JPS5910539Y2 - air conditioner - Google Patents

Description

[Detailed description of the invention] The present invention is an air conditioner that enables cooling operation in winter. Specifically, the heat exchanger on the heat source side is an air heat exchanger, and a bypass circuit is provided to bypass this heat exchanger. The present invention relates to an air conditioner that has a high-pressure control valve installed in a bypass circuit to enable cooling operation in winter.

Generally, kitchens and the like in buildings that use heat loads need to be cooled even in the winter, and as described above, air conditioners have been provided that are equipped with a high-pressure control valve and can perform cooling operations in the winter.

That is, this air conditioner uses a high-pressure control valve as described above, and when the high-pressure pressure falls below a predetermined level during winter cooling, the high-pressure control valve is operated to bypass the air side heat exchanger to prevent a high pressure drop. This makes it possible to operate the air conditioner in the winter.

When the above cooling operation is stopped, the heat exchanger is cooled by the low-temperature outside air, so most of the refrigerant in the refrigerant piping system accumulates in the heat exchanger and is cooled to the outside air temperature. become.

Therefore, at startup, there is almost no liquid refrigerant in the liquid receiver, and the heat capacity of the heat exchanger is large, so the condensing pressure cannot be raised to the set value of the high pressure control valve, and as a result, the high pressure control valve The valve was activated, resulting in a circuit configuration in which only hot gas flowed to the liquid receiver, resulting in an abnormal drop in low pressure and the problem of the compressor stopping.

Although this problem can be solved by increasing the amount of refrigerant charged, another problem arises that increases the cost, and this is not a preferable solution to the above-mentioned problem.

The present invention was devised in view of the above-mentioned problems.The bypass circuit is provided with an on-off valve that closes the bypass circuit at the start of winter cooling operation, and hot gas is forced to flow into the air-side heat exchanger. The liquid refrigerant stored in the heat exchanger is caused to flow out, and the refrigerant is transferred to the liquid receiver, without increasing the amount of refrigerant charged or increasing the capacity of the liquid receiver. This solved the problems of the conventional method.

Embodiments of the present invention will be described below based on the drawings.

The drawing shows an air-cooled heat pump type air conditioner, in which 1 is a compressor, 2 is a four-way switching valve, 3 is an air side heat exchanger that serves as a heat source, 4 is a liquid receiver, and 5 is a user side. 6 is an accumulator, 7 is an expansion valve for cooling, 8 is a check valve installed in a bypass pipe 9 bypassing the expansion valve 7, 10 is an expansion valve for heating, 11 is this expansion valve 10
This is a check valve installed in the bypass pipe 12 that bypasses the flow.

The above-mentioned devices are connected to each other by refrigerant piping 13, and a fan connected to the water side heat exchanger 5 circulates the refrigerant as shown by the solid line arrow during cooling and as shown by the dotted line arrow during heating. A secondary air conditioner (not shown) such as a coil unit is used to perform cooling and heating, and the four-way switching valve 2 is connected to the air-side heat exchanger 3 to remove the heat. A bypass circuit 14 bypassing the exchanger 3 and reaching the liquid receiver 4 is provided, and a high pressure control valve 15 is interposed in the bypass circuit 14 to enable cooling operation in winter.

What is shown in the drawing is an air conditioner configured as described above, in which the bypass circuit 14 is connected to the bypass circuit 14 for a certain period of time (approximately 5 minutes) when starting the cooling operation in winter.
An electromagnetic on-off valve 16 is provided to close the valve.

The high-pressure control valve 15 closes when the high-pressure pressure is equal to or higher than a predetermined pressure (for example, 13 to 14 kg/crn'') during winter cooling operation, allowing the refrigerant to flow into the air-side heat exchanger 3, so that the high-pressure pressure becomes a predetermined pressure. When the temperature is below, the bypass circuit 14 is opened to bypass the hot gas to the liquid receiver 4 side, and during this bypass, the hot gas does not flow to the air side heat exchanger 3.

In addition, the on-off valve 16 is configured such that, for example, an outside air temperature thermometer is linked with an operation switch for cooling operation, so that it always closes when starting the cooling operation when the outside air temperature is low in winter, and also mainly uses a timer to close the operation switch for cooling operation. After a certain period of time (for example, 5
minutes), and when the winter cooling operation is started, most of the refrigerant is stored in the air-side heat exchanger 3 and the condensation pressure reaches the set value of the high-pressure control valve 15. Even if the temperature is not rising, the entire amount of hot gas from the compressor 1 flows into the air-side heat exchanger 3, and the inflow of this hot gas forces the liquid refrigerant stored in the air-side heat exchanger 3. The liquid is then flowed out into the liquid receiver 4.

Therefore, during startup, the low pressure does not drop abnormally and the startup can be performed reliably.

In the embodiment described above, the opening operation of the on-off valve 16 is as follows:
Although it is controlled by a timer, a detector may be provided to detect the amount of refrigerant stored in the receiver 4, and the opening operation may be performed when the amount of stored refrigerant exceeds a certain level.

Further, a pressure equalizing pipe 17 is provided between the upper part of the liquid receiver 4 and the accumulator 6, and an electromagnetic on-off valve 18 that opens in conjunction with the on-off valve 16 is provided in this pressure equalizing pipe 17, so that the bypass circuit 14 is closed at startup. On-off valve 1 of pressure equalizing pipe 17 along with on-off valve 16
By opening 8, the refrigerant stored in the air side heat exchanger 3 can flow out to the liquid receiver 4 more smoothly and quickly.

As described above, according to the present invention, although winter cooling operation can be performed, when the operation is stopped and then started, refrigerant is forced into the liquid receiver even if most of the refrigerant is stored in the air side heat exchanger. The inconvenience of operation stopping due to an abnormal drop in low-pressure pressure can be reliably solved, and cooling operation in winter can be improved without having to make the liquid receiver large-capacity and fill it with more refrigerant than necessary. This allows you to start up smoothly.

[Brief explanation of drawings]

The drawing is a refrigerant piping system diagram showing an embodiment of the present invention. 3...Air side heat exchanger, 14...Bypass circuit, 15...High pressure control valve, 16...
・Opening/closing valve.

Claims (1)

[Scope of utility model registration request] In an air conditioner that is equipped with an air-side heat exchanger and a bypass circuit that bypasses the heat exchanger, and in which a high-pressure control valve is interposed in the bypass circuit to enable winter cooling operation, the bypass circuit is configured to perform winter cooling operation. An air conditioner comprising an on-off valve that closes the bypass circuit when the air conditioner starts.