JP3281438B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using a mixed refrigerant as a refrigerant.

[0002]

2. Description of the Related Art Generally, in a heat pump type air conditioner, for example, as shown in FIG.
, An indoor heat exchanger 103, a decompression device 105, and an outdoor heat exchanger 107.

In the cooling mode, the four-way valve 109 is switched so that the indoor heat exchanger 103 is used as an evaporator and the outdoor heat exchanger 107 is used as a condenser. The refrigerant discharged from the compressor 101 is As shown by the dotted arrow, the outdoor heat exchanger 107 → the decompression device 105 → the indoor heat exchanger 10
After passing through 3, the refrigerant that has completed its work repeats a refrigeration cycle returning to the compressor 101 again.

[0004] In the heating mode, the indoor heat exchanger 103 is used as a condenser and the outdoor heat exchanger 107 is used as an evaporator. The refrigerant discharged from the compressor 101 is subjected to indoor heat exchange as shown by a solid arrow. Vessel 103 → decompression device 105
→ The refrigerant that has completed work after passing through the outdoor heat exchanger 107 returns to the compressor 101 again, so that a cooling mode and a heating mode can be respectively obtained.

[0005]

As described above, indoor and indoor
By using the outdoor heat exchangers 103 and 107 as an evaporator or a condenser, respectively, a cooling mode and a heating mode can be obtained. In this case, when a mixed refrigerant composed of a low-boiling refrigerant that evaporates easily and a high-boiling refrigerant that hardly evaporates is used instead of a single refrigerant, when the heat exchanger acts as an evaporator, the evaporator is evaporated at the outlet side of the heat exchanger. A gas-liquid two-phase state having a high liquid ratio of the high-boiling-point refrigerant, which is difficult to generate, is generated, and the flow resistance of the refrigerant is increased. As a result, the suction pressure of the compressor is reduced, and the performance of the compressor is reduced. At the same time, at the inlet side of the heat exchanger, the pressure in the pipe relatively increases due to the effect of flow resistance,
Performance and other factors, such as hindering the evaporation of liquid refrigerant and reducing the amount of heat exchange
This causes a reduction in efficiency.

On the other hand, when the heat exchanger acts as a condenser, a gas-liquid two-phase state having a high gas ratio of the low boiling point refrigerant which is hardly condensed is generated at the outlet side of the heat exchanger, and the heat exchange pipe and the uncondensed refrigerant are not condensed. As a result of preventing the contact of the gaseous refrigerant, the heat transfer coefficient of the heat exchange pipe is reduced, which causes a decrease in the amount of heat exchange, which causes a decrease in performance and efficiency.

Accordingly, an object of the present invention is to provide an air conditioner capable of improving the performance and the performance efficiency in a cooling mode and a heating mode using a mixed refrigerant.

[0008]

In order to achieve the above object, the present invention comprises a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger. An air conditioner using a mixed refrigerant that uses an indoor heat exchanger as an evaporator and an outdoor heat exchanger as a condenser in a cooling mode while using an exchanger as a condenser and an outdoor heat exchanger as an evaporator. in, the outdoor heat exchanger, so as to form between the fins for cooling the tube through which the refrigerant flows, in the middle of the tube, the liquid reservoir tank for separating the gas component and the liquid component of the refrigerant is provided in the liquid reservoir tank
Are operated by the level of the liquid in this tank.
A funnel valve is provided, and in the heating mode,
The separated gas component is supplied to the compressor via the one float valve.
To the suction side of the
The liquid component separated in the storage tank is passed through the other float valve.
The pressure is then sent to the inflow side of the decompression device .

[0009]

[0010]

According to this air conditioner, in the heating operation, the mixed refrigerant repeats a cycle of passing through the compressor, the indoor heat exchanger, the decompression device, and the outdoor heat exchanger and returning to the compressor again.
At this time, in the indoor heat exchanger acting as a condenser,
The air passing through the fins undergoes heat exchange, and is sent out as warm air toward the room.

Next, in the outdoor heat exchanger functioning as an evaporator, after the evaporation mainly composed of a low-boiling-point refrigerant in the first half of the heat exchanger, it is sent into a liquid storage tank, where the liquid component and gas are removed. Separated into components and stored. The separated and stored gas components are sent out to the suction side of the compressor.

