JPS58214755A - Method of controlling cooling 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 In a cooling circuit in which a compressor ■, a condenser ■, an expansion valve ■, and an evaporator ■ are connected to piping ■■■ and ■ as shown in FIG. ■ is the pressure ps in the refrigerant inlet pipe ■ of the evaporator ■ or the refrigerant outlet pipe ■
The internal pressure p@g and the outer surface temperature 'I'ot' of the pipe ■ are detected by a gas expansion type detector, and the temperature Te! ' is measured body pressure Pez' [summer change Pe+ or Pe! Ks on one side of the diaphragm, and P on the other side of the diaphragm.
E! ' to work (intervention 2'-pes) or (
The diaphragm was moved to the y position in proportion to the magnitude of the diaphragm (pet' - Pex), and the needle valve was opened and closed by the movement K to control the amount of refrigerant circulation.

In such an expansion valve, the opening/closing stroke of the needle valve is only about 0.5 a, so even a slight change in the needle valve position will cause a large amount of flow ashing, and the flow rate control range is narrow, so the cooling load will be reduced. When the refrigerant flow rate is close to the rated value, the refrigerant flow rate is controlled smoothly, but when the cooling load is significantly smaller than the rated value, the so-called hunting phenomenon occurs in which the needle valve repeatedly moves between closing and fully opening, or when the cooling load is lower than the rated value. When the load is higher than the load, there is a problem in that even if the needle valve is fully opened, the necessary amount of refrigerant cannot pass through.

Furthermore, as in a car cooler, the compressor (■) is connected to the vehicle's running engine by a belt or the like, and the engine rotational speed varies from 600 to 600, depending on the vehicle's running condition.
GO rpm wide range: In case of liquefaction, compressor■
Since the ratio of the maximum and minimum compression capacity of the engine will be 10 times higher, it is extremely difficult to expect that the cooling system including the compressor, condenser, expansion valve, and evaporator will operate in a well-balanced manner. It was impossible.

Although many efforts have been made to provide a comfortable cooling sensation even under such wide range of conditions, a complete solution has not yet been reached. When the speed is high, busyness has the following problems.

α) Since the compressor rotates at extremely high speed and circulates a large amount of refrigerant, the liquid refrigerant that has not been completely evaporated in the evaporator returns to the compressor. (b) The compressor rotates at an extremely high speed and forcibly sucks refrigerant from the evaporator, resulting in damage to the piston and valves of the compressor. As the pressure inside the steamer (2) decreases, the temperature of the steamer (2) may also drop to, for example, below -15°C. Therefore, moisture in the air is trapped on the outer surface of the evaporator ■! Otherwise, there is a problem in that the heat exchange capacity of the evaporator (2) is reduced and the internal pressure and temperature of the evaporator (2) are further reduced, leading to further frost formation.

(c) When the pressure inside the evaporator ■ drops abnormally or the temperature Tr inside the vehicle compartment drops, the clutch that transmits power from the engine to the compressor opens and stops the compressor ■. However, in such cases, the frost or ice that has adhered to the evaporator (2) melts, or the water that has landed on the evaporator (3) is blown out into the passenger compartment, resulting in "fog spraying". In order to control the temperature in the passenger compartment, when the compressor ■ is started and stopped frequently, the compressor ■ starts and stops. It is well known that the air that is blown into the cabin of the vehicle through the automatic generator ■ for a while after the vehicle has come to a stop has a unique odor that causes discomfort to passengers.

Therefore, many car drivers operate the compressor continuously, use the evaporator to constantly cool and dehumidify, and either reheat it with a heater or mix it with warm air from outside the car to reach a comfortable blowing temperature. However, since this method is extremely energy-consuming, it has the problem of significantly reducing the fuel consumption of the automobile and further deteriorating the acceleration and driving performance of the automobile.

