CN107305070B

CN107305070B - Refrigeration device and method for operating refrigeration device

Info

Publication number: CN107305070B
Application number: CN201710196714.8A
Authority: CN
Inventors: 藤野博之; 增野谦
Original assignee: East Pre Co ltd
Current assignee: East Pre Co ltd
Priority date: 2016-04-22
Filing date: 2017-03-29
Publication date: 2020-10-27
Anticipated expiration: 2037-03-29
Also published as: TW201738515A; CN107305070A; TWI711795B; JP6706534B2; JP2017194245A

Abstract

The invention provides a refrigerating device which can well heat a cooled storage. In order to solve the above problem, the refrigeration apparatus of the present invention is provided with a refrigerant circuit (51R), and the refrigerant circuit (51R) includes an interior heat exchanger (5) and an exterior heat exchanger (3). The external heat exchanger (3) is provided with: a1 st external heat exchanger (3A) and a2 nd external heat exchanger (3B); a1 st piping path (L3) which connects the 1 st external heat exchanger (3A) and the 2 nd external heat exchanger (3B) and which allows only the flow from the 1 st external heat exchanger (3A) to the 2 nd external heat exchanger (3B); and a1 st decompressor (7) disposed in the 1 st piping path (L3); the refrigerant circuit (51R) further includes: a2 nd pipe path (L8, L9) connecting the inside heat exchanger (5) and the 1 st outside heat exchanger (3A); and a Bypass Path (BP) which connects the 2 nd piping path (L8, L9) and the 1 st pressure reducer (7) in the 1 st piping path (L3) and the 2 nd external heat exchanger (3B), and in which an on-off valve (61V) and the 2 nd pressure reducer (62) are disposed.

Description

Refrigeration device and method for operating refrigeration device

Technical Field

The present invention relates to a refrigeration apparatus and an operation method of the refrigeration apparatus, and more particularly, to a refrigeration apparatus capable of selectively performing a cooling operation and a heating operation, and an operation method of the refrigeration apparatus.

Background

Patent document 1 describes a known refrigerator car equipped with a refrigeration device that can not only cool the interior of the car but also raise the temperature of the car.

Since the refrigerator car can transport the goods (fresh goods and the like) stored in the storage at the optimum temperature without being affected by the outdoor air temperature, the refrigerator car can be used to deliver the goods to stores such as convenience stores, for example.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2015-163829

Disclosure of Invention

Problems to be solved by the invention

When the refrigerator car provided with the refrigeration apparatus described in patent document 1 is used to deliver the refrigerator car to stores such as convenience stores, the following delivery efficiency is expected to decrease in an environment where the outside air is high-temperature and high-humidity, such as in the summer heat in japan.

In the distribution work, a Tray (Tray) with goods (fresh goods and the like) is loaded into a pre-cooled storage of a refrigerator car at a distribution center, and the goods are distributed to stores in a suitable temperature state.

The goods are then delivered to the store, and the empty pallets are brought back to the distribution center. At this time, the inside of the warehouse is returned in a cooled state, and when the warehouse door is opened to load the next batch of goods, the high-temperature and high-humidity outside air flowing into the warehouse comes into contact with the cooled tray, and dew condensation may occur on the tray. If dew condensation occurs on the tray, the loading of the goods is troublesome, and the delivery efficiency is lowered.

Therefore, it is desired that the interior cooled by the cooling operation at the time of the delivery to the distribution center is subjected to the temperature raising operation in advance so as to reach a temperature at which dew condensation does not occur at the time of return, and thus distribution efficiency is not lowered by dew condensation on the tray even if the outside air is high in temperature and humidity.

That is, the refrigerating apparatus mounted on the refrigerator car is desired to be capable of quickly raising the temperature of the interior of the refrigerator after the interior has been sufficiently cooled.

However, in the refrigeration apparatus described in patent document 1, when the cooling operation mode is switched to the temperature increasing operation mode, the low-temperature and high-pressure liquid refrigerant cooled and condensed by the interior heat exchanger flows into the 1 st exterior heat exchanger functioning as the supercooling heat exchanger.

Here, when the outdoor air temperature is significantly high, such as in the afternoon of a summer season, at least the 1 st outdoor heat exchanger is heated by the outdoor air, and the temperature is much higher than usual.

Therefore, the liquid refrigerant flowing into the 1 st outdoor heat exchanger is likely to boil and vaporize, and may not sufficiently pass through the expansion valve of the downstream 2 nd outdoor heat exchanger.

If the refrigerant cannot pass through the expansion valve, it is expected that the amount of refrigerant circulating in the refrigerant circuit decreases, and the refrigerant enters a negative pressure operation state, resulting in a decrease in temperature raising capability.

That is, a good temperature rise may not be performed, and the above-described delivery efficiency may be lowered.

Accordingly, an object of the present invention is to provide a refrigeration apparatus capable of satisfactorily raising the temperature of a cooled compartment, and a method of operating the refrigeration apparatus.

Means for solving the problems

In order to solve the above problems, the present invention has the following configuration and order.

1) A refrigeration apparatus provided with a refrigerant circuit including an interior heat exchanger and an exterior heat exchanger, the refrigeration apparatus being capable of selectively performing a cooling operation for cooling a storage chamber in which the interior heat exchanger is disposed and a heating operation for heating the storage chamber,

the external heat exchanger includes:

a1 st external heat exchanger and a2 nd external heat exchanger; a1 st piping path which connects the 1 st external heat exchanger and the 2 nd external heat exchanger and allows only the flow from the 1 st external heat exchanger to the 2 nd external heat exchanger; and a1 st decompressor disposed on the 1 st piping path;

the refrigerant circuit further includes:

a2 nd piping path connecting the inside heat exchanger and the 1 st outside heat exchanger; and a process for the preparation of a coating,

and a bypass path connecting the 2 nd piping path, the 1 st decompressor and the 2 nd external heat exchanger in the 1 st piping path, and having an opening/closing valve and a2 nd decompressor disposed therein.

2) The refrigeration apparatus according to claim 1), further comprising:

a1 st temperature sensor for measuring a temperature of the refrigerant flowing through the 2 nd pipe path;

a2 nd temperature sensor for measuring a temperature of the refrigerant flowing between the 1 st external heat exchanger and the 1 st decompressor in the 1 st piping path; and a process for the preparation of a coating,

and a control unit for controlling the opening and closing operation of the opening and closing valve based on the 1 st temperature measured by the 1 st temperature sensor and the 2 nd temperature measured by the 2 nd temperature sensor.

3) A refrigeration apparatus provided with a refrigerant circuit including an interior heat exchanger and an exterior heat exchanger, the refrigeration apparatus being capable of selectively performing a cooling operation for cooling a storage chamber in which the interior heat exchanger is disposed and a heating operation for heating the storage chamber,

the heat exchanger in the storage includes a heat exchanger in the 1 st storage and a heat exchanger in the 2 nd storage;

the external heat exchanger includes: a1 st external heat exchanger and a2 nd external heat exchanger; a1 st piping path which connects the 1 st external heat exchanger and the 2 nd external heat exchanger and allows only the flow from the 1 st external heat exchanger to the 2 nd external heat exchanger; and a1 st decompressor disposed on the 1 st piping path;

the refrigerant circuit further includes:

a2 nd piping path having one end connected to the 1 st external heat exchanger and the other end branched at a branch portion to connect the 1 st internal heat exchanger and the 2 nd internal heat exchanger; and a process for the preparation of a coating,

and a bypass path connecting the branching portion in the 2 nd piping path and the 1 st outdoor heat exchanger, and connecting the 1 st decompressor and the 2 nd outdoor heat exchanger in the 1 st piping path, and including an on-off valve and a2 nd decompressor arranged therein.

4) The refrigeration apparatus according to claim 3), further comprising:

a1 st temperature sensor and a2 nd temperature sensor, the 1 st temperature sensor measuring a temperature of the refrigerant flowing between the 1 st interior heat exchanger and the branch portion in the 2 nd piping path, the 2 nd temperature sensor measuring a temperature of the refrigerant flowing between the 2 nd interior heat exchanger and the branch portion in the 2 nd piping path;

a3 rd temperature sensor for measuring a temperature of the refrigerant flowing between the 1 st external heat exchanger and the 1 st decompressor in the 1 st piping path; and a process for the preparation of a coating,

and a control unit for controlling the opening and closing operation of the opening and closing valve based on the 1 st to 3 rd temperatures measured by the 1 st to 3 rd temperature sensors, respectively.

5) The refrigeration apparatus according to claim 3), further comprising:

a1 st temperature sensor that measures a temperature of the refrigerant flowing between the branch portion of the 2 nd piping path and the 1 st interior heat exchanger;

and a control unit for controlling the opening and closing operation of the opening and closing valve based on the 1 st temperature and the 2 nd temperature measured by the 1 st temperature sensor and the 2 nd temperature sensor, respectively.

6) The refrigeration apparatus according to any one of claims 1) to 5), wherein the external heat exchanger includes a fin connected across the 1 st external heat exchanger and the 2 nd external heat exchanger.

7) The refrigeration apparatus according to any one of claims 1) to 6), wherein an amount of the refrigerant flowing through the 2 nd decompressor is larger than an amount of the refrigerant flowing through the 1 st decompressor.

8) A method of operating a refrigeration apparatus according to 2) or 5), the method comprising:

a1 st determination step of determining whether or not a value obtained by subtracting the 2 nd temperature from the 1 st temperature is lower than a positive specific value and a specific elapsed time elapses while the temperature raising operation is being executed;

a valve opening step of opening the on-off valve when it is determined that the determination step 1 has passed;

a2 nd determination step of determining whether or not a value obtained by subtracting the 2 nd temperature from the 1 st temperature is equal to or greater than the specific value after the valve opening step; and a process for the preparation of a coating,

a valve closing step of closing the on-off valve when it is determined that the opening/closing valve is in the closed state at the determination step 2.

9) A method of operating a refrigeration system according to 4), the method comprising:

a1 st determination step of determining whether or not at least one of a value obtained by subtracting the 3 rd temperature from the 1 st temperature and a value obtained by subtracting the 3 rd temperature from the 2 nd temperature is lower than a positive specific value and a specific elapsed time elapses while the temperature raising operation is being performed;

a2 nd determination step of determining whether or not both a value obtained by subtracting the 3 rd temperature from the 1 st temperature and a value obtained by subtracting the 3 rd temperature from the 2 nd temperature are equal to or greater than the specific value after the valve opening step; and a process for the preparation of a coating,

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the effect of making it possible to satisfactorily raise the temperature of the cooled interior can be obtained.

Drawings

Fig. 1 is a refrigerant circuit diagram for explaining a refrigerant circuit 51R of a refrigeration apparatus 51, which is example 1 of the refrigeration apparatus according to the embodiment of the present invention.

Fig. 2 is a block diagram for explaining the configuration of a control system of the freezing device 51.

Fig. 3 is a schematic diagram for explaining the structure of the exterior heat exchanger 3 disposed in the refrigerant circuit 51R.

Fig. 4 is a table for explaining the operation mode of the refrigerating apparatus 51.

Fig. 5 is a refrigerant circuit diagram for explaining the operation of the refrigerant circuit 51R in mode a.

Fig. 6 is a refrigerant circuit diagram for explaining the operation in mode B of the refrigerant circuit 51R.

Fig. 7 is a refrigerant circuit diagram for explaining the operation of the mode B2 of the refrigerant circuit 51R.

Fig. 8 is a schematic diagram for explaining a refrigerator car C on which the refrigerating apparatus 51 is mounted.

Fig. 9 is a table for explaining the operation contents of the refrigerant circuit 51R.

Fig. 10 is a graph for explaining the refrigerant temperature at the time of the negative pressure operation, the start of the bypass operation, and the end of the bypass operation of the refrigerant circuit 51R.

Fig. 11 is a flowchart for explaining a control procedure of the bypass operation in the refrigeration apparatus 51.

Fig. 12 is a refrigerant circuit diagram for explaining a refrigerant circuit 52R of the refrigeration apparatus 52 according to embodiment 2.

Fig. 13 is a block diagram for explaining the configuration of the control system of the freezing device 52.

Fig. 14 is a schematic diagram for explaining the structure of the exterior heat exchanger a3 disposed in the refrigerant circuit 52R.

Fig. 15 is a schematic diagram for explaining a refrigerator car AC on which a refrigerating apparatus 52 is mounted.

Fig. 16 is a table for explaining the operation mode of the refrigerating apparatus 52.

Fig. 17 is a diagram for explaining an operation mode of the four-way valve a2 disposed in the refrigerant circuit 52R.

Fig. 18 is a table for explaining the relationship between the storage room of the freezer vehicle AC and the type of the solenoid valve set.

Fig. 19 is a refrigerant circuit diagram for explaining the operation of pattern number 1.

Fig. 20 is a refrigerant circuit diagram for explaining the operation of pattern number 2.

Fig. 21 is a refrigerant circuit diagram for explaining the operation of pattern number 3.

Fig. 22 is a refrigerant circuit diagram for explaining the operation of pattern number 4.

Fig. 23 is a refrigerant circuit diagram for explaining the operations of the

mode numbers

5 and 6.

Fig. 24 is a refrigerant circuit diagram for explaining the operations of the

mode numbers

7 and 8.

Fig. 25 is a refrigerant circuit diagram for explaining the operation of the bypass operation.

Fig. 26 is a flowchart for explaining a control procedure of the bypass operation in the refrigeration apparatus 52.

Fig. 27 is a refrigerant circuit diagram for explaining a refrigerant circuit 151R of the refrigeration apparatus 151 of modification 1.

Fig. 28 is a refrigerant circuit diagram for explaining the operation of the cooling operation in the refrigerant circuit 151R.

Fig. 29 is a refrigerant circuit diagram for explaining an operation of the temperature increasing operation in the refrigerant circuit 151R.

Fig. 30 is a refrigerant circuit diagram for explaining the operation of the bypass operation in the refrigerant circuit 151R.

Fig. 31 is a diagram for explaining the bypass operation in the refrigeration apparatus 52.

Description of the symbols

1: compressor with a compressor housing having a plurality of compressor blades

2: four-way valve

2a to 2 d: port(s)

3: heat exchanger outside warehouse

3A: 1 st external heat exchanger

3Aa, 3 Ab: port(s)

3B: no. 2 external heat exchanger

3Ba, 3 Bb: port(s)

4: liquid receiver

5a, 5 b: port(s)

6: liquid storage device

7. 12: expansion valve

8-10, 14-16, 63: check valve

11. 13, 61V: electromagnetic valve

31: control unit

32: input unit

51. 52, 151: refrigerating device

51R, 52R, 151R: refrigerant circuit

62: thin tube

A: operating conditions under negative pressure

BP: bypass path

C: freezing vehicle

C1: library (storage)

CV: inner space

D1-D4, D61, D62: branching part

FM1, FM 2: fan (air-blower)

LP1, LP 2: parallel loop

L1-L11, 3LA, 3 LB: piping path

L61: bypass path

L62: this route

Na and Nb: number of passages

P1-P5: route of travel

RA, RB 2: flow passage

RK: flow direction regulating part

S: accommodating body

tm: elapsed time

TS1, TS 2: temperature sensor

t1, t 2: temperature of

α, α s, α 2: value of

Beta: time of day

A1: compressor with a compressor housing having a plurality of compressor blades

A2: a four-way valve,

A2 a-A2 d: (of four-way valve) port

A3: heat exchanger outside warehouse

A3A: 1 st external heat exchanger

A3Aa, A3 Ab: port(s)

A3B: no. 2 external heat exchanger

A3Ba, A3 Bb: port(s)

A4: liquid receiver

A5A, A5B: heat exchanger in warehouse

A5AU, A5 BU: heat exchanger unit in storehouse

A6: liquid storage device

A11-A13, A14A-A16A, A14B-A16B, A61V: electromagnetic valve

A11G: electromagnetic valve group

A21, a22A, a 22B: expansion valve

A31a, a31b, a32A, a32B, a33, a34, a 63: check valve

A31G: check valve group

A41: control unit

A42: input unit

A62: thin tube

ABP: bypass path

AC: freezing vehicle

ACH: vehicle body part

ACT: refrigerator

ACA, ACB: storehouse

ACVA, ACVB: inner space

AD1 to AD5, AD6A, AD6B, AD7, AD8, AD61, AD 62: branching part

AF1, AF2A, AF 2B: fan (air-blower)

AFG: fan set

ALP 1: parallel loop

AL1～AL3、AL4a、AL4b、AL5、AL6、AL7A、AL7B、AL8A、AL8B、AL9～AL12、AL12A、AL12B、AL13、

AL13A, AL13B, AL 14-AL 16: piping path

AP 1-AP 9: route of travel

AS: accommodating body

ATS1, ATS1a. ATS1b, ATS 2: temperature sensor

At1A, At1B, At 2: temperature of

Atm: elapsed time

LH 1-LH 7: 1 st to 7 th piping paths

LK: universal tubing

M1: source stream block

M2: external heat exchange block

M3: heat exchange block in storehouse

M3a, M3b, M3 c: block port

RK 1: flow channel switching part

R1-R3: refrigerant flow channel

TK: intermediate path

Detailed Description

A refrigeration apparatus according to an embodiment of the present invention will be described with reference to fig. 1 to 31, using the refrigeration apparatus 51 of example 1, the refrigeration apparatus 52 of example 2, and the like.

