JPS6143192Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to an outdoor cooling unit that uses a capillary reach tube as a pressure reducing mechanism while improving its refrigerant flow rate control performance, preventing liquid from returning to the compressor, and maintaining the effective energy ratio of the device. It guarantees stable operation when installed in combination with one indoor unit in anticipation of future expansion, reduces initial costs, and allows simultaneous operation of two units after expansion. To provide an outdoor unit for two rooms that can perform cooling operation without causing excess or deficiency of refrigerant even when only one indoor unit is operated. There is a type of cooling system in which two indoor units are connected in parallel to one outdoor unit, and a capillary reach tube is used as a pressure reducer for the purpose of providing a low-cost product. While there is naturally a difference in the amount of refrigerant required during indoor operation, the fixed control performance of the capillary reach tube has the disadvantage of causing excess or shortage of refrigerant, making stable operation impossible. Therefore, if you are planning to expand the unit in the future and are using it in combination with one indoor unit, if you want to add the remaining unit, you will not only need to add the indoor unit, but you will also need to fill it with refrigerant. It is unavoidable that additional installation costs will increase, and it is uneconomical as it requires a large number of man-hours and troublesome handling. In view of the current situation where such problems are still unsolved, the present invention provides an outdoor unit with a new configuration that can fundamentally eliminate the above-mentioned defects and provide a low-cost device. Its characteristics are the main capillary reach tube for each indoor unit, which provides the optimal amount of shared pressure reduction during two-room operation, and the on-off valves installed on the outlet sides of the main capillary reach tubes. A bypass pipe is connected in parallel to each of the high-pressure branch pipes provided via an auxiliary capillary reach tube, and a liquid reservoir is arranged in a heat exchange manner to the low-pressure gas pipe, and the liquid reservoir is It has a configuration in which the container is connected via piping to the main capillary reach outlet side corresponding to the additional indoor unit. Hereinafter, the content of the present invention will be explained in detail using one embodiment of the air conditioner shown in the drawings. In the figure, 1 is an outdoor unit, 2a is the first indoor unit to be installed initially, and 2b is an additional indoor unit to be installed as a second unit. The indoor units 2a and 2b are composed of an accumulator 6, a liquid reservoir 7, and a liquid receiver 16, while the indoor units 2a and 2b are composed of evaporators 9c and 9b and an indoor fan (not shown). The outdoor unit 1 has branch pipes 10a, 10b with the high pressure liquid pipe 5 corresponding to both indoor units 2a, 2b.
An on-off valve 1 is installed in each branch pipe 10a, 10b.
For example, electromagnetic valves 2a and 12b are provided, and a pressure reducing mechanism 8 is disposed in association with the branch pipes 10a and 10b. The pressure reducing mechanism 8 has a main capillary reach tube 11 interposed between the branch point 17 of both branch pipes 10a, 10b and each on-off valve 12a, 12b.
a, 11b and their main capillary reach tube 1
1a, 11b, and an auxiliary capillary reach tube 14 interposed in a bypass pipe 13 that connects the branch pipes 10a, 10b between the on-off valves 12a, 12b in parallel. On the other hand, the liquid reservoir 7 is provided so as to be able to exchange heat with the low-pressure gas pipe 18 in the outdoor unit 1. The arrangement is integrated into a compact structure. In addition, the internal volume of the liquid storage container 7 is the difference between the amount of refrigerant required to be filled into the refrigerant circuit when one indoor unit is operated and the amount of refrigerant that is required when two indoor units are operated, and The size shall be large enough to accommodate the amount of refrigerant required for air purging during on-site installation work when only one indoor unit is connected. Then, the three-pronged portion 20 that communicates with the liquid reservoir 7, the outlet side of the main capillary reach tube 11b, the inlet side of the on-off valve 12b, and the bypass pipe 13 is connected to the piping 1.
5 to form a refrigerant circuit of the outdoor unit 1. In the figure, reference numeral 19 is a check valve that functions to prevent backflow in order to maintain the airtightness of the low-pressure gas pipe 18. However, the main capillary reach tubes 11a, 11
b is a main pressure reducer for controlling the refrigerant corresponding to each indoor unit 2a, 2b, and these can exhibit an optimal operating state when all rooms are operated by simultaneous operation of the indoor units 2a, 2b. As shown, the amount of pressure reduction to be shared by each unit is set to an appropriate value, but if the indoor units 2a and 2b have the same capacity, the amount of pressure reduction to be shared will naturally be the same, taking into consideration the capacity of the outdoor unit 1. Needless to say. In the cooling system configured as described above, the outdoor unit 1 has an amount of refrigerant suitable for the total amount of refrigerant when two units are operated and an amount of refrigerant corresponding to the amount of loss during air purge performed when connecting both indoor units 2a and 2b. Fill it in advance. First, when connecting only the first indoor unit 2a to the outdoor unit 1, air purge is performed when connecting the indoor unit 2a.
The amount of refrigerant in the refrigerant circuit is 1 compared to the initial amount charged.
This means that the amount of refrigerant reduced by the amount of refrigerant for the second air purge is being filled. To perform cooling operation of the indoor unit 2a, the on-off valve 12b is closed and the on-off valve 12a is opened. By doing this, the refrigerant liquid that has passed through the condenser 4 is divided into the branch pipes 10a and 10b, and the refrigerant is decompressed in the main capillary reach tube 11a, the main capillary reach tube 11b, and the auxiliary capillary reach tube 1.
After passing through 4 and joining together with the depressurized refrigerant liquid, it passes through the on-off valve 12a and flows into the evaporator 9a of the indoor unit 2a.
After being evaporated and liquefied, the accumulator 6
The air is sucked into the compressor 3 through the During this cooling operation, the pressure in the three-pronged section 20 is in the intermediate pressure region and is higher than the pressure in the low-pressure gas pipe 18, so the refrigerant temperature in the accumulator 6 becomes lower than the refrigerant temperature in the three-pronged section 20, and as a result, The inside of the liquid reservoir 7 is cooled by the low-pressure gas in the accumulator 6, and the refrigerant is condensed and liquefied and stored in a filled state throughout the inside of the liquid reservoir 7. Therefore, if the liquid storage container 7 has the predetermined capacity, the refrigerant will be adjusted and the amount of refrigerant circulated in the refrigerant circuit will be sufficient for one vehicle, eliminating problems such as refrigerant accumulation in the condenser 4. Next, a case will be described in which a second indoor unit 2b is additionally connected to perform cooling operation in two rooms at the same time. At this time, in order to perform air purge on the second unit,
The refrigerant circuit is filled with refrigerant whose amount of air purge is further reduced than the amount of refrigerant charged after one unit is connected. When both the on-off valves 12a and 12b are opened, the refrigerant gas discharged from the compressor 3 is
It exchanges heat with the outside air in the condenser 4 and becomes a high-pressure liquid refrigerant, which is divided into branch pipes 10a and 10b, and after being depressurized in the main capillary reach tubes 11a and 11b, respectively, it passes through the on-off valves 12a and 12b to each of the indoor units 2a and 2b. It reaches the evaporators 9a, 9a, where it evaporates due to heat absorption from the indoor air, becomes refrigerant gas, and flows into the low-pressure gas pipe 18.
After passing through the accumulator 6, the compressor 3
is inhaled. In this way, simultaneous cooling of two rooms is performed, but when there is a high cooling load due to a rise in room temperature, the evaporator 9a,
Since the amount of heat exchanged at 9b is large, the degree of superheating of the suction gas is large, and therefore each main capillary tube 1
The temperature of the suction gas becomes higher than the refrigerant temperature at the exits of 1a and 11b. As a result, the main capillary reach tubes 11a, 1
When low-pressure refrigerant liquid is accumulated in the liquid reservoir 7, which is in approximately the same state as the outlet section 1b, this refrigerant will be heated and evaporated by the superheated suction gas in the accumulator 6, and the liquid reservoir will be heated and evaporated. 7, only gas refrigerant exists and does not become liquid and accumulate.
A required amount of refrigerant adapted to the high cooling load is circulated within the refrigerant circuit. On the other hand, when the cooling load is low due to a drop in room temperature, the amount of heat exchanged in the evaporators 9a and 9b is small and the degree of superheating of the suction gas is small, due to pressure loss due to the piping on the downstream side of the main capillary reach tubes 11a and 11b. Since the suction gas temperature is rather lower than the refrigerant temperature at the outlet of the main capillary reach tubes 11a and 11b, liquid refrigerant equivalent to the surplus refrigerant amount is accumulated in the liquid storage container 7, thus reducing the cooling load. The adapted required amount of refrigerant is circulated within the system. Furthermore, when the operation of the first indoor unit 2a is stopped and only the second indoor unit 2b is operated, the on-off valve 12a is closed and the on-off valve 12b is opened to perform cooling operation. In this case, the temperature inside the accumulator 6 and the temperature inside the liquid reservoir 7 have a difference commensurate with the resistance on the low pressure side including the indoor unit 2b, and the saturation temperature of the three-pronged portion 20 is the same as that of the low pressure gas pipe 18. The refrigerant is stored in the liquid storage container 7 so that the refrigerant has a value equal to the sum of the saturation temperature and the degree of superheat. When the system runs out of gas, the refrigerant in the liquid reservoir 7 flows out into the system, and when the amount of gas increases, the refrigerant accumulates in the liquid reservoir 7. In this way, even when only the second unit is in operation, the liquid reservoir 7 adjusts the amount of refrigerant to ensure stable operation of the system. The following results were obtained by actually measuring each element under actual operating conditions to ensure that these three operating modes are effectively achieved.Accordingly, the amount of refrigerant can be adjusted appropriately and stable cooling operation can be achieved. It is proven that the In the table below, pressures P ₁ , P ₂ , P ₃ , P ₄ , P ₅ and temperatures t ₁ , t ₂ , t ₃ , t ₄ correspond to the respective parts shown in the figure.

