JPS62125265A - 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 [Technical Field of the Invention] The present invention relates to a multi-type air conditioner consisting of an outdoor unit and a plurality of indoor units.

[Technical background of the invention]

A conventional air conditioner of this type is shown in FIG.

In FIG. 3, 0 is an outdoor unit, H is an intermediate unit, and A, B, and C are indoor units.

1 is a compressor, this compressor 1, a four-way valve 21. An outdoor heat exchanger 3, a parallel body of a heating expansion valve 4 and a check valve 5, a liquid tank 6, a parallel body of indoor heat exchangers 7a, 7b, and 7c, an accumulator 8, etc. are successively connected to form a heat pump type refrigeration cycle. It consists of

Then, the liquid-side on-off valve (l-off-off valve) 12a and the cooling capillary tube 13a are sequentially inserted into the liquid-side refrigerant branch pipe 11a of the indoor heat exchanger 7a, and the liquid-side refrigerant branch pipe 11b of the indoor heat exchanger 7b is connected in sequence. Sequentially insert the on-off valve (electromagnetic on-off valve) 12b and the cooling capillary tube 13b, and sequentially connect the liquid-side on-off valve (electromagnetic on-off valve) 12C and the cooling capillary tube 13C to the liquid-side refrigerant branch pipe 110 of the indoor heat exchanger 7C. It is inserted and connected. In addition, a gas side on-off valve (electromagnetic on-off valve) 15a is inserted into the gas-side refrigerant branch pipe 14a of the indoor heat exchanger 7a, and a gas-side on-off valve (electromagnetic on-off valve) 15b is inserted into the gas-side refrigerant branch pipe 14b of the indoor heat exchanger 7b. A gas-side on-off valve (electromagnetic on-off valve) 15C is inserted into the gas-side refrigerant branch pipe 14G of the indoor heat exchanger IC.

Furthermore, the part side refrigerant branch pipe 11a in the intermediate unit H
, 11b, 11c and each cooling capillary tube, one end of the refrigerant recovery piping 20 is connected, and the other end of this refrigerant recovery piping 20 is connected to the outdoor heat exchanger 2 in the outdoor unit O. and the heating expansion valve 4. In the refrigerant recovery pipe 20, a resistor 21a is provided at a portion communicating with the part side refrigerant branch pipe 11a.
and the check valve 22a are sequentially inserted and connected, and the part side refrigerant branch pipe 11b is
A resistor 21b and a check valve 22b are sequentially inserted into a portion communicating with the refrigerant branch pipe 11c, and a resistor 21c and a check valve 22c are sequentially inserted into a portion communicating with the part side refrigerant branch pipe 11c.

Note that indoor units A, B, and C each have their own indoor temperature (
or suction air temperature) is equipped with a thermostat. Moreover, the illustrated solid line indicates the refrigerant flow direction during the cooling operation, and the illustrated broken line arrow indicates the refrigerant flow direction during the heating operation due to the switching operation of the four-way valve 2.

That is, in such an air conditioner, when all the indoor units are in the cooling operation state, for example, when the temperature of the room in which indoor unit 8 is installed drops to a set value, the liquid on-off valve 12a and the gas side on-off switch are turned off. The valve 15a is opened to block the refrigerant from flowing into the indoor heat exchanger 7a.

As a result of this cooling operation interruption, the indoor temperature decreases to the set value (
(including the differential), the liquid state on-off valve 12a and the gas-side on-off valve 15a are opened, the refrigerant flows into the indoor heat exchanger 1a, and the cooling operation is restarted.

Also, when all indoor units are in the @ room operation state,
For example, when the temperature of the room in which the indoor unit A is installed rises to a set value, the liquid on-off valve 12a and the gas-side on-off valve 15a are closed in the same manner as described above, and the flow of refrigerant to the indoor heat exchanger 7a is blocked. .

When the indoor temperature returns to the set value (including the differential) due to the interruption of the heating operation, the liquid on-off valve 12a and the gas-side on-off valve 15a are opened.

It is opened, the refrigerant flows into the indoor heat exchanger 1a, and the heating operation is restarted.

By the way, when the heating operation of the indoor unit A is interrupted, the flow of refrigerant to the indoor heat exchanger 7a is stopped.
Indoor heat exchanger 7a and refrigerant branch pipe 11a.

The temperature of 14a decreases to the same level as the room temperature. Then, the indoor heat exchanger 7a and the refrigerant branch pipes 11a, 14a
The refrigerant remaining inside condenses and the pressure of the refrigerant decreases to the saturated vapor pressure corresponding to the internal humidity.

