JPH0113976Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a multi-room air conditioning system in which a plurality of indoor units are provided in one outdoor unit. Conventionally, this type of air conditioning system connects one outdoor unit 1 and a plurality of indoor units 2 through gas refrigerant pipes 3 and liquid refrigerant pipes 4, as shown in Fig. 1. . The outdoor unit 1 includes a compressor 5, a four-way air conditioning switching valve 6, an outdoor heat exchanger 7, a check valve 8, a heating expansion valve 9, and a two-way solenoid that controls the flow of refrigerant to the indoor unit 2. It is equipped with a valve 10. The indoor units 2, 2 each include an indoor heat exchanger 11, a cooling expansion valve 12, and a check valve 13. Further, numeral 14 in the figure is an operating valve. In this air-conditioning/heating device, the refrigerant flows as shown by the solid arrow → during cooling and as shown by the broken arrow ⓓ during heating. In this heating and cooling system, an outdoor unit 1 and indoor units 2, 2 are connected in parallel, and in this case, this is done as follows. That is, the inside of the equipment of the indoor unit 2, the gas refrigerant pipe 3, and the liquid refrigerant pipe 4 are filled with air, and if they are simply connected as they are, air will enter the refrigerant circuit and mix with the refrigerant. As a result, the coefficient of performance decreases due to an increase in condensing pressure, and since moisture is contained in the air, freezing occurs during the refrigeration cycle due to moisture contamination, often causing problems such as clogging of the expansion valve. In order to avoid this, it is necessary to perform a public air purge (air expulsion) before completing the connection to replace the air contained in the piping system with refrigerant before starting operation. However, in the conventional one, the two-way solenoid valve 10 in the outdoor unit 1 is provided facing each pipe,
These transfer the refrigerant in the refrigerant circuit to the indoor units 2 and 2.
It flows to one or both of the following. Therefore, the two-way solenoid valve 10 opens and closes only when current flows through the normal operation switch ON, and the flow of refrigerant is closed when the valve is not in operation. Therefore, when performing an air purge, it is not possible to open or close the two-way solenoid valve 10 arbitrarily. The operating valve 14 provided on the outer panel of the outdoor unit 1 is closed when shipped from the factory, and is gradually opened during air purging to drive out the air inside the refrigerant pipes 3, 4 and the indoor units 2, 2, and then fully opened. It is used for driving. For this reason, conventionally, in order to perform air purge during installation work, the two-way solenoid valve 10 is temporarily energized to open the flow of refrigerant. However, when installing heating and cooling equipment in newly built homes, there are many cases where the power is not turned on. Further, even if a power source is available, temporarily turning on electricity is cumbersome and requires repair after the work is completed, which has the disadvantage of complicating installation work. This invention was made in view of the above circumstances,
The purpose of this is to create an air conditioning system that can easily perform air purging even without a power source by incorporating a check valve into the solenoid valve and pushing the check valve in the opening direction. It's something you're trying to gain. In other words, the present invention connects an outdoor unit equipped with a compressor and an outdoor heat exchanger, and a plurality of indoor units equipped with indoor heat exchangers, using a gas side operating valve and a liquid side operating valve provided on the outdoor unit side. This is an air-conditioning/heating system that is connected via a gas refrigerant pipe and a liquid refrigerant pipe, and is provided with a solenoid valve that controls the flow of refrigerant to the indoor unit in correspondence with the refrigerant pipe, and that connects the outdoor unit and the indoor unit during installation. Temporarily connect the air conditioner, open either the gas side operation valve or the liquid side operation valve to purge the indoor unit with air, then connect the piping and fully open both operation valves. This air-conditioning device is characterized in that at least one of the electromagnetic valve corresponding to the liquid refrigerant pipe and the electromagnetic valve corresponding to the liquid refrigerant pipe incorporates a check valve and an elastic body that presses the check valve in the opening direction. The present invention will be explained below based on illustrative embodiments. The heating and cooling device according to the present invention is as shown in FIG. In this heating and cooling system, the combinations and connections of the outdoor unit 1, indoor unit 2, etc. and their connections are the same as those shown in FIG. 1, and the explanation thereof will be omitted. The air conditioning system according to the present invention differs from the conventional one shown in FIG. 1 in that the two-way solenoid valve 10 corresponding to the gas refrigerant pipe 3 is replaced with a pilot type solenoid valve 15 with a check valve. This electromagnetic valve 15 will be explained below based on FIG. 3. The electromagnetic valve 15 includes a valve body 16 and an electromagnetic part housing 17 fixed to the upper part of the valve body 16. The valve body 1
6 forms a main valve chamber 18 inside, and this main valve chamber 18
communicates with an outlet port 21 through a communication passage 19 at its side bottom and a valve seat 20 at its center. A main valve 22 is loosely fitted into the main valve chamber 18 with a small gap between the main valve chamber 18 and the wall surface of the main valve chamber 18, and the main valve 22 is pressed upward by a spring 23. A soft plastic disk 24 provided in the center corresponds to the valve seat 20 communicating with the outlet port 21, and a pilot port 25 is formed in the center of the disk 24. Furthermore, inside the valve body 16, a main valve chamber 1 is provided.
A check valve chamber 26 is formed which communicates with the valve 8 through a communication passage 19. A valve seat 36 is provided between the check valve chamber 26 and the outlet port 21, and a check valve 27 having a groove 27a therein, as shown in FIG. 4, is brought into contact with and separated from the valve seat 36. Check valve chamber 26 then communicates with inlet port 28 . Further, this check valve 27 is pressed to the right in the figure by a spring 29 which is an elastic body. Further, a head 30 and a cylindrical guide 31 are attached to the housing 17, and a plunger 33 operated by an electromagnetic coil 32 is disposed within the guide 31.
The spring 23 is inserted between the plunger 33 and the head 30 so that the conical portion 34 at the tip of the plunger 33 is pressed against the pilot port 25.
A pressing spring 35 stronger than that is installed in a compressed manner. The inlet port 28 of the solenoid valve 15 is connected to the M side of the piping shown in FIG. 2, and the outlet port 21 is connected to the N side. The solenoid valve 15 configured in this way is used during cooling.
It acts as shown in Table 1 below during heating and air purge.

