KR20010095735A - Multi - airconditioner - Google Patents

Abstract

PURPOSE: A multiple type air conditioner is provided, in which refrigerant flow rate is adjusted by an additional expansion device during a single heating operation, to thereby prevent rapid rise of discharge pressure, sudden expansion of refrigerant and abnormal noise caused due to boiling of refrigerant. CONSTITUTION: A multiple type air conditioner comprises a compressor(62) for generating high temperature high pressure refrigerant; a single outdoor heat exchanger(65) and a plurality of indoor heat exchangers(50,53) for discharging hot or cold wind by the refrigerant fed from the compressor; a first expansion unit(71,74,77) for controlling flow rate and pressure of the refrigerant flowing between the outdoor heat exchanger and plural indoor heat exchangers during the simultaneous operation of cooling and heating; and a second expansion unit(89) for controlling flow rate and pressure of the refrigerant flowing between the outdoor heat exchanger and plural indoor heat exchangers during a single heating operation. The second expansion unit is configured to have a flow resistance lower than the flow resistance of the first expansion unit.

Description

Multi-Air Conditioner {Multi-airconditioner}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-air conditioner, and more particularly, to a multi-air conditioner that constitutes a heating and cooling cycle to more efficiently perform a cooling operation and a heating operation.

The multi-air conditioner uses a single compressor to use a plurality of indoor units for both heating and cooling. That is, the multi-air conditioner is provided with one outdoor side heat exchanger and a plurality of indoor side heat exchangers. Therefore, by selectively driving the indoor side heat exchanger as necessary to perform the heating and cooling control.

The conventional multi-air conditioner, as shown in Fig. 1, has an interior side having a plurality of heat exchangers 10, 13, ..., a compressor 22, a heat exchanger 25, a heating and cooling mode. According to the outdoor side including the four sides (16) for switching the refrigerant flow.

The multi-air conditioner also includes a solenoid valve 43, 46 for opening and closing the refrigerant flow between the outdoor heat exchanger 25 and the indoor heat exchanger 10, 13, ..., and a high pressure liquefied in the condenser. Expansion liquids (31, 34, 37) for adjusting the refrigerant to be easily evaporated in the evaporator by a reduced pressure to adjust the flow of the refrigerant at a constant rate, and check valve 28 for adjusting the refrigerant to flow in only one direction Doing. And reference numeral 19 is an accumulator, which is a kind of liquid refrigerant separator for preventing the liquid refrigerant from being sucked into the compressor. In addition, although not shown, an overload protector (O.L.Protector) for protecting the overload of the compressor 22 is included. The overload protector prevents the compressor from being damaged due to some cause when the compressor is started or the temperature of the compressor is increased due to the overload generated during operation, thereby causing damage to the motor. Therefore, the overload protector operates by the winding temperature of the compressor and the current value flowing thereto.

The following describes the operation cycle according to the cooling and heating mode of the conventional multi-air conditioner configured as described above.

First, in the cooling mode, the heat exchangers 10, 13, ... on the indoor side operate as evaporators in which cold wind is discharged. And the heat exchanger 25 of the outdoor side operates as a condenser in which hot wind is discharged.

Accordingly, the refrigerant discharged from the compressor 22 in the cooling mode under the control of the four sides is circulated in the direction indicated by the solid line, and the compressor 22 → the outdoor side heat exchanger 25 → the indoor side heat exchanger It passes through (10, 13, ...) and flows back into the compressor (22).

At this time, the high pressure liquid refrigerant is passed between the expansion device (34, 37) between the outdoor heat exchanger (25) acting as the condenser and the indoor heat exchanger (10, 13, ...) acting as the evaporator. . While passing through the expansion devices (34, 37), the high-pressure liquid refrigerant is adjusted to a state that is easy to depressurize and evaporate.

On the other hand, a plurality of heat exchangers 10, 13, ... on the indoor side are provided. Therefore, when the indoor heat exchanger (10, 13, ...) is operated at the same time as the operation alone, the refrigeration cycle is operated is configured and controlled differently.

