of providing the aperture | diaphragm | squeeze part of an injection circuit in the injection circuit after leaving a luggage storage. It is a figure which shows the modification of an injection circuit.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
[First Embodiment]
FIG. 1 is a diagram for explaining a configuration of a refrigeration cycle system (transportation vehicle refrigeration cycle system) 10A according to the present embodiment.
The refrigeration cycle system 10A in the present embodiment is mounted in a luggage compartment 100 such as a vehicle interior, a freezer car, and a refrigerator car. This refrigeration cycle system 10A includes a compressor 20 that compresses refrigerant into high-temperature and high-pressure gas, a condenser 30 that cools and liquefies high-temperature and high-pressure refrigerant with outside air, and an expansion valve 40 that reduces the pressure of the refrigerant. The evaporator 50 removes heat from the air in the room or luggage and evaporates the refrigerant, and the liquid-phase refrigerant is separated from the gas-liquid two-phase refrigerant that has passed through the evaporator 50, and only the gas-phase refrigerant is compressed into the compressor 20. And an accumulator 60 that supplies the refrigerant, and a refrigerant pipe 70 for circulating the refrigerant between them.
Further, the refrigeration cycle system 10 </ b> A includes a receiver 80 that separates the refrigerant into liquid refrigerant and gas refrigerant on the outlet side of the condenser 30. A part of the liquid refrigerant separated by the receiver 80 is injected in the middle of the compression process of the compressor 20 through the injection circuit 90.

In such a refrigeration cycle system 10 </ b> A, at least the evaporator 50 is installed in the luggage storage 100 such as a freezer car or a refrigerator car, and at least the compressor 20, the condenser 30, and the receiver 80 are installed outside the luggage storage 100. Note that the evaporator 50 and the condenser 30 are provided with fans 51 and 31, respectively, in order to force heat exchange.
Here, as shown in FIGS. 1 and 2, a box 110 that houses at least the compressor 20, the condenser 30, and the receiver 80 is provided on the front surface 100 a facing the front in the traveling direction of the luggage storage 100. An opening 111 for taking in air from the outside is formed on the front surface of the box 110.

  As shown in FIG. 2, in the present embodiment, the pipe 91 constituting the injection circuit 90 separated from the receiver 80 is installed in the box 110 at a position where the traveling wind that flows from the opening 111 during the traveling of the vehicle hits. To do. However, here, the pipe 91 is provided at a position that does not block the front surface of the capacitor 30. This is because if the pipe 91 blocks the front surface of the capacitor 30, the heat exchange efficiency in the capacitor 30 decreases.

  In such a configuration, the refrigerant flowing in the pipe 91 that constitutes the injection circuit 90 is cooled by the traveling wind and becomes a supercooled state. When the refrigerant to be injected (hereinafter referred to as an injection refrigerant as appropriate) is cooled, the enthalpy of the refrigerant decreases. When the enthalpy of the injection refrigerant decreases, the compressor cooling effect per unit flow rate of the injection refrigerant increases. As a result, the amount of injection refrigerant required for cooling the compressor 20 can be reduced. Accordingly, it is possible to suppress an increase in compressor power due to liquid refrigerant injection.

  The configuration in the first embodiment as described above is particularly effective when the compressor 20 is driven by a vehicle running engine. As described above, in the case of the compressor 20 driven by the engine, when the rotational speed of the compressor 20 increases in proportion to the increase in the rotational speed of the engine, the amount of liquid refrigerant that needs to be injected into the compressor 20 Will increase. On the other hand, in the configuration of the present embodiment, the pipe 91 that constitutes the injection circuit 90 is cooled by the traveling wind, so that the wind speed of the traveling wind increases as the traveling speed increases, which is linked to an increase in the engine speed. Thus, the injection refrigerant can be cooled, and the amount of the injection refrigerant necessary for cooling the compressor 20 can be reduced accordingly. Accordingly, it is possible to effectively suppress an increase in compressor power due to liquid refrigerant injection. In addition, according to such a configuration, it is possible to obtain an effective effect at low cost only by changing the piping path without adding a special device or device in order to cool the injection refrigerant.

In the first embodiment, the throttle circuit 200 may be provided in the injection circuit 90. As such a throttle unit 200, a capillary or an orifice can be provided in addition to an electromagnetic valve provided to control ON / OFF of injection from the injection circuit 90 to the compressor 20 and an injection amount.
Here, the branch position from the refrigerant pipe 70 of the injection circuit 90 is a, the connection position of the injection circuit 90 on the upstream side of the throttle unit 200 is c, the connection position of the injection circuit 90 on the downstream side of the throttle unit 200 is d, and the throttle A position where the injection circuit 90 is connected to the compressor 20 on the upstream side of the section 200 is defined as f.
In the injection circuit 90 in the region where the traveling wind hits in the box 110, the length upstream of the throttle unit 200 is L_hi_out, and the length downstream is L_lo_out.

