KR20130101258A - Heat pump system for vehicle and its control method - Google Patents

Abstract

PURPOSE: A heat pump system for vehicles and a control method thereof are provided to control the defrosting of the system by using the refrigerant pressure in an entrance of an outdoor heat exchanger and differences of outdoor temperature of the vehicle and the refrigerant temperature in an exit and detecting the frosting of the outdoor heat exchanger. CONSTITUTION: A heat pump system for vehicles comprises a first bypass line (R1) and a control unit. The first bypass line connects a refrigerant circulation line (R) in an entrance of a first expansion unit (140) and a refrigerant circulation line in an exit of an evaporator (160). The first bypass line makes a refrigerant circulating the refrigerant circulation line selectively bypass the first expansion unit and the evaporator. The control unit controls the system as it is determined to generate the defrost in an outdoor heat exchanger (130) when the difference value of outdoor temperatures of the vehicle and refrigerant temperatures in an exit of the outdoor heat exchanger is greater than a predetermined temperature and the refrigerant pressure of an entrance of the outdoor heat exchanger is lower than a reference value in a heat pump mode.

Description

Heat pump system for vehicle and its control method

The present invention relates to a vehicle heat pump system and a control method thereof, and more particularly, in a heat pump mode, a difference between a vehicle outside temperature and a refrigerant temperature of an outlet side of an outdoor heat exchanger is a predetermined temperature or more, and an inlet side of an outdoor heat exchanger. The present invention relates to a vehicle heat pump system and a method of controlling the same, wherein when the refrigerant pressure is equal to or less than a reference value, it is determined that an frost has occurred in the outdoor heat exchanger, and the system is defrosted.

Background Art [0002] A vehicle air conditioner generally includes a cooling system for cooling the interior of a vehicle and a heating system for heating the interior of the vehicle. Wherein the cooling system is configured to cool air in the vehicle interior by exchanging air passing through the outside of the evaporator at the evaporator side of the refrigerant cycle with the refrigerant flowing in the evaporator to convert into cool air, The air passing through the outside of the core is exchanged with the cooling water flowing in the inside of the heater core to warm the inside of the vehicle.

A heat pump system which can selectively perform cooling and heating by switching the flow direction of refrigerant by using one refrigerant cycle is different from the above vehicle air conditioning system. For example, two heat exchangers (That is, an indoor heat exchanger installed inside the air conditioner case for exchanging heat with air blown into the vehicle interior, and an outdoor heat exchanger for exchanging heat outside the air conditioner case), and a direction control valve for switching the flow direction of the refrigerant do. Therefore, when the cooling mode is operated according to the flow direction of the refrigerant by the direction control valve, the indoor heat exchanger functions as a cooling heat exchanger. When the heating mode is activated, the indoor heat exchanger functions as a heating heat exchanger .

Various kinds of such a heat pump system for vehicles have been proposed, and a representative example thereof is shown in Fig.

1 includes a compressor 30 for compressing and discharging a refrigerant, a high-pressure side heat exchanger 32 for dissipating the refrigerant discharged from the compressor 30, A first expansion valve 34 and a first bypass valve 36 for selectively passing the refrigerant passed through the high pressure side heat exchanger 32 and a second expansion valve 34 and a first bypass valve 36 Pressure side heat exchanger (60) for evaporating the refrigerant that has passed through the outdoor heat exchanger (48), and a low-pressure side heat exchanger (60) for evaporating the refrigerant that has passed through the outdoor heat exchanger An accumulator 62 for separating the refrigerant having passed through it into a gas phase and a liquid phase refrigerant, an internal heat exchanger 50 for exchanging heat between the refrigerant supplied to the low pressure side heat exchanger 60 and the refrigerant returning to the compressor 30, Pressure side heat exchanger (60), and a low-pressure side heat exchanger The second expansion valve 56 and the second expansion valve 56 are provided in parallel with each other so as to selectively connect the outlet side of the outdoor heat exchanger 48 and the inlet side of the accumulator 62, 2 bypass valve (58).

1, reference numeral 10 denotes an air conditioning case in which the high-pressure side heat exchanger 32 and the low-pressure side heat exchanger 60 are incorporated, reference numeral 12 denotes a temperature control door for controlling the mixing amount of cold air and warm air, And an air blower installed at the entrance of the air conditioning case.

The first bypass valve 36 and the second expansion valve 56 are closed and the first expansion valve (heating mode) 34 and the second bypass valve 58 are opened. In addition, the temperature control door 12 operates as shown in Fig. Therefore, the refrigerant discharged from the compressor 30 flows through the high-pressure side heat exchanger 32, the first expansion valve 34, the outdoor heat exchanger 48, the high-pressure portion 52 of the internal heat exchanger 50, The accumulator 62 and the low pressure section 54 of the internal heat exchanger 50 in this order. That is, the high-pressure side heat exchanger 32 serves as a radiator and the outdoor heat exchanger 48 serves as an evaporator.

When the air conditioning mode (cooling mode) is activated, the first bypass valve 36 and the second expansion valve 56 are opened, and the first expansion valve 34 and the second bypass valve 58 are closed do. Further, the temperature control door 12 closes the high-pressure side heat exchanger 32 passage. Therefore, the refrigerant discharged from the compressor 30 flows through the high-pressure side heat exchanger 32, the first bypass valve 36, the outdoor heat exchanger 48, the high-pressure portion 52 of the internal heat exchanger 50, The low pressure side heat exchanger 60, the accumulator 62 and the low pressure portion 54 of the internal heat exchanger 50 in this order. That is, the low-pressure side heat exchanger 60 serves as an evaporator, and the high-pressure side heat exchanger 32 closed by the temperature control door 12 serves as a radiator as in the heat pump mode do.

However, in the conventional vehicle heat pump system, the high pressure side heat exchanger 32 installed inside the air conditioning case 10 serves as a heater in the heat pump mode (heating mode) to perform heating, and the outdoor heat exchange The air 48 is installed outside the air conditioning case 10, that is, the engine room front side of the vehicle, and serves as an evaporator that exchanges heat with outside air.

At this time, the surface of the outdoor heat exchanger 48 drops below the freezing point while the temperature of the refrigerant flowing into the outdoor heat exchanger 48 is exchanged with the outside air, and thus, the surface of the outdoor heat exchanger 48 begins to be implanted. do.

When the frost is continuously enlarged on the surface of the outdoor heat exchanger 48, the outdoor heat exchanger 48 does not endotherm, so that the temperature and pressure of the refrigerant in the system are lowered and the temperature of the air discharged into the cabin is lowered, thereby heating performance. This markedly reduced, there was a problem that the liquid refrigerant can be introduced into the compressor and the stability of the system is also reduced.

