JP2001153480A - Refrigerating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a drop in reliability of a refrigerating plant 10 by stabilizing the composition of a non-azeotropic mixed refrigerant flowing through a refrigerant circuit 12. SOLUTION: A refrigerating plant provided with a refrigerant circuit 12 which performs a thermo-compression refrigerating cycle by using the non- azeotropic mixed refrigerant is provided with a storing section 43 which makes a liquid refrigerant to flow out while the section 43 stores the mixed refrigerant on a high-pressure liquid line. The outlet sides of evaporators 31 and 23 are connected to the suction side of a compressor 21 not through any accumulator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigeration system using a non-azeotropic mixed refrigerant, and more particularly to a technique for stabilizing the composition of a non-azeotropic mixed refrigerant circulating in a refrigerant circuit. .

[0002]

2. Description of the Related Art Conventionally, a refrigerant circuit of a refrigerating apparatus for performing a vapor compression type refrigerating cycle generally comprises a compressor, a condenser, an expansion valve, and an evaporator connected in order by refrigerant piping. ing. As this type of refrigerant circuit, there is a refrigerant circuit in which an accumulator is attached to a suction pipe of a compressor as disclosed in Japanese Patent Application Laid-Open No. H11-72257. In the accumulator, the liquid refrigerant mixed in the low-pressure gas refrigerant is separated from the gas refrigerant. Therefore, FIG.
As shown in (1), a part of the refrigerant in the circuit stays in the accumulator (1) in the state of the liquid refrigerant (RL).

On the other hand, non-azeotropic mixed refrigerants such as R407C are:
It is constituted by mixing a plurality of refrigerants having different boiling points. If the ratio of each composition refrigerant, that is, the composition ratio is different, the characteristics will be different. Therefore,
The composition ratio is strictly determined so that the non-azeotropic refrigerant exhibits predetermined characteristics.

[0004]

When a non-azeotropic refrigerant mixture is used in the refrigerant circuit, an accumulator is required.
The low-pressure refrigerant flowing into (1) is basically a gas refrigerant (RG), but when a liquid refrigerant (RL) is contained therein, the liquid refrigerant (RL) is a non-azeotropic mixed refrigerant. The high boiling point refrigerant (R134a in the case of R407C) which is difficult to evaporate has a high composition ratio, and the low boiling point refrigerant (R407C in the case of R407C) which is easily evaporated.
32) is in a low composition ratio.

In addition, since the liquid refrigerant (RL) has a higher density than the gas refrigerant (RG), the liquid refrigerant contains a large amount of high-boiling refrigerant in the accumulator (1) in which the refrigerant stays. In contrast, the gas refrigerant (RG) has a state in which the ratio of the high-boiling refrigerant is considerably lower than the original composition ratio of the non-azeotropic mixed refrigerant. Therefore, from the accumulator,
As described above, the gas refrigerant (RG) in which the ratio of the high-boiling refrigerant is low and the ratio of the low-boiling refrigerant is high flows out and is sucked into the compressor.

As described above, in the above-described example, the non-azeotropic mixed refrigerant circulates in the refrigerant circuit in a state different from the original composition ratio. For this reason, there is a possibility that the refrigerating apparatus may not be able to exhibit its original ability due to a change in refrigerant characteristics due to an increase in high pressure or the like, and the reliability of the refrigerating apparatus may be reduced, such as a decrease in operation efficiency.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to stabilize the composition of a non-azeotropic mixed refrigerant flowing in a refrigerant circuit to thereby improve the refrigeration system. The purpose is to prevent the reliability from deteriorating.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a refrigerating apparatus using a non-azeotropic mixed refrigerant, wherein the refrigerant is circulated in a refrigerant circuit while being stored in a storage section such as a high-pressure receiver. .

Specifically, the solution taken by the present invention presupposes a refrigeration apparatus having a refrigerant circuit (12) for performing a vapor compression refrigeration cycle using a non-azeotropic mixed refrigerant. And
The high pressure liquid line of the refrigerant circuit (12) is provided with a storage part (43) for discharging the liquid refrigerant while storing the refrigerant.

[0010] In the above configuration, it is preferable that the refrigerant circuit (12) has no accumulator on the suction side of the compressor (21). That is, it is preferable that the outlet side of the evaporator (31, 23) is directly connected to the suction side of the compressor (21).
In this case, “direct” means the evaporator (31,23) and the compressor
(21) is not used in the sense of excluding the configuration of connecting a four-way switching valve or the like between the evaporator (31,
23) and the compressor (21) are connected without using an accumulator.

