KR100366450B1 - Method and device for controlling of stepping motor valve - Google Patents

Abstract

The present invention relates to a method and apparatus for controlling a stepping motor valve, and more particularly, to a stepping motor valve control method for controlling a refrigerant supply to each chamber in a refrigeration system operating a plurality of evaporators using a single compressor. Relates to a device. According to the present invention, the switching time of the three-way stepping motor valve for opening and closing the refrigerant supply to each chamber during the operation of the initial cooling cycle is set to a time when a predetermined time elapses from the initial driving time, and is controlled in time. Therefore, the present invention expects the effect of increasing the ease of valve switching and the reliability of the product.

Description

Method and device for controlling of stepping motor valve

The present invention relates to a method and apparatus for controlling a stepping motor valve, and more particularly, to a stepping motor valve control method for controlling a refrigerant supply to each chamber in a refrigeration system operating a plurality of evaporators using a single compressor. Relates to a device.

Refrigerators and freezers, such as air conditioners, refrigerators, and kimchi refrigerators, operate a cooling cycle to generate the cold air required inside the equipment. The cooling cycle generates cool air required by the device by heat exchange between the refrigerant flowing in the refrigerant flow path connected to the condenser and the evaporator, and the air.

On the other hand, in a cooling cycle using one compressor and driving two evaporators, three-way stepping motor valves are frequently used to open and close the refrigerant passage so that refrigerant discharged from the compressor can be supplied to each evaporator.

1 is a general configuration diagram of a cooling cycle using a three-way stepping motor valve.

The illustrated cooling cycle is composed of one compressor 10, one condenser 15, and a plurality of evaporators 45, 50. That is, the illustrated cooling cycle is a system in which two evaporators are cooled by driving one compressor.

The compressor 10 sucks and compresses the superheated steam evaporated by the evaporators 45 and 50 to generate high temperature and high pressure superheated steam. The condenser 15 cools the high temperature and high pressure superheated steam compressed by the compressor 10. The evaporators 45 and 50 evaporate the superheated steam cooled in the condenser 15.

Thus, the compressor 10 is connected between the plurality of evaporators 45, 50 and the condenser 15, the condenser 15 is connected between the compressor 10 and the plurality of evaporators 45, 50, The evaporators 45 and 50 are connected between the compressor 10 and the condenser 15. And a refrigerant supply passage connected to the compressor 10 from the compressor 10 to the condenser 15 and from the condenser 15 to the plurality of evaporators 45 and 50, and the plurality of evaporators 45 and 50. 13a, 13b) are formed. Therefore, the refrigerant supply flow path 13a formed in one refrigerating chamber, including the evaporator 45, uses the compressor 10 and the condenser 15 in common. In addition, the refrigerant supply passage 13b includes another evaporator 50 and uses the compressor 10 and the condenser 15 in common to form another cooling cycle.

A three-way stepping motor valve 25 is installed between the condenser 15 and the plurality of evaporators 45 and 50 to open and close the refrigerant supply passage according to the operation of each evaporator. In addition, expansion devices (35, 40) for controlling the pressure of the refrigerant flowing into the evaporator (45, 50) is installed.

The three-way stepping motor valve 25 serves to supply the refrigerant compressed by the compressor 10 to the evaporator 45 and / or 50 where the cooling cycle is driven. Therefore, when the cooling cycle of the first chamber is driven, the left side 25a of the stepping motor valve is opened to supply the refrigerant from the compressor to the evaporator 45. In addition, when the cooling cycle of the second chamber is driven, the right side 25b of the stepping motor valve is opened to supply the refrigerant from the compressor to the evaporator 45.

In other words, the cooling cycle used in the conventional refrigeration system is connected to the compressor 10, the condenser 15, the stepping motor valve 25a, the expansion device 35, the evaporator 45, and the compressor 10 again. And a second chamber connected to the compressor (10), the condenser (15), the stepping motor valve (25b), the expansion device (40), the evaporator (50), and the compressor (10). . And code 20 shows the fan. In the following description, the room including the evaporator 45 will be described as a first chamber and the room including the evaporator 50 as a second chamber.

