JPS605863B2 - Air conditioning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to improve the cooling capacity of a heat pump air-conditioning system and to prevent the growth of ice on a defrost drain to an outdoor heat exchanger during heat pump heating operation.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 is an indoor unit, 2 is an outdoor unit, and 3 is a refrigerant tube unit.

In the indoor unit 1, 4 is a compressor, 5 is a four-way valve, and 6 is a compressor.
is an indoor heat exchanger, 7 is a gas side branch pipe provided at one end of each of the plurality of divided circuits that divide the refrigerant flowing through the indoor heat exchanger 6, and 8 is a gas side branch pipe provided at one end of each of the plurality of divided circuits of the indoor heat exchanger 6. A main capillary tube for heating and cooling is directly connected to the other end and has a large throttle resistance, 9 is a filter, 10 is an accumulator, 11 is a joint, and 12 is an indoor fan. In the outdoor unit 2, 13 is an outdoor heat exchanger, 14 is a gas side branch pipe provided at one end of each of the outdoor heat exchangers 13 forming a plurality of divided circuits like the indoor heat exchanger 6, and 15 is an outdoor heat exchanger. An auxiliary capillary tube for heating and cooling that is directly connected to one end of each of the plurality of divided circuits of the heat exchanger 13 and has a small throttle resistance, 16 is a filter, 17 is a check valve, 18 is a capillary tube exclusively for heating, and 19 is a liquid receiver. One end of a heating capillary 18 is connected to the lower liquid phase, and one end of a check valve 17 is connected to the upper gas phase. 20 is a joint, 21 is an outdoor fan, and 22 is a subcooling heat exchanger.

The supercooling heat exchanger 22 significantly subcools the liquefied medium that is condensed at high pressure, thereby ensuring safe heating and cooling performance and operating characteristics. In other words, in the case of cooling operation, the compressor 4
The high-pressure cold soot gas that flows from the four-way valve 5 into a plurality of branches through the gas side branch pipes 14 and flows into the outdoor heat exchanger 13 is air-cooled by the outdoor fan 21 in each branched refrigerant circuit, and is condensed and liquefied. This is a big problem when the soot is divided into several circuits to the indoor/outdoor heat exchangers 6 and 13 because it does not necessarily condense evenly and is not supercooled due to the distribution of soot and the distribution of the soot distribution. Met. The present invention is based on the above points, and in order to reliably achieve significant supercooling, the soot coming out of each branch circuit from the outdoor heat exchanger 13 is filtered through the filter 6 and the auxiliary capillary tube 15 for heating and cooling. The cold soot liquid is collected from the valve 17 into a liquid receiver 19 and flows from below the liquid receiver 19 to the supercooling heat exchanger 22 of the present invention to ensure a predetermined degree of supercooling. This subcooling heat exchanger 22 uses a lower tube attached to the same fin as the fin-tube type outdoor heat exchanger 13, and therefore,
It is supercooled by the outdoor fan 21. The supercooled refrigerant flows into the indoor unit, is branched from the filter 3 through the main capillary tube 8 for heating and cooling, and is used for cooling in the indoor heat exchanger 6. At this time, since the subcooling heat exchanger 22 has sufficiently subcooled the refrigerant liquid, it is easy for the complete refrigerant liquid to flow uniformly into the main capillary tube 8 used for cooling and heating, and therefore, the contamination of cold soot gas etc. There is no variation in the flow of air, stabilizing the operating characteristics, and guaranteeing an improvement in cooling capacity commensurate with the degree of supercooling. As described above, in the embodiment of the present invention, even if the refrigerant in the indoor and outdoor heat exchangers 6 and 13 is divided into several circuits and flows, in the outdoor heat exchanger 13, the cooling and heating common auxiliary capillary provided at the cold soot outlet By making the throttling resistance of the tubes 15 uniform and also by making the throttling resistance of the main capillary tube 8 for air conditioning and heating provided at the refrigerant inlet of the indoor heat exchanger 6 uniform, the refrigerant flow rate to each branch circuit can be made the same. Therefore, it is possible to perform heat exchange by effectively utilizing the entire areas of the indoor and outer heat exchangers 6 and 13 evenly.

As a result, the degree of subcooling of the condensed refrigerant liquid in the outdoor heat exchanger 13 becomes uniform, and the degree of subcooling of the refrigerant liquid from the receiver 19 after merging the branched cold soot is transferred to the subcooling heat exchanger 22. By increasing the size of the air conditioner, the cooling capacity is further improved. In addition, the throttling resistance of the auxiliary capillary tube 15 for both air conditioning and heating connected to the outdoor heat exchanger 13 is made smaller than that of the main capillary tube 8 for air conditioning and heating, and the main purpose is to equalize the refrigerant distribution in the outdoor heat exchanger 13. This reduces the evaporation of soot due to pressure loss in the auxiliary capillary tube 16 used for cooling and heating, and the evaporation of cold soot during cooling is caused by the large throttling resistance in the main capillary tube 8 for heating and cooling at the inlet of the indoor heat exchanger 6. Since this is performed by a pressure drop decompression action, the indoor heat exchanger 6 can perform a cooling action with good performance.

On the other hand, in the case of heating operation, the high-pressure refrigerant gas that flows from the compressor 4, four-way valve 5, and gas side branch pipe 7 to the indoor heat exchanger 6 has a heating effect and is condensed and liquefied, and the main capillary tube 8, which is used for heating and cooling, and the filter At 9pm, soot flows into the outdoor unit 2 from the joint 11, the soot piping unit 3, and the joint 20. The problem with heating operation using a heat pump during winter is a reduction in heating capacity due to frost formation on the outdoor heat exchanger 13 and freezing of the defrosting drain at low outside temperatures. In other words, when the defrost drain flows down the fins of the outdoor heat exchanger 13, it freezes and the ice grows from the bottom of the outdoor heat exchanger 13 upwards, and the outdoor heat exchanger 13 is gradually damaged by the ice. The problem is that it loses its function as a heat exchanger significantly if it is surrounded. The present invention solves this problem by preventing freezing. In other words, since the subcooling heat exchanger 22 is provided at the lower stage of the same fin as the outdoor heat exchanger 13, the temperature is maintained from about 45 qC to about 20 qC, so the dripping drain does not freeze. It is. In other words, the refrigerant liquid condensed in the indoor heat exchanger 6 is partially evaporated due to the pressure drop and depressurization action of the main capillary tube 8 used for both cooling and heating, becoming a gas-liquid two-phase state, flowing to the outdoor unit 2, and flowing into the subcooling heat exchanger 22. flows into. In the subcooling heat exchanger 22, the gas-liquid two-phase refrigerant cooled by the low outside temperature and the drain water of the outdoor heat exchanger 13 performs condensation and liquefaction again, and with this condensation heat,
The supercooling heat exchanger 22 maintains a temperature of about 45q0 to about 2000, depending on the indoor and outdoor operating temperature conditions, and serves to prevent the dripping drain from freezing. The cold soot liquid recondensed in the supercooling heat exchanger 22 is then diverted from the liquid receiver 19 to the outdoor heat exchanger 13 via the heating capillary tube 18, the filter 16, and the auxiliary cooling/heating common capillary tube 15. , which evaporates. Therefore, in response to the low-temperature evaporation action of the refrigerant in the outdoor heat exchanger 13, the defrosting drain does not surround the outdoor heat exchanger 13 due to freezing, and the evaporation is promoted by efficiently exchanging heat. This prevents the performance from decreasing and also stabilizes the operating characteristics even in cold regions. In addition, during heating operation, the heating-only capillary tube 18 is provided to compensate for the lack of pressure loss and depressurization in the cooling/heating auxiliary capillary tube 15 with low throttling resistance. By absorbing heat from the refrigerant and completely evaporating it, heating capacity is improved and unevaporated refrigerant liquid is prevented from flowing into the compressor 4, thereby preventing malfunctions due to liquid compression in the compressor 4.

