JPH0668423B2 - Heat pump type air conditioner - Google Patents

Description

The present invention relates to a heat pump type multi-chamber air conditioner in which a plurality of indoor units are connected to a single outdoor unit having a pole-changing compressor.

(B) Conventional technology Japanese Patent Publication No. 53-21134 proposes a device that prevents a rise in high pressure by bypassing part of the gas discharged from the compressor to the low pressure side when an overload occurs during heating and cooling operation. ing.

Also, when changing the number of poles of the pole-changing compressor, the pole-changing compressor is temporarily stopped to prevent the compressor motor from being damaged, and the discharge of the compressor is easily restarted. An apparatus in which a part of gas is bypassed to the low pressure side is disclosed in Japanese Patent Publication No. 61-2854.

(C) Problems to be solved by the invention In a heat pump type multi-room air conditioner equipped with a pole-changing compressor, in addition to the high load measures and the compressor protection measures as described above, the following problems It is also necessary to take measures for the points.

That is, when the defrosting operation is performed by one indoor unit, the capacity of the indoor heat exchanger is halved as compared with the case where it is performed by two indoor units, so the refrigerant circulation amount is reduced, and the outdoor heat exchanger is completely It has a problem that it is not defrosted.

Further, it is necessary to change the bypass amount for the above-mentioned measures against high load and the bypass amount for the measures for protecting the compressor.

In view of such a problem, the present invention performs three types of bypass control for taking measures against high load, compressor protection, and defrosting with two solenoid valves and changing the bypass amount. A heat pump type air conditioner is provided.

(D) Means for Solving the Problems The present invention relates to a heat pump type air conditioner, in which a discharge pipe and a suction pipe of a compressor are connected by a first bypass pipe, and the discharge pipe side is connected to the first bypass pipe. Further, a first valve and a first capillary tube that are opened during overload operation and switching of the number of poles of the compressor are sequentially provided, and a second bypass tube is connected in parallel with the capillary tube to connect to the second bypass tube. A check valve and a second valve that opens when switching the number of poles of the compressor are sequentially provided from the first valve side, and one end of the second capillary tube is connected to the pipe that is the refrigerant outlet side of the outdoor heat exchanger during the defrost cycle. And the other end of the capillary tube is connected between the check valve and the second valve.

(E) Action When the air conditioner becomes overloaded or the indoor heat exchanger begins to freeze during the air conditioner operation, the first valve opens and some of the refrigerant discharged from the pole-changing compressor becomes It is bypassed to the suction side of the compressor through the bypass pipe 1. At this time, the bypass amount is determined by the first capillary tube so as to suppress the increase in the high pressure due to the overload operation and to promote the increase in the low pressure for preventing the freezing.

Further, the number-of-poles conversion compressor is operated in four stations when one indoor unit is used and in two stations when two indoor units are operated to perform cooling / heating operation. When the number of operating indoor units changes and the number of poles is switched during such operation, the compressor is stopped and the first and second valves are opened, so that part of the refrigerant discharged from the compressor is the first. The valve, the check valve, and the second valve are sequentially passed to promptly bypass the suction side of the compressor. By this bypass, the high and low pressures are instantly balanced and the compressor is easily started.

Also, when frost forms on the outdoor heat exchanger while one indoor unit is in heating operation, the four-way switching valve switches to perform defrosting operation, but the indoor heat exchanger and outdoor heat exchange for one indoor unit are performed. Due to the unbalanced capacity of the heat exchanger, the liquid refrigerant will accumulate in the outdoor heat exchanger. However, at the same time as the start of defrosting, the second valve is opened and the liquid refrigerant in the outdoor heat exchanger is guided to the suction side of the compressor through the second capillary tube and the second valve sequentially. There is almost no accumulation of the refrigerant, and the high-temperature discharge gas refrigerant from the compressor flows into the entire outdoor heat exchanger to be completely defrosted.

(F) Example When an example of the present invention is described with reference to the drawings, (1) is 2
Number of poles conversion type compressor that can be switched between 4 poles and 4 poles, (2) four-way switching valve that switches between cooling (defrosting) cycle and heating cycle, (3) outdoor heat exchanger, (4) for cooling and heating Expansion valve, (5)
Is a check valve, (6) is a cooling capillary tube, (7) is a refrigerant adjustment container,
(8) is a gas-liquid separator, (9) straddles the discharge pipe (10) and the suction pipe (11) of the compressor (1), and prevents freezing during overload operation from the discharge pipe (10) side. Time and the first valve that opens when switching the number of poles of the compressor (1)
A first bypass pipe in which (12) and a first capillary tube (13) are sequentially provided, and (14) is connected in parallel with this capillary tube (13) and is connected to the first valve (1
From the 2) side, a second bypass pipe in which a check valve (15) and a second valve (16) that opens when the number of poles of the compressor (1) is switched are sequentially provided, and (17) has one end during a defrost cycle. A second capillary tube having the other end connected between the check valve (15) and the second valve (16) to the pipe (18) on the refrigerant outlet side of the outdoor heat exchanger (3). The device is built into one outdoor unit (19).

(20a) (20b) are cooling on / off valves (21a) (21b) and check valves (22
a) (22b), cooling capillaries (23a) (23b), heating on-off valve (24a)
(24b), check valves (25a) (25b), indoor heat exchangers (26a) (26b),
An indoor unit that incorporates a third capillary tube (27a) (27b) that bypasses the heating on-off valves (24a) (24b) and the indoor heat exchangers (26a) (26b). ) Is connected in parallel.

