JPH031587B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the improvement of a heat pump type separate type heating machine, and more specifically, when inspecting or repairing the heating machine, the refrigerant charged in the refrigerant circulation circuit is charged in advance to the outdoor unit. Concerning measures to ensure and facilitate pump-down for recovery into outdoor heat exchangers and liquid receivers.

(Prior art) Generally, when inspecting or repairing a separate air conditioner, the pump is pumped down in advance to recover the charged refrigerant to the outdoor unit, thereby preventing loss of refrigerant and ensuring work safety. It is preferable to secure it. However, in a heat pump type separate type heater, it is difficult to pump down the circuit as it is. That is,
In air conditioners and air conditioners, the refrigerant circulation cycle is operated as a cooling cycle, and by closing the refrigerant piping between the outdoor heat exchanger and the indoor heat exchanger with a liquid shutoff valve, the outdoor heat exchanger can be used as a condenser. It is possible to store the refrigerant charged in the refrigerant circulation circuit in the outdoor heat exchanger, recover it, and pump it down (for example, Utility Model Publication No. 58-54609, Utility Model Application Publication No. 57-1982). (See Publication No. 160072, etc.) On the other hand, since heaters do not have a cooling cycle, it has been difficult to pump down the refrigerant to an outdoor heat exchanger or the like.

(Problem to be Solved by the Invention) Therefore, for example, by providing a four-way switching valve and making it possible to switch the refrigerant circulation circuit between the heating cycle and the cooling cycle, pump-down operation is possible, and the It is conceivable to recover the refrigerant charged in the refrigerant circulation circuit.

However, since the above concept is equipped with a four-way switching valve, an unnecessary cooling function is added to a device exclusively for heating operation, and the price is almost the same as that of an air-conditioner, so it cannot be used as a device exclusively for heating. The disadvantage is that the low cost of the product is compromised.

The present invention has been made in view of the above points, and its purpose is to provide a separate type heater,
To make it possible to perform pump-down reliably and easily at low cost without providing a four-way switching valve by partially changing the heating cycle to recover refrigerant to an outdoor unit.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention provides a solution for refrigerant in an outdoor unit having a compressor, an outdoor heat exchanger, and an accumulator, and an indoor unit having an indoor heat exchanger. A separate type heater with a circulation circuit is assumed. A gas shutoff valve installed in the gas pipe from the compressor to the indoor heat exchanger, and a liquid shutoff valve installed in the liquid pipe from the indoor heat exchanger to the outdoor heat exchanger, when the pump is down. Bypass means for communicating the upstream side of the gas shut-off valve of the gas pipe with the downstream side of the liquid shut-off valve of the liquid pipe is provided. Further, the accumulator is constructed with an internal volume greater than the amount of refrigerant charged, and at least one of the gas and liquid shutoff valves is constructed as a three-way valve having an excess port that communicates with the indoor heat exchanger when closed. Furthermore, a communication pipe is provided for communicating the upstream side of the accumulator with the surplus port of the liquid or gas shutoff valve when the pump is down.

(Function) Therefore, in the present invention, when pump-down is necessary, the liquid pipe and the gas pipe are closed by the liquid shut-off valve and the gas shut-off valve, and the bypass means closes the liquid pipe and the gas pipe on the upstream side of the gas shut-off valve in the gas pipe. The liquid pipe is connected to the downstream side of the liquid shutoff valve, so that the refrigerant immediately flows from the compressor to the outdoor heat exchanger, where it is cooled by the outdoor heat exchanger that acts as a condenser, liquefied, and collected in the accumulator. will be done.
In addition, the surplus port of the liquid shutoff valve or the gas shutoff valve communicates with the indoor heat exchanger and the upstream side of the accumulator via the communication pipe, so that the liquid refrigerant of the indoor heat exchanger flows through the surplus port of the shutoff valve. Then, it flows into the accumulator through the communication pipe and is collected.

