JPH0743176B2 - Heat pump device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat pump device using a non-azeotropic mixed refrigerant.

Conventional technology Conventionally, in a heat pump device using a non-azeotropic mixed refrigerant,
It has been proposed to use a refrigerant rectification column to make the refrigerant composition of the main circuit of the refrigeration cycle variable so as to be excellent in load handling. Here, a part of the refrigerant in the main circuit is heated by a heater to boil it, and by the rectification action in the refrigerant rectification column, the low boiling point refrigerant is stored in the reservoir and the main circuit becomes the high boiling point refrigerant. The heat pump device has a capacity corresponding to the load by making the main circuit rich in the high boiling point refrigerant by enriching it or by returning the refrigerant in the reservoir to the main circuit. FIG. 3 shows our prior application as a conventional example of a heat pump device using a refrigerant rectification column.

In the figure, 1 is a compressor, 2 is a condenser, 3 is a main expansion device, and 4 is an evaporator, and these are connected by piping to form a main circuit of a refrigeration cycle. On the discharge side of the compressor 1, a discharge gas bypass circuit 6 that enters the heater 5 of the sub circuit is provided via a solenoid valve 7. An AC power supply 8 is supplied via a frequency converter 9 to drive the compressor 1.

The liquid refrigerant discharged from the condenser 2 is supplied by the first sub expansion device 10 to
The pressure is reduced to below the saturated liquid line, and is connected to the lower part of the refrigerant rectification column 11 through the heater 5. A packing material for the refrigerant rectification tower 11
12 filled. At the top of the refrigerant rectification tower 11 is a cooler 13
And a reservoir 14 are connected by a pipe 15, and a pipe 16 for returning from the reservoir 14 to the top of the tower is further connected. A pipe 18 from the lower part of the reservoir 14 via a solenoid valve 17 merges with a pipe 19 from the lower part of the refrigerant rectification column 11, and then is connected to the evaporator 4 through a second auxiliary expansion device 20. As a cooling source of the cooler 13, suction gas of the compressor 1 or the like is used (not shown).

In these circuits, a non-azeotropic mixed refrigerant is enclosed in an arbitrary composition.

Next, the operation of the heat pump device will be described.

When circulating the main refrigeration cycle with the enclosed refrigerant composition, the solenoid valve 7 is closed and the solenoid valve 17 is opened so that the gas component rising in the refrigerant rectification column 11 passes through the reservoir 14 as it is. And flows into the evaporator 4 from the second sub-expansion device 20, the rectification action does not work in the refrigerant rectification column 11, and the refrigerant is circulated with the enclosed composition as it is.

Next, the case of circulating a composition having a higher boiling point refrigerant than the enclosed composition will be described. By opening the solenoid valve 7 and closing the solenoid valve 17, the liquid refrigerant branched from the condenser 2 is set to the first
It is decompressed to below the saturated liquid line by the sub-throttler 10, and some gas components are generated to enter the heater 5. The heater 5 generates a gas component that further promotes the separation action, and enters the refrigerant rectification column 11 to rise. On the other hand, the rising gas is condensed and liquefied in the cooler 13, enters the reservoir 14, and is returned to the top of the tower through the pipe 16. The gas rising in the refrigerant rectification column 11 and the liquid descending are subjected to heat and mass exchange on the surface of the packing material 12 for gas-liquid contact, the lower boiling point refrigerant is concentrated in the reservoir 14, and the higher boiling point refrigerant is The refrigerant is returned from the lower part of the refrigerant rectification column 11 to the main cycle through the pipe 19, and as a result, the main refrigeration cycle side is concentrated to a high boiling point refrigerant.

Generally, when the main circuit is rich in low-boiling components, the capacity is increased, and when high-boiling components are rich, the capacity is decreased. In this conventional example, when the load increases, the solenoid valve 17 is opened and the solenoid valve 7 is closed, and when the load decreases, the solenoid valve 17 is closed and the solenoid valve 7 is opened conversely to change the refrigerant composition as described above. The operation is variable so that the capacity corresponding to the load is generated.

It is also possible to change the number of revolutions of the compressor 1 by the frequency converter 9 to change the refrigerant circulation amount in the main circuit to control the capacity, and in combination with the effect of the refrigerant composition change, a very wide capacity range. That is, it was able to operate in the load range.

Problems to be Solved by the Invention However, such a conventional device has the following drawbacks. That is, when the load is very small, the number of revolutions of the compressor 1 is reduced to reduce the refrigerant circulation amount, and the main circuit is operated by the composition of the high boiling point components by operating the solenoid valves 7 and 17, but the number of revolutions is high. If the value is too low, there is a lower limit because the motor torque decreases and the torque fluctuations become large, resulting in excessive current and damage to the motor. In addition, there is a limit to the composition of the refrigerant having a high boiling point, and the engine is often operated with a capacity larger than the required load. For this reason, the compressor's on / off operation was sometimes repeated, so the capacity / power value (hereinafter EE
R) had problems such as being low. Therefore, the present invention improves on the above-mentioned conventional drawbacks, and the compressor does not have to be turned on and off even under a very small load. It provides a high EER heat pump device that can handle high loads.

Means for Solving the Problems The technical means of the present invention for solving the above problems is, as a heating source of a heater of a refrigerant rectification column, a refrigerant gas that is being sucked into a compressor and is being compressed. It is used.

Action The action of this technical means is as follows.

