JPS6040783B2 - Air conditioner refrigeration circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration cycle for an air conditioner, and one of its objects is to enable multi-purpose refrigeration cycle control with one bypass pipe.

In the refrigeration cycle of an air conditioner, there is a configuration in which a bypass pipe is installed between high and low pressure pipes, and a solenoid valve is installed in this bypass pipe. It is possible to stop and circulate the refrigerant flow in one direction, but it is impossible to stop the cold soot flow in the opposite direction, or it is possible to stop and circulate the refrigerant flow in one direction, but it is not possible to stop the cold soot flow in the opposite direction. Since no flow was possible, the only way to do so was to stop the flow of cold soot in one direction in the bypass pipe.

That is, the conventional solenoid valve used in the bypass circuit of this type of refrigeration cycle was constructed as shown in FIG.

In FIG. 3, a solenoid valve 1 includes cold soot pipes a and b, a valve body 12 whose position is fixed, a plunger 13 pulled up by a Kameji coil 14, and a plunger 1.
It is composed of a cylindrical body 11 that houses a spring 15 etc. that pushes down the cylindrical body 3, and performs the following operations. Now electromagnetic coil 14
Assuming that is in a non-energized state, there is a slight gap between the cylinder 11 and the plunger 13, so the pressure Pa inside the cold soot pipe a and the spring 1 of the cylinder 11 and the plunger 13
The pressures Pc in the space created by the contact surface and the contact surface Pc are equal.

If the area of the surface where the plunger 13 contacts the spring 15 is Ap, the cross-sectional area of the hole 17 in the valve body 12 is Av, the pushing force of the spring 15 on the plunger 13 is Fs, and the weight of the plunger is Fp. , the push-up force F of the plunger 13 is F,=Fs+Fp+ApP
It becomes a. On the other hand, the force F2 that tries to push the plunger 13 upward becomes F2=AvPR. Generally, the relationship between the areas Ap and Av is Ap》Av, so at least when the pressure Fa>Pb, the forces F and F2 become F,>F2, so the plunger 13 is pushed downward with a strong force. Thus, the hole 16 of the valve body 12 is closed by the tip of the plunger 13, and the refrigerant pipe a and the cold soot pipe b are not allowed to flow. When the electromagnetic coil 14 is energized from this state, the plunger 13 is pulled up by the force FC due to the magnetic force of the coil 14. <F20Fc, the plunger 13 is pulled upward, and the hole 17 of the valve body 12 accommodates the refrigerant pipe a and the refrigerant pipe b.

On the other hand, when the coil 14 is de-energized and the pressure Pb in the soot pipe a becomes higher than the pressure Pa in the refrigerant pipe b to some extent, F2>
Since the state F occurs and the plunger 13 is pushed upward, the flow from the cold soot pipe a to the cold soot pipe b cannot be stopped even if the coil 14 is de-energized.

Therefore, the refrigerant flow in the bypass pipe, whose flow direction changes between cooling and heating operations, cannot be freely stopped and circulated, and for example, during cooling operation, the refrigerant flow in the bypass pipe connecting a high-pressure pipe to a low-pressure pipe cannot be cooled. If a solenoid valve is installed so that the soot flow can only be stopped and allowed to flow from the high-pressure pipe to the low-pressure pipe, the soot medium flow in the bypass pipe can only be stopped and allowed to flow during cooling operation, and heating There is a drawback in that it is impossible to stop the flow of refrigerant flowing in the opposite direction through the bypass pipe during operation, or it is impossible to flow the refrigerant through the bypass pipe at all.

In other words, during cooling operation, when there is an overload or low load condition, the overload or low load condition can be eliminated by flowing the fermentation medium through this bypass pipe in a timely manner, and during heating operation, the heat source It is possible to create a bypass circuit to remove frost from the side heat exchanger, or to balance high and low pressure when the compressor is stopped, but on the other hand, it is possible to create a bypass circuit to remove frost from the side heat exchanger, or to balance high and low pressure when the compressor is stopped. This has major drawbacks, such as a decrease in heating capacity due to the flow of soot, and an inability to perform overload control, low load control, or promote pressure balance when the compressor is stopped because cold soot does not flow through the solenoid valve. There is.

