JPH0246862B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration system equipped with a device for controlling the amount of refrigerant circulated.

Normally, in a refrigeration cycle, the appropriate refrigerant flow rate varies depending on the evaporation temperature, and as the evaporation temperature increases, a larger refrigerant flow rate is required. When the adjustment width is small and the evaporation temperature is high, the refrigerant flow rate is insufficient, and the degree of superheating of the refrigerant at the evaporator outlet becomes too large, causing the compressor temperature to rise, and when the evaporation temperature is low, the refrigerant flow rate becomes excessive. This may cause liquid backlog in the compressor. Therefore, in order to solve these problems, a refrigeration cycle as shown in FIG. 1 can be considered.
That is, in FIG. 1, 1 is a compressor, 2 is a condenser, and 3 is a pressure reducing device, and as shown in FIG. An inner tube 34 having a shaped groove 33 is inserted thereinto. Then, the inlet pipes 35 and 36 are arranged so that the spiral groove 33 and the refrigerant flow passage 32 are parallel to each other.
The inlet pipe 36 is connected to the outlet of the condenser 2 and the inlet of the evaporator 4 (described later) via an outlet pipe 37, and the inlet pipe 36 is provided with a flow rate regulating valve 39 such as an electric expansion valve. 4 is an evaporator, and these devices 1 to 3 are sequentially connected to form a refrigeration cycle. Therefore, the compressor 1 and the condenser 2 function in the same manner as in a normal refrigeration cycle, but in the pressure reducing device 3, the liquid refrigerant supplied from the condenser 2 flows through the spiral groove 33, is depressurized, and then passes through the evaporator. 4, it evaporates and has a cooling effect. Further, a part of the liquid refrigerant supplied from the condenser 2 is depressurized by the flow rate adjustment valve 39 and evaporates in the refrigerant flow path 32 to cool the refrigerant flowing in the spiral groove 33. The flow rate of refrigerant within increases. That is,
This is because the gas content in the two-phase flow of refrigerant generated within the spiral groove 33 decreases as the amount of cooling increases, and fluid resistance decreases.
Therefore, the amount of cooling can be changed by adjusting the opening degree of the flow rate regulating valve 39. For example, by detecting the temperature at the inlet and outlet of the evaporator 4, the outlet temperature of the evaporator 4 is always slightly higher than the inlet temperature. If the flow rate adjustment valve 39 is controlled so that the refrigerant is completely gasified at the outlet of the evaporator 4 and slightly superheated, an appropriate refrigerant flow rate can always be circulated within the refrigeration cycle.

By the way, when such a device is used in a large refrigeration system, the refrigerant flow rate becomes large, so a large pressure reducing device and flow rate adjustment valve are required, which increases manufacturing costs and requires a large installation space. There were some shortcomings.

This invention was made to eliminate the above-mentioned drawbacks, and by connecting the capillary reach tube that connects the condenser outlet pipe and the evaporator inlet pipe to the inlet side of the flow rate regulating valve and the outlet side of the pressure reducing device, The aim is to obtain a small and inexpensive refrigeration device.

Embodiments of the present invention will be described below based on the drawings. In Fig. 3, 1 is a compressor, 2 is a condenser, 3 is a pressure reducing device, 4 is an evaporator, 35, 36, 3
7 is a pipe, and 39 is a flow rate regulating valve, which are the same as the conventional device shown in FIG. 40 is a capillary tube according to the present invention. This capillary tube 40 is connected to the inlet side of the flow rate regulating valve 39 and the outlet side of the pressure reducing device 3.

In the refrigeration system configured as above,
A part of the refrigerant flow rate is controlled by the capillary reach tube 40, and the remaining refrigerant is controlled by the flow rate adjustment valve 39 and the pressure reducing device 3. Therefore, even in a large refrigeration system, a small capacity flow rate adjustment valve 39 and a small pressure reducing device are used. With the device 3, the refrigerant flow rate can be appropriately controlled.

Furthermore, the present invention can be applied to refrigeration systems with different capacities by simply changing the resistance of the capillary tube 40.

Furthermore, as shown in FIG. 4, a solenoid valve 41 is provided at the inlet of the capillary tube, and when the required refrigerant flow rate of the refrigeration system is small, this solenoid valve 41 is closed and the flow rate regulating valve 3 is closed.
9 and the pressure reducing device 3 alone control the refrigerant flow rate.

Also, when the required refrigerant flow rate is large, the solenoid valve 41
By opening the refrigerant and controlling the flow rate by flowing the refrigerant through both the capillary tube 40, the flow rate adjustment valve 39, and the pressure reducing device 3, smooth flow control of a large refrigeration system can be realized.

Also, this solenoid valve 41 and capillary tube 40
The number of sets is not limited to one, but more smooth control can be achieved by using a plurality of sets.

Note that the pressure reducing device is connected to the outer tube 31 as shown in FIG.
The same effect can be obtained by inserting a capillary tube 33 in a coiled manner as a substitute for the spiral groove, and allowing the refrigerant depressurized by the flow rate adjustment valve 39 to flow around the capillary tube 33. be.

Further, although the above embodiments have been described with respect to a simple refrigeration system, in addition to such a refrigeration system, as shown in FIG. 6 or FIG. It can be applied to other refrigeration cycles such as heat pump cycles, multistage refrigeration cycles, and multistage cascade refrigerant cycles equipped with switching valves 11, etc., and can also be applied to those equipped with auxiliary equipment such as oil separators, dryers, and accumulators. It has the effect of

As described above, the present invention includes a pressure reducing device having a refrigerant flow passage and a spiral passage, each of which is connected to the other, and a pressure reduction device connected to the pressure reduction device to reduce the pressure of the refrigerant in the refrigerant flow passage to cool the refrigerant in the spiral passage. By connecting a capillary tube to the inlet side of this flow rate adjustment valve and the outlet side of the pressure reducing device, the refrigerant flow control range can be expanded, making it possible to use an inexpensive flow rate adjustment valve and pressure reduction device. This device has the effect of providing smooth flow control for large refrigeration equipment.

[Brief explanation of drawings]

Figure 1 is a conventional refrigeration cycle diagram, Figure 2 is a diagram of a conventional refrigeration cycle.
FIG. 3 is a refrigeration cycle diagram showing one embodiment of the present invention, and FIGS. 4 to 7 are diagrams showing other embodiments of the present invention. In the figure, 1 is a compressor, 2 is a condenser, 3 is a pressure reducing device, 39 is a flow rate adjustment valve, 40 is a capillary tube, and 41 is a solenoid valve. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A pressure reducing device having a refrigerant flow passage connected in parallel to each other and a spiral passage surrounding the outer periphery of the refrigerant flow passage; A flow rate regulating valve is provided for cooling the refrigerant by reducing the pressure and evaporating the refrigerant and exchanging heat with the refrigerant in the spiral passage, and a capillary reach tube is provided between the inlet side of the flow rate regulating valve and the outlet side of the pressure reducing device. A refrigeration device characterized in that: