KR20200038103A - Refrigerator for actively opening and closing refrigerant control valve - Google Patents

Abstract

The present invention relates to a refrigerator capable of opening a refrigerant control valve when a discharge valve (D-valve) of a linear compressor is opened. According to one embodiment of the present invention, the refrigerator includes: a compressor compressing a refrigerant through the operation of a linear motor; a condenser condensing the refrigerant compressed by the compressor; an expansion instrument expanding the refrigerant condensed by the condenser by decompressing the refrigerant; an evaporator producing cold air by evaporating the refrigerant expanded by the expansion instrument; a refrigerant control valve controlling the refrigerant flowing over a cold air flow path formed from the condenser to the evaporator; and a control part calculating a phase difference between a motor current applied to the linear motor and a stroke of a piston reciprocated by the linear motor in the compressor, and controlling the refrigerant control valve based on variations of the phase difference.

Description

Refrigerator that actively opens and closes the refrigerant control valve {REFRIGERATOR FOR ACTIVELY OPENING AND CLOSING REFRIGERANT CONTROL VALVE}

The present invention relates to a refrigerator capable of opening a refrigerant control valve at a time when a discharge valve (D-Valve) of a linear compressor is opened.

The refrigerant in the refrigerator circulates sequentially through the compressor, condenser and evaporator according to the refrigeration cycle. The refrigerant control valve is located on a cold air passage connecting a compressor, a condenser, and an evaporator to allow and block the flow of refrigerant or to control the amount of refrigerant.

Meanwhile, a linear compressor that compresses refrigerant through a linear reciprocating motion of a piston is applied to a recent refrigerator.

The linear compressor is provided with a discharge valve (D-Valve) that supplies refrigerant compressed by the piston to the condenser. Since the discharge valve is opened only when the refrigerant is compressed to a predetermined pressure or higher by the piston, a time difference (hereinafter, D-Valve delay time) occurs at the time of driving of the compressor and when the discharge valve is opened.

When only one of the discharge valve and the refrigerant control valve is opened, the refrigerant does not circulate properly, so the conventional refrigerator opens the refrigerant control valve after the D-Valve delay time from the starting point of the compressor for efficient refrigerant circulation.

The D-Valve delay time varies depending on the operating conditions of the compressor and the outside temperature. For example, as the outside temperature increases, the pressure applied from the outside of the discharge valve to the inside of the compressor increases, so the D-Valve delay time increases, and as the outside temperature decreases, the pressure applied from the outside of the discharge valve to the inside of the compressor decreases. D-Valve delay time is reduced.

However, the conventional refrigerator does not take into account the D-Valve delay time, which varies depending on external factors, and opens the refrigerant control valve according to the fixed D-Valve delay time, and thus has a problem of low efficiency of refrigerant circulation.

An object of the present invention is to provide a refrigerator capable of opening the refrigerant control valve at the time when the discharge valve is opened by accurately grasping the time when the discharge valve is opened.

In addition, an object of the present invention is to provide a refrigerator capable of removing electrical disturbances and measurement errors in grasping the time when the discharge valve is opened.

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. In addition, it will be readily appreciated that the objects and advantages of the present invention can be realized by means of the appended claims and combinations thereof.

The present invention can accurately determine the time when the discharge valve is opened by calculating the phase difference between the stroke of the piston and the motor current, and identifying the point of inflection of the phase difference, and when the discharge valve is opened by opening the refrigerant control valve at the point of inflection of the phase difference. The refrigerant control valve can be opened.

In addition, the present invention calculates the amount of change in the phase difference after a certain time has elapsed from the start time of driving the compressor, and discharge valves by placing a predetermined interval between the calculation time of the first phase difference and the second phase difference that is the basis for calculating the amount of change in the phase difference Electrical disturbance and measurement error can be eliminated in grasping the timing of opening.

The present invention has the effect of accurately grasping the time when the discharge valve is opened and opening the refrigerant control valve at the time when the discharge valve is opened, thereby opening the refrigerant control valve at the optimal time and thereby improving the efficiency of refrigerant circulation. have.