The present invention is intended to solve these problems, and as shown in FIG. In a cooling circuit in which a refrigerant such as fluorocarbon is sealed in a system that is cyclically connected by
At the same time, a part of the discharge pipe (■) of the compressor (■) is guided to the tank 0, a heat exchange part (phase) is formed in the tank (0), and then connected to the condenser (■), and the evaporator (■) is connected to the condenser (■). The temperature of the controlled object Illr sent to the evaporator, the refrigerant inlet temperature Tel to the evaporator, the refrigerant outlet temperature Te3, etc. are detected from the detected body weight, and the detected values are input into a calculation means such as a microcomputer, for example, as shown in Table 1. As illustrated in Table 2 and Figure 8, the operating modes of C1 compressor ■, blower ■, proportional control expansion valve [phase], and proportional control bypass valve are determined by comparison with preset reference values. (2) It is configured to control the opening degrees of (1) in relation to each other. This is a method of controlling a cooling circuit.

To explain the present invention in more detail, as shown in Table 1, the mode K and compressor ■ (or symbol C) are selected to either W or Alternatively, for the symbol F), the W mode can be manually selected, and for modes other than W, X, ¥, or Z is selected based on the computer's judgment in FIG.

In addition, the proportional control type expansion valve @ (or symbol LFJ) and the proportional control type bypass valve O (or symbol LB) are the 8th
Either W or XY is selected by the computer shown in the figure.

The computer calculation and determination program illustrated in FIG. 8 is a concrete implementation of the operation plan illustrated in Table 2. Note that when the W mode is manually selected for the air blower *F, the entire cooling system is planned to stop.

The characteristic feature in Table 2 is that pattern Nagi 4.5.1
0 and 11, the operation mode of the expansion valve LE is set to YK. If you use a conventional constant superheat expansion valve, these Jl! ! In the J table condition, ΔTe≦5, so the structural principle is that only mode This allows for optimal control without being subject to constraints.

Next, when an example of the operation in Table 2 and FIG. has been done.

That is, if we follow the order of these calculations in Figure 8, - (a) Input Tr = 29°C read 61ff) Input Te, = -2°C read (c) Input 'peg = 9°C read ) Calculation Δ1°e
== 'fog -Tel = 11 deg(E)
Judgment Is Tr≧26″C?- Since τITL3, proceed to the downward arrow in Figure 3.
Judgment Is T town ≦ o'c? −・ Since it is YKS, proceed to the downward arrow in Figure 8 (υ judgment
T012 10°C? - Since YES, proceed to the downward arrow in Figure 8 (→ Judgment
△Tl≧5 deg? - YES Judgment to proceed to the downward arrow in Nano-1' Figure 8 Is ΔTe≦10 dog? - Since it is No, it moves to the left in Figure 8) Judgment Is Tr≦28℃? - Since it is No, proceed to the left in Fig. 8) The judgment result is pattern positive 9, and proceed further according to the arrow (W) C output (C=X) 1. y output (F=Z), LE
Output commands are issued in the order of high output IJ=W) and LB ratio output LB=X).

(W) Next, return to the start and read the next Tr again.

In the above description, when the bypass valve @ is opened, a part of the refrigerant returned from the evaporator (2) to the compressor (2) enters the tank (2) and comes into contact with the heat exchange section (0). The high-temperature refrigerant discharged from the compressor ■ is flowing in the heat exchange section 0, so the refrigerant that returns from the evaporator ■ to the compressor ■ is heated in the tank 0 and completely vaporized. It is sucked into the compressor ■.

On the other hand, the high-temperature refrigerant discharged from the compressor ■ loses its heat in tank 0, so the heat load on the condenser ■ decreases, which lowers the temperature and pressure of the condenser. Driving power can be reduced, resulting in energy-saving effects.

In the above operation description, a method was exemplified in which the temperature of the object to be cooled Tr, the refrigerant inlet temperature Tel to the evaporator ■, and the refrigerant outlet temperature TO2 are selected as temperature detection points and controlled as inputs to the microcomputer. The implementation method is to detect Tr, Tes+ and the refrigerant inlet temperature Tea into the compressor and input it to the microcomputer. (1) It is also possible to control the operation of the proportional control expansion valve [phase], and to control the bypass valve @ by the calculated value of (1°es-TO). By comparison, the proportional control expansion valve QΦ functions as a variable pressure type of the conventional constant pressure expansion valve, and the bypass fr■ functions as a conventional temperature type expansion valve (type that keeps the degree of superheat constant). They will be working in a similar way.