Further, in the above configuration, the refrigerant circuit (12)
A switching mechanism (22) for reversing the direction of circulation of the refrigerant in the chamber, and a direction control circuit (41) for flowing the liquid refrigerant from the condenser (23, 31) into the storage section (43) in each circulation direction. Preferably, an expansion mechanism (EV) is connected downstream of the storage section (43).

In the above configuration, the liquid seal prevention passage (27) connected between the liquid pipe between the storage part (43) and the expansion mechanism (EV) and the discharge pipe of the compressor (21). ) Is provided, and the liquid-sealing prevention passage (27) is preferably configured as a one-way passage that allows refrigerant to flow from the liquid pipe side to the discharge pipe side.

Further, in the above configuration, the discharge pipe temperature sensor (Td), the condenser temperature sensor (Tc, Te), the evaporator temperature sensor (Te, Tc), and each temperature sensor (Td, Tc, Te) ) Is preferably provided with a control means (50) for controlling the degree of opening of the expansion mechanism (EV) in accordance with the output of (EV).

In the above configuration, R407C can be used as the non-azeotropic mixed refrigerant.

-Operation- In the above solution, the non-azeotropic mixed refrigerant such as R407C circulates in the refrigerant circuit (12) while the surplus is stored in the storage part (43) such as a high-pressure receiver. This reservoir
(43) has a high pressure, most of which exists in a liquid refrigerant state, and the amount of gas is smaller than that of liquid. The storage unit (4
The gas density in 3) is very small compared to the liquid density. From the above, even if R32 is slightly gasified, the liquid refrigerant stored in the storage part (43) has a composition ratio of the high-boiling refrigerant and the low-boiling refrigerant that is the original composition of the non-azeotropic mixed refrigerant. This is a state that is almost the same as the ratio, and since this liquid refrigerant flows out of the storage section (43), a refrigerant having a stable composition ratio is
It will circulate inside.

In particular, in the above configuration, if the accumulator is not used on the suction side of the compressor (21), the composition does not fluctuate in the low-pressure gas line.

[0017] When the direction of circulation of the refrigerant is configured to be reversible, a direction control circuit (41) is provided upstream of the storage section (43), and an expansion mechanism (EV) is provided downstream of the storage section (43). Regardless of whether the direction is switched forward or reverse, the refrigerant flows from the compressor (21) to the condensers (23, 31), the direction control circuit (41), the storage unit (43), the expansion mechanism (EV), and the evaporator. The refrigeration cycle is performed by circulation returning to the compressor (21) through (31, 23). At that time, high pressure storage
As the liquid refrigerant flows out while the surplus refrigerant is stored in (43),
Also, a refrigerant having a stable composition ratio circulates in the circuit (12).

When the liquid seal prevention passage (27) is provided, when the operation of the compressor (21) is stopped, even if the refrigerant accumulated in the storage section (43) expands due to an increase in the ambient temperature, The expanded refrigerant escapes from the discharge pipe side of the compressor (21) to the heat exchanger (23, 31) through the liquid seal prevention passage (27).

Further, the opening degree of the expansion mechanism (EV) is determined by each temperature sensor.
When controlled using (Td, Tc, Te), the operating evaporator (31,2
The discharge pipe temperature can be adjusted to an appropriate value for the temperature of 3) and the temperature of the condenser (23, 31).
The change in the state of the refrigerant changes accurately on a predetermined Mollier diagram, and the composition is further stabilized.

[0020]

Therefore, according to the above solution, R40
Since the non-azeotropic refrigerant such as 7C circulates in the refrigerant circuit (12) in a stable state that is almost the same as the original composition ratio, there is almost no change in the refrigerant characteristics, and the refrigeration system (10) has its original capacity. Can be demonstrated stably. Therefore, a decrease in operation efficiency is suppressed, and the reliability of the refrigeration system (10) can be improved. For this reason, providing the storage section (43) in the high-pressure liquid line and not using an accumulator on the suction side of the compressor (21) requires a refrigerant circuit (1) using a non-azeotropic mixed refrigerant.
It can be said that 2) is very suitable.

