DESC:CROSS REFERENCE TO RELATED APPLICATION
This application is based on and derives the benefit of Indian Provisional Application 202141010978 filed on 15/03/2021, the contents of which are incorporated herein by reference.

TECHNICAL FIELD
[001] The embodiments herein generally relate to vehicular cooling systems and more particularly, to refrigerant flow paths and methods for circulating a refrigerant in the vehicular cooling system.

BACKGROUND
[002] An extremely large percentage of the world's vehicles run on gasoline i.e., vehicles are operated using an internal combustion engine. The use of vehicles with I.C. engines has few disadvantages such as price fluctuations and a generally upward pricing trend in the cost of gasoline due to the finite size and limited regional availability of fossil fuels, both of which can have a dramatic impact at the consumer level. Further, combustion of fossil fuel is one of the primary sources of carbon dioxide emission, which is the leading contributor to global warming. Accordingly, considerable effort has been spent on finding alternative drive systems for use in both personal and commercial vehicles.
[003] Many automotive companies have come up with the advanced electric vehicle (EV) to make the vehicles environment friendly and pollution free. However, still there are lots of improvements to be made in certain technology areas of electric vehicles which affect range of the electric vehicles. One challenge faced by electric vehicle designers includes the sensitivity of the electric vehicle batteries to temperature. More specifically, the maximum charge current and the maximum discharge current of the batteries vary based on battery temperature, among other things. The temperature of the battery may vary during operation due to chemical reactions taking place within the battery as well as the ambient temperature of the environment in which the vehicle is positioned. For example, the maximum charging current of a battery may be significantly reduced when the temperature of the battery is below a predetermined limit. Battery charging and discharging efficiency may also be less than optimal when the temperature of the battery is above a predetermined operating limit.
[004] Conventional, vehicle thermal management systems are complex. For cooling the battery of a vehicle powered by a conventional internal combustion engine, air cooling by the natural flow of air was sufficient, but for cooling a high voltage battery with a voltage of 12V or higher which is mounted in an HV or an EV, air cooling by the natural flow of air is not sufficient.
[005] In a typical air-cooled battery pack, ambient air from ambient atmosphere is directed across battery cells in the battery pack and is subsequently exhausted from the battery pack. However, the typical air-cooled battery pack has a major challenge in maintaining a temperature of the battery pack within a desired temperature range. In particular, a maximum operating temperature of the battery cells can often be less than a temperature of ambient air utilized to cool the batteries. In this situation, it is impossible to maintain the battery cells within a desired temperature range in an air-cooled battery pack.
[006] Other systems that actively circulate coolant through a cooling system use expensive refrigerant chillers, thermal expansion valves (or TXVs), or solenoids to cool the battery even under hot ambient conditions. These arrangements require more parts, greater power usage and are typically more expensive than the arrangements discussed herein.
[007] Therefore, there exists a need for refrigerant flow paths and methods for circulating a refrigerant in the vehicular cooling system, which eliminates the aforementioned drawbacks.

OBJECTS
[008] The principal object of an embodiment herein is to provide refrigerant flow paths for circulating a refrigerant in a vehicular cooling system.
[009] Another object of an embodiment herein is to provide methods for circulating a refrigerant in the vehicular cooling system.
[0010] Another object of an embodiment herein is to provide the refrigerant flow paths which achieve efficient cooling for a battery system of an electric vehicle.
[0011] Another object of an embodiment herein is to provide the refrigerant flow paths which achieve efficient cooling for an automobile engine.
[0012] Another object of an embodiment herein is to provide the refrigerant flow paths which achieve effective heat exchange between a coolant and a refrigerant in the vehicular cooling system.
[0013] Another object of an embodiment herein is to provide the refrigerant flow paths having at least one internal heat exchanger for effective cooling of the battery system of the electric vehicle.
[0014] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0015] The embodiments of the invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0016] Fig. 1 depicts a schematic diagram of a conventional battery cooling architecture;
[0017] Fig. 2 depicts a schematic diagram of a refrigerant flow path for a vehicular cooling system, according to first embodiment as disclosed herein;
[0018] Fig. 3 depicts a schematic diagram of the refrigerant flow path for the vehicular cooling system, according to second embodiment as disclosed herein;
[0019] Fig. 4 depicts a flowchart of a method for circulating the refrigerant in the vehicular cooling system, according to first embodiment as disclosed herein; and
[0020] Fig. 5 depicts a flowchart of another method for circulating the refrigerant in the vehicular cooling system, according to second embodiment as disclosed herein.

