JP2020106174A - Refrigeration cycle device - Google Patents

Abstract

To avoid insufficiency of refrigeration oil in a compressor at the time of activation after stop for a long period, with a simple configuration.SOLUTION: A refrigeration cycle device is configured such that a plurality of component devices 10 to 13 comprising an outdoor heat exchanger 11 for condensing refrigerant, and a compressor 10 for compressing refrigerant and discharging it toward the outdoor heat exchanger 11 are connected in an annular manner by a pipe 14, and refrigerant is circulated in a predetermined refrigerant flow direction by operating the compressor 10. The refrigerant cycle device is provided with an inclined part 14a in the pipe connecting the compressor 10 and an upstream-side component device 13 located upstream of the compressor 10 in the refrigerant flow direction. The inclined part 14a is inclined so as to become higher toward the downstream side in the refrigerant flow direction.SELECTED DRAWING: Figure 3

Description

The present invention relates to a refrigeration cycle device.

In a refrigeration cycle device in which a compressor, a condenser, an expansion valve, an evaporator, and the like are connected in an annular shape by pipes, a refrigerant circulates in the cycle. Refrigerant oil for lubricating the compressor is mixed in the refrigerant, and a part of the refrigerator oil circulates in the cycle together with the refrigerant. If such a refrigeration cycle apparatus is stopped for a long time, the refrigerating machine oil may flow out from the compressor due to the fluctuation of the outside air temperature, and the refrigerating machine oil in the compressor may run short when the compressor is started.

On the other hand, in Patent Document 1, a storage tank for recovering refrigerating machine oil flowing out from the compressor is provided between the compressor and the condenser, and the refrigerating machine oil recovered in the storage tank is returned to the compressor by its own weight. Is proposed.

JP, 2017-48928, A

However, in the case where the refrigeration cycle apparatus is provided with a storage tank for recovering refrigerating machine oil as in Patent Document 1, the size of the entire apparatus becomes large. For this reason, the installation space of the refrigeration cycle apparatus becomes large, and it becomes difficult to make it compatible with peripheral parts. Further, when a heavy storage tank is provided, a mounting bracket is required to satisfy vibration durability.

The present invention has been made in view of the above points, and an object thereof is to avoid a shortage of refrigerating machine oil in a compressor at the time of start-up after a long time stop.

In order to achieve the above object, in the invention according to claim 1, a plurality of constituent devices (10 to 13) including an outdoor heat exchanger (11) and a compressor (10) are annularly formed by a pipe (14). A refrigeration cycle device which is connected and in which a refrigerant circulates in a predetermined refrigerant flow direction when the compressor operates, and is a compressor and an upstream side that is a component device located upstream of the compressor in the refrigerant flow direction. A pipe connecting the constituent device (13) is provided with an inclined portion (14a) inclined so as to become higher toward the downstream side in the refrigerant flow direction.

With this inclined portion, the refrigerating machine oil existing on the upstream side in the refrigerant flow direction of the compressor when the operation of the compressor is stopped is not affected by the fluctuation of the outside temperature until the compressor is started, and the compressor and the upstream side configuration are It can be held inside the piping that connects the equipment.

The refrigerating machine oil held in the pipe connecting the compressor and the upstream-side component device is present at a position close to the compressor in the refrigerant flow direction. Therefore, when the compressor is started after being stopped for a long time, the refrigerating machine oil is promptly supplied to the compressor, and it is possible to avoid a shortage of the refrigerating machine oil in the compressor.

It should be noted that the reference numerals in parentheses of the above-mentioned respective constituent elements show the corresponding relationship with the concrete means described in the embodiments described later.

It is the whole refrigerating cycle device lineblock diagram concerning the embodiment of the present invention. It is a figure for demonstrating outflow of the refrigerator oil from a compressor. It is a figure showing a compressor, an evaporator, and piping which connects these.

An embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, the refrigeration cycle device 1 of the present invention is applied to a vehicle air conditioner. In the vehicle air conditioner, the refrigeration cycle apparatus 1 of the present embodiment cools blown air that is blown into the vehicle interior in order to perform air conditioning of the vehicle interior that is the air conditioning target space.