In addition, a capillary tube or the like is provided in this bypass pipe in order to ensure an appropriate bypass flow rate due to various controls, but there is a problem that various controls cannot be performed optimally with this fixed resistor. The present invention eliminates the drawbacks found in the conventional refrigeration cycles described above. Hereinafter, the present invention will be explained with reference to FIGS. 1 and 2 of the accompanying drawings showing one embodiment thereof.

In FIG. 1, the refrigeration circuit is constructed by sequentially connecting a compressor 1, a four-way valve 2, a heat exchanger 3 on the heat source side, a heat exchanger 4 on the user side, and a heat exchanger 5 on the user side. A first pipe line 6 that connects the heating device 4, a user-side heat exchanger 5, and a four-way valve 2
A bypass pipe 8 is connected to a second conduit 7 that connects the valve, and a bypass pipe 8 is provided in the bypass pipe 8 in series with the capillary tube 17 in both directions when the current is not energized, so that the valve can be closed even if the differential pressure across the valve is large. A reversible thermoelectric variable resistance valve 9 is provided that can change the flow rate in both directions when energized.

Next, a second section regarding the structure of the reversible thermoelectric variable resistance valve 9 will be explained.
This will be explained with reference to the diagram.

The reversible thermal crab type variable resistance valve 9 has a valve part 19 and a valve driving part 2.
Consists of 0. The valve part 19 consists of a valve body 21 and a valve body 22. The valve frame 21 is provided with a valve seat portion 22 and has inflow and outflow boats 24 and 25 through which fluid flows in and out.
Refrigerant pipes 26 and 27 are connected to the refrigerant pipes 26 and 27, respectively. The valve body 22 consists of two connected upper and lower members 28 and 29,
Passages 30 and 31 are formed in these members 28 and 29 to allow passage between the boat 24 side and the inside of the valve driving portion 20.
A check valve 32 is provided between the passages 30 and 31 to prevent the refrigerant from flowing from the passage 30 toward the pilgrimage route 31. Note that the valve body 22 is provided in a hole 33 formed in the valve frame 21 so as to be slidable up and down. On the other hand, the valve driving portion 20 forms a sealed space 36 with the upper casing 34, the lower casing 35, and the valve frame 21. this space 36
Two bimetals 37 and 38 are stored inside.
Both bimetals 37 and 38 have smooth surfaces 39 and 39 at both ends.
They are arranged in parallel via 40. And both bimetal 3
Holes 41 and 42 are bored in the center of the valve body 22, and a support pin 43 fixed to the center of the inner surface of the upper casing 34 is inserted from above into the hole 41 of the upper bimetal 37. By inserting the formed pin portion 44 into the hole 42 of the lower bimetal 38 from below, both bimetals 37
, 38 are supported within the space 36. Note that the valve body 22 is always urged upward by a spring 46 via a washer 45. 47 is an electric heater for forcibly heating the upper bimetal 37, and is wrapped around the upper bimetal 37.

Terminals 48 and 49 are connected to both ends of the electric heater 47 and are provided through the upper casing 34.

This upper bimetal 37 is forcibly heated by the electric heater 47 so that both ends thereof are directed upward (in the direction of arrow A in the figure).
It transforms so that it moves. Therefore, when the electric heater 47 is energized, the upper bimetal 37 is deformed, and the spring 46 pushes the valve body 22 upward, causing the valve seat 23 to
and the lower end of the valve body 22 is opened. That is, the valve is opened. The valve function in this case is adjusted by the amount of electricity supplied to the electric heater 47. That is, when a large amount of electric power is passed through the upper bimetal 37, the upper bimetal 37 is greatly deformed and curved, and the valve resistance becomes large. Conversely, when the electric power applied to the electric heater 47 is small, the amount of deformation of the upper bimetal 37 is small, and the degree of deformation of the valve is small. Note that the lower bimetal 38 is connected to the hole 33 and the valve body 22.
It is a bimetal for load condition compensation, and deforms under the influence of the cold soot that flows into the space 36 from the super-dynamic surface and the temperature of the surrounding air. Further, this reversible thermoelectric expansion valve 9 is a variable resistance valve of a forward and reverse flow type, and cold soot flows in from the boat 24 and passes through the crest formed between the valve body 22 and the valve seat 23. It goes without saying that the flow flows out from the boat 25, but conversely, the flow flows from the boat 25 and flows out from the boat 24 through the crest formed between the valve body 22 and the valve seat 23. It can also flow.
Note that when the pressure on the boat 25 side becomes high and the pressure on the boat 24 side becomes low, a part of the refrigerant flows into the space 36 from the sliding surface between the valve body 22 and the hole 23, but this inflow flows through passages 30, 31 and check valve 32 to boat 24 and does not accumulate in space 36. Conversely, when the pressure on the boat 24 side becomes higher than that on the boat 25 side, the check valve 32 closes and almost no refrigerant flows into the space 36. In the above configuration, the refrigerant discharged from the compressor 1 during cooling operation is transferred to the four-way valve 2, the heat source side heat exchanger 3, the first pipe line 6, the frizz device 4, the user side heat exchanger 5, and the second pipe line 7.
, the flow passes through the four-way valve 2 in sequence and returns to the compressor 1 again.

At this time, the reversible thermoelectric variable resistance valve 9 in the bypass pipe 8
As explained above, since the heater 47 is de-energized, the refrigerant tube 26 and the refrigerant tube 27 are not suitable for use. Therefore, no refrigerant flows through the bypass pipe 8. Here, because the pressure Pa in the first pipe line 6 has increased abnormally due to the warm green state of the heat source side heat exchanger 3 and the usage side heat exchanger 5, this Pa
In order to lower the temperature, a voltage is applied to the reversible thermoelectric variable resistance valve 9 in the bypass pipe 8 to achieve the optimum valve resistance. Therefore, the operation of the reversible thermoelectric variable resistance valve 9 is performed as described above, and the cold butterfly flows in the bypass pipe 8 from the first pipe line 6 side to the second pipe line 7 side, reducing the pressure Pa. Overload operation of the compressor 1 can be prevented. The same applies when the cooling operation is in a so-called low load state where the pressure Pb in the second pipe 7 drops abnormally and the liquid refrigerant returns to the compressor 1, or where frost forms on the heat exchanger 5 on the user side. A voltage is applied to the heater 47 of the reversible thermal haze type variable resistance valve 9 to achieve the optimum valve resistance, and soot flows from the first pipe line 6 to the second pipe line 7 to increase Pb and avoid a low load state. can do. Furthermore, when the compressor 1 is stopped during this cooling operation, the maximum voltage is applied to the heater 47 of the reversible thermoelectric variable resistance valve 9 to fully open the valve, and the first pipe line 6 in a high pressure state is connected to the second pipe in a low pressure state. Cold soot can flow into the pipe line 7, thereby reducing the pressure difference between the pressure Pa in the first pipe line 6 and the pressure Pb in the second pipe line 7 in a short time, and restarting the compressor 1. It can also make it easier to work.

On the other hand, during continuous heating, the refrigerant discharged from the compressor 1 is transferred to the four-way valve 2.
, the second pipe line 7, the user side heat exchanger 5, the heat exchanger 4, the first pipe line 6, the heat source side heat exchanger 3, the four-way valve 2, and then returning to the compressor 1 again. do.

At this time, the reversible thermoelectric variable resistance valve 9 in the bypass pipe 8
As explained above, since the heater 47 is de-energized, the refrigerant pipe 26 and the cold soot pipe 27 do not pass through each other, and no cold fluid flows through the bypass pipe 8. Here, as in the case of cooling earlier, when the pressure Pb in the second pipe line 7 abnormally increases due to the temperature and humidity conditions of the heat source side heat exchanger 3 and the user side heat exchanger 5, a so-called overload condition occurs. In order to lower the pressure Pb, the reversible thermoelectric variable resistance valve 9 in the bypass pipe 8 is opened. therefore,
The operation of the reversible thermoelectric variable resistance valve 9 is performed as described above, and the refrigerant flows through the bypass pipe 8 from the second pipe line 7 side to the first pipe line 6 side, reducing the pressure Pb and compressing it. Prevent overload operation of machine 1. Also, in this heating operation state, when the liquid refrigerant returns to the compressor 1 due to an abnormal drop in the pressure Pa in the first pipe line 6, a so-called low load state occurs.
Similarly, cold soot flows from the second pipe line 7 to the first pipe line 6 by applying a voltage to the heater 47 of the reversible thermal tortoise variable resistance valve 9 to achieve the optimum valve resistance, thereby increasing Pa and lowering the temperature. Load conditions can be avoided. Furthermore, when the compressor i is stopped during heating operation, the maximum voltage is applied to the heater 47 of the reversible thermoelectric variable resistance valve 9 to fully open the valve, and the second pipe line 7, which is in the double pressure state, is connected to the second pipe line 7, which is in the low pressure state. 1 pipe 6, the pressure Pb in the second pipe 7 and the pressure Pa in the first pipe 6
It is also possible to reduce the pressure difference in a short time and make it easier to restart the compressor 1. Furthermore, during heating operation, in order to remove frost on the heat source side heat exchanger 3, when temporarily switching to the cooling cycle, the optimum opening degree of the heater 47 of the reversible thermoelectric variable resistance valve 9 in the bypass pipe 8 is set. By applying a voltage of You can also do frosting. By the way, if the slave solenoid valve 10 shown in FIG. 3 is used instead of the reversible thermoelectric variable resistance valve 9, the operation will be the same as the previous one during cooling operation, but the second one will operate during heating operation. The pressure Pb on the pipe line 7 side is higher than the pressure P on the first pipe line 6 side.
a, the plunger 13 is pushed up, and therefore the cold soot pipe 27 and the cold refrigerant pipe 26 are constantly
This will cause the heating capacity to decrease.

Further, in such a configuration, the capillary tube 17 is provided in the bypass pipe 8 in series with the solenoid valve 10, and various controls cannot be performed optimally. As a result, it is not possible to use the conventional solenoid valve 10 in place of the reversible thermoelectric variable resistance valve 9, and if you are forced to use the solenoid valve 10, it is necessary to use two solenoid valves with the outlet pipes b facing each other. It is costly and prone to failure. As is clear from the above embodiments, the refrigeration circuit of the air conditioner according to the present invention is provided so that a single bypass pipe can serve as both the high pressure side and low pressure side during cooling operation and the high pressure side and low pressure side during heating operation. A reversible thermoelectric variable resistance valve is installed in this bypass pipe, which can open and close the valve even if there is a large pressure difference in both directions when the current is not applied, and which can vary the flow rate in both directions when the current is applied. A single reversible thermoelectric variable resistance valve can optimally control overload and low load (low temperature) during cooling operation, promote pressure balance when the compressor is stopped, and provide bypass control during defrosting operation. It has many advantages, such as control, making the circuit simple and inexpensive, and making maintenance extremely easy.

Brief description of the drawings: Figure 1 is a refrigeration circuit diagram of an air conditioner according to an embodiment of the present invention, Figure 2 is a sectional view of a reversible thermoelectric variable resistance valve constituting the refrigeration circuit, and Figure 3 is a sectional view of a reversible thermoelectric variable resistance valve that constitutes the refrigeration circuit. It is a sectional view of a solenoid valve provided in a bypass circuit in a conventional example.

1... Compressor, 2... Four-way valve, 3...
Heat source side heat exchanger, 4... Fingerprint device, 5...
Utilization side heat exchanger, 6... First pipe line, 7...
Second pipe line, 8... Bypass pipe, 9... Reversible thermoelectric variable resistance valve.

Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A refrigerant circulation circuit is formed by a compressor, a four-way valve, a heat source side heat exchanger, a heat exchanger, and a usage side heat exchanger, and in the first pipe line connecting the heat source side heat exchanger and the usage side heat exchanger. A bypass pipe connects a pipe section that becomes high pressure during cooling operation and low pressure during heating operation and a second pipe line connecting the user-side heat exchanger and the four-way valve, and a reversible thermoelectric generator is installed in this bypass pipe. A refrigeration circuit for an air conditioner equipped with a variable resistance valve.