KR20070039222A - The apparatus and the control method of heat pump system for car - Google Patents

Abstract

The present invention provides a heating control structure and method using a heat pump system for a vehicle that enables rapid heating as well as shortening the warm-up time of an engine by using a heat pump system for a vehicle that can perform both cooling and heating. As to; A heater core 20 installed at the rear side of the indoor heat exchanger 11 and detecting a temperature of the air after heat exchange, and a heater core 20 for heating the air introduced into the room by using the coolant of the engine 25. Temporary door 21 to block the air flow is installed in front of the water temperature sensor 22 for detecting the temperature of the coolant flowing into the heater core 20, the temperature sensor 23 and the water temperature sensor 22 Comprising a control unit for opening and closing the temp door 21 by comparing the temperature and water temperature sensed by; When the warm-up signal of the engine 25 is input during the heating, the temp door 21 in front of the heater core 20 is opened. When the temperature of the downstream side of the indoor heat exchanger 11 is higher than the cooling water temperature, the temp door 21 is closed. Otherwise, the temp door 21 is opened.

Therefore, according to the present invention, the warm-up speed of the engine 25 may be increased by using the heating heat of the heat pump system, and the indoor heating may be more quickly performed by opening and closing the temporal door 21.

Heat Pump, Defrost, Heater Core, Coolant Temperature, Warm Up, Temp Door, Heat Exchange, Temperature Reversal

Description

Automotive heat pump system and its control method {The Apparatus and the Control Method of Heat Pump System for Car}

1 is a configuration diagram showing a conventional automotive heat pump system.

Figure 2 is a block diagram showing a heat pump system for a vehicle according to the present invention.

Figure 3 is a refrigerant circuit diagram showing the refrigerant flow at the time of cooling in the heat pump system for automobiles of the present invention.

4 is a refrigerant circuit diagram showing a refrigerant flow during heating in the heat pump system for a vehicle of the present invention.

5 is a refrigerant circuit diagram showing the refrigerant flow during the dehumidification heating in the heat pump system for a vehicle of the present invention.

Figure 6 is a graph showing the change in the cooling water temperature and the indoor side heat exchanger downstream temperature during heating in the automotive heat pump system according to the present invention.

7 is a flowchart illustrating a method for controlling a heat pump system for a vehicle according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: Compressor 11: Indoor Heat Exchanger

12: outdoor heat exchanger 13: internal heat exchanger

14: expansion valve 15: evaporator

16: Accumulator 17,17 ': Shut-off valve

18,18 ': Three way valve

20: Heater Core 21: Temp.Door

22: water temperature sensor 23: temperature sensor

24: Fan 25: Engine

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump system for an automobile, which enables heating to be performed simultaneously using a cooling system of an automobile. In particular, the warm-up time of an engine can be shortened and heating can be performed early. The present invention relates to a heating control structure and a method using a heat pump system for a vehicle that is enabled.

In general, a heat pump system is an air conditioning system that simultaneously performs cooling and heating by using one refrigerant system, and when heating, the refrigerant is circulated in the opposite direction of cooling. Therefore, the heat pump system includes a compressor for compressing a refrigerant, an indoor heat exchanger for exchanging heat between the refrigerant and the inlet air, an outdoor heat exchanger for exchanging heat between the external air and the refrigerant, an expansion valve for depressurizing the refrigerant, and a flow of the refrigerant. A direction control valve for changing the direction is provided.

In the heat pump system, the refrigerant is circulated through the compressor, the outdoor heat exchanger, the expansion valve, the indoor heat exchanger, and the path of the compressor during the cooling, and during the heating, the refrigerant, the indoor heat exchanger, the expansion valve, the outdoor heat exchanger, Circulated by path In other words, while cooling, the indoor heat exchanger is operated as an evaporator and the outdoor heat exchanger is operated as a condenser, but when heating, the indoor heat exchanger is operated as a condenser and the outdoor heat exchanger is operated as an evaporator.

However, there is a disadvantage in that the energy consumption of the heat pump system is applied to the automobile as it is. That is, the car is equipped with a heater core system (Heater Core) system that can heat the room using the coolant of the hot engine, it is possible to perform heating without consuming additional energy. However, in the case of using a heat pump system having a general structure, since the compressor must be driven even during heating, energy consumption for driving the compressor is essential.

As a result, it is preferable that the heat pump system used in an automobile be operated only for a predetermined time after starting the engine, and when the temperature of the engine coolant reaches a certain temperature or more, it is necessary to stop the operation of the heat pump system. Accordingly, various types of heat pump systems for automobiles have been developed.

1 shows a conventional heat pump system for a vehicle, in which heat exchange is performed between refrigerants and only one indoor heat exchanger is provided.

The automotive heat pump system includes a compressor (50) for compressing a refrigerant, an outdoor heat exchanger (51) partially exposed to the outside of the vehicle body, an expansion valve (52) for lowering the pressure of the refrigerant, and An indoor heat exchanger 53 disposed on an inflow path, an internal heat exchanger 55 for exchanging heat between a high pressure refrigerant and a low pressure refrigerant, and a parallel heat exchanger between the refrigerant and the coolant. A coolant heat exchanger (56) in which heat exchange is performed, an accumulator (54) installed on a coolant path flowing into the compressor (50), and separating a gas coolant and a liquid coolant, It is comprised by the several direction switching valve 57. As shown in FIG.

The conventional heat pump system for a vehicle may perform cooling, heating, or dehumidification heating by changing a flow path of a refrigerant according to a change in an air conditioning mode or a change in rotation speed of a compressor.

At the time of cooling, the refrigerant flows through the compressor 50, the outdoor heat exchanger 51, the high pressure side 55a of the internal heat exchanger 55, the expansion valve 52, the indoor heat exchanger 53, the accumulator 54, It flows through the low pressure side 55b of the internal heat exchanger 55 to the path returned to the compressor 50. That is, the outdoor heat exchanger 51 acts as a condenser, and the indoor heat exchanger 53 acts as an evaporator so that the inlet air is heated while passing through the indoor heat exchanger 53 to cool the room.

During heating or dehumidification, the refrigerant passes through the compressor 50, the indoor heat exchanger 53, the expansion valve 52, the outdoor heat exchanger 51, the accumulator 54, and the compressor 50. Therefore, the indoor heat exchanger 53 serves as a condenser to heat the air flowing into the room, and the outdoor heat exchanger 51 becomes an evaporator to vaporize the refrigerant. At this time, since the external air is heated to some extent while passing through the coolant heat exchanger 56, the outdoor heat exchanger 51 exchanges heat with the refrigerant, so that frost is not generated in the outdoor heat exchanger 51 even when the outdoor air temperature is low. Will not.

However, the conventional heat pump system for automobiles has a problem of generating fog while simultaneously condensing water rapidly evaporates when switching from cooling to heating.

That is, since one indoor heat exchanger 53 positioned on the air passage into which air flows acts as an evaporator when cooling and acts as a condenser when heating, it is generated when acting as an evaporator when switching from cooling to heating. Condensate evaporates rapidly. Therefore, the humidity of the air flowing into the room becomes high, causing discomfort, and forming a fog in the front window to obstruct the driver's vision, and when the outside temperature is low, the ice is frozen in the front window to form a frost. It is dangerous.

The present invention has been made in order to solve the above-described problems, an object of the present invention is to provide a heat pump system for an automobile capable of rapid heating or opening the engine warm-up speed through the opening and closing of the temporal door.

Another object of the present invention is to provide a heat pump system for an automobile that can be operated in conjunction with a heater core system capable of heating a room using cooling water to reduce energy consumption.

In addition, another object of the present invention is to provide a heat pump system for an automobile having a heating indoor heat exchanger and an evaporator separately to prevent generation of fog due to evaporation of condensate.

In addition, an object of the present invention is to provide a method for controlling a heat pump system for a vehicle, in which heat exchange between an engine coolant and air heated by an air conditioner is performed, thereby enabling adjustment of a heating speed and an engine warm-up speed.