Next, the operation of the present invention will be described. Both indoor units (20
a) Open / close valves for heating (24a) (24b) during simultaneous heating operation of (20b)
Is opened, the four-way switching valve (2) is set to the solid line state, the compressor (1) is started with two poles, and the refrigerant discharged from the compressor (1) is the four-way switching valve (2) -indoor heat. Exchanger (26a) (26b)
-Opening / closing valve for heating (24a) (24b) -Check valve (25a) (25b) -Refrigerant control container (7) -Expansion valve (4) -Outdoor heat exchanger (3) -Four-way switching valve
(2) -A gas-liquid separator (8) -a compressor (1) and a two-chamber heating cycle are formed.

If an overload occurs during such two-room heating operation, the compressor
The first valve (12) is opened by detecting the discharge gas pressure of (1), and a part of the refrigerant discharged from the compressor (1) is discharged to the first capillary tube (13).
Since it is bypassed to the suction pipe (11) through the first bypass pipe (9) while the flow rate is controlled by, the rise of the high pressure is suppressed.

Further, when the heating operation of one indoor unit (20b) is stopped and the operation is switched to the independent operation only by the other indoor unit (20a), the compressor (1) is temporarily stopped and the first and second valves ( 1
2) When the (16) is opened and a part of the refrigerant discharged from the compressor (1) is passed through the first valve (12), the check valve (15) and the second valve (16) in this order, the suction pipe. Since it is quickly bypassed to (11), the high and low pressures are instantly balanced and the compressor (1) is easily started with 4 poles.

During such a single room heating operation, the heating on-off valve (24b) of one indoor unit (20b) is closed, but this indoor unit (20b)
Since the gas refrigerant distributed to the side bypasses the indoor heat exchanger (26b) and the heating on-off valve (24b) by the third capillary tube (27b), the amount of liquid refrigerant accumulated in this indoor heat exchanger (26b) is Since the amount of heat becomes small and the refrigerant does not flow to the indoor heat exchanger (26b), even if only the fan of this indoor unit (20b) is operated to circulate the indoor air, the high pressure will decrease due to the heat exchange. The heating capacity of the other indoor unit (20a) in operation does not decrease.

Then, when the outdoor heat exchanger is frosted due to a decrease in outdoor temperature during the one-room heating operation, the four-way switching valve (2) is switched to the broken line state and the second valve (16) is opened, so that the compressor (1) is disconnected. The discharged refrigerant is a four-way switching valve (2) -outdoor heat exchanger (3) -expansion valve (4),
Check valve (5), cooling capillary tube (6) -refrigerant adjusting container (7) -cooling on-off valve (21a) -check valve (22a) -cooling capillary tube (23a) -indoor heat exchanger (26a) -Four-way switching valve (2) -Gas-liquid separator (8) -Compressor (1) circulates the defrost cycle and the capacity of the outdoor heat exchanger (3) and the indoor heat exchanger (26a) The liquid refrigerant that accumulates in the outdoor heat exchanger (3) due to the unbalance of
Since it is introduced into the suction side of the compressor (1) through the capillary tube (17) and the second valve (16) in sequence, there is almost no accumulation of liquid refrigerant, and all of the inside of the outdoor heat exchanger (3) The hot discharge gas refrigerant from the compressor (1) flows and the outdoor heat exchanger (3) is completely defrosted.

Further, the refrigerant flow during the cooling operation is similar to the above-mentioned defrost cycle, so its explanation is omitted.However, when the cooling load is small, the indoor heat exchanger (26a) acting as an evaporator freezes. In order to prevent this, the temperature of the indoor heat exchanger (26a) is detected and the first valve (12) is opened to raise the temperature and pressure of the indoor heat exchanger (26a).

(G) Effect of the Invention According to the present invention, measures against high load during cooling operation, protection measures against the compressor during switching of the number of poles, and capacities of the outdoor heat exchanger and the indoor heat exchanger are unbalanced. Countermeasures against defrosting during operation can be easily performed by opening / closing operations of two solenoid valves and selecting a bypass amount by a capillary tube corresponding to each countermeasure.

[Brief description of drawings]

Drawing is a refrigerant circuit diagram of a heat pump type air conditioner showing an embodiment of the present invention. (1) …… Pole conversion compressor, (2) …… Four-way switching valve, (3)…
… Outdoor heat exchanger, (9) …… First bypass pipe, (10) ……
Discharge pipe, (11) …… Suction pipe, (12) …… First valve, (13) ……
First capillary tube, (14) ... Second bypass tube, (15) ... Check valve, (16) ... Second valve, (17) ... Second capillary tube.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kiyoshi Tamura Inventor Kiyoshi Tamura 180 Sakata, Oizumi-cho, Gunma Prefecture Tokyo Sanyo Electric Co., Ltd. (56) Bibliography 61-58468 (JP, U) 59-38657 (JP, U) Actual development Sho 48-6651 (JP, U)

Claims (1)

[Claims] Claim: What is claimed is: 1. A four-way switching system in which one outdoor unit having a pole change compressor, a four-way switching valve and an outdoor heat exchanger is connected to a plurality of indoor units having an indoor heat exchanger. In a heat pump type air conditioner in which a cooling (defrosting) cycle and a heating cycle are formed by switching valves, a discharge pipe and a suction pipe of a compressor are connected by a first bypass pipe. The bypass pipe is provided with a first valve and a first capillary pipe which are opened from the discharge pipe side at the time of overload operation and when the number of poles of the compressor is switched, and a second bypass pipe is connected in parallel with this capillary pipe. A check valve and a second valve that opens when switching the number of poles of the compressor are sequentially provided on the second bypass pipe from the first valve side, and the second bypass pipe serves as a refrigerant outlet side of the outdoor heat exchanger during the defrost cycle. The one end of the second capillary tube and the other end of the capillary tube are connected to the check valve. The heat pump type air conditioner, characterized in that connected between the second valve.