As shown in FIG. 1, the refrigeration cycle apparatus 1 includes constituent devices including a compressor 10, a condenser 11, an expansion valve 12, and an evaporator 13. Each of the constituent devices 10 to 13 is annularly connected by a pipe 14, and when the compressor 10 operates, the refrigerant circulates in a predetermined refrigerant flow direction. Specifically, due to the operation of the compressor 10, the refrigerant circulates in the order of the compressor 10→condenser 11→expansion valve 12→evaporator 13. The refrigerant flow direction in this specification indicates the refrigerant flow direction during operation of the compressor 10.

As the refrigerant, for example, an HFC refrigerant such as R134a or an HFO refrigerant such as R1234yf can be used. Refrigerant oil for lubricating the compressor 10 is mixed in the refrigerant. As the refrigerator oil, for example, PAG oil (polyalkylene glycol oil) can be used. PAG oil has compatibility with a liquid-phase refrigerant. A part of the refrigerating machine oil circulates in the cycle together with the refrigerant.

The compressor 10 compresses the refrigerant sucked from the suction port and discharges it as a high-pressure refrigerant from the discharge port. The suction side of the compressor 10 is connected to the evaporator 13, and the suction side of the compressor 10 is connected to the condenser 11. During operation of the compressor 10, the sliding portion of the compressor 10 is lubricated by the refrigerating machine oil contained in the refrigerant.

The compressor 10 is arranged in the engine room together with the engine 20. The compressor 10 of the present embodiment is driven by the rotational driving force output from the engine 20 via a pulley, a belt and the like.

The condenser 11 heat-exchanges the high-temperature high-pressure refrigerant compressed by the compressor 10 and the outside air blown by the cooling fan 11a, thereby radiating and cooling the high-pressure refrigerant. The radiator 12 is an outdoor heat exchanger arranged on the front side of a radiator (not shown) on the front side of the vehicle in the engine room. The condenser 11 is arranged closer to the outside of the vehicle than the compressor 10.

The expansion valve 12 reduces the pressure of the refrigerant flowing out from the radiator 11. The expansion valve 12 has a temperature sensing unit that detects the superheat degree of the evaporator 13 outlet side refrigerant based on the temperature and pressure of the evaporator 13 outlet side refrigerant, and the evaporator 13 outlet side refrigerant superheat degree is predetermined. A thermal expansion valve that adjusts the throttle opening degree by a mechanical mechanism so as to be within the reference range can be used.

The evaporator 13 exchanges heat between the low pressure refrigerant decompressed by the expansion valve 12 and the blown air to evaporate the low pressure refrigerant and exert an endothermic effect. The evaporator 13 corresponds to the upstream component device of the present invention.

The evaporator 13 is an indoor heat exchanger arranged in the casing 31 of the indoor air conditioning unit 30. In the casing 31, the blower fan 32, the evaporator 13, and the heater core 21 are arranged in this order from the upstream side of the air flow. The temperature of the conditioned air blown by the blower fan 32 is adjusted by the evaporator 13 and the heater core 21, and is supplied into the vehicle interior.

Here, the outflow of refrigerating machine oil from the compressor 10 when the refrigeration cycle apparatus 1 is stopped for a long time will be described with reference to FIG.

By stopping the operation of the compressor 10, the refrigerant in the cycle stops circulating. The vapor phase refrigerant is cooled and condensed to become a liquid phase refrigerant. Refrigerating machine oil and liquid-phase refrigerant are in a compatible state. When the outside air temperature decreases at night, for example, with the compressor 10 stopped, the ambient temperature on the condenser 11 side becomes lower than that on the compressor 10 side, and the refrigerant pressure on the condenser 11 side is the refrigerant pressure on the compressor 10 side. Will be lower. Due to this refrigerant pressure difference, as shown in FIG. 2A, the liquid-phase refrigerant in the compressor 10 flows out together with the refrigerating machine oil to the condenser 11 side.

Then, for example, when the outside air temperature rises during the daytime, the ambient temperature of the condenser 11 and the evaporator 13 side becomes higher than that of the compressor 10 side, and the refrigerant pressure of the condenser 11 and the evaporator 13 side becomes the compressor 10 side. Higher than the refrigerant pressure. Due to this refrigerant pressure difference, the gas-phase refrigerant flows into the compressor 10 as shown in FIG. Since the vapor phase refrigerant is separated from the refrigeration oil, only the vapor phase refrigerant flows into the compressor 10.