In addition, the present invention has the effect of accurately determining the opening time of the refrigerant control valve by removing electrical disturbances and measurement errors in determining when the discharge valve opens.

In addition to the above-described effects, the concrete effects of the present invention will be described together while describing the specific matters for carrying out the invention.

1 is a view showing the configuration of a refrigerator according to an embodiment of the present invention.
2 is a view showing a control flow of a refrigerator according to an embodiment of the present invention.
3 is a view for explaining a control flow between the compressor and the control unit shown in FIG. 2;
4 is a cross-sectional view showing an exemplary configuration of the compressor shown in FIG. 1;
5 is a view showing a stroke and a phase difference that changes with time from a driving point of the compressor.
6 is a view for explaining a method of calculating the phase difference shown in FIG. 5;
7 is a flowchart illustrating a method for controlling a refrigerant control valve according to an embodiment of the present invention.

The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, and accordingly, a person skilled in the art to which the present invention pertains can easily implement the technical spirit of the present invention. In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

In the following, the arrangement of any component in the "upper (or lower)" or "upper (or lower)" of the component means that any component is disposed in contact with the upper surface (or lower surface) of the component. In addition, it may mean that other components may be interposed between the component and any component disposed on (or under) the component.

Also, when a component is described as being "connected", "coupled" or "connected" to another component, the components may be directly connected to or connected to each other, but other components may be "interposed" between each component. It should be understood that "or, each component may be" connected "," coupled "or" connected "through other components.

The present invention relates to a refrigerator capable of opening a refrigerant control valve at a time when a discharge valve (D-Valve) of a linear compressor is opened.

Hereinafter, a control method of a refrigerator and a refrigerant control valve according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7.

1 is a view showing the configuration of a refrigerator according to an embodiment of the present invention, and FIG. 2 is a view showing a control flow of the refrigerator according to an embodiment of the present invention. In addition, FIG. 3 is a view for explaining a control flow between the compressor and the control unit shown in FIG. 2.

4 is a cross-sectional view showing an exemplary configuration of the compressor shown in FIG. 1.

5 is a view showing a stroke and a phase difference that changes with time from a driving time of the compressor, and FIG. 6 is a view for explaining a method of calculating the phase difference shown in FIG. 5.

7 is a flowchart illustrating a method for controlling a refrigerant control valve according to an embodiment of the present invention.

1 to 3, the refrigerator 1 according to an embodiment of the present invention may include a plurality of components for circulating a refrigerant according to a refrigeration cycle. More specifically, as shown in FIG. 1, the refrigerator 1 according to an embodiment of the present invention includes a compressor 10, a condenser 20, an expansion mechanism 30, an evaporator 40, and a refrigerant control valve 50 ), A dryer 70 and a heat dissipation fan 80, and a control unit 60 for controlling the above-described components.

The refrigerator 1 shown in FIG. 1 is according to one embodiment, and its components are not limited to the embodiment shown in FIG. 1, and any configuration known in the art as a means for forming a refrigeration cycle It may further include an element.

According to the refrigeration cycle, the compressor 10 can compress the refrigerant, the condenser 20 can condense the refrigerant compressed in the compressor 10, and the dryer 70 is the moisture among the refrigerant condensed in the condenser 20 , Foreign matter, oil, etc. can be removed. In addition, the expansion mechanism 30 may expand the refrigerant passing through the dryer 70 under reduced pressure, and the evaporator 40 may generate cold air by evaporating the expanded refrigerant in the expansion mechanism 30.

As such a refrigeration cycle is repeated, cold air may be supplied to the interior of the refrigerator 1.

The refrigerant control valve 50 may regulate refrigerant circulating according to the refrigeration cycle. More specifically, the refrigerant control valve 50 is provided at an arbitrary position on the cold air flow path L through which the refrigerant flows to control the flow of the refrigerant. For example, as illustrated in FIG. 1, the refrigerant control valve 50 flows through the coolant flow path L formed from the condenser 20 toward the evaporator 40 under the control of the control unit 60. And allow or control the amount of refrigerant.