An object of the present invention for solving the above problems is, in the heat pump mode, when the difference between the vehicle outside temperature and the outlet refrigerant temperature of the outdoor heat exchanger is a predetermined temperature or more, and the inlet refrigerant pressure of the outdoor heat exchanger is less than the reference value, Determination control of the system by determining that the outdoor heat exchanger has occurred is carried out to detect defrosting of the outdoor heat exchanger in a timely manner, thereby achieving defrosting control and defrosting effect. Thus, heating performance and An object of the present invention is to provide a vehicle heat pump system and a method of controlling the same, which can improve stability.

The present invention for achieving the above object is, respectively installed on the refrigerant circulation line, the compressor for compressing and discharging the refrigerant, and installed inside the air conditioning case heat exchange between the air in the air conditioning case and the refrigerant discharged from the compressor A heat exchanger installed inside the air conditioning case to exchange heat between the air in the air conditioning case and the refrigerant supplied to the compressor, and a heat exchanger installed outside the air conditioning case to circulate the refrigerant circulation line. First expansion means installed on an outdoor heat exchanger and an inlet refrigerant circulation line of the evaporator to expand the refrigerant, and second expansion means installed on a refrigerant circulation line between the indoor heat exchanger and the outdoor heat exchanger to expand the refrigerant; In the vehicle heat pump system comprising a, inlet refrigerant circulation of the first expansion means A first bypass line configured to connect phosphorus to a refrigerant circulation line at the outlet side of the evaporator so that refrigerant circulating in the refrigerant circulation line selectively bypasses the first expansion means and the evaporator, and in a heat pump mode, the vehicle A control unit for defrosting the system by determining that an frost has occurred in the outdoor heat exchanger when the difference between the outside temperature and the outlet refrigerant temperature of the outdoor heat exchanger is equal to or greater than a predetermined temperature and the inlet refrigerant pressure of the outdoor heat exchanger is equal to or less than a reference value. Characterized in that comprises a.

In the control method of the vehicle heat pump system, the first step of determining whether the system is in the heat pump mode, and if the determination result of the first step, the heat pump mode, the vehicle outside temperature and the refrigerant at the outlet of the outdoor heat exchanger A second step of determining whether the temperature difference is greater than or equal to a predetermined temperature, a third step of determining whether or not the refrigerant pressure of the inlet side of the outdoor heat exchanger is equal to or less than a reference value when the determination result of the second step is greater than or equal to a predetermined temperature; As a result of the determination in the third step, if it is less than the reference value, it characterized in that it comprises a fourth step of determining that the frost has occurred in the outdoor heat exchanger and defrost control of the system.

In the heat pump mode, when the difference between the vehicle outside temperature and the outlet refrigerant temperature of the outdoor heat exchanger is greater than or equal to a predetermined temperature (10 ° C.) and the inlet refrigerant pressure of the outdoor heat exchanger is equal to or less than the reference value, the outdoor heat exchanger is implanted into the outdoor heat exchanger. Determination control of the outdoor heat exchanger by determining that this has occurred, and thus the defrosting control and defrosting effect can be obtained by performing the defrost control by timely recognizing the frost of the outdoor heat exchanger, thereby improving the heating performance and stability of the system. Can be.

1 is a schematic view showing a conventional heat pump system for a vehicle,
FIG. 2 is a diagram showing an air conditioner mode in a heat pump system for a vehicle according to the present invention,
3 is a view showing a first heating mode of a heat pump mode in a vehicle heat pump system according to the present invention;
4 is a view showing a dehumidifying mode during a first heating mode operation of a heat pump mode in a vehicle heat pump system according to the present invention;
5 is a view showing a second heating mode of the heat pump mode in the vehicle heat pump system according to the present invention;
6 is a view showing a dehumidifying mode during the second heating mode operation of the heat pump mode in the vehicle heat pump system according to the present invention;
7 shows the outdoor heat exchanger inlet / outlet side refrigerant temperature, the compressor outlet side refrigerant pressure and temperature, and the outside air temperature-outdoor heat exchanger outlet side refrigerant temperature when the outside air temperature is 0 ° C. in the vehicle heat pump system according to the present invention. graph,
8 is a flowchart illustrating a control method of a vehicle heat pump system according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the vehicle heat pump system according to the present invention, the compressor 100, the indoor heat exchanger 110, the second expansion means 120, the outdoor heat exchanger 130 and the refrigerant circulation line (R) The first expansion means 140 and the evaporator 160 are sequentially connected to each other, and are preferably applied to an electric vehicle or a hybrid vehicle.

In addition, on the refrigerant circulation line R, the first bypass line R1 bypasses the first expansion means 140 and the evaporator 160 and the second bypass bypasses the outdoor heat exchanger 130. A line R2 and an expansion line R3 on which the second expansion means 120 are installed are connected in parallel, respectively, and a first direction switching valve 191 is formed at a branch point of the first bypass line R1. Is installed, a second diverter valve 192 is installed at a branch point of the second bypass line R2, and a third diverter valve 193 is installed at a branch point of the expansion line R3. do.

In addition, a branch line (R4) is provided to connect the outlet refrigerant circulation line (R) and the first bypass line (R1) of the first expansion means 140, on and off on the branch line (R4). The valve 195 is installed.

Therefore, in the air conditioner mode, the refrigerant discharged from the compressor 100 as shown in Figure 2 is the indoor heat exchanger 110, the outdoor heat exchanger 130, the first expansion means 140, the evaporator 160, the compressor ( 100 is sequentially circulated, wherein the indoor heat exchanger 110 serves as a condenser and the evaporator 160 serves as an evaporator.

Meanwhile, the outdoor heat exchanger 130 functions as a condenser as the indoor heat exchanger 110.

In the heat pump mode (first heating mode), the refrigerant discharged from the compressor 100 as shown in Figure 3 is the indoor heat exchanger 110, the second expansion means 120, the outdoor heat exchanger 130, 1 bypass line (R1), the compressor 100 is sequentially circulated, wherein the indoor heat exchanger 110 serves as a condenser and the outdoor heat exchanger 130 serves as an evaporator, One expansion means 140 and the evaporator 160 is not supplied to the refrigerant.

As described above, the heat pump system of the present invention can share the refrigerant circulation line R with the same refrigerant circulation direction in the air conditioner mode and the heat pump mode, prevents the refrigerant stagnation phenomenon that occurs when the refrigerant does not flow, The circulation line (R) can also be simplified.