< example 1>

The structure of the refrigerating apparatus 51 is shown in a refrigerant circuit diagram, that is, fig. 1, and a control system diagram, that is, fig. 2.

That is, the refrigerant circuit 51R of the refrigeration apparatus 51 has the following structure: a compressor 1, a four-way valve 2, an outside heat exchanger 3 (including a motor-driven blower, i.e., a fan FM1), a liquid receiver 4, an inside heat exchanger 5 (including a motor-driven blower, i.e., a fan FM2), a liquid reservoir (accumulator)6, a solenoid valve 11, and a solenoid valve 13.

The operations of the compressor 1, the four-way valve 2, the fan FM1, the fan FM2, the solenoid valve 11, and the solenoid valve 13 in the refrigerant circuit are controlled by the controller 31.

The operation instruction from the user is transmitted to the control unit 31 via the input unit 32.

The outside-house heat exchanger 3 and the inside-house heat exchanger 5 are so-called fin and tube type heat exchangers. The outdoor heat exchanger 3 has the following structure: the 1 st-compartment external heat exchanger 3A and the 2 nd-compartment external heat exchanger 3B, and a circuit (parallel circuit LP1) connecting the 1 st-compartment external heat exchanger 3A and the 2 nd-compartment external heat exchanger 3B in series on the refrigerant circuit.

Fig. 3 is a diagram for explaining the structure of the outdoor heat exchanger 3.

The 1 st outdoor heat exchanger 3A has a refrigerant piping path 3LA connecting the port 3Aa and the port 3 Ab. The 2 nd outdoor heat exchanger 3B has a refrigerant piping path 3LB connecting the port 3Ba and the port 3 Bb.

The 1 st bank-outside heat exchanger 3A has the path P1 and the path P2 as two paths in parallel.

The 2 nd outdoor heat exchanger 3B has paths P3 to P5 as three paths connected in parallel.

Thus, the number Na of passages in the 1 st bank-exterior heat exchanger 3A is an integer of 2 or more and is equal to or less than the number Nb (an integer of Nb: 2 or more) of passages in the 2 nd bank-exterior heat exchanger. That is, 2. ltoreq. Na. ltoreq. Nb.

The path P1 and the path P2 of the outdoor heat exchanger 3A are arranged as follows: the regions do not overlap each other with respect to the air blowing direction (the left-right direction of the paper surface in fig. 3), and are substantially independent on the suction surface.

Similarly, in the outdoor heat exchanger 3B, the passages P3 to P5 are arranged as follows: substantially do not overlap each other with respect to the air blowing direction, and are substantially independent areas on the suction surface.

The 1 st outdoor heat exchanger 3A and the 2 nd outdoor heat exchanger 3B are arranged in parallel in the flow direction of the wind generated by driving the fan FM 1.

In detail, the 1 st external heat exchanger 3A is configured in the following manner: the air flow direction generated by the driving of fan FM1 is on the windward side.

That is, the 1 st external heat exchanger 3A is an upstream side heat exchanger, and the 2 nd external heat exchanger 3B is a downstream side heat exchanger.

The refrigerant circuit 51R of the refrigeration apparatus 51 will be described in detail.

The compressor 1 and the port 2a of the four-way valve 2 are connected by a pipe path L1.

The port 2B of the four-way valve 2 and the port 3Ba of the 2 nd outdoor heat exchanger 3B of the outdoor heat exchangers 3 are connected by a pipe path L2.

The port 3Bb of the 2 nd external heat exchanger 3B and the port 3Ab of the 1 st external heat exchanger 3A are connected via a parallel circuit LP 1.

The parallel circuit LP1 has a structure in which the pipe path L3 and the pipe path L4 are connected in parallel.

The piping path L3 includes: an expansion valve 7; and a check valve 8 connected in series to the 1 st outdoor heat exchanger 3A side with respect to the expansion valve 7 and allowing flow only from the 1 st outdoor heat exchanger 3A to the 2 nd outdoor heat exchanger 3B.

A check valve 9 is disposed in the pipe path L4, and the check valve 9 allows only the flow from the 2 nd external heat exchanger 3B to the 1 st external heat exchanger 3A.

The parallel circuit LP1 is provided with a branch portion D62, and the branch portion D62 is provided between the port 3Bb of the 2 nd external heat exchanger and the pipe paths L3 and L4.

A temperature sensor TS2 is disposed in the parallel circuit LP1, and the temperature sensor TS2 measures the temperature of the refrigerant flowing through the section between the port 3Ab of the 1 st outdoor heat exchanger 3A and the pipe path L3 and the pipe path L4.

Preferably, the temperature sensor TS2 is disposed at a position close to the port 3 Ab.

The port 3Aa of the 1 st external heat exchanger 3A and the liquid receiver 4 are connected by a pipe path L5.

A branch portion D1 and a branch portion D2 are provided midway in the pipe path L5. A check valve 10 is disposed between the branch portion D1 and the branch portion D2, and the check valve 10 allows only the flow from the 1 st external heat exchanger 3A to the liquid receiver 4.

The liquid receiver 4 is connected to the port 5b of the in-tank heat exchanger 5 via a parallel circuit LP 2. The parallel circuit LP2 has a structure in which the pipe path L6 and the pipe path L7 are connected in parallel.

The piping path L6 includes: an electromagnetic valve 11; and an expansion valve 12 connected in series to the electromagnetic valve 11 on the side of the interior heat exchanger 5.

The solenoid valve 13 is disposed on the pipe path L7.

The port 5a of the interior heat exchanger 5 and the port 2d of the four-way valve 2 are connected by a pipe path L8. A branch portion D3 and a branch portion D4 are provided midway in the pipe path L8. A check valve 14 is disposed between the branch portion D3 and the branch portion D4, and the check valve 14 allows only the flow from the interior heat exchanger 5 to the four-way valve 2.

A temperature sensor TS1 is disposed on the pipe path L8, and the temperature sensor TS1 measures the temperature of the refrigerant flowing through the section between the interior heat exchanger 5 and the branch portion D3.

Preferably, the temperature sensor TS1 is disposed at a position close to the port 5a of the in-house heat exchanger 5.

The branch portion D3 of the pipe path L8 and the branch portion D1 of the pipe path L5 are connected by a pipe path L9. A check valve 15 is disposed on the pipe path L9, and the check valve 15 allows only the flow from the branch portion D3 to the branch portion D1.

The pipe path L9 is provided with a branch portion D61, and the branch portion D61 is provided between the port 3Aa of the 1 st external heat exchanger 3A and the branch portion D1.

The branch portion D61 and the branch portion D62 of the parallel circuit LP1 are connected by a pipe path L61. Hereinafter, the pipe path L61 is also referred to as a bypass L61.

The bypass L61 is provided with: an electromagnetic valve 61V as an opening/closing valve, a capillary tube (capillary tube)62, and a check valve 63 for allowing a flow from the branch portion D61 to the branch portion D62.

The opening and closing operations of the solenoid valve 61V are controlled by the control unit 31 (see fig. 2).

The capillary tube 62 is hereinafter referred to as a capillary tube 62.

The narrow tube 62 functions as a pressure reducer in the same manner as the expansion valve 7. The narrow tube 62 is used as a decompressor, and the amount of refrigerant passing therethrough is larger than that of the expansion valve 7.

The branch portion D4 of the pipe path L8 and the branch portion D2 of the pipe path L5 are connected by a pipe path L10. A check valve 16 is disposed on the pipe path L10, and the check valve 16 allows only the flow from the branch portion D4 to the branch portion D2.

The four branch portions and the four check valves, i.e., the branch portions D1 to D4, the check valve 10, and the check valves 14 to 16, constitute a flow direction regulating portion RK.

The flow direction restriction unit RK restricts the flow direction of the refrigerant flowing in and out from the port 3Aa of the exterior heat exchanger 3 by selecting a flow path by switching the four-way valve 2. The details are as follows.

The port 2c of the four-way valve 2 is connected to the compressor 1 via the accumulator 6 and the pipe path L11.

In this refrigerant circuit 51R, the control unit 31 selectively controls the four-way valve 2 and the

solenoid valves

11, 13, and 61V so as to set them to any one of the mode a, the mode B, and the mode B2.

Fig. 4 is a diagram for explaining an operation mode controlled by the control unit 31.

Mode a is the following operating mode: in the four-way valve 2, the port 2a and the port 2b are connected to each other, and the port 2c and the port 2d are connected to each other, and the

solenoid valves

13 and 61V are closed and the solenoid valve 11 is opened.

Mode B is the following operation mode: in the four-way valve 2, the port 2a and the port 2d are connected to each other, the port 2b and the port 2c are connected to each other, the solenoid valve 13 is opened, and the

solenoid valves

11 and 61V are closed.

Mode B2 is the following operational mode: with respect to pattern B, the solenoid valve 61V is opened.

The modes A, B and B2 are explained with reference to fig. 5 to 7, respectively. Fig. 5 to 7 show the piping paths through which the refrigerant flows in the refrigerant circuit 51R shown in fig. 1 as thick lines, and the directions of the flows are indicated by arrows.

In the mode a, the four-way valve 2 defines a flow passage RA (see the thick line path in fig. 5) through which the refrigerant flows.

In the mode B, B2, the path through which the refrigerant flows is the flow path RB (see the thick line path in fig. 6).

That is, the four-way valve 2 functions as a flow path selector, and the path through which the refrigerant flows in the refrigerant circuit is selectively set to either the flow path RA or the flow path RB.

As shown in fig. 4, the control unit 31 performs the opening and closing operations of the solenoid valve 11, the solenoid valve 13, and the solenoid valve 61V as the opening and closing valves in conjunction with the operation of the four-way valve 2.

In the mode B2, the solenoid valve 61V that is closed in the mode B is opened.

Thus, the path through which the refrigerant flows in the mode B2 is a path in which the flow path RB2 of the bypass L61 is added to the flow path RB.

In detail, in the mode B2, a part of the flow channel RB in the mode B is connected in parallel with the flow channel RB 2.

The detailed operation of modes A, B and B2 is described below.

The refrigerating apparatus 51 having the above configuration can be applied to various apparatuses and devices. For example, the vehicle is loaded on a refrigerator car C.

Fig. 8 is a side view showing a loading example of the refrigerator car C with a cut surface in part.

The interior heat exchanger 5 is disposed in an interior space CV of a storage container (container) C1 (hereinafter, simply referred to as a storage container C1) that is a container to be kept at a constant temperature in the refrigerator car C, and exchanges heat with air in the interior space CV.

The outdoor heat exchanger 3 is disposed outside the storage container C1 (for example, above the driver's seat), and exchanges heat with the outside air.

The other members are disposed outside the storage C1, and the disposition position is not limited.

For example, the compressor 1, the accumulator 6, and the like are housed in the housing S and provided in the lower portion of the vehicle body. The control unit 31 and the input unit 32 are provided near the driver's seat. In particular, the input unit 32 is disposed in a place where the driver can easily operate.

The power source of the compressor 1 is, for example, a battery or an engine (both not shown) of the refrigerator car C.

Next, the operation of the refrigeration apparatus 51 will be described mainly with reference to fig. 5 to 7 and 9, based on the state of being mounted on the refrigeration vehicle C.

The refrigeration apparatus 51 selectively operates in a plurality of operation modes (modes A, B and B2) so that the temperature in the bank C1 is constant, based on an instruction from the user via the input unit 32.

Mode a is a cooling operation mode.

Mode B is a temperature increasing operation mode. The defrosting operation of the interior heat exchanger 5 is also performed in the mode B.

Mode B2 is a bypass mode of operation. The bypass operation mode is the following mode: when the operation in the temperature increasing operation mode (hereinafter simply referred to as temperature increasing operation) is performed after the operation in the cooling operation mode (hereinafter simply referred to as cooling operation), the operation is performed according to the determination of the control unit 31 in some cases. The operation in the bypass operation mode is simply referred to as bypass operation.

First, the cooling operation and the temperature increasing operation will be described. Here, the basic operation contents under the general environmental conditions (the conditions where the outside air is not extremely high temperature) in which the negative pressure operation is not performed are described.

Fig. 5 is a diagram for explaining a refrigerant circuit in the cooling operation. Fig. 6 is a diagram for explaining a refrigerant circuit during the temperature raising operation. Fig. 7 is a diagram for explaining the refrigerant circuit in the bypass operation. Fig. 9 is a table for explaining the control of the control unit 31 in each operation. In fig. 5 to 7, piping portions in the refrigerant circuit 51R where the refrigerant flows are indicated by thick lines, and the flow direction of the refrigerant is indicated by thick arrows.

(Cooling operation: mode A)

As shown in fig. 9, in the mode a cooling operation, the control unit 31 sets the four-way valve 2 to the mode a, sets the solenoid valve 11 to the open state, sets the solenoid valve 13 and the solenoid valve 61V to the closed state, and sets the fans FM1 and FM2 to the operating state.

The blowing directions of the fan FM1 and the fan FM2 during this cooling operation are indicated by arrows DR1 and DR2, respectively, in fig. 5.

As shown in fig. 5, the high-pressure gaseous refrigerant discharged from the discharge port of the compressor 1 is controlled by the control unit 31 to flow from the port 2a of the four-way valve 2 in the mode a into the pipe path L2 through the port 2 b.

The gas refrigerant flowing into the pipe path L2 is supplied from the port 3Ba to the 2 nd outdoor heat exchanger 3B of the outdoor heat exchangers 3, flows through any one of the passages P3 to P5, and then flows out from the port 3Bb as a gas-liquid mixed refrigerant.

The gas-liquid mixed refrigerant flowing out of the port 3Bb flows into the pipe path L4 without flowing into the bypass L61 because the solenoid valve 61V is closed.

The flow-through check valve 9 is supplied from the port 3Ab to the 1 st outdoor heat exchanger 3A, flows through any one of the passages P1 and P2, and flows out from the port 3 Aa.

In the outdoor heat exchanger 3, the fan FM1 is controlled by the control unit 31 to be in an operating state, and outside air flows in the direction of arrow DR1 in fig. 5.

In this state, of the external heat exchangers 3, the 2 nd external heat exchanger 3B and the 1 st external heat exchanger 3A function as a condenser integrally.

That is, the gaseous refrigerant radiates heat to the outside air and condenses, and flows as a high-pressure liquid refrigerant from the port 3Aa into the pipe passage L5.

Specifically, the refrigerant is entirely in a gas phase at the inlet of the 2 nd outdoor heat exchanger 3B, that is, at the port 3 Ba. The gas-phase refrigerant exchanges heat with the outside air as it flows through the 2 nd outdoor heat exchanger 3B, and a part of the gas-phase refrigerant is condensed (liquefied), so that the ratio of the liquid-phase refrigerant to the gaseous-phase refrigerant increases.

Accordingly, most of the refrigerant becomes a gas-liquid mixed refrigerant of the liquid refrigerant at the outlet of the 2 nd outdoor heat exchanger 3B, that is, at the port 3 Bb. Here, the ratio of the liquid refrigerant differs depending on the operating conditions.

Subsequently, the gas-liquid mixed refrigerant flowing out of the port 3Bb flows into the 1 st outdoor heat exchanger 3A from the port 3 Ab. The heat exchange between the refrigerant and the outside air is continued by the 1 st outdoor heat exchanger 3A, and substantially all of the refrigerant becomes a liquid phase under high pressure at the outlet, that is, the port 3 Aa.

The refrigerant changes its phase from a gas phase to a liquid phase in the exterior heat exchanger 3, thereby reducing the volume of the refrigerant.

In the bank-exterior heat exchanger 3, the number Na of passages of the 1 st bank-exterior heat exchanger 3A through which the refrigerant having a high liquid phase ratio flows due to a reduction in volume is smaller than the number Nb of passages of the 2 nd bank-exterior heat exchanger 3B through which the refrigerant having a high gas phase ratio flows. Thus, the refrigerant flowing through the 1 st outdoor heat exchanger 3A has a higher flow velocity and a higher degree of supercooling than the refrigerant flowing through the 2 nd outdoor heat exchanger 3B as a liquid refrigerant.

The high-pressure liquid refrigerant flowing into the pipe line L5 passes through the check valve 10 and enters the liquid receiver 4.

In the liquid receiver 4, the remaining amount of the liquid refrigerant corresponding to the operating environment is retained.

For example, when the heat load in the tank C1 is small, the amount of the circulating refrigerant may be small, and a large amount of the liquid refrigerant may be accumulated in the liquid receiver 4. On the other hand, when the heat load in the tank C1 is large, the amount of the liquid refrigerant accumulated in the liquid receiver 4 becomes small because a large amount of the circulating refrigerant is required.

The liquid receiver 4 has the following structure: when liquid refrigerant accumulates, the liquid refrigerant flows out.

The liquid refrigerant flowing out of the liquid receiver 4 flows into the pipe path L6 under the control of the control unit 31, because the solenoid valve 13 is closed and the solenoid valve 11 is opened.

That is, the liquid refrigerant flowing into the pipe line L6 passes through the solenoid valve 11 and enters the expansion valve 12.

In the expansion valve 12, the liquid refrigerant expands. As a result, the liquid refrigerant is reduced in pressure and temperature, and vaporization is promoted, so that the liquid refrigerant becomes a gas-liquid mixed refrigerant in which a gas phase and a liquid phase are mixed.

The gas-liquid mixed refrigerant flowing out of the expansion valve 12 flows into the interior heat exchanger 5.

In the indoor heat exchanger 5, the fan FM2 is controlled by the controller 31 to be in an operating state, and the air in the cabin C1 flows in the direction of arrow DR2 in fig. 5.

In this state, the gas-liquid mixed refrigerant exchanges heat with the air in the bank C1, obtains heat from the air in the bank C1, and is completely vaporized to become a gaseous refrigerant.

That is, the in-bank heat exchanger 5 functions as an evaporator to cool the interior of the bank C1.

The gas refrigerant flowing out of the interior heat exchanger 5 flows into the pipe passage L8.

In the pipe path L8, the pressure at the branch portion D3 of the gaseous refrigerant is lower than the pressure at the branch portion D1 of the pipe path L5, and therefore, the gaseous refrigerant does not flow into the pipe path L9, but passes through the check valve 14 to reach the four-way valve 2.

Since the four-way valve 2 is controlled by the controller 31 to be in the mode a, the gaseous refrigerant flows from the port 2d to the port 2c, further flows through the accumulator 6, and returns to the suction port of the compressor 1.

(temperature-increasing operation: mode B)

As shown in fig. 6, during the temperature increasing operation, the control unit 31 sets the four-way valve 2 to the mode B, closes the

solenoid valves

11 and 61V, opens the solenoid valve 13, and sets the fans FM1 and FM2 to the operating state.

The blowing directions of the fans FM1 and FM2 during the temperature raising operation are the same as those in the cooling operation and are indicated by arrows DR3 and DR4 in fig. 6, respectively.

As shown in fig. 6, the control unit 31 controls the high-pressure gaseous refrigerant discharged from the discharge port of the compressor 1 to flow into the pipe passage L8 through the port 2d of the four-way valve 2 in the mode B. Then, the gaseous refrigerant flows into the pipe path L10 from the branch portion D4, and enters the liquid receiver 4.

In the liquid receiver 4, the liquid refrigerant accumulated in the previous cooling operation is pushed out by the gaseous refrigerant, and the liquid receiver 4 is quickly filled with the gaseous refrigerant.

Therefore, the gaseous refrigerant flows out of the liquid receiver 4 after following the liquid refrigerant in the receiver portion. Since the electromagnetic valve 13 is opened and the electromagnetic valve 11 is closed under the control of the control unit 31, the gaseous refrigerant flowing out of the liquid receiver 4 flows into the pipe path L7 and then flows into the interior heat exchanger 5.

In the indoor heat exchanger 5, as described above, the fan FM2 is controlled by the control unit 31 to be in an operating state, and the air in the cabin C1 flows in the direction of arrow DR4 in fig. 6.

In this state, the gas refrigerant exchanges heat with the air in the bank C1, releases heat to the air in the bank C1, condenses, and becomes a substantially high-pressure liquid refrigerant. Therefore, the temperature in the bank C1 is increased.

The refrigerant flowing out of the interior heat exchanger 5 contains a liquid refrigerant and a gaseous refrigerant in an amount corresponding to an operating environment such as a heat load in the interior C1.

Since the pressure at the branch portion D3 is lower than that at the branch portion D4, the gas-liquid mixed refrigerant including the liquid refrigerant and the gas refrigerant flows into the pipe path L9.

After passing through the check valve 15, the solenoid valve 61V is closed at the branch portion D61, and therefore, the entire flow does not flow into the bypass L61, but flows into the 1 st external heat exchanger 3A of the external heat exchangers 3 from the port 3 Aa.

In the outdoor heat exchanger 3, the fan FM1 is controlled by the control unit 31 to be in an operating state, and outside air flows in the direction of arrow DR3 in fig. 6. Therefore, the 1 st outdoor heat exchanger 3A is located on the upstream side of the 2 nd outdoor heat exchanger 3B through which the outside air flows.

In this state, the liquid refrigerant is cooled in the 1 st outdoor heat exchanger 3A, and the temperature thereof is lowered.

That is, the 1 st outdoor heat exchanger 3A functions as a supercooling heat exchanger for the liquid refrigerant.

The gaseous refrigerant flowing into the 1 st outdoor heat exchanger 3A together with the liquid refrigerant is cooled by the gaseous refrigerant, and substantially all of the gaseous refrigerant becomes the liquid refrigerant.

The supercooled liquid refrigerant flows out from the port 3Ab of the 1 st outdoor heat exchanger 3A and flows into the pipe path L3.

In the pipe line L3, the liquid refrigerant passes through the check valve 8 and enters the expansion valve 7.

In the expansion valve 7, the liquid refrigerant expands. As a result, the liquid refrigerant is reduced in pressure and temperature, and vaporization is promoted, so that the liquid refrigerant becomes a gas-liquid mixed refrigerant in which a gas phase and a liquid phase are mixed.

The gas-liquid mixed refrigerant flowing out of the expansion valve 7 flows into the 2 nd outdoor heat exchanger 3B from the port 3 Bb.

In the 2 nd outdoor heat exchanger 3B, the gas-liquid mixed refrigerant flowing from the port 3Bb obtains heat from the outside air by heat exchange with the outside air, evaporates, turns into a gaseous refrigerant, and flows into the pipe passage L2 from the port 3 Ba.

That is, the 2 nd external heat exchanger 3B functions as an evaporator.

The gaseous refrigerant flowing into the pipe path L2 passes through the port 2B of the four-way valve 2 in the mode B, the port 2c, the accumulator 6, and returns to the suction port of the compressor 1.

In this temperature raising operation, the refrigerating apparatus 51 obtains the following effects.

Switching between the cooling operation and the temperature-raising operation is performed using the four-way valve, and in the temperature-raising operation, the temperature is raised not only by the heat obtained by the operation of the compressor but also by the heat obtained from the outside air by the external heat exchanger. Therefore, a higher temperature raising capability is obtained.

The switching between the cooling operation and the temperature increasing operation is basically performed only by switching between the four-way valve and the solenoid valve, and is not required to be controlled based on the measurement result of the pressure sensor or the like. Therefore, the control of the operation is simple.

In the 2 nd outdoor heat exchanger 3B, the gas-liquid mixed refrigerant undergoes heat exchange for taking out heat from the outside air, and becomes a low-pressure gaseous refrigerant.

In the out-of-bank heat exchanger 3, a plurality of fins (fin, not shown) are provided so as to straddle the 1 st out-of-bank heat exchanger 3A and the 2 nd out-of-bank heat exchanger 3B and are shared. Therefore, in the 1 st external heat exchanger 3A, part of the heat released from the liquid refrigerant is transferred to the 2 nd external heat exchanger 3B by the fins, and is utilized as evaporation heat of phase change in the 2 nd external heat exchanger 3B.

Accordingly, since the evaporation of the liquid refrigerant in the 2 nd outdoor heat exchanger 3B is promoted, it is possible to prevent the so-called liquid slugging phenomenon, in which the liquid refrigerant is sucked into the compressor.

In this temperature raising operation, no liquid refrigerant remains in the liquid receiver 4. On the other hand, the refrigerant circulation amount required for the refrigerant circuit 51R changes depending on the operating environment including the heat load in the bank C1.

Therefore, the liquid refrigerant and the gaseous refrigerant in an amount corresponding to the operating environment exist in the 1 st outdoor heat exchanger 3A of the refrigeration apparatus 51.

In other words, the 1 st outdoor heat exchanger 3A adjusts and secures the remaining liquid refrigerant in place of the liquid receiver 4 during the temperature raising operation so that the refrigerant circuit 51R circulates the refrigerant in an amount most suitable for the operating environment.

This can maintain the pressure on the high-pressure side of the refrigerant circuit 51R at a high value.

Therefore, the refrigerant condensation temperature in the interior heat exchanger 5 becomes high, and the temperature raising capability is improved.

The refrigeration apparatus 51 makes the direction of the refrigerant flowing through the interior heat exchanger 5 the same during the cooling operation and the temperature increasing operation by using the flow direction regulating portion RK or the like. The direction of the airflow generated by the operation of fan FM2 is also the same in the cooling operation and the temperature increasing operation.

(defrosting operation of the interior heat exchanger 5: mode B)

If the cooling operation is performed for a long time, moisture contained in the air in the bank C1 may freeze and frost and adhere to the fins of the in-bank heat exchanger 5. Since frost formation on the fins hinders heat exchange, the defrosting operation of the in-bank heat exchanger 5 is performed to defrost.

As shown in fig. 9, this defrosting operation differs from the temperature raising operation only in stopping the fan FM 2.

(bypass operation: mode B2)

For example, under general environmental conditions other than the heat season in japan, the refrigeration apparatus 51 may perform the temperature raising operation after the cooling operation so that the temperature in the refrigerator that has been cooled to a low temperature immediately rises.

On the other hand, as described above, when the outside air is extremely high in temperature, and when the temperature raising operation is performed directly after the cooling operation, the low-temperature and low-boiling-point liquid refrigerant condensed by the in-house heat exchanger 5 which has been cooled to a low temperature may boil and evaporate when the refrigerant flows into the 1 st out-house heat exchanger 3A which has been warmed to a high temperature by the outside air.

In the graph of fig. 10, the temperature of each part in the flow path RB in this state is shown as an example in the negative pressure operation (temperature indicated by a black circle).

The temperature t1 of the refrigerant flowing out of the port 5a of the interior heat exchanger 5 measured by the temperature sensor TS1 is a low temperature significantly lower than 0 ℃. On the other hand, the temperature of the refrigerant warmed by the 1 st outdoor heat exchanger 3A and flowing out of the port 3Ab measured by the temperature sensor TS2 is t2, which is a high temperature significantly higher than 0 ℃ (t1 < t 2).

Since the refrigerant vaporized by boiling evaporation cannot sufficiently pass through the expansion valve 7 of the piping path L3, the amount of refrigerant circulating through the flow passage RB of the refrigerant circuit 51R decreases, and a negative pressure operation state is achieved, and the temperature raising capability is lowered.

In the refrigeration apparatus 51, the bypass operation is performed as a preventive measure for preventing the negative pressure operation state from occurring and when the cooling operation is switched to the temperature increasing operation.

Specifically, the control unit 31 determines whether or not the bypass operation is executed in the sequence example described later, and controls switching between the bypass operation and the temperature increasing operation.

First, the circulation and operation of the refrigerant when the bypass operation is performed under an environmental condition (hereinafter, referred to as a negative pressure operation transition condition a) in which the negative pressure operation state can be established will be described.

The basic operation of the bypass operation is the same as the temperature raising operation. Therefore, the flow of the refrigerant different from the temperature raising operation will be mainly described here.

First, as shown in fig. 4 and 9, the bypass operation is performed by turning the solenoid valve 61V from the closed state to the open state during the temperature increasing operation.

Since the air in the interior has reached a low temperature during the cooling operation, the refrigerant becomes substantially a liquid refrigerant by heat exchange in the interior heat exchanger 5 and flows out to the pipe path L8.

When the electromagnetic valve 61V is opened, the low-temperature high-pressure liquid refrigerant flowing out of the interior heat exchanger 5 is branched at the branch portion D61 in the pipe path L9, as shown in fig. 7.

Specifically, the refrigerant flow is divided into: the flow flowing into the 1 st outdoor heat exchanger 3A from the port 3Aa (hereinafter referred to as the main flow) and the flow generated only during the bypass operation, that is, the flow flowing through the bypass L61 (hereinafter referred to as the bypass flow).

The liquid refrigerant flowing into the 1 st outdoor heat exchanger 3A as the main flow is heated by the outside air to become a high temperature in the 1 st outdoor heat exchanger 3A, and thus the temperature is raised.

Under the negative pressure operation condition a, the temperature of the 1 st external heat exchanger 3A warmed by the outside air is higher than the boiling point of the inflowing liquid refrigerant.

Therefore, the liquid refrigerant is heated by the 1 st outdoor heat exchanger 3A, boiled and evaporated to become a gaseous refrigerant, and flows into the expansion valve 7.

Here, since the gaseous refrigerant cannot sufficiently pass through the expansion valve 7, the refrigerant from the main flow substantially does not flow through the piping path after the expansion valve 7 or flows only in a small amount.

On the other hand, the liquid refrigerant flowing into the bypass L61 as a bypass flow is decompressed by the narrow tube 62, passes through the check valve 63, flows through the branch portion D62, and flows into the 2 nd external heat exchanger 3B from the port 3 Bb.

The liquid refrigerant from the bypass flow flowing into the 2 nd outdoor heat exchanger 3B is evaporated by heat exchange with the outside air. Since this heat exchange is also performed between the liquid refrigerant and the 2 nd bank external heat exchanger 3B itself, the 2 nd bank external heat exchanger 3B is cooled.

The temperature of each portion in the flow path RB in this state shown in the graph of fig. 10 is an example of the temperature at the start of the bypass operation (temperature indicated by a hollow square).

The temperature of the refrigerant flowing out of the port 5a of the interior heat exchanger 5 measured by the temperature sensor TS1 is t 1'. On the other hand, the temperature of the refrigerant flowing out of the port 3Ab of the 1 st outdoor heat exchanger 3A measured by the temperature sensor TS2 is t2 ', or the temperature of the refrigerant flowing out of the port 3Ab is higher (t1 ' < t2 ').

As the 2 nd bank outside heat exchanger 3B cools, the temperature of the 1 st bank outside heat exchanger 3A sharing the fins also decreases.