When the direction of circulation of the refrigerant in the refrigerant circuit (12) is configured to be reversible, for example, in an air conditioner using a non-azeotropic mixed refrigerant, a case where cooling operation is performed and a case where heating operation is performed are described. In either case, stable operation can be performed.

If a liquid seal prevention passage (27) is provided,
Due to the liquid refrigerant accumulated in the storage section (43), the storage section (4
Abnormal pressure rise around 3) can be prevented.

When the opening degree of the expansion mechanism (EV) is adjusted using the temperature sensors (Td, Tc, Te), the composition of the refrigerant can be further stabilized, so that the reliability of the apparatus can be further improved. It is possible to increase.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, the refrigeration apparatus of the present embodiment
(10) is a so-called separate type air conditioner (10) in which one outdoor unit (20) is connected to one indoor unit (30), and the refrigerant of the air conditioner (10) is The circuit (12) is configured to perform a vapor compression refrigeration cycle using a non-azeotropic mixed refrigerant R407C.

The outdoor unit (20) comprises a compressor (21), a four-way switching valve (switching mechanism) (22), an outdoor heat exchanger (23), an auxiliary heat exchanger (24), and an expansion circuit (40). These form a single heat source unit. The indoor unit (30) includes an indoor heat exchanger (31) and constitutes a single utilization unit.

The compressor (21) and the four-way switching valve (22)
And outdoor heat exchanger (23), auxiliary heat exchanger (24) and expansion circuit (40)
And the indoor heat exchanger (31) are connected in order by a refrigerant pipe (11) to form a refrigerant circuit (12) in which the refrigerant circulates and performs heat transfer. The refrigerant circuit (12) is the outdoor heat exchanger (23)
A liquid line (1L) including an expansion circuit (40) and a gas line (1G) including a compressor (21) are provided between the auxiliary heat exchanger (24) and the indoor heat exchanger (31). Is configured. In the present embodiment, no accumulator is provided on the suction side of the compressor (21).

The compressor (21) is, for example, of a scroll type whose operating frequency (operating capacity) is variably adjusted by an inverter. On the discharge side of the compressor (21), a muffler (25) for reducing the operation noise of the compressor (21)
Is connected. The muffler (25) has a check valve function that allows only the flow of the refrigerant in the direction from the compressor (21) to the four-way switching valve (22).

The four-way switching valve (22) operates during cooling operation as shown in FIG.
1 during the heating operation, and switches as shown by the broken line in FIG. 1 to reverse the circulation direction of the refrigerant in the refrigerant circuit (12). Then, the outdoor heat exchanger (2
3) and the auxiliary heat exchanger (24) are heat source side heat exchangers that function as a condenser during the cooling operation and function as an evaporator during the heating operation, and an outdoor fan (Fo) is provided in the vicinity thereof. I have. Further, the indoor heat exchanger (31) is a use side heat exchanger that functions as an evaporator during the cooling operation and functions as a condenser during the heating operation, and an indoor fan (Fr) is provided in the vicinity thereof. .

The expansion circuit (40) is configured to reduce the pressure of the refrigerant. The expansion circuit (40) includes a direction control circuit (41) formed of a bridge circuit and the direction control circuit (4).
And a one-way passage (42) connected to (1). The direction control circuit (41) performs the cooling operation and the heating operation,
Heat exchanger (23, 24), which then functions as a condenser,
The liquid refrigerant from (31) is configured to be guided to the one-way passage (42).

In the one-way passage (42), a receiver (reservoir) (43) located on the upstream side for storing the refrigerant and allowing the liquid refrigerant to flow out, and an electronically adjustable opening located on the downstream side. An expansion valve (expansion mechanism) (EV) is arranged in series. With the above configuration, the receiver (43) is always an electronic expansion valve (EV)
And a high-pressure liquid refrigerant from the condensers (23, 24) and (31) flows in regardless of the refrigerant circulation direction. Note that a filter (26) for removing dust in the refrigerant is arranged between the receiver (43) and the electronic expansion valve (EV).

More specifically, the direction control circuit (41) includes a first inflow path (44), a first outflow path (45), a second inflow path (46), and a second inflow path (46).
The outflow path (47) is connected in a bridge shape. Each of the inflow channels (44, 46) and the outflow channels (45, 47) is provided with a check valve (CV, CV,...).

