JPS59145451A - Refrigeration cycle device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to control of an electric expansion valve provided in a refrigeration cycle device when starting a compressor.

Conventionally, there was a device of this type as shown in FIG. 1. In FIG. 0, (1) is a compressor, and (2) is a condenser.

(3) is a temperature-sensitive expansion valve, (4) is a temperature-sensitive cylinder, (5) is an evaporator, and (6) is an accumulator.

Next, the operation will be explained. When compressor +11 starts, the refrigerant compressed to high temperature and pressure by compressor (1).

It flows into the condenser (2) and exchanges heat, but since the pressure is not yet high enough, it is not sufficiently liquefied and becomes a two-phase mixture of liquid and gas, which flows into the expansion valve (3)K.

Therefore, since the refrigerant is in a two-phase state and this type of expansion valve has a small valve lift of approximately α2~0.3-, the amount of refrigerant passing through the expansion valve is extremely reduced, resulting in a decrease in the pressure on the low pressure side. As a result, the superheat increases, and the compressor increases by +1.
1 Since the specific volume of the artificial refrigerant is large, the amount of refrigerant displacement is reduced, so it takes a considerable amount of time to reach a stable state, and if the temperature condition on the high pressure side is low, the low pressure cut occurs and operation becomes impossible. .

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and when the compressor is started, the electric expansion valve is kept fully open until the peak of superheat is exceeded, and the next valve is opened. The purpose of the present invention is to provide a refrigeration cycle device that can reduce the superheat at the time of shear startup and achieve a stable state without significantly reducing the low pressure by setting the opening degree to this peak value. There is.

An embodiment of the present invention will be described below with reference to the drawings. Second
In the figure, (7) is an electric expansion valve, and (8) is a bypass path that bypasses both sides of the electric expansion valve (7) to the inlet of the shear achievator (6).
A capillary tube is provided as a. Ql is the first temperature sensor installed at the exit of the bypass path, (10 is the Achiemulator (6) inlet side (bypass connection part and evaporator side)
The second temperature sensor 63 provided in the first and second temperature sensors α1α0 and a relay (not shown) for starting and stopping the compressor (1) are connected to the electric expansion (5). A controller that controls the valve (7), +11 is a lead wire. The rest of the configuration is similar to that of the conventional device shown in FIG. Figure 3 shows the structure of the electric expansion valve (7), where Oll is the electromagnetic coil, (to) is the plunger, &
L is a cylinder with a slit (b). (
) is the piston, 0un is the spring, (to) (to) is the refrigerant pipe, and when a current is input from the controller 02 to the lead wire (Il), the electromagnetic coil C (I) is programmed in proportion to the energized current. A force is generated to pull the jar (A) in the direction of the arrow, and the spring (to) becomes 0.
It stops at a balanced position due to the force relationship with 71. Therefore, as the applied current increases, the plunger (a) and the piston (to) move to the stop position ft in the direction of the arrow, and the opening area of the slit provided in the cylinder (to) increases. Figure 4 also shows the electric expansion valve (7) when the compressor is started.
Figure 5 shows the correlation between the peak of superheat sh at startup and the stable refrigerant flow rate G when the valve opening of the electric expansion valve ( 7)
First, the operation during steady operation will be explained, which shows the correlation with the valve opening vx. The refrigerant vapor that has become high temperature and high pressure in the compressor fil undergoes heat exchange (4) in the condenser (2), becomes liquid, and flows into the expansion valve (7). The pressure is then reduced by the expansion valve +71, resulting in low temperature and low pressure in the evaporator (5
), the heat is exchanged and the resulting superheated steam is sent to the accumulator (6).
forming a circulation cycle through which the compressor returns to the compressor (1).

On the other hand, from both sides of the electric expansion valve (7),
) The refrigerant passing through the bypass passage (8) that bypasses the inlet has a higher pressure when connected to the condenser (2) side, so some of the refrigerant passes through the outlet side of the electric expansion valve (7) (the evaporator ( 5) side)
The pressure is reduced to the inlet pressure of the shear accumulator (6) through the two capillary tubes (9), and the pressure is reduced to a two-phase state.
It is mixed with the heated steam coming out of the evaporator (5) and sent to the accumulator (
6) and return to the compressor (1). Therefore, the bypass path (8
) is equal to the refrigerant pressure at the inlet of the accumulator (6), so the temperature of this part becomes the saturation temperature of the inlet pressure of the accumulator (6). Therefore.

Place the first temperature sensor (IQ near the exit of the bypass path).

Also, since the second temperature sensor αD is provided on the inlet side of the air conditioner (6), the controller a can calculate the superheat (t) of the refrigerant at the inlet of the air conditioner (6) based on the detection value of both temperature sensors αD. Then, from this amount of superheat, a current for adjusting the opening degree of the electric expansion valve (7) is outputted to control the amount of superheat to a predetermined amount.