On the other hand, in the latter half of the outdoor heat exchanger, the non-evaporated liquid refrigerant mainly composed of the high-boiling refrigerant sent from the former half has a very small gas component ratio.
Due to a decrease in the volume flow rate and a decrease in the flow velocity in the pipe, the flow resistance in the pipe is reduced, and the reduction in the suction pressure of the compressor is reduced. At the same time, the pressure in the pipe on the inlet side becomes relatively low, the evaporation of the liquid refrigerant is promoted, and the heat exchange amount increases.

Next, when the cooling operation is started, the indoor heat exchanger functions as an evaporator and the outdoor heat exchanger functions as a condenser.
That is, the refrigerant gas is sucked and compressed by the compressor, and is sent out at high temperature and high pressure. The high temperature and high pressure gas enters a condenser (heat exchanger). At this time, the refrigerant gas is liquefied by depriving the latent heat of condensation by the air passing through the fins.

The liquefied refrigerant flows to the decompression device, where the high-pressure refrigerant expands rapidly to form a low-temperature, low-pressure mist.
Next, it flows into an evaporator (heat exchanger), takes the latent heat of evaporation from the surrounding air through fins, cools the air to cool air,
Sent to the room. The refrigerant changes from mist to gaseous here,
It flows again to the compressor. Cooling is performed by repeating this cycle.

In this refrigeration cycle, after the condensation mainly of the high-boiling refrigerant is performed in the first half of the outdoor heat exchanger, it is sent into the liquid storage tank, where it is separated and stored into the liquid component and the gas component. You. The separated and stored liquid components are sent out to the suction side of the decompression device.

[0016] On the other hand, in the second half portion of the outdoor heat exchanger, from the first half, since the ratio of the gas components is large refrigerant fed, Chu without gas refrigerant being obstructed by the liquid refrigerant
The contact is facilitated and the condensation is promoted. These cooling operations
The liquid storage tank is installed outside the
Is installed in the outdoor heat exchanger,
Eliminating countermeasures for the annoying refrigerant noise is eliminated. Also, indoor and outdoor
Operating environment such as temperature and humidity conditions, and air flow rate of heat exchanger
Of the refrigerant mixture in the liquid storage tank
The composition ratio of the component and the liquid component changes, but the
Is a float that operates depending on the level of the liquid in this tank.
Because the valve is provided, the flow is
Gas valve or liquid component of the mixed refrigerant
Control the flow rate of gas, ensuring that the appropriate gas components and liquid
Can be separated into minutes. As a result, changes in operating environment conditions
However, efficient operation can be ensured.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 shows a heat pump type air conditioner in which a non-azeotropic mixed refrigerant in which a high boiling point refrigerant and a low boiling point refrigerant are mixed is enclosed, 1 is a compressor having a suction cup 3, and 5 is a four-way compressor. Valve, 7 is an indoor heat exchanger, 9 is a decompression device,
Numeral 11 denotes an outdoor heat exchanger, which is connected and connected via a refrigerant pipe 13.

The compressor 1 functions to discharge the gaseous non-azeotropic refrigerant from the suction cup 3 as a high-temperature, high-pressure refrigerant gas.

The four-way valve 5 switches the compressor 1 by switching operation.
From the indoor heat exchanger 7 or the outdoor heat exchanger 11
In the drawing, the refrigerant gas discharged from the compressor 1 is set to be sent to the indoor heat exchanger 7 side.

The indoor heat exchanger 7 is used as an evaporator during cooling and as a condenser during heating.

In the indoor heat exchanger 7 used as an evaporator, the refrigerant gas sent as a low-temperature and low-pressure mist from the pressure reducing device 9 is supplied to the heat exchanger 7 by the indoor blower 15.
Evaporate by the air passing through the fins to become gaseous and take away the latent heat of evaporation from the surrounding air through the fins,
It functions to cool the air into cool air, and the cool air is sent indoors by the indoor blower 15.

In the indoor heat exchanger 7 used as a condenser, the refrigerant gas sent from the compressor 1 in the form of a high-temperature and high-pressure gas passes through the fins of the heat exchanger 15 by the indoor blower 15. The latent air of heat is deprived of latent heat of condensation to form a mist and functions to give heat to the air when passing through the fins to generate hot air. The hot air is sent to the room by the indoor blower 15.

