JPS63306364A - Air-conditioning changeover type air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an air conditioner that uses a heat pump for both heating and cooling purposes.

[Prior Art] A heat pump type air conditioner usually has the following characteristics as shown in Fig. 4.
A refrigerant cycle is composed of a compressor 1, a four-way switching valve 2 as a refrigerant circuit switching means, an outdoor heat exchanger 3, a liquid receiver 4, and an indoor heat exchanger 5.

Note that 6a and 6b are expansion valves, and 7.7 is a check valve.

During heating operation, as shown by solid arrow A, the refrigerant discharged from the compressor 1 is condensed in the indoor heat exchanger 5 and then flows into the liquid receiver 4, where it is separated into gas and liquid. The liquid refrigerant is adiabatically expanded by the expansion valve 6a and enters the outdoor heat exchanger 3,
The outdoor heat exchanger 3 absorbs heat from the outside air, evaporates it, and returns to the compressor 1.

On the other hand, during cooling operation, as shown by the broken line arrow B, the refrigerant discharged from the compressor 1 is condensed in the outdoor heat exchanger 3, and then separated into gas and liquid in the liquid receiver 4, and the liquid refrigerant is insulated by the expansion valve 6b. It expands and enters the indoor heat exchanger 5, where it absorbs heat from the indoor air, evaporates, and returns to the compressor 1.

However, when performing a cooling operation using such a refrigerant cycle, the refrigerant at the inlet of the expansion valve 6b becomes a saturated liquid due to the presence of the liquid receiver 4, so there is a problem that the refrigerant capacity cannot be increased.

As a means to increase the refrigerating capacity during cooling operation, the fifth
In the cooling-only cycle shown in the figure, one in which a supercooler 10 is provided downstream of the liquid receiver 4 has been proposed. According to this, the refrigerant is supercooled before entering the expansion valve 6b, so that the refrigerating capacity is improved.

[Problems to be Solved by the Invention] However, the cycle shown in FIG. 5 above is dedicated to the cooling operation cycle, and when such a supercooler 10 is used in a heat pump air conditioner as shown in FIG. It is possible to increase the refrigerating capacity, that is, the amount of heat absorbed, by the outdoor heat exchanger 3 during cooling operation, but during reverse cycle heating operation, the heat is radiated by the supercooler 10 installed outdoors. There is no effect on increasing the amount of heat dissipated by the indoor heat exchanger 5, that is, the heating capacity, and there is a problem that the indoor heat exchanger 5 becomes an unnecessary device.

The present invention aims to provide a cooling/heating switching type air conditioner that can improve the performance during both cooling and heating, and prevents problems such as a supercooler becoming unnecessary equipment.

[Means for Solving the Problems] The present invention provides a second outdoor heat exchanger and a second indoor heat exchanger as a supercooler in which the flow of refrigerant can be switched by a switching means downstream of a liquid receiver. During cooling operation, the second indoor heat exchanger serves as a supercooler and the second outdoor heat exchanger serves as an auxiliary evaporator, and during heating operation, the second outdoor heat exchanger serves as a supercooler. The second indoor heat exchanger also functions as an auxiliary evaporator.

[Function] According to the present invention, the refrigerant at the inlet of each expansion valve becomes supercooled during both cooling and heating, so the refrigeration effect is increased and both cooling and heating capacities are improved. Moreover, the supercooler, which was conventionally an unnecessary device during heating operation, effectively functions as an evaporator, contributing to improved performance during heating.

[Embodiment] The present invention will be described below based on an embodiment shown in FIGS. 1 and 2.

In this embodiment, parts that are the same as those in the conventional example shown in FIG. 4 are given the same numbers and their explanations will be omitted.

On the downstream side of the liquid receiver 4, a three-way switching valve 20a,
20b to the second outdoor heat exchanger 21 and the second
An indoor heat exchanger 22 is connected.

The downstream side of the second outdoor heat exchanger 21 is connected to the downstream side of the first outdoor heat exchanger 3 via a check valve 23a, and is also connected to the expansion valve 6b.

The downstream side of the second indoor heat exchanger 22 is connected to the downstream side of the first indoor heat exchanger 5 via a check valve 23b, and is also connected to the expansion valve 6a.

One of the three-way switching valves 20a opens on the liquid receiver 4 side during cooling, and opens on the expansion valve 6a side during heating.

The other three-way switching valve 20b opens toward the expansion valve 6b during cooling, and opens toward the liquid receiver 4 during heating.

The operation of the embodiment with such a configuration will be explained.

During heating operation, the refrigerant discharged from the compressor 1 enters the first indoor heat exchanger 5 as shown by the solid arrow A, condenses there, and then enters the liquid receiver 4 where gas and liquid are separated. Ru.

The liquid refrigerant is transferred to the second indoor heat exchanger 2 via the three-way switching valve 20b.
2 and is supercooled.

This second indoor heat exchanger 22 thus performs the function of a supercooler.

The refrigerant supercooled in the second indoor heat exchanger 22 reaches the expansion valve 6a, where it undergoes adiabatic expansion and is then separated into the first outdoor heat exchanger 3 and the second outdoor heat exchanger 21. The air flows in parallel, absorbs heat from the outside air by these outdoor heat exchangers 3 and 21, evaporates, and returns to the compressor 1, respectively.

Therefore, the second outdoor heat exchanger 21 serves as an auxiliary evaporator.

On the other hand, during cooling operation, the four-way switching valve 2 is switched, and the three-way switching valves 20a and 20b are also switched, and the refrigerant discharged from the compressor 1 is transferred to the first outdoor heat source as shown by the broken line arrow B. It enters exchanger 3 where it is condensed. Thereafter, it flows into the liquid receiver 4 and the gas and liquid are separated. The liquid refrigerant passes through the three-way switching valve 6a, flows into the second outdoor heat exchanger 21, and is supercooled.

Therefore, in this case, the second outdoor heat exchanger 21 functions as a supercooler.

The refrigerant supercooled in the second outdoor heat exchanger 21 reaches the expansion valve 6b, where it expands adiabatically. Thereafter, the refrigerant branches into the first indoor heat exchanger 5 and the second indoor heat exchanger 22, and in each of these indoor heat exchangers 5 and 22, the refrigerant takes heat from the indoor air and evaporates. . The refrigerant evaporated in each of these indoor heat exchangers 5° 22 returns to the compressor 1.

Therefore, in this case, the second indoor heat exchanger 22 becomes an auxiliary evaporator.

According to such an air conditioner, the expansion valve 6a.

Since the refrigerant on the inlet side of 6b is supercooled by each of the second heat exchangers 22 and 21, the refrigerating capacity is increased on the evaporation side. Therefore, during the heating operation, the amount of heat absorbed from the outside air increases and the heating capacity is improved, and during the cooling operation, heat is taken away from the indoor air, so the cooling capacity is improved.

In addition, when one of the second heat exchangers is functioning as a supercooler, the other second heat exchanger is functioning as an auxiliary evaporator, so not only is there no unnecessary equipment, but heating, Contributes to improving cooling capacity.

Therefore, as shown in the cycle characteristic diagram of FIG. 2, the cycle of the present invention (solid line) is different from the conventional type (solid line) shown in FIG.
An improvement in ability is recognized compared to the dashed line).

In the embodiment shown in FIG. 1, a three-way switching valve 20a is provided upstream of the second outdoor heat exchanger 21 and the second indoor heat exchanger 22.
, 20b are provided, however, electromagnetic switching valves 30a, 30b may be used as in another embodiment shown in FIG.

Furthermore, instead of the four-way switching valve 2, a refrigerant circuit switching means combined with a solenoid valve may be used.

Furthermore, the first outdoor heat exchanger 3 and the second outdoor heat exchanger 21. The first indoor heat exchanger 5 and the second indoor heat exchanger 22 may be connected to each other to form an integral structure, such as by sharing fins.

[Effects of the Invention] As explained above, according to the present invention, the refrigerant at the inlet of the expansion valve becomes supercooled during both cooling and heating, so the refrigeration effect is increased and both cooling and heating capacities are improved.

Moreover, the supercooler, which was previously an unnecessary device during heating,
The auxiliary evaporator becomes an auxiliary evaporator, and the auxiliary evaporator is present during both cooling and heating operation, so this also applies to cooling and heating operations.
Contributes to improving heating capacity.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a cycle configuration diagram, FIG. 2 is a characteristic diagram, and FIG. 3 is a cycle configuration diagram showing another embodiment of the present invention. 4 to 6 are respectively different conventional cycle configuration diagrams. DESCRIPTION OF SYMBOLS 1...Compressor, 2...4-way switching valve, 3...1st outdoor heat exchanger, 4...Liquid receiver, 5...1st indoor heat exchanger, 6a, 6b= Expansion valve, 20a, 20b-3-way switching valve, 21...second outdoor heat exchanger, 22...second
Indoor heat exchanger. Applicant's agent Patent attorney Suzue Takehiko Engruch 1 Figure 2 Figure 3

Claims (1)

[Claims] In an air conditioner in which a refrigerant cycle is configured by a compressor, a refrigerant circuit switching means, an outdoor heat exchanger, an indoor heat exchanger, a liquid receiver, and an expansion valve, and the refrigerant circuit switching means can switch between cooling operation and heating operation. A second outdoor heat exchanger and a second indoor heat exchanger are provided downstream of the liquid receiver, and the flow of the refrigerant is switched through another switching means, and the second outdoor heat exchanger is switched during cooling operation. While functioning as a supercooler, the second indoor heat exchanger also functions as an auxiliary evaporator, and during heating operation, the second indoor heat exchanger functions as a supercooler and the second outdoor heat exchanger serves as an auxiliary evaporator. A heating/cooling switching type air conditioner characterized by functioning as an evaporator.