The heat dissipation fan 80 is installed adjacent to the condenser 20 to allow air to flow into the condenser 20 to perform a heat dissipation operation on the condenser 20. On the other hand, although not shown in the drawing, the refrigerator 1 of the present invention may further include an evaporation fan, and the evaporation fan may remove moisture generated from the surface of the evaporator 40 by introducing air into the evaporator 40. .

In the present invention, the compressor 10 may be a linear compressor that compresses refrigerant through a linear reciprocating motion.

Accordingly, the compressor 10 includes a cylinder 120 forming a compression space P of the refrigerant, a piston 130 reciprocating inside the cylinder 120, and a linear providing driving force to the piston 130 A motor 13 and a discharge valve 160 for discharging the compressed refrigerant in the compression space P may be included.

Referring to FIG. 4, in one example, the compressor 10 includes a cylindrical shell 101, a cylinder 120 provided inside the shell 101, and an axial reciprocating motion in the axial direction inside the cylinder 120. It may include a piston 130 and a linear motor 13 that provides a driving force to the piston 130.

The compressor 10 may be provided with a suction unit 104 through which refrigerant is introduced and a discharge unit 105 through which compressed refrigerant is discharged from inside the cylinder 120, and the suction unit 104 and the discharge unit ( 105) may be coupled to the shell 101, respectively. The refrigerant sucked through the suction unit 104 may flow into the piston 130 through the suction muffler 150.

The piston 130 may reciprocate within the cylinder 120 according to the driving force provided by the linear motor 13.

A compression space P in which the refrigerant is compressed by the piston 130 may be formed inside the cylinder 120. In addition, a suction hole 133 for introducing refrigerant into the compression space P may be formed in the front portion of the piston 130, and a suction hole 133 is selectively opened in front of the suction hole 133. Valve 135 may be provided.

A discharge valve 160 for discharging the compressed refrigerant in the compression space P may be provided at the front of the compression space P when the pressure of the compression space P is equal to or greater than a preset pressure (hereinafter, discharge pressure). In addition, the front of the compression space (P) may be provided with a valve spring 161 to impart an axial elastic force to the discharge valve 160, and a stopper 162 to limit the amount of deformation of the valve spring 161.

Accordingly, the compression space P may be defined as a space formed between the suction valve 135 and the discharge valve 160. In other words, the intake valve 135 may be provided on one side of the compression space P, and the discharge valve 160 may be provided on the other side of the compression space P.

The discharge valve 160 may be coupled to the valve spring 161, and the rear surface of the discharge valve 160 may be supported on the front surface of the cylinder 120.

When the piston 130 reciprocates inside the cylinder 120, when the pressure of the compression space P is lower than the discharge pressure and the suction pressure, the suction valve 135 is opened to allow refrigerant to be sucked into the compression space P You can. Subsequently, if the pressure in the compression space P is greater than or equal to the suction pressure, the refrigerant in the compression space may be compressed while the suction valve 135 is closed.

When the pressure of the compression space P becomes greater than or equal to the discharge pressure, the valve spring 161 is deformed to open the discharge valve 160, and the refrigerant may be discharged from the compression space P. The discharged refrigerant may be discharged through the loop pipe 165 to the discharge unit 105.

Meanwhile, the compressor 10 may further include a frame 110. The frame 110 is a configuration for fixing the above-described cylinder 120, it can be fastened to the cylinder 120 through a separate fastening member. The frame 110 may be disposed to surround the cylinder 120, and accordingly, the cylinder 120 may be accommodated inside the frame 110.

The linear motor 13 is fixed to the frame 110, and the outer stators 141, 143, and 145 are disposed to surround the cylinder 120, and the inner stators are spaced apart inside the outer stators 141, 143, and 145. 148 and a permanent magnet 146 positioned in the space between the outer stators 141, 143, and 145 and the inner stator 148.

The permanent magnet 146 may linearly reciprocate by an electromagnetic force formed between the outer stators 141, 143, and 145 and the inner stator 148. Here, the permanent magnet 146 may be composed of a magnet having a single pole or a plurality of magnets having three poles.

The permanent magnet 146 may be coupled to the piston 130 through a connecting member 138. Accordingly, the piston 130 may reciprocate in the axial direction together with the permanent magnet 146 according to the reciprocating motion of the permanent magnet 146 described above.

In the above, the compressor 10 has been described taking the structure shown in FIG. 4 as an example. However, the compressor 10 of the present invention discharges the refrigerant compressed above a certain pressure (for example, the discharge pressure) by the piston 130 that linearly reciprocates in addition to the structure shown in FIG. 4 through the discharge valve 160 It can be made of any structure.

The control unit 60 calculates the phase difference between the stroke of the piston 130 reciprocating within the compressor 10 by the linear motor 13 and the motor current applied to the linear motor 13, and based on the change amount of the phase difference The refrigerant control valve 50 can be controlled.

Referring back to FIG. 3, the above-described compressor 10 may include a power supply unit 11, a driving unit 12, a linear motor 13, a current detection unit 14, and a voltage detection unit 15.

The power supply unit 11 may provide power to the driving unit 12, and the driving unit 12 may provide the linear motor 13 with a motor voltage according to a command value (hereinafter, a stroke command value) for the stroke of the piston 130. You can.

For example, the power supply unit 11 may be a DC voltage source that supplies a DC voltage of a constant size. Further, the driving unit 12 may be an inverter that converts the DC voltage provided from the power supply unit 11 into an AC voltage of a predetermined size through a switching operation according to the stroke command value and provides it to the linear motor 13.

The current detector 14 can detect the motor current applied to the linear motor 13, and the voltage detector 15 can detect the motor voltage applied to the linear motor 13.

The above-described driver 12, current detector 14 and voltage detector 15 may be formed on a single chip in the form of one control module.

When the driving condition of the compressor 10 is satisfied, the control unit 60 may apply a driving signal to the driving unit 12, and accordingly, the compressor 10 may be driven.

The compressor 10 may be provided in the interior of the refrigerator 1. The controller 60 may measure the inside temperature of the refrigerator 1 in real time, and determine that the driving condition of the compressor 10 is satisfied when the measured inside temperature exceeds the required temperature for refrigeration (or refrigeration).

When the driving condition of the compressor 10 is satisfied, the control unit 60 may apply a driving signal to the driving unit 12. For example, when the driving unit 12 is an inverter including a plurality of power switching elements, the control unit 60 may apply a pulse width modulation (PWM) signal to the power switching elements.

The driving unit 12 may drive the compressor 10 by converting a DC voltage into an AC voltage having a predetermined size and applying it to the linear motor 13 according to the driving signal provided from the control unit 60.

After the compressor 10 is driven, the control unit 60 may calculate the stroke of the piston 130 based on the motor current and the motor voltage detected from the current detection unit 14 and the voltage detection unit 15. More specifically, the controller 60 may calculate the stroke of the piston 130 using the following [Equation 1].

Here, x is a stroke, α is a motor constant or a back EMF constant, V _m is a motor voltage, i _m is a motor current, R is a resistance, and L is an inductance.

The method for calculating the stroke using the above-mentioned [Equation 1] is widely known in the art, and a detailed description thereof will be omitted here.

Subsequently, the control unit 60 may calculate the phase difference between the calculated stroke and the motor current detected by the current detection unit 14. More specifically, the control unit 60 may calculate the phase difference by comparing the phase value of the calculated stroke with the phase value of the motor current.

The piston 130 may reciprocate according to an alternating current (motor current) applied in the form of a sinusoidal wave to the linear motor 13. Accordingly, the stroke of the piston 130 may also be calculated in the form of a sinusoidal wave in which positive and negative values are repeated over time.

The controller 60 may determine the difference between the phase value of the stroke calculated at a certain time point and the phase value of the motor current detected at the time point as a phase difference.

Since the stroke is caused by the motor current, the phase of the stroke may be later than the phase of the motor current. Accordingly, the control unit 60 may calculate the phase difference by subtracting the phase value on the stroke from the phase value of the motor current.

The control unit 60 may calculate a change amount of the phase difference according to a predetermined cycle, and open and close the refrigerant control valve 50 based on the change amount of the phase difference. Here, the change amount of the phase difference may be a change amount over time of the phase difference between the stroke and the motor current.

Referring to FIG. 5, the phase difference for a certain period of time (t1 to t2) from the driving time t1 of the compressor 10 may be calculated as a garbage value due to electrical disturbance in the initial stage of driving.

Thereafter, as the stroke of the piston 130 increases, the pressure in the compression space P described with reference to FIG. 4 increases and the phase difference between the stroke and the motor current may gradually decrease.

At a point in time t4 when the pressure in the compression space P increases and becomes equal to the discharge pressure, the discharge valve 160 is opened (D-Valve Open), and the phase difference between the stroke and the motor current increases to a certain point in time (t5). The phase difference can be maintained at 90 ^o .

Referring again to FIG. 6, the phase difference between the stroke and the motor current at the time t3 of FIG. 5 in which electrical disturbance is removed may be calculated to be about 60 ^o . Thereafter, the phase difference may be gradually reduced and the phase difference may be calculated as about 30 ^o at a time t4 when the pressure of the compression space P becomes equal to the discharge pressure. Thereafter, the phase difference may be gradually increased, and a phase difference after a time t5 after a predetermined time has passed since the discharge valve 160 is opened may be calculated as 90 ^o .

The controller 60 may calculate the amount of change in the phase difference after a preset time from the start time of the driving of the compressor 10 in order to take into account electrical disturbances occurring at the beginning of the driving of the compressor 10.

Referring to FIG. 5, the control unit 60 may calculate a change amount of the phase difference from a starting point t2 after a preset time t2-t1 from a starting point t1 of the compressor 10. Accordingly, since the amount of change in the phase difference is calculated after the time t2, it is possible to prevent electric disturbances occurring at the initial stage of driving of the compressor 10 from being used as a control parameter for the refrigerant control valve 50.

Meanwhile, the preset time may be differently determined according to the performance of the compressor 10, or may be determined in advance by experiment.

In addition, in order to take into account the error of the phase difference measurement, the controller 60 phase difference with time based on the first phase difference calculated at the first time point and the second phase difference calculated at the second time point after the reference time from the first time point You can calculate the amount of change.

Referring to FIG. 5 again, the phase difference may increase as a whole from a time t2 when a preset time has elapsed at a starting time t1 of the compressor 10 to a time t4 when the discharge valve 160 is opened. However, the phase difference may decrease in some sections due to measurement errors.

The controller 60 calculates the phase difference calculated at the first time point t _a and the second time point t _b after the reference time d from the first time point ta in consideration of measurement errors occurring in some sections The amount of change in the phase difference can be calculated based on the phase difference.

More specifically, the controller 60 may calculate the amount of change in the phase difference according to Equation 2 below.

는 위상차의 변화량,

는 제2 시점에 산출된 위상차,

은 제1 시점에 산출된 위상차, d는 제2 시점과 제1 시점의 시간 차(기준 시간)를 의미한다. 여기서, 기준 시간(d)은 측정 오차를 방지할 수 있는 충분한 시간으로 미리 설정될 수 있으며, 실험에 의해 미리 결정될 수도 있다.here

Is the amount of change in phase difference,

Is the phase difference calculated at the second time point,

Is a phase difference calculated at the first time point, and d is a time difference (reference time) between the second time point and the first time point. Here, the reference time (d) may be set in advance to a sufficient time to prevent measurement errors, it may be determined in advance by experiment.

By calculating the amount of change in the phase difference at intervals of the reference time, it is possible to prevent the measurement error for the phase difference from being used as a control variable for the refrigerant control valve 50.

As described above, the present invention can accurately determine the opening time of the refrigerant control valve 50 to be described later by removing electrical disturbances and measurement errors in grasping the time when the discharge valve 160 is opened.

The controller 60 may identify a point of inflection of the phase difference based on the amount of change in the phase difference, and control the refrigerant control valve 50 at the identified inflection point.

Referring to FIG. 5 again, the phase difference calculated from the time t2 may decrease until the time t4 when the discharge valve 160 is opened, and then increase again after the time t4. Accordingly, the sign of the amount of change in the phase difference can be inverted at time t4.

In other words, the amount of change in the phase difference from the time t2 to the time t4 may have a negative sign, and the amount of change in the phase difference after the time t4 may have a positive sign. At this time, the control unit 60 may identify a time point in which the amount of change in the phase difference changes from negative to positive as the inflection time, and may control the refrigerant control valve 50 at the identified inflection time.

If the refrigerant control valve 50 is opened before the discharge valve 160 is opened, a problem may occur in that the effect of maintaining the power on the cold air passage L decreases until the discharge valve 160 is opened. . On the other hand, when the refrigerant control valve 50 is opened after the discharge valve 160 is opened, a problem that the refrigerant is not circulated on the cold air passage L may occur until the refrigerant control valve 50 is opened. have.

In order to prevent this problem, the control unit 60 may open the refrigerant control valve 50 at the inflection point when the discharge valve 160 is opened. Accordingly, the discharge valve 160 and the refrigerant control valve 50 may be opened at the same time.

As described above, according to the present invention, the refrigerant control valve 50 is opened at the optimal time by opening the refrigerant control valve 50 at the time when the discharge valve 160 is opened by accurately grasping the time when the discharge valve 160 is opened. It is possible to improve the efficiency of refrigerant circulation.

Meanwhile, the control unit 60 may drive the heat dissipation fan 80 while opening the refrigerant control valve 50. The opening of the refrigerant control valve 50 and the operation of the heat dissipation fan 80 may be performed simultaneously, and may be performed within a very short time.

Refrigerant circulating through the cold air flow path (L) upon opening of the refrigerant control valve (50) can be condensed by the condenser (20), and heat generated by the condenser (20) decreases according to the operation of the heat dissipation fan (80). can do.

In addition, when the driving stop condition of the compressor 10 is satisfied, the controller 60 may stop driving the compressor 10 and close the refrigerant control valve 50.

As described above, the control unit 60 may measure the inside temperature of the refrigerator 1 in real time. The control unit 60 may determine that the driving stop condition of the compressor 10 is satisfied when the inside temperature of the refrigerator is less than the refrigeration (or refrigeration) end temperature according to the operation of the compressor 10.

When the driving stop condition of the compressor 10 is satisfied, the control unit 60 may block the driving signal applied to the driving unit 12. Accordingly, the driving unit 12 may not apply an AC current to the linear motor 13, and driving of the compressor 10 may be stopped.

In addition, when the driving stop condition of the compressor 10 is satisfied, the control unit 60 may close the refrigerant control valve 50 to block the refrigerant flow on the cold air passage L.

In addition, the control unit 60 may stop driving of the heat dissipation fan 80 while closing the refrigerant control valve 50. Closing the refrigerant control valve 50 and stopping the operation of the heating fan may be simultaneously performed, and may be performed within a very short time.

When the refrigerant control valve 50 is closed, the refrigerant flow on the cold air passage L may be blocked, and the operation of the condenser 20 may be stopped. Accordingly, the control unit 60 may stop driving of the heat dissipation fan 80 for heat dissipation of the condenser 20.

Hereinafter, a method of controlling a refrigerant control valve of the present invention will be described in detail with reference to FIG. 7. The refrigerant control valve control method illustrated in FIG. 7 may be performed by the above-described controller 60.

The control unit 60 may continuously determine whether the inside temperature of the refrigerator satisfies the compressor driving condition (S11).

When the compressor driving condition is satisfied, the control unit 60 may drive the compressor (S12). Since the method of driving the compressor has been described above with reference to FIG. 3, a detailed description will be omitted here.

Subsequently, the control unit 60 determines whether a minimum delay time (see 't2-t1' in FIG. 5) has elapsed since the compressor was driven to exclude electrical disturbances occurring in the initial stage of driving of the compressor from the control parameters of the refrigerant control valve. It can be determined (S13).

After the minimum delay time has elapsed, the controller 60 may calculate the phase difference between the stroke of the piston in the compressor and the current applied to the linear motor in the compressor (S14).

Subsequently, the control unit 60 may determine whether the calculated amount of phase difference change has a positive sign (S15). As described with reference to FIG. 5, when the minimum delay time t2-t1 elapses after the compressor is driven, the phase difference decreases until the discharge valve is opened and then increases when the discharge valve is opened.

The control unit 60 may determine whether the amount of change in the phase difference has a positive sign, and identify an inflection point at which the sign of the amount of change in the phase difference is inverted from a negative sign to a positive sign.

If it is determined that the amount of change in the eddy phase has a positive sign, the control unit 60 may open the refrigerant control valve and drive the heat dissipation fan (S16).

Subsequently, the control unit 60 continuously determines whether the inside temperature of the compressor satisfies the compressor operation stop condition (S17), and when the compressor operation stop condition is satisfied, the refrigerant control valve may be closed and the heat dissipation fan may be stopped ( S18).

The above-described invention, the above-described embodiments and the accompanying drawings because it is possible for a person having ordinary skill in the art to which the present invention pertains, various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It is not limited by.

Claims (12)

A compressor that compresses the refrigerant through driving the linear motor;
A condenser condensing the refrigerant compressed in the compressor;
An expansion mechanism that expands the refrigerant condensed in the condenser under reduced pressure;
An evaporator that evaporates the refrigerant expanded in the expansion mechanism to generate cold air;
A refrigerant control valve provided on a cold air flow path through which the refrigerant flows to regulate the flow of the refrigerant; And
And a control unit that calculates a phase difference between a stroke of a piston reciprocating in the compressor by the linear motor and a motor current applied to the linear motor, and controls the refrigerant control valve based on the amount of change in the phase difference.
Refrigerator.
According to claim 1,
The compressor
A cylinder forming a compression space of the refrigerant;
The piston reciprocating inside the cylinder,
The linear motor for providing a driving force to the piston,
It includes a discharge valve for discharging the refrigerant compressed in the compression space
Refrigerator.
According to claim 2,
The discharge valve
A refrigerator that opens when the pressure formed in the compression space is greater than or equal to a preset pressure.
According to claim 1,
The control unit
A refrigerator that calculates the stroke of the piston based on the motor voltage and motor current applied to the linear motor.
According to claim 4,
The control unit
A refrigerator that calculates the phase difference by comparing the phase value of the calculated stroke with the phase value of the motor current.
According to claim 1,
The control unit
A refrigerator for calculating the amount of change in phase difference based on the first phase difference calculated at the first time point and the second phase difference calculated at the second time point after the reference time from the first time point.
According to claim 1,
The control unit
The refrigerator calculates the amount of change in the phase difference after a preset time from the start time of driving the compressor.
According to claim 1,
The control unit
A refrigerator that identifies a point of inflection of the phase difference based on the amount of change in the phase difference, and controls the refrigerant control valve at the identified inflection point.
The method of claim 8,
The control unit
A refrigerator that identifies a point in time when the amount of change in the phase difference changes from negative to positive as the point of inflection.
The method of claim 9,
The control unit
A refrigerator that opens the refrigerant control valve at the inflection point of the phase difference.
According to claim 1,
The control unit
A refrigerator that closes the refrigerant control valve when the driving stop condition of the compressor is satisfied.
According to claim 1,
The control unit
A refrigerator that drives a heat dissipation fan that introduces air to the condenser while opening the refrigerant control valve, and stops operation of the heat dissipation fan while closing the refrigerant control valve.

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