[Table] However, in terms of pressure levels, H indicates high pressure, L indicates low pressure, and M indicates balance pressure. In the force relationship between the front and back of the check valve, ΔP is the pressure due to the differential pressure between M and N, and F
indicates the pressure by the check valve built-in spring 29.
The spring constant of the spring 29 is determined to satisfy this relationship. During cooling operation, the refrigerant flows from N to M as shown by the solid arrow, and the pressing force due to the differential pressure and the pressing force due to the built-in spring are in the same direction, so this solenoid valve 15 is similar to the normal solenoid valve 10. It has the effect of In heating operation, the refrigerant flows from M to N as shown by the dashed arrow. In this case, the pressing force due to the differential pressure is selected so as to overcome the pressing force due to the spring 29, so this solenoid valve 15 has the same effect as the normal solenoid valve 10. Further, since the check valve 27 is opened by the action of the spring 29 when the differential pressure becomes small to a certain extent, the time required for stopping the operation can be shortened. At the time of air purge, after temporarily connecting the outdoor unit 1 and the indoor unit 2, as shown in FIG. 2, the operation valve 14 on the gas refrigerant pipe 3 side is opened. In this case, since the differential pressure between M and N is small, the spring 29 opens the check valve 27 and opens the refrigerant passage.
For this reason, the refrigerant in the outdoor unit 1 is released into the gas refrigerant pipes 3, passes through the indoor units 2, the liquid refrigerant pipes 4, and is purged with air at the operation valve 14 on the liquid refrigerant pipe 4 side. Complete piping connection work. After this, the operating valve 14 is fully opened to prepare for operation. Next, the flow of refrigerant within the solenoid valve 15 will be explained in detail with reference to FIG. When the fluid flows in the positive direction, that is, in the direction of arrow A, and the differential pressure between the inlet port 28 and the outlet port 21 overcomes the pressure of the spring 29, that is, during heating, the electromagnetic coil 32 is energized in the same way as a normal electromagnetic valve. Alternatively, the flow of fluid can be controlled by de-energizing. First, when the coil 32 is de-energized, the inlet port 2
The fluid entering from 8 (dashed arrow) flows into check valve chamber 2.
6, passes through the groove 27a in the same wall of the check valve 27, passes through the communication passage 19, and reaches the main valve chamber 18, but cannot flow because the main valve 22 is closed.
Further, since the check valve 27 receives fluid pressure from its back and comes into pressure contact with the valve seat 36, the fluid is not allowed to flow anywhere. When energized, the plunger 33 pushes the pressure spring 35 and opens the pilot port 25. At this time, the fluid that has entered the interior of the main valve chamber 18 flows through the interior of the valve seat 20 to the outlet port 21 . As a result, plunger 33
The pressure in the main valve chamber 18a on the side is the same low pressure as the outlet port 21, but since the fluid pressure in the communication passage 19 is higher than this, the main valve 22 is moved by the spring 2.
3, and rises due to the fluid pressure difference acting on the upper and lower end surfaces, and is separated from the valve seat 20. As a result, fluid entering from the inlet port 28 flows out from the check valve chamber 26 to the outlet port 21 through the communication passage 19, the lower main valve chamber 18b, and the inside of the valve seat 20. When the coil 32 is de-energized, the plunger 33
descends and closes the pilot port 25. Then, the pressure in the outlet port 21 becomes lower than that in both valve chambers 26 and 18b, so this pressure difference causes the main valve 22 to
descends by suppressing the force of the spring 23, and the valve seat 2
0 and close it. Inlet port 2 when fluid flows in the direction of arrow A.
When the differential pressure between 8 and the outlet port 21 overcomes the pressing force of the spring 29, specifically, it depends on the appropriate selection of the spring force, but this cannot occur during normal operation, such as during air purge when the refrigerant flow rate is low. In this case, there is communication between the inlet port 28 and the outlet port 21, and the refrigerant can pass through the solenoid valve 15 regardless of whether the electromagnetic coil 32 is energized or not. That is, in a state where no refrigerant flows, the pressure in the inlet port 28 and the outlet port 21 is equal, the check valve 27 is pressed to the right in the figure by the spring 29, and the valve seat 36 is opened. ing. At this time, when air purge is started, the refrigerant flows through the groove 27a on the same wall of the check valve chamber 26, causing a pressure loss therebetween, which causes a pressure difference between the inlet and outlet ports. In the air purge, the pressure drop is small because the flow rate passing through is small, and the force of the check valve 27 to move leftward due to the pressure difference is overcome by the rightward pressure of the spring 29, and the valve seat 36 is kept open. The condition remains and air purge is possible. When fluid flows in the opposite direction (solid arrow) from the outlet port 21 when the electromagnetic coil 32 is de-energized, that is, during cooling, the fluid cannot pass through the valve seat 20 because the main valve 22 closes the passage. The stop valve 27 is pushed to the right in the figure by a spring 29. Therefore, the passage of the valve seat 36 is open, and the inlet port 2 passes through the check valve chamber 26.
Flows to 8. In this case, the pressure loss of the check valve 27 is smaller than the pressure loss of the fluid in the main valve 22 when it passes through, so the flow rate of the fluid is large. As mentioned above, in this solenoid valve 15, fluid from the direction of arrow A does not flow unless the electromagnetic coil 32 is energized, but fluid from the opposite direction flows even when the electromagnetic coil 32 is not energized. It has the advantage that the number is greater than that in the positive direction. Therefore, when using the solenoid valve of the present invention,
Since there is no need to install a check valve during piping,
There are practical benefits in that piping materials, man-hours and space are reduced. In the above embodiment, a pilot type solenoid valve with a check valve is attached to the gas refrigerant pipe (low-pressure gas refrigerant pipe side during cooling), but the present invention is not limited to this. Alternatively, it may be provided in both the gas refrigerant pipe and the liquid refrigerant pipe. Further, in the above embodiment, a structure is shown in which the check valve 27 is opened in the opening direction using the compressive force of the spring 29, but the present invention is not limited to this, and the check valve 27 is opened using the tensile force from the opposite direction. It is also possible to have a structure in which 27 is in the open direction. Moreover, it is not limited to a spring, and may be other elastic body. The point is that it should be open when the refrigerant flow rate is low, such as during air purge, and closed when the differential pressure is large, such as during operation. As explained above, according to the present invention, air purge can be performed without energizing the solenoid valve, and the operation of the solenoid valve is not hindered in any way during operation, which eliminates the complexity of installation work. It has a remarkable effect.

