WO2015136654A1

WO2015136654A1 - Refrigerating device

Info

Publication number: WO2015136654A1
Application number: PCT/JP2014/056576
Authority: WO
Inventors: 宮井　純一; 池田　隆; 杉本　猛; 山下　哲也; 亮宜倉地; 祐二垂水; 博文原井川; 勝徳堀内; 幅紀佐藤
Original assignee: 三菱電機株式会社
Priority date: 2014-03-12
Filing date: 2014-03-12
Publication date: 2015-09-17

Abstract

A refrigerating device is characterized by comprising: a high-temperature side refrigerant circuit (A) in which a high-temperature side compressor (1), a high-temperature side condenser (2), a high-temperature side expansion valve (3), and a high-temperature side evaporator (4) are sequentially connected by piping and in which a refrigerant circulates; a low-temperature side refrigerant circuit (B) in which a low-temperature side compressor (7), an intercooler (8), a low-temperature side condenser (9), a low-temperature side expansion valve (16), and a low-temperature side evaporator (17) are sequentially connected by piping and in which a refrigerant circulates; a cascade condenser (13) that comprises the high-temperature side evaporator (4) and the low-temperature side condenser (9) and in which heat exchange is performed between the refrigerant flowing in the high-temperature side evaporator (4) and the refrigerant flowing in the low-temperature side condenser (9); and a blower that supplies air to the high-temperature side condenser (2) and the intercooler (8). The device is also characterized in that at least a portion of the high-temperature side condenser (2) and the intercooler (8) comprise an integrated heat exchanger in which heat transfer fins (42) are integrated.

Description

Refrigeration equipment

The present invention relates to a refrigeration apparatus in which two refrigerant circuits (refrigeration cycles) are cascade-connected.

2. Description of the Related Art Conventionally, a refrigeration apparatus that performs a dual refrigeration cycle by cascade-connecting a high-temperature refrigerant circuit (high-temperature refrigeration cycle) and a low-temperature refrigerant circuit (low-temperature refrigeration cycle) via a cascade capacitor is known.
In such a refrigeration apparatus, a pre-stage radiator (intermediate cooler) that radiates the refrigerant circulating in the low-temperature side refrigerant circuit is provided, and the pre-stage radiator is condensed in the high-temperature side refrigerant circuit in the air passage formed by the blowing means. The thing arrange | positioned in the downstream of a container is proposed (for example, refer patent document 1).

JP 2008-2759 A (paragraph [0029], FIG. 1)

However, in the conventional refrigeration apparatus, the condenser of the high temperature side refrigeration circuit and the intercooler of the low temperature side refrigerant circuit are separately arranged.
Moreover, in the conventional refrigeration apparatus, the condenser of the high temperature side refrigeration circuit and the intercooler of the low temperature side refrigerant circuit are manufactured separately.
For this reason, there has been a problem that it is difficult to balance the heat exchange amount (air volume) of the condenser of the high-temperature side refrigeration circuit and the heat exchange amount (air volume) of the intermediate cooler of the low-temperature side refrigerant circuit.
In addition, there is a problem that the manufacturing cost is increased.

The present invention has been made to solve the above-described problems. The heat exchange amount (air volume) of the condenser of the high-temperature side refrigeration circuit and the heat exchange amount (air volume) of the intermediate cooler of the low-temperature side refrigerant circuit. It is possible to obtain a refrigeration apparatus that is easy to balance.
Moreover, the freezing apparatus which can reduce manufacturing cost is obtained.

The refrigeration apparatus according to the present invention includes a first refrigerant circuit in which a first compressor, a first condenser, a first throttling device, and a first evaporator are sequentially connected by piping, and a refrigerant circulates, a second compressor, an intermediate A cooler, a second condenser, a second expansion device, and a second evaporator are sequentially connected to each other by pipes, the refrigerant is circulated, the first evaporator, and the second condenser; A cascade condenser that exchanges heat between the refrigerant flowing through the first evaporator and the refrigerant flowing through the second condenser; and a blower that supplies air to the first condenser and the intercooler. At least a part of one condenser and the intermediate cooler are configured by an integrated heat exchanger in which heat transfer fins are integrated.

According to the refrigeration apparatus of the present invention, it is possible to easily balance the heat exchange amount (air volume) of the condenser of the high-temperature side refrigeration circuit and the heat exchange amount (air volume) of the intercooler of the low-temperature side refrigerant circuit. it can.
In addition, the manufacturing cost can be reduced.