In that case, the refrigerant flow path is a simple flow path with a partial modification of the heating cycle in which the refrigerant bypasses the indoor heat exchanger and immediately flows into the outdoor heat exchanger from the compressor, so the four-way switching valve It is not necessary to provide the device, and the device can be constructed at low cost. In addition, since the passage length is relatively short due to the simple configuration of the circulation system, and the refrigerant circulates smoothly, pumping down can be performed reliably and easily.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The drawing shows a refrigerant piping system of a separate type heater according to the present invention, where X is an outdoor unit, Y is an indoor unit, and the outdoor unit X has a compressor 1.
, an outdoor heat exchanger 2 that functions as an evaporator and has a blower fan 2a, a pressure reduction mechanism 3 consisting of a capillary tube, and an accumulator 4, while the indoor unit Y functions as a condenser. An indoor heat exchanger 5 having a blower fan 5a is built-in. Each of the above-mentioned devices 1 to 5 is connected to allow refrigerant circulation through refrigerant piping 6 . As shown, by circulating the heat through the indoor heat exchanger 5 to the outdoor heat exchanger 2, the amount of heat absorbed from the outside air by the outdoor heat exchanger 2 is repeatedly released into the indoor air by the indoor heat exchanger 5, and the indoor heat exchanger 5 is circulated to the outdoor heat exchanger 2. It is designed to provide heating.

In addition, 10 is a gas shutoff valve interposed in the middle of the gas pipe 6 from the compressor 1 to the indoor heat exchanger 5 in the outdoor unit A liquid shutoff valve provided on the upstream side of the pressure reducing mechanism 3 of the pipe 6, and each of the shutoff valves 10,
11, in addition to two ports 10a, 10b, 11a, and 11b located between the refrigerant pipes 6, a service port 10c as a redundant port,
The service ports 10c and 11c are respectively connected to ports 10b and 11 on the indoor heat exchanger 5 side when the refrigerant pipe 6 is closed.
b. However,
When installing the heater or replacing the refrigerant pipe 6, the gas pipe 6 and the liquid pipe 6 are closed by the gas shut-off valve 10 and the liquid shut-off valve 11, respectively, and the service port 11c of the liquid shut-off valve 11 is connected to the refrigerant cylinder, for example. By making a communication connection and opening the service port 10c of the gas shutoff valve 10 to the atmosphere, the air accumulated in the indoor heat exchanger 5 and the refrigerant pipe 6 communicating therewith is released to the outside air for air purging. .

Furthermore, 13 has one end connected to the compressor 1 and the gas shutoff valve 1.
0, and the other end is connected to the liquid pipe 6 between the pressure reducing mechanism 3 and the outdoor heat exchanger 2. A normally closed solenoid valve 14 for opening and closing the bypass passage 13 is interposed, and during defrosting operation of the outdoor heat exchanger 2, the solenoid valve 14 is opened to open the bypass passage 13, thereby shutting down the compressor 1. The refrigerant from the gas refrigerant flows through the bypass passage 13, bypasses the indoor heat exchanger 5, and circulates to the outdoor heat exchanger 2, thereby giving the heat of the gas refrigerant to the outdoor heat exchanger 2. It is designed to defrost the outdoor heat exchanger. When the pump is down, the solenoid valve 14 is opened to open the bypass passage 13, so that the gas pipe 6 on the downstream side of the compressor 1 and the upstream side of the gas shutoff valve 10 is connected to the downstream side of the liquid shutoff valve 11 and outside heat. A bypass means 15 is configured to communicate with the liquid pipe 6 on the upstream side of the exchanger 2.

The accumulator 4 is configured to have an internal volume larger than the amount of refrigerant charged in the refrigerant circulation circuit 7 so that it can accommodate all the refrigerant in the refrigerant circulation circuit 7 during pump down. Further, one end of a communication pipe 16 separately provided for pump down is connected to the refrigerant pipe 6 on the upstream side of the above-mentioned accumulator 4 and downstream of the outdoor heat exchanger 2, and the other end of the communication pipe 16 is connected to Either one of the gas shut-off valve 10 or the liquid shut-off valve 11 (in the figure, the gas shut-off valve 1
By connecting the other end to the surplus port 10c of the gas shut-off valve 10 when a pump-down request is made, the upstream side of the accumulator 4 is communicated with the gas shut-off valve 10 via the communication pipe 16. That's what I do. A check valve 17 is interposed in the middle of the communication pipe 16 to allow the refrigerant to flow from the gas shutoff valve 10 to the accumulator 4 and to prevent the refrigerant from flowing in the opposite direction.

Next, the pump-down procedure in the above embodiment will be explained. First, the other end of the communication pipe 16 is connected to the service port 10c of the gas shut-off valve 10, and then the gas shut-off valve 10 and the liquid shut-off valve 11 are closed to cut off the refrigerant flow between the outdoor and indoor units X and Y. . At this time, the service ports 10c and 11c of the shutoff valves 10 and 11 are connected to the ports 10b and 11b on the indoor heat exchanger 5 side, respectively, and the downstream end of the indoor heat exchanger 5 is connected to the service port 11c of the liquid shutoff valve 11. The upstream end thereof communicates with the upstream side of the accumulator 4 via the service port 10c of the gas shutoff valve 10 and the communication pipe 16.