DETAILED DESCRIPTION
[0021] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0022] The embodiments herein achieve refrigerant flow paths for circulating a refrigerant in a vehicular cooling system. Further, the embodiments herein achieve methods for circulating a refrigerant in the vehicular cooling system. Furthermore, the embodiments herein achieve the refrigerant flow paths which achieve efficient cooling for a battery system of an electric vehicle. Additionally, the embodiments herein achieve the refrigerant flow paths which achieve efficient cooling in an automobile engine. Moreover, the embodiments herein achieve the refrigerant flow paths which achieve effective heat exchange between a coolant and a refrigerant in the vehicular cooling system. Also, the embodiments herein achieve the refrigerant flow paths having at least one internal heat exchanger for effective cooling of the battery system of the electric vehicle. Referring now to the drawings, and more particularly to Fig. 1 through Fig. 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0023] For the purpose of this description and ease of understanding, the refrigerant flow is explained herein below with reference to a cooling system provided in an electric vehicle. However, it is also within the scope of the invention to provide the refrigerant flow path in any other vehicular cooling system such as i.c. engine without otherwise deterring the intended function of the refrigerant flow path as can be deduced from the description and corresponding drawings.
[0024] Fig. 1 depicts a schematic diagram of a conventional battery cooling architecture. The conventional battery cooling architecture includes a battery side cooling loop and a vehicle’s refrigeration loop. The battery side of the conventional battery cooling system comprises of a battery management system and the battery pack along with liquid cooling arrangement. The refrigerant side comprises of a control panel, a HVAC unit, at least one flow control valve for the cabin, a battery chiller, an internal heat exchanger, a compressor, at least two pressure sensors, and a condenser. In conventional vehicular cooling system the refrigerant form the compressor is streamed towards the condenser which is further passed to the heat exchanger and the chiller as shown in fig. 1. Further, the refrigerant from the chiller is passed to the compressor and the refrigerant from the heat exchanger is streamed to the HVAC unit which is further transferred to the compressor through the heat exchanger as shown in Fig. 1.
[0025] Fig. 2 depicts a schematic diagram of a refrigerant flow path for a vehicular cooling system, according to first embodiment as disclosed herein. According to first embodiment, the refrigerant flow path (100) includes a control panel (102), a HVAC unit (104), at least one flow control valve for the cabin (106), a battery chiller (also referred to as chiller in this description) (108), a heat exchanger (110), a compressor (112), at least two pressure sensors (114), and a condenser (116) which are arranged in a predetermined manner to form the vehicle’s refrigeration loop. The embodiments herein provides the refrigerant flow path which includes an integrated heat exchanging unit (also referred to as heat exchanger in this description) (IHX) with the existing cooling models. In an embodiment, the heat exchanger (IHX) (110) is a liquid-to-vapor heat exchanger, with one inner chamber and one outer chamber. A hot liquid refrigerant flows through the outer chamber, and the outer chamber surrounds the inner chamber which receives cool fluid flowing there through. The chiller (108) receives the liquid refrigerant from the heat exchanger outlet (not shown) and the refrigerant is streamed to a thermal expansion valve (TXV) inlet (not shown) to exchange heat with the battery coolant. The advantage of the refrigerant flow path (100) according to the first embodiment includes effective heat exchange between battery coolant and refrigerant, thus reducing a load on the compressor (112) and resulting into lower power consumption from the high voltage battery. In the first embodiment, the refrigeration flow path includes a simple change in a suction line path wherein the coolant from the battery chiller is directed towards the HVAC unit and not to the compressor on the refrigerant side.
[0026] In an embodiment, the chiller (108) is a compact plate-to-plate heat exchanger that transfers thermal energy from the battery coolant loop to the vehicle's refrigerant loop to maintain optimum battery temperatures. In the first embodiment of this invention, once the battery is cooled, a hot coolant from the battery pack is sent towards the battery chiller (108). After the exchange of the heat of coolant with the refrigerant, the cooled battery coolant is circulated back to the battery pack. On the refrigerant side, there is no additional load acting on the compressor unlike the conventional cooling architecture. The refrigerant is transferred towards the heat exchanger (110). As the heat exchanger (110) is a liquid to vapor type exchanger, hot liquid refrigerant flows is made to flow through the outside chamber, which surrounds inner chamber through which the cool fluid flows.
[0027] According to the first embodiment, the refrigerant is streamed from the compressor (112) to the condenser (116) which is further streamed to the heat exchanger (110). From heat exchanger (110) the refrigerant is transferred to the chiller (108) and the HVAC unit (104). The the flow control valve (106) is positioned between the heat exchanger (100) and the HVAC unit (104). Furthermore, the refrigerant from the chiller (108) is further transferred towards an outlet of the HVAC unit (104). The refrigerant from the HVAC unit (104) is further passed to the heat exchanger (110) which is further transferred to the compressor (112). The refrigerant is circulated through the vehicle’s refrigeration loop as shown in Fig. 2. The refrigerant flow path (100) according to the first embodiment provides effective heat exchange between battery coolant and the refrigerant.
[0028] Fig. 3 depicts a schematic diagram of a refrigerant flow path (200) for a vehicular cooling system, according to second embodiment as disclosed herein. According to second embodiment, the refrigerant flow path (200) includes a control panel (202), a HVAC unit (204), at least one flow control valve for the cabin (206), a battery chiller (also referred to as chiller in this description) (208), a first heat exchanger (210), a second heat exchanger (218), a compressor (212), at least two pressure sensors (214), and a condenser (216) which are arranged in a predetermined manner to form the vehicle’s refrigeration loop.
[0029] The second embodiment of this invention includes an additional heat exchanger i.e. the second heat exchanger (218) which is connected to the first heat exchanger (210), the chiller (208) and the compressor (212) of the vehicle’s refrigeration loop. Addition of the second heat exchanger (218) further reduces the load on the compressor by exchanging the heat once again. Hot refrigerant from the condenser (216) enters the first heat exchanger (210) and exchanges heat with the cold refrigerant coming from the evaporator outlet. In the liquid cooled batteries, TXVs provided in the vehicle refrigeration loop reduces the temperature of refrigerant, hence the first and second heat exchangers (210 and 218) integrated with chiller (208) provides more effective battery cooling.
[0030] According to the second embodiment, the refrigerant is streamed from the compressor (212) to the condenser (216) which is further streamed to the first heat exchanger (210). From first heat exchanger (210) the refrigerant is transferred to the chiller (208) and the second heat exchanger (218). The refrigerant from the second heat exchanger (218) flows to the chiller (208) which is further transferred to the compressor (212) through the second heat exchanger (218). Further, the refrigerant which is passed to the HVAC unit (204) through the flow control valve (206) is further transferred to the first heat exchanger (210) which is again transferred to the compressor (112). The refrigerant is circulated through the vehicle’s refrigeration loop as shown in Fig. 3. The refrigerant flow path (200) according to the second embodiment provides more effective heat exchange between battery coolant and the refrigerant.
[0031] Fig. 4 depicts a flowchart of a method for circulating the refrigerant in the vehicular cooling system, according to first embodiment as disclosed herein. The method (300) for circulating the refrigerant in the vehicular cooling system includes allowing flow of said refrigerant from a compressor (112) to a condenser (116) (At step 302). Further, the method (300) includes streaming said refrigerant from said condenser (116) to a heat exchanger (110) (At step 304). Furthermore, the method (300) includes streaming said refrigerant from said heat exchanger (110) to a HVAC unit (104) and a chiller (108) (At step 306). Additionally, the method (300) includes streaming said refrigerant from said chiller (108) towards an outlet of said HVAC unit (104) (At step 308). Moreover, the method (300) includes allowing flow of said refrigerant from said HVAC unit (104) to said heat exchanger (110) (At step 310). Further, the method (300) includes allowing flow of said refrigerant from said heat exchanger (110) to said compressor (112) (At step 312). Also, the method (300) includes circulating said refrigerant through said compressor (112), said condenser (116), said heat exchanger (110), said chiller (108) and said HVAC unit (104) (At step 314).
[0032] Fig. 5 depicts a flowchart of another method for circulating the refrigerant in the vehicular cooling system, according to second embodiment as disclosed herein. The method (400) for circulating the refrigerant includes allowing flow of said refrigerant from a compressor (212) to a condenser (216) (At step 402). Further, the method (400) includes streaming said refrigerant from said condenser (216) to a first heat exchanger (210) (At step 404). Furthermore, the method (400) includes allowing flow of said refrigerant from said first heat exchanger (210) to a HVAC unit (204) and a second heat exchanger (218) (At step 406). Additionally, the method (400) includes streaming said refrigerant from said second heat exchanger (218) to a chiller (208) (At step 408). Moreover, the method (400) includes allowing flow of said refrigerant from said chiller (208) to said compressor (212) through said second heat exchanger (218) (At step 410). Further, the method (400) includes streaming said refrigerant from said HVAC unit (204) to said first heat exchanger (210) (At step 412). Furthermore, the method (400) includes allowing flow of said refrigerant from said first heat exchanger (210) to said compressor (212) (At step 414). Also, the method (400) includes circulating said refrigerant through said compressor (212), said condenser (216), said first heat exchanger (210), said second heat exchanger (218), said chiller (208) and said HVAC unit (204) (At step 416).
[0033] The technical advantages of the internal heat exchanger are as follows. Effective heat exchange between battery coolant and refrigerant. Reduction in compressor load and resulting into lower power consumption from the High Voltage battery.
[0034] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
,CLAIMS:We claim,
1. A method (300) of circulating a refrigerant in a vehicular cooling system, comprising:
allowing flow of said refrigerant from a compressor (112) to a condenser (116);
streaming said refrigerant from said condenser (116) to a heat exchanger (110);
streaming said refrigerant from said heat exchanger (110) to a HVAC unit (104) and a chiller (108);
streaming said refrigerant from said chiller (108) towards an outlet of said HVAC unit (104);
allowing flow of said refrigerant from said HVAC unit (104) to said heat exchanger (110);
allowing flow of said refrigerant from said heat exchanger (110) to said compressor (112); and
circulating said refrigerant through said compressor (112), said condenser (116), said heat exchanger (110), said chiller (108) and said HVAC unit (104).

2. The method (300) as claimed in claim 1, wherein said heat exchanger (110) is at least a liquid-to-vapor heat exchanger, said heat exchanger (110) includes an inner channel (not shown) and an annular outer channel (not shown).

3. The method (300) as claimed in claim 2, wherein said outer channel receives a hot refrigerant fluid and said inner channel receives a cooled refrigerant fluid.

4. The method (300) as claimed in claim 1, wherein said chiller (108) receives said refrigerant from said heat exchanger (110) and streams said refrigerant to a thermal expansion valve inlet (not shown) to exchanges heat with a battery coolant.

5. A method (400) of circulating a refrigerant in a vehicular cooling system, comprising:
allowing flow of said refrigerant from a compressor (212) to a condenser (216);
streaming said refrigerant from said condenser (216) to a first heat exchanger (210);
allowing flow of said refrigerant from said first heat exchanger (210) to a HVAC unit (204) and a second heat exchanger (218);
streaming said refrigerant from said second heat exchanger (218) to a chiller (208);
allowing flow of said refrigerant from said chiller (208) to said compressor (212) through said second heat exchanger (218);
streaming said refrigerant from said HVAC unit (204) to said first heat exchanger (210);
allowing flow of said refrigerant from said first heat exchanger (210) to said compressor (212); and
circulating said refrigerant through said compressor (212), said condenser (216), said first heat exchanger (210), said second heat exchanger (218), said chiller (208) and said HVAC unit (204).

6. The method (400) as claimed in claim 1 and 2, wherein said first heat exchanger (210) and said second heat exchanger (218) are at least a liquid-to-vapor heat exchanger, said first and second heat exchangers (210 and 218) include an inner channel and an annular outer channel.

7. A refrigerant flow path (100) for a vehicular cooling system, said vehicular cooling system having a control panel (102), a HVAC unit (104), a flow control valve for a cabin (106), a chiller (108), a heat exchanger (110), a compressor (112), at least two pressure sensors (114), and a condenser (116), said refrigerant flow path (100) comprising:
said compressor (112) provided in fluid communication with said condenser (116);
said condenser (116) provided in fluid communication with a heat exchanger (110);
said heat exchanger (110) provided in fluid communication with a chiller (108) and a HVAC unit (104);
said chiller (108) provided in fluid communication with an outlet of said HVAC unit (104);
said HVAC unit (104) provided in fluid communication with said heat exchanger (110); and
said heat exchanger (110) provided in fluid communication with said compressor (112),
wherein,
said chiller (108) is configured to transfer thermal energy from a battery coolant loop to a vehicle's refrigerant loop to maintain an optimum battery temperature.

8. The refrigerant flow path (100) for the vehicular cooling system as claimed in claim 7, wherein said chiller (108) is at least a compact plate-to-plate heat exchanger.

9. A refrigerant flow path (200) for a vehicular cooling system, said vehicular cooling system having a control panel (202), a HVAC unit (204), a flow control valve (206) for a cabin, a chiller (208), an internal heat exchanger (210), a compressor (212), at least two pressure sensors (214), and a condenser (216), said refrigerant flow path (200) comprising:
said compressor (212) provided in fluid communication with said condenser (216);
said condenser (216) provided in fluid communication with a first heat exchanger (210);
said first heat exchanger (210) provided in fluid communication with a second heat exchanger (218) and a HVAC unit (204);
said second heat exchanger (218) provided in fluid communication with a chiller (208);
said chiller (208) provided in fluid communication with said compressor (212) through said second heat exchanger (218);
said HVAC unit (204) provided in fluid communication with said first heat exchanger (210); and
said first heat exchanger (210) provided in fluid communication with said compressor (212),
wherein,
said chiller (208) is configured to transfer thermal energy from a battery coolant loop to a vehicle's refrigerant loop to maintain an optimum battery temperature.