JPS638388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a conventional cycle configuration of a heat pump room air conditioner equipped with an outdoor heater that incorporates an outdoor heater on the outdoor heat exchange side.

In this Figure 1, 1 is a compressor, 2 is a four-way valve that switches the refrigerant flow path between cooling and heating, and 3
is an outdoor heat exchanger, 4 is a heating check valve, 5 is a heating pressure reducer, 6 is a cooling check valve, 7 is a cooling pressure reducer,
8 is an indoor heat exchanger, 9 is an accumulator that prevents the refrigerant from returning to the compressor 1, 10a is a refrigerant flow path during outdoor heating operation, and 10 is a heat source for heating when the room temperature drops. The outdoor heater 10, which is the outdoor heater used, is provided in the refrigerant flow path 10a during the outdoor heating operation. 11 is a three-way valve that switches the refrigerant flow path to the outdoor heat exchanger 3 or the outdoor heater 10. The heating and cooling pressure reducers 5 and 7 may be a capillary reach tube, an expansion valve, etc., and the heat source of the outdoor heater 10 may be a burner, a boiler, an electric heater, etc.

In the cycle configuration shown in Fig. 1, during cooling operation, the refrigerant flows as shown by the solid line arrow, drawing a Mollier diagram as shown by the solid line a in Fig. 2, and compressing A-B,
The cycle of condensation BC, depressurization CD, and evaporation DA is repeated, and the heat is discarded to the outside air in the outdoor heat exchanger 3 to cool the room. In addition, during outside air heat source heating operation, the refrigerant flows as shown by the broken line arrow, drawing a Mollier diagram as shown by the broken line b in Figure 2, and compressing A1-B.
1, Condensation B1-C1, Decompression C1-D1, Evaporation D1
- The cycle A1 is repeated, and the outdoor heat exchanger 3 pumps up heat from the outside air to heat the room. However, when the outside temperature is low, such as at night or in the middle of winter, the heating capacity decreases while the heating load increases, making it impossible to adequately heat the room. In this case, the three-way valve 11 is switched to allow the refrigerant to flow in the direction of the dashed-dotted line arrow, heated by the outdoor heater 10, and then circulated by the compressor 1 to the indoor heat exchanger 8, where the heat is radiated to provide heating. By doing so, it is possible to obtain a substantially constant heating capacity almost regardless of the outside temperature. In addition, in this cycle, since the outdoor heater 10 is a high-temperature heat source, there is no need to lower the refrigerant temperature on the low-pressure side too much, and as shown in FIG.
A Mollier diagram like this is sufficient, and the compression A2-B2,
Condensation B2-C2, reduced pressure C2-D2, evaporation D2-A
By repeating the cycle 2, the compressor input can be made very small.

The above cycle configuration has the following drawbacks.

In the cycle configuration shown in Fig. 1, during outdoor heating operation, the outdoor heat exchanger 3, through which no refrigerant flows, becomes the low-pressure side of the compressor 1, and its saturation temperature is higher than the outside air temperature, so liquid refrigerant accumulates inside, leading to cooling operation. During heating and outside air heat source heating operation, the outdoor heater 10 through which refrigerant does not flow becomes the high pressure side of the compressor 1, and its saturation temperature is higher than the outside air temperature, so liquid refrigerant accumulates inside. Product is outdoor heater 1
Due to reasons such as the internal volume being much larger than that of 0, the optimal amount of refrigerant to be filled during outdoor heating operation is approximately twice that of cooling operation or outside air heat source heating operation.

In this case, if a large amount of refrigerant is sealed during outdoor heating operation, a large amount of refrigerant will remain during cooling operation and outdoor air heat source heating operation, causing liquid to return to the compressor 1, which will impair the reliability of the compressor 1. There is a problem.