That is, in the process of compressing the suction gas that has flowed into the compressor, a part of the gas is taken out and is allowed to flow into the heater as a heating source for the refrigerant rectification column to heat the refrigerant that has flowed into the sub-circuit. Performs rectification to change the refrigerant composition. Further, since this gas does not pass through the condenser or evaporator and is returned to the suction side of the compressor as it is, the amount of refrigerant circulating through the main circuit can be reduced and the capacity can be reduced. Therefore, the capacity can be widely changed by changing both the refrigerant composition and the refrigerant circulation amount.

Embodiment An embodiment of the present invention will be described with reference to FIG. First
In the figure, each of the components numbered 21 to 40 has the same name and the same function as the numbers 1 to 20 in FIG. The discharge gas bypass circuit is conventionally branched from the compressor 1, then branched to the heater 5, and after radiating heat, it is returned to the main circuit again. By introducing the discharge gas in the middle of compression in the cylinder of 21 into the discharge gas bypass circuit 26 toward the heater 25, the return gas of the return is returned to the suction side of the compressor 21 and merged with the main circuit. is there. The inside of the compressor 21 is roughly constructed as shown in FIG.

FIG. 3 is a schematic diagram of a rolling piston type compressor often used in an air conditioner or the like, in which the refrigerant flows into the cylinder 42 through the suction gas pipe 41, and the rotating piston 43 causes the gas in the hatched portion to flow. Although the compressed gas is shown, when the solenoid valve 27 is open, the compressed gas is discharged until the piston 43 closes the bypass hole 44.
Flows through the heater 25 and returns to the suction side as described above. As soon as the piston 43 passes the bypass hole 44, compression starts,
When it reaches a predetermined pressure, it flows out to the main circuit through the discharge circuit 45. When the solenoid valve 27 is closed, the normal compression process is performed as when the bypass hole 44 is not provided. Therefore, by opening the solenoid valve 27, a part of the sucked gas does not flow to the main circuit side, and the sucked gas pipe 41 → the cylinder 42 → the bypass hole is always provided.
44 → Discharge gas bypass circuit 26 → Solenoid valve 27 → Heater 25 → Suction gas pipe 41 is circulated, so that the circulation amount to the main circuit is reduced and the capacity can be lowered.

Considering together with the variable capacity of the refrigerant rectification column 31, when the load is large, by closing the solenoid valve 27 and opening 37, the bypass hole 44 of the compressor 21 is closed and the circulation amount becomes large, Moreover, since the low boiling point refrigerant that has been stored flows into the main circuit, the capacity becomes large. On the contrary, when the load is small, by opening the solenoid valve 27 and closing 37, the bypass hole 44 of the compressor 21 is opened and the circulation amount is reduced. Moreover, the bypass hole
Since the discharge gas from 44 flows into the heater 25, the refrigerant from the first auxiliary expansion device 30 is heated, and the low boiling point refrigerant is stored in the reservoir 34 by the above-described operation of the refrigerant rectification column 31. As a result, a large amount of refrigerant rich in high-boiling point flows in the main circuit.

Therefore, since the refrigerant rich in high-boiling components reduces the circulation amount and flows through the main circuit, the capacity can be considerably reduced. Moreover, by passing the bypass hole 44,
Electricity is reduced correspondingly to the amount of circulation to the main circuit, and EER
Does not decrease, so it is not necessary to turn the compressor 21 on and off even when the load is very small as in the conventional case, and it is possible to operate with EER kept high. In addition, by operating the compressor with a frequency variable device, it is possible to further broaden the capacity and expand the range of load compatibility.

Effects of the Invention As described above, the present invention uses a non-azeotropic mixed refrigerant, and uses a part of the refrigerant gas in the middle of compression in the compressor as a heating source for the refrigerant rectification column, so that a wide load can be achieved without lowering the EER. Can generate the ability corresponding to. In particular, when the load is small, the compressor can be continuously operated without being turned on and off as in the conventional case, so that the EER can be improved more than ever.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of the heat pump device of the present invention, FIG. 2 is a schematic diagram showing the inside of the compressor in FIG. 1, and FIG. 3 is a refrigerant circuit diagram of a conventional heat pump device. Is. 1,21 …… Compressor, 5,25 …… Heater, 6,26 …… Discharge gas bypass circuit, 7,17,27,37 …… Solenoid valve, 11,31 …… Refrigerant rectification column, 14, 34 …… reservoir, 44 …… bypass hole.

Claims (1)

[Claims] 1. A non-azeotropic mixed refrigerant is used as a heat refrigerant, and a compressor, a condenser, a main expansion device, an evaporator, etc. are annularly connected to form a main circuit, and a lower part is provided with a heater and a first auxiliary expansion device. A refrigerant rectification column, which is connected to the condenser outlet via the second sub-throttler, is connected to the condenser outlet via the second auxiliary expansion device, and the upper part of the rectification separator is connected to the cooler and the reservoir in order. Then, a circuit for returning to the upper part is provided again, the lower part of the reservoir is connected to the inlet of the second expansion device via an opening / closing valve, and the heater and the inside of the cylinder of the compressor are connected via an opening / closing valve. Direct connection, the refrigerant gas in the middle of compression of the compressor is introduced to indirectly exchange heat with the refrigerant at the outlet of the first auxiliary expansion device, and is returned to the suction side of the compressor again. Heat pump device.