JPS633231B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a method for sequentially connecting a compressor, a four-way switching valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger using refrigerant piping. This invention relates to improvements in connected heat pump type air conditioners.

(Prior Art) The diameter of the refrigerant pipe disposed inside the air-refrigerant heat exchanger used in this type of heat pipe type air conditioner is generally selected in consideration of the following.

Flow pressure loss of refrigerant (this affects refrigeration capacity loss) Amount of refrigerant sealed (preferably as small as possible) Heat transfer characteristics Air ventilation resistance Other factors such as pipe mass productivity, formability, standardization, etc. Cooling In the case of a dedicated air conditioner, the refrigerant pipes installed inside the heat exchangers installed on both the indoor and outdoor sides are The outside has a narrow diameter,
It was normal for the indoor side to have a larger diameter.

This is to reduce the amount of refrigerant that accumulates in the outdoor heat exchanger, which serves as a condenser, during cooling, and to reduce the pressure loss of refrigerant flowing through the indoor heat exchanger, which serves as an evaporator.

Furthermore, in some cases, it has been common practice to make the pipes have the same diameter with emphasis on mass productivity, formability, standardization, etc.

On the other hand, considering the climate of Japan, there is a strong demand for a dual-purpose air conditioning system rather than a cooling-only type, and recently, small home heat pump type air conditioners that meet this requirement have become increasingly popular.

In this type of air conditioner, more heating capacity than cooling capacity is required among the cooling and heating capacities.

However, even in such a dual-use heat pump type air conditioner, based on the design concept of the cooling-only type described above, the diameter of the refrigerant pipe of the heat exchanger is set to a large diameter on the indoor side and a small diameter on the outdoor side. Or,
Alternatively, it was common practice to make both the same diameter.

(Problem to be solved by the invention) As described above, since the diameter of the refrigerant pipe is determined based on the cooling operation, even if the refrigerant pipe exhibits sufficient capacity during the cooling operation, the capacity may be insufficient during the heating operation. To compensate for this deficiency, the air volume of the indoor heat exchanger was increased during heating operation. However, as the air volume increases, the temperature of the indoor air outlet becomes lower, causing discomfort to the user. Therefore, it was necessary to attach a heater and provide means for heating with the heater.

In view of the above, the present invention determines the diameter of the refrigerant pipe based on the heating operation, thereby exhibiting sufficient performance during heating operation, which requires particularly high performance,
Moreover, the object is to provide something that not only does not cause much trouble during cooling operation, but also does not lead to an increase in size and material costs.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a heat pump in which a compressor, a four-way switching valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger are sequentially connected through refrigerant piping. In the type air conditioner, the diameter of the refrigerant pipe of the outdoor heat exchanger is made larger than the diameter of the refrigerant pipe of the indoor heat exchanger.

(Function) Therefore, the diameter of the refrigerant pipe of the indoor heat exchanger that serves as a condenser during heating is made small, and the diameter of the refrigerant pipe of the outdoor heat exchanger that serves as an evaporator is made large. By doing so, the pressure loss of the refrigerant flowing through the refrigerant pipe of the outdoor heat exchanger, which serves as the evaporator, which has a large effect on the flow pressure loss of the refrigerant, is reduced.
This increases the capacity during heating operation.

In addition, in the case of this configuration, since the diameter of the refrigerant pipe of the indoor heat exchanger is made small,
During cooling, this indoor heat exchanger becomes an evaporator,
Since the flow pressure loss has a large effect on the evaporator, this loss increases, but since the capacity is generally large to begin with, it does not cause much trouble.

(Example) Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an embodiment of a heat pump type air conditioner according to the present invention, in which a compressor 1 is connected to an outdoor heat exchanger 3 via a four-way switching valve 2,
This heat exchanger 3 is connected to an indoor heat exchanger 5 via an expansion device 4, and this heat exchanger 5 is connected to a compressor 1 via the four-way switching valve 2.

In the figure, the cooling operation is performed by circulating in the direction of the solid line arrow, and the heating operation is performed by circulating in the direction of the broken line arrow.

In this case, a specific example of the heat exchangers 3 and 5 on the outdoor side and the indoor side is shown in FIG. 2. As shown in FIG. Consisting of In the present invention,
The diameter D of this refrigerant pipe 7 is such that the indoor side is narrower.
It is designed so that the outside side is thicker.

In this way, the diameter of the refrigerant pipe of the indoor heat exchanger that serves as a condenser during heating is made small, and
By increasing the diameter of the refrigerant pipe of the outdoor heat exchanger that serves as the evaporator, the pressure loss of the refrigerant flowing through the refrigerant pipe of the outdoor heat exchanger, which has a particularly large effect, can be reduced. This is designed to increase the capacity during heating operation.

For example, the diameter of the refrigerant pipe 7 of the outdoor heat exchanger 3 is 8.0Φ, and the diameter of the refrigerant pipe 7 of the indoor heat exchanger 5 is 8.0Φ.
The heating capacity when the diameter is 9.52Φ is approximately
3800Kcal/h, but on the contrary, the diameter of the refrigerant pipe 7 of the outdoor heat exchanger 3 is
When the diameter of the refrigerant pipe 7 of the indoor heat exchanger 5 is 8.0Φ, the heating capacity is approximately 3950Kcal/h.
Therefore, the heating capacity can be improved without increasing the material cost, and the diameters of the refrigerant pipes 7 of the outdoor and indoor heat exchangers 3 and 5 can be made the same.
The heating capacity when 9.52Φ is approximately 4000 Kcal/h, whereas the diameter of the refrigerant pipe 7 of the outdoor heat exchanger 3 is 10.0Φ, and the diameter of the refrigerant pipe 7 of the indoor heat exchanger 5 is The heating capacity when 9.52Φ is approximately
4300Kcal/h, heating capacity can be improved without significantly increasing material costs.

In this case, due to the small diameter of the refrigerant pipe in the indoor heat exchanger, there will be a large flow pressure loss during cooling operation, but this is a particular problem since cooling can achieve more capacity than heating. (The reason why the heating system cannot reach its full potential during heating is because the amount of heat absorbed from the outside air is small.) In addition, if a problem occurs, in order to reduce the ventilation resistance of the heat exchanger, measures such as increasing the pipe pitch of the refrigerant pipes or increasing the air volume on the indoor side (air volume on the indoor side during cooling) can be used. Increasing the airflow temperature will raise the indoor air temperature, but unlike heating, the feeling of airflow increases comfort.)

Therefore, as a result, it is possible to improve the heating characteristics without a significant increase in material costs, and this improvement in characteristics makes it easier to match the cooling/heating capacity ratio to the required load. Since auxiliary heating using a heater or the like is not required as in the conventional case, it is possible to reduce costs and improve safety.

〔Effect of the invention〕

According to the present invention, the flow pressure loss of the refrigerant is lower during heating operation than during cooling operation, so that sufficient performance can be demonstrated during heating operation, and heat pump type air that eliminates the need for auxiliary heating using a heater etc. You can get a harmonizer.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing a useful heat pump type air conditioner to which the present invention is applied, and Fig. 2 is an explanation showing an outline of each indoor and outdoor heat exchanger used in this air conditioner. It is a diagram. 1... Compressor, 2... Four-way switching valve, 3... Outdoor heat exchanger, 4... Expansion device, 5... Indoor heat exchanger, 7... Refrigerant pipe.

Claims (1)

[Claims] 1. In a heat pump air conditioner in which a compressor, a four-way switching valve, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger are sequentially connected by refrigerant piping, the diameter of the refrigerant pipe of the outdoor heat exchanger is , a heat pump type air conditioner characterized in that the diameter is larger than the diameter of the refrigerant pipe of the indoor heat exchanger.