When the pressure decreases in this way, the liquid on-off valve 12
The refrigerant enters the indoor heat exchanger 7a side little by little through the small gap between the gas side on-off valve 15a and the indoor heat exchanger 1a and the refrigerant branch pipe 11a.
, accumulates in 14a. As refrigerant accumulates, the amount of refrigerant circulating through other indoor heat exchangers becomes insufficient.
The refrigeration cycle becomes unstable, making it difficult to perform proper heating operations, and further adversely affecting the lifespan of the refrigeration equipment.

Therefore, when the heating operation of the indoor unit A is interrupted (or stopped), the indoor heat exchanger 7a and the refrigerant branch pipe 11a,
The refrigerant remaining in the refrigerant 14a is recovered to the low pressure side through the refrigerant recovery pipe 20, thereby solving the above-mentioned inconvenience. In addition, indoor unit B.

The refrigerant is recovered in the same way when the heating operation of the heating system C is interrupted (or stopped).

[Problems with background technology]

However, the outdoor unit O is usually installed on the roof of a building, and the intermediate unit H is usually installed inside the building. Therefore, the length of the refrigerant pipe between the outdoor unit 0 and the intermediate unit H is 10 Tr.
The L1 length can be as long as 70 m, and the provision of the refrigerant recovery pipe 20 makes the installation work very complicated and expensive.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to enable stable operation of the refrigeration cycle without installing refrigerant recovery piping, which greatly simplifies installation work and significantly reduces installation costs. Our goal is to provide an excellent air conditioner that can.

(Summary of the Invention) The present invention provides an outdoor unit having a compressor, an outdoor heat exchanger, and a pressure reducing device, a plurality of indoor units having an indoor heat exchanger, the compressor, an outdoor heat exchanger, and a pressure reducing device. , a refrigeration cycle formed by sequentially communicating a parallel body of indoor heat exchangers, a liquid side opening/closing valve provided in a part side refrigerant branch pipe of each of the indoor heat exchangers, and a gas side refrigerant of each of the indoor heat exchangers. a gas-side on-off valve provided in the branch pipe; a means for closing the liquid-side on-off valve and the gas-side on-off valve corresponding to the indoor unit when the operation of each indoor unit is stopped or interrupted; and during heating operation;
It consists of a means to periodically open the liquid side on-off valve and the gas side on-off valve corresponding to the indoor unit whose operation has been interrupted or stopped. The refrigerant present in the indoor heat exchanger and refrigerant branch pipes is recovered to the low pressure side by periodically opening the liquid side on-off valve and the gas side on-off valve.

(Embodiment of the Invention) An embodiment of the invention will be described below with reference to the drawings. However, in the drawings, the same parts as in FIG. 3 are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIG. 1, the refrigerant recovery piping is removed. Then, refrigerant temperature sensors 2 (la, 20b, 20
Install c.

FIG. 2 shows the control circuit.

An outdoor controller 30 is provided in the outdoor unit O, and a compressor drive circuit 31 is connected to the outdoor controller 30.

Then, the compressor motor 1m is connected to the compressor drive circuit 31.

In the intermediate unit H, a multi-controller 40 is provided, and the multi-controller 40 includes the refrigerant temperature sensors 20a, 20b, 20c and the valve drive circuit 41.
a, 41b, 41c, 42a, 42b
, 42c.

Liquid side on-off valves 12a and 12b are provided in each valve drive circuit.
.

12c and gas side on-off valves 15a, 15b, 1
Connect 5c.

Indoor controllers 50a for indoor units A, B, and C,
50b, 50c are provided, and operation control units 51a, 51b, 51c and indoor temperature thermostats 52a, 52b, 52c are connected to these indoor controllers.

Then, external controller 30, multi-controller 4
0, indoor air conditioner 1 to rollers 50a, 50b, 50
interconnect c.

Next, the operation in the above configuration will be explained.

It is assumed that all indoor units are currently performing heating operation. At this time, the indoor controller 50a of the indoor unit A monitors the state of the indoor temperature thermostat 52a, and when the indoor temperature rises and reaches the set value, issues an operation interruption command to the multi-controller 40. When the multi-controller 40 is supplied with an operation interruption command from the indoor controller 50a, the multi-controller 40 turns on the liquid side on-off valve 1 in response to the command to interrupt operation.
2a and the gas side on-off valve 15a are closed. When the liquid side on-off valve 12a and the gas side on-off valve 15a are opened, the flow of refrigerant into the indoor heat exchanger 7a is stopped, and the heating operation of the indoor unit A is interrupted.