The decompression device 9 functions to make the refrigerant into a low-temperature, low-pressure mist and to adjust the flow rate of the refrigerant according to operating conditions such as a heat load by a command signal from a refrigerant temperature detector (not shown). I do.

The outdoor heat exchanger 11 is used as an evaporator at the time of heating and as a condenser at the time of cooling, respectively. The first heat exchanger 16 as a first half and the second heat as a second half. A liquid storage tank 19 is provided between the first and second heat exchange units 16 and 17.

The first and second heat exchange sections 16 and 17 and the liquid storage tank 19 are connected and connected via a refrigerant pipe 13, and the first heat exchanger is connected to the first heat exchanger from the upstream side in the refrigerant flow direction in the heating mode. 16, a liquid reservoir tank 19, and a second heat exchanger 17 are arranged in this order.

The first and second heat exchanging sections 16 and 17 each comprise a tube 21 through which a refrigerant flows and fins 23 for cooling. When used as an evaporator, the refrigerant gas fed in a mist state is The air passing through the fins 23 evaporates and becomes gaseous, and the air passing through the fins 23 is discharged to the outside by the outdoor blower 19.

Further, when used as a condenser, the refrigerant gas which is sent in the form of a high-temperature and high-pressure gas is deprived of the latent heat of condensation by the air passing through the fins 23 by the outdoor blower 25 and becomes mist-like. The air that has passed through the fins 23 is discharged outside by the outdoor blower 25.

The liquid storage tank 19 separates and stores the refrigerant into a liquid component and a gas component. As shown in FIG. 2, the liquid component is separated by its own weight into a lower portion and the light gas component into an upper portion. You. The separated liquid component is sent to a refrigerant pipe 13 that connects the first heat exchange unit 16 and the pressure reducing device 9 via a first bypass circuit 29 having a check valve 27.

The gas component is sent through a second bypass circuit 33 provided with a check valve 31 to a refrigerant pipe 13 connecting the second heat exchange section 17 and the four-way valve 5.

The check valve 27 provided in the first bypass circuit 29 functions to flow only in one direction from the liquid storage tank 19 side to the pressure reducing device 9 side. In this case, the check valve 27
Instead, a liquid flow control valve capable of controlling the first bypass circuit 29 to an optimum value according to the operating conditions may be used.

The check valve 31 provided in the second bypass circuit 33 functions so as to flow only in one direction from the liquid storage tank 19 side to the four-way valve 5 side. In this case, a gas flow control valve capable of controlling the second bypass circuit 33 to an optimum value according to the operating conditions may be used instead of the check valve 31.

On the other hand, the first and second bypass circuits 29 and 33
In the reservoir tank 19, the float valves 35, 3
5 are provided, and the float valve 35 provided in the first bypass circuit 29 shuts off the bypass circuit when the liquid component becomes low, as indicated by the dashed line, and the gas component becomes the first component.
It functions to prevent the flow into the bypass circuit 29.

The float valve 35 provided in the second bypass circuit 33 shuts off the bypass circuit as indicated by a dashed line when the liquid component increases and the liquid level rises, and the liquid component is removed from the second bypass circuit 33. It functions to prevent it from flowing into 33.

According to such an air conditioner, for example, during heating using the indoor heat exchanger 7 as a condenser and the outdoor heat exchanger 11 as an evaporator, the refrigerant flows from the compressor 1 → the indoor heat exchanger 7 → The heating cycle that returns to the compressor 1 through the decompression device 9 and the outdoor heat exchanger 11 is repeated. During this operation, in the indoor heat exchanger 7, the air when passing through the fins 23 is given heat, is turned into warm air by the indoor blower 15, and is sent out indoors.

On the other hand, in the outdoor heat exchanger 11, the refrigerant acts as an evaporator, and the refrigerant is evaporated in the first heat exchange section 16, mainly composed of a low-boiling-point refrigerant.
And is separated and stored in a liquid component and a gas component. The separated and stored gas component is supplied to the second bypass circuit 33.
Is discharged to the suction side of the compressor.

On the other hand, in the second heat exchanger 17,
The non-evaporated liquid refrigerant mainly containing the high boiling point refrigerant sent from the heat exchanger 16 has a very small gas component ratio, so that the volume flow rate decreases and the flow velocity in the tube 21 decreases. It is less likely that the resistance is reduced and the suction pressure of the compressor 1 is reduced. At the same time, since the tube pressure on the inlet side is relatively low, the evaporation of the liquid refrigerant is promoted, the heat exchange amount is increased, and an efficient heating operation can be performed.