[Table] As is clear from the above explanation, in the outdoor unit of the present invention, the high pressure liquid pipe 5 is branched into branch pipes 10a and 10b corresponding to the first indoor unit 2a and the second indoor unit 2b. The branch pipes 10a, 10b are provided with on-off valves 12a, 12b, respectively, and the main capillary reach tubes 11a, 11b are provided between the branch points 17 of both branch pipes 10a, 10b and the on-off valves 12a, 12b, respectively. In addition to providing
Branch pipes 10a, 10 between each main capillary reach tube 11a, 11b and each on-off valve 12a, 12b
(b) A bypass pipe 13 is provided to communicate with each other in parallel, and an auxiliary capillary reach tube 14 is interposed in the bypass pipe 13, and a liquid reservoir 7 is arranged to be able to exchange heat with the low pressure gas pipe 18. , this liquid storage container 7 is connected to the on-off valves 12a,
12b and the main capillary reach tube 1
Since the piping is connected between one of the indoor units 11b and the auxiliary capillary reach tube 14, the refrigerant is not stored in the condenser during partial load operation when one of the indoor units is operated. As a result, the effective area of the heat transfer part of the condenser can be utilized to nearly 100%, improving cooling capacity, while preventing liquid from returning to the compressor, and further improving compressor movement. The power is reduced, the effective energy ratio is improved, and running costs are also reduced. On the other hand, during full load operation when two chambers are operated simultaneously, when the load is high, the liquid is not stored in the liquid storage container.
At low loads, the refrigerant is automatically stored as a liquid, which allows the amount of circulating refrigerant to be adjusted, ensuring stable operation regardless of the light or heavy load, and further limiting overheating or dampness of the suction gas. Since it is adjusted so that the load falls within the following range, it is also effective in reducing the load on the compressor. In addition, if you are planning to purchase more units in the future and are installing one indoor unit and operating it, or if you are installing two indoor units and operating only one unit, you can operate it without any problems. It has the advantage of being able to meet customer needs and is also excellent in terms of sales promotion.

[Brief explanation of the drawing]

The figure is a piping system diagram of an air conditioner according to an embodiment of the outdoor unit of the present invention. 1...Outdoor unit, 2a, 2b...Indoor unit, 5...High pressure liquid pipe, 7...Liquid reservoir, 10
a, 10b...High pressure branch pipe, 11a, 11b...
Main capillary reach tube, 12a, 12b...on/off valve, 13...bypass pipe, 14...auxiliary capillary reach tube, 15...piping, 17...branch point, 18...low pressure gas pipe.

Claims (1)

[Scope of utility model registration request] This is an outdoor unit 1 to which two indoor units 2a, 2b can be connected, and a high pressure liquid pipe 5 is branched corresponding to both indoor units 2a, 2b to form a branch pipe 10.
a, 10b, and each branch pipe 10a, 10b
On-off valves 12a and 12b are provided respectively in both branch pipes 1.
0a, 10b branch point 17 and each on-off valve 12a,
12b, the main capillary reach tube 11a,
11b, and each main capillary reach tube 11a, 11b and each on-off valve 12a, 12
A bypass pipe 13 is provided that connects the branch pipes 10a and 10b in parallel with each other, and an auxiliary capillary reach tube 14 is interposed in the bypass pipe 13, while the liquid reservoir 7 is connected to the low pressure gas pipe 18. The liquid storage container 7 is connected to the piping 15 by disposing it so as to be able to exchange heat.
Accordingly, one of the on-off valves 12a and 12b 12
An outdoor unit for two rooms, characterized in that it is connected to piping between one of the main capillary reach tubes 11a and 11b and the auxiliary capillary reach tube 14.