The temperature of the 1 st outdoor heat exchanger 3A is lowered, and the boiling evaporation of the main stream flowing into the 1 st outdoor heat exchanger 3A is thereby stopped at an initial stage.

Therefore, the amount of the liquid refrigerant flowing out of the 1 st outdoor heat exchanger 3A, that is, the amount of the refrigerant passing through the expansion valve 7, is increased rapidly.

Therefore, the amount of refrigerant circulating through the refrigerant circuit 51R is not drastically reduced, and the refrigerant is quickly recovered even if the amount is reduced.

In this way, the refrigeration apparatus 51 has the bypass path BP (see fig. 1) composed of the bypass L61 including the electromagnetic valve 61V, the narrow tube 62, and the check valve 63, and thereby can perform the bypass operation.

In the bypass operation, the refrigerant can be supplied to the 2 nd exterior heat exchanger 3B by opening the solenoid valve 61V and generating a bypass flow through the bypass L61.

Therefore, the amount of refrigerant circulating in the refrigerant circuit 51R is not drastically reduced, but is secured to a certain amount or more, and the negative pressure operation is difficult to occur. Even if the negative pressure operation is generated, the temperature is initially returned to the normal temperature increasing operation.

The temperatures of the respective portions in the flow path RB at the time of completion of the bypass operation shown in the graph of fig. 10 are examples according to the time of completion of the bypass operation (temperatures indicated by black diamonds).

The temperature of the refrigerant flowing out of the port 5a of the interior heat exchanger 5 measured by the temperature sensor TS1 is t1 ". On the other hand, the temperature of the refrigerant flowing out of the port 3Ab of the 1 st outdoor heat exchanger 3A measured by the temperature sensor TS2 is t2 ″ and lower than t1 ″. Thus, the temperature of the refrigerant flowing out of the port 5a of the interior heat exchanger 5 and the temperature of the refrigerant flowing out of the port 5a of the interior heat exchanger 5 are reversed from the start of the bypass operation. (t1 '> t 2')

In this example, since the difference in the reverse rotation temperatures (t1 "-t 2") is equal to or greater than the predetermined value α (deg), the bypass operation is terminated by the control unit 31, such as by releasing the negative pressure operation. The specific value α and the determination sequence will be described next.

A method of determining whether or not the bypass operation is performed during the temperature increase operation after the cooling operation will be described. The determination is made by the control unit 31 based on the temperatures t1 and t2 obtained by the temperature sensors TS1 and TS 2.

The temperature sensor TS1 measures the temperature t1 (see fig. 2) of the refrigerant flowing out of the interior heat exchanger 5, and sends the measurement result to the controller 31.

The temperature sensor TS2 measures the temperature t2 (see fig. 2) of the refrigerant flowing out of the 1 st outdoor heat exchanger 3A, and sends the measurement result to the controller 31.

The control unit 31 controls the operation of the bypass operation according to the sequence example shown in fig. 11 (flowchart).

First, the control unit 31 executes the cooling operation in response to an external instruction (S1).

Next, the control unit 31 switches from the cooling operation to the temperature increasing operation in response to an external instruction (S2). Thereby, the temperature increasing operation is started.

The control section 31 determines whether or not the following values are less than a specific value α (S3), that is: the value of the detected temperature of the temperature sensor TS2, that is, the temperature t2 is subtracted from the detected temperature from the temperature sensor TS1, that is, the temperature t1 (t1-t 2).

This determination is preferably performed at short time intervals, more preferably in real time and continuously.

The value α is a value set as appropriate in accordance with the specification of the refrigeration apparatus 51, the operating environment of the refrigerator car C, and the like, and is, for example, 5 (deg).

The value α may be set to either a negative value or a positive value. The lower limit is about-3 (deg) under the usual specification.

Therefore, in order to establish (S3) when the value α is set to a negative number, it is at least t1-t2< 0.

Similarly, when the value α is set to 0 (zero), it is at least t1-t2 ≦ 0.

And, when the value α is a positive number, it may be any one of t1-t2<0, t1-t2> 0.

If the determination at S3 is "No" (No), the control unit 31 determines whether or not an operation stop instruction is given from the outside (S8), and if No, continues the determination (S3).

When the determination at (S8) is Yes (Yes), the temperature raising operation is stopped (S9), and the operation is ended.

When the determination of (S3) is Yes, it is determined whether or not the elapsed time tm after the determination of Yes is equal to or longer than a specific time β seconds (S4).

The specific time β is set as appropriate in accordance with the operating characteristics of the refrigerating apparatus 51 and the like. For example 20 seconds.

If the determination at (S4) is No, the routine proceeds to (S8), and if there is No stop instruction, the routine proceeds to (S3).

If the determination at (S3) is Yes, the elapsed time tm is accumulated.

When the determination of (S4) is Yes, the control unit 31 determines that the bypass operation is to be performed, and opens the electromagnetic valve 61V (S5).

The temperature distribution in the flow path RB that meets this determination is shown at the start of the bypass operation and at the time of the negative pressure operation in fig. 10.

Specifically, at the time of starting the bypass operation, the value α s obtained by subtracting the temperature t2 from the temperature t1 is less than the value α, and at the time of the negative pressure operation, the value α s obtained by subtracting the temperature t2 from the temperature t1 is significantly less than the value α, so the control unit 31 determines the execution of the bypass operation.

During the execution of the bypass operation, the control unit 31 determines whether or not the following values are equal to or greater than a specific value α: the value α S of the detected temperature of the temperature sensor TS2, that is, the temperature t2 is subtracted from the detected temperature from the temperature sensor TS1, that is, the temperature t1 (S6).

When the determination of (S6) is No, the control unit 31 continues (S6) the determination.

When the determination at (S6) is Yes, the possibility that the negative pressure operation is cancelled or changed to the negative pressure operation is very small, and the control unit 31 stops the bypass operation and returns to the normal temperature increasing operation. That is, the electromagnetic valve 61V is closed (S7).

The controller 31 executes (S7) and moves back to (S8).

Thus, after the cooling operation is shifted to the temperature increasing operation, the controller 31 compares the temperature t1 of the refrigerant flowing out of the interior heat exchanger 5 with the temperature t2 of the refrigerant flowing out of the 1 st exterior heat exchanger 3A. If the value α s obtained by subtracting the temperature t2 from the temperature t1 is less than the predetermined value α and the state continues for the predetermined elapsed time tm or longer, it is determined that there is a high possibility that the negative pressure operation is generated or will be generated, and the bypass operation is executed.

During the execution of the bypass operation, the temperatures t1 and t2 are monitored, and when the value α s based on the two temperatures is equal to or greater than the specific value α, the bypass operation is shifted to the normal temperature increasing operation.

The bypass operation is performed when the cooling operation is switched to the temperature increasing operation, and is also performed appropriately in accordance with the temperatures t1 and t2 during the temperature increasing operation.

Therefore, even if the external environment changes with time and the negative pressure operation condition a is restored, the occurrence of the negative pressure operation can be prevented.

This makes it possible to increase the temperature of the refrigerated interior in a short time and satisfactorily in the refrigeration apparatus 51 and the refrigeration vehicle C provided with the refrigeration apparatus 51.

< example 2>

The refrigeration apparatus 52 will be described as example 2. The refrigeration apparatus 52 is an example (two in this example) including a plurality of in-compartment heat exchangers, as compared with the refrigeration apparatus 51 of example 1.

The structure of the refrigeration apparatus 52 is shown in fig. 12, which is a diagram of the refrigerant circuit 52R, and fig. 13, which is a diagram of the control system.

First, a schematic structure of the refrigerating apparatus 52 will be described.

The refrigeration device 52 includes a heat pump type refrigerant circuit 52R.

The refrigerant circuit 52R has the following structure: a compressor A1, a four-way valve A2, an off-bay heat exchanger A3 including a fan AF1, an accumulator a4, an in-bay heat exchanger A5A including a fan AF2A, an in-bay heat exchanger A5B including a fan AF2B, an accumulator A6, a solenoid valve group a11G including a plurality of solenoid valves (see fig. 13: details as described below), expansion valves a21, a22A, a22B, and a check valve group a31G including a plurality of check valves (not shown: details as described below).

Fans AF1, AF2A, and AF2B are blowers driven by motors, and they are collectively referred to as a fan group AFG (see fig. 13).

The solenoid valve group a11G is a general term for collective solenoid valves a11, a12, a13, a14A, a14B, a15A, a15B, a16A, and a 16B.

The check valve group a31G is a generic name of the collective check valves a31a, a31b, a32A, a32B, a33, and a 34.

As shown in fig. 13, the refrigeration apparatus 52 includes a control unit a 41. The operation instruction by the user is transmitted to the control unit a41 via the input unit a 42. And a controller a41 that controls the operations of the compressor A1, the four-way valve a2, the fan group AFG, and the solenoid valve group a11G in the refrigerant circuit 52R based on the transmitted instructions and the like.

The outside heat exchanger a3, the inside heat exchanger A5A, and the inside heat exchanger A5B have a so-called finned tube structure.

The offsite heat exchanger A3 includes a1 st offsite heat exchanger A3A and a2 nd offsite heat exchanger A3B. Details of the ex-house heat exchanger a3 are described below.

Next, the refrigerant circuit 52R is described in detail.

In order to make fig. 12 easy to understand, the refrigerant circuit 52R is described as divided into the following three blocks: source flow block M1, comprising compressor a1, four-way valve a2, and reservoir a 6; an off-bank heat exchange block M2, comprising an off-bank heat exchanger A3 and a parallel loop ALP 1; and an in-house heat exchange block M3 including a liquid receiver a4, an in-house heat exchanger A5A, and an in-house heat exchanger A5B.

At the lower right in fig. 12, the compressor a1 is connected to the port A2a of the four-way valve A2 by a pipe path AL 1.

The port A2b of the four-way valve A2 and the port A3Ba of the 2 nd outdoor heat exchanger A3B in the outdoor heat exchanger A3 are connected by a pipe path AL 2.

Port A3Bb of bank 2 external heat exchanger A3B is connected to port A3Ab of bank 1 external heat exchanger A3A via a parallel circuit ALP1 as described above.

One end side of the parallel circuit ALP1 is connected to the port A3Bb through a pipe path AL3, and the other end side is connected to the port A3Ab through a pipe path AL 5. The solenoid valve a11 is disposed in the pipe path AL 5.

The parallel circuit ALP1 has a parallel pipe line AL4a and a parallel pipe line AL4 b.

The pipe path AL4a includes: expansion valve a 21; and a check valve a31a connected in series to the 1 st outdoor heat exchanger A3A side with respect to the expansion valve a21 and allowing flow only from the 1 st outdoor heat exchanger A3A to the 2 nd outdoor heat exchanger A3B.

A check valve a31b is disposed in the pipe path AL4b, and the check valve a31b allows only the flow from the 2 nd outdoor heat exchanger A3B to the 1 st outdoor heat exchanger A3A.

A branch portion AD1 is provided between the solenoid valve a11 and the port A3Ab in the pipe path AL 5.

One end side of the pipe path AL6 is connected to the branch portion AD 1. The other end of the pipe path AL6 is connected to the branch section AD2 through the block port M3a of the indoor heat exchange block M3. The solenoid valve a12 is disposed in the pipe path AL 6.

The branch portion AD2 is connected to the port A5Aa of the interior heat exchanger A5A by a pipe path AL 7A. The solenoid valve a14A and the expansion valve a22A are arranged in series on the pipe path AL7A from the branch portion AD2 side.

The branch portion AD2 is connected to the port A5Ba of the interior heat exchanger A5B by a pipe path AL 7B. The solenoid valve a14B and the expansion valve a22B are arranged in series on the pipe path AL7B from the branch portion AD2 side.

One end side of the pipe path AL8A is connected to the port A5Ab of the in-warehouse heat exchanger A5A. A branch portion AD3 is provided on the other end side of the pipe path AL 8A. The solenoid valve a15A is disposed in the pipe path AL 8A.

One end side of the pipe path AL8B is connected to the port A5Bb of the in-warehouse heat exchanger A5B. A branching portion AD3 is connected to the other side of the pipe path AL 8B. The solenoid valve a15B is disposed in the pipe path AL 8B.

The branch section AD3 and the port A2c of the four-way valve A2 are connected by the pipe path AL9 via the block port M3c of the interior heat exchange block M3.

In the upper left portion of fig. 12, one end side of a pipe path AL10 on which a solenoid valve a13 is disposed is connected to the branch portion AD 2. A branch portion AD4 is provided on the other end side of the pipe path AL 10.

The branch portion AD4 and the port A3Aa of the 1 st outdoor heat exchanger A3A are connected by the pipe path AL11 through the block port M3b of the indoor heat exchange block M3.

The liquid receiver a4 and the branch portion AD5 are disposed on the pipe path AL11 from the branch portion AD4 side. One end side of the pipe path AL12 branched from the pipe path AL11 is connected to the branch portion AD 5.

A branch portion AD55 is provided on the other end side of the pipe path AL 12. One end sides of the pipe paths AL12A and AL12B are branched and connected to the branching portion AD 55.

In the pipe path AL7A, a branch portion AD6A is provided between the expansion valve a22A and the port A5Aa of the interior heat exchanger A5A.

The branch portion AD6A and the branch portion AD55 are connected by a pipe path AL 12A. The solenoid valve a16A is disposed on the pipe path AL 12A.

In the pipe path AL7B, a branch portion AD6B is provided between the expansion valve a22B and the port A5Ba of the interior heat exchanger A5B.

The branch portion AD6B and the branch portion AD55 are connected by a pipe path AL 12B. The solenoid valve a16B is disposed on the pipe path AL 12B.

A branch portion AD7 is provided between the branch portion AD5 in the pipe path AL11 and the port A3Aa of the 1 st external heat exchanger A3A. One end side of the pipe path AL13 is connected to the branch portion AD 7.

A branch portion AD77 is provided on the other end side of the pipe path AL 13.

The branching portion AD77 branches and connects to a pipe path AL13A and a pipe path AL 13B.

The pipe path AL13A connects the branch portion AD77, the solenoid valve a15A in the pipe path AL8A, and the port A5Ab of the interior heat exchanger A5A.

The pipe path AL13B connects the branch portion AD77, the solenoid valve 15B in the pipe path AL8B, and the port A5Bb of the interior heat exchanger A5B.

A check valve a32A and a check valve a32B are disposed in the pipe path AL13A and the pipe path AL13B, respectively, and the check valves a32A and a32B allow the flow only to the branch portion AD 77.

A check valve a33 is disposed between the branch portion AD5 and the branch portion AD7 in the pipe path AL11, and the check valve a33 allows only the flow to the branch portion AD 5.

The branch portion AD4 shown at the upper left in fig. 12 is connected to the port A2d of the four-way valve A2 through a block port M3d of the interior heat exchange block M3 by a pipe path AL 14. A check valve a34 is disposed in the pipe path AL14, and the check valve a34 allows a flow only to the branch portion AD 4.

The pipe path AL9 (between the branch portion AD3 and the port A2c of the four-way valve A2) is provided with a branch portion AD 8.

The branch portion AD8 and the inlet of the accumulator a6 are connected by a pipe path AL 15. The outlet of the accumulator a6 and the suction port of the compressor a1 are connected by a pipe path AL 16.

The refrigerant circuit 52R further has the following structure.

In the parallel circuit ALP1, a branch portion AD62 is provided between the port A3Bb of the 2 nd outdoor heat exchanger A3B, the pipe path AL4a, and the pipe path AL4 b.

In the pipe path AL11, a branch portion AD61 is provided between the port A3Aa of the 1 st outdoor heat exchanger A3A and the branch portion AD 7.

The branch portion AD61 and the branch portion AD62 of the parallel circuit ALP1 are connected by a pipe path AL 61. Hereinafter, the pipe path AL61 is also referred to as a bypass AL 61.

The bypass AL61 is provided with an electromagnetic valve a61V, a narrow tube a62, and a check valve a63 as opening and closing valves, and the check valve a63 allows only the flow from the branch portion AD61 to the branch portion AD 62.