It is a refrigerant circuit figure which shows roughly the refrigerant circuit structure of the refrigeration apparatus which concerns on Embodiment 1 of this invention. It is an internal perspective view which shows roughly the internal structure of the outdoor unit which concerns on Embodiment 1 of this invention. It is a perspective view which shows roughly the structure of the outdoor unit which concerns on Embodiment 1 of this invention. It is a top view which shows roughly the structure of the outdoor unit which concerns on Embodiment 1 of this invention. It is a figure which shows schematically the structure of the high temperature side condenser and intermediate cooler which concern on Embodiment 1 of this invention. It is a figure which shows the calculation result of the rated COP of the refrigeration apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the external temperature in a use area, and annual accumulation time. It is a figure which shows the calculation result of the annual power consumption of the freezing apparatus which concerns on Embodiment 1 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following drawings, the size relationship of each component may be different from the actual one.

Embodiment 1 FIG.
[Constitution]
FIG. 1 is a refrigerant circuit diagram schematically showing a refrigerant circuit configuration of a refrigeration apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the refrigeration apparatus 100 includes a high temperature side refrigerant circuit A and a low temperature side refrigerant circuit (load side circuit) B.
The high temperature side refrigerant circuit A and the low temperature side refrigerant circuit B are cascade-connected via a cascade capacitor 13.
The refrigeration apparatus 100 performs a dual refrigeration cycle by circulating refrigerant in each of the high temperature side refrigerant circuit A and the low temperature side refrigerant circuit B.

Here, in the configuration referred to as the low temperature side and the high temperature side, the level of temperature, pressure, etc. is not particularly determined in relation to absolute values, but in the state, operation, etc. of the refrigeration apparatus 100. It shall be relatively determined.
In the first embodiment, a two-stage refrigeration cycle including two refrigerant circuits will be described. However, the refrigeration apparatus according to the present invention includes three or more refrigeration cycles (multi-source refrigeration apparatus). Is included.

(High temperature side refrigerant circuit A)
The high temperature side refrigerant circuit A includes a high temperature side compressor 1, a high temperature side condenser 2, a high temperature side expansion valve 3, and a high temperature side evaporator 4.
The high temperature side compressor 1, the high temperature side condenser 2, the high temperature side expansion valve 3, and the high temperature side evaporator 4 are connected in series by a high temperature side refrigerant pipe 51.

In the high temperature side refrigerant circuit A, a liquid pipe side (high temperature) service valve 5 is provided in the liquid piping portion on the outlet side of the high temperature side condenser 2.
In the high temperature side refrigerant circuit A, a suction side (high temperature) service valve 6 is provided on the suction side of the high temperature side compressor 1.

As the refrigerant circulating through the high temperature side refrigerant circuit A, for example, an HFC (hydrofluorocarbon) refrigerant, an HFO (hydrofluoroolefin) refrigerant, an HC (hydrocarbon) refrigerant, or the like is used.
Examples of the HFC refrigerant include R410A, R404A, R32, R407C, and the like.

The high temperature side compressor 1 sucks the refrigerant flowing through the high temperature side refrigerant circuit A.
The high temperature side compressor 1 compresses the sucked refrigerant and discharges it in a high temperature and high pressure state.
The high temperature side condenser 2 performs heat exchange between the refrigerant discharged from the high temperature side compressor 1 and the air.
The high temperature side condenser 2 is comprised by the fin tube type heat exchanger which has a heat exchanger tube and many radiation fins, for example.

The high temperature side expansion valve 3 decompresses and expands the refrigerant that has flowed out of the high temperature side condenser 2.
The high temperature side evaporator 4 performs heat exchange between the refrigerant decompressed by the high temperature side expansion valve 3 and the refrigerant flowing through the low temperature side condenser 9 of the low temperature side refrigerant circuit B.
The high temperature side evaporator 4 and the low temperature side condenser 9 constitute a cascade condenser 13.
The cascade condenser 13 is composed of, for example, a plate type heat exchanger.
The cascade condenser 13 is not limited to a plate heat exchanger, and may be a shell-and-tube heat exchanger, a double tube heat exchanger, or the like.

The liquid pipe side service valve 5 is installed on the outlet side of the high temperature side condenser 2 and on the upstream side of the high temperature side expansion valve 3.
The liquid pipe side service valve 5 is used to perform operations such as evacuation of the high temperature side refrigerant circuit A and charging of the refrigerant into the high temperature side refrigerant circuit A.
The suction side service valve 6 is installed on the suction side of the high temperature side compressor 1 and on the downstream side of the high temperature side evaporator 4.
The suction side service valve 6 is used to perform operations such as evacuation of the high temperature side refrigerant circuit A and filling of refrigerant into the high temperature side refrigerant circuit A.

The high temperature side compressor 1, the high temperature side condenser 2, the high temperature side expansion valve 3, the high temperature side evaporator 4, the liquid pipe side service valve 5, and the suction side service valve 6 are accommodated in an outdoor unit 14. Yes.