According to the heat pump system for automobiles of the present invention for achieving the above object, the compressor for compressing and discharging the refrigerant, the indoor heat exchanger is a heat exchange between the refrigerant from the compressor and the air introduced into the room, the pressure of the refrigerant An expansion valve for lowering, an outdoor heat exchanger for exchanging heat between the refrigerant and the outside air, an evaporator for cooling the air through heat exchange between the air flowing into the room and the refrigerant, and a heat exchange between the high pressure refrigerant and the low pressure refrigerant An automotive heat pump system comprising an internal heat exchanger and an accumulator for separating a liquid refrigerant from a refrigerant having undergone secondary heat exchange; A temperature sensor installed at the rear side of the internal heat exchanger to sense the temperature of the heat-exchanged air, and a temper installed at the front of the heater core that heats the air introduced into the room by using the coolant of the engine. It includes a door, a water temperature sensor for sensing the temperature of the cooling water flowing into the heater core, and a control unit for opening and closing the temp door by comparing the temperature and the water temperature detected by the temperature sensor and the water temperature sensor.

In addition, according to the heat pump system for a vehicle of the present invention, the control unit opens the temp door when the engine warms up to heat the cooling water of the heater core by heating heat by the indoor heat exchanger, or the temp door when rapid heating is required. To close the air heated by the indoor heat exchanger immediately discharged into the room.

In addition, according to the control method of a heat pump system for a vehicle of the present invention, a first step of checking whether the vehicle is in heating mode when the vehicle is started, and a second step of opening the temp door in front of the heater core when an engine warm-up signal is input; A third step of comparing the temperature of the downstream side heat exchanger and the cooling water temperature when the engine warm-up signal is not input in the second stage; and closing the temporal door when the temperature of the downstream side of the indoor heat exchanger is higher than the cooling water temperature in the third stage. Otherwise, the fourth step of opening the temp door.

In addition, according to the control method of a heat pump system for a vehicle of the present invention, if a rapid heating signal is input in the second step, the engine warm-up signal is ignored.

The above features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are based on the principle that the inventor can appropriately define the concept of terms in order to explain the invention in the best way. It should be interpreted as meanings and concepts corresponding to

Figure 2 is a block diagram showing a heat pump system for a vehicle according to the present invention, Figure 3 is a refrigerant circuit diagram showing a refrigerant flow at the time of cooling in the automotive heat pump system of the present invention, Figure 4 is a refrigerant during heating 5 is a refrigerant circuit diagram showing a flow, and FIG. 5 is a refrigerant circuit diagram showing a refrigerant flow during dehumidification heating. In addition, Figure 6 is a graph showing a change in the cooling water temperature and the downstream temperature of the indoor heat exchanger during heating in the automotive heat pump system according to the present invention, Figure 7 is a heat pump system control method for automobiles according to the present invention The flow chart shown.

An automotive heat pump system according to the present invention includes a compressor 10 for compressing and discharging a refrigerant, an indoor heat exchanger 11 in which heat exchange is performed between the refrigerant from the compressor 10 and air introduced into the room; An expansion valve 14 for lowering the pressure of the refrigerant, an outdoor heat exchanger 12 for exchanging heat between the refrigerant and the outside air, and an evaporator 15 for cooling the air through heat exchange between the air flowing into the room and the refrigerant. And an internal heat exchanger 13 through which heat exchange is performed between the high-pressure side refrigerant and the low-pressure side refrigerant, an accumulator 16 for separating the liquid refrigerant from the refrigerant having undergone secondary heat exchange, and 2 for adjusting the flow direction of the refrigerant. Three-way valves 18 and 18 'and two shutoff valves 17 and 17' which block the flow of refrigerant.

In addition, a heater door 20 for heating the air blown by the fan 24 using the coolant of the engine 25 and a temporal door installed at the front side of the heater core 20 to block the flow of air. 21 is installed. In addition, a temperature sensor 23 is installed on the rear side of the indoor heat exchanger 11 to sense the temperature of the heat-exchanged air, and the water temperature sensor 22 detects the temperature of the coolant flowing into the heater core 20. ) Is installed, by comparing the temperature of the indoor heat exchanger 11 and the downstream temperature detected by the temperature sensor 23 and the water temperature sensor 22 with the cooling water temperature to open and close the temporal door 21 and according to the air conditioning type. A control unit 30 is provided to open and close the shutoff valves 17 and 17 '.

Automotive heat pump system of the present invention configured as described above is operated in the cooling mode or heating mode by changing the flow direction of the refrigerant by using the shut-off valve 17, 17 'and three-way valve (18, 18'), heating By comparing the wake temperature of the indoor heat exchanger 11 and the temperature of the cooling water, opening and closing the temporal door 21 speeds up the engine warm-up speed or speeds up the initial heating speed.

When the heat pump system is controlled to be cooled, the first shutoff valve 17 is opened and the second shutoff valve 17 'is shut off. Therefore, the refrigerant discharged from the compressor 10 flows to the outdoor heat exchanger 12 by the first three-way valve 18, and the refrigerant condensed in the outdoor heat exchanger 12 passes through the first shutoff valve 17. Pass the high pressure side of the internal heat exchanger (13). Subsequently, the pressure drops while passing through the expansion valve 14, and flows to the evaporator 15 by the second three-way valve 18 ′. In the evaporator 15, the fan 24 is evaporated through heat exchange with ambient air. Air blown by the cooling) to be discharged into the room. After the refrigerant from the evaporator 15 passes through the accumulator 16, the liquid refrigerant is separated and passes through the low pressure side of the internal heat exchanger 13, and is completely vaporized through heat exchange with the refrigerant on the high pressure side. Return to).

When the heat pump system is controlled by heating, the first shutoff valve 17 is shut off and the second shutoff valve 17 'is opened. Therefore, the refrigerant discharged from the compressor 10 flows to the indoor heat exchanger 11 by the first three-way valve 18, and the air blown by the fan 24 by condensation inside the indoor heat exchanger 11. Is heated and discharged to the room. Subsequently, the pressure drops through the expansion valve 14 via the high pressure side of the internal heat exchanger 13, and flows to the outdoor heat exchanger 12 by the second three-way valve 18 ′. In the outdoor heat exchanger 12, the refrigerant evaporates through heat exchange with ambient air, and passes through the accumulator 16 through the open second shutoff valve 17 ′. Subsequently, while passing through the low pressure side of the internal heat exchanger 13, the refrigerant is completely vaporized through heat exchange with the refrigerant on the high pressure side, and then returned to the compressor 10.

When the heat pump system is controlled by dehumidification heating, both the first blocking valve 17 and the second blocking valve 17 'are blocked to limit the flow of unnecessary refrigerant. Therefore, the refrigerant discharged from the compressor 10 flows to the indoor heat exchanger 11 by the first three-way valve 18, and the air blown by the fan 24 is heated by condensation in the indoor heat exchanger 11. To be discharged into the room. Subsequently, the pressure drops through the expansion valve 14 through the high pressure side of the internal heat exchanger 13 and flows to the evaporator 15 by the second three-way valve 18 '. In the evaporator 15, the refrigerant is evaporated through heat exchange with the ambient air. In this process, water vapor in the air condenses on the surface of the evaporator 15, thereby lowering the humidity of the blown air. After the refrigerant from the evaporator 15 passes through the accumulator 16, the liquid refrigerant is separated and passes through the low pressure side of the internal heat exchanger 13, and is completely vaporized through heat exchange with the refrigerant on the high pressure side. Return to).

The control of the dehumidification amount during the dehumidification heating is performed by adjusting the second three-way valve 18 'and the second shut-off valve 17'. That is, to reduce the amount of dehumidification, the second three-way valve 18 'supplies the refrigerant from the expansion valve 14 to the outdoor heat exchanger 12 side, and the second shut-off valve 17' is opened so that The refrigerant flows through the same path. As a result, the amount of dehumidification can be adjusted by changing the flow direction of the refrigerant using the second three-way valve 18 '.

In addition, when the heat exchange between the outside air and the refrigerant is made in the outdoor heat exchanger 12 during heating or dehumidification heating, ice may be frozen in the outdoor heat exchanger 12 when the external temperature is low. At this time, the refrigerant is flowed in the same path as the cooling, so that the high-temperature refrigerant discharged from the compressor 10 flows into the outdoor heat exchanger 12 to remove the ice formed in the outdoor heat exchanger 12, defrost mode Can be controlled by Of course, after a certain period of time it is natural to flow the refrigerant in the same path as the original to achieve the original purpose.

Here, the internal heat exchanger 13 plays an important role in both cooling and heating, thereby improving the performance of the system through temperature control of the refrigerant. That is, when cooling, the efficiency of the system is improved by lowering the refrigerant temperature at the inlet side of the expansion valve 14 to lower the pressure at the high pressure side. When heating, the refrigerant temperature at the suction side of the compressor 10 is increased to increase the efficiency of the compressor ( Increasing the discharge temperature of 10) improves the efficiency of the system and prevents liquid refrigerant from entering the compressor.

Here, the heating of the vehicle interior may be performed by using the heater core 20 separately from the heat pump system. The temp door 21 in front of the heater core 20 may be heated according to the temperature of the coolant and the driving conditions of the vehicle. By opening and closing, the vehicle warms up quickly or the heating speed is increased.

When starting the car in a cold place, the time required for warming up is long if the coolant temperature for cooling the engine 25 is too low. Therefore, when starting a car in a cold place, the time taken for warm-up of the engine 25 is shortened by shortening the circulation path of the cooling water and increasing the temperature of the cooling water rapidly.

In addition, in most cases, the heating is performed along with the start of the vehicle, and the temperature of the air is rapidly increased by the heat of heating by the heat pump system. Therefore, when heating is performed simultaneously with starting in a cold place, a temperature reversal phenomenon occurs in which the temperature of the cooling water is lower than the temperature of the air warmed by the heat pump system at the beginning of the starting. Of course, when the engine 25 is driven for a predetermined time or more, the water temperature of the cooling water is higher than the temperature caused by the heating heat of the heat pump system, and it is natural that the heating using the heater core 20 is effective.

Accordingly, in the present invention, the temperature Tw of the coolant flowing into the heater core 20 is sensed by the water temperature sensor 22, and the indoor heat exchanger 11 wakes up, which is the temperature of the air that has been heat-exchanged in the indoor heat exchanger 11 After detecting the side temperature Ta by the temperature sensor 23, it is determined whether the heat exchange between the air downstream of the indoor heat exchanger 11 by the heater core 20 and the cooling water is performed by the heater core 20.

When the engine 25 of the vehicle is started, it is checked whether it is being heated, and if it is being heated, it is checked whether the engine 25 is warmed up. When the engine 25 is warming up, since the cooling water temperature Tw is lower than the air temperature Ta as the initial start, the temp door 21 in front of the heater core 20 is opened. Accordingly, the coolant inside the heater core 20 and the air that has undergone heat exchange by the indoor heat exchanger 11 exchange heat with each other. Therefore, the temperature of the coolant circulated to the engine 25 is quickly increased, thereby increasing the warm-up speed of the engine 25. Of course, since the heat exchange between the coolant and the air means to lose the heating heat, when rapid heating is required, the heating is performed quickly by closing the temp door 21 regardless of whether the engine 25 is warmed up.

When the engine is not warmed up, the cooling water temperature Tw detected by the water temperature sensor 22 is compared with the air temperature Ta after the indoor heat exchanger 11 detected by the temperature sensor 23. If the temperature Ta is higher than the cooling water temperature Tw, only the air heated by the internal heat exchanger 11 without the heat exchange by the heater core 20 by closing the temp door 21 is indoors. To get into In addition, when the cooling water temperature Tw sensed by the water temperature sensor 22 is equal to or higher than the temperature Ta, the air heated by the internal heat exchanger 11 is opened by opening the temp door 21 so that the heater core 20 is heated. It is heated again by means of being introduced into the room. As a result, the temperature of the air is not lowered by the heater core 20 introduced into the room, but the heating rate is increased by allowing the heater core 20 to be increased through heat exchange with the heater core 20.

Although the preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to such specific embodiments, and those of ordinary skill in the art are appropriately within the scope described in the claims of the present invention. Changes will be possible.

As described above, the heating control structure and the method using the heat pump system for a vehicle of the present invention can increase the warm-up speed of the engine 25 by using the heating heat of the heat pump system when heating is performed simultaneously with starting. In addition, by comparing the cooling water temperature (Tw) and the downstream side temperature (Ta) of the internal heat exchanger 11, opening and closing the temporal door 21 has an effect of performing indoor heating more quickly.

In addition, according to the automotive heat pump system of the present invention, by installing both the evaporator 15, the cooling heat exchanger and the indoor heat exchanger 11, the heat exchanger for heating to prevent the increase of humidity and the generation of fog when switching from cooling to heating. There are other effects that can be.

Further, according to the automotive heat pump system of the present invention, the compressor 10 is protected by heating the refrigerant on the suction side of the compressor 10 through the internal heat exchanger 13 so that the liquid refrigerant does not flow into the compressor 10. There are other effects that can be done.

Further, according to the automotive heat pump system of the present invention, the high pressure side of the internal heat exchanger 13 is all just before the expansion valve 14 and the low pressure side is present at the suction side of the compressor 10, so the efficiency and performance of the system. There is another effect that can be maximized.

Claims (5)

A compressor (10) for compressing and discharging the refrigerant, an indoor heat exchanger (11) for exchanging heat between the refrigerant from the compressor (10) and air introduced into the room, an expansion valve (14) for lowering the pressure of the refrigerant; And an outdoor heat exchanger 12 through which heat is exchanged between the refrigerant and the outside air, an evaporator 15 for cooling the air through heat exchange between the air flowing into the room and the refrigerant, and between the high pressure refrigerant and the low pressure refrigerant. In an automotive heat pump system including an internal heat exchanger (13) in which heat exchange is performed, and an accumulator (16) for separating a liquid refrigerant from a refrigerant having undergone secondary heat exchange, Heater core (Heater) is installed on the rear side of the indoor heat exchanger (11) for detecting the temperature of the heat exchanged air and heat the air flowing into the room using the coolant of the engine (25) Temp. Door (21) installed in front of the core 20 to block the flow of air, a water temperature sensor 22 for detecting the temperature of the coolant flowing into the heater core 20, and the temperature sensor And a control unit (30) which opens and closes the temporal door (21) by comparing the temperature detected by the water temperature sensor (22) and the water temperature. The method of claim 1, The control unit may heat the cooling water of the heater core 21 by heating heat by the indoor heat exchanger 11 by opening the temp door 21 when the engine warms up. Pump system. The method of claim 1, The control unit, when rapid heating is required, the heat pump system for a vehicle, characterized in that to close the temp door (21) so that the air heated by the indoor heat exchanger (11) is immediately discharged to the room. In the method of controlling the automotive heat pump system of claim 1, A first step of checking whether the vehicle is in heating mode when the vehicle is started, a second step of opening the temporal door 21 in front of the heater core 20 when the warm-up signal of the engine 25 is input, and the engine in the second step (25) If the warm-up signal is not input, a third step of comparing the air temperature Ta and the cooling water temperature Tw of the indoor heat exchanger 11 and the downstream air temperature of the indoor heat exchanger 11 in the third step; And a fourth step of closing the temporal door (21) if Ta is higher than the cooling water temperature (Tw) and otherwise opening the temporal door (21). The method of claim 4, wherein The second step is to control the heat pump system, characterized in that to ignore the engine warm-up signal when the rapid heating signal is input.

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