After that, as shown in FIGS. 2C and 2D, the outside air temperature is repeatedly decreased and increased, so that the liquid-phase refrigerant and the refrigerating machine oil flow out from the compressor 10 and the outside air temperature to the compressor 10. The inflow of the vapor phase refrigerant is repeated. Therefore, the longer the stop time of the compressor 10 is, the less the refrigerating machine oil in the compressor 10 is.

As described above, the refrigerating machine oil in the compressor 10 flows out to the condenser 11 side due to the fluctuation of the outside air temperature. The refrigerating machine oil flowing out from the compressor 10 exists at the farthest position from the compressor 10 in the refrigerant flow direction. Therefore, it takes time for the refrigerating machine oil flowing out of the compressor 10 to circulate in the compressor 10 after starting the compressor 10.

Next, the pipe 14 that connects the compressor 10 and the evaporator 13 will be described. As shown in FIG. 3, the pipe 14 that connects the compressor 10 and the evaporator 13 is provided with a first inclined portion 14a that is inclined so as to become higher toward the downstream side in the refrigerant flow direction. The first inclined portion 14a is provided on the upstream side of the compressor 10 in the refrigerant flow direction. The first inclined portion 14a corresponds to the inclined portion of the present invention.

A first upper end portion 14b protruding upward in the vertical direction is provided at an end portion of the pipe 14 on the downstream side in the refrigerant flow direction of the first inclined portion 14a. A lower end portion 14c protruding downward in the vertical direction is provided at an end portion of the pipe 14 on the upstream side in the refrigerant flow direction of the first inclined portion 14a. The first upper end portion 14b is provided at a position higher than the lower end portion 14c. The compressor 10 of the present embodiment is located below the first upper end portion 14b.

On the upstream side of the lower end portion 14c of the pipe 14 in the refrigerant flow direction, a second inclined portion 14d that is inclined so as to become higher toward the upstream side of the refrigerant flow direction is provided. The first inclined portion 14a and the second inclined portion 14d sandwiching the lower end portion 14c are formed in a V shape protruding downward in the vertical direction. The second inclined portion 14d corresponds to the upstream inclined portion of the present invention.

A second upper end portion 14e protruding upward in the vertical direction is provided on the upstream side of the second inclined portion 14d in the pipe 14 in the refrigerant flow direction. The second upper end portion 14e is located above the lower end portion 14c. The evaporator 13 of this embodiment is located below the second upper end portion 14e.

During operation of the compressor 10, the refrigerant and the refrigerating machine oil circulate throughout the refrigeration cycle apparatus 1. Refrigerating machine oil existing on the upstream side in the refrigerant flow direction of the compressor 10 when the operation of the compressor 10 is stopped is prevented from moving toward the compressor 10 by the first inclined portion 14a of the pipe 14. Therefore, the refrigerating machine oil existing on the upstream side in the refrigerant flow direction of the compressor 10 when the operation of the compressor 10 is stopped is stored in the pipe 14 that connects the compressor 10 and the evaporator 13.

As the vertical height H of the first inclined portion 14a is higher, the amount of refrigerating machine oil that can be stored inside the pipe 14 that connects the compressor 10 and the evaporator 13 can be increased. Further, as the vertical height H of the first inclined portion 14a is higher, the movement of the refrigerating machine oil toward the compressor 10 side is hindered. The vertical height H of the first inclined portion 14a is the vertical height from the lower end portion 14c to the first upper end portion 14b.

The vertical height H of the first inclined portion 14a can be arbitrarily set according to the amount of refrigerating machine oil required in the compressor 10 during operation of the compressor 10. In this embodiment, the height H of the first inclined portion 14a in the vertical direction is 80 mm. Further, the inclination angle of the first inclined portion 14a with respect to the horizontal direction may be set so that the first inclined portion 14a is as long as possible.

