JPS58133574A - Controller for refrigeration circuit - 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 improves the starting characteristics and control of a pressure reducing device of a refrigeration circuit used for air conditioning or cooling, and allows continuous operation with efficiency.

A capillary tube is generally used as a pressure reducing device in a refrigeration circuit. J! If the operating conditions of the refrigeration circuit change due to changes in the external conditions of the source and user heat exchangers, the depressurization function will not be fully utilized and the capacity will decrease. It had

Also, a refrigerator using an electric expansion valve as a pressure reducing device 10]
The disadvantage of @ is that it has a large time constant, takes time to stand up at 4 o'clock, and is not effective until it shifts to steady transmission.

This invention eliminates the drawbacks of the conventional refrigeration circuit device as described above, performs subcool control P and superheat control on the refrigeration circuit, and uses an i-type dilatation valve directly in the state pressure immersion to control the expansion valve. By adjusting the valve change, the difference between the temperature of the inlet of the pneumatic expansion well and the wall temperature of the pressure machine and the inlet pipes can be maintained within a specified range, and the operation can be carried out efficiently.
The opening/closing means stops the refrigerant flowing into the magnetic expansion °° valve when the pressure 4a machine is stopped, and maintains a low pressure difference in the refrigeration circuit when the pressure m machine stops, and speeds up the start-up time when waiting for startup. ,
The purpose is to improve the starting characteristics and to improve the efficiency from this aspect as well.

The invention of Chiko's #i is a compressor, #! A refrigeration circuit is constructed by connecting a stripe device, an electric expansion valve evaporator 4, and an accumulator to an Il[M direct inlet tally, and means for exchanging total heat with the refrigerant at the outlet of the condenser and the refrigerant at the inlet of the compressor; means for exchanging heat between the refrigerant exiting the condenser and the refrigerant at the outlet of the evaporator, which has been heat-converted by the heat exchange means;
1. An auto-closing means that closes when at rest and fully controls the flow of refrigerant to the electric expansion valve; 1. a temperature sensor that detects the temperature at the inlet of the magnetic expansion valve; and 1. the clamping machine 1. The second ^Alzu sensor that determines the level of entry and exit, and the above-mentioned
, a controller for No. 8 that calculates the difference in temperature using the second temperature sensor and adjusts the temperature of the electric expansion valve so that this temperature difference is maintained within a predetermined range. It is equipped with the following.

And its action is #! Super heat control is performed by exchanging the refrigerant at the compressor outlet with the compressor inlet refrigerant, and the refrigerant exits the condenser and exchanges heat with the refrigerant at the evaporator outlet. Perform subcool control. In this way, in a refrigeration circuit that performs super heat control and subcool control, even if the external temperature of the user side and heat source side - C two heat exchange changes, the most efficient system is used. The difference between the compressor temperature and the compressor temperature is constant. Figure 2 shows this example (when the zero circuit is used as an air conditioning system and warm-up operation is performed, the depressurization 11 that produces the maximum capacity)
The temperature difference ΔT''TI-T between the electric expansion valve inlet refrigerant temperature T and the compressor inlet refrigerant temperature T when JA is expressed is shown using the outside air temperature To as a parameter.

7J The Δ mark in the diagram indicates the variation in the X test song.

As can be seen from Figure 7g, in a refrigeration circuit that performs super heat control and cool control, ΔT is maintained within a predetermined range even if the outside temperature To ('Cl) changes. It is possible to set the difference ΔT between the inlet refrigerant temperature T, ('C) of the electric expansion valve and the inlet refrigerant temperature of the RTM machine within the above-mentioned range to achieve the capacity of V'i.

However, in a circuit that uses a capillary tube to reduce ItEf and does not perform subcool control or super heat control, the outside air temperature 'ro('
Due to the change in C), the relationship between the refrigerant temperature Tl at the inlet of the air expansion valve, which indicates the force of the trowel f#6, and the refrigerant temperature T3, which enters the compressor, changes significantly. However, even if this ΔT is controlled within a predetermined range, the line drawing ability will not be fully demonstrated regardless of the outside temperature. Therefore, in order to control this temperature difference ΔT within a predetermined range and operate the refrigeration circuit continuously at the maximum capacity regardless of the outside temperature of 4 degrees Celsius, the subcool control and super heat control become necessary conditions.

Electric expansion valves reduce the pressure of the refrigerant liquid, and can freely change the pressure reduction by an electric signal.In a capillary tube, the pressure reduction value can be changed depending on changes in external conditions. The warpage is left uncontrolled, and it is not possible to intentionally change the value to the target value.

E1. The second temperature sensor measures the electric expansion valve inlet and wall temperature, and the compressor suction kg! It detects the temperature and indirectly detects the temperature of the refrigerant flowing in each pipe.

-11" device is the magnetic expansion valve inlet refrigerant temperature TI which is indirectly detected by the above-mentioned O1 and O8 temperature sensors, respectively.
4 degree difference between the cold temperature TI at the inlet of the compressor JT'=T, --
is calculated and outputs a '-expansion signal which adjusts the degree of expansion of the electric expansion valve so that this one level falls within a predetermined range.

Also, the closed flat membrane opens when the compressor is started, and opens when the compressor is stopped. When the milling machine is stopped, the high pressure side and low pressure side of the refrigeration circuit are separated and this low pressure difference is maintained, shortening the time it takes to return to steady operation when restarting the machine, and reducing the startup time. This aims to improve efficiency at the same time.

The details of this invention will be described below based on the illustrations.

