JPH03217771A - Air conditioner - Google Patents

Abstract

PURPOSE:To realize the control of a large capacity of refrigerant circulating amount inexpensively and control the flow amount of the refrigerant continuously by providing a bypass pipe with an opening and closing valve, bypassing an electronic expansion valve, in the part of the expansion valve of the electronic expansion valve. CONSTITUTION:An opening and closing valve (solenoid valve) 8 is provided in a bypass pipe provided in parallel to an electronic expansion valve 5 while the capacity of the opening and closing valve is the same as the capacity of said electronic expansion valve 5. The electronic expansion valve 5 and the opening and closing valve 8 are controlled by a controller 11 and when the circulating amount of refrigerant is smaller than the capacity of the electronic expansion valve 5, the opening and closing valve 8 is closed and the electronic expansion valve 5 is controlled. When the circulating amount of the refrigerant is so big that it exceeds the capacity of the electronic expansion valve 5, the opening and closing valve 8 is opened and the electronic expansion valve 5 is also controlled. The opening and closing valve 8 and the electronic expansion valve 1 are controlled by the controller 11 in such a manner whereby the circulating amount of refrigerant is controlled continuously from a small capacity to a big capacity. Further, the opening and closing valve 8 is very cheat compared with a case wherein the electronic control valve of a big capacity is employed and the same valve 8 can be used for controlling the circulating amount of refrigerant to a big capacity.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to an air conditioner.

(Example) Conventional technology The conventional technology for air conditioners is
There is an air conditioner as described in Japanese Patent No. 89, and this air conditioner is equipped with a refrigeration cycle configured by connecting a compressor, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger with piping. The throttle device is controlled to adjust the amount of refrigerant circulating in the refrigeration cycle.

(c) Problems to be Solved by the Invention In the air conditioner described above, a temperature-type expansion valve whose opening degree is controlled by temperature is used as the throttle device to control the amount of refrigerant circulation. When using such an expansion valve, since the valve opening degree is controlled based on temperature, there is a drawback that there is a large time delay in control and hunting occurs frequently. Another drawback is that the flow rate of the refrigerant cannot be controlled continuously and arbitrarily.

In the air conditioner described above, the refrigerant flow rate is continuously controlled.
In addition, it is also possible to use an electronic expansion valve that can be controlled arbitrarily, and the opening degree of the valve is controlled by the drive of a motor.In an attempt to increase the refrigerant flow rate controlled by this electronic expansion valve,
If a large-capacity electronic expansion valve is used, a large torque is required, and the cost [for example, a commonly used electronic expansion valve is around several thousand yen, and a large-capacity electronic expansion valve is about twice that amount, or even more. Due to the above reasons, it is difficult to use in practice.

In addition, if such an air conditioner is installed in a high-rise building, for example, a building with about 25 floors requires a height difference of up to 100 meters, but if the pressure drop of the liquid column during heating operation is large, the throttling device The drawback was that there was a lack of capacity and the system could not be operated. The use of electronic expansion valves in recent multi-type air conditioners for buildings has a height difference of 50%.
m is the limit at which normal control can be achieved.

The present invention provides an air conditioner that can realize large-capacity control of the refrigerant circulation amount at low cost and can continuously control the refrigerant flow rate.

(2) Means for Solving the Problems In order to solve the problems of the prior art described above, the present invention provides a compressor, a condenser, an electronic expansion valve that can continuously control the amount of refrigerant circulated, and an evaporator. In an air conditioner having a refrigeration cycle configured by connecting each with piping,
The electronic expansion valve section is provided with a bypass pipe with an on-off valve that bypasses the electronic expansion valve.

(E) Effect In the air conditioner according to the present invention, when the refrigerant circulation amount is a small amount less than the capacity of the electronic expansion valve, the on-off valve is closed, the electronic expansion valve is controlled, and the refrigerant circulation amount is When the capacity exceeds the capacity of the electronic expansion valve,
When the on-off valve is opened, the electronic expansion valve is fully controlled and the refrigerant circulation amount is continuously controlled from small capacity to large capacity.

(F) Embodiment An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a refrigerant circuit diagram of an air conditioner according to the present invention, which includes an outdoor unit (A) and an indoor unit (A).
B).

(1) is a compressor, <2) is an accumulator installed on the suction side of this compressor, <3) is a four-way valve that switches the refrigerant flow path depending on heating or cooling operation, and (4) is an outdoor heat source. exchanger, (5) is an electronic expansion valve [electric valve] that functions as a pressure reducing device, (6) is a receiver tank, and (7) is installed in the electronic expansion valve (5) section in parallel with this electronic expansion valve (5). The bypass pipe (8) is an on-off valve (relaxation valve) provided in this bypass pipe, and this on-off valve has a capacity equal to the electronic control valve (5).
) is the same as the capacity.

(9)<10) are an indoor heat exchanger and an electric valve provided in the indoor unit (B), respectively.

(11) is the opening degree of the electronic expansion valve (5) and the opening/closing valve (7).
) is a control device that controls the opening and closing of the

In the air conditioner of the present invention configured as described above, the electronic expansion valve (5) and the on-off valve (8) are controlled by the control device (11) as shown in FIG.

That is, when the refrigerant circulation amount is small, such as less than the capacity of the electronic expansion valve (5), the on-off valve (1) is closed and the electronic expansion valve (5) is controlled.

Furthermore, when the refrigerant circulation amount is large, such as when it exceeds the capacity of the electronic expansion valve (5), the on-off valve (1) is opened and the electronic expansion valve (5) is controlled. in this way,
The on-off valve (8) and the electronic expansion valve (1>) are connected to the control device (11).
), the refrigerant circulation amount can be continuously controlled from small to large capacity.

Furthermore, the on-off valve (8) costs about a few hundred yen, which is much cheaper than using a large-capacity electronic control valve (about a few thousand yen), and it is possible to increase the amount of refrigerant circulation. Easy to use to control.

FIG. 3 shows the main part of another embodiment of the present invention, and FIG. 4 shows the relationship between the valves controlled in this embodiment and the amount of refrigerant circulation.

In this way, a plurality of on-off valves (8) (15) having the same capacity as the electronic expansion valve (5) may be provided in parallel with the electronic expansion valve (5).In this case, the amount of refrigerant circulation to be controlled is It is approximately 1.5 times larger than that shown in FIG.

(G) Effects of the Invention As explained above, the air conditioner of the present invention has an on-off valve in the bypass pipe installed in parallel with the electronic expansion valve, so it is possible to control large-capacity refrigerant circulation. It is possible to provide an air conditioner that can be realized at low cost and that can continuously control the amount of refrigerant circulated.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram of an air conditioner according to the present invention, and FIG. 2 is a diagram showing the relationship between controlled valves and refrigerant circulation amount.
FIG. 3 is an explanatory diagram of the main parts of an air conditioner according to another embodiment of the present invention, and FIG. 4 is a line section showing the relationship between the valves controlled in the embodiment shown in FIG. 3 and the refrigerant circulation amount. . 1)...Compressor, (4)...Outdoor heat exchanger,
(5)...electronic expansion valve, (7)...bypass pipe,
(8)...On-off valve, (9)...Indoor heat exchanger, (15)...On-off valve.

Claims (1)

[Claims] (1) In an air conditioner having a refrigeration cycle configured by connecting a compressor, a condenser, an electronic expansion valve, and an evaporator, the electronic expansion valve section is equipped with an on-off valve that bypasses the electronic expansion valve. An air conditioner characterized by having a bypass pipe.