In the present invention, the heat pump mode is diversified as in the first heating mode, the second heating mode, and the dehumidification mode, and in the heat pump mode, in the occurrence of the frosting of the outdoor heat exchanger 130, the following will be described later. Defrost control is performed through a controller (not shown).

The controller may perform the first heating mode in the heat pump mode when the outside temperature is higher than the reference temperature, and perform the second heating mode in the heat pump mode when the outside temperature is less than the reference temperature.

Here, if the outside temperature is 0 ° C. or more (image), the first heating mode is performed. If the outside temperature is less than 0 ° C. (zero), the second heating mode is performed.

Of course, the reference temperature of the outside temperature for distinguishing the first and second heating modes is not limited to 0 ° C., and may be changed according to the purpose.

In addition, the dehumidification mode is performed when the interior of the vehicle is dehumidified in the first and second heating modes.

Hereinafter, each component of the heat pump system will be described in detail.

First, the compressor 100 installed on the refrigerant circulation line R receives power from an engine (an internal combustion engine, a motor, or the like), sucks the refrigerant, compresses the refrigerant, and discharges the compressed refrigerant in a gas state of high temperature and high pressure.

The compressor 100 sucks and compresses the refrigerant discharged from the evaporator 160 in the air conditioning mode and supplies the compressed refrigerant to the indoor heat exchanger 110. In the heat pump mode, The refrigerant having passed through the first bypass line R1 is sucked, compressed, and supplied to the indoor heat exchanger 110 side.

In the dehumidifying mode of the heat pump mode, since the refrigerant is simultaneously supplied to the first bypass line (R1) and the evaporator (160) through the branch line (R4) described later, the compressor (100) 1 bypass line R1 and the evaporator 160, sucks the combined refrigerant, compresses it, and supplies it to the indoor heat exchanger 110 side.

The indoor heat exchanger 110 is installed inside the air conditioning case 150 and is connected to the refrigerant circulation line R at the outlet side of the compressor 100 and is connected to the air flowing in the air conditioning case 150 The refrigerant discharged from the compressor 100 is heat-exchanged.

The evaporator 160 is installed inside the air conditioning case 150 and is connected to the refrigerant circulation line R at the inlet side of the compressor 100 so that the air flowing in the air conditioning case 150 And the refrigerant supplied to the compressor 100 is heat-exchanged.

The indoor heat exchanger 110 functions as a condenser in both the air conditioning mode and the heat pump mode,

The evaporator 160 serves as an evaporator in the air conditioning mode, and stops operating because the refrigerant can not be supplied during the first and second heating modes of the heat pump mode. In the dehumidifying mode, a part of the refrigerant is supplied to serve as an evaporator do.

At this time, the performance of the evaporator 160 in the dehumidification mode is lower than the evaporator performance of the evaporator 160 in the air conditioner mode.

The indoor heat exchanger 110 and the evaporator 160 are installed in the air conditioner case 150 at a predetermined distance from the air conditioner case 150, And an indoor heat exchanger 110 are sequentially installed.

Therefore, in the air conditioner mode in which the evaporator 160 serves as an evaporator, as shown in FIG. 2, a low temperature low pressure refrigerant discharged from the first expansion means 140 is supplied to the evaporator 160, and at this time, a blower ( The air flowing through the inside of the air conditioning case 150 through the evaporator 160 is exchanged with the low temperature low pressure refrigerant inside the evaporator 160 to be converted into cold air, and then discharged into the vehicle interior. The interior of the car is cooled.

3, the high-temperature and high-pressure refrigerant discharged from the compressor 100 is supplied to the indoor heat exchanger 110 and the refrigerant discharged from the outdoor heat exchanger 110 to the indoor heat exchanger 110. In the heat pump mode (first heating mode) in which the indoor heat exchanger 110 functions as a condenser, The air flowing inside the air conditioning case 150 through the blower (not shown) flows through the indoor heat exchanger 110, and the refrigerant in the indoor heat exchanger 110 is heat- And then it is discharged to the inside of the vehicle to heat the inside of the vehicle.

The size of the evaporator 160 may be larger than the size of the indoor heat exchanger 110.

The amount of air passing through the indoor heat exchanger 110 and the amount of air passing through the indoor heat exchanger 110 are adjusted between the evaporator 160 and the indoor heat exchanger 110 in the air conditioning case 150 A temperature control door 151 is provided.

The temperature control door 151 adjusts the amount of air passing through the indoor heat exchanger 110 and the amount of air passing through the indoor heat exchanger 110 to control the temperature of the air discharged from the air conditioning case 150 Can be adjusted appropriately,

2, when the front side passageway of the indoor heat exchanger 110 is completely closed through the temperature control door 151 as shown in FIG. 2, the cold air passing through the evaporator 160 passes through the indoor heat exchanger 110, The indoor heat exchanger 110 is bypassed through the temperature control door 151 as shown in FIG. 3 during the heat pump mode (in the first heating mode) All the air passes through the indoor heat exchanger 110 serving as a condenser and is converted into warm air, and the warm air is supplied to the interior of the vehicle, so that the maximum heating is performed.

The outdoor heat exchanger 130 is installed outside the air conditioning case 150 and is connected to the refrigerant circulation line R to exchange heat between the refrigerant circulating in the refrigerant circulation line R and the outside air do.

The outdoor heat exchanger 130 is installed on the front side of the vehicle engine room to exchange heat with refrigerant flowing in the outdoor space.

The outdoor heat exchanger 130 functions as the same condenser as the indoor heat exchanger 110 in the air conditioning mode. At this time, the high-temperature refrigerant flowing in the outdoor heat exchanger 130 is condensed while exchanging heat with the outside air . In the heat pump mode (first heating mode), the refrigerant acts as an evaporator opposite to the indoor heat exchanger 110. At this time, the low-temperature refrigerant flowing in the outdoor heat exchanger 130 is evaporated as heat is exchanged with the outside air do.

In addition, the first expansion means 140 is installed on the inlet refrigerant circulation line R of the evaporator 160 to expand the refrigerant supplied to the evaporator 160.

That is, the first expansion means 140 expands the refrigerant discharged from the outdoor heat exchanger 130 in the air conditioner mode so as to be in a liquid phase (wet-saturated) state at low temperature and low pressure, and then supplies it to the evaporator 160. Done.

The first expansion means 140 is preferably made of an expansion valve, but may be made of an orifice.

In addition, the second expansion means 120 is installed on the refrigerant circulation line R between the indoor heat exchanger 110 and the outdoor heat exchanger 130, and performs the outdoor heat exchange according to the air conditioner mode or the heat pump mode. The refrigerant supplied to the unit 130 is selectively expanded.