Next will be described the operation of the conventional cooling cycle consisting of the above configuration.

As shown, the cooling cycle consists of one compressor 10 and two evaporators 45 and 50 that operate separately. Therefore, the refrigerant compressed by the compressor 10 is supplied to the two evaporators 45 and 50 side by side.

That is, when performing the control for cooling the first chamber, the stepping motor valve 25a is operated to open the refrigerant supply passage between the condenser 15 and the evaporator 45. In this case, as the refrigerant cooled in the condenser 15 is supplied to the evaporator 45 side, cold air required in the first chamber is made.

In addition, when performing control for cooling the second chamber, the stepping motor valve 25b is operated to open the refrigerant supply passage between the condenser 15 and the evaporator 50. In this case, as the refrigerant cooled in the condenser 15 is supplied to the evaporator 50 side, cold air required in the second chamber is made.

Of course, the first chamber and the second chamber are not always performed separately in a cooling operation, and sometimes the first chamber and the second chamber require a cooling function at the same time. At this time, the stepping motor valve 25a for opening and closing the refrigerant passage between the condenser 15 and the evaporator 45 and the stepping motor valve 25b for opening and closing the refrigerant passage between the condenser 15 and the evaporator 50 are opened at the same time. do.

Meanwhile, the refrigerant flowing in the refrigerant supply passage connected to the first chamber and the second chamber via the three-way stepping motor valve 25 has a high temperature and high pressure. Therefore, even within the three-way stepping motor valve 25 that opens and closes the refrigerant passages of the first chamber and the second chamber, there is a very large pressure difference between the open portion to which the refrigerant is supplied and the closed portion to which the refrigerant is not supplied.

In particular, when the initial drive is performed in a refrigeration system that is driven for the first time after launching or in a refrigeration system that has not been driven for a predetermined time, the pressure difference is caused by a refrigerant in an unstable state, so that the three-way stepping motor valve A problem arises in that the operation of switching over 25 is very difficult.

Therefore, when the system is initially driven, if the control for switching the three-way stepping motor valve 25 having a very high pressure difference between the refrigerant inlet port and the refrigerant outlet port is excessively performed, the compressor is overloaded due to excessive operation control. It also caused a problem that an error occurs in the operation of.

That is, the conventional refrigeration system using a three-way stepping motor valve, there is a problem that lowers the reliability of the product while the refrigeration system does not operate normally due to excessive valve switching control operation at the beginning of the drive.

Accordingly, an object of the present invention is to provide a stepping motor valve control method and apparatus capable of inducing a smooth switching operation of a three-way stepping motor valve even during initial driving of a refrigeration system.

1 is a configuration of a cooling cycle using a general three-way stepping motor valve,

2 is a configuration diagram for the control of the stepping motor valve according to the present invention;

3 is a control flowchart of the stepping motor valve according to the present invention;

4 is a time and pressure characteristic diagram at the time of initial driving.

Explanation of symbols on the main parts of the drawings

100,110: temperature detection unit 105: control unit

115: signal input unit 120: valve drive unit

125: 3-way stepping motor valve 130: compressor drive unit

135: compressor 140: counter

The stepping motor valve control apparatus according to the present invention for achieving the above object comprises an n-way stepping motor valve for introducing the refrigerant generated in one compressor, opening and closing the refrigerant supply to a plurality of chambers spaced apart; A counter for counting an initial cooling time;

And control means for controlling the switching of the stepping motor valve when the counted time passes the set time.

In addition, the stepping motor valve control method according to the present invention, a refrigeration system having a plurality of evaporators provided with a compressed refrigerant supplied by one compressor to evaporate, and provided with a plurality of chambers separated by installing the evaporators, respectively Recognizing a switching request of the n-way stepping motor valve for opening and closing the refrigerant supply to each chamber; Determining whether the initial cooling time has elapsed; When the set time has elapsed, controlling the switching of the n-way stepping motor valve.