The high temperature side compressor 1 corresponds to the “first compressor” in the present invention.
The high temperature side condenser 2 corresponds to a “first condenser” in the present invention.
The high temperature side expansion valve 3 corresponds to a “first throttle device” in the present invention.
The high temperature side evaporator 4 corresponds to the “first evaporator” in the present invention.

(Low temperature side refrigerant circuit B)
The low temperature side refrigerant circuit B includes a low temperature side compressor 7, an intermediate cooler 8, a low temperature side condenser 9, a liquid receiver 10, a low temperature side expansion valve 16, and a low temperature side evaporator 17.
The low temperature side compressor 7, the intermediate cooler 8, the low temperature side condenser 9, the liquid receiver 10, the low temperature side expansion valve 16, and the low temperature side evaporator 17 are connected in series by a low temperature side refrigerant pipe 52. Piping is connected.

In the low temperature side refrigerant circuit B, a liquid pipe side (low temperature) service valve 11 is provided in the liquid piping portion on the outlet side of the liquid receiver 10.
In the low temperature side refrigerant circuit B, a suction side (low temperature) service valve 12 is provided on the suction side of the low temperature side compressor 7.
A liquid pipe solenoid valve 15 is provided between the liquid pipe side service valve 11 and the low temperature side expansion valve 16.

As the refrigerant circulating through the low-temperature side refrigerant circuit B, for example, a carbon dioxide (CO ₂ ) refrigerant having a global warming potential (GWP) of 1 is used.
In addition, the refrigerant | coolant used for the low temperature side refrigerant circuit B is not limited to a carbon dioxide.

The low temperature side compressor 7 sucks the refrigerant flowing through the low temperature side refrigerant circuit B.
The low temperature side compressor 7 compresses the sucked refrigerant and discharges it in a high temperature and high pressure state.
The intercooler 8 performs heat exchange between the refrigerant discharged from the low temperature side compressor 7 and the air.
The intercooler 8 is constituted by, for example, a fin tube type heat exchanger having a heat transfer tube and a large number of radiating fins.
The low temperature side condenser 9 exchanges heat between the refrigerant that has flowed out of the intermediate cooler 8 and the refrigerant that flows through the high temperature side evaporator 4 of the high temperature side refrigerant circuit A.
The liquid receiver 10 stores excess refrigerant out of the refrigerant flowing out from the low-temperature side condenser 9.
The low temperature side expansion valve 16 decompresses and expands the refrigerant that has flowed out of the liquid receiver 10.
The low temperature side evaporator 17 performs heat exchange between the refrigerant decompressed by the low temperature side expansion valve 16 and a fluid (for example, air, water, a refrigerant, or brine).

The liquid pipe side service valve 11 is installed on the outlet side of the liquid receiver 10 and on the upstream side of the low temperature side expansion valve 16.
The liquid pipe side service valve 11 is used to perform operations such as evacuation of the low temperature side refrigerant circuit B and charging of the refrigerant into the low temperature side refrigerant circuit B.
The suction side service valve 12 is installed on the suction side of the low temperature side compressor 7 and on the downstream side of the low temperature side evaporator 17.
The suction side service valve 12 is used to perform operations such as evacuation of the low temperature side refrigerant circuit B and filling of the refrigerant into the low temperature side refrigerant circuit B.
The liquid pipe solenoid valve 15 is used to perform operations such as evacuation of the low temperature side refrigerant circuit B and filling of the refrigerant into the low temperature side refrigerant circuit B.

The low temperature side compressor 7, the intermediate cooler 8, the low temperature side condenser 9, the liquid receiver 10, the liquid pipe side service valve 11, and the suction side service valve 12 are accommodated in the outdoor unit 14.
The liquid pipe solenoid valve 15, the low temperature side expansion valve 16, and the low temperature side evaporator 17 are accommodated in the load side unit 18.

The low temperature side compressor 7 corresponds to the “second compressor” in the present invention.
The low temperature side condenser 9 corresponds to a “second condenser” in the present invention.
The low temperature side expansion valve 16 corresponds to a “second throttle device”.
The low temperature side evaporator 17 corresponds to a “second evaporator” in the present invention.

(Operation of high temperature side refrigerant circuit A)
The high-temperature and high-pressure gas-phase refrigerant discharged from the high-temperature side compressor 1 flows into the high-temperature side condenser 2.
The refrigerant flowing into the high temperature side condenser 2 is condensed and liquefied by heat exchange with air, and becomes a refrigerant in a liquid phase state at a high pressure.
The high-pressure and liquid-phase refrigerant that has flowed out of the high-temperature side condenser 2 is decompressed by the high-temperature-side expansion valve 3, and becomes a low-temperature and low-pressure refrigerant in the gas-liquid two-phase state.
This low-temperature low-pressure refrigerant in the gas-liquid two-phase state evaporates by exchanging heat with the refrigerant flowing through the low-temperature side condenser 9 of the low-temperature side refrigerant circuit B in the high-temperature side evaporator 4 constituting the cascade condenser 13. It becomes a gas-phase refrigerant at low pressure.
At this time, the refrigerant flowing through the low temperature side condenser 9 of the low temperature side refrigerant circuit B is cooled.
The refrigerant flowing out from the high temperature side evaporator 4 is sucked into the high temperature side compressor 1 again.

(Operation of low temperature side refrigerant circuit B)
The high-temperature and high-pressure gas-phase refrigerant discharged from the low-temperature side compressor 7 flows into the intercooler 8.
In the intercooler 8, the refrigerant in the gas phase at high temperature and high pressure exchanges heat with the air, and the refrigerant is cooled and the temperature is slightly lowered.
The refrigerant cooled by the intermediate cooler 8 flows into the low temperature side condenser 9 constituting the cascade condenser 13.
This low-temperature low-pressure refrigerant in the gas-liquid two-phase state evaporates by exchanging heat with the refrigerant flowing through the low-temperature side condenser 9 of the low-temperature side refrigerant circuit B in the high-temperature side evaporator 4 constituting the cascade condenser 13. It becomes a gas-phase refrigerant at low pressure.
The refrigerant flowing into the low temperature side condenser 9 is condensed by exchanging heat with the refrigerant flowing through the high temperature side evaporator 4 of the high temperature side refrigerant circuit A, and becomes a low temperature and high pressure liquid phase refrigerant.
At this time, the refrigerant flowing through the high temperature side evaporator 4 of the high temperature side refrigerant circuit A is heated.

The low-temperature and high-pressure liquid-phase refrigerant that has flowed out of the low-temperature side condenser 9 flows into the liquid receiver 10.
A part of the refrigerant that has flowed into the liquid receiver 10 is stored as surplus refrigerant, and the remainder flows into the low temperature side expansion valve 16.
The high-pressure and liquid-phase refrigerant that has flowed into the low-temperature side expansion valve 16 is decompressed and becomes a gas-liquid two-phase refrigerant.
The low-temperature and low-pressure gas-liquid two-phase refrigerant flows into the low-temperature evaporator 17.
In the low temperature side evaporator 17, the refrigerant evaporates by exchanging heat with a fluid (here, air), and becomes a high temperature and low pressure gas phase refrigerant.
At this time, the space to be cooled is cooled in the load side unit 18.
The low-pressure gas-phase refrigerant that has flowed out of the low-temperature side evaporator 17 is sucked into the low-temperature side compressor 7 again.

In the first embodiment, the state in which the liquid receiver 10 is connected as one of the components of the low temperature side refrigerant circuit B has been described as an example. However, the present invention is not limited to this, and the liquid receiver 10 is not necessarily limited thereto. Need not be connected.
Further, a liquid receiver such as an accumulator may be connected to the suction side of the low temperature side compressor 7 instead of the liquid receiver 10.
In other words, the liquid receiver may determine the presence / absence of connection and the selection of the type depending on the application of the refrigeration apparatus 100 and the refrigerant used.

Next, the arrangement of devices in each unit and details of the devices will be described.

(Load side unit 18)
The load side unit 18 accommodates a liquid pipe solenoid valve 15, a low temperature side expansion valve 16, and a low temperature side evaporator 17.
The load side unit 18 is used as, for example, a refrigerated freezer showcase or a unit cooler.
The load side unit 18 is pipe-connected so as to be separable from the outdoor unit 14 via the liquid pipe side service valve 11 and the suction side service valve 12.
For example, when installing the refrigeration apparatus 100, the outdoor unit 14 and the load-side unit 18 are transported separately and connected by piping on site.

(Outdoor unit 14)
FIG. 2 is an internal perspective view schematically showing the internal configuration of the outdoor unit according to Embodiment 1 of the present invention.
FIG. 3 is a perspective view schematically showing the configuration of the outdoor unit according to Embodiment 1 of the present invention.
FIG. 4 is a plan view schematically showing the configuration of the outdoor unit according to Embodiment 1 of the present invention.
As shown in FIGS. 2 to 4, the outdoor unit 14 includes a high temperature side housing 19 and a low temperature side housing 20.
The high temperature side casing 19 and the low temperature side casing 20 are configured by casings having the same outer shape.
The high temperature side casing 19 and the low temperature side casing 20 share a bottom plate with a common base 21.
The high temperature side casing 19 and the low temperature side casing 20 are installed adjacent to each other on the common mount 21.
The high temperature side housing 19 has a high temperature side outlet 30 on the upper surface.
The low temperature side housing | casing 20 has the low temperature side blower outlet 31 on the upper surface.
The high temperature side housing 19 has a high temperature side suction port 32 on a side surface.
The low temperature side housing 20 has a low temperature side suction port 33 on a side surface.