The second expansion means 120 is installed on an expansion line R3 connected in parallel on the refrigerant circulation line R between the indoor heat exchanger 110 and the outdoor heat exchanger 130.

Here, the second expansion means 120 is preferably made of an orifice 121, but may be made of an expansion valve.

In addition, at the branch point of the expansion line (R3) and the refrigerant circulation line (R), the refrigerant passing through the indoor heat exchanger (110) in accordance with the air conditioning mode or the heat pump mode through the expansion line (R3) a second A third direction switching valve 193 is installed to change the refrigerant flow direction so as to pass through the expansion means 120 or bypass the second expansion means 120.

Therefore, in the air conditioner mode, the refrigerant discharged from the compressor 100 by the third direction switching valve 193 and passed through the indoor heat exchanger 110 bypasses the second expansion means 120. It is supplied to the outdoor heat exchanger 130, and in the heat pump mode (in the first heating mode), is discharged from the compressor (100) by the third direction switching valve (193) to the indoor heat exchanger (110) The refrigerant passing through is expanded while passing through the expansion line R3 and the second expansion means 120, and then is supplied to the outdoor heat exchanger 130.

The first bypass line R1 is installed to connect the inlet refrigerant circulation line R of the first expansion means 140 and the outlet refrigerant circulation line R of the evaporator 160. The refrigerant circulating in the refrigerant circulation line R selectively bypasses the first expansion means 140 and the evaporator 160.

As shown in the drawing, the first bypass line R1 is disposed in parallel with the first expansion means 140 and the evaporator 160, that is, the inlet side of the first bypass line R1 is located outdoors. It is connected to the refrigerant circulation line (R) for connecting the heat exchanger 130 and the first expansion means 140, the outlet side is connected to the refrigerant circulation line (R) for connecting the evaporator (160) and the compressor (100). .

Thus, in the air conditioner mode, the refrigerant passing through the outdoor heat exchanger 130 flows to the first expansion means 140 and the evaporator 160, but in the heat pump mode (in the first heating mode), The refrigerant passing through the outdoor heat exchanger 130 flows directly to the compressor 100 through the first bypass line R1 to bypass the first expansion means 140 and the evaporator 160.

Here, the function of switching the flow direction of the refrigerant according to the air conditioner mode and the heat pump mode is performed through the first direction switching valve 191.

The first direction switching valve 191 is installed at the branch point of the first bypass line (R1) and the refrigerant circulation line (R), the outdoor heat exchanger 130 according to the air conditioner mode or the heat pump mode Refrigerant passing through the refrigerant flow direction is changed so as to flow to the first bypass line (R1) or the first expansion means (140).

At this time, the first direction switching valve 191, the refrigerant discharged from the compressor 100 in the air conditioner mode and passed through the indoor heat exchanger 110 and the outdoor heat exchanger 130 is the first expansion means 140 and The direction is changed to flow to the evaporator 160 side, and discharged from the compressor 100 in the heat pump mode (in the first heating mode), the indoor heat exchanger 110 and the second expansion means 120 and the outdoor heat exchanger. The refrigerant is passed through the 130 to change the direction to flow to the first bypass line (R1).

Meanwhile, the first directional control valve 191 is provided at a branch point on the inlet side of the first bypass line R1, and it is preferable to use a three-way valve.

It is preferable that not only the first direction switching valve 191 but also the second direction switching valve 192 and the third direction switching valve 193 use a three-way valve.

In addition, a second bypass line R2 is installed in parallel in the refrigerant circulation line R such that the refrigerant selectively passing through the second expansion means 120 bypasses the outdoor heat exchanger 130. That is, the second bypass line R2 is installed to connect the inlet and outlet side refrigerant circulation lines R of the outdoor heat exchanger 130 so that the refrigerant circulating through the refrigerant circulation line R is the outdoor heat exchanger. Bypass (130).

In addition, at a branch point between the second bypass line R2 and the refrigerant circulation line R, the refrigerant flows to the outdoor heat exchanger 130 or the second bypass line R2 according to the outside air temperature. The second direction switching valve 192 for switching the flow direction is installed.

At this time, when the outside temperature is an image, the refrigerant is controlled to flow to the outdoor heat exchanger 130 through the control of the second direction switching valve 192, and when the outside temperature is below zero, the second direction switching valve Through the control of 192, the refrigerant is controlled to bypass the outdoor heat exchanger 130 and flow toward the second bypass line R2.

In other words, in a low heat source condition where the outside air temperature is below zero, as shown in the second heating mode of FIG. 5, the refrigerant that has passed through the second expansion means 120 is transferred to the outdoor heat exchanger to minimize the influence of low temperature outside air. Bypass 130 to flow to the second bypass line (R2) side.

An electric heater 115 is further installed on the downstream side of the indoor heat exchanger 110 in the air conditioning case 150 to improve the heating performance.

That is, the heating performance can be improved by operating the electric heating type heater 115 as an auxiliary heat source at the start of the vehicle, and the electric heating type heater 115 can be operated even when the heating heat source is insufficient.

As the electric heater 115, a PTC heater is preferably used.

On the first bypass line R1, a heat supply means 180 for supplying heat to the refrigerant flowing along the first bypass line R1 is installed.

The heat supply unit 180 is a refrigerant heat exchanger through which the refrigerant flowing through the first bypass line R1 flows to supply the waste heat of the vehicle electronics 200 to the refrigerant flowing through the first bypass line R1. A water-cooled heat exchanger 181 including a portion 181a and a coolant heat exchanger 181b provided at one side of the refrigerant heat exchanger 181a and having a coolant circulating in the vehicle electrical equipment 200 flows therethrough. It is done by

Therefore, the heating performance can be improved by recovering the heat source from the waste heat of the vehicle electrical equipment 200 in the heat pump mode.

On the other hand, the vehicle electrical equipment 200 is typically a motor, an inverter, or the like.

The inlet side first bypass line (R1) of the heat supply means (180) is connected to the evaporator (160) to supply a part of the refrigerant flowing toward the heat supply means (180) along the first bypass line (R1) Off valve 195 is provided on the branch line R4 for controlling the flow of the refrigerant on / off, and a branch line R4 for connecting the inlet side refrigerant circulation line R of the evaporator 160 .

The on-off valve 195 is opened in the dehumidification mode, so that some of the refrigerant flowing to the first bypass line R1 by the first direction switching valve 191 passes through the water-cooled heat exchanger 181, and the vehicle electrical equipment. The waste heat of the 200 is recovered, and a part of the waste heat passes through the evaporator 160 through the branch line R4.