The opening and closing operation of the solenoid valve a61V is controlled by the controller a41 (see fig. 13). The solenoid valve a61V is not included in the solenoid valve group a 11G.

The capillary tube, that is, the narrow tube a62 functions as a pressure reducer in the same manner as the expansion valve a 21. The narrow tube a62 serves as a pressure reducer, and the amount of refrigerant passing through the pressure reducer is larger than that of the expansion valve a 21.

A temperature sensor ATS1A is disposed in the pipe path AL13A, and the temperature sensor ATS1A measures the temperature of the refrigerant flowing through the indoor heat exchanger A5A in the vicinity of the port A5 Ab. Preferably, the temperature sensor ATS1A is disposed at a position close to the port A5Ab of the in-house heat exchanger A5A.

A temperature sensor ATS1B is disposed in the pipe path AL13B, and the temperature sensor ATS1B measures the temperature of the refrigerant flowing through the indoor heat exchanger A5B in the vicinity of the port A5 Bb. Preferably, the temperature sensor ATS1B is disposed at a position close to the port A5Bb of the in-house heat exchanger A5B.

A temperature sensor ATS2 is disposed in the vicinity of the port A3Ab of the 1 st outdoor heat exchanger A3A in the pipe path AL5 of the parallel circuit ALP1, and the temperature sensor ATS2 measures the refrigerant flowing through the section between the port A3Ab and the branch portion AD 1.

In the refrigerant circuit 52R, a piping path between the branch portion AD2 and the branch portion AD55 including the interior heat exchanger A5A and the branch portion AD3 and the branch portion AD77 is referred to as an interior heat exchanger unit A5 AU.

The piping route between the branch section AD2 and the branch section AD55 including the interior heat exchanger A5B and the branch section AD3 and the branch section AD77 is referred to as the interior heat exchanger unit A5 BU.

The interior heat exchanger unit A5AU and the interior heat exchanger unit A5BU are substantially the same piping paths. That is, in the refrigerant circuit 52R, two interior heat exchanger units are connected in parallel.

The above-described pipes are divided into the following pipes according to the phase of the refrigerant flowing therethrough.

In the following description, low pressure means: the pressure of the refrigerant raised by the compressor 1 is relatively low (high pressure).

The pipe paths AL1 and AL14 are high-pressure gas pipes through which a high-pressure gaseous refrigerant flows, the pressure of which is increased by the compressor a 1.

The pipe path AL2 is a gas pipe through which a high-pressure or low-pressure gaseous refrigerant flows.

The pipe paths AL6 and AL11 are high-pressure liquid pipes through which a high-pressure liquid refrigerant flows.

The pipe paths AL15 and AL16 are low-pressure gas pipes through which low-pressure gaseous refrigerant flows.

Next, the details of the outdoor heat exchanger a3 will be described with reference to fig. 14.

Fig. 14 is a schematic configuration diagram corresponding to a cross section of the off-bank heat exchanger a 3.

As described above, the outdoor heat exchanger a3 is formed of a finned tube type.

The 1 st bank external heat exchanger A3A and the 2 nd bank external heat exchanger A3B each have a plurality of paths, and the number of paths of the 1 st bank external heat exchanger A3A is equal to or less than the number of paths of the 2 nd bank external heat exchanger A3B.

The 1 st external heat exchanger A3A has the following configuration: the three paths are path AP1 through path AP 3.

The 2 nd external heat exchanger A3B has the following configuration: the six paths are paths AP 4-AP 9.

In the 1 st outdoor heat exchanger A3A, a path AP1 to a path AP3 are connected in parallel between the port A3Aa and the port A3 Ab.

The route AP1 to the route AP3 are arranged as follows: the regions do not overlap each other in the air blowing direction (the left-right direction in fig. 14), and are substantially independent on one surface on the suction side (hereinafter, also referred to as a suction surface).

Paths AP4 to AP9 are connected in parallel between the port A3Ba and the port A3Bb in the 2 nd outdoor heat exchanger A3B.

The paths AP4 to AP9 are configured as follows: substantially do not overlap each other in the air blowing direction, and are substantially independent areas on the suction surface.

The 1 st bank external heat exchanger A3A and the 2 nd bank external heat exchanger A3B are configured as follows: the 1 st outdoor heat exchanger A3A is on the upwind side of the ventilation outside air that is driven by the fan AF1 to flow in a certain direction. That is, the 1 st outdoor heat exchanger A3A is an upstream side heat exchanger, and the 2 nd outdoor heat exchanger A3B is a downstream side heat exchanger.

The refrigerating device 52 can be applied to various apparatuses and devices. For example, the present invention can be used for a refrigerator and a mobile refrigerator car having a refrigerator.

Fig. 15 is a side view showing an example of use loading on a refrigerator car AC provided with a refrigerator ACT, a part of which is a cut surface.

The refrigerator car AC includes: a freezer ACT, a freezer 52, and a vehicle body portion ACH having a power source for traveling and a traveling mechanism. The refrigerator ACT has a storage room ACA and a storage room ACB as two independent heat-insulating and heat-preserving rooms.

The interior heat exchanger A5A is disposed in the interior space ACVA of the warehouse ACA and exchanges heat with air in the interior space ACVA.

The interior heat exchanger A5B is disposed in the internal space ACVB of the storage room ACB and exchanges heat with the air in the internal space ACVB.

An outdoor heat exchanger 3 is disposed outside the freezer ACT (for example, above the driver's seat) and exchanges heat with the outside air.

The other components of the freezer 52 are disposed outside the freezer ACT. The arrangement position is not limited.

For example, the compressor a1 and the accumulator a6 are housed in the housing AS and provided below the vehicle body. Control unit a41 and input unit a42 are provided near the driver's seat. In particular, the input unit a42 is disposed at a place where the driver can easily operate.

The compressor a1 is an electric compressor and is driven by, for example, a battery or an inverter circuit as a power source. The compressor a1 is not limited to this electric compressor, and may be of a type using a driving power source (such as an engine or a motor) of the refrigeration vehicle AC as a driving source.

Next, the operation of the refrigeration apparatus 52 will be described with reference to fig. 16 to 26, taking the case of being mounted on the refrigeration vehicle AC as an example.

The refrigerator car AC can independently maintain four operation states of cooling, temperature raising, defrosting, and stop (neither cooling nor temperature raising) in two storage rooms ACA (as the 1 st room) and ACB (as the 2 nd room) by the operation of the refrigeration apparatus 52. The defrosting is performed by the interior heat exchangers A5A and A5B.

That is, the refrigeration apparatus 52 can selectively execute four operation modes of cooling, temperature raising, defrosting, and stopping for the interior heat exchangers A5A and A5B, respectively, under the control of the controller a 41. Therefore, as a combination of the operation modes, 16 operation modes including full stop can be executed for the two libraries ACA and ACB.

FIG. 16 is a table showing control states of 16 operation modes (mode numbers 1 to 16) including full stop. As shown in the table, the controller a41 selectively executes each operation mode by controlling the four-way valve a2, the solenoid valve group a11G as a release valve, and the fan group AFG (fans AF1, AF2A, and AF 2B).

That is, the four-way valve a2 and the solenoid valve group a11G serve as a flow path switching unit RK1, and the flow path through which the refrigerant flows in the refrigerant circuit 52R is selectively switched according to the operation mode under the control of the control unit a 41.

The 16 motion patterns are classified, for example, as follows:

two-compartment cooling operation (mode No. 1), two-compartment warming-up operation (mode No. 2), simultaneous cooling/warming-up operation (mode nos. 3 and 4), one-compartment cooling operation (mode nos. 5 and 6), one-compartment warming-up operation (mode nos. 7 and 8), defrosting operation (mode nos. 9 to 15), and full stop (mode No. 16).

Regarding the mode of the four-way valve a2, the control section a41 switches to the mode # a and the mode # B shown in fig. 17.

In this switching, the controller a41 switches to the mode # B when at least one of the stocker ACA and the stocker ACB is set to the operation mode for raising the temperature or defrosting, and switches to the mode # a otherwise.

The mode of the four-way valve a2 in the full stop (operation mode 16) is not limited. That is, the mode in the operation mode immediately before the stop may be maintained.

Regarding the type of the solenoid valve group a11G, the controller a41 controls the combination of the open state and the closed state of each valve in 8 types a to H.

Specifically, as shown in fig. 18, a total of 16 operation modes formed by the combination of four operation modes of the stocker ACA and the stocker ACB correspond to and control any one of the a to H patterns.

The type of the full stop (operation mode 16) is not limited. That is, the mode may be maintained in the operation mode immediately before the stop.

In the fan group AFG, the controller a41 turns ON the fan AF1 in all the operation modes 1 to 15 except the full stop (operation mode 16), turns ON the fans AF2A and AF2B when the cooling or heating of the respective warehouse rooms ACA and ACB is performed, and turns OFF the fans during the defrosting or stop.

Next, the operation modes (mode numbers 1 to 8) not including defrosting will be described with reference to fig. 19 to 24. In each figure, the operating fans are shaded. And, when the temperature of the air blown out by the fan is lower than the temperature of the air sucked in by the heat exchanger, the blown out air is indicated by white arrows; and when the temperature of the air blown out by the fan is higher than the temperature of the air sucked in by the heat exchanger, the black arrows indicate the temperature. The path through which the refrigerant flows is indicated by a thick line.

Here, the basic operation contents under the environmental conditions (the conditions where the outside air is not extremely high temperature) other than the negative pressure operation condition a will be described.

[1-1] two-compartment Cooling operation

< pattern No. 1: reference is made to FIG. 19

Mode in which the warehouse ACA and the warehouse ACB are cooled together.

The high-temperature and high-pressure gaseous refrigerant discharged from the discharge port of the compressor a1 to the pipe line AL1 flows from the port A2a of the four-way valve A2 in the mode # a to the pipe line AL2 through the port A2 b. In mode # a, port A2c and port A2d are also connected, but these ports do not function.

The refrigerant flowing into the pipe path AL2 flows into the 2 nd outdoor heat exchanger A3B of the outdoor heat exchanger A3 through the port A3Ba and flows out through the port A3 Bb.

The refrigerant flows out from the port A3Bb, passes through the check valve a31b and the open solenoid valve a11, and flows into the 1 st outdoor heat exchanger A3A from the port A3 Ab.

The refrigerant flowing into the port A3Ab flows out of the port A3Aa of the 1 st outdoor heat exchanger A3A and then flows into the pipe path AL 11.

In the outdoor heat exchanger A3, the fan AF1 is in an operating state, and outside air flows from the 1 st outdoor heat exchanger A3A to the 2 nd outdoor heat exchanger A3B.

The fan in the operating state is shaded, and the fan in the stopped state is painted in white, so that the two states can be distinguished. The same applies to the following description.

In the outside air flow state, the 2 nd bank out heat exchanger A3B and the 1 st bank out heat exchanger A3A function as a condenser integrally in the bank out heat exchanger A3. That is, the gaseous refrigerant discharged from the compressor a1 radiates heat to the outside air and condenses, and flows as a high-pressure liquid refrigerant from the port A3Aa into the pipe path AL 11.

Specifically, the refrigerant is a gaseous refrigerant in a gas phase at all of the inlet port A3Ba of the 2 nd outdoor heat exchanger A3B. The gaseous refrigerant flows through the 2 nd outdoor heat exchanger A3B, and is partially condensed (liquefied) by heat exchange with the outside air, so that the ratio of the liquid refrigerant to the gaseous refrigerant increases.

Accordingly, most of the refrigerant in the outlet of the 2 nd outdoor heat exchanger A3B, that is, the port A3Bb, is a gas-liquid mixed refrigerant of liquid refrigerant. Here, the ratio of the liquid refrigerant differs depending on the operating conditions.

Subsequently, the gas-liquid mixed refrigerant flowing out of the port A3Bb flows into the 1 st outdoor heat exchanger A3A from the port A3 Ab. In the 1 st outdoor heat exchanger A3A, heat exchange between the refrigerant and the outside air is continued, and the refrigerant becomes almost entirely in a liquid phase under high pressure in the outlet, that is, the port A3 Aa.

In the following description, when the outside air or the inside air deprives heat from the refrigerant through the heat exchanger and is discharged, the flow is indicated by black arrows. On the other hand, when the refrigerant takes heat and releases the heat, the flow is indicated by white arrows.

Since the refrigerant changes its phase from the gas phase to the liquid phase in the outdoor heat exchanger a3, the volume of the refrigerant decreases.

In the bank-exterior heat exchanger A3, the number of passages ANa (ANa: 3 in this example) of the 1 st bank-exterior heat exchanger A3A through which the refrigerant whose liquid phase ratio is increased by the volume reduction flows is smaller than the number of passages ANb (ANb: 6 in this example) of the 2 nd bank-exterior heat exchanger 3B through which the refrigerant whose gas phase ratio is high flows. Thus, the refrigerant flowing through the 1 st outdoor heat exchanger A3A has a higher flow velocity and a higher degree of supercooling than the refrigerant flowing through the 2 nd outdoor heat exchanger A3B as a liquid refrigerant.

The high-pressure liquid refrigerant flowing out of the port A3Aa into the pipe line AL11 passes through the check valve a33 and enters the accumulator a 4.

The liquid refrigerant remaining in the accumulator a4 according to the operating environment is retained.

For example, when the heat load in the reservoir ACA and the reservoir ACB is small, the amount of the circulating refrigerant may be small, and the remaining liquid refrigerant may be retained in the liquid receiver a 4. On the other hand, when the heat load in the reservoir ACA and the reservoir ACB is large, a large amount of the circulating refrigerant is required, and therefore, the amount of the liquid refrigerant staying in the liquid receiver a4 becomes small. Therefore, an optimum amount of refrigerant is always circulated in the refrigerant circuit 52R, and a high cooling capacity can be stably maintained.

The liquid refrigerant discharged from the accumulator a4 passes through the solenoid valve a13 in an open state to reach the branching unit AD2, and is branched to flow through the piping path AL7A on the side of the storage interior heat exchanger unit A5AU and the piping path AL7B on the side of the storage interior heat exchanger unit A5 BU.

First, the refrigerant flowing into the pipe path AL7A enters the expansion valve a22A via the solenoid valve a 14A. The refrigerant is decompressed and expanded in the expansion valve a22A to form a low-temperature gas-liquid mixed refrigerant, and flows into the interior heat exchanger A5A from the port A5 Aa.

The fan AF2A of the interior heat exchanger A5A is in an operating state. Therefore, in the indoor heat exchanger A5A, heat exchange can be performed between the refrigerant and the ventilated indoor air (hereinafter, ventilated indoor air).

By this heat exchange, the refrigerant takes heat and is gasified, and the ventilation internal air is sent out into the storehouse chamber ACA after being cooled (white arrow). Thereby, the storehouse ACA is cooled.

On the other hand, the refrigerant flowing into the pipe path AL7B enters the expansion valve a22B through the solenoid valve a 14B. The refrigerant is decompressed and expanded in the expansion valve a22B, and a low-temperature gas-liquid mixed refrigerant flows into the interior heat exchanger A5B from the port A5 Ba.

The fan AF2B of the interior heat exchanger A5B is in an operating state. Therefore, in the indoor heat exchanger A5B, heat exchange is performed between the refrigerant and the ventilation internal air.

By this heat exchange, the refrigerant takes heat and is gasified, and the ventilation internal air is sent out into the storage room ACB after being cooled (white arrow). Thereby, the reservoir ACB is cooled.

The refrigerant vaporized in the indoor heat exchangers A5A and A5B flows from the ports A5Ab and A5Bb to the electromagnetic valves a15A and a15B, respectively, and merges at the branch portion AD3, and returns to the suction port of the compressor A1 through the accumulator a6 by the pipe path AL15 and the pipe path AL 16.

[1-2] two-chamber temperature-raising operation

< pattern No. 2: reference is made to FIG. 20

A mode in which the storehouse ACA and the storehouse ACB are heated together.