In this way, in the present invention, the compressor (■), the blower (■),
The operations of the proportional control expansion valve σΦ and the proportional control bypass valve ■ have been optimized in relation to each other, so the cooling circuit can be operated in an optimal state even when the engine speed changes significantly, ensuring comfortable operation. This book has extremely high industrial value as it improves performance, reduces energy consumption, protects the various functions that make up the cooling circuit, and furthermore minimizes the impact on vehicle driving performance.

While explaining Fig. 2, an example of a device that functions as a proportional control expansion valve [phase] and a proportional control bypass valve ■ is as follows.
As shown in Fig. 4, a valve seat O is provided in a part of the valve body 0, and the flow rate is controlled by a trap by changing the clearance with the needle valve [phase], and the valve seat O is integrated with the needle valve [phase]. The valve stem 0, the male threaded part [phase], the rotor of the motor [phase], and the bearing part [phase] are arranged in series, and the male threaded part 0 is fixed to the valve body 0 and fitted into the female thread [phase]. The bearing part [phase] is supported by the bearing meta/I/[phase] K, and the fixed coil [phase] of the motor is attached to the outside of the sealed cylinder [phase] made of non-magnetic material. can.

Therefore, each time a clockwise or counterclockwise rotation signal current is sent from the microcomputer to the fixed coil [phase] of the motor, the rotor [phase] of the motor rotates one step to the right or to the left. Due to the screw action of the male thread [phase] and the female thread [phase], the needle valve 0 rotates to the right or left and moves left or right in the direction of the axis in the same figure, and the valve seat [phase]
The gap between the two is compressed, creating pressure to control the flow rate.

[Brief explanation of the drawing]

FIG. 1 is a conventional cooling circuit diagram, FIG. 2 is a conceptual diagram of the invention's cooling circuit, FIG. 8 is an example of a control flowchart of the invention's cooling circuit, and FIG. 4 is a sectional view of a proportional control valve. ■= Compressor ■= Condenser ■: Expansion valve ■= Evaporator
■■■■0 @ [Phase] = Piping ■ = Air blower $11 6 = Proportional control type expansion valve ■ = Proportional control type Bibanu valve 0 = Tank [Phase] = Heat exchange section [Phase] = Valve body [Phase] = Valve seat [phase] = needle valve 0 = valve stem [phase] = male thread part [phase] = motor rotor [phase] = bearing part [phase] = female thread [phase] = bearing meta A/ ■ = Closed cylinder [phase]
= Motor fixed coil patent applicant Taiheiyo Kogyo Co., Ltd.

Claims (1)

[Claims] In a cooling circuit in which a refrigerant such as fluorocarbon is sealed in a system in which the compressor ■, condenser ■, proportional control expansion valve [phase], and evaporator ■ are cyclically connected by piping ■■■■, the compressor ■Pipe the bypass valve @ and tank @ in parallel with the suction side piping ■LJ! 1@ and [phase], and a part of the discharge pipe (■) of the compressor (■) is guided to the tank 4 to form a heat exchange part (phase) in the tank 0, and then the condenser (■) and Controlled object temperature Tr connected and sent to evaporator ■
, the refrigerant inlet temperature Tθ1 and refrigerant outlet temperature Tez to the evaporator ■, the refrigerant inlet temperature Te to the compressor ■, etc. are detected by the sensing body, and the detected values are input into a calculation means such as a microcomputer and set in advance. The cooling system is configured to compare and judge the operating modes of the compressor ■ and the blower ■, and the opening degrees of the proportional control expansion valve [phase] and the proportional control bypass valve 0 in relation to the mutual pressures, by comparing and determining the reference values determined by the cooling system. How to control the circuit.