Figure f1 shows the basic refrigeration circuit of this invention, in which the compressor is shown, 12) is the condenser, (3) is the electric expansion valve, (
4) is a non-emitting device; (6) is an accumulator heat exchanger having the function of exchanging heat between the pressure-enhancing medium exiting the condenser 21 and the refrigerant at the exit of the non-emitting device 14); and 6) is the refrigerant that exits the condenser and before entering this accumulator heat exchanger r,
The above FE pongee comes out of the accumulator heat exchanger (6) 4m
A heat exchange vibrator that exchanges heat with the refrigerant entering the compressor 1! (7) is a solenoid valve. ) is connected to the motor circuit (not shown), and operates in synchronization with the driving and stopping of the motor (not shown), and is controlled to close when the compressor 111 is started and closed when the compressor 111 is stopped. +81 Fi above field shrinkage 11
1. It is useful for the artificial side piping, and the temperature of this pipe wall is detected and the temperature of the inlet refrigerant is calculated. The temperature sensor (9) of O8, which indirectly detects An oil that indirectly produces temperature TI
temperature sensor, II Keko temperature sensor +81,
(The detected value of 91 is input, and the temperature difference between the two is T.

This is a controller that calculates -T and -ΔT and issues a <S signal to adjust the valve opening of the electric expansion valve (31) so that the temperature difference ΔT falls within a predetermined range.

The controller for the refrigeration circuit configured as shown in Fig. Each time 3, the sensor (8) signal or Tsuchiki L
n sent to IQ, the temperature difference ΔT is outside the predetermined range,
When the upper limit of the predetermined range is exceeded, the electric expansion #-Ill's strength is decreased, and when it is smaller than the predetermined range, the lucid air expansion is increased to increase the darkness.
Emit K signal. The electric expansion # (31) has its valve opening degree adjusted in response to this signal.

By adjusting the amount of refrigerant flowing in this area, the navigation strength can be improved by adjusting the amount of refrigerant flowing through
Do one verse.

This embodiment is constructed as described above, and even if the outside temperature T・('C) changes, as shown in Fig. The difference between FE-inlet refrigerant temperature (T snow) and FE-inlet refrigerant temperature is within a predetermined range (7.
5°C ± 1'C), allowing for the most efficient continuous operation.Furthermore, the control device of this invention controls the air-type expansion pressure internal mechanism) so that it closes when it starts up and when it stops. Therefore, at the same time as the compressor 11) stops, the solenoid valve (7)
) closes and closes the pipe line, and the high pressure side and low pressure side are kept almost in the operating state while the compressor +11 is stopped, so as soon as the compressor fi+ is started and assisted, it becomes a steady state and starts up quickly. I can do it. Furthermore, in the above embodiment, the solenoid valve (7) is activated by detecting the start and stop of the compressor (11). When used in an air conditioner, the room temperature is detected and the compressor
d. The on-off signal of the room temperature detector to stop may also be used, and if the water is heated or cooled 1, and this water is used as a medium for various purposes, the temperature of the water is detected and the compressor 1 is activated.
Water that starts and stops 11! An on-off signal of the ml detector may also be used. Further, in the above embodiment, a solenoid valve is used as the means for opening and closing the refrigeration circuit, but even if an electric valve is used, exactly the same effect can be obtained. Furthermore, in the above embodiment, the opening and closing operations are performed in synchronization with the start and stop of the compressor, but the same effect can be expected even if the compressor is opened and closed with a slight delay from the start and stop times.

As mentioned above, this @Akira is subcool control 2
In the refrigeration circuit that performs superheat control, the valve opening degree of the one-stroke expansion valve is adjusted so that the temperature of the refrigerant at the inlet of the electric expansion valve and the refrigerant temperature at the inlet of the Tatsumugi machine is within a predetermined range, and By using an opening/closing means at the inlet of the pneumatic expansion valve, it is closed when the machine is stopped, resulting in high sales and quick start-up, as well as a high rate of sales. becomes oT&.

[Brief explanation of the drawing]

Fig. 1 is a stratification diagram of a refrigeration circuit system according to an embodiment of the present invention, and Fig. 2 is a graph showing the difference ΔT between the coolant temperature at the inlet of the single-air pump and the temperature at the compressor inlet and the outside air temperature. It is a characteristic diagram showing a relationship. The same reference numerals in the figure indicate the same or equivalent parts, 111 is pressure fii4, +21 #-1 condenser, 131 is one-stroke expansion valve, 14) blower 4, +51 is accumulator heat exchanger, (6) is heat exchanger, and (6) is heat exchanger. Replacement pipe, (7) is a solenoid valve, 11,
[91 is a breeding sensor, +lα is a control device. Figure 1 Figure 2'ro('c)

Claims (1)

[Claims] Ill A refrigeration circuit comprising a compressor, a condenser, a magnetic expansion valve, an evaporator, and an accumulator connected in series, wherein the condenser outlet refrigerant and the compressor inlet refrigerant a means for exchanging heat between the refrigerant exiting the condenser and the refrigerant at the outlet of the evaporator, the refrigerant having been heat-converted by the heat exchange flat membrane and the refrigerant at the evaporator outlet; (4) an opening/closing means that closes when the compressor is started and when it is stopped; a temperature sensor that detects the temperature of the air-type I changing valve inlet wall; and a temperature sensor that detects the temperature of the compressor. The known temperature difference between the second temperature sensor that detects A control device for a refrigeration circuit, comprising: a controller that emits a signal to adjust the refrigeration circuit. (2) The control device for a cold $11=1J road as set forth in claim 1, wherein the opening/closing means is constituted by a single magnetic valve. (31) The closing operation of the solenoid valve is performed by the output of a 4 degree detector that detects the temperature of the controlled object heated and cooled by this refrigeration Ic11 circuit and starts and stops the compressor. Refrigeration circuit controller-0 according to claim 2