The first inflow path (44) is connected to the outdoor heat exchanger (23).
Forms a refrigerant flow from the first connection point (P1) to which the first connection point (P1) is connected to the second connection point (P2) to which the upstream end of the one-way passage (42) is connected. In addition, the first outflow path (45) is a one-way path (4
A refrigerant flow is formed from the third connection point (P3) to which the downstream end of (2) is connected to the fourth connection point (P4) to which the indoor heat exchanger (31) is connected.

The second inflow path (46) forms a refrigerant flow from the fourth connection point (P4) to the second connection point (P2). The second outflow channel (47) forms a refrigerant flow from the third connection point (P3) to the first connection point (P1).

The one-way passage (42) is provided between the receiver (43) and the electronic expansion valve (EV) (more specifically, between the filter (26) and the electronic expansion valve (EV)). A (high-pressure liquid line) is connected to a discharge pipe of the compressor (21) via a liquid seal prevention passage (27) for preventing liquid seal when the compressor (21) is stopped. The liquid seal prevention passage (27) is a one-way passage that allows the flow of the refrigerant from the liquid pipe side to the discharge pipe side, and includes a check valve (CV) in the path.

A bypass passage (49) is connected between an upper portion of the receiver (43) and a downstream side of the electronic expansion valve (EV) in the one-way passage (42) which is always a low-pressure liquid line.
An electromagnetic valve (SV) is provided in the bypass passage (49),
The gas refrigerant in the receiver (43) can be drawn out.

On the other hand, the discharge pipe of the compressor (21) has a discharge pipe temperature sensor (Td) for detecting the discharge pipe temperature of the compressor (21).
Is arranged. In addition, an outdoor air temperature sensor (Ta) that detects an outdoor air temperature is disposed at an air suction port of the outdoor unit (20), and the outdoor heat exchanger (23) has a condensing temperature during a cooling operation and a condensing temperature during a heating operation. An external heat exchange temperature sensor (Tc) for detecting an external heat exchange temperature that is an evaporation temperature is provided. Further, at the air inlet of the indoor unit (30), a room temperature sensor (Tr) for detecting indoor air temperature is arranged, and the indoor heat exchanger (31) has an evaporating temperature during a cooling operation and an evaporation temperature during a heating operation. An internal heat exchange temperature sensor (Te) for detecting an internal heat exchange temperature that is a condensing temperature is arranged.

A high-pressure protection pressure switch (HS) which detects a high-pressure refrigerant pressure and outputs a high-pressure protection signal when the high-pressure refrigerant pressure excessively rises is provided to the discharge pipe of the compressor (21).
Is arranged. A low-pressure protection pressure switch (LS1) that detects a low-pressure refrigerant pressure and turns on when a low-pressure refrigerant pressure is excessively low to output a low-pressure protection signal is provided in the suction pipe of the compressor (21). A low-pressure control pressure switch (LS2) that detects a refrigerant pressure and turns on when the low-pressure refrigerant pressure reaches a predetermined value to output a low-pressure control signal;

The above temperature sensors (Td, Ta, Tc, Tr, T
e), high pressure protection pressure switch (HS), low pressure protection pressure switch
The output signals of (LS1) and the low-pressure control pressure switch (LS2) are input to a controller (50) as control means, and the controller (50) is configured to control the air conditioning operation based on the input signal. ing.

The controller (50) controls each device to perform a cooling operation and a heating operation, and also performs control to stabilize the composition of the non-azeotropic mixed refrigerant flowing in the refrigerant circuit (12). It is configured.

Specifically, the controller (50) divides the operating frequency of the inverter of the compressor (21) into a predetermined number of frequency steps N, for example. Control. Further, the controller (50) calculates the optimum value of the discharge pipe temperature that gives the optimum refrigerating effect from the condensation temperature and the evaporation temperature detected by the external heat exchange temperature sensor (Tc) and the internal heat exchange temperature sensor (Te). The opening degree of the electronic expansion valve (EV) is controlled by setting the valve opening degree so that the discharge pipe temperature becomes the optimum value.

By performing such control, the refrigerant circuit (1)
When the refrigerant circulates in 2), the operation on the determined Mollier diagram is guaranteed, and as a result, the fluctuation of the composition of the non-azeotropic mixed refrigerant is suppressed. That is, the composition ratio of R32 to R134a in R407C is stabilized.

The refrigerant circuit (12) of this embodiment is a circuit that does not use an accumulator on the suction side of the compressor (21) as described above. For this reason, control is performed such that the degree of superheat of the refrigerant sucked into the compressor (21) is sufficiently large,
By adopting a structure for adjusting the amount of liquid refrigerant flowing out from the receiver (43), liquid back to the compressor (21) is prevented.