[Brief explanation of the drawing]

Figure 1 is a refrigerant circuit diagram of a conventional heating and cooling system;
The figure is a refrigerant circuit diagram of an air conditioning system showing an embodiment of the present invention, Figure 3 is a sectional view of a pilot type solenoid valve with a check valve used in the air conditioning system, and Figure 4 is shown along the - line in Figure 3. FIG. 1...Outdoor unit, 2...Indoor unit, 3
... Gas refrigerant pipe, 4 ... Liquid refrigerant pipe, 5 ... Compressor, 6 ... Four-way valve for switching between air conditioning and heating, 7 ... Outdoor heat exchanger, 8 ... Check valve, 9 ... Expansion valve for heating , 10
... Two-way solenoid valve, 11 ... Indoor heat exchanger, 12
...Air conditioning expansion valve, 13...Check valve, 14...Operation valve, 15...Pilot type solenoid valve with check valve, 1
6... Valve body, 17... Solenoid housing, 18... Main valve chamber, 19... Communication passage, 20...
Valve seat, 21...Outlet port, 22...Main valve, 23...Spring, 24...Disk, 2
5... Pilot port, 26... Check valve chamber, 2
7... Check valve, 27a... Groove, 28... Inlet port, 29... Spring (elastic body), 30... Head, 31... Cylindrical guide, 32... Electromagnetic coil, 33... Plunger, 34... Conical part, 35
...Press spring, 36...Valve seat.

Claims (1)

[Scope of utility model registration request] An outdoor unit equipped with a compressor and an outdoor heat exchanger and a plurality of indoor units equipped with indoor heat exchangers are connected to each other by connecting a gas side operating valve, a liquid side operating valve, a gas refrigerant pipe, and a gas side operating valve provided on the outdoor unit side. An air conditioning/heating system that is connected via a liquid refrigerant pipe and is provided with a solenoid valve that controls the flow of refrigerant to the indoor unit corresponding to the refrigerant pipe, and temporarily connects the outdoor unit and the indoor unit during installation. After air purging of the indoor unit by opening one of the gas side operation valve or the liquid side operation valve, connect the piping and open both operation valves. 1. A heating and cooling device characterized in that at least one of the electromagnetic valves corresponding to the refrigerant pipe includes a check valve and an elastic body that presses the check valve in an opening direction.