Then, as shown in FIG. 3, in the present embodiment in which the injection circuit 90 is installed outside the luggage storage 100, the throttle unit 200 is installed at an intermediate position of the injection circuit 90 outside the luggage storage 100 (L_hi_out = L_lo_out), the refrigerant that has been, for example, 50 ° C. at the position “a” on the upstream side of the throttle unit 200 is cooled to the position “c” of the throttle unit 200, and is further throttled by the throttle unit 200. The temperature of the refrigerant at the positions d to f decreases to, for example, 15 ° C.
On the other hand, the enthalpy gradually decreases as the refrigerant is cooled from the position a to the position c. Then, after passing through the throttle part 200, the refrigerant is warmed by the outside air toward the position f, and the enthalpy increases. At this time, the enthalpy at the position f is not preferable because it exceeds the enthalpy at the position a.

On the other hand, as shown in FIG. 4, the enthalpy is positioned from the position a by arranging the throttle unit 200 on the downstream side of the intermediate position of the injection circuit 90 outside the luggage storage 100 (L_hi_out> L_lo_out). As the refrigerant is cooled toward c, the enthalpy gradually decreases, and after passing through the throttle portion 200, the refrigerant is warmed by the outside air toward the position f, and the enthalpy increases. At this time, the enthalpy at the position f can be prevented from reaching the enthalpy at the position a.
Therefore, when the throttle unit 200 is provided, the position thereof is preferably as downstream as possible of the injection circuit 90 outside the luggage storage 100.

[Second Embodiment]
Next, a second embodiment of the refrigeration cycle system according to the present invention will be described. Note that the second embodiment described below differs from the first embodiment only in the arrangement of the injection circuit 90 with respect to the configuration shown in the first embodiment. A description will be given, and the description of common configurations will be omitted.
As shown in FIG. 5, in the refrigeration cycle system 10B according to the present embodiment, at least an evaporator 50 is installed in a luggage storage 100 such as a refrigeration vehicle or a refrigerator car, and at least the compressor 20, the capacitor 30, and the receiver 80 are It is installed outside the storage 100.
In the present embodiment, the piping 91 constituting the injection circuit 90 separated from the receiver 80 is installed in the luggage storage 100.

In such a configuration, the refrigerant flowing in the pipe 91 constituting the injection circuit 90 is cooled by the cold air in the luggage storage 100 and is in a supercooled state. When the injection refrigerant is cooled, the enthalpy of the refrigerant is lowered, and the compressor cooling effect per unit flow rate of the injection refrigerant is increased. As a result, the amount of injection refrigerant required for cooling the compressor 20 can be reduced. Accordingly, it is possible to suppress an increase in compressor power due to liquid refrigerant injection.
According to such a configuration, it is possible to obtain an effective effect at low cost only by changing the piping path without adding a special device or equipment in order to cool the injection refrigerant.

  Note that the configuration shown in the present embodiment is not limited to the configuration in which the compressor 20 is driven by the vehicle running engine, but can also be applied to the case where the compressor 20 is acted on by another drive source such as an electric motor. is there.

In the second embodiment, the injection circuit 90 may be provided with a throttle unit 200 such as a solenoid valve, capillary, or orifice.
Here, a position where the injection circuit 90 penetrates the inside and outside of the luggage storage 100 on the downstream side of the throttle unit 200 is assumed to be e. In the injection circuit 90 exposed in the luggage storage 100, the length upstream of the throttle unit 200 is L_hi_in, and the length downstream is L_lo_in.
Then, in this embodiment in which the injection circuit 90 is installed inside the luggage storage 100 as shown in FIG. 5, the throttle part 200 is positioned at the position ac of the injection circuit 90 inside the luggage storage 100 as shown in FIG. 6. The sum of the product and difference (L_hi_in, L_lo_in) of the refrigerant temperature and the ambient temperature at each location between the position and de is the product of the difference between the refrigerant temperature and the ambient temperature and the length (L_lo_out) between the positions ef. When the refrigerant is installed at a position smaller than that, the refrigerant that has been, for example, 50 ° C. at the position “a” on the upstream side of the throttle unit 200 is cooled down to the position “c” of the throttle unit 200 and is further throttled by the throttle unit 200. Thus, the temperature of the refrigerant at the positions d to f after the throttle unit 200 is reduced to 15 ° C., for example.
On the other hand, the enthalpy of the enthalpy is greatly reduced by cooling the refrigerant by the cool air in the luggage 100 from the position a to the position c. After passing through the throttle part 200, the refrigerant is cooled by the cool air in the luggage storage 100 even toward the position e, but the enthalpy reduction between the positions de is smaller than that between the positions ac. Then, the injection circuit 90 exits the luggage storage 100 at the position f and is connected to the compressor 20. At this time, the total enthalpy reduction caused between the positions ac and de is the enthalpy reduction produced between the positions ef. Below the increase. The enthalpy at the position f is not preferable because it is equal to or greater than the enthalpy at the position a.

On the other hand, as shown in FIG. 7, the throttle unit 200 is provided with a difference and length (L_hi_in) between the refrigerant temperature and the ambient temperature at each position between the positions ac and the positions de of the injection circuit 90 inside the luggage storage 100. , L_lo_in) is installed at a position where the sum of the product of the refrigerant temperature and the ambient temperature between the positions ef is larger than the product of the length (L_lo_out), and the refrigerant is moved from the position a to the position c. The enthalpy is significantly reduced by being cooled by the cool air in the luggage storage 100, and after passing through the throttle portion 200, the refrigerant is further cooled by the cool air in the luggage storage 100 toward the position e, and the enthalpy is reduced. . Then, the injection circuit 90 exits the luggage storage 100 at the position f and is connected to the compressor 20. At this time, the total enthalpy reduction caused between the positions ac and de is the enthalpy reduction produced between the positions ef. Over the increase. The enthalpy at position f can be prevented from reaching the enthalpy at position a.
Therefore, when the throttle unit 200 is provided, the position thereof is preferably as downstream as possible of the injection circuit 90 inside the luggage storage 100.
Therefore, as shown in FIG. 8, the throttle unit 200 is installed in the injection circuit 92 after leaving the luggage storage 100, and as shown in FIG. 9, the total enthalpy reduction caused between the positions ae is between the positions ec. And an increase in enthalpy caused between the position df.

In addition, in the said embodiment, although basic structure was shown about refrigeration cycle system 10A, 10B, this is good also as what kind of structure. For example, a multi-type system configuration including a plurality of sets of evaporators 50 may be employed.
Further, in order to increase the heat exchange efficiency in the injection circuit 90, the pipe 91 constituting the injection circuit 90 may be meandered as shown in FIG. 10 (a), or the pipe 91 as shown in FIG. 10 (b). The fins 93 may be provided on the 91, and a part of the pipe 91 may be a heat exchanger 94 as shown in FIG.
Furthermore, the configuration shown in the second embodiment can be applied to a refrigeration cycle system other than a vehicle. For example, the present invention can be applied to a refrigeration cycle system for a house, a facility such as a factory, or a building to remove heat from a heating element used in the house or facility.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

  DESCRIPTION OF SYMBOLS 10A ... Refrigeration cycle system (refrigeration cycle system for transport vehicles), 10B ... Refrigeration cycle system, 20 ... Compressor, 30 ... Condenser, 40 ... Expansion valve, 50 ... Evaporator, 60 ... Accumulator, 70 ... Refrigerant pipe, 80 ... Receiver , 90 ... injection circuit, 91 ... piping, 100 ... luggage storage, 110 ... box, 111 ... opening, 200 ... throttle part

Claims (5)

A refrigeration cycle system for a transportation vehicle that cools a luggage storage provided in the vehicle,
A compressor that compresses the refrigerant to increase the temperature and pressure,
A condenser that condenses and liquefies the refrigerant;
An expansion valve for decompressing the liquefied refrigerant;
An evaporator for exchanging heat of the refrigerant sent from the expansion valve with an ambient atmosphere;
A receiver that separates the refrigerant that has passed through the capacitor into a liquid refrigerant and a gas refrigerant;
An injection circuit for injecting a part of the liquid refrigerant separated by the receiver into the compressor,
The refrigeration cycle system for transport vehicles, wherein the injection circuit causes the liquid refrigerant in the injection circuit to be in a supercooled state by running wind generated as the vehicle travels.   The refrigeration cycle system for a transportation vehicle according to claim 1, wherein the compressor is driven by an engine for traveling the vehicle. The injection circuit includes a throttle portion that throttles the flow path of the injection circuit,
The throttle portion is the throttle portion of the injection circuit where the product of the difference between the refrigerant temperature and the ambient temperature upstream of the throttle portion of the injection circuit exposed in the chamber and the length of the ambient temperature is exposed in the chamber. The transport vehicle refrigeration cycle system according to claim 1, wherein the transport vehicle refrigeration cycle system is provided at a position that exceeds a product of the difference between the refrigerant temperature and the ambient temperature in the downstream portion and the ambient temperature. A compressor that compresses the refrigerant to increase the temperature and pressure,
A condenser that condenses and liquefies the refrigerant;
An expansion valve for decompressing the liquefied refrigerant;
An evaporator that is installed in a cabinet that forms a space to be cooled, and that exchanges heat of the refrigerant sent from the expansion valve with the surrounding atmosphere;
A receiver that separates the refrigerant that has passed through the capacitor into a liquid refrigerant and a gas refrigerant;
An injection circuit for injecting a part of the liquid refrigerant separated by the receiver into the compressor,
The refrigeration cycle system, wherein the injection circuit is provided through the storage. The injection circuit includes a throttle portion that throttles the flow path of the injection circuit,
The throttle portion is the throttle portion of the injection circuit where the product of the difference between the refrigerant temperature and the ambient temperature upstream of the throttle portion of the injection circuit exposed in the chamber and the length of the ambient temperature is exposed in the chamber. 5. The refrigeration cycle system according to claim 4, wherein the refrigeration cycle system is provided at a position that exceeds a product of the difference between the refrigerant temperature and the ambient temperature in the downstream portion and the ambient temperature.

Images