-Operating operation- Next, a specific operating operation of the air conditioner (10) will be described.

First, during the cooling operation cycle, the compressor (2
The gas refrigerant discharged from 1) is condensed and liquefied in the outdoor heat exchanger (23) and the auxiliary heat exchanger (24), and the liquid refrigerant passes through the first inflow path (44) and is received by the receiver (43). Is stored once. Then, the liquid refrigerant flows out of the receiver (43), and the electronic expansion valve (EV)
After the pressure is reduced by the first outlet passage (45), the indoor heat exchanger (31)
And return to the compressor (21).

On the other hand, during the heating operation cycle, the compressor (2
The gas refrigerant discharged from 1) is condensed and liquefied in the indoor heat exchanger (31), and the liquid refrigerant is temporarily stored in the receiver (43) through the second inflow path (46). And the liquid refrigerant is the receiver
After flowing out from (43) and depressurized by the electronic expansion valve (EV), the auxiliary heat exchanger (24) and the outdoor heat exchanger (23) pass through the second outflow path (47).
And return to the compressor (21). At that time, the circulation operation of the refrigerant is performed while the surplus refrigerant is stored in the receiver (43).

In both the cooling operation cycle and the heating operation cycle, the solenoid valve (SV) is normally closed so that the gas refrigerant does not flow out of the receiver (43).

In the above operation, the pressure in the receiver (43) is high, and even if R32 gas refrigerant is generated due to the surrounding conditions, the amount is small, and the gas density is smaller than the liquid density. And extremely small. Therefore, the receiver
The composition of the liquid refrigerant flowing out of (43) hardly changes from the original composition of the non-azeotropic mixed refrigerant R407C used in this circuit (12), and the liquid refrigerant having such a stable composition is obtained. It flows out of the receiver (43) and circulates in the circuit (12).

In each operation cycle, the controller (50) controls the capacity of the compressor (21) by setting the frequency step N to an appropriate value, and also controls the external heat exchange temperature sensor (T
c) and the internal heat exchange temperature sensor (Te) calculates the optimum value of the discharge pipe temperature that gives the optimum refrigeration effect from the condensation temperature and the evaporation temperature detected by the sensor, and controls the valve so that the discharge pipe temperature becomes the optimum value. Set the opening. Then, a pulse signal for obtaining the valve opening degree is transmitted to the electronic expansion valve (25), and the electronic expansion valve (EV)
Control the opening degree of the air conditioner and perform air conditioning operation corresponding to the indoor load.

By this, when the non-azeotropic refrigerant mixture is circulated in the refrigerant circuit (12), the operation on the predetermined Mollier diagram is guaranteed.
The ratio between R32 and R134a in 407C can be stabilized.

Further, in the present embodiment, a circuit without using an accumulator on the suction side of the compressor (21) is used. However, as described above, the degree of superheating of the refrigerant sucked into the compressor (21) is sufficiently increased. Such control is performed and the amount of the liquid refrigerant flowing out of the receiver (43) is adjusted, so that liquid back to the compressor (21) does not occur. Since the accumulator is not used, the composition ratio of the refrigerant does not fluctuate due to the stagnation of the refrigerant on the suction side of the compressor (21) unlike the related art.

In the present embodiment, when the operation is stopped, the liquid refrigerant in the receiver (43) expands due to an increase in ambient temperature or the like with the electronic expansion valve (EV) and the solenoid valve (SV) closed. Also, this refrigerant flows from the one-way passage (42) to the liquid seal prevention passage (27).
And escapes to the heat exchanger (23, 31) side.
That is, liquid sealing is prevented.

-Effects of Embodiment- As described above, according to the present embodiment, in both the heating operation and the cooling operation, the non-azeotropic mixed refrigerant R407C used is of high pressure. The excess amount is stored in the receiver (43), and the circulation amount is circulated in the refrigerant circuit (12) while adjusting the circulation amount. In addition, since the inside of the receiver (43) has a high pressure, most of the liquid exists in a liquid refrigerant state, and the density of the gas is very small compared to the density of the liquid.
Even if R32 is gasified, the liquid refrigerant stored in the receiver (43) has a composition ratio that is almost the same as the original composition ratio of R407C. The refrigerant having such a stable composition ratio circulates through the circuit (12), and the composition ratio does not fluctuate on the suction side of the compressor (21). The harmony device (10) can exhibit its original ability stably. Therefore, a decrease in driving efficiency is also suppressed,
The reliability of the device (10) can be increased.