Thereafter, when the indoor temperature drops below the set value (including the differential) due to the interruption of operation, the indoor controller 50a issues an instruction to the multi-controller 40 to resume operation. When the multi-controller 40 is supplied with an operation restart command from the indoor controller 50a, the multi-controller 40 responds to the command by turning on the liquid side on-off valve 12a and the gas side on-off valve 15.
Open a. When the liquid side on-off valve 12a and the gas side on-off valve 15a are opened, the refrigerant flows into the indoor heat exchanger 1a, and the heating operation of the indoor unit A is restarted.

By the way, when the operation of the indoor unit A is interrupted, the multi-controller 40 uses an internal timer to count the elapsed time of the operation interruption, and when a predetermined period of time has elapsed since the operation interruption, the multi-controller 40 opens the liquid side on-off valve 12a and the gas side on-off valve 15a. urge When the liquid-side on-off valve 12a and the gas-side on-off valve 15a open, the high-pressure gas refrigerant that has passed through the four-way valve 2 flows into the gas-side refrigerant branch pipe 14a, and the gas-side refrigerant branch pipe 14a and the indoor heat exchanger 7a.

The refrigerant accumulated in the liquid refrigerant branch pipe 11a is pushed to the low pressure side. In this way, the refrigerant that is swept away is collected into the liquid tank 6. When the accumulated refrigerant is washed away, the temperature of the liquid refrigerant branch pipe 11a increases.

On the other hand, the multi-controller 40 monitors temperature changes in the liquid refrigerant branch pipe 11a using the temperature sensor 20a,
When the temperature change of the liquid refrigerant branch pipe 11a exceeds a certain level, the liquid side on-off valve 12a and the gas side on-off valve 15a are opened. In other words, refrigerant recovery ends. This refrigerant recovery is then repeated at predetermined time intervals.

Furthermore, even when the heating operation of not only indoor unit A but also indoor units B and C is interrupted, the multi-controller 40 opens the liquid side on-off valve and the gas side on-off valve corresponding to the indoor unit at predetermined intervals, and performs the same operation. Perform refrigerant recovery.

In this way, when heating operation of an indoor unit is interrupted (or stopped), the liquid on-off valve and the gas-side on-off valve corresponding to that indoor unit are opened at predetermined intervals to recover refrigerant. Stable operation of the refrigeration cycle is possible without causing a refrigerant shortage in the indoor unit. Therefore, proper heating operation can be performed at all times.

Further, it does not adversely affect the life of the refrigeration cycle equipment. In particular, since the conventional refrigerant recovery piping between outdoor unit 0 and intermediate unit H is not required, installation work can be greatly simplified, and the cost of installation work can be significantly reduced. be able to.

In the above embodiment, the end of refrigerant recovery is determined based on the temperature change of the liquid refrigerant branch pipe, but a certain period of time is determined in advance, and refrigerant recovery is ended when the certain period of time has elapsed. It's okay. In addition, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without changing the gist.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to perform stable operation of the refrigeration cycle without installing refrigerant recovery piping, which greatly simplifies the installation work, and the cost involved in the installation work. We can provide an excellent air conditioner that can significantly reduce

[Brief explanation of drawings]

Figure 1 is a diagram showing the configuration of a refrigeration cycle in an embodiment of the present invention, Figure 2 is a diagram showing the configuration of a control circuit in the same embodiment, and Figure 3 is a diagram showing the configuration of a refrigeration cycle in a conventional air conditioner. FIG. O...Outdoor unit, H...Intermediate unit, A, B
. C...Indoor unit, 7a, 7b, 7c...Indoor heat exchanger, 11a, 11b, 11cm...Liquid refrigerant branch pipe, 12a, 12b. 12c...liquid side on-off valve, 14a, 14b, 1
4c...Gas side refrigerant branch pipe, 15a, 15b,
15c...Gas side on/off valve, 40...Multi controller.

Claims (1)

[Claims] An outdoor unit having a compressor, an outdoor heat exchanger, a pressure reduction device, a plurality of indoor units having an indoor heat exchanger, and a parallel body of the compressor, outdoor heat exchanger, pressure reduction device, and each indoor heat exchanger, etc. A refrigeration cycle connected in sequence, a liquid-side on-off valve provided in the liquid-side refrigerant branch pipe of each of the indoor heat exchangers, a gas-side on-off valve provided in the gas-side refrigerant branch pipe of each of the indoor heat exchangers, and the A means for closing the liquid side on-off valve and gas side on-off valve corresponding to the indoor unit when the operation of each indoor unit is interrupted or stopped, and corresponding to the indoor unit whose operation is interrupted or stopped during heating operation. An air conditioner characterized by comprising means for periodically opening a liquid side on-off valve and a gas side on-off valve.