On the other hand, if a small amount of refrigerant is sealed for cooling operation or air heat source heating operation, the outdoor heater 10 will be in a superheated state due to the small amount of refrigerant present during outdoor heating operation, and the compressor 1 will be in a superheated state during steady operation. When the suction temperature of the compressor 1 becomes high and the motor of the compressor 1 burns out, or the power supply is cut off due to a power outage, etc., the refrigerant inside the outdoor heater 10 is heated by the heat capacity of the outdoor heater 10 itself, and the temperature of the refrigerant reaches the heat-resistant temperature. There is a risk that the situation will be more than that.

The present invention eliminates the above-mentioned drawbacks of the prior art,
To provide a heat pump room air conditioner with an outdoor heater, which has a cycle configuration that allows stable and well-balanced cycle operation by keeping the same optimum amount of refrigerant in cooling operation, outside air heat source heating operation, and outdoor heating operation. is the purpose of this.

The feature of the heat pump room air conditioner equipped with an outdoor heater of the present invention is that the main refrigerant flow path having an outdoor heat exchanger and a pressure reducer for heating is bypassed to provide a refrigerant flow path during outdoor heating operation. A switching valve for switching the refrigerant to flow through the refrigerant flow path during the outdoor heating/heating operation is provided at a downstream side of the refrigerant flow path during the outdoor heating/heating operation at a branching portion from the main refrigerant flow path during the outdoor heating/heating operation. In a heat pump type room air conditioner equipped with an outdoor heater that has an outdoor heater installed in the refrigerant flow path during outdoor heating operation, cooling operation and outdoor air heat source heating are performed on the downstream side of the outdoor heater in the refrigerant flow path during outdoor heating operation. A heat pump room air conditioner equipped with an outdoor heater is provided with a refrigerant tank having an internal volume capable of storing surplus refrigerant during operation.

More specifically, a refrigerant flow path for outdoor heating and heating operation is provided by bypassing a main refrigerant flow path having an outdoor heat exchanger and a heating pressure reducer, and the main refrigerant flow path on the downstream side of the refrigerant flow path for outdoor heating and heating operation is provided. A switching valve for switching the refrigerant to flow through the refrigerant flow path during the outdoor heating and heating operation is provided at a branching portion with the refrigerant flow path during the outdoor heating and heating operation, and an outdoor heater is provided in the refrigerant flow path during the outdoor heating and heating operation. In a heat pump room air conditioner equipped with an outdoor heater, an internal volume that can store surplus refrigerant during cooling operation and outside air heat source heating operation is provided on the downstream side of the outdoor heater in the refrigerant flow path during outdoor heating operation. This is based on a cycle configuration that is equipped with a refrigerant tank that has a refrigerant tank, and a cycle that is equipped with a micro pressure reducer that has a much smaller pressure reducing effect than a heating pressure reducer on the upstream side of the outdoor heater is also configured as appropriate. This provides a heat pump room air conditioner with an outdoor heater that provides a sufficient self-control mechanism for the cycle.

The present invention will be explained below with reference to Examples.

FIG. 3 is a cycle configuration diagram of a heat pump room air conditioner equipped with an outdoor heater according to an embodiment of the present invention.

In FIG. 3, the same numbers as in FIG. 1 indicate the same parts, and the same arrows indicate the refrigerant flow paths in the same operation. And 10a is an outdoor heating operation refrigerant flow path that bypasses the main refrigerant flow path that has an outdoor heat exchanger 3 and a heating pressure reducer 5;
11 is a refrigerant flow path 10a during this outdoor heating operation.
12 is a three-way valve related to a switching valve that switches the refrigerant to flow through the refrigerant flow path 10a during outdoor heating operation during outdoor heating operation, at a branching part from the main refrigerant flow path on the downstream side of . Refrigerant flow path 1
0a, provided on the downstream side of the outdoor heater 10,
This refrigerant tank has an internal volume capable of storing surplus refrigerant during cooling operation and outside air heat source heating operation.

