JPH0626711A - Freezer - Google Patents

Abstract

PURPOSE:To prevent the amount of liquid injection from being made excessive or insufficient upon operation and prevent a liquid level in a condenser from being lowered in a freezer using a liquid injection type compressor. CONSTITUTION:A liquid injection flow rate is controlled with a liquid injection flow rate adjusting valve 7 provided in a refrigerant circuit by monitoring teeth groove pressure of a compressor through a pulsation absorption device 8. Accordingly, operation is ensured at a proper liquid injection flow rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to liquid injection flow rate control for a compressor using a liquid injection system.

[0002]

2. Description of the Related Art FIG. 3 is a refrigerant circuit diagram of a conventional device using a liquid injection type compressor.
Reference numeral 1 is an evaporator for evaporating a refrigerant, 2 is a compressor for sucking the gas evaporated in the evaporator 1 and compressing it to generate high-pressure heating vapor, 3 is a condenser for cooling and condensing the vapor, and 4 is a condensate thereof. Is an expansion valve for squeezing and expanding, and 5 is an electromagnetic valve for sending a part of the condensate from the condensate to the compressor, and 6 is a nozzle for limiting the flow rate of the liquid.

Next, the operation will be described. The high-pressure refrigerant liquid condensed and liquefied by the condenser 3 is injected into the tooth space of the compressor through the nozzle 6 by opening the electromagnetic valve 5 simultaneously with the operation of the compressor 2.

[0004]

Since the conventional liquid injection device is constructed as described above, there is no problem in the steady state, but during high differential pressure operation or bottom differential pressure operation, the liquid injection flow rate is excessive or insufficient. There were problems such as.

The present invention has been made to solve the above problems, and an object thereof is to obtain a flow rate control device capable of performing a proper amount of liquid injection into a compressor even if the pressure difference fluctuates. To aim.

[0006]

A refrigeration system according to the present invention comprises a flow control valve in the middle of a liquid injection pipe, and a pulsation absorbing device for monitoring the pressure of a tooth space of a compressor to be liquid injected. .

[0007]

The liquid injection flow rate control valve according to the present invention operates by monitoring the tooth groove pressure of the compressor for liquid injection through the pulsation absorbing device, so that an appropriate flow rate can always be obtained.

[0008]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 7 is a flow control valve arranged in place of the nozzle, and 8 is a pulsation absorbing device provided between the flow control valve 7 and the compressor 2. FIG. 2 is an enlarged cross-sectional view of the flow rate control unit, 9 is an outer casing of the valve, 10 is a valve body that determines the passage area of the refrigerant liquid flowing from the A direction (evaporator), and 11 is a direction in which the valve body is opened Adjustment spring to press
Reference numeral 12 is a piston that pushes in the direction of opening the valve body by the tooth groove pressure of the compressor, which is pressure-equalized from the B direction (compressor) through the pulsation absorbing device 8, and 13 is a cylinder in which this piston slides. 14 is a connecting rod for transmitting the force of the piston 12 and the adjusting spring 11 and the force of the high pressure applied to the valve body 10,
Reference numeral 15 is an adjusting screw for ensuring the minimum required injection amount of the liquid so that the valve body is not fully closed.

In the liquid injection flow rate control device constructed as described above, the adjusting screw 15 secures a passage through which the minimum flow rate required by the compressor flows. When the compressor 2 operates, the tooth space pressure rises, the pressure is applied to the upper part of the piston through the pulsation absorbing device 8, and the valve body 10 is pressed downward to widen the flow passage. Since the pressure of the high-pressure liquid is applied upward to the valve body, the flow passage area is determined by the relationship between this pressure and the force pushed by the piston and the adjusting spring from above, and an appropriate amount of liquid injection is possible. In this respect, in the conventional device, the flow rate was changed depending on the size of the difference between the high pressure and the tooth space pressure because only the limitation by the nozzle was used.

[0010]

As described above, according to the present invention, since the liquid injection fluid can be controlled by the flow control valve, it is possible to prevent the liquid injection amount from being excessive or insufficient and the condenser liquid level to be lowered.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view of the liquid injection flow rate control device of the present invention.

FIG. 3 is a refrigerant circuit diagram of a refrigeration apparatus using a conventional liquid injection method.

[Explanation of symbols]

 1 Evaporator 2 Compressor 3 Condenser 4 Expansion valve 7 Flow control valve 8 Pressure pulsation absorber 9 Outer box 10 Valve body 11 Adjusting spring 12 Piston 13 Cylinder 14 Connecting rod 15 Adjusting screw

Claims (2)

[Claims] 1. A liquid injection refrigeration system comprising a compressor, a condenser, an expansion valve and an evaporator, and having a refrigerant circuit for sending a part of the condensed liquid from the condenser to the compressor, wherein the condenser A refrigeration system comprising a liquid injection flow control valve and a pressure pulsation absorbing device connected to the flow control valve for monitoring the tooth space pressure of the compressor in a refrigerant circuit between the compressor and the compressor. 2. A flow control valve, a valve body for opening and closing a flow path, an adjusting spring and a piston for moving the valve body, a cylinder on which the piston slides, and an adjustment for adjusting the opening degree of the valve body. The refrigeration system according to claim 1, further comprising a screw, wherein the pulsation absorbing device applies pressure to the piston.