JPS62158958A - Separation type heat pump system 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 a separate heat pump type air conditioner that can improve the operational reliability of the air conditioner with respect to the amount of refrigerant charged therein.

[Conventional technology]

FIG. 4 is a refrigerant circuit diagram of a conventional air conditioner shown in, for example, the specification of Utility Model Application No. 168072/1980. In this FIG. 4, 1 is a compressor, 2 is a four-way valve, and 3 is an outdoor heat exchanger. vessel, 4
5 is a capillary tube for decompression, 5 is an indoor heat exchanger, and 6 is an accumulator, which are successively connected by refrigerant piping to form a heat pump type refrigerant circuit.

Next, its operation will be explained. During cooling, the four-way valve 2 is in the position shown by the solid line in Figure 4, and the high-temperature, high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way valve 2 and enters the outdoor heat exchanger 3, where it exchanges heat with outdoor air. By replacing the refrigerant, the refrigerant is cooled while maintaining high pressure, condenses, becomes a high-pressure supercooled liquid refrigerant, and is depressurized by the decompression capillary tube 4 to become a low-pressure two-phase refrigerant.

This low-pressure two-phase refrigerant is heated by exchanging heat with indoor air in the indoor heat exchanger 5, evaporates, and becomes a highly dry two-phase refrigerant or superheated gas refrigerant at a low pressure. 2. The cycle of passing through the accumulator 6 and returning to the compressor 1 is repeated.

Also, during heating, the four-way valve 2 is at the position indicated by the broken line in Figure 4.
The high temperature and high pressure gas refrigerant discharged from the compressor 1 is passed through the four-way valve 2.
, an indoor heat exchanger 5 that operates as a condenser, a capillary tube 4 for pressure reduction, an outdoor heat exchanger 3 that operates as an evaporator, a four-way valve 2,
A heating cycle is constructed with the accumulator 6 and the compressor 1 exhibiting state changes similar to those during cooling in this order.

In the heat pump cycle described above, the decompression capillary tube 4 is installed in the indoor unit or the outdoor unit. For example, a further explanation will be given regarding the cycle refrigerant filling amount when installed in the outdoor unit.

As can be seen from the operation description of the cycle above, the state of the refrigerant in the refrigerant pipe between the decompression capillary tube 4 and the indoor heat exchanger 5 is in a low-pressure two-phase state during cooling, and its average specific weight is 0.
6 g/cJ, and during heating, it is a high-pressure supercooled liquid refrigerant, with an average specific weight of 1.2
g/c+a.

In addition, the specific weight of the refrigerant in the refrigerant pipe connecting the indoor heat exchanger 5 and the four-way valve 2 does not differ between cooling and heating. Therefore, when the length of the piping connecting the indoor unit and the outdoor unit changes, in order to achieve the same operating conditions during heating and cooling, the amount of refrigerant must be refilled or additionally charged based on the amount during heating.

In FIG. 5, the horizontal axis represents the connecting piping length between the indoor and outdoor units, and the vertical axis represents the required refrigerant filling amount.

It can be seen that the longer the pipe length, the greater the difference in the amount of refrigerant required during cooling and heating.

The above phenomenon also occurs when the decompression capillary tube 4 is installed in the indoor unit. However, the state inside the connecting pipe between indoor and outdoor units is a high-pressure supercooled liquid refrigerant during cooling, and a low-pressure two-phase refrigerant during heating, and the required refrigerant light @ amount when the pipe length changes is opposite to the above. The value becomes large during cooling.

In any case, as long as there is only one decompression capillary, there will be a difference in the amount of refrigerant required during cooling and heating, and this difference becomes larger as the length of the pipe connecting the indoor and outdoor units becomes longer.

[Problem that the invention seeks to solve]

Conventional air conditioners are configured as described above.
There is a difference in the amount of refrigerant required for cooling and heating, and this difference becomes larger as the length of the connecting piping between the indoor and outdoor units becomes longer. This difference is limited by the capacity of the accumulator that stores the difference as surplus refrigerant. If the piping length between the outside unit is limited or the length of the connecting piping between the indoor and outdoor units is long, a large amount of additional refrigerant must be filled on-site, and the accuracy of the additional refrigerant filling at that time is extremely poor. There were problems such as not operating with the correct required amount of refrigerant.

