JPH03281994A - Reciprocating type compressor for freezing device - Google Patents

Abstract

PURPOSE:To increase the volume efficiency and the compression efficiency of a compressor by providing an injection circuit to inject a part of a liquid coolant into a compression chamber from the upper side, and providing the injection circuit with a valve opened and closed by the pressure difference between the pressure in the compression chamber and the pressure in a suction chamber. CONSTITUTION:An injection circuit of a liquid coolant is provided from a condensor (not shown in the figure) to the upper side of a compression chamber 8, and a valve 21 is placed at the end of the injection circuit 20 positioned at the upper side of the compression chamber 8. This valve 21 furnishes a cylindrical case 22 and a columnar valve body 23 fitted sealing-slidable inside the cylindrical case 22, and it is composed by providing a flowing-in port 22a of the liquid coolant connected at the side of the case 22, a flowing-out port 22b of the liquid coolant connected at the bottom, and a pressure leading port 22c connected to the suction chamber 7 through a pressure leading pipe 24, respectively. And the valve body 23 of the valve 21 is opened and closed depending on the pressure difference between the pressure in the compression chamber 8 acting to the lower surface of the valve body 23, and the pressure in the suction chamber 7 acting to the lower surface of the valve body 23.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reciprocating compressor for refrigeration equipment such as air conditioners, water coolers, and refrigerators.

(Prior Art) An example of a conventional reciprocating compressor for an air conditioner is shown in FIG.

In FIG. 5, 1 is a cylinder, 2 is a piston, 3 is a connecting rod, 4 is a crankshaft, 5 is a head cover, 6 is a valve plate, 14 is an intake valve, 15 is a discharge valve, and 7
8 is a suction chamber, 8 is a compression chamber, 9 is a discharge chamber, IO is a discharge pipe, and 13 is a retainer of the discharge valve 15.

A refrigerant liquid introduction pipe 11 for introducing a part of the liquid refrigerant liquefied by a condenser (not shown) is bored in the cylinder 1 so as to be located near the bottom dead center of the piston 2. A valve 12 is interposed.

Therefore, during normal operation, the solenoid valve 12 is closed,
The piston 2 is driven by the rotation of the crankshaft 4 via the connecting rod 3 and moves up and down within the cylinder l. Then, gas is sucked into the compression chamber 8 from the suction chamber 7 through the suction valve 14, and the gas compressed in the compression chamber 8 passes through the discharge valve 15 and the discharge chamber 9 and is discharged from the discharge pipe IO.

On the other hand, during heating operation, the compressed gas becomes extremely high in temperature, so that the cylinder 11, the hend cover 5, the valve plate 6, etc. also become high in temperature, resulting in a decrease in volumetric efficiency and compression efficiency. Therefore,
In such a case, the solenoid valve 12 is opened. Then, a part of the liquid refrigerant liquefied in the condenser flows into the refrigerant liquid introduction pipe 11,
When the piston 2 descends via the solenoid valve 12, the compression chamber 8
The compressed gas is cooled by the evaporation of this refrigerant liquid.

(Problems to be Solved by the Invention) In the conventional compressor described above, since the outlet of the refrigerant liquid introduction pipe 11 is opened and closed by the piston 2, liquid refrigerant flows into the compression chamber 8 even at the beginning of the suction stroke of the piston 2. Therefore, there is a disadvantage that the suction of the gas into the compression chamber 8 is prevented and the volumetric efficiency is reduced.

To deal with this, if the refrigerant liquid introduction pipe 11 is opened close to the bottom dead center of the piston 2, the opening time of the refrigerant liquid introduction pipe 11 during the compression stroke will be shortened, and the injection amount of liquid refrigerant will be reduced. , there is a problem that the compressed gas is not sufficiently cooled.

(i! [Means for solving the problem)] In view of the above circumstances, the present invention aims to inject a sufficient amount of liquid refrigerant during the compression stroke of the piston, and stop the injection of liquid refrigerant during the suction stroke. The gist of the system is that it includes an injection circuit that injects a portion of the liquid refrigerant liquefied in the condenser into the compression chamber from above, and an injection circuit that is connected to the injection circuit to control the pressure inside the compression chamber and the suction chamber. A reciprocating compressor for a refrigeration system is characterized by comprising a pulp that opens and closes depending on the pressure difference between the pulp and the pulp.

(Function) Since the present invention has the above configuration, during the compression stroke of the piston, the pressure in the compression chamber becomes higher than the pressure in the suction chamber and the pulp opens, so that the liquid refrigerant liquefied in the condenser is is injected into the compression chamber from above through the injection circuit. However, during the suction stroke of the piston, the pressure in the compression chamber becomes lower than the pressure in the suction chamber and the valve closes, so that no liquid refrigerant is injected.