The high temperature side casing 19 includes a high temperature side compressor 1, a part of the high temperature side condenser 2, a high temperature side expansion valve 3, a liquid pipe side service valve 5, a suction side service valve 6, a high temperature side blower 22, and a high temperature side. A side controller 24 is installed.
The other part of the high temperature side condenser 2 is installed in the low temperature side housing 20.

The high temperature side condenser 2 installed in the high temperature side housing 19 is installed along the high temperature side suction port 32.
The high temperature side condenser 2 installed in the high temperature side housing 19 has a U-shaped cross section, for example.

The high temperature side blower 22 is installed on the upper portion of the high temperature side casing 19 and supplies air to the high temperature side condenser 2.
The high temperature side blower 22 is arranged on the upper side compared to the high temperature side condenser 2, sucks air from the high temperature side suction port 32, and passes the air that has passed through the high temperature side condenser 2 to the high temperature side outlet 19 of the high temperature side casing 19. Blow out from 30.

The high temperature side controller 24 executes various controls of the high temperature side equipment.
A high temperature side controller operation switch 25 is provided around or inside the high temperature side controller 24.
The high temperature side controller operation switch 25 receives an instruction to the high temperature side controller 24.

The liquid pipe side service valve 5 and the suction side service valve 6 are preferably arranged in the vicinity of the right side wall of the high temperature side casing 19 (in the vicinity of the side wall away from the low temperature side casing 20).
By installing the liquid pipe side service valve 5 and the suction side service valve 6 at this position, it contributes to the improvement of workability and maintainability.
That is, an operator who performs the installation of the outdoor unit 14 (for example, new installation or model exchange) and an operator who performs maintenance of the outdoor unit 14 (periodic maintenance, failure diagnosis, etc.) enclose the wrong refrigerant. The possibility of being lost can be reduced.
In addition, it is good to arrange | position the sight glass (not shown) or dryer (not shown) for local piping connection in the high temperature side housing | casing 19. FIG.

The low temperature side housing 20 includes a low temperature side compressor 7, another part of the high temperature side condenser 2, an intermediate cooler 8, a liquid receiver 10, a liquid pipe side service valve 11, a suction side service valve 12, a cascade condenser. 13. A low temperature side blower 23 and a low temperature side controller 26 are installed.

The high temperature side condenser 2 and the intermediate cooler 8 installed in the low temperature side housing 20 are configured as an integrated heat exchanger.
The intermediate cooler 8 is disposed in the low temperature side housing 20 at a position closer to the low temperature side blower 23 than the high temperature side condenser 2.
The high temperature side condenser 2 and the intermediate cooler 8 installed in the low temperature side housing 20 are installed along the low temperature side suction port 33.
The high temperature side condenser 2 and the intermediate cooler 8 installed in the low temperature side housing 20 have, for example, a U-shaped cross section.

The low temperature side blower 23 is installed in the upper part of the low temperature side housing 20 and supplies air to the high temperature side condenser 2.
The low temperature side blower 23 is disposed on the upper side compared to the intermediate cooler 8, sucks air from the low temperature side suction port 33, and passes through the high temperature side condenser 2 and the intermediate cooler 8 installed in the low temperature side housing 20. The blown air is blown out from the low temperature side air outlet 31 of the low temperature side housing 20.

The low temperature side controller 26 executes various controls of the low temperature side equipment.
A low temperature side controller operation switch 27 is provided around or inside the low temperature side controller 26.
The low temperature side controller operation switch 27 receives an instruction to the low temperature side controller 26.

The liquid pipe side service valve 11 and the suction side service valve 12 are desirably arranged in the vicinity of the left side wall of the low temperature side housing 20 (near the side wall on the side away from the high temperature side housing 19).
By installing the liquid pipe side service valve 11 and the suction side service valve 12 at this position, it contributes to the improvement of workability and maintainability.
That is, an operator who performs the installation (for example, new installation or model exchange) of the outdoor unit 14 and an operator who performs maintenance (periodic maintenance or failure diagnosis) of the outdoor unit 14 enclose the wrong refrigerant. Can be reduced.
In addition, it is good to arrange | position the sight glass (not shown) or dryer (not shown) for local piping connection in the low temperature side housing | casing 20. FIG.

Note that the cascade capacitor 13 extending over both the high temperature side and the low temperature side may be arranged in either the high temperature side casing 19 or the low temperature side casing 20 in consideration of the arrangement condition or the like.

The high temperature side casing 19 corresponds to the “high temperature side casing 19” in the present invention.
The low temperature side casing 20 corresponds to the “low temperature side casing 20” in the present invention.
The high temperature side blower 22 and the low temperature side blower 23 correspond to the “blower” in the present invention.
The high temperature side blower 22 corresponds to the “high temperature side blower 22” in the present invention.
The low temperature side blower 23 corresponds to a “second blower” in the present invention.

Here, the ratio of the processing capacity of the high temperature side condenser 2 of the high temperature side refrigerant circuit A and the processing capacity of the intermediate cooler 8 of the low temperature side refrigerant circuit B is about 7: 3.
Therefore, a part of the high temperature side condenser 2 is also installed in the low temperature side housing 20 in accordance with the ratio between the processing capacity of the high temperature side condenser 2 and the processing capacity of the intermediate cooler 8.

FIG. 5 is a diagram schematically showing the configuration of the high-temperature side condenser and the intercooler according to Embodiment 1 of the present invention.
As shown in FIG. 5, the heat exchanger constituting the high temperature side condenser 2 and the intermediate cooler 8 includes heat transfer fins 41 and heat transfer tubes 42.
The heat transfer fins 41 have, for example, a plate shape, are stacked at a predetermined interval, and air flows between them.
The heat transfer tube 42 is provided so as to penetrate the heat transfer fins 41, and the refrigerant circulates therein.
A plurality of heat transfer tubes 42 are arranged in the row direction (the horizontal direction on the paper surface) and in the step direction (the vertical direction on the paper surface).
In addition, the number of stages and the number of rows of the heat transfer tubes 42 illustrated in FIG. 5 are merely examples, and the present invention is not limited thereto.

A part of the intermediate cooler 8 and the high temperature side condenser 2 installed in the low temperature side housing 20 is constituted by an integrated heat exchanger in which the heat transfer fins 41 are integrated.

The high temperature side condenser 2 installed in the high temperature side housing 19 flows in the column direction after the refrigerant flows in from the inlet pipe 51a and branches in the step direction, and then flows in the row direction sequentially.
Then, the refrigerant that has flowed out of the high temperature side condenser 2 installed in the high temperature side casing 19 flows into the high temperature side condenser 2 installed in the low temperature side casing 20 via the relay pipe 51b.
The refrigerant that has flowed into the high-temperature side condenser 2 installed in the low-temperature side casing 20 branches in the stage direction, then turns back at the end side of the heat transfer tube 42, sequentially flows in the row direction, and flows out from the outlet pipe 51c. .
The distribution direction is not limited to this. The refrigerant may flow from the high temperature side condenser 2 installed in the low temperature side housing 20 to the high temperature side condenser 2 installed in the high temperature side housing 19.

The intercooler 8 installed in the low-temperature side casing 20 flows in from the inlet pipe 52a, branches in the step direction, then turns back at the end side of the heat transfer pipe 42, and sequentially flows in the column direction. It flows out of 52b.

In this way, the number of stages of the heat exchanger that constitutes the intermediate cooler 8 is adjusted, and a part of the heat exchanger functions as the high-temperature side condenser 2.
Further, the heat exchanger is divided into upper and lower parts so that the upper part functions as an intermediate cooler 8 and the lower part functions as a part of the high-temperature side condenser 2.
That is, the intermediate cooler 8 is disposed in the low temperature side housing 20 at a position closer to the low temperature side blower 23 than the high temperature side condenser 2.

Since the intermediate cooler 8 has a smaller number of stages than the high temperature side condenser 2, the processing capacity (heat exchange capacity) of the intermediate cooler 8 and the high temperature side condenser 2 is changed when the amount of air supplied is changed. The ratio is greatly affected.
The amount of air supplied into the low temperature side housing 20 becomes smaller as the distance from the low temperature side blower 23 increases as the equipment in the housing becomes an obstacle to the air flow.
The air volume supplied into the low temperature side casing 20 is turbulent due to obstacles such as equipment in the casing, and the air volume changes as the distance from the low temperature side blower 23 increases.
By disposing the intermediate cooler 8 at a position close to the low temperature side blower 23, it is possible to reduce the change in the air volume to the intermediate cooler 8.
Thereby, the balance between the heat exchange amount of the high temperature side condenser 2 and the heat exchange amount of the intermediate cooler 8 can be stabilized.
Moreover, the air volume to the intercooler 8 increases, and the heat exchange amount increases.
That is, the size (number of stages) of the intermediate cooler 8 can be reduced.

Here, it is desirable that the air volume supplied from the high temperature side blower 22 into the high temperature side casing 19 is the same as the air volume supplied from the low temperature side blower 23 into the low temperature side casing 20.
For example, by using the same type of blower for the high temperature side blower 22 and the low temperature side blower 23 and controlling the rotation speed to be the same, the air volume is made the same.
Thereby, the heat exchange amount of a part of the high temperature side condenser 2 installed in the high temperature side casing 19, the other part of the high temperature side condenser 2 installed in the low temperature side casing 20, and the intermediate cooler 8. The balance with the amount of heat exchange can be stabilized.
In addition, by using the same type of blower for the high temperature side blower 22 and the low temperature side blower 23, it is not necessary to install a blower having different power in each casing, leading to cost reduction.

Further, the number of stages of refrigerant pipes of the heat exchanger that constitutes a part of the high temperature side condenser 2 disposed in the high temperature side casing 19, and other than the high temperature side condenser 2 disposed in the low temperature side casing 20. It is desirable that the number of refrigerant pipes of the heat exchanger constituting the intermediate cooler 8 and the number of refrigerant pipes be the same.
Thereby, the ratio of the heat exchange amount can be accurately adjusted by the ratio between the number of stages of the high temperature side condenser 2 and the number of stages of the intermediate cooler 8 installed in the low temperature side casing 20.

As described above, in the present embodiment, a part of the high temperature side condenser 2 and the intermediate cooler 8 are configured as an integrated heat exchanger in which the heat transfer fins 41 are integrated.
For this reason, the positional relationship between a part of the high temperature side condenser 2 and the intercooler 8 with respect to the low temperature side blower 23 can be ensured with high accuracy. Therefore, the balance of the heat exchange amount (air volume) can be stabilized. Further, the manufacturing cost can be reduced by adopting the integrated type.

Further, the intermediate cooler 8 is disposed in the outdoor unit 14 at a position closer to the low temperature side blower 23 than the high temperature side condenser 2.
For this reason, the air volume of the air passing through the intercooler 8 is increased, and the amount of heat exchange is increased.
Therefore, the size of the intermediate cooler 8 for ensuring the heat exchange amount necessary for the intermediate cooler 8 can be reduced.
Moreover, since the intermediate cooler 8 can be made small, the space of the high temperature side condenser 2 can be enlarged.
That is, the refrigerating capacity with respect to the size of the device is improved.

Here, the ratio of the number of stages of the heat exchanger constituting the high temperature side condenser 2 and the number of stages of the heat exchanger constituting the intermediate cooler 8 will be described.
Under the following conditions, the number of stages for improving the COP at the rated outside air temperature and the number of stages for reducing the power consumption (annual power consumption) in one year will be described.
For example, the number of stages of the high temperature side condenser 2 arranged in the high temperature side casing 19 is 60, and the total number of stages of the high temperature side condenser 2 and the intermediate cooler 8 arranged in the low temperature side casing 20 is 60. And
The number of rows of the high temperature side condenser 2 and the intermediate cooler 8 is three.
Moreover, the air volume of the high temperature side fan 22 and the air volume of the low temperature side fan 23 are made the same.
Moreover, the outdoor unit 14 is installed outdoors, and the load side unit 18 is installed in a refrigerated warehouse.
The outside air temperature is 7 to 40 ° C as a parameter, and the inside temperature of the refrigerated warehouse is 0 ° C.
The rated outside air temperature is 32 ° C., and the rated capacity is 25 kW at this rated outside air temperature.
Then, the air volume of each blower is controlled so that the condensation temperature of the high-temperature side condenser 2 becomes the outside air temperature + 10 ° C.
It is assumed that the input power to the blower changes in proportion to the air volume of the blower.

FIG. 6 shows the result of calculating the COP for the following conditions under the above conditions.
When there is no intercooler 8 and the number of stages of the high-temperature side condenser 2 is 120.
When the number of stages of the intercooler 8 is 4, and the number of stages of the high-temperature side condenser 2 is 116.
When the number of stages of the intermediate cooler 8 is 10 and the number of stages of the high-temperature side condenser 2 is 110.
When the number of stages of the intermediate cooler 8 is 20 and the number of stages of the high-temperature side condenser 2 is 100.
When the number of stages of the intermediate cooler 8 is 30, and the number of stages of the high-temperature side condenser 2 is 90.
When the number of stages of the intermediate cooler 8 is 60 and the number of stages of the high-temperature side condenser 2 is 60.
As shown in FIG. 6, when the number of stages of the intermediate cooler 8 is 20, the COP is 1.88 and becomes the maximum. Further, when the number of stages of the intercooler 8 is 10 and 30, it is a relatively high value.