This invention was made to solve this problem, and there is no large difference in the amount of refrigerant required for cooling and heating, and even if the pipe length connecting the indoor and outdoor units is long, the amount of additional refrigerant charged can be increased. The purpose of the present invention is to provide a separate heat pump type air conditioner that can improve operational reliability with respect to the refrigerant charge amount, such as a small amount of refrigerant charge or no additional refrigerant charge amount, and that can extend the connection piping between indoor and outdoor units. do.

[Means for solving problems]

In the air conditioner according to the present invention, the outdoor unit is provided with a pressure reducing device during cooling, and the indoor unit is provided with a pressure reducing device for heating.

[For production]

In this invention, the indoor and outdoor units are connected by a decompression device immediately after the heat exchanger that operates as a condenser,
The state of the refrigerant in the pipe connecting the decompression device to the evaporator is set to a low-pressure, two-phase state with the same specific weight during both cooling and heating.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a separate heat pump type air conditioner according to the present invention will be described based on the drawings. FIG. 1 is a refrigerant circuit diagram of one embodiment. In FIG. 1, the same parts as in FIG. 4 are designated by the same reference numerals 31 and will be explained.

In Fig. 1, the compressor I, four-way valve 2, outdoor heat exchanger 3, indoor heat exchanger 5, and accumulator 6 are the same as in Fig. 4, and the following points differ from Fig. 4; This is the characteristic part of the example.

That is, the capillary tube 4 for pressure reduction in FIG. 4 is divided into a capillary tube 4a (liquid tube) for pressure reduction during cooling and a capillary tube 4b (gas tube) for pressure reduction during heating. These capillary tubes 4 for reducing pressure during cooling
a, capillary tubes 4b for pressure reduction during heating are check valves 7a, 7, respectively;
connected in parallel with b.

A parallel circuit of the capillary tube 4a for pressure reduction during cooling and the check valve 7a is arranged in the outdoor unit 8, and a parallel circuit of the capillary tube 4b for pressure reduction during heating and the check valve 7b is arranged in the indoor unit 9. There is.

The indoor unit 9 and the outdoor unit 8 are connected by indoor/outdoor unit connecting pipes Oa and IOb, respectively.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

During cooling, the four-way valve is in the position shown by the solid line in Figure 1, and the compressor 1
The high-temperature, high-pressure gas refrigerant discharged by passes through the four-way valve 2 and exchanges heat with outdoor air in the outdoor heat exchanger 3.
It is cooled, condensed, becomes a supercooled liquid refrigerant while maintaining high pressure, and becomes a low-pressure two-phase state refrigerant by the capillary tube 4a for pressure reduction during cooling in the outdoor unit 8.

This low-pressure two-phase refrigerant is connected to the indoor/outdoor unit connecting pipe 1.
0a to the indoor unit 9, passes through the check valve 7b, reaches the indoor heat exchanger 5, and exchanges heat with indoor air.
The refrigerant is heated at a low pressure, evaporates, becomes a highly dry two-phase refrigerant or hot water gas refrigerant, and returns to the compressor 1 via the indoor/outdoor unit connecting pipe 10b, the four-way valve 2, and the accumulator 6, and repeats the cycle.

During heating, the four-way valve 2 is located at the position indicated by the broken line in Figure 1, and the high-temperature, high-pressure gas refrigerant discharged by the compressor 1 is transferred to the four-way valve 2,
It exchanges heat with the indoor/outdoor unit connecting pipe 10b and the indoor heat exchanger 5 that operates as a condenser, becoming a high-pressure supercooled liquid refrigerant, and is depressurized by the capillary tube 4b for pressure reduction during heating in the indoor unit 9, resulting in a low-pressure two-phase state. It becomes a refrigerant, reaches the outdoor unit 8 from the indoor/outdoor unit connecting pipe 10a, exchanges heat with the outdoor heat exchanger 3 that operates as an evaporator from the check valve 7a, and becomes a highly dry two-phase refrigerant or superheated gas, The cycle of returning to compression 1a1 via four-way valve 2 and accumulator 6 is repeated.

Therefore, a low-pressure two-phase refrigerant flows through the indoor/outdoor unit connecting pipe 10a during both cooling and heating, and its average specific weight exhibits approximately the same value (0.6 to 0.7 g/cJ).

Further, a refrigerant in a gas state or in a two-phase state with a high degree of dryness flows through the indoor/outdoor unit connecting pipe 10b. Therefore, the required refrigerant filling amount shows almost the same value during both cooling and heating, and even if the length of the indoor/outdoor unit connecting pipe becomes longer, there is no difference in the required refrigerant filling amount.

In FIG. 2, the horizontal axis shows the length of the pipe connecting the indoor and outdoor units, and the vertical axis shows the required refrigerant filling amount. In order to perform proper operation when the length of the indoor/outdoor unit connection piping changes, all you need to do is to refill the refrigerant as shown in Figure 2.The additional amount is the same for both cooling and heating, and the amount of refrigerant required in the conventional example is 2. It is possible to reduce the time during adjustment and improve the accuracy of the refrigerant charging amount. Also,
The generation of surplus refrigerant is reduced.

In the above embodiment, a throttling mechanism in which the capillary tube 4a for depressurization during cooling and the check valve 7a are connected in parallel is installed in the outdoor unit 8, and a capillary tube 4b for depressurization during heating and the check valve 7b are connected in parallel in the indoor unit 8. The capillary tube 4b for pressure reduction during heating and the capillary tube 4b for pressure reduction during cooling were provided.
By adjusting the strength of the throttle a, the throttle action in the chamber can be performed by the sum of the capillary tubes 4b and 4a, and the throttle mechanism in the outdoor unit 8, excluding the check valve 7a, can be used as shown in FIG. The same effect can be obtained even if the capillary tube 4a is used only for reducing the pressure during cooling.

In addition, in the above embodiment, the amount of refrigerant charged is adjusted when the length of the indoor/outdoor unit connecting pipe changes, but even if the unit is filled with the required maximum amount of refrigerant, the length of the indoor/outdoor unit connecting pipe changes. The same effect can be obtained even if the adjustment of the amount of refrigerant is not required.

〔Effect of the invention〕

As explained above, in this invention, the throttling mechanism is configured so that even if the length of the pipe connecting the indoor and outdoor units changes, the amount of refrigerant charged during cooling and heating is the same. By reducing the amount of refrigerant to 2, it is possible to ensure operation with an appropriate amount of refrigerant, resulting in a highly reliable air conditioner.

[Brief explanation of drawings]

Fig. 1 is a refrigerant circuit diagram of a separate heat pump type air conditioner according to the present invention, Fig. 2 is a diagram showing the relationship between indoor and outdoor unit piping lengths and required refrigerant charging amount of the above-mentioned separate type heat pump type air conditioner, and Fig. 3 The figure is a refrigerant circuit diagram of another embodiment of the separate heat pump type air conditioner of the present invention, Figure 4 is a refrigerant circuit diagram of a conventional air conditioner, and Figure 5 is a conventional indoor/outdoor unit piping of an air conditioner. FIG. 3 is a diagram showing the relationship between the length and the required refrigerant filling amount. 1...Compressor, 2...Four-way valve, 3...Outdoor heat exchanger, 4a...Capillary tube for pressure reduction during cooling, 4b...Capillary tube for pressure reduction during heating, 5...Indoor heat exchanger 6...Accumulator, 7a, 7b...Check valve, 8...Outdoor unit, 9...Indoor unit, 10a, 10b...Indoor/outdoor unit connection piping, Note that the same symbols in the drawings Indicates the same or equivalent part. Agent Masuo Oiwa (and 2 others)
Name) KoN Yuchenshi Renyu Cup -- Bazai 3 Figure! Figure 4 Figure 5 ↑ Required 2,7・When heating・1 Cooling medium −2−

Claims (3)

[Claims] (1) Compressor, four-way valve, outdoor heat exchanger, capillary tube for pressure reduction,
In an air conditioner constituted by a refrigerant circuit in which an indoor heat exchanger and an accumulator are sequentially connected by refrigerant piping, a pressure reducing device for cooling is provided in an outdoor unit consisting of the compressor, a four-way valve, and an outdoor heat exchanger, and for heating. A separate heat pump type air conditioner characterized in that a pressure reducing device is provided in an indoor unit composed of an indoor heat exchanger. (2) The separate heat pump type air conditioner according to claim 1, further comprising a throttle mechanism in which a capillary tube and a check valve are connected in parallel as a pressure reducing device in the indoor/outdoor unit. (3) Fill the outdoor unit with the required maximum amount of refrigerant,
2. The separate heat pump type air conditioner according to claim 1, wherein the required refrigerant charging amount remains unchanged even if the length of the indoor/outdoor unit connecting pipe connecting the indoor unit and the outdoor unit changes.