Next, in the cooling operation, the indoor heat exchanger 7 functions as an evaporator, and the outdoor heat exchanger 11 functions as a condenser. That is, the refrigerant gas is sucked and compressed by the compressor 1 and sent out at a high temperature and a high pressure. This high-temperature high-pressure gas enters the condenser (heat exchanger 11). At this time, the refrigerant gas is liquefied by deprived of the latent heat of condensation by the air passing through the fins 23.

The liquefied refrigerant gas flows to the pressure reducing device 9,
Here, the high-pressure gas expands rapidly and becomes a low-temperature, low-pressure mist. Next, it flows into an evaporator (heat exchanger 7), takes latent heat of evaporation from the surrounding air through fins, cools the air to cool air, and sends it to the room. Here, the refrigerant gas changes from a mist state to a gas state, and flows into the compressor 1 again. Cooling is performed by repeating this cycle.

At the time of the refrigeration cycle, after the condensation mainly of the high-boiling refrigerant is performed in the second heat exchanger 17, it is sent into the liquid storage tank 19, where it is separated and stored into a liquid component and a gas component. Is done. The separated and stored liquid component is the first
Since the gas refrigerant in the second heat exchanger 17 is sent to the pressure reducing device 9 via the bypass circuit 29, the gas refrigerant in the second heat exchanger 17 contacts the wall surface of the tube 21 without being disturbed by the liquid refrigerant so that efficient condensation is performed. Become.

[0041]

As described above, according to the air conditioner of the present invention, the mixed refrigerant can be separated and stored into the liquid component and the gas component in accordance with the operation mode. The ability can be greatly improved. Ma
In addition, since the liquid storage tank is provided in the outdoor heat exchanger,
It is necessary to take measures against harsh refrigerant noise flowing in the tank.
No need. In addition, the choice of cooling or heating
Temperature and humidity conditions inside and outside the room,
Changes in operating environment conditions, such as
Of the gas and liquid components of the mixed refrigerant in the liquid storage tank
Even if the ratio changes, the liquid level in the reservoir tank will
The change of the composition ratio by the float valve which operates more
The float valve always follows the gas component of the mixed refrigerant.
Alternatively, the flow rate of liquid components can be controlled appropriately and always
Gas and liquid components. The driving environment
Efficient operation can be ensured even when conditions change.

[Brief description of the drawings]

FIG. 1 is a piping diagram of an air conditioner according to the present invention.

FIG. 2 is a schematic sectional view of a liquid storage tank.

FIG. 3 is a schematic diagram of first and second heat exchange units.

FIG. 4 is a piping diagram similar to FIG. 1 using a conventional single refrigerant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 7 Outdoor heat exchanger 9 Decompression device 11 Indoor heat exchanger 19 Liquid storage tank 21 Tube 23 Fin

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takayoshi Iwanaga 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Pref. Toshiba Corporation Living Space Systems Research Laboratory (72) Inventor Tetsuji Yamashita 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Toshiba Living Space System Technology Research Institute (72) Inventor Koichi Goto 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Living Space System Technology Research Laboratory (56) References JP-A-57-41559 (JP, A) Practical application Hei 2-24251 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 39/00 F25B 1/00 385 F25B 5/00 309 F25B 13/00

Claims (1)

(57) [Claims] 1. A compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger.
While using the indoor heat exchanger as a condenser and the outdoor heat exchanger as an evaporator, in the cooling mode, air using mixed refrigerant using the indoor heat exchanger as an evaporator and the outdoor heat exchanger as a condenser in conditioner, the outdoor heat exchanger, so as to form between the fins for cooling the tube through which the refrigerant flows, in the middle of the tube is provided with a liquid reservoir tank for separating the gas component and the liquid component of the refrigerant, the liquid
The sump tank operates depending on the level of the liquid in the tank.
Two float valves are provided, and in the heating mode, the liquid reservoir is provided.
The gas component separated in the tank is passed through the one float valve.
And send it to the suction side of the compressor.
The liquid component separated in the liquid storage tank is
An air conditioner characterized in that the air is sent to an inflow side of a pressure reducing device via a heat valve .