Thereafter, the solenoid valve 14 is opened and the compressor 1 and outdoor fan 2a are operated. As a result, the gas refrigerant from the compressor 1 flows through the bypass passage 13 to the outdoor heat exchanger 2, liquefies through heat exchange with outside air in the outdoor heat exchanger 2, and accumulates in the accumulator 4. The liquid refrigerant in the indoor heat exchanger 5 passes through the service port 10c of the gas shutoff valve 10 and the communication pipe 16 and accumulates in the accumulator 4, and the pump-down ends when all the refrigerant is recovered.

At that time, the refrigerant distribution circuit during pump-down includes a circuit that directly distributes the refrigerant from the compressor 1 to the outdoor heat exchanger 2 via the bypass passage 13, and a circuit that distributes the liquid refrigerant from the indoor heat exchanger 5 through the communication pipe 16. Since it is configured with a circuit that returns to the accumulator 4, there is no need to provide a four-way switching valve, and the device can be constructed at low cost. Furthermore, since the circuit configuration is relatively simple, the refrigerant can flow smoothly without any hindrance, and the pump down can be performed reliably and easily.

Furthermore, since the gas shutoff valve 10, liquid shutoff valve 11, solenoid valve 14, and bypass passage 13 are already installed for air purge and defrosting operation, the accumulator 4 is configured in advance with an internal volume larger than the amount of refrigerant charged. In this case, only the communication pipe 16 needs to be additionally installed, and the device can be constructed at a lower cost.

In the above embodiment, both the gas shutoff valve 10 and the liquid shutoff valve 11 are three-way valves.
Only one of the closing valves may be a three-way valve. In this case, the communication pipe 16 may be connected to this three-way valve.

(Effects of the Invention) As explained above, according to the separate type heater of the present invention, when the pump is down, the refrigerant circulation circuit other than the indoor heat exchanger closed by the gas shut-off valve and the liquid shut-off valve is stopped from being compressed. The refrigerant is circulated through the outdoor heat exchanger, and the liquid refrigerant from the indoor heat exchanger is returned to the downstream side of the outdoor heat exchanger through an excess port and a communication pipe provided on one of the closing valves, thereby forming a refrigerant circulation circuit. Since the refrigerant is collected into an accumulator with an internal volume greater than the amount of refrigerant charged, there is no need to add a four-way selector valve, and pump-down can be done inexpensively, reliably, and easily with a simple circuit configuration. It is something that can be done.

[Brief explanation of the drawing]

The drawing is a refrigerant piping system diagram showing an embodiment of the present invention. X...Outdoor unit, Y...Indoor unit, 1
...Compressor, 2...Outdoor heat exchanger, 4...Accumulator, 5c...Indoor heat exchanger, 6...Refrigerant piping, 10...Gas closing valve, 11...Liquid closing valve, 1
0c, 11c...Service port, 13...Bypass passage, 14...Solenoid valve, 15...Bypass means, 16...Communication pipe.

Claims (1)

[Claims] 1 In a separate type heater in which a refrigerant circulation circuit 7 is formed by an outdoor unit X having a compressor 1, an outdoor heat exchanger 2, and an accumulator 4, and an indoor unit Y having an indoor heat exchanger 5, A gas shut-off valve 10 provided in the gas pipe 6 to the indoor heat exchanger 5, and a liquid stop valve 1 provided in the liquid pipe 6 from the indoor heat exchanger 5 to the outdoor heat exchanger 2.
1, and a bypass means 15 for communicating the upstream side of the gas shut-off valve 10 of the gas pipe 6 to the downstream side of the liquid shut-off valve 11 of the liquid pipe 6 when the pump is down, and the accumulator 4 is equipped with a At least one of the gas shutoff valve 10 and liquid shutoff valve 11 is configured as a three-way valve having an extra port 10c or 11c that communicates with the indoor heat exchanger 5 side when closed, and further has a pump down valve. At times, the upstream side of the accumulator 4 is connected to the surplus port 10c of the liquid or gas shutoff valve 10 or 11.
Or a separate type heating machine characterized by being equipped with a communication pipe 16 for communicating with 11c.