The present invention improves the cooling and heating capacity of a heat pump type air-conditioning device, especially a device in which an indoor-outdoor heat exchanger is configured with a plurality of refrigerant division circuits, such as a relatively large-capacity package air conditioner. This prevents the growth of ice on the defrost drain to the exchanger, and has the following effects.

■ The outdoor heat exchanger is equipped with an auxiliary capillary tube for both air conditioning and heating, which has low throttling resistance, and the indoor heat exchanger is equipped with a main capillary tube for air conditioning and heating, in each of the multiple refrigerant division circuits, so that the indoor heat can be transferred during both air conditioning and heating operation. It is possible to make the division of refrigerant in the exchanger uniform over the entire area of the heat exchanger, and it is possible to improve the heating and cooling capacity by effectively using the heat exchanger.

■ Even though the outdoor heat exchanger is equipped with an auxiliary capillary tube for both heating and cooling, the throttling resistance is kept small, so the evaporation of cold soot is carried out only in the indoor heat exchanger with the main capillary tube for heating and cooling. No reduction in performance.

In addition, during heating operation, the lack of pressure reducing effect in the auxiliary capillary tube for heating and cooling installed in the outdoor heat exchanger is compensated for by installing a dedicated capillary tube for heating, which reduces the evaporation of soot in the outdoor heat exchanger. This has been done perfectly, improving the absorption of heat from the air and improving heating capacity, as well as preventing liquid backflow into the compressor. ■ To prevent freezing of the defrosting drain to the outdoor heat exchanger during noren operation, the partially evaporated gas-liquid phase of the cold soot liquid is flowed into the supercooling heat exchanger using the main capillary tube used for heating and cooling, and is recondensed. The condensation heat generated by the action keeps the lower part of the outdoor heat exchanger warm, completely preventing the drain from freezing.

[Brief explanation of drawings]

The figure is a refrigerant circuit diagram of a heating and cooling system according to an embodiment of the present invention. 1...Indoor unit, 2...Outdoor unit, 3...Refrigerant piping unit, 4...Compressor, 5...Four-way valve, 6... ...Indoor heat exchanger, 8...Main capillary tube for air conditioning and heating, 15
・・・・・・Auxiliary capillary tube for heating and cooling, 17
...Check valve, 18...Capillary tube for heating, 19...Liquid receiver, 22...
Supercooling heat exchanger.

Claims (1)

[Claims] 1. In the refrigerant circuit that makes up the heat pump air conditioning system,
A common main capillary tube for heating and cooling that is directly connected to one end of each of the plurality of refrigerant division circuits that constitute the indoor heat exchanger and has a large throttling resistance, and a main capillary tube that is directly connected to one end of each of the plurality of refrigerant division circuits that constitute the outdoor heat exchanger and has a large throttling resistance. Auxiliary cooling/heating capillary tubes with reduced throttling resistance are connected to each other, and a check valve, a liquid receiver, and an appropriate cooling heat exchanger are sequentially installed between the cooling/heating/common auxiliary capillary tube and the cooling/heating/common main capillary tube. One end of a heating capillary tube connected in series, the other end of which was connected between the cooling/heating common auxiliary capillary tube and the check valve, is connected to the lower liquid phase part of the liquid receiver, and the supercooling heat exchange The container is placed at the lower end of the outdoor heat exchanger,
During heating operation, a three-stage pressure reduction mechanism is used from the main capillary tube used for cooling and heating, to a dedicated capillary tube for heating, and to an auxiliary capillary tube used for cooling and heating, and during cooling operation, from the auxiliary capillary tube used for cooling and heating to the main capillary tube used for cooling and heating. A heating and cooling system with a two-stage pressure reduction mechanism.