10a, a micro pressure reducer 13 is provided on the upstream side of the outdoor heater 10, and the pressure reduction effect is much smaller (for example, about 1/10) than that of the heating pressure reducer 5. By providing the refrigerant tank 12, the inside of the refrigerant tank 12 is filled with liquid refrigerant because the temperature is higher than the outdoor air temperature. As a result, by appropriately selecting the internal volume of the refrigerant tank, the refrigerant can be adjusted to suit the outdoor heating operation, which conventionally occurred due to the internal volume of the outdoor heat exchanger 3 being much larger than the internal volume of the outdoor heater 10. This solves the drawback of using too much refrigerant during cooling and outside air heat source heating operations when the refrigerant is filled in, and the imbalance in the amount of refrigerant charged can be adjusted. It can be operated in a well-balanced and stable manner.

FIG. 4 is a partial cycle configuration diagram showing another embodiment of the portion surrounded by the two-dot chain line in FIG.

In FIG. 4, the same numbers as in FIG. 3 indicate the same parts, and the same arrows indicate the refrigerant flow paths at the same slow rotation.

In this embodiment, the refrigerant flow path 1 during outdoor heating operation is
0a, a micro pressure reducer 1 is installed on the upstream side of the outdoor heater 10.
3 is provided, and the cycle control function that a pressure reducer generally has also makes the cycle more stable during outdoor heating operation under various operating conditions, including startup and load fluctuations. I can drive.

According to each of the embodiments described above, the refrigerant distribution state within the cycle can be maintained optimally during cooling operation, outside air heat source heating operation, and outdoor heating operation, and various operating conditions including startup, load fluctuation, etc. Even in this case, the cycle can be operated stably in a well-balanced manner, and a highly reliable cycle configuration can be achieved.

As explained in detail above, according to the present invention, the cycle configuration is provided in which the optimal amount of refrigerant is kept the same in cooling operation, outdoor air heat source heating operation, and outdoor heating operation, and the cycle can be operated stably in a well-balanced manner. We can provide a heat pump room air conditioner with an outdoor heater.

[Brief explanation of the drawing]

Figure 1 is a cycle configuration diagram of a conventional heat pump room air conditioner equipped with an outdoor heater.
FIG. 2 is a typical Mollier diagram during cooling operation, outside air heat source heating operation, and outdoor heating operation. FIG. 3 is a typical Mollier diagram of a heat pump room air conditioner with an outdoor heater according to an embodiment of the present invention. Cycle configuration diagram, FIG. 4 is a partial cycle configuration diagram showing another embodiment of the part surrounded by the two-dot chain line in FIG. 3...Outdoor heat exchanger, 10...Outdoor heater, 1
0a... Refrigerant flow path during outdoor heating operation, 12...
Refrigerant tank, 13...micro pressure reducer.

Claims (1)

[Claims] 1. A refrigerant flow path for outdoor heating and heating operation is provided by bypassing the main refrigerant flow path having an outdoor heat exchanger and a pressure reducer for heating, and a refrigerant flow path for outdoor heating and heating operation is provided on the downstream side of the refrigerant flow path for outdoor heating and heating operation. A switching valve for switching the refrigerant so that it flows through the refrigerant flow path during the outdoor heating operation is provided at the branching portion of the refrigerant flow path from the main refrigerant flow path during the outdoor heating operation. In a heat pump type room air conditioner equipped with an outdoor heater, surplus refrigerant during cooling operation and outside air heat source heating operation can be stored on the downstream side of the outdoor heater in the refrigerant flow path during outdoor heating operation. A heat pump type room air conditioner equipped with an outdoor heater, characterized in that it is equipped with a refrigerant tank having a large capacity. 2 Outdoor heating according to claim 1, wherein a micro pressure reducer having a much smaller pressure reducing effect than a heating pressure reducer is provided on the upstream side of the outdoor heater in the refrigerant flow path during outdoor heating operation. Heat pump room air conditioner with heater.