JPS59210274A - 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 The present invention relates to a refrigeration cycle and a control device for a separate air conditioner, and relates to cooling operation, heating operation, and capacity control when the refrigerant piping connecting the indoor and outdoor units is long. It provides highly efficient and reliable operation in both cases of defrosting, and prevents refrigeration oil and refrigerant from entering the compressor discharge valve side when the air conditioner is stopped, and prevents valve damage when the compressor is started. This invention relates to a refrigeration cycle and a control device that aim to prevent this.

A conventional device of this type is shown in FIG.

During cooling operation, high-temperature, high-pressure refrigerant and refrigerating machine oil discharged from the compressor 1 pass through the four-way valve 2 and reach the outdoor heat exchanger 3.
It exchanges heat with the high-temperature, high-pressure liquid, passes through the distributor 4, is depressurized at the expansion valve 5, passes through the connecting pipe 6, evaporates in the indoor heat exchanger 7, passes through the connecting pipe 8, and then passes through the four-way valve 2,
A circulation cycle is formed in which the air is sucked into the compressor 1 again through the accumulator 9. Therefore, especially when the compressor 1 is started, the refrigerant that has been trapped in the refrigerating machine oil causes foaming, and a large amount of refrigerating machine oil is discharged.Also, during continuous operation, the refrigerating machine oil is constantly discharged, and the discharged refrigerating machine oil is It circulates through the cycle and returns to the suction side of the compressor 1, but if the connecting pipes 6 and 8 are particularly long, it will take time for the discharged refrigeration oil to circulate and return to the compressor. If there is not enough refrigerating machine oil in the refrigerating machine 1, the compressor will suffer from poor lubrication and the sliding parts will seize. In addition, when capacity control is performed, the amount of refrigerant circulating during low-load operation decreases, and the speed of refrigerant flowing through the pipes decreases, resulting in poor return of refrigerating machine oil, which causes a failure in the compressor 1. It had drawbacks. The same goes for heating.

During defrosting, the high temperature, high pressure refrigerant discharged from the compressor 1 passes through the four-way valve 2 and reaches the outdoor individual exchanger 3.
Defrost and exchange heat with high temperature, high pressure liquid.
After passing through the distributor 4, the pressure is reduced again by the expansion valve 5, and the circulation is sucked into the compressor 1 again through the (3) indoor heat exchanger 7, connection piping 8, 4-way valve 2, and accumulator 9. Forming a cycle, the indoor heat exchanger 7 side fan (not shown)
When I run it, it blows out cold air, so I try to stop it. Therefore, the low-temperature, low-pressure two-phase flow refrigerant whose pressure has been reduced by the expansion valve 5 is not heat-exchanged by the indoor heat exchanger T, so the pressure of the low-pressure gas is reduced to 9, and the refrigerant enters the accumulator 9 as it is, and the liquid Since the refrigerant accumulates, the amount of refrigerant circulated is reduced, and the input to the compressor is also reduced, which has the drawback of prolonging the defrost time.

In addition, when the air conditioner is stopped, the refrigerant that had accumulated in the connecting pipe 8 returns to the discharge pipe of the compressor due to its own weight, filling the discharge valve port of the pressure l# machine, and when the compressor is started, the refrigerant that has accumulated in the connecting pipe 8 returns to the discharge pipe of the compressor. (not shown) had the disadvantage of causing damage.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional technology.A check valve and an oil separator are provided in this order between the discharge side of the compressor and the four-way valve. Via
By providing a bypass path to the accumulator and returning refrigerating machine oil to the accumulator (4), compressor failure due to lack of refrigerating machine oil can be prevented, and by returning part of the discharged gas during defrost to the accumulator, low pressure can be achieved. By increasing the pressure and sending a highly concentrated refrigerant with a small specific volume into the compressor, the defrosting capacity can be greatly increased, and defrosting can be completed in a short time, and when the air conditioner is stopped. Even if the refrigerant and refrigeration machine oil that had accumulated in the discharge piping system return to the discharge side of the compressor 1 due to their own weight and pressure, they will be accumulated in the oil separator and discharged from the compressor by the check valve. The object of the present invention is to provide an air conditioner that prevents the compressor from entering the interior of the compressor and prevents the compressor valve from being damaged when the compressor is started.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, the same or equivalent parts as in FIG. 1 are indicated by the same reference numerals. In Fig. 2, 10 is an oil separator, 11
12 is a solenoid valve, and 13 is a check valve. That is, as shown in FIG. 2, a check valve 13 and an oil separator 10 are arranged in this order between the discharge side of the compressor 1 and the four-way valve 2, and a check valve 13 and an oil separator 10 are arranged in this order. A bypass path 11 is provided to reach the accumulator 9 via the compressor 1.
A check valve 13 is provided between the discharge side of the oil separator 10 and the oil separator 10, and is closed when the pressures before and after are the same.

The present invention will be described in detail with the above configuration.

In Figure 2, the solid arrows indicate the flow of refrigerant during cooling and defrost operation, the dashed arrows indicate the flow of refrigerant during heating, and the dashed line indicates the flow of refrigerant and refrigerating machine oil in the bypass path. It represents.

During cooling, the high-temperature, high-pressure refrigerant and refrigerating machine oil discharged from the compressor 1 pass through the check valve 13, and the refrigerating machine oil is separated from the top of the oil separator 10, and accumulates at the bottom of the oil separator 10. ing. The refrigerant separated from the refrigeration oil comes out of the upper part of the oil separator 10, reaches the four-way valve 2 and the outdoor heat exchanger 3, where it exchanges heat and becomes a high-temperature, high-pressure liquid 9. It expands through the distributor 4. The pressure is reduced by the valve 5 and passed through the connecting pipe 6 to the indoor heat exchanger 7.
It evaporates and returns to the compressor 1 via the connecting pipe 8, the 4-way valve 2, and the accumulator 9. During this operation 1, the solenoid valve 12 located in the middle of the bypass path 11 is closed, but when oil accumulates, the solenoid valve 12 is opened by a signal, and the refrigerating machine oil that has accumulated at the bottom of the oil separator 10 is transferred to the bypass path. 11
is returned to the accumulator 9 via the solenoid valve 12, and returns to the compressor 1 together with the low temperature, low pressure gas returned from the indoor heat exchanger 7, so the refrigerating machine oil circulation circuit is large. shortened to width. The same applies to heating.

Therefore, even when the distance between the indoor unit and the outdoor unit is large, that is, when the connecting piping 6°8 is long, the refrigerating machine oil circulation circuit is a short bypass circuit, so the compressor 1 may run out of refrigerating machine oil. It never happens.

In addition, when the compressor 1 is of the capacity control type, the circulation amount of refrigerant discharged from the compressor is greatly reduced, and when the amount becomes small, the speed of the refrigerant moving in the pipes decreases. However, the distance of the circuit through which the refrigerating machine oil circulates does not change, and since it is short, there is no possibility of the refrigerating machine oil returning.

Furthermore, when the compressor 1 is started, the solenoid valve 12 is opened (7), and by keeping it open for a certain period of time (for example, 1 minute), the refrigerant lying in the refrigerating machine oil is removed from the compressor when the compressor is stopped. Shifting occurs upon start-up, and a large amount of refrigerating machine oil is discharged from the compressor 1 compared to normal continuous operation, but only the refrigerating machine oil is separated by the oil separator, and the refrigerating machine oil does not circulate through the refrigerant circuit, but instead flows through the bypass path. 11 and the accumulator 9 via the solenoid valve 12 which is open.
By supplying low-pressure gas to the compressor 1 again, it becomes possible to compensate for the shortage of refrigerating machine oil in a short time.

Furthermore, when switching from heating operation to defrost operation, the 4-way valve 2
The high temperature compressed by compressor 1 is switched.

The high-pressure refrigerant gas passes through a check valve 13 and an oil separator 10.
defrosting is performed in the outdoor heat exchanger 3 by means of the direction valve 2;
It passes through the distributor 4, is depressurized by the expansion valve 5, passes through the connection pipe 6, the indoor heat exchanger 7, and the connection pipe 8.
It is returned to the 4-way valve 2 and the accumulator 9 again. At the same time, the high-temperature, high-pressure gas exiting the compressor 1 is returned to the lower part of the oil separator 10, via the p-bypass circuit 11, through the solenoid valve 12, and into the accumulator 9 (8). In the accumulator S, the low temperature, low pressure refrigerant gas that has passed through the evaporator 7 is mixed with the high temperature that has passed through the bypass path 11.

Since the high-pressure refrigerant gas is mixed with the low-pressure gas, the pressure of the low-pressure gas is increased and returned to the compressor 1. As a result, the frost formed on the outdoor heat exchanger 3 can be defrosted in a short time when the specific volume is small and the circulation amount is large.

In addition, when the heating temperature is low, there is a risk of frost forming quickly, so the solenoid valve 12 is opened again and the bypass passage 11 is opened, and a part of the discharged gas bypasses the accumulation rake 9. It becomes possible to increase heating capacity.

Furthermore, by operating the compressor 1 at its maximum capacity when opening the solenoid valve 12 when the variable capacity compressor is used during defrosting and heating at low temperatures, the defrosting capacity and heating capacity are further improved. can get.

Furthermore, during cooling or heating, by opening the solenoid valve 12 after a certain period of continuous operation (for example, 30 minutes) after starting the compressor 1, the refrigeration that is constantly being discharged from the compressor 1 can be opened. The oil separator 10 that separates and stores the machine oil opens the bypass passage 11 and returns it to the accumulation lake 9 via the solenoid valve 12, and the low-temperature, low-pressure gas returned to the evaporator is used together with the compressor. 1. It becomes possible to replenish the refrigerating machine oil.

Also, because of this configuration, when the air conditioner is stopped, even if the refrigerant that had accumulated in the connecting pipe 8 returns to the discharge pipe of the compressor due to its own weight, it is forced into the oil separator 10 and becomes even more oily. By closing the check valve 13 located between the separator 10 and the compressor discharge side, it is possible to prevent refrigerant and refrigerating machine oil from entering the inside of the compressor discharge port side, and the check valve 13 is closed when the compressor is started. It also has the effect of preventing damage. The effect of spraying the check valve 13 will be further improved if it is installed so that the check valve closes when the pressures before and after the check valve 13 are balanced.

In the above embodiment, a split type compressor was used with the compressor located outside the room, but a remote type compressor with the compressor located inside the room could also be used.Also, an expansion valve was used as the throttling device, but a cabillary tube may also be used. It may be a type expansion valve or an Oriswiss type expansion valve, and the mounting position may be at any position between the indoor heat exchanger and the outdoor heat exchanger.

As described above, according to the present invention, the oil separator 10't is provided between the discharge side of the compression if and the four-way valve 2, and the oil separator reaches the accumulator day via the two valves 12. By providing a bypass passage 11 to return the refrigerating machine oil and hot gas to the accumulator 9, it is possible to easily make the installation tlII (connection piping 6.8) on the indoor side and the outdoor side extremely long, and Even if the refrigerant discharge amount from a variable capacity compressor or the like decreases significantly, the refrigerating machine oil can easily return to the compressor, and the low-temperature characteristics during defrost and heating are greatly improved, which improves the heating characteristics of heat pumps.

This has the effect that a device that improves comfort and reliability can be made extremely easily and inexpensively, and can be highly accurate.

In addition, a check valve 13 is installed between the discharge side of the pressure machine 1 and the oil separator 10 so as to close when the pressure in front of the check valve is balanced, so that the discharge when the air conditioner is stopped. It had accumulated inside the side connection pipe 8.

(11) It represents the flow of refrigeration oil.

Even if the refrigerant and refrigeration machine oil return to the discharge pipe of the compressor due to their own weight, they will remain in the oil separator 10, and the check valve 13 will be closed to prevent them from entering the discharge side of the compressor 1.
By being able to prevent valve damage when starting up the compressor 1, it is possible to create a device that does not impair reliability even if the connecting pipe 8 is lengthened, and can be made extremely easily and inexpensively, with high accuracy. It has various excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the conventional refrigeration cycle, and Fig. 2 is a diagram explaining the conventional refrigeration cycle. The figure explaining the refrigeration cycle which shows an example. 1 is a compressor, 2 is a four-way valve, 3 is an outdoor heat exchanger, 4 is a distributor, 15 is an expansion valve, 6 is a connecting pipe, 7 is an indoor heat exchanger, 8 is a connecting pipe, 9 is an accumulator , 10 is an oil separator, 11 is a bypass path, 12 is a solenoid valve, and 13 is a check valve.The solid line arrows represent the refrigerant flow during cooling and defrost operation.The broken line arrows represent the refrigerant flow during heating operation. The dashed line represents the refrigerant in the bypass path. (12) Agent Masuo Oiwa (2 others)

Claims (3)

[Claims] (1) In an air conditioner in which a compressor, a four-way valve, an outdoor heat exchanger, a throttling device, an indoor heat exchanger, and an accumulator are connected in a ring to form a circulation cycle, the compressor 1 An oil separator 10 is provided between the discharge side and the four-way valve 2, and a bypass path 11 is provided from the oil separator to the accumulator 9 via the stain magnetic valve 12.
A separate air conditioner characterized in that a reverse valve 13 is provided between the discharge side of the oil separator 10 and the oil separator 10. (2) The check valve 13 disposed between the discharge side of the compressor 1 and the oil separator 10 is closed when the pressures before and after the check valve are balanced. Air conditioner as described in section. (3) A check valve 13 between the discharge side of the compressor 1 and the four-way valve 2;
The XE kidney system is characterized in that it is arranged in the order of the oil separator 10 and further forms a bypass path 11 leading to the accumulator 9 via the solenoid valve 12.