In the embodiment described above, the pipe 14 that connects the compressor 10 and the evaporator 13 is provided with the first inclined portion 14a that inclines so as to become higher toward the refrigerant flow downstream side. Thereby, the refrigerating machine oil can be stored in the pipe 14 connecting the compressor 10 and the evaporator 13 after the compressor 10 is stopped. The refrigerating machine oil stored in the pipe 14 that connects the compressor 10 and the evaporator 13 is retained in the pipe 14 without being affected by the fluctuation of the outside temperature until the compressor 10 is activated.

The refrigerating machine oil held in the pipe 14 connecting the compressor 10 and the evaporator 13 exists at a position close to the compressor 10 in the refrigerant flow direction. Therefore, when the compressor 10 is started after being stopped for a long time, the refrigerating machine oil is promptly supplied to the compressor 10, so that the compressor 10 can be prevented from running out of the refrigerating machine oil. This makes it possible to avoid a shortage of refrigerating machine oil in the compressor 10 immediately after startup with a simple configuration in which the first inclined portion 14a is provided.

Further, in the present embodiment, the second inclined portion 14d that is inclined so as to be higher toward the refrigerant flow upstream side is provided on the refrigerant flow upstream side than the lower end portion 14c. Therefore, the refrigerating machine oil existing in the pipe 14 connecting the compressor 10 and the evaporator 13 can be prevented from flowing into the evaporator 13, and the refrigerating machine oil can be retained in the pipe 14. As a result, the refrigerating machine oil can be supplied to the compressor 10 immediately after the compressor 10 is started.

In addition, in the present embodiment, since the first inclined portion 14a and the second inclined portion 14d that sandwich the lower end portion 14c are V-shaped, they can be stored in the pipe 14 that connects the compressor 10 and the evaporator 13. The amount of refrigerating machine oil can be increased.

(Other embodiments)
The present invention is not limited to the above-described embodiments, but can be variously modified as follows without departing from the spirit of the present invention.

(1) In the above-described embodiment, an example in which the upstream component device located upstream in the refrigerant flow direction of the compressor 10 is the evaporator 13 has been described, but the invention is not limited to this, and the upstream component device is the evaporator 13. May be different components. In this case, the inclined portions 14a, 14d and the like may be provided in the pipe 14 that connects the compressor 10 and the upstream component equipment different from the evaporator 13.

(2) In the above embodiment, the compressor 10 is provided at a position lower than the first upper end portion 14b, but the first upper end portion 14b and the compressor 10 may have the same height, or the first upper end portion 14b. The compressor 10 may be higher than the compressor 10.

(3) In the above embodiment, the evaporator 13 is provided at a position lower than the second upper end 14e, but the second upper end 14e and the evaporator 13 may have the same height, or the second upper end 14e. The evaporator 13 may be higher than the above.

10 Compressor 11 Condenser (outdoor heat exchanger)
12 Expansion valve 13 Evaporator (upstream component equipment, indoor heat exchanger)
14 Piping 14a 1st inclined part (inclined part)
14c Lower end portion 14d Second inclined portion (upstream side inclined portion)

Claims (3)

Plural component devices (10 to 13) including an outdoor heat exchanger (11) that condenses the refrigerant and a compressor (10) that compresses the refrigerant and discharges the refrigerant toward the outdoor heat exchanger are pipes (14). ) Is connected in a ring shape, the refrigerant is circulated in a predetermined refrigerant flow direction by operating the compressor, a refrigeration cycle device,
In the pipe that connects the compressor and the upstream-side component device (13) that is the component device located upstream of the compressor in the refrigerant flow direction, toward the downstream side in the refrigerant flow direction. A refrigeration cycle apparatus provided with an inclined portion (14a) inclined so as to be higher. In the pipe connecting the compressor and the upstream component, a lower end portion (14c) protruding downward in the vertical direction is provided on the upstream side of the inclined portion in the refrigerant flow direction. The refrigeration cycle apparatus according to 1. In the pipe that connects the compressor and the upstream-side component device, on the upstream side in the refrigerant flow direction of the lower end portion, an upstream-side inclined portion that is inclined so as to become higher toward the refrigerant flow direction upstream side ( 14d) is provided, The refrigerating-cycle apparatus of Claim 2.

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