JPS5926864B2 - Heat pump refrigeration cycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat pump type refrigeration cycle with an improved refrigerant circulation structure.

A refrigeration cycle is constructed by sequentially connecting a compressor, condenser, pressure reducer, evaporator, etc. via refrigerant pipes, and by adjusting the capacity of the compressor, it is possible to adjust the refrigeration capacity, load adjustment, power consumption adjustment, etc. It is now possible to do this.

One method for adjusting the capacity of the compressor is to release refrigerant gas during the compression process of the compressor to the suction pipe to measure the decrease in capacity.

Particularly in so-called rotary compressors, in which a roller rotates eccentrically within a cylinder while sucking in and compressing refrigerant, it is common to open and close a release hole formed in the cylinder on the side surface of a cylindrical roller.

On the other hand, in order to cool the compressor (to prevent seizure due to overheating), a method has been considered in which liquid refrigerant is fed into the cylinder from the suction pipe or the release hole and the latent heat of vaporization is utilized.

However, the conventional system has a compressor capacity adjustment mechanism and a cooling mechanism as independent mechanisms, which has the disadvantage of complicating the structure and increasing costs.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a heat pump type refrigeration cycle in which compressor capacity adjustment and cooling can be performed with a simple configuration.

An embodiment of the present invention will be described below with reference to FIGS. 1' to 3.

In the figure, 1 is a rotary complete compressor, and this compressor 1 includes a four-way valve 2, an outdoor heat exchanger 3, a capillary tube 4,
4 and the indoor heat exchanger 5 are connected to form a heat pump type refrigeration cycle.

Further, a liquid injection circuit 6 is provided which connects the cylinder of the compressor 1 and the capillary tubes 4, 4, and a bypass circuit 7 which connects the middle part of this liquid injection circuit 6 with the suction side of the compressor 1 is provided. A check valve 8 is provided in the middle of this bypass circuit 7.

On the other hand, the compressor 1 is constructed as shown in FIGS. 2 and 3.

That is, reference numeral 9 denotes an electric motor section consisting of a rotor 10 and a stator 11, and a compression mechanism section 12 is provided in the lower part of this electric motor section 9.

The compression mechanism section 12 is connected to the cylinder 1 as shown in FIG.
3 and a roller 14 which is provided inside the cylinder 13 and rotates eccentrically.The cylinder 13 is provided with a suction port 15 and a discharge port 16 on the inner peripheral side thereof.

Further, a blade 17 is provided between the suction port 15 and the discharge port 16 so as to be freely raised and submerged, and the inside of the cylinder is partitioned into a compression chamber 18 and a suction chamber 19 by the blade 17.

Furthermore, a release hole 20 is provided at the inner bottom of the cylinder 13.
is bored, and one end of the bypass circuit 7 is connected to this release hole 20.

When the compressor 1 is operated, during cooling operation, the discharged refrigerant gas is sent to the outdoor heat exchanger 3, where it is heat-radiated and condensed, and then sent to the indoor heat exchanger 5 via the capillary tube 4, where it is sent to the indoor heat exchanger 5. After being evaporated and vaporized, it is sucked into the compressor 1.

Thereafter, the refrigerant is similarly circulated and cooling operation is continued.

During this cooling operation, refrigerant gas in the cylinder of the compressor 1 is released to the suction side of the compressor 1 via the bypass circuit 7.

At the same time, a part of the liquefied refrigerant flowing out from the capillary tube 4 is flowed to the suction side of the compressor 1 via the liquid injection circuit 6 and the bypass circuit 7.

As a result, the capacity is significantly reduced during cooling, and liquid refrigerant is supplied to the suction side of the compressor 1, so that the compressor 1 can be reliably cooled.

Furthermore, during heating operation, the discharged refrigerant gas is sent via the four-way switching valve 2 to the indoor heat exchanger 5, which acts as a condenser, where it is heat-radiated and condensed, and then acts as an evaporator via capillary tubes 4, 4. It flows into the outdoor heat exchanger 3, where it is evaporated and vaporized, and then sucked into the compressor 1.

During this operation, a part of the liquefied refrigerant flowing out from the capillary tube 4 is sent into the cylinder via the liquid injection circuit 6 to cool the compressor 1.

In this way, by lowering the cycle capacity for cooling operation and fully utilizing the cycle capacity for heating operation, it is possible to ensure cooling of the compressor while matching the compressor 1 during air conditioning operation. In general, in a heat pump type refrigeration cycle, both indoor and outdoor temperatures are lower during heating operation, so the refrigerant pressure also decreases. However, the method described above allows for a simple refrigeration cycle structure (with one check valve 8).
It is possible to overcome this drawback by simply adding one (1).

As explained above, the present invention includes a liquid injection circuit that connects an outdoor heat exchanger and an indoor heat exchanger with a compression chamber of a compressor and supplies liquid refrigerant to the compression chamber during heating; A bypass circuit is provided which is branched out from the middle of the injection circuit and connects the compression chamber of the compressor during cooling to the suction pipe of the compressor and supplies refrigerant gas from the compression chamber and liquid refrigerant from the liquid injection circuit to the suction pipe. Therefore, it is possible to adjust the capacity of the compressor with a simple structure compared to the conventional one that has separate injection and release mechanisms, and it is possible to match the capacity of air conditioning and heating, and it is also possible to cool the compressor. This has the effect of being extremely economical.

Also, by connecting one end of the liquid injection to any point between the indoor heat exchanger and the outdoor heat exchanger,
It is also possible to adjust the amount of liquid injection.

Furthermore, according to the present invention, compared to the conventional release mechanism, the liquid refrigerant from the liquid injection circuit during cooling is returned to the suction pipe of the compressor via the bypass circuit, and only the returned amount is sent to the evaporator. This also has the effect of increasing the variable range of the compressor's capacity, since the amount of refrigerant used in the compressor decreases and the capacity of the compressor decreases.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a schematic configuration diagram showing a heat pump type refrigeration cycle, FIG. 2 is a vertical sectional view showing the internal mechanism of the compressor, FIG. 3 is a cross-sectional view showing the compression mechanism section. 1... Compressor, 2... Four-way valve, 3...
... Indoor heat exchanger, 4 ... Pressure reducing device evaporator, 5 ... Outdoor heat exchanger, 6 ... Liquid injection circuit, 7 ... ...Bypass circuit.

Claims (1)

[Claims] 1. In a heat pump type refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, a pressure reducing device, and an indoor heat exchanger are sequentially connected via refrigerant pipes, the outdoor heat exchanger and the outdoor heat exchanger a liquid injection circuit that connects the space between the compressor and the compression chamber of the compressor and supplies liquid refrigerant to the compression chamber during heating;
The liquid injection circuit is branched out from the middle of the liquid injection circuit, and communicates the compression chamber of the compressor with the suction pipe of the compressor during cooling, and supplies refrigerant gas from the compression chamber and liquid refrigerant from the liquid injection circuit to the suction pipe. A heat pump refrigeration cycle featuring a bypass circuit.