JPS6251391B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner equipped with a refrigerant heating device and a compression mechanism with variable capacity, and one of its purposes is to reduce electrical input during heating. It is something to do.

Conventionally, air conditioners have been known that heat a refrigerant using a refrigerant heater, circulate it through a compressor, heat the indoor area, and also perform cooling operation using the same compressor. The machine has the following drawbacks:

First, if you create and operate a cycle in which the compressor, indoor heat exchanger, pressure reducer, and refrigerant heater are connected in series using a compressor with the capacity required for cooling operation, the compression ratio of the compressor will be lower than the conventional one. It is almost the same as that of a heat pump cycle, and the electrical input is consumed almost equally during both cooling and heating. A portion of that electrical input is output as heating capacity, but due to mechanical losses and other factors, the electrical input to the compressor should be low.

In addition, there is a cycle in which the pressure reducer is omitted from the above cycle and the compression ratio is reduced to lower the compressor input;
In addition, when attempting to obtain heating capacity, the suction pressure increases, which increases the amount of refrigerant circulation and increases the pressure loss in the piping, resulting in the compression ratio not being reduced.
The compressor input will not decrease.

In order to solve the above-mentioned conventional problems, the present invention has the following features:
A variable-capacity compressor is used during cooling and heating, and during heating, the compressor power is reduced and the compression ratio is reduced, but the amount of refrigerant circulation is not increased, and the input to the compressor is lowered.

Hereinafter, the present invention will be described with reference to the accompanying drawings showing one embodiment thereof.

In FIG. 1, reference numeral 1 denotes an indoor unit, which is equipped with an indoor heat exchanger 2, an indoor fan 3, and the like. 4 is an outdoor unit, which includes a compressor 5 as a cooling circuit 5a;
The four-way valve 1 is arranged so that an outdoor heat exchanger 6 and a pressure reducer 7 are arranged in series, and a series circuit consisting of a refrigerant heater 9 as a heating circuit 8a is arranged in parallel with the indoor heat exchanger 2.
0 and are connected via a two-way valve 11. 12 is an outdoor fan, and 15 is a check valve.

In this embodiment, the refrigerant heater 9 is of a gas combustion type, and includes a refrigerant heating section 9a and a burner section 9.
It is broadly classified into b. Note that the arrows indicate the direction in which the refrigerant flows, the solid line is the cooling cycle, and the broken line is the heating cycle.

Next, FIG. 2 shows the control circuit. Here, the same structures as those described above are given the same numbers and the description thereof is omitted. Note that 13 is a power switch, and 14 is a heating/cooling switch, with C switching to cooling and H switching to heating. Further, the terminals F and S of the compressor 5 are connected so that the compressor 5 can be operated at full capacity when F is set, and operated at capacity control when set to S. V is a power supply, which is supplied from the indoor unit 1.

Next, the cooling operation of the air conditioner having the above configuration will be explained.

The air conditioning/heating selector switch 14 is closed to the C side, and the compressor 5 is operated at full capacity, and the outdoor fan 1 is closed.
2. The indoor fan 3 is energized, and the refrigerant discharged from the cooling compressor 5 is condensed through the four-way valve 10 through the outdoor heat exchanger 6, reduced in pressure by the pressure reducer 7, and evaporated in the indoor heat exchanger 2. It passes through the four-way valve 16 and is sucked into the compressor 5.

Next, heating operation will be explained.

The cooling/heating selector switch 14 is closed to the H side, the compressor 5 performs capacity control operation, and the four-way valve 1
0, the two-way valve 11, and the burner section 9b of the refrigerant heater are energized, and the burner is ignited. here,
The refrigerant discharged from the compressor 5 passes through the four-way valve 10, radiates heat in the indoor heat exchanger 2, enters the heating circuit 8a through the two-way valve 11, and absorbs heat in the refrigerant heating section 9a of the refrigerant heater 9. It is vaporized and sucked into the compressor 5. At this time, the refrigerant discharged from the compressor 5 is sucked into the compressor 5 without passing through the pressure reducing mechanism, so the suction pressure is higher than in a normal refrigeration cycle, and the compression ratio of the compressor is small. The input to the compressor 5 is small.

Therefore, since the compressor 5 with variable capacity control is used and the compression ratio is kept as low as possible during heating, the amount of refrigerant circulated by the compressor 5 during full capacity operation is reduced. Compared to using it sparingly, the electrical input for heating can be kept low.

Furthermore, if refrigerant heating operation is performed at full capacity without performing heating capacity control, the amount of refrigerant circulating will increase too much, resulting in a large pressure loss during the refrigeration cycle, increasing the compression ratio and increasing electrical input. It has been said that an increase in electrical input causes the compressor temperature to rise, resulting in failure due to overheating, but by performing capacity control operation, it is possible to prevent the compressor from overheating due to an increase in electrical input.

Further, the ability of the compressor 5 may be varied by a well-known structure such as one provided with a pole number conversion, frequency conversion, or ability adjustment mechanism, for example.

As is clear from the above embodiments, the air conditioner equipped with the refrigerant heating device of the present invention controls the operation so that the capacity of the compressor is small when the refrigerant heating device is activated, and the compression ratio is made as small as possible. Since the compressor input is reduced, the electrical input during heating can be kept low.

In addition, during refrigerant heating operation, the electrical input is reduced by capacity control operation, which prevents compressor overheating.
If the compressor can be controlled in stages (for example, by inverter control), it can follow temperature changes due to fluctuations in the heating amount of the heater, and failures due to heating can be prevented.

Furthermore, by controlling the amount of refrigerant circulation, the degree of superheating of the refrigerant at the compressor suction point can be set to an optimum value, and failures due to liquid compression etc. can be prevented.

Furthermore, since one compressor can be used for cooling and heating, space can be saved and the outdoor unit can be made more compact.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of an air conditioner equipped with a refrigerant heater according to an embodiment of the present invention, and FIG. 2 is a schematic electrical circuit diagram of the air conditioner. 2... Indoor heat exchanger, 5... Compressor, 6... Outdoor heat exchanger, 7... Pressure reducer, 9... Refrigerant heater,
10... Four-way valve, 11... Two-way valve, 15, 16...
…non-return valve.

Claims (1)

[Claims] 1 A refrigeration cycle is constructed by connecting a compressor equipped with a capacity variable means, an outdoor heat exchanger, a pressure reducer, and an indoor heat exchanger, and one end of the refrigeration cycle is connected to the indoor heat exchanger and the pressure reducer. A bypass circuit having a refrigerant heating device connected between the compressor and the other end connected to the suction side of the compressor is provided, and a valve device is provided in the bypass circuit for guiding the refrigerant that has passed through the indoor heat exchanger to the refrigerant heating device. . An air conditioner comprising a refrigerant heating device provided with a capacity control device that controls the capacity of the compressor when the refrigerant is guided to the refrigerant heating device by the valve device.