Next, the startup of compressor +11 will be explained. When the electric expansion valve (7) is kept fully open during startup, as shown in FIG. 4, when the stable refrigerant flow rate is large, the superheat (sh) at startup becomes large.

Also, the valve opening degree when stable is as shown in Figure 5.

It can be seen that the larger the flow rate G is, the larger the valve opening degree X is. Therefore, when the peak sh of superheat is large, the valve opening degree during stability is also large. When the compressor +11 is started, a relay that detects whether the compressor (!) starts or stops works, and the controller A sends a large current to the electric expansion valve (7) to fully open the valve. The superheat on the inlet side of the accumulator (6) detected by the temperature sensor as an is due to the fact that the refrigerant that had accumulated in the evaporator (5) returns to the compressor (11 side) when it is stopped, so this liquid returns. During this time, the detected value is zero superheat.Then, on the other hand, the refrigerant leaving the compressor +11 undergoes heat exchange in the condenser (2), but because the pressure is not high enough, it does not completely liquefy and becomes a two-phase state. The flow flows into the electric expansion valve (7), but since the valve opening is fully open, the flow rate does not decrease drastically.Therefore, the pressure drop on the low pressure side is small, and the peak value of superheat is also reduced by temperature-sensitive expansion. If it is made smaller than the valve, it can be damaged.At startup, the amount of sys-per heat increases, and even if it reaches a predetermined value, the electric expansion valve (7)
The valve opening is not controlled and is left fully open until it reaches its peak.
When the superheat detected by the temperature sensor +11 all reaches its peak, the controller aS calculates the valve opening at a stable time based on this peak value, and the current value that becomes the valve opening at a stable time is calculated by the controller α. The electric expansion valve (7) outputs K for fast and stable operation.

It has a quick start-up time and enables highly efficient operation.

In the above embodiment, as soon as the superheat at startup reaches its peak, a current value that corresponds to the valve opening at a stable state is output to the electric expansion valve (7). It may also be a device (7) that outputs a current value that becomes the valve opening degree in a stable state gradually to the electric expansion valve (7) after a period of time equivalent to the time to the peak of heat. Furthermore, the temperature sensor 611 may be provided at a position that detects the temperature of the piping near the compressor suction.

As described above, according to the present invention, when the compressor is started.

The valve opening of the expansion valve is kept fully open until the peak of superheat, and the controller calculates and sets the valve opening when stable based on this peak value, so the drop in low pressure at startup is small and superheat is maintained. The peak value can be made very small, the low pressure does not drop too much, and the valve opening can be quickly reached when it is stable, so the start-up is quick and highly efficient operation is possible.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram of a conventional refrigeration cycle device. Fig. 2 is a refrigerant circuit diagram of a refrigeration cycle device showing one embodiment of the present invention, Fig. 3 is a structural sectional view of an electric expansion valve, and Fig. 4 is a sectional view of the structure of an electric expansion valve.
The figure is a characteristic diagram showing the relationship between the peak value of super heat 8 hours and the stable refrigerant flow rate G when the compressor startup electric expansion valve is fully open. Figure 5 shows the relationship between the stable refrigerant flow rate G and the electric FIG. 3 is a characteristic diagram showing the relationship between the expansion valve and the valve opening degree X. FIG. (8) The same symbols in the figures indicate the same or corresponding parts. 11 is a compressor, (2) is a condenser, (3) is a temperature-sensitive expansion valve, (5)
is an evaporator, (6) is an accumulator, and (7) is an electric expansion valve. (8) is a bypass path, (9) is a capillary, Hall is a temperature sensor, and α is a controller. Agent Shin Kuzuno - 11g 162 Figure 8 Figure 4' Flow jQ 5th diagram, b, 4 6 Procedural amendment (method) 1. Indication of case Patent Application No. 1987-19123 2.
Title of the invention: Refrigeration cycle device 3, relationship with the case of the person making the amendment Patent applicant address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Hitoshi Katayama 4, Agent Person 5. Date of amendment order: May 31, 1980 6. Subject of amendment + 11 Full text of specification = Person 4 7. Contents of amendment (1) Full text of specification / '111 $1 is transcribed as shown in the attached sheet. (No change in content) 8. Attached documents + 11 Statement meeting = Vinegar or more

Claims (1)

[Claims] In a refrigeration cycle device in which a compressor, a condenser, a purchase air expansion valve, an evaporator, and an accumulator are sequentially connected and disconnected, either side or one of the electric expansion valves is connected to the inlet of the shear accumulator, and A bypass path provided with a pressure reduction mechanism, a first temperature sensor that detects the outlet temperature of this bypass path, a second temperature sensor that detects the accumulator inlet or compressor inlet temperature, and a detector that detects whether the compressor starts or stops. , above No. 1. The amount of superheat at the inlet of the accumulator is calculated based on the detection value of the second temperature sensor to control the opening of the electric expansion valve, and when the compressor is started up, the electric A refrigeration cycle device characterized by comprising a controller that fully opens an expansion valve until the amount of superheat exceeds a peak value.