If the user wants to operate all of the heat exchangers in the indoor side, the liquid refrigerant flowing from the outdoor heat exchanger 25 passes through the check valve 28 and then passes through the expansion valves 34 and 37. It goes down. Then, the solenoid valves 40 and 43 which maintain the open state are respectively supplied to the heat exchangers 10 and 13 on the indoor side.

However, when one of the indoor heat exchangers is to be operated, only one solenoid valve which is operated by the control of the four sides 16 maintains an open state. In this case, the flow rate control of the refrigerant supplied from the outdoor heat exchanger 25 is performed by the expansion valve 40. That is, the liquid refrigerant supplied from the outdoor side heat exchanger 25 passes through the expansion valves 37 and 34 and is then transferred to the solenoid valve side which is kept open through the expansion valve 40 and is in operation. It is supplied to the heat exchanger on the indoor side.

On the other hand, in the heating mode, the heat exchangers 10, 13, ... on the indoor side operate as a condenser for discharging hot wind. And the heat exchanger 25 of the outdoor side operates as an evaporator in which cold wind is discharged.

Accordingly, the refrigerant circulating direction is changed by the control of the four sides 16, and the refrigerant discharged from the compressor 22 is circulated in the direction of the arrow drawn by the dotted line, and the compressor 22 → the indoor heat exchanger 10, 13, .. .) → passes through the outdoor heat exchanger (25) and flows back into the compressor (22).

At this time, the high pressure liquid refrigerant passes through the expansion device (34, 37, 31) between the outdoor heat exchanger (25) acting as the evaporator and the indoor heat exchanger (10, 13, ...) acting as a condenser. Done. While passing through the expansion device, the high-pressure liquid refrigerant is depressurized and adjusted to evaporate easily.

By the way, in the heating operation mode, all solenoid valves are controlled to the open state regardless of when all the heat exchangers of the indoor side are operating and when any heat exchanger is operated among a plurality of heat exchangers.

This is because in the case of a multi-air conditioner using one compressor, since the capacity of the indoor heat exchanger is generally smaller than that of the outdoor heat exchanger, when only one heat exchanger of the plurality of indoor heat exchangers is operated, This is because the condensation temperature is so high that condensation is not sufficient and an error occurs in the operation of the compressor. Therefore, even when one indoor heat exchanger is operated, the solenoid valve is controlled to be open so that the refrigerant can pass through all the heat exchangers. Only in this case, the indoor heat exchanger, which should not be operated, controls the blowing to the off state.

However, in the conventional heating alone operation using a multi-air conditioner, since the refrigerant passing through the indoor side heat exchanger must pass through all the expansion devices 34, 37, and 31, the suction pressure due to the sudden drop in pressure is reduced. As the momentary down, the pressure on the discharge side rapidly rises, and thus the compressor overload protection device operates due to the pressure rise due to the refrigerant shortage. Due to this phenomenon, heating is not normally performed, and there is a problem in that abnormal noise (talk-talk-talk ---) occurs due to a decrease in heating efficiency, rapid expansion, and boiling of the refrigerant due to a lack of refrigerant.

Therefore, an object of the present invention is to control the refrigerant circulation amount by using a separate expansion device in the heating alone operation of the multi-air conditioner, thereby preventing a sudden increase in the discharge pressure due to the suction pressure decrease, and the rapid expansion of the refrigerant The present invention provides a multi-air conditioner which can prevent abnormal noise caused by refrigerant boiling.

1 is a configuration diagram of a heating and cooling cycle of a multi-air conditioner according to the prior art;

2 is a cooling and heating cycle configuration of a multi-air conditioner according to the present invention.

Explanation of symbols on the main parts of the drawings

10,13,25,50,53,65 Heat exchanger 16,56 Four sides

22,62: Compressor 31,34,37,40,71,74,77,80,89: Expansion device

43,46,83,86,92: Solenoid Valve

Multi-air conditioner according to the present invention for achieving the above object comprises a compressor for generating a high temperature and high pressure refrigerant; A single outdoor side heat exchanger and a plurality of indoor side heat exchangers for discharging hot wind or cold wind by the refrigerant supplied from the compressor; A first expansion device for controlling the flow rate and pressure of the refrigerant flowing between the one outdoor side heat exchanger and the plurality of indoor side heat exchangers during the cooling operation and the heating simultaneous operation; And a second expansion device for controlling the flow rate and the pressure of the refrigerant flowing between the one outdoor side heat exchanger and the plurality of indoor side heat exchangers during the heating alone operation, wherein the second expansion device includes a first expansion device. The flow resistance is set smaller than that of the device.

The first and second expansion apparatuses of the present invention are characterized in that they operate in conjunction with a solenoid valve that operates by controlling the four sides of the refrigerant in the cooling and heating mode.

Hereinafter, a multi-air conditioner according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a heating and cooling cycle of a multi-air conditioner according to the present invention.

The multi-air conditioner of the present invention, as shown, is equipped with a plurality of heat exchangers (50, 53, ...) in accordance with the interior, the compressor 62, the heat exchanger (65), the heating and cooling mode It consists of the outdoor side including the four sides 56, etc. for switching the refrigerant flow.

The multi-air conditioner also includes solenoid valves 83 and 86 for opening and closing the refrigerant flow between the outdoor heat exchanger 65 and the indoor heat exchangers 50, 53, ..., and the high pressure liquefied in the condenser. Expansion liquids (71, 74, 77) for adjusting the refrigerant to be easily evaporated in the evaporator by reducing the pressure of the liquid refrigerant to adjust the flow of the refrigerant at a constant rate, and check valve 68 for adjusting the refrigerant to flow in only one direction Doing.

Further, the multi-air conditioner of the present invention, when only any heat exchanger is operated in the heating mode (hereinafter referred to as " heating alone operation "), the outdoor side heat exchanger 65 and the indoor side heat exchanger 50, 53,. ..) solenoid valve 92 for opening and closing the refrigerant flow between the expansion device and the expansion device for adjusting the high-pressure liquid refrigerant liquefied in the condenser to adjust the condition to easily evaporate in the evaporator and to flow the refrigerant at a constant rate (89) ) Is included.

At this time, the expansion device 89, the flow resistance is configured to be smaller than the other expansion devices (71, 74, 77, 86). In order to make the flow resistance small, the inner diameter of the expansion device is increased at the same length, and the length of the expansion device is short at the same inner diameter.

And numeral 59 is an accumulator, which is a kind of liquid refrigerant separator for preventing the liquid refrigerant from being sucked into the compressor. In addition to this, although not shown, an overload protector (O.L.Protector) for protecting the overload of the compressor 62 is included. The overload protector prevents the compressor from being damaged due to some cause when the compressor is started or the temperature of the compressor is increased due to the overload generated during operation, thereby causing damage to the motor. Therefore, the overload protector operates by the winding temperature of the compressor and the current value flowing thereto.

The following describes the operation cycle according to the cooling and heating mode of the multi-air conditioner of the present invention configured as described above.

In the heating operation mode of the multi-air conditioner of the present invention, when all the indoor side heat exchangers are operated, they form the same heating operation cycle as in the prior art. That is, the solenoid valve 92 is in the closed state, and the other solenoid valves 83 and 86 are controlled to the open state.

Therefore, the refrigerant supplied from the indoor heat exchanger 50 is transferred to the expansion valve 74 side through the solenoid valve 86, and the refrigerant supplied from the other indoor heat exchanger 53 expands through the solenoid valve 83. It is delivered to the valve 77 side. After the pressure is lowered in each of the expansion valves 74 and 77, the delivered refrigerant is transferred to the outdoor heat exchanger 65 which is operated by the evaporator as the pressure is lowered through another expansion valve 71. That is, in the heating operation in which all the heat exchangers are operating, the refrigerant is circulated while forming the same heating operation cycle as in the prior art.

However, in the case of heating alone operation, all solenoid valves 83, 86 and 92 are controlled to be open by the control of the four-sided side 56. At this time, the expansion device 89 on the solenoid valve 92 side has a smaller flow resistance than the other expansion devices 74, 77 and 71.

Therefore, the refrigerant supplied through the indoor heat exchangers 50 and 53 passes through the solenoid valves 83 and 86 and then flows to the expansion valve 89 having a low flow resistance. That is, during the heating alone operation, the refrigerant flows in the " a " direction shown in FIG. 2 to form a heating cycle.

Therefore, the problems caused by passing through the expansion device (71, 74, 77) in the conventional heating alone operation cycle, the expansion is reduced, so that the suction pressure to the compressor and the resulting discharge pressure suddenly rises, heating due to malfunction of the compressor overload protector As a result of the decrease in efficiency and boiling due to the rapid expansion of the refrigerant generated through various expansion devices, problems such as abnormal noise generation have been solved.

In addition, the on / off control of each of the solenoid valves (83, 86, 92) is made by the control of the four sides 56 according to the heating and cooling operation, single / simultaneous operation. Since the operation control of the solenoid valve by control of the said four sides uses a well-known technique, detailed description is abbreviate | omitted.

On the other hand, the operation cycle of the multi-air conditioner in the cooling mode is the same as before. That is, during the cooling operation, the heat exchangers 50, 53, ... of the indoor side operate as an evaporator in which cold wind is discharged. And the heat exchanger 65 of the outdoor side operates as a condenser in which hot wind is discharged.

Accordingly, the refrigerant discharged from the compressor 62 in the cooling mode under the control of the four sides 56 is circulated in the direction indicated by the solid line, so that the compressor 62 → the outdoor side heat exchanger 65 → the indoor side heat exchanger. It passes through (50, 53, ...) and flows back into the compressor (62).

At this time, the high pressure liquid refrigerant is passed between the expansion device (74, 77) between the outdoor heat exchanger (65) acting as the condenser and the indoor heat exchanger (50, 53, ...) acting as the evaporator. . While passing through the expansion device (74, 77), the high-pressure liquid refrigerant is adjusted to a state that is easy to depressurize and evaporate.

On the other hand, many indoor heat exchangers 50, 53, ... are provided. Therefore, when the indoor heat exchanger (50, 53, ..) is operated at the same time when the operation alone, the refrigeration cycle is operated is configured and controlled differently.

When the user wants to operate all the heat exchangers in the indoor side, the liquid refrigerant flowing from the outdoor heat exchanger 65 passes through the check valve 68 and then passes through the expansion valves 74 and 77. It goes down. Then, the solenoid valves 83 and 86 which maintain the open state are respectively supplied to the heat exchangers 50 and 53 of the indoor side.

However, when one of the indoor heat exchangers is to be operated, only one solenoid valve which is operated by the control of the four sides 56 maintains an open state. In this case, the flow rate control of the refrigerant supplied from the outdoor side heat exchanger 65 is performed by the expansion valve 80. That is, the liquid refrigerant supplied from the outdoor side heat exchanger (65) passes through the expansion valves (87, 84) and is then transferred to the solenoid valve side which is kept open through the expansion valve (80) and is in operation. It is supplied to the heat exchanger on the indoor side.

As described above, the multi-air conditioner of the present invention, when controlling the heating and cooling operation using one compressor, to control the refrigerant circulation amount by using an expansion device with a low flow resistance during the heating alone operation. Therefore, when performing cooling simultaneous operation, cooling alone operation, heating simultaneous operation and heating alone operation, a separate expansion device is used. In this way, by using a separate expansion device during the heating alone operation, the pressure on the high pressure side is prevented from rising due to the lack of refrigerant circulation, the compressor protection device is prevented from operating due to the heating overload, and the abnormal noise caused by the refrigerant boiling The effect of solving problems such as occurrence can be obtained.

Claims (2)

A compressor for generating a high temperature and high pressure refrigerant; A single outdoor side heat exchanger and a plurality of indoor side heat exchangers for discharging hot wind or cold wind by the refrigerant supplied from the compressor; A first expansion device for controlling the flow rate and pressure of the refrigerant flowing between the one outdoor side heat exchanger and the plurality of indoor side heat exchangers during the cooling operation and the heating simultaneous operation; And a second expansion device for controlling the flow rate and the pressure of the refrigerant flowing between the one outdoor side heat exchanger and the plurality of indoor side heat exchangers in a heating alone operation, And said second expansion device is set to have a smaller flow resistance than the first expansion device. The method of claim 1, And said first and second expansion devices operate in conjunction with a solenoid valve operated by four-way control to adjust the circulation direction of the refrigerant according to the cooling and heating modes.