Further, since the opening degree of the electronic expansion valve (EV) is controlled by using the temperature sensors (Td, Tc, Te), the change in the state of the refrigerant can be accurately determined on a predetermined Mollier diagram. Will be changed. As a result, the composition is further stabilized, so that the reliability of the device can be further improved.

In the present embodiment, even if the refrigerant flows into the receiver (43) in a state where the composition of the refrigerant slightly fluctuates, the refrigerant has a high pressure in the receiver (43). Is corrected to a state close to the original composition ratio. Therefore, it is possible to reliably prevent the composition ratio of R407C from greatly changing during operation.

Further, since the liquid-sealing prevention passage (27) is provided, even if the ambient temperature increases when the operation is stopped, it is possible to prevent the pressure from abnormally increasing.

[0057]

Other Embodiments of the Invention The present invention may be configured as follows with respect to the above embodiment.

For example, in the above embodiment, one indoor unit (30) is connected to one outdoor unit (20), but a plurality of indoor units are connected to one outdoor unit (20). The type to which the unit (30) is connected may be used. In the above embodiment, the refrigeration apparatus of the present invention is configured as an air conditioner capable of performing a heating operation and a cooling operation. However, the present invention is directed to an air conditioner performing only a heating operation or performing only a cooling operation. The present invention is also applicable to refrigeration equipment other than the air conditioner.

The refrigerant used is not limited to R407C, and other non-azeotropic mixed refrigerants can be used.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an accumulator in a conventional refrigeration apparatus.

[Explanation of symbols]

(10) Air conditioner (refrigerator) (12) Refrigerant circuit (20) Outdoor unit (21) Compressor (22) Four-way switching valve (switching mechanism) (23) Outdoor heat exchanger (condenser, evaporator) (27) Liquid seal prevention passage (30) Indoor unit (31) Indoor heat exchanger (evaporator, condenser) (41) Direction control circuit (43) Receiver (reservoir) (50) Controller (control means) (EV ) Expansion mechanism (Td) Discharge pipe temperature sensor (Tc) External heat exchange temperature sensor (condenser temperature sensor, evaporator temperature sensor) (Te) Internal heat exchange temperature sensor (evaporator temperature sensor, condenser temperature sensor)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuo Fujiwara 1304 Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd. Sakai Seisakusho Kanaoka Plant F-term (reference) 3L092 AA12 AA14 BA05 BA21 BA27 DA01 DA03 EA02 FA24 FA27 FA34

Claims (6)

[Claims] 1. A refrigeration system comprising a refrigerant circuit (12) for performing a vapor compression refrigeration cycle by using a non-azeotropic mixed refrigerant, comprising: a storage section for discharging a liquid refrigerant while storing the refrigerant in a high-pressure liquid line. A refrigeration apparatus comprising (43). 2. The refrigeration system according to claim 1, wherein the refrigeration system is constituted by a refrigerant circuit (12) having no accumulator on the suction side of the compressor (21). 3. A switching mechanism (22) for reversing the direction of circulation of the refrigerant in the refrigerant circuit (12), and a condenser (23, 31) for each circulation direction.
Direction control circuit (4) that allows the liquid refrigerant from
The refrigeration apparatus according to claim 1 or 2, further comprising (1), wherein an expansion mechanism (EV) is connected downstream of the storage section (43). 4. A liquid sealing prevention passageway (27) connected between a liquid pipe between the storage section (43) and the expansion mechanism (EV) and a discharge pipe of the compressor (21). The refrigeration apparatus according to claim 3, wherein the liquid seal prevention passage (27) is configured as a one-way passage that allows refrigerant to flow from the liquid pipe side to the discharge pipe side. 5. A discharge pipe temperature sensor (Td), a condenser temperature sensor (Tc, Te), an evaporator temperature sensor (Te, Tc), and an output of each temperature sensor (Td, Tc, Te). The refrigeration apparatus according to any one of claims 1 to 4, further comprising control means (50) for controlling an opening degree of the expansion mechanism (EV) by using the control means. 6. The refrigeration apparatus according to claim 1, wherein the non-azeotropic refrigerant mixture is R407C.