JPH0113972Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in multi-room air conditioners. 2. Description of the Related Art As a conventional multi-chamber air conditioning system, for example a two-chamber cooling system, one having the structure shown in FIG. 1 is known. In the figure, 1 is an outdoor unit. This unit 1 includes a compressor 2, a condenser (outdoor heat exchanger) 3, and a refrigerant receiver 4 arranged sequentially in the flow direction of the refrigerant.
These are connected by main pipes 5 ₁ and 5 ₂ . The main pipe ₅₃ on the upstream side of the compressor 2 is branched into two first branch pipes 6a and 6b.
Further, the main pipe ₅₄ of the latter stage pipe of the refrigerant receiver 4 is branched into two second branch pipes 7a and 7b, and these branch pipes 7a and 7b have electromagnetic valves 8a and 8b from the container 4 side, respectively. Capillary tubes 9a and 9b are successively interposed. Then, the first branch pipes 6a, 6b and the second
An indoor unit 10 is installed between the branch pipes 7a and 7b, respectively.
a, 10b are interposed. These indoor units 10a and 10b have an evaporator (indoor heat exchanger) 11
a, 11b. In the two-chamber cooling system configured as described above, when operating only one outdoor unit 10a, the solenoid valve 8
At the same time as opening the solenoid valve 8b, the refrigerant from the compressor 2 is supplied to the evaporator 11a through the condenser 3, the refrigerant receiver 4, and the capillary tube 9a. When operating only the other indoor unit 10b , the solenoid valve 8a is closed and the solenoid valve 8b is opened to supply refrigerant to the evaporator 11b. In addition, two indoor units 10a , 1
When operating the two evaporators 11a and 11b at the same time, the solenoid valves 8a and 8b are opened to supply refrigerant to the two evaporators 11a and 11b. In the above-mentioned two-chamber cooling system shown in FIG. 1, the capillary tubes 9a and 9b for controlling the refrigerant flow rate must support both one-unit operation and two-unit operation. However, since these capillary tubes 9a and 9b have a fixed resistance determined by the tube inner diameter and length, it is difficult to deal with changes in flow rate. That is, when one evaporator 11a is in operation (the evaporator 11a is in operation), the refrigerant is not supplied to the other evaporator 11b and is in a low-pressure gas state, and the refrigerant discharged from the compressor 2 flows from the capillary tube 9a. Therefore, the liquid level in the refrigerant receiver 4 is maintained at the level A-A'. At this time, the capillary tube 9a is connected to the evaporator 1.
It is selected so that an appropriate flow rate flows through 1a. Similarly, the capillary tube 9b is also selected to allow an appropriate flow rate to flow into the evaporator 11b. On the other hand, when the two units are in operation, the refrigerant is supplied to the evaporators 11a and 11b, so the refrigerant flows through both the capillaries 9a and 9b, and the liquid level in the refrigerant receiver 4 drops to the position BB'.
In other words, when one unit is operated, the A- of the liquid receiver 4 is
The amount of refrigerant corresponding to the difference between A' and B-B' is
However, when two units are operated, the amount of refrigerant that was present in the evaporators 11a, 11b will be transferred to the evaporators 11a, 11b, etc. The refrigerant circulation amount discharged from compressor 2 when one unit is operated is 100.
When two units are operated, there are two evaporators, so the evaporation capacity increases and the amount of refrigerant circulated discharged from the compressor decreases.
Increases to about 130. However, since the capillary tube is selected to correspond to the operation of one unit, it is set to flow a refrigerant circulation amount of 100. As a result, when two units are operated, the capillary tube should be throttled to flow a refrigerant flow rate of 130/2 = 65 in response to the circulating amount of refrigerant discharged from the compressor, but since the capillary tube has a fixed resistance, it is not throttled enough, resulting in high and low pressure. The pressure difference decreases, the evaporation temperature rises, and the capacity of the evaporator decreases, and at the same time, refrigerant exceeding the evaporation capacity is supplied. This results in a liquid back operation in which the compressor sucks unevaporated liquid refrigerant, reducing the operating efficiency of the cooling system and causing damage to the compressor. As an improvement to the above-mentioned device, as shown in Fig. 2, the liquid receiver is omitted, and instead of the capillary tube, temperature sensing tubes 12a and 12b installed in the branch pipes 6a and 6b between the compressor 2 and the indoor units 10a and 10b are used to send the detection signal. A two-chamber cooling device using expansion valves 13a and 13b that are operated by the following is known. However, since such a cooling device uses expansion valves 13a and 13b, it is more expensive than a capillary tube. Expansion valve 13
There are moving parts in a and 13b, which has disadvantages such as poor reliability. The present invention was developed in view of the above-mentioned circumstances, and involves arranging a refrigerant amount regulating container to exchange heat with the piping on the indoor unit side of the compressor, and connecting the container to the piping connecting the capillary tube and the indoor unit. Accordingly, the present invention aims to provide a multi-room air conditioner in which surplus refrigerant during two-unit operation is collected into the refrigerant amount adjustment container, and liquid back operation caused by improper capillary operation is maintained at proper operation. Hereinafter, the present invention will be explained in detail based on the embodiment shown in FIG. It should be noted that the same members as those of the device shown in FIG. As shown in FIG. 3, the two-chamber cooling system of the present invention has a refrigerant amount adjusting container 14 disposed in the main pipe ₅₃ on the indoor units 10a , 10b side of the compressor 2 so as to surround the pipe ₅₃ . , the container 14 is connected to the capillary tube 9a
It has a structure in which it is connected via a connecting pipe 15 to a branch pipe 7a between the indoor unit 10a and the indoor unit 10a. Next, the operation of the two-chamber cooling device of the present invention will be explained. [] Effects when operating one unit By compressing the refrigerant with the compressor 2 of the outdoor unit 1, the refrigerant that has become high temperature and high pressure is transferred to the main pipe 5 ₁
The liquid is sent to the condenser 3 through which it is liquefied and condensed. At this time, when operating the indoor unit 10a and stopping the indoor unit 10b , open the solenoid valve 8a installed in the branch pipe 7a and close the solenoid valve 8b installed in the branch pipe 7b to drain the refrigerant in the condenser 3. Main pipe 5 ₂ , liquid receiver 4 , main pipe 5 ₄ , branch pipe 7a, capillary tube 9
a. It is supplied to the evaporator 11a of the indoor unit 10a through the branch pipe 7a. In such supply of refrigerant to the evaporator 11a, the capillary tube 9a is connected to the evaporator 11a.
Since the resistance value (pipe inner diameter and length) is determined so that an appropriate amount of refrigerant is sent to the evaporator 11a,
Main pipe 5 as the outlet of the compressor 2 and the suction pipe of the compressor 2
₃ , an appropriate degree of superheat is maintained. Therefore,
The liquid level of the refrigerant receiver 4 is at the position A-A', and the main pipe 5 ₃ is in an overheated state, so the main pipe 5 ₃
refrigerant amount adjustment container 14 arranged so as to surround the
Inside there is only superheated gas and no liquid refrigerant. At this time, the refrigerant is evaporated in the evaporator 11a to cool the indoor unit 10a , and the evaporated refrigerant is sucked into the compressor 2 through the branch pipe 6a and the main pipe ₅₃ to complete a cooling cycle. On the other hand, the evaporator 1 of the stopped indoor unit 10b