Accordingly, the air flowing inside the air conditioning case 150 is dehumidified while passing through the evaporator 160, that is, during the heat pump mode operation such as the first and second heating modes, the branch line R4 ) Can perform dehumidification in the car interior.

Meanwhile, in the second heating mode and the dehumidifying mode among the second heating modes operating under the condition of the outside temperature, the air inflow mode of the air conditioning case 150 can recover the heat source of the indoor air to improve heating performance. It is preferable to operate the bet inflow mode so that the bet is introduced into the air conditioning case 150.

An accumulator 170 is installed on the refrigerant circulation line R on the inlet side of the compressor 100.

The accumulator 170 separates the liquid refrigerant and the gaseous refrigerant from the refrigerant supplied to the compressor 100 so that only the gaseous refrigerant can be supplied to the compressor 100.

In addition, a control unit (not shown) is provided to control the heat pump system of the present invention. In the heat pump mode, the control unit may have a difference between a vehicle outside temperature and a refrigerant temperature at the outlet side of the outdoor heat exchanger 130 by a predetermined temperature or more. When the inlet refrigerant pressure of the outdoor heat exchanger 130 is equal to or less than a reference value, it is determined that an frost has occurred in the outdoor heat exchanger 130, and the defrosting control (defrost mode) of the system is performed.

At this time, the control unit, if the difference between the outside temperature of the vehicle and the refrigerant temperature of the outlet side of the outdoor heat exchanger 130 is 10 ℃ or more and the inlet refrigerant pressure of the outdoor heat exchanger 130 is less than the reference value, the outdoor heat exchange It is determined that the implantation has occurred in the device 130.

In other words, when the surface of the outdoor heat exchanger 130, which serves as the evaporator in the heat pump mode, falls below the freezing point, frosting starts to occur on the surface of the outdoor heat exchanger 130. At this time, the vehicle outdoor temperature and the outdoor heat exchanger When the difference in the refrigerant temperature of the outlet side of 130 is 10 ° C or more it will be recognized that the frosting occurred in the outdoor heat exchanger (130).

In addition, when the inlet-side refrigerant pressure of the outdoor heat exchanger 130 is determined to be equal to or less than a reference value, it is possible to determine the idea based on this. Although the inlet-side refrigerant pressure of the outdoor heat exchanger 130 is not shown in FIG. Since the pressure and the refrigerant temperature are closely related, the refrigerant pressure can be predicted by referring to the refrigerant temperature of the inlet side of the outdoor heat exchanger 130 shown in FIG. 7.

Of course, if the refrigerant temperature is less than the reference value by checking the refrigerant temperature instead of the inlet refrigerant pressure of the outdoor heat exchanger 130, it may be determined based on this.

7 is a graph showing the outdoor heat exchanger inlet / outlet side refrigerant temperature, the compressor discharge port side refrigerant pressure and temperature, and the outside air temperature to the outdoor heat exchanger outlet side refrigerant temperature when the outside air temperature is 0 ° C.

As can be seen, when the electric field waste heat (electric equipment waste heat) and the bet 20% are supplied to the heat source of the system, a sufficient heat source is supplied to the system, so that no idea is generated in the outdoor heat exchanger 130.

In the case where the electric field waste heat and the bet is 0%, even though the bet is 0%, the electric field waste heat is supplied so that no frosting occurs in the outdoor heat exchanger 130. Of course, in this case it can be seen that the heating pressure of the system is also reduced by reducing the refrigerant pressure and temperature of the discharge port side of the compressor 100 than when the bet is supplied 20%.

Subsequently, when the electrical waste heat is shut off, the pressure and temperature of the refrigerant at the discharge port side of the compressor 100 are further reduced, and the difference between the outside temperature of the vehicle and the refrigerant temperature at the outlet side of the outdoor heat exchanger 130 gradually increases And concealment starts on the surface of the outdoor heat exchanger (130).

At this time, if no additional heat source is supplied to the system after the occurrence of the frost on the surface of the outdoor heat exchanger 130, that is, if the defrost control is not performed, the frost is continuously enlarged so that the outdoor heat exchanger 130 does not endotherm. As a result, the refrigerant temperature and pressure in the system are lowered, thereby lowering the temperature of the air discharged into the room, thereby lowering the heating performance, as well as introducing the liquid refrigerant into the compressor 100, thereby reducing the stability of the system.

Referring to FIG. 7, after the electric field waste heat is blocked to start implantation on the surface of the outdoor heat exchanger 130, the difference between the vehicle outside air temperature and the refrigerant temperature at the outlet side of the outdoor heat exchanger 130 is 10 ° C. FIG. As described above, when the inlet refrigerant pressure of the outdoor heat exchanger 130 is equal to or less than the reference value, the control unit determines that an frost has occurred in the outdoor heat exchanger 130, and defrosts the system.

Referring to FIG. 7, after the start of implantation in the outdoor heat exchanger 130, the control unit recognizes the implantation, and then supplies 30% of the bet as part of the defrosting control. It can be seen that the heating performance is also increased as the temperature rises. However, since the difference between the outside temperature of the vehicle and the refrigerant temperature of the outlet side of the outdoor heat exchanger 130 is 10 ° C. or more, the controller applies electric field waste heat to perform defrost control.

When defrosting control is performed by applying the electric field waste heat, the refrigerant pressure and temperature of the discharge port side of the compressor 100 increase rapidly, and the temperature of the refrigerant flowing into the outdoor heat exchanger 130 also increases, thereby increasing the temperature of the outdoor heat exchanger. Defrost of 130 is to begin. At this time, the difference between the outside temperature of the vehicle and the outlet side refrigerant temperature of the outdoor heat exchanger 130 decreases gradually to less than 10 ° C.

As such, when the controller recognizes that the frost has occurred in the outdoor heat exchanger 130, the controller performs defrost control to increase the refrigerant pressure and temperature of the system through the defrost control, thereby heating the system and stability of the system. Will be improved.

On the other hand, as the defrosting control method through the control unit, as well as the method of applying the electric field waste heat, the refrigerant pressure of the system by reducing the refrigerant flow rate of the system by controlling the rotation speed (RPM) of the compressor (100) of the system and The temperature may be increased, or the refrigerant temperature of the system may be increased by supplying the air through the air inflow mode of the air conditioning case 150 and controlling the air volume to increase.

Of course, various methods for increasing the refrigerant pressure and temperature of the system as well as the above defrosting control method can be used.

In addition, the control unit may control to increase the capacity of the electric heating heater 115 when the heating heat source is insufficient during the defrosting control.

Hereinafter, the control method of the vehicular heat pump system will be described with reference to FIG.

First, a first step S1 of determining whether the system is a heat pump mode is performed.

The heat pump mode is a heating mode in which the outdoor heat exchanger 130 serves as an evaporator, and includes a first heating mode and a dehumidifying mode of the first heating mode.

As a result of the determination in the first step S1, if the heat pump mode, the second step (S2) of determining whether the difference between the vehicle outside temperature and the refrigerant temperature of the outlet side of the outdoor heat exchanger 130 is a predetermined temperature or more.

That is, in the second step (S2), it is a step of determining whether the difference between the vehicle outside temperature and the refrigerant temperature of the outlet side of the outdoor heat exchanger 130 is 10 ° C or more.

In other words, when the surface of the outdoor heat exchanger 130, which serves as the evaporator in the heat pump mode, falls below the freezing point, frosting starts to occur on the surface of the outdoor heat exchanger 130. At this time, the vehicle outdoor temperature and the outdoor heat exchanger When the difference in the refrigerant temperature of the outlet side of 130 is 10 ° C or more, it is determined that the frost is generated in the outdoor heat exchanger (130).

If the difference between the vehicle outdoor air temperature and the outlet refrigerant temperature of the outdoor heat exchanger 130 is not greater than 10 ° C. in the second step S2, the process returns to the first step S1.

Subsequently, as a result of the determination in the second step S2, when the difference between the vehicle outside air temperature and the exit refrigerant temperature of the outdoor heat exchanger 130 is a predetermined temperature, that is, 10 ° C. or more, the outdoor heat exchanger 130 may be The third step S3 of determining whether the inlet refrigerant pressure is equal to or lower than the reference value is performed.

In the third step (S3), if the pressure of the inlet side of the outdoor heat exchanger 130 is less than the reference value, it may be determined based on this. In FIG. 7, the inlet refrigerant of the outdoor heat exchanger 130 may be determined. Although the pressure is not shown, since the refrigerant pressure and the refrigerant temperature are closely related, the refrigerant pressure may be predicted by referring to the refrigerant temperature of the inlet side of the outdoor heat exchanger 130 shown in FIG. 7.

Of course, if the refrigerant temperature is less than the reference value by checking the refrigerant temperature instead of the inlet refrigerant pressure of the outdoor heat exchanger 130, it may be determined based on this.

If the inlet refrigerant pressure of the outdoor heat exchanger 130 is not lower than or equal to the reference value in the third step S3, the flow returns to the first step S1.

Subsequently, when the determination result of the third step S3 indicates that the inlet refrigerant pressure of the outdoor heat exchanger 130 is equal to or less than the reference value, it is determined that an frost has occurred in the outdoor heat exchanger 130 to defrost the system. Proceed to the fourth step (S4).

In the fourth step S4, the difference between the vehicle outside temperature and the refrigerant temperature of the outlet side of the outdoor heat exchanger 130 is 10 ° C. or more (second step), and the inlet refrigerant pressure of the outdoor heat exchanger 130 is the reference value. If it is less than or equal to (third stage), that is, when both of the second stage (S2) and the third stage (S3) are satisfied, it is determined that the frost is generated in the outdoor heat exchanger 130 and the defrost control is performed. .

At this time, during the defrost control in the fourth step, the system is controlled to increase the refrigerant pressure and temperature of the system. More preferably, the system is controlled to increase the inlet refrigerant pressure and temperature of the outdoor heat exchanger 130.

As the defrosting control, the system can be controlled by appropriately combining the electric field waste heat application, the supply of the internal air, the control of the rotation speed of the compressor 100, and the like. In addition to the above method, various methods are used to increase the refrigerant pressure and temperature of the system. Can be used.

On the other hand, after the fourth step (S4), it is determined whether the defrost of the outdoor heat exchanger 130 is completed, and if it is completed proceeds to the fifth step (S5) to return to the first step (S1). do.

If the defrost of the outdoor heat exchanger 130 is not completed in the fifth step S5, the process returns to the fourth step S4.

Hereinafter, the operation of the vehicle heat pump system according to the present invention will be described.

end. Air conditioning mode (cooling mode) (Fig. 2)

In the air conditioner mode (cooling mode), as shown in FIG. 2, the first bypass line R1 is closed through the first direction switching valve 191, and the second direction switching valve 192 is closed. The second bypass line R2 is also closed, and the third diverter valve 193 closes the expansion line R3.

The cooling water circulating through the electrical component 200 is not supplied to the water-cooled heat exchanger 181 of the heat supply unit 180.

On the other hand, at the time of maximum cooling, the temperature control door 151 in the air conditioning case 150 is operated to close the passage through the indoor heat exchanger 110, so that the air blown into the air conditioning case 150 by the blower Is cooled while passing through the evaporator (160), and is then supplied to the interior of the vehicle by bypassing the indoor heat exchanger (110), thereby cooling the interior of the vehicle.

Next, the refrigerant circulation process will be described.

The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 100 after being compressed is supplied to the indoor heat exchanger 110 installed in the air conditioning case 150.

The refrigerant supplied to the indoor heat exchanger 110 is supplied to the outdoor heat exchanger 130 without heat exchange with air because the temperature control door 151 closes the passage on the indoor heat exchanger 110 as shown in FIG. .

The refrigerant flowing into the outdoor heat exchanger 130 is condensed while exchanging heat with the outside air, thereby changing the gaseous refrigerant into the liquid refrigerant.

On the other hand, both the indoor heat exchanger 110 and the outdoor heat exchanger 130 is condenser dynamics, but the refrigerant is mainly condensed in the outdoor heat exchanger 130 that exchanges heat with the outside.

Subsequently, the refrigerant passing through the outdoor heat exchanger 130 is expanded under reduced pressure in the course of passing through the first expansion means 140 to become a liquid refrigerant having a low temperature and low pressure, and then flows into the evaporator 160.

The refrigerant flowing into the evaporator 160 is heat-exchanged with the air blown into the air conditioning case 150 through the blower to evaporate, and at the same time, the air is cooled by an endothermic effect due to the latent heat of evaporation of the refrigerant. And supplied to the vehicle interior to be cooled.

Then, the refrigerant discharged from the evaporator 160 flows into the compressor 100 and recycles the cycle as described above.

I. In the first heating mode (FIG. 3) of the heat pump mode,

The first heating mode of the heat pump mode is a mode that operates under the condition that the outside temperature is an image, and uses waste heat of the outside and the vehicle electrical appliance 200 as a heat source, as shown in FIG. 3, the first directional valve 191. The first bypass line R1 is opened through the first bypass line R1, and the refrigerant is not supplied to the first expansion means 140 and the evaporator 160.

In addition, the second bypass line R2 is closed through the second diverter valve 192, and the expansion line R3 is opened through the third diverter valve 193.

On the other hand, the cooling water heated by the vehicle electrical component 200 is supplied to the cooling water heat exchanger 181b of the water-cooled heat exchanger 181 serving as the heat supply means 180.

In the first heating mode, the temperature control door 151 in the air conditioning case 150 is operated to close the passage bypassing the indoor heat exchanger 110, and is blown into the air conditioning case 150 by the blower Air passes through the evaporator 160 (operation stop), passes through the indoor heat exchanger 110, and is converted into hot air to be supplied to the interior of the vehicle, thereby heating the interior of the vehicle.

Next, the refrigerant circulation process will be described.

The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 100 after being compressed is introduced into the indoor heat exchanger 110 installed inside the air conditioning case 150.

The high-temperature, high-pressure gaseous refrigerant introduced into the indoor heat exchanger 110 is condensed while exchanging heat with the air blown into the air conditioning case 150 through the blower. At this time, air passing through the indoor heat exchanger 110 After changing to hot air, it is supplied to the interior of the vehicle, and the interior of the vehicle is heated.

Subsequently, the refrigerant discharged from the indoor heat exchanger 110 flows to the expansion line R3 through the third direction switching valve 193, and the refrigerant flowing to the expansion line R3 is the second refrigerant. In the process of passing through the expansion means 120 is expanded under reduced pressure to become a low-temperature low-pressure liquid refrigerant, it is supplied to the outdoor heat exchanger 130 that serves as an evaporator.

The refrigerant supplied to the outdoor heat exchanger 130 passes through a first bypass line R1 by the first direction switching valve 191 after evaporating while exchanging heat with the outside air, wherein the first bypass The refrigerant passing through the line R1 exchanges heat with the cooling water passing through the cooling water heat exchanger 181b in the course of passing through the refrigerant heat exchanger 181a of the water-cooled heat exchanger 181 to thereby remove waste heat of the vehicle electrical equipment 200. After recovery, the cycle as described above is recycled while flowing into the compressor 100.

If the difference between the vehicle outdoor air temperature and the outlet refrigerant temperature of the outdoor heat exchanger 130 is 10 ° C. or more and the inlet refrigerant pressure of the outdoor heat exchanger 130 is equal to or less than a reference value during the first heating mode operation, the control unit It is determined that the frost has occurred in the outdoor heat exchanger 130 to perform a defrost mode for defrosting the system.

In the defrost mode, the control of raising the refrigerant pressure and temperature of the system, such as applying the electric field waste heat, supplying the air to the air conditioning case 150, and controlling the rotation speed of the compressor 100, is performed.

All. In the first heating mode of the heat pump mode (Fig. 4)

The dehumidification mode during the first heating mode operation of the heat pump mode is activated when the room dehumidification is required during operation in the first heating mode of FIG.

Therefore, only the portions different from the first heating mode of FIG. 3 will be described.

During the dehumidification mode, the branch line R4 is further opened through the on-off valve 195 in the first heating mode.

In the dehumidifying mode, the temperature control door 151 in the air conditioning case 150 is operated to close the passage bypassing the indoor heat exchanger 110, so that the air blown into the air conditioning case 150 by the blower After passing through the evaporator 160, the refrigerant passes through the indoor heat exchanger 110 and is converted into hot air to be supplied to the interior of the vehicle, thereby heating the interior of the vehicle.

At this time, since the amount of the refrigerant supplied to the evaporator 160 is small, the air cooling performance is low, so that the change in the room temperature is minimized, and the air passing through the evaporator 160 is dehumidified smoothly.

Next, the refrigerant circulation process will be described.

The refrigerant passing through the compressor 100, the indoor heat exchanger 110, the second expansion means 120, and the outdoor heat exchanger 130 is transferred to the first bypass line R1 by the first direction switching valve 191. In this case, some of the refrigerant passing through the first bypass line (R1) passes through the refrigerant heat exchanger (181a) of the water-cooled heat exchanger (181). Heat exchange with the passing coolant to recover the waste heat of the vehicle electrical equipment 200 is evaporated, a part is supplied to the evaporator 160 through the branch line (R4) to exchange heat with the air flowing in the air conditioning case 150 It will evaporate in the process.

In this process, the air passing through the evaporator 160 is dehumidified, and the dehumidified air passing through the evaporator 160 is converted into hot air while passing through the indoor heat exchanger 110, Dehumidification is heated.

Then, the refrigerant having passed through the water-cooled heat exchanger 181 and the evaporator 160 is combined and then flows into the compressor 100, and recycles the cycle as described above.

la. In the second heating mode of the heat pump mode (Fig. 5)

The second heating mode of the heat pump mode is a mode in which the outdoor air is operated under the condition of zero temperature and uses waste heat of the indoor air (pump inflow mode) and the vehicle electrical appliance 200 as a heat source, as shown in FIG. The first bypass line R1 is opened through the direction switching valve 191, and the second bypass line R2 is opened through the second direction switching valve 192.

In addition, the branch line R4 is closed through the on / off valve 195, the expansion line R3 is opened through the third directional valve 193, and the inside of the air conditioning case 150 is bent. Inflow to bet flow mode is switched to flow.

On the other hand, the cooling water heated by the vehicle electrical component 200 is supplied to the cooling water heat exchanger 181b of the water-cooled heat exchanger 181 serving as the heat supply means 180.

In the second heating mode, the temperature control door 151 in the air conditioning case 150 is operated to close the passage bypassing the indoor heat exchanger 110, so that air is blown into the air conditioning case 150 by the blower Air passes through the evaporator 160 (operation stop), passes through the indoor heat exchanger 110, and is converted into hot air to be supplied to the interior of the vehicle, thereby heating the interior of the vehicle.

Next, the refrigerant circulation process will be described.

The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 100 after being compressed is introduced into the indoor heat exchanger 110 installed inside the air conditioning case 150.

The high-temperature, high-pressure gaseous refrigerant introduced into the indoor heat exchanger 110 is condensed while exchanging heat with the air blown into the air conditioning case 150 through the blower. At this time, air passing through the indoor heat exchanger 110 After changing to hot air, it is supplied to the interior of the vehicle, and the interior of the vehicle is heated.

Subsequently, the refrigerant discharged from the indoor heat exchanger 110 flows to the expansion line R3 through the third direction switching valve 193, and the refrigerant flowing to the expansion line R3 is the second refrigerant. After expanding under reduced pressure in the course of passing through the expansion means 120 to become a low-temperature low-pressure liquid refrigerant, and flows to the second bypass line (R2) to bypass the outdoor heat exchanger (130).

Thereafter, the refrigerant passing through the second bypass line R2 passes through the first bypass line R1 by the first direction switching valve 191, where the first bypass line R1 is used. The refrigerant passing through the heat exchange with the cooling water passing through the cooling water heat exchanger (181b) in the process of passing through the refrigerant heat exchanger (181a) of the water-cooled heat exchanger (181) to recover the waste heat of the vehicle electronics (200) As it flows into the compressor 100, the cycle as described above is recycled.

hemp. In the second heating mode of the heat pump mode (Fig. 6)

The dehumidification mode of the second heating mode of the heat pump mode is operated when the room dehumidification is required during the operation of the second heating mode of Fig.

Therefore, only the parts different from the second heating mode in Fig. 5 will be described.

During the dehumidification mode, the branch line R4 is further opened through the on-off valve 195 in the second heating mode.

In the dehumidifying mode, the temperature control door 151 in the air conditioning case 150 is operated to close the passage bypassing the indoor heat exchanger 110, so that the air blown into the air conditioning case 150 by the blower After passing through the evaporator 160, the refrigerant passes through the indoor heat exchanger 110 and is converted into hot air to be supplied to the interior of the vehicle, thereby heating the interior of the vehicle.

At this time, since the amount of the refrigerant supplied to the evaporator 160 is small, the air cooling performance is low, so that the change in the room temperature is minimized, and the air passing through the evaporator 160 is dehumidified smoothly.

Next, the refrigerant circulation process will be described.

The refrigerant passing through the compressor 100, the indoor heat exchanger 110, the second expansion means 120, and the second bypass line R2 is transferred to the first bypass line by the first diverter valve 191. In this case, some of the refrigerant passing through the first bypass line R1 passes through the refrigerant heat exchanger 181a of the water-cooled heat exchanger 181. Heat exchange with the cooling water passing through the e) is evaporated while recovering the waste heat of the vehicle electrical equipment 200, a part is supplied to the evaporator 160 through the branch line (R4) and the air flowing in the air conditioning case 150 and It will evaporate during the heat exchange process.

In this process, the air passing through the evaporator 160 is dehumidified, and the dehumidified air passing through the evaporator 160 is converted into hot air while passing through the indoor heat exchanger 110, Dehumidification is heated.

Then, the refrigerant having passed through the water-cooled heat exchanger 181 and the evaporator 160 is combined and then flows into the compressor 100, and recycles the cycle as described above.

100: compressor 110: indoor heat exchanger
115: Electric heater
120: second expansion means 121: orifice
130: outdoor heat exchanger 140: first expansion means
150: air conditioning case 151: temperature control door
160: Evaporator 170: Accumulator
180: Heat supply unit 181: Water-cooled heat exchanger
181a: refrigerant heat exchanger 181b: cooling water heat exchanger
191: first direction switching valve 192: second direction switching valve
193: third direction switching valve 195: on-off valve
200: electronics
R: refrigerant circulation line R1: first bypass line
R2: second bypass line R3: inflation line
R4: Branch Line

Claims (8)

Installed on the refrigerant circulation line (R), respectively, the compressor 100 for compressing and discharging the refrigerant, and is installed in the air conditioning case 150 is discharged from the air in the air conditioning case 150 and the compressor 100 An indoor heat exchanger (110) for exchanging the refrigerant, an evaporator (160) installed inside the air conditioning case (150) for exchanging air in the air conditioning case (150) and the refrigerant supplied to the compressor (100), and Is installed outside the air conditioning case 150 on the outdoor heat exchanger 130 for heat exchange between the refrigerant circulating the refrigerant circulation line (R) and the outside air, and on the refrigerant circulation line (R) of the inlet side of the evaporator (160) A second expansion means installed on the refrigerant expansion line R provided between the first expansion means 140 and the indoor heat exchanger 110 and the outdoor heat exchanger 130 to expand the refrigerant ( 120. A vehicle heat pump system comprising:
The refrigerant circulating through the refrigerant circulation line R is installed to connect the inlet refrigerant circulation line R of the first expansion means 140 and the outlet refrigerant circulation line R of the evaporator 160. A first bypass line R1 for selectively bypassing the first expansion means 140 and the evaporator 160,
In the heat pump mode, when the difference between the vehicle outside air temperature and the outlet refrigerant temperature of the outdoor heat exchanger 130 is equal to or greater than a predetermined temperature, and the inlet refrigerant pressure of the outdoor heat exchanger 130 is equal to or less than a reference value, the outdoor heat exchanger ( And a control unit for controlling defrosting of the system by determining that an implantation has occurred at 130). The method of claim 1,
The predetermined temperature is 10 ° C vehicle heat pump system, characterized in that. The method of claim 1,
The control unit, the vehicle heat pump system, characterized in that for controlling the system to increase the refrigerant pressure and temperature of the system during the defrost control. The method of claim 1,
On the first bypass line (R1) is provided a heat supply means 180 for supplying waste heat of the vehicle electronics 200 to the refrigerant flowing along the first bypass line (R1),
The heat supply unit 180 includes a refrigerant heat exchanging unit 181a through which the refrigerant flowing through the first bypass line R1 flows and a refrigerant heat exchanging unit 181a provided at one side of the refrigerant heat exchanging unit 181a, And a cooling water heat exchanger (181b) through which cooling water circulating through the cooling water heat exchanger (200) flows. In the control method of a vehicle heat pump system,
A first step (S1) of determining whether the system is in a heat pump mode;
As a result of the determination in the first step (S1), in the heat pump mode, the second step (S2) of determining whether the difference between the vehicle outside temperature and the refrigerant temperature of the outlet side of the outdoor heat exchanger 130 is more than a predetermined temperature;
A third step S3 of determining whether the refrigerant pressure of the inlet side of the outdoor heat exchanger 130 is equal to or less than a reference value when the determination result of the second step S2 is greater than or equal to a predetermined temperature;
And a fourth step (S4) for determining defrosting in the outdoor heat exchanger (130) and defrosting the system if the result of the determination in the third step (S3) is less than a reference value A method of controlling a heat pump system. The method of claim 5, wherein
The predetermined temperature of the second step (S2) is a control method of a vehicle heat pump system, characterized in that 10 ℃. The method of claim 5, wherein
The fourth step (S4), the control method of the vehicle heat pump system, characterized in that for controlling the system to increase the refrigerant pressure and temperature of the system during the defrost control. The method of claim 5, wherein
After performing the fourth step (S4), it is determined whether the defrost of the outdoor heat exchanger 130 is completed, and if the completion further comprises a fifth step (S5) to return to the first step (S1). Control method of a vehicle heat pump system, characterized in that.

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