Hereinafter, a method and apparatus for controlling a stepping motor valve according to the present invention will be described in detail with reference to the accompanying drawings.

First, the stepping motor valve of the present invention is a three-way valve. That is, as shown in Figure 1, the valve for opening and closing the refrigerant supply passage so that the refrigerant generated from one compressor can be supplied to a plurality of evaporators. Accordingly, the three-way stepping motor valve has a refrigerant inlet connected to a refrigerant supply passage connected to the compressor, and a refrigerant discharge outlet connected to each refrigerant supply passage connected to each evaporator. And the open / close control under the control of the control unit described below to open and close the refrigerant supply passage.

Therefore, the stepping motor valve of the present invention is a valve for controlling the supply of refrigerant to each chamber in the refrigeration system operating a plurality of evaporators using one compressor as shown in FIG. And the configuration of the refrigeration system required in the following description of the present invention will be described with reference to FIG.

2 is a configuration diagram for controlling the stepping motor valve according to the present invention.

The present invention senses the temperature of the first chamber, the first chamber temperature sensing unit 100 for generating a detection signal used as a basic signal for driving the cooling cycle of the first chamber, and the temperature of the second chamber and And a second chamber temperature detector 110 generating a detection signal used as a basic signal for driving a cooling cycle of the second chamber.

In addition, the present invention is a compressor 135 for generating a superheated steam of high temperature, high pressure by sucking and compressing the superheated steam evaporated in the plurality of evaporators (45, 50) shown in Figure 1, the compressor 135 It includes a compressor driving unit 130 for controlling the drive. And a three-way stepping motor valve 125 for opening and closing a supply flow path so that the superheated steam generated by the compressor 135 may be supplied to the first chamber and / or the second chamber, and the three-way stepping motor valve 125. It includes a valve driving unit 120 for controlling the drive.

The present invention includes a counter 140 for counting the initial cooling time according to the initial driving of the compressor 135. And a controller 105 which allows the switching of the stepping motor valve 125 when the initial cooling time counted by the counter 140 has elapsed.

That is, the controller 105 does not immediately switch the stepping motor valve 125 even if a request for switching of the stepping motor valve 125 is generated due to the need for supplying air to any chamber during the initial driving of the cooling cycle. Wait for the initial cooling time to elapse. After the initial cooling time has elapsed, the switching of the stepping motor valve 125 is controlled.

After the cooling cycle of each chamber reaches the normal orbit, the control unit 105 detects the sensing temperature of the first chamber temperature sensing unit 100 and the second chamber temperature sensing unit 110 and various other sensors (not shown). Based on the detected value of the control unit, it is determined that cold air supply to each chamber is necessary. In addition, the stepping motor valve 125 is opened to allow the refrigerant to be supplied to the cooling cycle of the chamber requiring the cold air supply.

Reference numeral 115 denotes a signal input unit. The signal input unit 115 is a configuration for applying various signals by user setting to the control unit 105.

The following describes the control operation of the stepping motor valve according to the present invention having the above configuration.

3 is an operation flowchart of the stepping motor valve according to the present invention.

When the power is supplied, the controller 105 applies a drive signal of the compressor 135 to the compressor driver 130. The compressor 135 is driven under the control of the compressor driver 130 to generate a high temperature, high pressure refrigerant (step 200). The refrigerant generated by the driving of the compressor 135 is supplied to the cooling cycle of the first chamber or the second chamber through the stepping motor valve 25 controlled to be open under the control of the controller 105.

The counter 140 counts the initial driving time from the ON operation time of the compressor 135 (step 210).

During driving of the cooling cycle, the control unit 105 inputs a detection signal of the first chamber temperature detection unit 100 or the second chamber temperature detection unit 110 and other sensors (not shown), and the current driving state. Determine the necessity of driving a cooling cycle other than the cooling cycle in the system.

When it is determined from the monitoring operation that the switching operation of the stepping motor valve 25 is necessary (step 220), the controller 105 reads out the initial driving time counted by the counter 140 (step 230).

In operation 240, it is determined whether the initial driving time read in operation 230 has elapsed.

In general, in the initial driving state of the compressor 135, the cooling cycle of the first chamber and the cooling cycle of the second chamber are not cooled. In this state, the refrigerant on the cooling cycle also has an unstable state that is not sufficiently cooled. Therefore, the cooling cycle reaches a normal state only after a predetermined time has elapsed since the compressor is initially driven, and the refrigerant circulating the cooling cycle has a stable state.

Therefore, in the determining whether the initial driving time according to the 240th step has elapsed the setting time, determining the time point until the cooling cycle currently being driven reaches the normal track.

If the set time has not elapsed in step 240, the refrigerant flowing on the cooling cycle is very unstable. In this case, the pressure difference between the refrigerant inlet and the refrigerant outlet of the three-way stepping motor valve 125 is very large. do. Therefore, the pressure difference between the refrigerant inlet port and the refrigerant discharge port of the stepping motor valve 125 is to wait until the point (ie, the point where the cooling cycle has reached the normal orbit) as low as possible.

That is, when the initial cooling time has not passed the set time (about 60 minutes to 80 minutes) in the 240 step, the initial cooling time has a predetermined time delay until the initial cooling time is reached (step 260).

When the initial cooling time reaches the set time set in step 240, the controller 105 controls the switching of the three-way stepping motor valve 125.

Therefore, when it is determined that valve switching is necessary until the set time is reached, the controller 105 outputs a signal to the valve driving unit 120 to switch the valve (Step 250).

When the valve is switched in step 250, the coolant is supplied to the chamber requiring the cool air supply while the coolant flows into the cooling cycle connected to the open side.

Thereafter, the control unit 105 controls the driving of the cooling cycle while reading the temperature of the chamber from the temperature sensing unit until the chamber in which the cooling cycle is driven is cooled (step 270).

Next, FIG. 4 is a characteristic diagram illustrating a time point at which the valve switching may be smoothly performed from the initial driving of the compressor. That is, as shown, after the initial drive of the compressor is made, it has a very high pressure state until reaching a certain point. Therefore, as in the part indicated by the ellipse, the switching time of the valve is delayed until the time when the pressure falls below a certain value is reached.

According to the present invention as described above, the switching point of the three-way stepping motor valve for opening and closing the refrigerant supply to each chamber during the operation of the initial cooling cycle in the refrigeration system using a single compressor to operate a plurality of evaporators It can be seen that the basic technical idea is to set the time at which a predetermined time elapses from the initial driving time and to control in time.

And within the scope of the technical idea of the present invention, of course, various modifications are possible to those skilled in the art.

According to the present invention as described above, it will be appreciated that the following advantages can be provided.

The present invention means that the normal operation of the valve is easy because the switching of the valve is controlled when the pressure at the valve inlet side is sufficiently lowered below the predetermined value (about 18 Kgf / cm ² ).

In addition, the present invention means that the operation efficiency of the refrigeration system is increased because the normal operation of the valve, the cooling cycle is efficiently controlled. Therefore, the present invention can also be expected to increase the reliability of the product by increasing the operating efficiency.

Claims (3)

An n-way stepping motor valve for introducing a refrigerant generated by one compressor and opening and closing the refrigerant supply to a plurality of chambers separated by space; A counter for counting an initial cooling time; And a control means for controlling the switching of the stepping motor valve when the counted time has passed the set time. The method of claim 1 wherein: The control means is a control device for a stepping motor valve, characterized in that for performing the switching of the stepping motor valve in the state that the valve switching request is recognized. In a refrigeration system having a plurality of evaporators for receiving a compressed refrigerant from a single compressor to evaporate, and having a plurality of space-separated chambers by installing the evaporators, respectively: Recognizing a switching request of an n-way stepping motor valve for opening and closing a refrigerant supply to each chamber; Determining whether the initial cooling time has elapsed; And controlling the switching of the n-way stepping motor valve when a set time has elapsed.