JPH05322336A - Freezing cycle - Google Patents

Abstract

PURPOSE:To provide a freezing cycle in which a shock sound generated when an opening or closing means is opened is reduced. CONSTITUTION:A refrigerant pipe 12b branched at a downstream end of a receiver 4 and communicated with a rear side expansion valve 9 is provided with a solenoid valve 13 at an upstream side of the rear side expansion valve 9. A rear side condensor 11 receiving blown air from a cooling fan 18, condensing and liquefying passing refrigerant is arranged at an upstream side of the solenoid valve 13. The solenoid valve 13 is electrically energized through an air controller controlling device 14 after turning-on a rear air controller switch, after the cooling fan 18 is electrically energized and after a certain time (for example, about 5 seconds) elapses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle equipped with a plurality of refrigerant evaporators.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner mounted on a passenger car, a wagon car, etc., there is a dual air conditioner system capable of independently cooling the front side and the rear side. As shown in FIG. 4, the refrigeration cycle constituting this system has a refrigerant compressor 100, a refrigerant condenser 101, and a receiver 102 connected in series, and a front side evaporator between the receiver 102 and the refrigerant compressor 100. 103 and the rear side evaporator 104 are connected in parallel, and each evaporator 103,
A front side expansion valve 105 and a rear side expansion valve 106 are arranged upstream of 104, respectively. Further, upstream of the rear expansion valve 106, an electromagnetic valve 108 for opening and closing a refrigerant flow path 107 communicating with the rear expansion valve 106 is provided. By closing the electromagnetic valve 108, the receiver 102 is closed.
The more outflowed refrigerant flows only to the front expansion valve 105 and causes only the front evaporator 103 to work, whereby the front side isolated operation can be performed.

[0003]

However, in the refrigeration cycle mounted on a vehicle, functional components such as the refrigerant compressor 100, the refrigerant condenser 101, and the receiver 102 are arranged in the engine room of the vehicle. The piping distance from the receiver 102 to the rear expansion valve 106 is longer than the piping distance from the receiver 102 to the front expansion valve 105, and the pressure loss becomes large. Therefore, the receiver 1
The refrigerant guided from 02 to the rear expansion valve 106 is gasified when flowing through the pipe, so that the high pressure on the rear side becomes higher than that on the front side. Therefore, if the solenoid valve 108 is opened to perform the rear operation while the front operation is being performed independently, the high-pressure refrigerant that has been blocked by the solenoid valve 108 until then is transferred to the rear expansion valve 106. There is a problem that an impact sound is generated when the temperature reaches. In addition,
It has been found that this impact sound becomes louder as the high pressure increases, as shown in FIG. The present invention has been made based on the above circumstances, and an object thereof is to provide a refrigeration cycle in which impact noise generated when the opening / closing means is opened is reduced.

[0004]

In order to achieve the above object, the present invention has a plurality of refrigerant flow paths connected in parallel between a downstream side of a refrigerant condenser and an upstream side of a refrigerant compressor, In a refrigerating cycle in which a pressure reducing means and a refrigerant evaporator are arranged in series in each of the refrigerant flow paths, and an opening / closing means for opening / closing the refrigerant flow path is provided upstream of at least one of the pressure reducing means. A sub-refrigerant condenser that condenses and liquefies the refrigerant that passes by receiving the air blown by the air blowing means, and operates the air blowing means and the opening and closing means, upstream of the opening and closing means of the refrigerant flow path that is opened and closed by the opening and closing means. The control means controls the opening / closing means so as to open the refrigerant flow path after operating the air blowing means.

[0005]

In the refrigerating cycle of the present invention having the above-mentioned structure, by opening the opening / closing means provided in the refrigerant passage, the refrigerant which has been stopped by the opening / closing means flows to the pressure reducing means arranged downstream of the opening / closing means. .. At this time, the control means actuates the air blowing means for blowing air to the sub-refrigerant condenser before opening the opening / closing means to condense and liquefy the refrigerant in the sub-refrigerant condenser, whereby the refrigerant pressure (high pressure Pressure) decreases.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the refrigeration cycle of the present invention applied to an air conditioner for a vehicle will be described with reference to FIGS. FIG. 1 is a refrigeration cycle diagram of this embodiment. The vehicle air conditioner of the present invention employs a dual air conditioner system having a cooling unit (described below) on each of the front side and the rear side of the vehicle. The refrigeration cycle 1 that constitutes this system includes a refrigerant compressor 2,
The refrigerant condenser 3, the receiver 4, the front side expansion valve 6 (the pressure reducing means of the present invention) and the front side evaporator 7 (the refrigerant evaporator of the present invention) constituting the front side cooling unit 5,
A rear expansion valve 9 (pressure reducing means of the present invention) that constitutes the rear cooling unit 8, a rear evaporator 10 (refrigerant evaporator of the present invention), and a rear condenser 11 (sub-refrigerant condenser of the present invention). ) Consists of.

Refrigerant compressor 2, refrigerant condenser 3, receiver 4
Are arranged in the engine room and connected in series by a refrigerant pipe 12, the front cooling unit 5 is installed in front of the passenger seat in the vehicle compartment, and the rear cooling unit 8 is installed in the trunk room. And
The front side evaporator 7 and the rear side evaporator 10 are connected to the receiver 4
Between the downstream side of the refrigerant and the upstream side of the refrigerant compressor 2
The front side expansion valve 6 and the rear side expansion valve 9 are arranged upstream of the evaporators 7 and 10, respectively, and are connected in parallel by a and 12b (refrigerant flow paths of the present invention). An electromagnetic valve 13 (opening / closing means of the present invention) is arranged upstream of the rear expansion valve 9 in the refrigerant pipe 12b which branches off downstream of the receiver 4 and communicates with the rear expansion valve 9. The above-mentioned rear side condenser 11 is provided upstream. The solenoid valve 13 is energized by the air conditioner controller 14 (control means of the present invention), and opens when energized.

The refrigerant compressor 2 is driven by the vehicle engine via the electromagnetic clutch 2a, and compresses and discharges the sucked refrigerant. The refrigerant condenser 3 cools the high-temperature, high-pressure gas refrigerant discharged from the refrigerant compressor 2 into the cooling fan 15
It is condensed and liquefied by receiving the blast of. The receiver 4 temporarily stores the refrigerant guided from the refrigerant condenser 3, and flows out only the liquid refrigerant according to the heat load. The front-side expansion valve 6 and the rear-side expansion valve 9 decompress and expand the refrigerant guided from the receiver 4, respectively, to form a low-temperature, low-pressure atomized refrigerant. The front-side evaporator 7 and the rear-side evaporator 10 heat-exchange the mist-like refrigerant decompressed by the front-side expansion valve 6 and the rear-side expansion valve 9 with ambient air to evaporate it. The air cooled by heat exchange with the refrigerant is blown into the vehicle interior by the blowers 16 and 17, respectively. The rear side condenser 11 receives the air blow of the cooling fan 18 (the air blower of the present invention) whose energization is controlled by the air conditioner controller 14,
The refrigerant that passes through is condensed and liquefied. The rear-side condenser 11 has a core area of about 1/2 to 1/3 of the refrigerant condenser 3, is provided immediately upstream of the solenoid valve 13, and together with the rear-side cooling unit 8 and the cooling fan 18. It is installed in the trunk room (the rear condenser 11 and the cooling fan 18 may be installed in the engine room).

The air conditioner control device 14 operates the refrigerant compressor 2 (on / off control of the electromagnetic clutch 2a) and blowers 16 and 17 by turning on an air conditioner switch (not shown) provided on an air conditioner operation panel (not shown). The air-conditioning switch 18 (not shown) is turned on after the air-conditioner switch is turned on, and the cooling fan 18 and the solenoid valve 13 are energized. .. In addition,
The solenoid valve 13 is energized via the cooling fan 18 through a timer function (not shown) built in the air conditioner control device 14.
After the power is supplied to the device, it is performed after a predetermined time (for example, about 5 seconds) has elapsed.

Next, the operation of this embodiment will be described. When the air conditioner switch is turned on, the refrigerant compressor 2 is activated and the refrigerant circulates in the refrigeration cycle 1. Here, when the rear air conditioner switch is off, the solenoid valve 13
Is closed, the liquid refrigerant flowing out of the receiver 4
It flows only to the front side expansion valve 6 through the refrigerant pipe 12a. The refrigerant decompressed by the front side expansion valve 6 is
After being evaporated in the front side evaporator 7, the refrigerant compressor 2 is sucked. The air cooled by heat exchange with the refrigerant in the front side evaporator 7 is blown into the vehicle interior by the operation of the blower 16. When the rear air conditioner switch is turned on while the air conditioner switch is turned on, the cooling fan 18 is activated at the same time when the switch is turned on to start blowing air to the rear side condenser 11. In the rear condenser 11, the cooling fan 1
In response to the blowing of air, the refrigerant inside the rear condenser 11 is condensed and liquefied. Then, the solenoid valve 13 is opened after a lapse of a predetermined time from the operation of the cooling fan 18, so that the refrigerant, which has been stopped by the solenoid valve 13 until then, passes through the solenoid valve 13 and is guided to the rear expansion valve 9. The refrigerant decompressed by the rear expansion valve 9 evaporates by heat exchange with air in the rear evaporator 10, and is sucked into the refrigerant compressor 2 together with the refrigerant evaporated in the front evaporator 7. The air cooled by the rear evaporator 10 is blown into the passenger compartment by the operation of the blower 17.

As described above, when the rear air conditioner switch is turned on and the rear side cooling unit 8 is operated, the cooling fan 18 is operated before opening the solenoid valve 13, and the rear side condenser 11 is operated. The high pressure on the rear side can be reduced by condensing and liquefying the gas refrigerant inside. Here, the magnitude of fluctuation of the high pressure when the solenoid valve 13 is opened is shown in FIGS. 2 and 3. In addition, FIG. 2 shows the magnitude of pressure fluctuation when the high pressure is 15 kg / cm ² .
FIG. 3 shows the magnitude of pressure fluctuation when the high pressure is 25 kg / cm ² . 2 and 3, it can be seen that the magnitude of the pressure fluctuation shown in FIG. 3 where the high pressure is high is smaller than the magnitude of the pressure fluctuation shown in FIG. 2 where the high pressure is low. That is,
It can be said that the higher the high-pressure pressure, the greater the pressure fluctuation when the solenoid valve 13 is opened and the louder the impact noise (see FIG. 5). Therefore, when the cooling unit 8 on the rear side is operated as in this embodiment, the high-pressure pressure on the rear side is reduced to reduce the impact noise generated when the solenoid valve 13 is opened. ..

[Modification] In this embodiment, the rear cooling unit works by turning on the rear air conditioner switch while the air conditioner switch is on.
An electromagnetic valve 13 is provided upstream of the front expansion valve 6 so that the electromagnetic valve 13 is closed when the air conditioner switch is off, so that the rear air conditioner switch is turned on even when the air conditioner switch is off. The cooling unit 8 may be controlled to operate. The refrigeration cycle 1 of the present invention is applied to a vehicle air conditioner that employs a dual air conditioner system, but it is applied to a refrigeration vehicle equipped with a cool box as a refrigeration cycle for cooling the vehicle compartment and refrigerating inside the cool box. You can also Further, in this embodiment, the refrigeration cycle 1 having two refrigerant evaporators including the front side evaporator 7 and the rear side evaporator 10 is shown, but the refrigeration cycle in which three or more refrigerant evaporators are connected in parallel is shown. But good.

[0013]

In the refrigeration cycle of the present invention, the high pressure pressure on the upstream side of the opening / closing means is reduced by the function of the sub-refrigerant condenser provided upstream of the opening / closing means, and the impact noise generated when the opening / closing means is opened. Can be made smaller.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram according to the present embodiment.

FIG. 2 is a graph showing the magnitude of fluctuations in high pressure when the solenoid valve according to the present embodiment is opened.

FIG. 3 is a graph showing the magnitude of fluctuations in high pressure when the solenoid valve according to the present embodiment is opened.

FIG. 4 is a refrigeration cycle diagram according to a conventional technique.

FIG. 5 is a graph showing the relationship between high pressure and impact noise.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 2 Refrigerant compressor 3 Refrigerant condenser 6 Front side expansion valve (pressure reducing means) 7 Front side evaporator (refrigerant evaporator) 9 Rear side expansion valve (pressure reducing means) 10 Rear side evaporator (refrigerant evaporator) 11 Rear side condenser (sub-refrigerant condenser) 12a Refrigerant piping (refrigerant flow path) 12b Refrigerant piping (refrigerant flow path) 13 Electromagnetic valve (opening / closing means) 14 Air conditioner control device (control means) 18 Cooling fan (blowing means)

Claims (1)

[Claims] 1. A plurality of refrigerant flow paths connected in parallel between a downstream side of a refrigerant condenser and an upstream side of a refrigerant compressor, wherein a pressure reducing means and a refrigerant evaporator are connected in series to each of the refrigerant flow paths. In the refrigeration cycle, the opening / closing means for opening / closing the refrigerant flow path is provided upstream of at least one of the pressure reducing means, and the opening / closing means for opening / closing the refrigerant flow path is opened / closed by the opening / closing means. An upstream sub-refrigerant condenser for condensing and liquefying the refrigerant passing by the air blowing means is provided upstream, and a control means for controlling the operation of the air blowing means and the opening / closing means is provided, and the control means is the air blowing means. A refrigerating cycle, wherein the opening / closing means is controlled so as to open the refrigerant flow path after operating.