(Embodiment) An embodiment of the present invention is shown in FIGS.
The figure is a partial vertical sectional view of a reciprocating compressor, Figures 2 and 3.
The figures show the operating states of the pulp.

In FIG. 1, reference numeral 20 denotes a liquid refrigerant injection circuit, which is disposed from a condenser (not shown) to the upper part of the compression chamber 8, and is located at the end of the injection circuit 20, that is, at the upper part of the compression chamber 8. Pulp 21 is interposed.

As shown in FIGS. 2 and 3, this valve 21 consists of a cylindrical case 22 and a cylindrical valve body 23 fitted in a sealed and slidable manner. There is a liquid refrigerant inlet 22a1 and a liquid refrigerant outlet 22b1 at the bottom.
A pressure guiding port 22c is provided in the upper part. The inlet 22a is connected to the injection circuit 20, the outlet 22b opens into the compression chamber B, and the pressure guiding port 22c
communicates with the suction chamber 7 via a pressure guiding pipe 24.

In addition, the valve body 23 has a passage 2 penetrating from its side to the bottom.
3a is formed.

The rest of the structure is the same as the conventional one shown in FIG. 5, and corresponding members are given the same reference numerals.

Thus, the valve element 23 of the valve 21 slides up and down within the case 22 based on the pressure difference between the pressure in the compression chamber B acting on its lower surface and the pressure in the suction chamber 7 acting on its upper surface.
When the valve body 23 rises as shown in FIG. 2 and comes into contact with the upper surface of the first valve 22, the inlet 22a and the passage 238 communicate with each other, and the injection circuit 20 is opened. On the other hand, as the valve body 23 descends as shown in FIG.
and the passage 23a are cut off, and the injection circuit 20 is closed.

Note that, as shown in FIG. 4, the valve 21 may be provided outside the reciprocating compressor, and the refrigerant outflow pipe 25 may be extended to the upper part of the compression chamber 8. Further, the injection circuit 20 may be provided with a check valve 26 for preventing high-pressure refrigerant gas from flowing backward from the compression chamber 8 .

The solenoid valve 12 is opened during operation at a high compression ratio, such as during heating operation. During the compression stroke of the piston 2, the pressure in the compression chamber 8 becomes higher than the pressure in the suction chamber 7, so as shown in FIG. 2, the valve body 23 rises and the injection circuit 20 opens. Then, the negative part of the liquid refrigerant liquefied in the condenser is transferred to the injection circuit 20,
The liquid refrigerant is injected into the upper part of the compression chamber 8 through the electromagnetic valve 12 and the valve 21, and the compressed gas is cooled by the evaporation of this liquid refrigerant.
On the other hand, during the suction stroke of the piston 2, the pressure in the compression chamber 8 becomes lower than the pressure in the suction chamber 7, so the valve body 23 moves downward as shown in FIG.

Then, the injection circuit 20 is closed and the injection of liquid refrigerant is stopped.

Thus, a sufficient amount of liquid refrigerant is injected during the compression stroke to sufficiently cool the compressed gas.

Also, since the injection of liquid refrigerant is stopped during the suction stroke,
Only the suction gas is sucked into the compression chamber 8, improving the volumetric efficiency and compression efficiency of the reciprocating compressor.

(Effect of the invention) In the present invention, during the compression stroke of the piston, the pressure in the compression chamber becomes higher than the pressure in the suction chamber and the pulp opens, so a part of the liquid refrigerant liquefied in the condenser passes through the injection circuit and is compressed. It is sprayed into the room from the top. However, during the suction stroke of the piston, the pressure inside the compression chamber becomes lower than the pressure inside the suction chamber and the pulp closes, so that no liquid refrigerant is injected.

As a result, a sufficient amount of liquid refrigerant is injected into the compression chamber during the compression stroke of the piston, so only the compressed gas is sucked into the compression chamber, which increases the volumetric efficiency and compression efficiency of the reciprocating compressor. increases.

[Brief explanation of the drawing]

Figure 1 is a partial vertical sectional view of the reciprocating compressor, Figure 2 is an enlarged sectional view showing the operating state of the valve during the compression stroke, and Figure 3 shows the operating state of the valve during the suction stroke. This is an enlarged cross-sectional view. FIG. 4 is a partial vertical sectional view of a reciprocating compressor showing another embodiment of the present invention. FIG. 5 is a partial vertical sectional view showing a conventional reciprocating compressor. Suction chamber - 7, Cylinder chamber -8, Injection Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] An injection circuit that injects a part of liquid refrigerant liquefied in a condenser into a compression chamber from above, and a valve that is installed in this injection circuit and opens and closes depending on the pressure difference between the pressure inside the compression chamber and the pressure inside the suction chamber. A reciprocating compressor for a refrigeration system, comprising: