Heat pump system for vehicle and method for controlling the same

Abstract

The present invention aims to provide a heating and dehumidification control method for a vehicle heat pump system that prevents overloading of the heat pump system and improves the performance of the heat pump system by controlling the temperature of the refrigerant circulating in the evaporator to a first set temperature higher than the set temperature when the outside air temperature exceeds a first set temperature range higher than the set temperature of the refrigerant circulating in the evaporator during the operation of the heating and dehumidification mode of the heat pump system under high load conditions, and conversely, controlling the temperature of the refrigerant circulating in the evaporator to a second set temperature higher than the set temperature and lower than the first set temperature when the outside air temperature is below a first set temperature range higher than the set temperature of the refrigerant circulating in the evaporator under low load conditions.

Description

Technology Field

[0001] The present invention relates to a heating and dehumidification control method for a vehicle heat pump system, and more specifically, to a heating and dehumidification control method for a vehicle heat pump system capable of controlling the flow of refrigerant for heating and dehumidification to satisfy high load or low load conditions according to the ambient temperature. Background Technology

[0003] Generally, to implement various operating modes such as heating mode, heating / dehumidification mode, cooling mode, battery temperature rise mode, and PE component and battery cooling mode, a vehicle heat pump system may be configured with a predetermined layout comprising a refrigerant circuit in which a compressor, an indoor condenser, an expansion valve, an outdoor condenser, a heat exchanger, and an evaporator are connected to enable refrigerant circulation, and a cooling water circuit in which a radiator, an integrated chiller for heat exchange with the refrigerant, PE components, and batteries are connected to enable cooling water circulation, for cooling PE (Power Electric) components and batteries.

[0004] When operating the heating and dehumidification mode of a conventional heat pump system, the flow of refrigerant circulating through the refrigerant circuit is set to a single path, so that the temperature of the refrigerant flowing inside the evaporator can be controlled to a set temperature.

[0005] Accordingly, dehumidification of the outside air passing through the evaporator can be achieved by the low-temperature refrigerant (refrigerant adjusted to a set temperature) flowing through the evaporator, and as the dehumidified outside air passes through the interior condenser and PTC heater and is heated to a high temperature and introduced into the vehicle interior, heating and dehumidification of the vehicle interior can be achieved.

[0006] However, when the heating and dehumidification mode of the above heat pump system is operated, regardless of high load or low load conditions depending on the ambient temperature, the flow of the refrigerant circulating in the refrigerant circuit is set to a single path so that the temperature of the refrigerant flowing inside the evaporator is controlled to a set temperature, which causes a problem of performance degradation of the heat pump system.

[0007] To elaborate, when the heating and dehumidification mode of the above heat pump system is operated, regardless of whether the outside air temperature passing through the evaporator is above the set temperature of the refrigerant flowing inside the evaporator or the high load condition or the low load condition, the flow of the refrigerant circulating in the refrigerant circuit is set to a single path so that the temperature of the refrigerant flowing inside the evaporator is controlled to the set temperature. This can lead to an overload of the heat pump system due to insufficient heat dissipation performance of the indoor condenser, and ultimately result in a degradation of the heat pump system's performance. The problem to be solved

[0009] The present invention is designed to solve the aforementioned conventional problems and aims to provide a heating and dehumidification control method for a vehicle heat pump system that prevents overloading of the heat pump system and improves the performance of the heat pump system. This is achieved by controlling the temperature of the refrigerant circulating in the evaporator to a first set temperature that is higher than the set temperature when the outside air temperature is higher than the set temperature of the refrigerant circulating in the evaporator under high-load conditions when the outside air temperature is higher than the set temperature of the refrigerant circulating in the evaporator under low-load conditions when the outside air temperature is lower than the set temperature of the refrigerant circulating in the evaporator under low-load conditions, thereby controlling the temperature of the refrigerant circulating in the evaporator to a second set temperature that is higher than the set temperature and lower than the first set temperature. means of solving the problem

[0011] To achieve the above-mentioned purpose, the present invention comprises: a compressor; an indoor condenser connected to the discharge side of the compressor by a first refrigerant line; a first expansion valve and a second expansion valve connected to the outlet of the indoor condenser by a second refrigerant line; an integrated chiller and an intermediate heat exchanger sequentially connected to the outlet of the first expansion valve by a third refrigerant line; an accumulator mounted on a fourth refrigerant line connected between the outlet of the intermediate heat exchanger and the compressor; an outdoor condenser connected to the first outlet of the second expansion valve by a fifth refrigerant line; a solenoid valve connected to the outlet of the outdoor condenser by a sixth refrigerant line passing through the intermediate heat exchanger; an evaporator whose inlet is connected to the outlet of the solenoid valve by a seventh refrigerant line, and whose outlet is connected to the inlet of the intermediate heat exchanger by an eighth refrigerant line; and a ninth refrigerant line extending from the second outlet of the second expansion valve and connected to the seventh refrigerant line. A method for controlling heating and dehumidification of a heat pump system for a vehicle, comprising: a cooling water circuit in which a radiator, a reservoir tank, a PE component, a multi-valve, and a battery are connected to allow cooling water flow through a cooling water line passing through the integrated chiller; wherein, according to one selected condition among a high load condition according to the ambient temperature, a first low load condition, and a second low load condition, the opening degree control or opening / closing control of the first expansion valve and the second expansion valve, and the opening / closing control of the solenoid valve are selectively performed by a controller, thereby allowing the temperature of the refrigerant circulating inside the evaporator to be controlled differently according to the high load condition according to the ambient temperature, the first low load condition, and the second low load condition when operating in a heating and dehumidification mode.

[0012] In the high-load condition, where the above-mentioned ambient temperature is higher than the maximum temperature of a first set temperature range that is higher than the set temperature of the refrigerant circulating in the evaporator, the first expansion valve is controlled to be closed or adjusted to an expansion opening toward the integrated chiller by the controller, the second expansion valve is controlled to be adjusted to an expansion opening toward the outdoor condenser or adjusted to a bypass opening, and the solenoid valve is controlled to be open, thereby controlling the temperature of the refrigerant circulating in the evaporator to be raised to a first set temperature that is higher than the set temperature.

[0013] In the first low-load condition, where the above ambient temperature is lower than or equal to the minimum temperature of a first set temperature range which is higher than the set temperature of the refrigerant circulating in the evaporator, and the temperature of the cooling water circulating in the cooling water circulation line is higher than or equal to the maximum temperature of the cooling water set temperature range, the first expansion valve is controlled by the controller to an expansion opening toward the integrated chiller, the second expansion valve is controlled to an expansion opening toward the ninth refrigerant line, and the solenoid valve is controlled to close, thereby controlling the temperature of the refrigerant circulating in the evaporator to a second set temperature which is higher than the set temperature and lower than the first set temperature.

[0014] In the second low-load condition, where the above ambient temperature is lower than or equal to the minimum temperature of a first set temperature range which is higher than the set temperature of the refrigerant circulating in the evaporator, and the temperature of the cooling water circulating in the cooling water circulation line is lower than or equal to the minimum temperature of the cooling water set temperature range, the first expansion valve is controlled by the controller to an expansion opening toward the integrated chiller, the second expansion valve is controlled to an expansion opening toward the outdoor condenser, and the solenoid valve is controlled to open, thereby controlling the temperature of the refrigerant circulating in the evaporator to a second set temperature which is higher than the set temperature and lower than the first set temperature. Effects of the invention

[0016] Through the means for solving the above-mentioned problem, the present invention provides the following effects.

[0017] According to the present invention, when operating the heating and dehumidification mode of a heat pump system, the temperature of the refrigerant circulating within the evaporator can be raised and controlled according to high-load or low-load conditions based on the ambient temperature. This allows for smooth dehumidification of the evaporator against the ambient air, as well as smooth heat dissipation performance of the indoor condenser for heating, thereby improving the performance of the heat pump system. Brief explanation of the drawing

[0019] FIG. 1 is a system circuit diagram illustrating a circulation path of a refrigerant under high load, as a heating and dehumidification control method for a vehicle heat pump system according to the present invention. FIG. 2 is a system circuit diagram illustrating the circulation path of a refrigerant at a first low load, as a heating and dehumidification control method for a vehicle heat pump system according to the present invention. FIG. 3 is a system circuit diagram illustrating the circulation path of a refrigerant during a second low load, as a heating and dehumidification control method for a vehicle heat pump system according to the present invention. Specific details for implementing the invention

[0020] The specific structural or functional descriptions described in the embodiments of this specification are merely illustrative for the purpose of explaining embodiments according to the concept of the present invention, and embodiments according to the concept of the present invention may be implemented in various forms. Furthermore, the invention should not be interpreted as being limited by the embodiments described in this specification, and should be understood to include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention.