In addition to the above-mentioned conditions, the annual power consumption is calculated by calculating the power consumption at each outdoor temperature (input power to each compressor + input power to each blower) and calculating an approximate expression of the input power characteristics with respect to the outside air temperature. create.
Then, the annual accumulated time of the outside air temperature in the area assumed to be used is investigated, and the power consumption amount at each outside air temperature is calculated and summed to calculate the annual power consumption amount.
Here, as shown in FIG. 7, the annual cumulative time in Tokyo is used.
The results of calculating the annual power consumption are shown in FIG.
As shown in FIG. 8, when the number of stages of the intercooler 8 is 10, 20, and 30, the annual power consumption is reduced. The number of stages of the intermediate cooler 8 is minimum when the number of stages is 10.

From the above results, the COP at the rated outside air temperature is adjusted by adjusting the ratio of the number of stages of the intermediate cooler 8 and the high temperature side condenser 2 installed in the low temperature side housing 20 to 1: 5 to 3: 3. Can be improved, and the annual power consumption can be reduced.

1. High temperature side compressor, 2. High temperature side condenser, 3. High temperature side expansion valve, 4. High temperature side evaporator, 5. Liquid pipe side service valve, 6. Inlet side service valve, 7. Low temperature side compressor, 8. Intermediate cooler, 9. Low temperature. Side condenser, 10 liquid receiver, 11 liquid pipe side service valve, 12 suction side service valve, 13 cascade condenser, 14 outdoor unit, 15 liquid pipe solenoid valve, 16 low temperature side expansion valve, 17 low temperature side evaporator, 18 load Side unit, 19 high temperature side case, 20 low temperature side case, 21 common frame, 22 high temperature side blower, 23 low temperature side blower, 24 high temperature side control controller, 25 high temperature side control controller operation switch, 26 low temperature side control controller, 27 Low temperature side controller operation switch, 30 High temperature side outlet, 31 Low temperature side outlet, 32 High temperature side suction Port, 33 low temperature side suction port, 41 heat transfer fin, 42 heat transfer tube, 51 high temperature side refrigerant piping, 51a inlet piping, 51b relay piping, 51c outlet piping, 52 low temperature side refrigerant piping, 52a inlet piping, 52b outlet piping, 100 Refrigeration equipment, A high temperature side refrigerant circuit, B low temperature side refrigerant circuit.

Claims

A first refrigerant circuit in which a first compressor, a first condenser, a first throttling device, and a first evaporator are sequentially connected by piping and the refrigerant circulates;
A second refrigerant circuit in which a second compressor, an intercooler, a second condenser, a second expansion device, and a second evaporator are sequentially connected by piping, and the refrigerant circulates;
A cascade condenser composed of the first evaporator and the second condenser, wherein the refrigerant flowing through the first evaporator and the refrigerant flowing through the second condenser exchange heat;
A blower for supplying air to the first condenser and the intercooler,
At least a part of the first condenser and the intermediate cooler are constituted by an integrated heat exchanger in which heat transfer fins are integrated.
At least the first condenser, the intermediate cooler, and the blower are installed in an outdoor unit,
2. The refrigeration apparatus according to claim 1, wherein the intermediate cooler is arranged in a position closer to the blower than the first condenser in the outdoor unit.
The outdoor unit includes a first housing and a second housing,
A portion of the first condenser is disposed within the first housing;
The other part of the first condenser and the intercooler are constituted by an integrated heat exchanger in which heat transfer fins are integrated, and are arranged in the second casing.
The blower is
A first blower that is disposed in the first housing and supplies air into the first housing;
A second blower disposed in the second housing and supplying air into the second housing;
The refrigeration apparatus according to claim 2, wherein the air volume supplied into the first housing is the same as the air volume supplied into the second housing.
The number of stages of refrigerant piping of the heat exchanger constituting the first condenser disposed in the first housing;
The refrigerating apparatus according to claim 3, wherein the number of stages of refrigerant pipes of the heat exchanger constituting the first condenser and the intermediate cooler arranged in the second casing is the same.
The first housing has a first suction port on a side surface, a first air outlet on an upper surface,
The second housing has a second suction port on a side surface and a second air outlet on an upper surface,
A portion of the first condenser is disposed along the first suction port,
The other part of the first condenser and the intercooler are disposed along the second suction port,
The intermediate cooler is disposed on the upper side compared to the other part of the first condenser,
The first blower is disposed above the part of the first condenser, sucks air from the first suction port, and passes the air passing through the part of the first condenser to the first casing. Blowing out from the outlet of the body,
The second blower is disposed above the intermediate cooler, sucks air from the second suction port, and passes the other part of the first condenser and the air that has passed through the intermediate cooler to the air The refrigeration apparatus according to claim 3 or 4, wherein the refrigeration apparatus blows out from the second outlet.