Refrigerant is not supplied to 1b by the action of the electromagnetic valve 8b, but is sucked through the main pipe 5 ₃ and the branch pipe 6b by compression 2, so only gaseous refrigerant is present and no liquid refrigerant is present. Note that even when the indoor unit 10a is stopped and the indoor unit 10b is in operation, the selection of the capillary is the same, except that the refrigerant flowing through the solenoid valve and the capillary is reversed. [] Effect when two units are operated When the indoor units 10a and 10b are operated at the same time, the solenoid valves 8a and 8b are opened to supply refrigerant to the two evaporators 11a and 11b. Therefore, the refrigerant flows through both the capillary tubes 9a and 9b, and the amount of refrigerant supplied to the low pressure side increases compared to when one unit is operated, so the liquid level in the liquid receiver 4 drops to the position B-B'. . As mentioned above, the capillary tubes 9a and 9b are selected to ensure an appropriate flow rate of refrigerant when one unit is in operation, but when two units are in operation, the resistance is too small and excessive refrigerant is supplied to the evaporator and the compressor 2 is There was a possibility of inhaling unevaporated liquid refrigerant. In the present invention, a refrigerant amount adjustment container 14 is installed to exchange heat with the main pipe ₅₃ serving as the suction pipe of the compressor 2, and is connected to the branch pipe 7a between the capillary tube 9a and the evaporator 11a by a connecting pipe 15. . For this reason, the refrigerant amount adjustment container 14
The refrigerant inside is cooled, condensed, and liquefied by unevaporated liquid refrigerant passing through the suction pipe. Therefore, when two units are operated, the refrigerant that is excessively supplied to the low pressure side is
Only the surplus refrigerant is stored in the refrigerant amount adjustment container 14 provided on the low pressure side, the required amount of refrigerant is supplied to the evaporators 11a and 11b, and the compressor 2 sucks the unevaporated liquid refrigerant. can be prevented. In this case, the size of the refrigerant amount adjustment container 14 is set to have a volume sufficient to collect excess refrigerant. The temperature of the main pipe ₅₃ as a suction pipe is controlled to a temperature equal to the saturation pressure inside the refrigerant amount regulating container 14, so in order to obtain the suction gas temperature with the desired degree of superheating, the connecting pipe 15 is connected to the capillary tube 9a. It may be connected to an appropriate pressure position in the piping including the evaporator 11a. Therefore, a refrigerant amount adjusting container 14 is disposed in the main pipe 5 ₃ as a suction pipe of the compressor 2 so as to exchange heat with the refrigerant passing through the main pipe 5 ₃ , and the container 14 is connected to the capillary tube 9 a. By connecting the branch pipe 7a between the evaporators 11a via the connecting pipe 15, it is possible to eliminate the inconvenience that unevaporated liquid refrigerant is sucked into the compressor as in the conventional system when two units are operated. That is, when unevaporated liquid refrigerant passes through the main pipe ₅₃ on the indoor unit side of the compressor 2, the refrigerant amount adjustment container 14 is cooled, and the refrigerant in the container 14 is condensed and liquefied, and is sent to the evaporators 11a and 11b. The surplus of the refrigerant that has been supplied in excess is collected into the container 14, and the inconvenience of unevaporated liquid refrigerant being sucked into the compressor 2 can be eliminated. As a result, damage to the compressor can be prevented, as well as an increase in voltage consumption of the compressor due to suction of liquid refrigerant, making it possible to perform highly reliable and highly efficient cooling operation. Further, the cooling device of the present invention does not include an expansion valve and is inexpensive, and has a highly reliable structure since there are no moving parts. In the above embodiment, a two-chamber type was described, but the same effect can be achieved even if the indoor unit incorporates three or more chambers. Furthermore, although the above embodiments have been described using a cooling device as an example, the present invention can be similarly applied to a heating and cooling device. As detailed above, according to the present invention, it is possible to provide a multi-room air conditioner that has a simple structure and can operate with high reliability and high efficiency.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional two-chamber cooling system;
The figure is a schematic diagram of an improved conventional two-chamber cooling system.
FIG. 3 is a schematic diagram of a two-chamber cooling device showing an embodiment of the present invention. 1 ...Outdoor unit, 2...Compressor, 3...Condenser (outdoor heat exchanger), 4...Refrigerant receiver, 5 ₁ ,
5 ₂ , 5 ₃ , 5 ₄ ... Main piping, 6a, 6b, 7a,
7b... Branch pipe, 8a, 8b... Solenoid valve, 9a, 9
b...capillary tube, 10a , 10b ...indoor unit, 11a, 11b...evaporator (indoor heat exchanger),
14... Refrigerant amount adjustment container, 15... Connection piping.

Claims (1)

[Scope of utility model registration request] An outdoor unit having a refrigerant compressor, an outdoor heat exchanger, and a plurality of branch pipes in which a refrigerant receiver, a solenoid valve, and a capillary tube are successively interposed from the heat exchanger side, and each branch pipe of this unit and the compressor. In a multi-room air conditioner, which is composed of a plurality of indoor units each having an indoor heat exchanger installed between the compressor and the indoor A refrigerant amount regulating container is provided in at least a portion of the piping extending toward the unit so as to surround the piping, and the container is connected to either one of the capillary tube and a branch pipe between the indoor unit. Multi-room air conditioner.