Heat pump system in vehicle

A heat pump system in a vehicle connected with a refrigerant line through which refrigerant flows for controlling cooling/heating of a cabin of the vehicle, including a compressor for compressing refrigerant, an outdoor heat exchanger for condensing high temperature and high pressure refrigerant compressed at the compressor, and an expansion valve for expanding the refrigerant compressed thus, may include an indoor heat exchanger arranged between the compressor and the expansion valve connected to one another with the refrigerant line, and having a partitioned inside to form individual flow passages, and a first valve connected to the compressor, the outdoor heat exchanger and the indoor heat exchanger with the refrigerant line for changing a direction of a refrigerant flow according to cooling, heating, and dehumidifying modes of the vehicle to control the refrigerant flow along the refrigerant line.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2014-0044237 filed in Apr. 14, 2014, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a heat pump system in a vehicle. More particularly, the present invention relates to a heat pump system in a vehicle, which embodies heating, cooling and dehumidifying functions with one heat exchanger which also performs a function of an evaporator.

Description of Related Art

In general, an air conditioner in the vehicle includes an air conditioner module for cooling and heating a cabin in the vehicle.

The air conditioner module is configured to cool the cabin with a heat exchange medium owing to heat exchange of the heat exchange medium with the evaporator, or to heat the cabin with cooling water by introducing the cooling water to a heater in a process in which the heat exchange medium discharged as a compressor is driven circulates to the compressor again through a condenser, a receiver drier, an expansion valve and the evaporator.

In the meantime, recently, as people take growing interests in energy efficiency and environmental pollution day by day, development of an environmentally-friendly vehicle which can replace an internal combustion engine vehicle is on demand. The environmentally-friendly vehicle includes, in general, an electric vehicle which is driven taking fuel cell or electricity as a power source, or a hybrid vehicle which is driven by using an engine and a battery.

Of such environmentally-friendly vehicles, different from the air conditioner in a general vehicle, the air conditioner in the electric vehicle has no heater used therein, and the air conditioner applied to the electric vehicle is called, in general, the heat pump system.

Though the heat pump system is the same with a general principle in which, in a room cooling mode in a summer, high temperature and high pressure gaseous refrigerant compressed at the compressor drops a room temperature and humidity by evaporation at the evaporator after passed through the receiver drier and the expansion valve after the refrigerant is condensed at the condenser, in a room heating mode in a winter, the heat pump system uses high pressure gaseous refrigerant as a heater medium.

That is, in the room heating mode, the electric vehicle has the high temperature and high pressure gaseous refrigerant heat exchanging with outdoor air introduced, not to an outdoor condenser, but to an indoor condenser, through a valve such that the outdoor air heat exchanged thus makes a temperature of the vehicle cabin to rise as the outdoor air is introduced to the cabin of the vehicle while passing through a PTC (Positive Temperature Coefficient) heater.

And, the high temperature and high pressure gaseous refrigerant introduced to the indoor condenser is condensed as the refrigerant heat exchanges with the outdoor air and discharged as liquid refrigerant, again.

However, though the related art heat pump system is required to include a dehumidifying mode for removing moisture from a window of the vehicle in middle of operation of a cooling mode in a summer or a heating mode in a winter, in order to operate the dehumidifying mode, it is required to add a heat exchanger to the heat pump system. Consequently, a problem is caused, in that an entire system package increases due to addition of an element and complicated pipe layout, and a production cost increases.

Moreover, if the heat exchanger is provided to the cabin, mounting of 3-way valves on pipelines is required, to open/close the valves frequently causing noise and poor durability, and the increased pipelines causes a large pressure loss with a poor overall NVH (noise vibration harshness) performance.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a vehicle having advantages of embodying heating, cooling and dehumidifying functions with one heat exchanger which also performs a function of an evaporator.

Accordingly, various aspects of the present invention are directed to providing a heat pump system in a vehicle, in which one heat exchanger partitioned to perform an evaporator function altogether is applied thereto for embodying cooling, heating and dehumidifying modes for simplifying elements to reduce a production cost, reduce a pressure loss by reducing a pipe length and simplifying a layout of pipelines to improve an overall NVH performance of a vehicle.

According to various aspects of the present invention, a heat pump system in a vehicle connected with a refrigerant line through which refrigerant flows for controlling cooling/heating of a cabin of the vehicle, including a compressor for compressing refrigerant, an outdoor heat exchanger for condensing high temperature and high pressure refrigerant compressed at the compressor, and an expansion valve for expanding the refrigerant compressed thus, may include an indoor heat exchanger arranged between the compressor and the expansion valve connected to one another with the refrigerant line, and having a partitioned inside to form individual flow passages, and a first valve connected to the compressor, the outdoor heat exchanger and the indoor heat exchanger with the refrigerant line for changing a direction of a refrigerant flow according to cooling, heating, and dehumidifying modes of the vehicle to control the refrigerant flow along the refrigerant line.

The indoor heat exchanger may include a first header tank connected to the expansion valve with the refrigerant line, a second header tank connected to the first valve, and a heat exchanger portion provided between the first header tank and the second header tank and having an inside partitioned by a partition wall provided in a length direction thereof to form first, and second flow passages.

The second header tank may be partitioned with a diaphragm provided at a position matched to the partition wall for introducing the refrigerant to a relevant one of the flow passages in the heat exchanger portion when the refrigerant is introduced thereto.

The partition wall may be formed of a heat transfer preventive material which prevents heat transfer from taking place between the refrigerants passing through the first flow passage and the second flow passage.

The first valve may be a 4-way valve.

The refrigerant line connected between the first valve and the first flow passage may have a second valve provided thereto further.

The second valve may be connected to an inlet to the compressor with a connection line.

The second valve may be a 3-way valve for supplying the refrigerant introduced from the first valve to the first flow passage or for supplying the refrigerant introduced from the first valve and the first flow passage to the compressor through the connection line according to the heating, cooling, or dehumidifying mode of the vehicle.

The second valve, in the heating mode of the vehicle, may close the refrigerant line connected to the first flow passage and may supply the refrigerant introduced thereto from the first valve to the compressor through the connection line.

The second valve, when dehumidification is required in middle of the heating mode of the vehicle, may open the refrigerant line connected to the first flow passage for introduction of the refrigerant, introduced thereto through the first vale discharged from the outdoor heat exchanger, into the first flow passage.

In the cooling mode of the vehicle, the first valve may connect between an outlet of the compressor and the outdoor heat exchanger and connect between the indoor heat exchanger and the inlet to the compressor, and the second valve may become to be in communication with the first flow passage.

In the heating mode of the vehicle, the first valve may connect between the outlet of the compressor and the indoor heat exchanger, and between the outdoor heat exchanger and the inlet to the compressor, and the second valve may cut off communication with the first flow passage.

In the heating and dehumidifying modes of the vehicle, the first valve may connect between the outlet of the compressor and the indoor heat exchanger, and between the outdoor heat exchanger and the inlet to the compressor, and the second valve may become in communication with the first flow passage.

Thus, the heat pump system in a vehicle in accordance with various embodiments of the present invention has advantages of embodying the cooling, heating, and dehumidifying modes to simplify elements thereof compared to the related art, as well as to minimize a number of valves mounted to the pipelines to save a production cost and simplify a package by making one heat exchanger having a partitioned inside to perform a function of an evaporator altogether.

And, the reduction of a pipeline length and the simplification of layout reduce a pressure loss, to improve overall NVH performance of the vehicle, thereby permitting to improve general marketability of the vehicle and general efficiency of the heat pump system.

DETAILED DESCRIPTION

FIG. 1illustrates a block diagram of a heat pump system in a vehicle in accordance with various embodiments of the present invention.

Referring toFIG. 1, the heat pump system in a vehicle is connected with refrigerant line3through which refrigerant flows for controlling cooling/heating a cabin of a vehicle, and includes a compressor10for compressing the refrigerant, an outdoor heat exchanger (or outer heat exchanger)20for condensing high temperature and high pressure refrigerant compressed at the compressor10, and an expansion valve30for expanding the refrigerant compressed thus.

In this case, the heat pump system in a vehicle in accordance with various embodiments of the present invention further includes an indoor heat exchanger (or inner heat exchanger)40and a first valve50.

The indoor heat exchanger40is arranged between the compressor10and the expansion valve30connected to one another with the refrigerant line3, and has a partitioned inside to form individual flow passages46and47.

The indoor heat exchanger40includes first and second headers41and43, and a heat exchanger portion45.

The first header tank41is connected to the expansion valve30with the refrigerant line3, and the second header tank43is connected to the compressor10or the outdoor heat exchanger20through the first valve50, selectively.

And, the heat exchanger portion45is provided between the first header tank41and the second header tank43connecting the first header tank41and the second header tank43to each other, and has the inside thereof partitioned with a partition wall49provided in a length direction thereof to form the first and second flow passages46and47.

In this case, the partition wall49may be formed of a heat transfer preventive material for preventing heat transfer from taking place between the refrigerants respectively passing through the flow passages46and47if the refrigerants are introduced to, and pass through the flow passages46and47selectively according to operation of the first valve50.

The partition wall49may be constructed of a heat insulating board which prevents heat transfer.

Both of the first, and second flow passages46and47of the indoor heat exchanger40function as evaporators in the cooling mode of the vehicle.

Opposite to this, in the heating mode, the indoor heat exchanger40functions as a heater by introducing high temperature and high pressure refrigerant to the second flow passage47making the refrigerant to heat exchange with outdoor air, thereby introducing high temperature outdoor air to the cabin of the vehicle.

If dehumidification is required in this state, low temperature and low pressure refrigerant passed through the outdoor heat exchanger20is introduced to the first flow passage46of the indoor heat exchanger40to make the refrigerant to heat exchange with the outdoor air for directing low temperature outdoor air toward an inside surface of the window, thereby removing moisture from surfaces of the window.

That is, the indoor heat exchanger40having above function performs a function of two heat exchangers with the first, and second flow passages46and47.

In the meantime, in various embodiments, the second header tank43may have an inside partitioned with a diaphragm44provided at a position matched to the partition wall49for making refrigerants respectively from the compressor10and the outdoor heat exchanger20to be introduced to the respective flow passages46and47of the heat exchanger portion45.

And, the first valve50is connected to the compressor10, the outdoor heat exchanger20and the indoor heat exchanger40with the refrigerant line3, for changing a flow direction of the refrigerant according to the cooling, heating, or dehumidifying mode of the vehicle, thereby controlling the flow direction of the refrigerant flowing along the refrigerant line3.

The first valve50is a 4-way valve for controlling the flow direction of the refrigerant according to the mode of cooling, or heating of the cabin of the vehicle in a state the first valve50is connected to the compressor10, the outdoor heat exchanger20, and the first, and second flow passages46and47of the indoor heat exchanger40with the refrigerant line3.

In the meantime, in various embodiments, a second valve60may be provided to the refrigerant line3which is connected between the first valve50and the first flow passage46, further.

The second valve60is connected to an inlet to the compressor10with a connection line61.

In this case, the second valve60may be a 3-way valve for supplying refrigerant introduced from the first valve50to the first flow passage46or for supplying the refrigerant introduced from the first valve50and the first flow passage46to the compressor10through the connection line61according to the heating, cooling, or dehumidifying mode of the vehicle.

Hereafter, operation and effects of the heat pump system in a vehicle in accordance with various embodiments of the present invention will be described in detail.

FIG. 2illustrates an operation table in cooling, heating, and dehumidifying modes of a heat pump system in a vehicle in accordance with various embodiments of the present invention, andFIG. 3,FIG. 4andFIG. 5illustrate block diagrams showing operation states in cooling, heating, and dehumidifying modes of a heat pump system in a vehicle in accordance with various embodiments of the present invention, respectively.

Referring toFIG. 2andFIG. 3, if the driver operates the heat pump system in a vehicle in accordance with various embodiments of the present invention in the cooling mode to cool the cabin of the vehicle, the refrigerant is discharged from the compressor10in a high temperature and high pressure state and introduced to the first valve50.

In this case, the first valve50makes the refrigerant line3between the compressor10and the outdoor heat exchanger20connected within the first valve50for introducing the refrigerant introduced thereto from the compressor10to the outdoor heat exchanger20.

Then, the high temperature and high pressure refrigerant discharged from the compressor10is passed through, and condensed at, the outdoor heat exchanger20, passed through, and expanded at, the expansion valve30, and introduced to the first header tank41of the indoor heat exchanger40.

The refrigerant introduced to the first header tank41is passed through, and evaporates at, the first, and second flow passages46and47to a low temperature and low pressure state, while the outdoor air introduced to the vehicle heat exchanges with the low temperature and low pressure refrigerant to low temperature air and is introduced to the cabin of the vehicle for cooling the cabin of the vehicle.

That is, in the cooling mode of the vehicle, the indoor heat exchanger40performs a function of an evaporator, wherein the refrigerant passed through the expansion valve30passes through the heat exchanger portion45via the first header tank41and the first, and second flow passages46and47, and flows to the first valve50and the second valve60through the second header tank43.

In this case, the second valve60maintains a state in which the connection line61is opened, that is, the second valve60is in communication with the first flow passage46, and the refrigerant passed through the first flow passage46, and the refrigerant discharged through the second flow passage47and passed through the first valve50circulate to the compressor10.

Referring toFIG. 2andFIG. 4, if the driver operates the heat pump system in a vehicle in accordance with various embodiments of the present invention in the heating mode to heat the cabin of the vehicle, the high temperature and high pressure refrigerant discharged from the compressor10is introduced to the first valve50.

In this case, the first valve50makes the refrigerant lines3between the compressor10and the second flow passage47of the indoor heat exchanger40to be connected to each other within the first valve50for supplying the refrigerant introduced from the compressor10to the second flow passage47of the indoor heat exchanger40.

Then, the high temperature and high pressure refrigerant discharged from the compressor10passes through the second flow passage47through the second header tank43while heat exchanging with the external air introduced thereto from the outside of the vehicle, such that the external air having a temperature thereof risen by the heat exchange with the high temperature and high pressure refrigerant is introduced to the cabin of the vehicle to heat the cabin of the vehicle.

In this case, in the heating mode of the vehicle, the second valve60supplies the refrigerant introduced thereto from the first valve50to the compressor10through the connection line61in a state the second valve60closes the refrigerant line3connected to the first flow passage46, i.e., in a state communication of the second valve60with the first flow passage46is cut off.

Accordingly, in the heating mode of the vehicle, the refrigerant is introduced to the outdoor heat exchanger20through the second flow passage47of the indoor heat exchanger40and the expansion valve30The refrigerant is introduced to the second valve60by operation of the first valve50in a condensed state because the refrigerant passes has passed through the outdoor heat exchanger20. The refrigerant is then introduced to the compressor10again through the connection line61by way of valve60.

In the meantime, referring toFIG. 2andFIG. 5, in various embodiments, if dehumidification of the cabin is required in middle of the heating mode of the vehicle, the second valve60opens the refrigerant line3connected to the first flow passage46, i.e., the second valve60is made to be in communication with the first flow passage46, for introducing the refrigerant discharged from the outdoor heat exchanger20and introduced thereto through the first valve50to the first flow passage46.

That is, if the dehumidifying mode is operated together with the heating mode of the vehicle, a portion of the low temperature and low pressure refrigerant passed through the outdoor heat exchanger20is introduced to, and passes through, the first flow passage46by operation of the second valve60.

Then, the external air is cooled down by heat exchange with the low temperature and low pressure refrigerant being introduced to the first flow passage46, such that the external air in a low temperature state flows toward the inside surface of the window in the cabin of the vehicle, thereby removing the moisture from the surface of the window. In this case, since detailed description of directing an air flow of the air heat exchanged with the first flow passage46toward the inside surface of the window is known to persons skilled in this field of art, the detailed description will be omitted.

That is, if the dehumidifying mode comes into operation in middle of operation of the heating mode of the vehicle, the heat pump system in a vehicle in accordance with various embodiments puts the second valve60into operation such that the first flow passage46of the indoor heat exchanger40cools down the external air being introduced thereto from an outside of the system.

Accordingly, the heat pump system in a vehicle in accordance with various embodiments of the present invention can make one indoor heat exchanger40, which performs a function of an evaporator in the cooling mode and a function of a heater in the heating mode by the foregoing operation, to perform the cooling/heating modes, and the dehumidifying mode at the same time with the heating mode, of the cabin of the vehicle by operating the two valves of the first and second valves50and60.

Eventually, if the heat pump system in a vehicle in accordance with various embodiments of the present invention is applied, by making one heat exchanger having a partitioned inside to perform a function of an evaporator altogether, the cooling, heating, and dehumidifying modes can be embodied to simplify elements thereof compared to the related art, as well as to minimize a number of valves mounted to the pipelines to save a production cost and simplify a package.

And, the reduction of a pipeline length and the simplification of layout reduce a pressure loss, to improve overall NVH performance of the vehicle, thereby permitting to improve general marketability of the vehicle and general efficiency of the heat pump system.