[0021] In this specification, terms such as "first" and / or "second" may be used to describe various components, but said components are not limited by said terms. For the sole purpose of distinguishing one component from other components, for example, without departing from the scope of rights according to the concept of the present invention, a first component may be named a second component, and similarly, a second component may be named a first component.

[0022] Where in this specification it is stated that a component is "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, or that there may be other components in between. Conversely, where it is stated that a component is "directly connected" or "directly in contact" with another component, it should be understood that there are no other components in between. Other expressions used to describe the relationship between components, such as "between" and "immediately between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way.

[0023] Throughout this specification, the same reference numerals denote the same components. The terms used in this specification are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used in this specification, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0024] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0025] The attached FIGS. 1, 2, and 3 are system circuit diagrams for a heating and dehumidification control method for a vehicle heat pump system according to the present invention.

[0026] A vehicle heat pump system is configured to include a refrigerant circuit through which refrigerant circulates and a cooling water circuit through which cooling water circulates, in order to implement various operating modes such as heating mode, heating / dehumidification mode, cooling mode, battery temperature rise mode, and PE component and battery cooling mode.

[0027] As shown in FIGS. 1, 2 and 3, the above refrigerant circuit is configured to include a compressor (100), an indoor condenser (110), a first expansion valve (121), a second expansion valve (122), an outdoor condenser (130), an integrated chiller (140), an intermediate heat exchanger (150), an evaporator (160), an accumulator (170), etc.

[0028] The discharge side of the compressor (100) and the indoor condenser (110) are connected to allow refrigerant flow through the first refrigerant line (R1).

[0029] The refrigerant outlet of the above indoor condenser (110) is connected to the first expansion valve (121) and the second expansion valve (121), which are in the form of a three-way valve, by the second refrigerant line (R2). The end of the second refrigerant line (R2) branches into two branches centered on the "A" branch point and is connected to the first expansion valve (121) and the second expansion valve (122).

[0030] A third refrigerant line (R3) is connected to the outlet of the first expansion valve (121), and an integrated chiller (140) and an intermediate heat exchanger (150) are sequentially installed in the third refrigerant line (R3) so that refrigerant from the indoor condenser (110) can pass through the first expansion valve (121) and flow sequentially.

[0031] A fourth refrigerant line (R4) is connected between the refrigerant outlet of the intermediate heat exchanger (150) and the compressor (100), and an accumulator (170) is installed in the fourth refrigerant line (R4) to separate and store liquid refrigerant from the refrigerant flowing to the compressor (100).

[0032] The first outlet of the second expansion valve (122) is connected to the outdoor condenser (130) by the fifth refrigerant line (R5) so that the refrigerant from the indoor condenser (110) can pass through the second expansion valve (122) and flow to the outdoor condenser (130).

[0033] A sixth refrigerant line (R6) is connected to the outlet of the above outdoor condenser (130) and extends from the "B" branch point toward the evaporator (160) by passing through the intermediate heat exchanger (150), and a solenoid valve (180) is installed at the end of the sixth refrigerant line (R6) that extends from the "B" branch point by passing through the intermediate heat exchanger (150) to allow or block the flow of refrigerant to the evaporator (160).

[0034] The inlet of the above evaporator (160) is connected to the outlet of the solenoid valve (180) by the seventh refrigerant line (R7), and the outlet of the evaporator (160) is connected to the inlet of the intermediate heat exchanger (150) through which the refrigerant flowing along the third refrigerant line (R3) passes by the eighth refrigerant line (R8).

[0035] In addition, the ninth refrigerant line (R9) is connected between the second outlet of the second expansion valve (122) and the seventh refrigerant line (R7) connected between the solenoid valve (180) and the evaporator (160), so that the refrigerant from the indoor condenser (110) can pass through the second expansion valve (122) and flow to the evaporator (160) along the ninth refrigerant line (R9) and the seventh refrigerant line (R7).

[0036] Meanwhile, as illustrated in FIGS. 1, 2 and 3, the cooling water circuit of the vehicle heat pump system is configured to include an integrated chiller (140), a radiator (210), a reservoir tank (220), a PE component (230), a multi-valve (240), a battery (250), a heating heater (260), a first water pump (271) positioned between the PE component (230) and the multi-valve (240) to discharge cooling water toward the PE component (230), and a second water pump (272) positioned between the multi-valve (240) and the battery (250) to discharge cooling water toward the battery (250).

[0037] To this end, a radiator (210), a reservoir tank (220), a PE component (230), a multi-valve (240) for controlling the flow direction of the coolant, a battery (250), etc. are connected to allow the coolant to flow through a coolant line (WL) passing through the integrated chiller (140).

[0038] The present invention focuses on the fact that, when operating the heating and dehumidification mode of the heat pump system configured as above, the temperature of the refrigerant circulating inside the evaporator (160) can be raised and controlled according to high load or low load conditions based on the outside air temperature, thereby ensuring that the dehumidification operation of the evaporator (160) against the outside air is carried out smoothly, and that the heat dissipation performance of the indoor condenser (110) for heating is always smoothly exerted, and thereby the overall performance of the heat pump system can be improved.

[0039] To this end, when the heating and dehumidification mode of the heat pump system configured as above is operated, the opening degree of the first expansion valve (121) and the second expansion valve (222) and the opening and closing control of the solenoid valve (180) are selectively controlled by a controller (not shown) according to one of the selected conditions among the high load condition, the first low load condition, and the second low load condition based on the outside temperature. As a result, the temperature of the refrigerant circulating inside the evaporator (160) can be controlled differently from the set temperature (e.g., increased temperature control relative to the set temperature) according to the high load condition, the first low load condition, and the second low load condition based on the outside temperature. Accordingly, not only is the dehumidification operation of the evaporator (160) against the outside air carried out smoothly, but the excessive operating load of the indoor condenser (110) for heating is prevented, so that the heat dissipation performance of the indoor condenser (110) can always be smoothly exerted, thereby promoting an improvement in the overall performance of the heat pump system. there is.

[0041] Here, the specific operation flow of the heating and dehumidification control method for a vehicle heat pump system according to the present invention is as follows.

[0042] Heating and dehumidification mode under high load conditions

[0043] Figure 1 attached is a system circuit diagram illustrating the circulation path of a refrigerant under high load, as a heating and dehumidification control method for a vehicle heat pump system according to the present invention.

[0044] When the outside temperature is above the maximum temperature (e.g., 10°C) of the first set temperature range (e.g., 8°C to 10°C) which is higher than the set temperature of the refrigerant circulating in the evaporator (160) (e.g., about 2°C as the set temperature of the refrigerant in cooling mode), for a heating and dehumidification mode, the first expansion valve (121) is controlled to be closed or adjusted to an expansion opening toward the integrated chiller (140) by a controller (not shown), the second expansion valve (122) is controlled to be adjusted to an expansion opening toward the outdoor condenser (130) or adjusted to a bypass opening, and the solenoid valve (180) is controlled to be open.

[0045] Accordingly, the gaseous refrigerant compressed to a high temperature and high pressure state in the compressor (100) passes through the first refrigerant line (R1) and the indoor condenser (110) to be converted into a high temperature and high pressure liquid refrigerant, then passes through the second refrigerant line (R2) and flows from the “A” branch point to the second expansion valve (122), and when the high temperature and high pressure liquid refrigerant passes through the second expansion valve (122), it is converted into a low temperature and low pressure liquid refrigerant.

[0046] Subsequently, the refrigerant that has passed through the second expansion valve (122) enters the outdoor condenser (130) along the fifth refrigerant line (R5).

[0047] At this time, the outdoor condenser (130) is intended to perform heat exchange between the refrigerant passing through the interior of the outdoor condenser (130) and the outside air passing through the exterior of the outdoor condenser (130), and the refrigerant introduced into the outdoor condenser (130) can be cooled by dissipating heat to the outside air.

[0048] Next, the refrigerant discharged from the outlet of the outdoor condenser (130) travels along the sixth refrigerant line (R6), passes through the intermediate heat exchanger (150), and then flows to the solenoid valve (180) mounted at the end of the sixth refrigerant line (R6) extended from the "B" branch point.

[0049] At this time, when the refrigerant discharged from the outdoor condenser (130) flows along the sixth refrigerant line (R6) and passes through the intermediate heat exchanger (150), it can further reduce the temperature by exchanging heat with the refrigerant that has been discharged from the evaporator (160) after completing heat exchange with the outside air and has entered the intermediate heat exchanger (150) along the eighth refrigerant line (R8), as described later.

[0050] Subsequently, since the solenoid valve (180) is in an open state, the refrigerant from the outdoor condenser (130) through the intermediate heat exchanger (150) enters the evaporator (160), flows through the evaporator (160), and then flows toward the compressor (100) along the eighth refrigerant line (R8), the intermediate heat exchanger (150), and the fourth refrigerant line (R4).

[0051] At this time, the temperature of the liquid refrigerant entering the evaporator (160) is controlled by lowering the temperature in the outdoor condenser (130) as described above, and even if it is further controlled by lowering the temperature in the intermediate heat exchanger (150), it is controlled to a first set temperature (e.g., about 5°C) which is higher than the set temperature of the refrigerant circulating in the evaporator (e.g., about 2°C as the set temperature of the refrigerant in cooling mode).

[0052] Therefore, under high load conditions due to the outside temperature, not only is dehumidification of the outside air (e.g., 10°C or higher) passing through the evaporator (160) carried out smoothly, but the outside air that has continuously passed through the evaporator (160) also passes through the indoor condenser (110) and exchanges heat with the high-temperature refrigerant flowing inside the indoor condenser (110) and enters the indoor space, thereby enabling indoor heating.

[0053] To elaborate, when there is a high load condition due to the outside temperature, the temperature of the refrigerant circulating in the evaporator (160) is raised to a first set temperature (e.g., about 5°C) which is higher than the set temperature (e.g., about 2°C as the set temperature of the refrigerant in cooling mode). This allows for smooth dehumidification of the outside air (e.g., 10°C or higher) passing through the evaporator (160), and also ensures that the heat dissipation performance of the indoor condenser (110) is not insufficient, thereby enabling smooth indoor heating. Ultimately, this resolves issues such as operating overload and insufficient heat dissipation performance for the indoor condenser, thereby improving the performance of the heat pump system.

[0055] Heating and dehumidification mode under 1st low load condition

[0056] Figure 2 attached is a system circuit diagram illustrating the circulation path of a refrigerant at a first low load, as a heating and dehumidification control method for a vehicle heat pump system according to the present invention.

[0057] When the outside temperature is lower than the minimum temperature (e.g., 8°C) of the first set temperature range (e.g., 8°C to 10°C) which is higher than the set temperature of the refrigerant circulating in the evaporator (160) (e.g., about 2°C as the set temperature of the refrigerant in cooling mode), and the temperature of the cooling water circulating in the cooling water circulation line (WL) is higher than the maximum temperature (e.g., 10°C) of the cooling water set temperature range (e.g., 8°C to 10°C), the first expansion valve (121) is controlled to an expansion opening toward the integrated chiller (140) by a controller (not shown) for the heating dehumidification mode, the second expansion valve (122) is controlled to an expansion opening toward the evaporator (160) through the ninth refrigerant line (R9), and the solenoid valve (180) is closed.

[0058] Accordingly, the gaseous refrigerant compressed to a high temperature and high pressure state in the compressor (100) passes through the first refrigerant line (R1) and the indoor condenser (110) to be converted into a high temperature and high pressure liquid refrigerant, then passes through the second refrigerant line (R2) and flows from the “A” branch point to the first expansion valve (121) and the second expansion valve (122), and when the high temperature and high pressure liquid refrigerant passes through the first expansion valve (121) and the second expansion valve (122), it is converted into a low temperature and low pressure liquid refrigerant.

[0059] Subsequently, after the refrigerant that has passed through the second expansion valve (122) flows along the ninth refrigerant line (R9) through the second outlet of the second expansion valve (122), the solenoid valve (180) is in a closed state, so the refrigerant can flow from the ninth refrigerant line (R9) along the seventh refrigerant line (R7) to the evaporator (160).

[0060] At this time, since the refrigerant entering the evaporator (160) is converted into a low-temperature, low-pressure liquid refrigerant by the second expansion valve (122), the temperature of the refrigerant circulating inside the evaporator (160) is controlled to a second set temperature (e.g., about 2.1°C to 4.9°C) which is higher than the set temperature of the refrigerant (e.g., about 2°C as the set temperature of the refrigerant in cooling mode) and lower than the first set temperature (e.g., about 5°C).

[0061] In addition, when the low-temperature, low-pressure liquid refrigerant that has passed through the first expansion valve (121) passes through the integrated chiller (140) along the third refrigerant line (R3), it exchanges heat with the cooling water (e.g., cooling water at about 10°C) circulating in the cooling water circulation line (WL), and then flows toward the compressor (100) along the intermediate heat exchanger (150) and the fourth refrigerant line (R4).

[0062] Accordingly, when the first low load condition is based on the outside air temperature and the cooling water temperature, not only is dehumidification of the outside air (e.g., 8°C or lower) passing through the evaporator (160) carried out smoothly, but the outside air that has continuously passed through the evaporator (160) also passes through the indoor condenser (110) and exchanges heat with the high-temperature refrigerant flowing inside the indoor condenser (110) and enters the indoor space, thereby enabling indoor heating.

[0063] To elaborate, when the temperature of the refrigerant circulating inside the evaporator (160) is raised to a second set temperature (e.g., approximately 2.1°C to 4.9°C) which is higher than the set temperature (e.g., approximately 2°C as the set temperature of the refrigerant in cooling mode) and lower than the first set temperature (e.g., approximately 5°C), the dehumidification of the outside air (e.g., 8°C or lower) passing through the evaporator (160) is not only smoothly carried out, but the heat dissipation performance of the indoor condenser (110) is also not insufficient, allowing for smooth indoor heating. Consequently, the operating overload and insufficient heat dissipation performance of the indoor condenser can be resolved, thereby improving the performance of the heat pump system.

[0065] Heating and dehumidification mode under 2nd low load condition

[0066] Figure 3 attached is a system circuit diagram illustrating the circulation path of a refrigerant at a second low load, as a heating and dehumidification control method for a vehicle heat pump system according to the present invention.

[0067] When the outside temperature is lower than the lowest temperature (e.g., 8°C) of the first set temperature range (e.g., 8°C ~ 10°C) which is higher than the set temperature of the refrigerant circulating in the evaporator (160) (e.g., about 2°C as the set temperature of the refrigerant in cooling mode), and the temperature of the cooling water circulating in the cooling water circulation line (WL) is lower than the lowest temperature (e.g., 8°C) of the cooling water set temperature range (e.g., 8°C ~ 10°C), the first expansion valve (121) is controlled to an expansion opening toward the integrated chiller (140) by a controller (not shown) for the heating dehumidification mode, the second expansion valve (122) is controlled to an expansion opening toward the outdoor condenser (130), and the solenoid valve (180) is controlled to open.

[0068] Accordingly, the gaseous refrigerant compressed to a high temperature and high pressure state in the compressor (100) passes through the first refrigerant line (R1) and the indoor condenser (110) to be converted into a high temperature and high pressure liquid refrigerant, then passes through the second refrigerant line (R2) and flows from the “A” branch point to the first expansion valve (121) and the second expansion valve (122), and when the high temperature and high pressure liquid refrigerant passes through the first expansion valve (121) and the second expansion valve (122), it is converted into a low temperature and low pressure liquid refrigerant.

[0069] Subsequently, the refrigerant that has passed through the second expansion valve (122) enters the outdoor condenser (130) along the fifth refrigerant line (R5) and circulates, thereby exchanging heat with the outside air.

[0070] Next, the refrigerant discharged from the outlet of the outdoor condenser (130) travels along the sixth refrigerant line (R6), passes through the intermediate heat exchanger (150), and then flows to the solenoid valve (180) mounted at the end of the sixth refrigerant line (R6) extended from the "B" branch point.

[0071] At this time, when the refrigerant discharged from the outdoor condenser (130) flows along the sixth refrigerant line (R6) and passes through the intermediate heat exchanger (150), it can further reduce the temperature by exchanging heat with the refrigerant that has been discharged from the evaporator (160) after completing heat exchange with the outside air and has entered the intermediate heat exchanger (150) along the eighth refrigerant line (R8), as described later.

[0072] Subsequently, since the solenoid valve (180) is in an open state, the refrigerant from the outdoor condenser (130) through the intermediate heat exchanger (150) enters the evaporator (160), flows through the evaporator (160), and then flows toward the compressor (100) along the eighth refrigerant line (R8), the intermediate heat exchanger (150), and the fourth refrigerant line (R4).

[0073] At this time, the temperature of the liquid refrigerant entering the evaporator (160) is lowered in the outdoor condenser (130) as described above, and even if it is further lowered in the intermediate heat exchanger (150), it is raised to a second set temperature (e.g., about 2.1°C to 4.9°C) which is higher than the set temperature of the refrigerant circulating in the evaporator (e.g., about 2°C as the set temperature of the refrigerant in cooling mode) and lower than the first set temperature (e.g., about 5°C).

[0074] In addition, when the low-temperature, low-pressure liquid refrigerant that has passed through the first expansion valve (121) passes through the integrated chiller (140) along the third refrigerant line (R3), it exchanges heat with the cooling water (e.g., cooling water at about 8°C) circulating in the cooling water circulation line (WL), and then flows toward the compressor (100) along the intermediate heat exchanger (150) and the fourth refrigerant line (R4).

[0075] Accordingly, when the second low load condition is based on the outside air temperature and the cooling water temperature, not only is dehumidification of the outside air (e.g., 8°C or lower) passing through the evaporator (160) performed smoothly, but the outside air that has continuously passed through the evaporator (160) also passes through the indoor condenser (110) and exchanges heat with the high-temperature refrigerant flowing inside the indoor condenser (110) and enters the indoor space, thereby enabling indoor heating.

[0076] To elaborate, when the second low-load condition is applied according to the outside air temperature and the cooling water temperature, the temperature of the refrigerant circulating inside the evaporator (160) is raised to a second set temperature (e.g., approximately 2.1°C to 4.9°C) which is higher than the set temperature (e.g., approximately 2°C as the set temperature of the refrigerant in cooling mode) and lower than the first set temperature (e.g., approximately 5°C). This ensures that dehumidification of the outside air (e.g., 8°C or lower) passing through the evaporator (160) is carried out smoothly, and the heat dissipation performance of the indoor condenser (110) is not insufficient, thereby ensuring smooth indoor heating. Ultimately, this resolves the operating overload and insufficient heat dissipation performance of the indoor condenser, thereby improving the performance of the heat pump system.

[0077] As seen above, when operating the heating and dehumidification mode of the heat pump system, the flow path of the refrigerant is varied according to the high load condition, the first low load condition, and the second low load condition according to the outside air temperature, thereby allowing the temperature of the refrigerant circulating inside the evaporator (160) to be raised to different temperatures. This ensures that the dehumidification operation of the evaporator against the outside air is carried out smoothly, and the heat dissipation performance of the indoor condenser for heating is also smoothly utilized, thereby improving the performance of the heat pump system.

[0078] Although the present invention has been described in detail above as one embodiment, the scope of the present invention is not limited to the above-described embodiment, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also included within the scope of the present invention. Explanation of the symbols

[0080] 100: Compressor 110: Indoor condenser 121: 1st expansion valve 122: 2nd expansion valve 130: Outdoor condenser 140: Integrated chiller 150: Intermediate heat exchanger 160: Evaporator 170: Accumulator 180: Solenoid valve R1: 1st refrigerant line R2: 2nd refrigerant line R3: 3rd refrigerant line R4: 4th refrigerant line R5: 5th refrigerant line R6: 6th refrigerant line R7: 7th refrigerant line R8: 8th refrigerant line R9: 9th refrigerant line 210: Radiator 220: Reservoir Tank 230: PE Part 240: Multi-valve 250: Battery 260: Heating heater 271: 1st water pump 272: 2nd Water Pump WL: Coolant Line

Claims

Claim 1 A compressor; an indoor condenser connected to the discharge side of the compressor by a first refrigerant line; a first expansion valve and a second expansion valve connected to the outlet of the indoor condenser by a second refrigerant line; an integrated chiller and an intermediate heat exchanger sequentially connected to the outlet of the first expansion valve by a third refrigerant line; an accumulator mounted on a fourth refrigerant line connected between the outlet of the intermediate heat exchanger and the compressor; an outdoor condenser connected to the first outlet of the second expansion valve by a fifth refrigerant line; a solenoid valve connected to the outlet of the outdoor condenser by a sixth refrigerant line passing through the intermediate heat exchanger; an evaporator whose inlet is connected to the outlet of the solenoid valve by a seventh refrigerant line, and whose outlet is connected to the inlet of the intermediate heat exchanger by an eighth refrigerant line; and a ninth refrigerant line extending from the second outlet of the second expansion valve and connected to the seventh refrigerant line. A method for controlling heating and dehumidification of a heat pump system for a vehicle, comprising: a cooling water circuit in which a radiator, a reservoir tank, a PE component, a multi-valve, and a battery are connected to allow cooling water flow through a cooling water line passing through the integrated chiller; wherein, according to one selected condition among a high load condition according to the ambient temperature, a first low load condition, and a second low load condition, the opening degree control or opening / closing control of the first expansion valve and the second expansion valve, and the opening / closing control of the solenoid valve are selectively performed by a controller, thereby causing the temperature of the refrigerant circulating inside the evaporator to be controlled differently from the set temperature according to the high load condition according to the ambient temperature, the first low load condition, and the second low load condition when the heating and dehumidification mode is operated. Claim 2 A heating and dehumidification control method for a vehicle heat pump system according to claim 1, wherein, under the high load condition in which the ambient temperature is higher than the maximum temperature of a first set temperature range that is higher than the set temperature of the refrigerant circulating in the evaporator, the first expansion valve is controlled to be closed or adjusted to an expansion opening toward the integrated chiller by the controller, the second expansion valve is controlled to be adjusted to an expansion opening toward the outdoor condenser or adjusted to a bypass opening, and the solenoid valve is controlled to be open, thereby controlling the temperature of the refrigerant circulating in the evaporator to be raised to a first set temperature that is higher than the set temperature. Claim 3 A heating and dehumidification control method for a vehicle heat pump system according to claim 1, wherein, in the first low-load condition in which the ambient temperature is lower than or equal to the minimum temperature of a first set temperature range which is higher than the set temperature of the refrigerant circulating in the evaporator and the temperature of the cooling water circulating in the cooling water circulation line is higher than or equal to the maximum temperature of the cooling water set temperature range, the first expansion valve is controlled by the controller to an expansion opening toward the integrated chiller, the second expansion valve is controlled to an expansion opening toward the ninth refrigerant line, and the solenoid valve is controlled to close, thereby controlling the temperature of the refrigerant circulating in the evaporator to be raised to a second set temperature which is higher than the set temperature and lower than the first set temperature. Claim 4 A heating and dehumidification control method for a vehicle heat pump system according to claim 1, wherein, in the second low-load condition in which the ambient temperature is lower than or equal to the lowest temperature of a first set temperature range which is higher than the set temperature of the refrigerant circulating in the evaporator and the temperature of the cooling water circulating in the cooling water circulation line is lower than or equal to the lowest temperature of the cooling water set temperature range, the first expansion valve is controlled by the controller to an expansion opening toward the integrated chiller, the second expansion valve is controlled to an expansion opening toward the outdoor condenser, and the solenoid valve is controlled to open, thereby controlling the temperature of the refrigerant circulating in the evaporator to be raised to a second set temperature which is higher than the set temperature and lower than the first set temperature.

Images