The high-temperature and high-pressure gaseous refrigerant discharged from the discharge port of the compressor a1 to the pipe line AL1 flows from the port A2a of the four-way valve A2 in the mode # B to the pipe line AL14 through the port A2 d.

The refrigerant flowing into the pipe path AL14 passes through the check valve a34 and the branch portion AD4, and enters the liquid receiver a4 because the solenoid valve a13 is closed. In the above operation mode, when the liquid refrigerant is accumulated in the accumulator a4, the liquid refrigerant is compressed into the gaseous refrigerant, and only the gaseous refrigerant is instantaneously contained in the accumulator a 4.

The gas refrigerant having passed through the accumulator a4 passes through the branch portion AD5 and the pipe path AL12, and branches into the pipe path AL12A and the pipe path AL12B at the branch portion AD 55.

First, the gas refrigerant flowing into the pipe path AL12A passes through the solenoid valve a16A, and flows into the interior heat exchanger A5A from the port A5 Aa.

The fan AF2A of the interior heat exchanger A5A is in an operating state. Therefore, in the indoor heat exchanger A5A, heat exchange is performed between the refrigerant and the ventilation internal air, the refrigerant takes heat and is mostly condensed and liquefied to become a substantially liquid refrigerant, and the ventilation internal air is heated and sent to the interior of the storage room ACA (black arrow). Thereby, the warehouse ACA is warmed.

On the other hand, the gaseous refrigerant flowing into the pipe path AL12B passes through the solenoid valve a16B, and flows into the interior heat exchanger A5B from the port A5 Ba.

The fan AF2B of the interior heat exchanger A5B is in an operating state. Therefore, in the indoor heat exchanger A5B, heat exchange is performed between the refrigerant and the ventilation internal air, the refrigerant takes heat and is mostly condensed and liquefied into a substantially liquid refrigerant, and the ventilation internal air is heated and then sent into the storage chamber ACB (black arrow). Thereby, the storage room ACB is warmed.

The refrigerant flowing out of the interior heat exchangers A5A and A5B is a high-pressure substantially liquefied refrigerant, and includes a gaseous refrigerant in an amount corresponding to an operating environment such as a heat load in the storage room ACA and the storage room ACB.

The substantially liquefied high-pressure refrigerant flows into the pipe paths AL13A and AL13B from the ports A5Ab and A5Bb, passes through the check valves a32A and a32B, and merges at the branch portion AD 77. After the confluence at the branch section AD77, the liquid flows through the pipe path AL13 and the branch section AD7, passes through the pipe path AL11, and flows into the 1 st external heat exchanger A3A from the port A3 Aa.

The fan AF1 of the outdoor heat exchanger a3 is in an active state. Therefore, heat exchange between the liquid refrigerant and the ventilation outside air is performed in the 1 st outdoor heat exchanger A3A, and the liquid refrigerant is cooled and the degree of supercooling increases. That is, the 1 st outdoor heat exchanger A3A functions as a supercooling heat exchanger for the liquid refrigerant.

The uncondensed gaseous refrigerant flowing into the 1 st outdoor heat exchanger A3A together with the liquid refrigerant is also cooled by heat exchange with the ventilation outside air and completely liquefied.

After the heat exchange in the 1 st outdoor heat exchanger A3A, the liquid refrigerant flowing out of the port A3Ab passes through the solenoid valve a11 of the pipe path AL5 and the check valve a31a of the pipe path AL4a, and enters the expansion valve a 21.

In the expansion valve a21, the liquid refrigerant is decompressed and expanded to form a low-temperature gas-liquid mixed refrigerant. The heat exchanger A3B outside the 2 nd storage compartment flows into the port A3Bb through the pipe path AL 3.

In the 2 nd outdoor heat exchanger A3B, the refrigerant takes heat from the outside air by heat exchange with the ventilating outside air, and the low-temperature liquid refrigerant is gasified, thereby forming a complete gaseous refrigerant. At this time, the 2 nd external heat exchanger A3B functions as an evaporator.

The gaseous refrigerant flows out from the port A3Ba to the pipe path AL2, passes through the accumulator a6, and returns to the suction port of the compressor a 1.

[1-3] Cooling/warming Simultaneous operation

Mode No. 3 and mode No. 4 are operation modes in which the temperature raising operation and the cooling operation are simultaneously performed, that is, one of the two storage rooms is raised in temperature and the other is cooled.

< Pattern No. 3 (warehouse ACA warming, warehouse ACB cooling): reference is made to FIG. 21>

In this operation mode, the interior heat exchanger unit A5AU corresponding to the storage room ACA is subjected to the temperature increasing operation, and the interior heat exchanger unit A5BU corresponding to the storage room ACB is subjected to the cooling operation.

The flow of the refrigerant from the compressor a1 to the branch portion AD55 is the same as the pattern number 2.

In the branching portion AD55 and thereafter, in the mode number 3, since the solenoid valve a16B is in the closed state, the refrigerant (gaseous refrigerant) does not branch at the branching portion AD55, and flows only into the pipe path AL 12A.

The gas refrigerant flowing into the pipe path AL12A passes through the solenoid valve a16A, and flows into the interior heat exchanger A5A from the port A5 Aa.

The fan AF2A of the interior heat exchanger A5A is in an operating state. Therefore, in the indoor heat exchanger A5A, heat exchange is performed between the refrigerant and the ventilation internal air.

In this heat exchange, the refrigerant takes heat, most of the refrigerant is condensed and liquefied to form a liquid refrigerant, and the ventilation internal air is sent out into the storehouse chamber ACA after being heated. Thereby, the warehouse ACA is warmed.

The refrigerant flowing out of the interior heat exchanger A5A is a high-pressure substantially liquefied refrigerant, and includes a gaseous refrigerant in an amount corresponding to an operating environment such as a thermal load in the reservoir CA.

The substantially liquefied high-pressure refrigerant flows from the port A5Ab into the pipe path AL13A, passes through the check valve a32A, passes through the branch portion AD77 and the pipe path AL13, and enters the pipe path AL11 from the branch portion AD 7. Then, the heat exchanger A3A of the 1 st out-of-bank heat exchanger A3 flows into the port A3 Aa.

The fan AF1 of the outdoor heat exchanger a3 is in an active state. Therefore, in the 1 st outdoor heat exchanger A3A, heat exchange between the liquid refrigerant and the ventilation outside air is performed, and the liquid refrigerant is deprived of heat and the degree of supercooling increases after the temperature is decreased. That is, the 1 st outdoor heat exchanger A3A functions as a supercooling heat exchanger for the liquid refrigerant.

The uncondensed gaseous refrigerant flowing into the 1 st outdoor heat exchanger A3A together with the liquid refrigerant is also deprived of heat by heat exchange with the ventilation outside air, is cooled, and is completely liquefied.

After the heat exchange in the 1 st outdoor heat exchanger A3A, the liquid refrigerant flows out of the port A3Ab into the pipe line AL6, passes through the solenoid valve a12, and reaches the branch portion AD 2.

In this mode, since the solenoid valves a13 and a14A are closed, the liquid refrigerant flows into the pipe path AL7B in which the solenoid valve a14B is open, and enters the expansion valve a 22B.

In the expansion valve a22B, the liquid refrigerant is decompressed and expanded to form a low-temperature gas-liquid mixed refrigerant, and flows into the interior heat exchanger A5B from the port A5 Ba.

The fan AF2B of the interior heat exchanger A5B is in an operating state. Therefore, in the indoor heat exchanger A5B, the gas-liquid mixed refrigerant takes heat from the ventilation air by heat exchange and evaporates, and becomes a complete gaseous refrigerant. The in-bank heat exchanger A5B functions as an evaporator.

On the other hand, the ventilated internal air is sent out to the storehouse ACB after being cooled. Thereby, the reservoir ACB is cooled.

The gasified refrigerant flows into the pipe path AL8B from the port A5Bb, passes through the electromagnetic valve a15B and the accumulator a6, and returns to the suction port of the compressor A1.

< Pattern No. 4 (Cooling of warehouse Chamber CA, warming of warehouse Chamber CB): reference is made to FIG. 22

In pattern No. 4, the in-house heat exchanger unit that is heated and the in-house heat exchanger unit that is cooled are exchanged with each other with respect to pattern No. 3.

That is, the open/close states of the solenoid valve a16A and the solenoid valve a16B are reversed, the solenoid valve a16A is closed, the solenoid valve a16B is opened, and the high-pressure gaseous refrigerant from the compressor A1 flows into the interior heat exchanger A5B.

Then, the open/close states of the solenoid valve a14A and the solenoid valve a14B are reversed, the solenoid valve a14A is opened, the solenoid valve a14B is closed, and the liquid refrigerant cooled in the 1 st exterior heat exchanger A3A flows into the interior heat exchanger A5A.

Thereby, the warehouse ACA is cooled, and the warehouse ACB is warmed.

In the

operation modes

3 and 4 in which the temperature rise and the cooling are performed simultaneously, as described above, the degree of supercooling of the liquid refrigerant is increased in the 1 st outdoor heat exchanger A3A. Therefore, the cooling capacity of the in-compartment heat exchanger in the cooling operation increases to the extent of the increase in the supercooling degree.

[1-4] one-compartment Cooling operation

< pattern numbers 5, 6: reference is made to FIG. 23

One compartment cooling operation is to cool one of the two compartments ACA, ACB while the other is stopped. Here, the operation stop includes two cases, that is: the continuous operation is stopped, and the interior temperature of the storage chamber reaches the set temperature during the two-chamber cooling operation, and is temporarily stopped.

The mode number 5 is an operation mode for cooling the storage chamber ACA and stopping the operation of the storage chamber ACB, and the refrigerant flow passage is indicated by a thick solid line in fig. 23.

That is, the mode number 5 is an operation mode in which: in the mode number 1 (see fig. 19) of the two-compartment cooling operation, the solenoid valve a14B is closed, and the fan AF2B is stopped while the refrigerant does not flow into the interior heat exchanger unit A5 BU.

The solenoid valve a15B is opened, and the refrigerant in the inoperative interior heat exchanger A5B is discharged to the pipe path AL15 through the pipe path AL 8B. After a predetermined time has elapsed from the start of the operation in the mode number 5, the refrigerant in the interior heat exchanger A5B may be released, and the solenoid valve a15B may be closed.

The phase state of the refrigerant in the refrigerant passage common to the pattern number 1, the heat exchange action in the exterior heat exchanger a3 and the interior heat exchanger A5A, and the like are the same as those in the case of the pattern number 1.

The mode number 6 is an operation mode for cooling the storage room ACB and stopping the operation of the storage room ACA. The refrigerant flow path is different only between the branch portion AD2 and the branch portion AD3, and the flow path shown by a thick broken line in fig. 23 is between them.

That is, in mode No. 6, the solenoid valve a14A is closed to stop the flow of the refrigerant into the interior heat exchanger unit A5AU and the fan AF2A is stopped in mode No. 1 (see fig. 19) of the two-compartment cooling operation (the fans AF2A and AF2B in fig. 23 represent the operation state in mode No. 5 and the operation state is reversed in mode No. 6).

The solenoid valve a15A is opened, and the refrigerant in the inoperative interior heat exchanger A5A is discharged to the pipe path AL15 through the pipe path AL 8A. After a predetermined time has elapsed from the start of the operation in the mode number 6, the refrigerant in the interior heat exchanger A5A may be released, and the solenoid valve a15A may be closed.

The phase state of the refrigerant in the refrigerant passage common to the pattern number 1, the heat exchange action in the exterior heat exchanger a3 and the interior heat exchanger A5B, and the like are the same as those in the case of the pattern number 1.

[1-5] one-compartment temperature-raising operation

< pattern No. 7, 8: reference is made to FIG. 24

The one-room temperature raising operation is to raise the temperature of one of the two warehouse rooms ACA and ACB and stop the operation of the other warehouse room ACA and ACB. Here, the operation stop includes two cases, that is: the continuous operation is stopped, and the temperature in the interior of the storage chamber reaches the set temperature during the two-chamber temperature raising operation, and is temporarily stopped.

The mode number 7 is an operation mode for raising the temperature of the storage room ACA and stopping the operation of the storage room ACB, and the refrigerant flow path thereof is indicated by a thick solid line in fig. 24.

That is, the mode number 7 is an operation mode in which: in the mode number 2 (see fig. 20) of the two-compartment temperature increasing operation, the solenoid valve a16B is closed, and the fan AF2B is stopped while the refrigerant does not flow into the interior heat exchanger unit A5 BU.

The solenoid valve a15B is opened, and the refrigerant in the inoperative interior heat exchanger A5B is discharged to the pipe path AL9 through the pipe path AL 8B. After a predetermined time has elapsed from the start of the operation in the mode number 7, the refrigerant in the interior heat exchanger A5B may be released, and the solenoid valve a15B may be closed.

The phase state of the refrigerant in the refrigerant passage common to the pattern number 2, the heat exchange action in the exterior heat exchanger a3 and the interior heat exchanger A5A, and the like are the same as those in the case of the pattern number 2.

The mode number 8 is an operation mode for raising the temperature of the storage chamber ACB and stopping the operation of the storage chamber ACA, and the refrigerant flow passage is different only between the branch portion AD55 and the branch portion AD77, and a flow passage indicated by a thick broken line in fig. 24 is formed therebetween.

That is, in mode No. 8, the solenoid valve a16A is closed to stop the flow of refrigerant into the interior heat exchanger unit A5AU and the fan AF2A is stopped (the fans AF2A and AF2B in fig. 24 show the operating state in mode No. 7, and the operating state is reversed in mode No. 8) with respect to mode No. 2 (see fig. 20) of the two-compartment temperature raising operation

The solenoid valve a15A is opened, and the refrigerant in the inoperative interior heat exchanger A5A is discharged to the pipe path AL9 through the pipe path AL 8A. After a predetermined time has elapsed from the start of the operation in the mode number 8, the refrigerant in the interior heat exchanger A5A may be released, and the solenoid valve a15A may be closed.

The phase state of the refrigerant in the refrigerant passage common to the pattern number 2, the heat exchange action in the exterior heat exchanger a3 and the interior heat exchanger A5B, and the like are the same as those in the case of the pattern number 2.

[1-6] defrost operation (defrosting of heat exchangers A5A, A5B in the interior of the refrigerator)

For example, after the warehouse ACA is cooled for a long time in any one of the

operation modes

1, 4, and 5, moisture contained in the air in the warehouse ACA may freeze and adhere to the fins of the indoor heat exchanger A5A in the form of frost. Since the fins are clogged with frost and the heat exchange is blocked, the defrosting operation of the in-bank heat exchanger A5A is performed to defrost the fins. The defrosting operation is also performed on the in-house heat exchanger A5B.

Since the refrigerant circuit 52R is a heat pump type, defrosting is performed by a so-called reverse cycle.

Specifically, the temperature raising operation is performed on the heat exchanger to be defrosted, and the fan corresponding to the heat exchanger is stopped. Details of each operation mode will be described below with reference to fig. 24 and the like.

< Pattern No. 9>

The operation mode is an operation mode for performing the defrosting operation for defrosting only the interior heat exchanger A5A, and the fan AF2A is stopped (OFF) in the operation mode of mode number 7 for raising the temperature only in the interior heat exchanger A5A.

< Pattern No. 10>

The operation mode is an operation mode for performing the defrosting operation for defrosting only the interior heat exchanger A5B, and the fan AF2B is stopped (OFF) in the operation mode of mode number 8 for raising the temperature only in the interior heat exchanger A5B.

< Pattern No. 11>

In the defrosting operation mode in which both the interior heat exchanger A5A and the interior heat exchanger A5B are defrosted, both the fan AF2A and the fan AF2B are stopped (OFF) in the operation mode of the two-compartment temperature increasing operation (mode number 2).

The freezer 52 may defrost one of the two compartments ACA and ACB of the refrigerator ACT, and cool or warm the other compartment.

< Pattern No. 12>

The operation mode is an operation mode in which the interior heat exchanger A5A is defrosted and the interior heat exchanger A5B is subjected to the temperature increasing operation, and the fan AF2A is stopped (OFF) in the operation mode of the two-compartment temperature increasing operation (mode number 2).

< Pattern No. 13>

The operation mode is an operation mode in which the interior heat exchanger A5B is defrosted and the interior heat exchanger A5A is subjected to the temperature increasing operation, and the fan AF2B is stopped (OFF) in the operation mode of the two-compartment temperature increasing operation (mode number 2).

< Pattern No. 14>

The operation mode is an operation mode in which the interior heat exchanger A5A is defrosted and the interior heat exchanger A5B is cooled, and the fan AF2A is stopped (OFF) in the operation mode of mode number 3 in the simultaneous cooling/heating operation.

< Pattern No. 15>

The operation mode is an operation mode in which the interior heat exchanger A5B is defrosted and the interior heat exchanger A5A is cooled, and the fan AF2B is stopped (OFF) in the operation mode of mode number 4 in the simultaneous cooling/heating operation.

The refrigerating apparatus 52 is capable of executing the temperature raising operation after the above-described cooling operation under the general environmental condition in japan that the outside air is not extremely high in temperature, and immediately raising the temperature in the refrigerator which has been cooled to a low temperature.

On the other hand, as described in example 1, when the outside air is extremely high in temperature, for example, during a heat period, the two-compartment cooling operation of pattern number 1 is executed and the two-compartment heating operation of pattern number 2 is executed immediately thereafter, and in this case, the following phenomenon may occur.

That is, the following phenomenon occurs: the low-temperature liquid refrigerant condensed in the in-compartment heat exchangers A5A and A5B cooled to a low temperature flows into the 1 st out-compartment heat exchanger A3A warmed to a high temperature by the outside air, and boils and evaporates at this time.

The refrigerant vaporized by boiling evaporation cannot sufficiently pass through the expansion valve a21 of the pipe path AL4a, and therefore the amount of refrigerant circulating through the refrigerant circuit 52R decreases, and a negative-pressure operation state is achieved, and the temperature raising capability decreases.

In the refrigeration apparatus 52, the bypass operation is performed as a preventive measure for preventing the occurrence of the negative pressure operating state and when the negative pressure operating state is generated in the temperature increasing operation switched from the cooling operation.

Specifically, the control unit a41 determines whether or not the bypass operation is executed in the sequence example described later, and controls switching between the bypass operation and the temperature increasing operation.

First, the circulation and operation of the refrigerant when the bypass operation is performed under an environmental condition (negative pressure operation condition a) in which the negative pressure operation state can be established will be described.

The bypass operation in the case where the two-compartment cooling operation in pattern No. 1 is performed in advance and the temperature raising operation is performed while the temperature is sufficiently low from the in-compartment heat exchangers A5A and A5B will be described.

First, in the operating state of pattern number 2 of the two-compartment temperature increasing operation, the bypass operation is executed by further opening the solenoid valve a 61V.

Since the air inside the storage room ACA and the storage room ACB is already at a low temperature during the cooling operation, the refrigerant substantially becomes a liquid refrigerant by the heat exchange in the interior heat exchangers A5A and A5B and flows through the piping path AL 11.

When the electromagnetic valve a61V is opened, the low-temperature and high-pressure liquid refrigerant flowing out of the interior heat exchangers A5A and A5B is branched at a branch portion AD61 in the pipe path AL11 as shown in fig. 25.

Specifically, as in the case of the two-chamber temperature increasing operation of pattern No. 2, the following are: the flow (main flow) flowing from the port A3Aa into the 1 st outdoor heat exchanger A3A and the flow generated only during the bypass operation, that is, the flow (bypass flow) flowing through the bypass AL 61.

The liquid refrigerant flowing into the 1 st outdoor heat exchanger A3A as a main flow is heated by the outside air to become a high temperature in the 1 st outdoor heat exchanger A3A, and thus the temperature thereof is raised.

Under the negative pressure operation condition a, the temperature of the 1 st external heat exchanger A3A warmed by the outside air is higher than the boiling point of the inflowing liquid refrigerant.

Therefore, the liquid refrigerant is heated by the 1 st outdoor heat exchanger A3A, boiled and evaporated to become a gaseous refrigerant, and flows into the expansion valve a 21.

However, since the gaseous refrigerant cannot sufficiently pass through the expansion valve a21, the refrigerant from the main flow substantially does not flow into the piping path after the expansion valve a21, or flows only in a small amount.

On the other hand, the liquid refrigerant flowing into the bypass AL61 as a bypass flow is decompressed by the narrow tube a62, passes through the check valve a63, flows through the branch portion AD62, and flows into the 2 nd outdoor heat exchanger A3B from the port A3 Bb.

The liquid refrigerant from the bypass flow flowing into the 2 nd outdoor heat exchanger A3B is evaporated by heat exchange with the outside air. Also, since this heat exchange is also performed between the 2 nd bank out heat exchanger A3B itself, the 2 nd bank out heat exchanger A3B is cooled.

As the 2 nd bank exterior heat exchanger A3B cools, the temperature of the 1 st bank exterior heat exchanger A3A sharing fins also decreases.

Due to this temperature drop, the boiling evaporation of the main stream flowing into the 1 st external heat exchanger A3A is stopped at an initial stage. Therefore, the amount of liquid refrigerant flowing out of the 1 st outdoor heat exchanger A3A, that is, the amount of refrigerant passing through the expansion valve a21, is increased rapidly.

Therefore, the amount of refrigerant circulating through the refrigerant circuit 52R is not drastically reduced, and the refrigerant is quickly recovered even if the amount is reduced.

Thus, in the bypass operation, by opening the solenoid valve a61V and generating the bypass flow through the bypass AL61, the refrigerant can be supplied to the 2 nd outdoor heat exchanger A3B, and the amount of the refrigerant circulating in the refrigerant circuit 52R is secured to a certain amount or more without drastically decreasing, and the negative pressure operation is hardly generated. Even if the negative pressure operation is generated, the temperature is initially returned to the normal temperature increasing operation.

Thus, the refrigeration apparatus 52 can satisfactorily raise the temperature of the cooled interior in a short time.

The bypass operation is not limited to the following applications: after the two-compartment cooling operation of pattern number 1, the two-compartment temperature increasing operation of pattern number 2 is performed. The bypass operation can also be applied to the following cases: a temperature raising operation of raising the temperature of the cooled bank from a state in which the cooled bank exists after the one-room cooling operation is performed; the details are as follows.

Next, a method of determining whether or not to perform the bypass operation when switching from the cooling operation to the temperature increasing operation will be described. The determination is made by the controller a41 based on the temperatures At1A, At1B, and At2 obtained from the temperature sensors ATS1A, ATS1B, and ATS 2.

The temperature sensor ATS1A measures the temperature At1A (see fig. 13) of the refrigerant flowing out of the interior heat exchanger A5A, and sends the measurement result to the controller a 41.

The temperature sensor ATS1B measures the temperature At1B (see fig. 13) of the refrigerant flowing out of the interior heat exchanger A5B, and sends the measurement result to the controller a 41.

The temperature sensor ATS2 measures the temperature At2 (see fig. 13) of the refrigerant flowing out of the 1 st outdoor heat exchanger A3A, and sends the measurement result to the controller a 41.

The control unit a41 controls the operation of the bypass operation according to the sequence example shown in fig. 26 (flowchart).

First, the controller a41 executes the two-compartment cooling operation in response to an external instruction (AS 1).

Subsequently, the controller a41 switches to the two-chamber temperature increasing operation in response to an external instruction (AS 2). Thereby, the two-chamber temperature increasing operation is started.

The control section a41 determines whether any of the following values is less than a specific value α 2, that is: the value of the detected temperature of the temperature sensor ATS2, that is, the temperature At2 (At1A-At2), is subtracted from the detected temperature from the temperature sensor ATS1A, that is, the temperature At1A, and the value of the detected temperature of the temperature sensor ATS2, that is, the temperature At2 (At1B-At2), is subtracted from the detected temperature from the temperature sensor ATS1B, that is, the temperature At1B (AS 3).

The value α 2 is set as appropriate in accordance with the specification of the refrigeration apparatus 52, the operating environment of the refrigeration vehicle AC, and the like. For example 5 (deg).

The value α 2 may be set to either a negative value or a positive value. The lower limit is about-3 (deg) under the usual specification.

Therefore, in order to establish (AS3) when the value α 2 is set to a negative value, At least one of (At1A-At2) and (At1B-At2) is less than 0.

Similarly, when the value α 2 is set to 0 (zero), At least one of (At1A-At2) and (At1B-At2) is 0 or less.

When the value α 2 is a positive number, either one of (At1A-At2) and (At1B-At2) may be less than 0 or more.

When the determination of (AS3) is No, the controller a41 determines whether or not the operation stop instruction is given from the outside (AS8), and when No, the determination is continued (AS 3).

When the determination of (AS8) is Yes, the temperature increasing operation is stopped (AS9), and the operation is ended.

When the determination of (AS3) is Yes, it is determined whether or not the elapsed time Atm after the determination of Yes is equal to or longer than a specific time β 2 seconds (AS 4).

The specific time β 2 is set as appropriate in accordance with the operating characteristics of the refrigeration apparatus 52 and the like. For example 20 seconds.

When the determination of (AS4) is No, the process moves to (AS8), and is executed when there is No stop instruction (AS 3).

AS long AS the determination of (AS3) is Yes, the elapsed time Atm is accumulated.

When the determination of (AS4) is Yes, it is determined to perform the bypass operation. That is, the electromagnetic valve a61V is opened (AS 5). Thereby, the bypass operation is performed.

During execution of the bypass operation, it is determined whether or not the following two values are equal to or greater than a specific value α 2: the value of the detected temperature of the temperature sensor ATS2, that is, the temperature At2, is subtracted from the detected temperature from the temperature sensor ATS1A, that is, the temperature At1A, and the value of the detected temperature of the temperature sensor ATS2, that is, the temperature At2, is subtracted from the detected temperature from the temperature sensor ATS1B, that is, the temperature At1B (AS 6).

When the determination of (AS6) is No, controller a41 continues the determination (AS 6).

When the determination of (AS6) is Yes, the possibility that the negative pressure operation of control unit a41 is cancelled or changed to the negative pressure operation is very small, the bypass operation is stopped, and the normal temperature increasing operation is returned to. That is, the electromagnetic valve a61V is closed (AS 7).

The controller a41 executes (AS7) and moves to (AS 8).

Thus, after the transition from the two-compartment cooling operation to the two-compartment warming operation, the controller a41 compares the temperatures At1A and At1B of the refrigerant flowing out of the interior heat exchangers A5A and A5B with the temperature At2 of the refrigerant flowing out of the 1 st exterior heat exchanger A3A.

If any one of the value obtained by subtracting the temperature At2 from the temperature At1A and the value obtained by subtracting the temperature At2 from the temperature At1B is less than the specific value α 2 and the state continues for the specific elapsed time Atm or longer, it is determined that the negative pressure operation is generated or the negative pressure operation is likely to be generated, and the bypass operation is executed.

During the execution of the bypass operation, when the temperature At1A, the temperature At1B, and the temperature At2 are monitored, and the value obtained by subtracting the temperature At2 from the temperature At1A and the value obtained by subtracting the temperature At2 from the temperature At1B are both equal to or greater than the specific value α 2, the bypass operation is shifted to the normal temperature-increasing operation.

The bypass operation is performed when switching from the cooling operation to the temperature increasing operation, and is also performed appropriately in accordance with the temperatures At1A, At1B, and At2 during the temperature increasing operation.

Therefore, even if the external environment changes with time, the negative pressure operation can be prevented from occurring even if the negative pressure operation condition a is met.

In this way, the refrigeration apparatus 52 has the bypass path ABP (see fig. 12) including the bypass AL61 including the solenoid valve a61V, the narrow tube a62, and the check valve a63, and thereby can perform the bypass operation and the negative pressure operation is less likely to occur. Even in the negative pressure operation, the temperature initially returns to the normal temperature increasing operation.

Therefore, the freezer 52 can warm the interior of the refrigerator well in a short time.

Cooling operation in the temperature raising operation after the one-compartment cooling operation, the temperature of the cooled reservoir is compared with the temperature At 2. This is substantially the same as the control of embodiment 1.

The refrigeration apparatus 52 described above includes:

a refrigerant circuit 52R; and a process for the preparation of a coating,

a flow path switching unit RK1 (four-way valve a2, solenoid valve group a11G) that selectively switches A1 st refrigerant flow path R1, a2 nd refrigerant flow path R2, and A3 rd refrigerant flow path R3 (see fig. 16) as a flow path through which refrigerant flows;

the refrigerant circuit 52R includes: a1 st refrigerant flow passage R1 including a1 st pipe path (pipe paths AL1, AL14, AL11, AL12, AL12A) LH1 for guiding the refrigerant discharged from the compressor a1 to the in-bank heat exchanger A5A, a2 nd pipe path (pipe paths AL13A, AL13, AL11) LH2 for guiding the refrigerant condensed and liquefied in the in-bank heat exchanger A5A to the out-bank heat exchanger A3A, and A3 rd pipe path (pipe paths AL6, AL7B) LH3 (see fig. 21) for guiding the refrigerant of the liquid phase supercooled in the out-bank heat exchanger A3A to the in-bank heat exchanger A5B;

a2 nd refrigerant flow passage R2 including a4 th pipe path (pipe paths AL1, AL14, AL11, AL12, AL12A, AL12B) LH4 for branching and introducing the refrigerant discharged from the compressor a1 to the interior heat exchanger A5A and the interior heat exchanger A5B, and A5 th pipe path (pipe paths AL13A, AL13B, AL13, AL11) LH5 (see fig. 20) for introducing the refrigerant into a liquid phase in the interior heat exchangers A5A and A5B to the exterior heat exchanger A3A; and a process for the preparation of a coating,

the 3 rd refrigerant flow passage R3 includes a6 th pipe path (pipe paths AL1 and AL2) LH6 for guiding the refrigerant of the gas phase discharged from the compressor 1 to the exterior heat exchanger A3, and a 7 th pipe path (pipe paths AL11, AL10, AL7A, and AL7B) LH7 for branching and guiding the refrigerant condensed and liquefied in the exterior heat exchanger A3 to the interior heat exchanger A5A and the interior heat exchanger A5B (see fig. 19).

A part of the 4 th pipe path in the 2 nd refrigerant passage R2 (see fig. 20) and a part of the 7 th pipe path in the 3 rd refrigerant passage R3 are common, that is, a common pipe LK. Specifically, the pipe path AL11 is located between the branch portion AD4 and the branch portion AD 5. A liquid receiver a4 is disposed on the general-purpose pipe LK.

The refrigeration apparatus 52 of embodiment 2 can defrost the outdoor heat exchanger a3 as follows.

If the

pattern numbers

2, 7, and 8, that is, the two-compartment simultaneous warming-up or one-compartment warming-up operation in which the 2 nd outdoor heat exchanger A3B of the outdoor heat exchanger A3 functions as an evaporator is performed for a long time, moisture contained in the outside air may freeze and adhere to the fins of the 2 nd outdoor heat exchanger A3B in the form of frost.

At this time, although the refrigeration apparatus 52 is not classified into the operation mode of fig. 16, the defrosting operation of the outdoor heat exchanger a3 can be performed.

In the operation mode of mode number 1 of the two-compartment cooling operation, this defrosting operation is an operation in which all of the fans AF1, AF2A, AF2B are stopped (OFF).

The refrigeration apparatus 51 and the refrigerator car C described in detail above have the heat pump type refrigerant circuit 51R. The refrigeration apparatus 52 and the refrigeration vehicle AC have a heat pump type refrigerant circuit 52R.

Therefore, not only the thermal energy obtained by the operation of the compressors 1 and a1 but also the thermal energy obtained from the outside air by the outside heat exchanger 3 and the outside heat exchanger A3 in the operation mode of the temperature increasing operation of the inside heat exchanger 5 and the inside heat exchangers A5A and A5B, respectively, and the thermal energy obtained from the inside air of the cooled storage room in the operation mode of the simultaneous temperature increasing and cooling operation are used to increase the temperature of the storage room having the temperature increased in accordance with the thermal energy obtained from the inside air of the cooled storage room. Thereby, more excellent temperature raising ability can be obtained.

The refrigerant circuit 51R and the refrigerant circuit 52R flow the refrigerant to the liquid receiver 4 and the liquid receiver a4, respectively, in the operation modes other than the full stop.

For example, in the refrigerant circuit 52R, in the operation mode (mode numbers 2 to 4, 7 to 15) in which the temperature raising or defrosting operation is performed on at least one of the plurality of interior heat exchangers A5A, A5B, the liquid receiver a4 is filled with the gaseous refrigerant.

Thus, in these operation modes, since there is no liquid refrigerant remaining in the liquid receiver a4, all the refrigerant in the refrigerant circuit 52R can be used, and even if the temperature rise or defrosting operation is continuously performed, the refrigerant shortage is unlikely to occur. The same applies to the refrigerant circuit 51R.

In the operation mode (

mode numbers

1, 5, and 6) in which the temperature raising and defrosting operation is not involved, the liquid refrigerant may be stored in the liquid receiver a4 in the refrigerant circuit 52R.

Specifically, when a situation occurs in which excess refrigerant is generated during the cooling operation, the excess refrigerant can be secured in the accumulator a 4.

On the other hand, when an operating condition occurs in which excess refrigerant is generated during the temperature raising and defrosting operation, in the 1 st outdoor heat exchanger A3A, excess refrigerant corresponding to an appropriate amount of refrigerant circulating in the refrigerant circuit 52R can be secured as liquid refrigerant.

Thus, even if the cooling operation, the temperature raising operation and the defrosting operation are continuously performed, the pressure in the circuit can be maintained at an optimum level, and a high operation capability can be maintained. Therefore, the set temperature in the chamber can be maintained stably with high accuracy.

When the interior heat exchangers A5A and A5B are operated in the operation mode (

mode numbers

1, 5, and 6) including no temperature increase and defrosting in the exterior heat exchanger A3 of the refrigerant circuit 52R, the 2 nd interior heat exchanger A3B and the 1 st interior heat exchanger A3A function as a condenser integrally.

Thus, the freezer 52 has a high cooling capacity.

In an environment other than the negative pressure operation condition a, when at least one of the inside heat exchangers A5A and A5B is operated in an operation mode (mode numbers 2 to 4, 7 to 15) of the temperature increase or defrosting operation, the 1 st outside heat exchanger A3A functions as a supercooling heat exchanger.

As a result, the cooling capacity of the refrigerating device 52 is improved to the extent of the increase in the supercooling degree.

Further, the gas-liquid mixed refrigerant flows out of the ports A5Ab and A5Bb of the interior heat exchangers A5A and A5B which are in the temperature increasing or defrosting operation. That is, since the refrigerant is condensed in the heat exchanger from the ports A5Aa and A5Ba to the ports A5Ab and A5Bb, the heat is radiated to the entire heat exchanger, and the heat exchange efficiency of the heat exchanger is improved.

In the refrigerant circuit 52R, each of the plurality of interior heat exchangers A5A, A5B has a pair of ports for inputting and outputting the refrigerant, and each of the pair of ports has a dual-system input/output piping path.

For example, the interior heat exchanger A5A of the refrigerant circuit 52R will be described with reference to fig. 12, and the interior heat exchanger A5A includes a pair of ports A5Aa and A5Ab for input and output.

The port A5Aa has two paths, that is, a pipe path AL7A connected to the branch portion AD2 and a pipe path AL12A connected to the branch portion AD 55.

The port A5Ab has two paths, that is, a pipe path AL8A connected to the branch portion AD3 and a pipe path AL13A connected to the branch portion AD 77.

Here, if the combination of the pipe path AL7A and the pipe path AL8A is defined as the 1 st path and the combination of the pipe path AL12A and the pipe path AL13A is defined as the 2 nd path, the refrigerant circuit 52R flows through the 2 nd path in the operation mode in which the cooling operation is performed on the interior heat exchanger A5A and the temperature increasing or defrosting operation is performed while the refrigerant flows through the 1 st path. The same applies to the in-house heat exchanger A5B.

That is, in the interior heat exchangers A5A and A5B having the 1 st path and the 2 nd path, the refrigerant flows in the same direction in either operation mode. Specifically, the flow is from ports A5Aa, A5Ba to ports A5Ab, A5 Bb.

When the operation mode is switched from the operation mode in which the interior heat exchangers A5A and A5B function as condensers to the operation mode in which the interior heat exchangers A5A and A5B function as evaporators, the refrigerant returned to the compressor a1 from the interiors of the interior heat exchangers A5A and A5B is a gas-liquid mixed refrigerant.

Therefore, by switching the operation mode, a large amount of liquid refrigerant is not returned to the compressor a1, and there is no fear that the compressor a1 is damaged by the liquid compression.

Further, this switching operation can be performed without balancing the pressure in the refrigerant circuit after the refrigeration apparatus 52 is temporarily stopped. Therefore, the operation efficiency of the refrigerating apparatus 52 is improved.

The refrigeration apparatus 52 has a heat pump type refrigerant circuit 52R, and can perform any one of the cooling operation and the temperature increasing operation by circulating the refrigerant at all times without alternately circulating the refrigerant with respect to the plurality of interior heat exchangers A5A and A5B.

Thus, the internal temperatures of the storage rooms ACA and ACB in which the internal heat exchangers A5A and A5B are respectively disposed are not easily changed from the set temperature to the upper or lower temperature, and can be maintained with high accuracy and stability with respect to the set temperature.

Fig. 31 is a diagram for explaining an application operation of the bypass operation in the refrigeration apparatus 52. As shown in fig. 31, the one-compartment cooling operation is performed, and the cooled storage compartment is switched to the defrosting operation for the temperature raising operation or the defrosting operation for raising the temperature, and in this case, the bypass operation described in embodiment 1 can be performed (black arrows in fig. 31).

In addition, the two-compartment cooling operation is performed, and the cooled storage compartment is switched to the defrosting operation for the temperature raising operation or the defrosting operation, and in this case, the bypass operation described in embodiment 2 can be performed (white arrows in fig. 31).

The structure and control procedure in the refrigeration apparatus 51 of embodiment 1 and the refrigeration apparatus 52 of embodiment 2 described above are not limited to those described above, and may be changed within a range not departing from the gist of the present invention.

< variation: reference is made to FIG. 27>

The refrigeration apparatus 51 of example 1 may be changed to the refrigeration apparatus 151 described below.

The refrigeration apparatus 151 of the modification includes a refrigerant circuit 151R in which only the 2 nd outdoor heat exchanger 3B is provided except the 1 st outdoor heat exchanger 3A in the outdoor heat exchanger 3 in the refrigerant circuit 51R of the refrigeration apparatus 51.

The refrigeration apparatus 151 has the same structure as the refrigeration apparatus 51 except that the 1 st external heat exchanger 3A is removed (see fig. 2).

That is, the outdoor heat exchanger 3 of the refrigeration apparatus 151 includes one outdoor heat exchanger 3B, and is connected by a pipe path L62 (referred to as the present path L62) between the pipe paths L3 and L4 from the branch portion D61 to the parallel circuit LP 1.

The temperature sensor TS2 is disposed on the present path L62.

In fig. 28, the flow path of the mode change a, which is the cooling operation of the refrigerating apparatus 151, is indicated by a thick line.

The mode change a differs from the mode a in the refrigeration apparatus 51 in that: the refrigerant passing through the piping path L4 of the parallel circuit LP1 directly passes through the present path L62 and the branch portion D61 to reach the branch portion D1.

In fig. 29, the flow path of mode change B, which is the operation of raising the temperature of the refrigerating apparatus 151, is shown by a thick line.

The mode change B differs from the mode B in the refrigeration apparatus 51 in that: the refrigerant having passed through the pipe path L9 and the branch portion D61 passes through the main path L62 directly and reaches the pipe path L3 of the parallel circuit LP 1.

The controller 31 controls the opening and closing of the electromagnetic valve 61V in the temperature increasing operation after the cooling operation, by referring to the procedure (S1 to S9) described with reference to fig. 11 which is the same as that of the refrigeration apparatus 51.

Under the negative pressure operation transition condition a, when any one of the piping paths L8, L9 and the main path L62 (hereinafter referred to as an intermediate path TK: see fig. 27) in the refrigerant circuit 151R is exposed to the outside air, the low-temperature liquid refrigerant that has been sufficiently cooled and flowed out by the low-temperature in-compartment heat exchanger 5 formed in the cooling operation may be warmed to boil, evaporate and gasify when passing through the intermediate path TK.

Since the gasified refrigerant cannot pass through the expansion valve 7 as in the case of the refrigeration apparatus 51, the refrigerant circuit 151R is in a negative pressure operation state.

It is determined by the procedure (S1 to S9) based on the temperatures t1 and t2 that the possibility that the control unit 31 will be in the negative pressure operating state or the negative pressure operating state is high, and the bypass operation is executed by appropriately opening the electromagnetic valve 61V.

The refrigeration apparatus 151 also has a bypass path BP composed of a bypass L61 including the electromagnetic valve 61V, the narrow tube 62, and the check valve 63, and thereby can perform the bypass operation, and the negative pressure operation is less likely to occur. Even if the negative pressure operation occurs, the temperature initially returns to the normal temperature increasing operation.

Thus, according to the refrigeration apparatus 151 of the modified example, even in the arrangement state where at least a part of the intermediate path TK from the inside heat exchanger 5 to the outside heat exchanger 3 is in contact with the outside air, the occurrence of the negative pressure operation can be avoided by performing the bypass operation when the outside air is in the high temperature operation environment.

The above-described embodiments and variations can be combined as much as possible.

The number of the heat exchangers in the heat storage unit is not limited to 2, and may be 3 or more.

For example, a refrigerant circuit having a plurality of inside heat exchangers and a single outside heat exchanger may be used. In this case, the control unit may determine whether or not the bypass operation is to be performed based on the temperatures of the refrigerant flowing out of the plurality of interior heat exchangers and the temperature of the refrigerant flowing into the exterior heat exchanger in the temperature increasing operation in the order described with reference to fig. 26 (AS1 to AS 9).

When there are a plurality of interior heat exchangers, a single temperature sensor may be used instead of a plurality of temperature sensors for measuring the temperature of the refrigerant flowing out of each interior heat exchanger during the temperature raising operation.

For example, as shown by a broken line in fig. 12, one temperature sensor ATS1 may be disposed on the pipe path AL13 through which the refrigerants flowing out of the plurality of interior heat exchangers A5A and A5B merge.

The controller a41 may determine whether or not to perform the bypass operation based on the temperature At1 of the refrigerant flowing out of and merging with the interior heat exchangers A5A and A5B in the pipe path AL13 during the temperature increase operation and the temperature At2 of the refrigerant measured by the temperature sensor ATS1 and measured by the temperature sensor ATS 2. The determination procedure at this time may be the procedure described with reference to fig. 11 (S1 to S9).

In

embodiments

1 and 2 and the modification described above, the control units 31 and a41 execute whether or not to determine the bypass operation based on the temperature of the refrigerant flowing during the temperature increasing operation.

In contrast, as a variation of the control method, the control unit 31 or a41 may control the operation of the

refrigerant circuit

51R, 52R, or 151R so that the bypass operation is executed for a certain time period when the control unit switches to the temperature raising operation for raising the temperature of the low-temperature reservoir after the cooling operation is executed.

This modification is effective when the usage environment of the refrigeration vehicle on which the

refrigeration apparatuses

51, 52, and 151 are mounted is set to the negative pressure operation condition a in many cases.

In the above description, the expansion valves 7 and a21 may be referred to as a1 st decompressor, and the narrow tube 62 and a62 may be referred to as a2 nd decompressor.

Claims

1. A refrigeration apparatus provided with a refrigerant circuit including an interior heat exchanger and an exterior heat exchanger, the refrigeration apparatus being capable of selectively performing a cooling operation for cooling a storage chamber in which the interior heat exchanger is disposed and a heating operation for heating the storage chamber,

the external heat exchanger includes:

the refrigerant circuit further includes:

a2 nd piping path connecting the inside heat exchanger and the 1 st outside heat exchanger;

a bypass path connecting the 2 nd piping path and the 1 st piping path between the 1 st decompressor and the 2 nd external heat exchanger, and having an opening/closing valve and a2 nd decompressor disposed therein; and a process for the preparation of a coating,

and a control unit that opens the on-off valve to allow the refrigerant to flow into the 2 nd bank exterior heat exchanger via the bypass path when a liquid refrigerant flows into the 1 st bank exterior heat exchanger during the temperature raising operation and boils to evaporate and then generates a negative pressure operation or when a negative pressure operation may be generated.

2. The refrigeration apparatus according to claim 1, further comprising:

a1 st temperature sensor for measuring a temperature of the refrigerant flowing through the 2 nd pipe path; and a process for the preparation of a coating,

a2 nd temperature sensor for measuring a temperature of the refrigerant flowing between the 1 st external heat exchanger and the 1 st decompressor in the 1 st piping path;

the control unit controls the opening/closing operation of the opening/closing valve based on the 1 st temperature measured by the 1 st temperature sensor and the 2 nd temperature measured by the 2 nd temperature sensor.

3. A refrigeration apparatus provided with a refrigerant circuit including an interior heat exchanger and an exterior heat exchanger, the refrigeration apparatus being capable of selectively performing a cooling operation for cooling a storage chamber in which the interior heat exchanger is disposed and a heating operation for heating the storage chamber,

the heat exchanger in the bank includes a heat exchanger in the 1 st bank and a heat exchanger in the 2 nd bank;

the refrigerant circuit further includes:

a2 nd piping path having one end connected to the 1 st external heat exchanger and the other end branched at a branch portion to connect the 1 st internal heat exchanger and the 2 nd internal heat exchanger;

a bypass path which connects the branching portion in the 2 nd piping path and the 1 st outdoor heat exchanger, and connects the 1 st decompressor and the 2 nd outdoor heat exchanger in the 1 st piping path, and in which an on-off valve and a2 nd decompressor are arranged; and a process for the preparation of a coating,

4. The refrigeration apparatus according to claim 3, further comprising:

a1 st temperature sensor and a2 nd temperature sensor, the 1 st temperature sensor measuring a temperature of the refrigerant flowing between the 1 st interior heat exchanger and the branch portion in the 2 nd piping path, the 2 nd temperature sensor measuring a temperature of the refrigerant flowing between the 2 nd interior heat exchanger and the branch portion in the 2 nd piping path; and a3 rd temperature sensor for measuring a temperature of the refrigerant flowing between the 1 st outdoor heat exchanger and the 1 st decompressor in the 1 st piping path;

the control unit controls the opening and closing operation of the opening and closing valve based on the 1 st to 3 rd temperatures measured by the 1 st to 3 rd temperature sensors, respectively.

5. The refrigeration apparatus according to claim 3, comprising:

a1 st temperature sensor that measures a temperature of the refrigerant flowing between the branch portion of the 2 nd piping path and the 1 st interior heat exchanger; and a process for the preparation of a coating,

the control unit controls the opening and closing operation of the opening and closing valve based on the 1 st temperature and the 2 nd temperature measured by the 1 st temperature sensor and the 2 nd temperature sensor, respectively.

6. The refrigeration apparatus according to claim 1 or claim 3, wherein the outdoor heat exchanger includes a fin connected across the 1 st outdoor heat exchanger and the 2 nd outdoor heat exchanger.

7. The refrigeration apparatus according to claim 1 or claim 3, wherein an amount of the refrigerant flowing through the 2 nd decompressor is larger than an amount of the refrigerant flowing through the 1 st decompressor.

8. A method of operating a refrigeration apparatus according to claim 2 or claim 5, the method comprising:

9. A method of operating a refrigeration system according to claim 4, the method comprising: