FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See section 10 and rule 13]
TITLE: “A SYSTEM FOR REGULATING A CABIN TEMPERATURE OF A VEHICLE AND A METHOD THEREOF”
NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS PASSENGER VEHICLES LIMITED, having address at Floor 3, 4, Plot-18, Nanavati Mahalaya, Mudhana Shetty Marg, BSE, Fort, Mumbai, Mumbai City, Maharashtra, 400001.
Nationality: INDIAN
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD:
Present disclosure generally relates to the field of a heating ventilation and air conditioning (HVAC) system. Particularly, but not exclusively, the present disclosure relates to a system and a method to regulate and maintain a desired temperature inside a passenger cabin of a vehicle.
BACKGROUND OF DISCLOSURE:
A heating, ventilating and air conditioning (HVAC) system is commonly used in all types of commercial and passenger vehicles to provide comfort to passengers in different climatic conditions. The HVAC system is used to maintain thermal indoor air quality. The HVAC system also heats the air along with an air conditioning system of the vehicle. The air is heated using the heat from an engine’s cooling system. Typically, the HVAC system comprises a blower, at least two heat exchangers and an air vent assembly. A first heat exchanger of the at least two heat exchangers is connected with the air conditioning system and a second heat exchanger of the at least two heat exchangers is connected with the engine cooling system. The air conditioning system includes a compressor, a condenser, an expansion valve, and an evaporator operable in a refrigeration cycle to condition air and generate cool air. This cool air is directed into a vehicle cabin via an air vent assembly. Subsequently, the cool air is redirected to the second heat exchanger to heat the air. The heated or warm air is then directed into the vehicle cabin via the air vent assembly having a plurality of flap actuators which control flow of air within ducts of the HVAC system. The plurality of flap actuators allows flow of air into the cabin as per the passenger’s requirement. The temperature of the cabin is selected by the passenger through controls provided on a dashboard of the vehicle and accordingly the HVAC system is operated to provide the cool air or the hot air for delivery into the cabin.
Conventionally, the HVAC systems require at least two fluid flow paths (or) conduits to deliver conditioned air into the cabin at desired temperatures. A first fluid flow path is connected with the air conditioning system and the first heat exchanger to deliver the cool air. A second fluid flow path is connected with the engine cooling system and the second heat exchanger to deliver the cool air. Both the first and second fluid flow paths are connected with the air vent assembly to dispense the air into the vehicle cabin. However, this arrangement of multiple heat exchangers and the at least two fluid flow paths corresponding to each heat exchanger utilizes more space inside the vehicle for accommodating the HVAC system. Further, this limits the design of the cabin without
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having much room inside the vehicle which causes discomfort to the passengers. Additionally, the air vent assembly which regulates the air flow into the cabin also occupies more space within the cabin of the vehicle. Consequently, this makes the overall HVAC system bulky with more components and thereby increases power consumption. Further, the overall weight of the HVAC system also increases which reduces operational efficiency of the system. Also, the components of the HVAC system require frequent maintenance which increases operational and maintenance costs.
The present disclosure is intended to overcome one or more above stated limitations.
SUMMARY OF THE DISCLOSURE:
One or more shortcomings of conventional heating, ventilation, and air conditioning (HVAC) system are overcome, and additional advantages are provided through a system a method of the present disclosure. Additional features and advantages are realized through the arrangement of the components of the system to regulate and supply desired temperature inside a vehicle cabin. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure, a system for regulating a cabin temperature in a vehicle is disclosed. The system comprises a cooling unit configured to generate a cool fluid having a first predetermined temperature. A heating unit is in fluid communication with an engine cooling system of the vehicle. The heating unit configured to receive a fluid from the engine cooling system to generate a hot fluid having a second predetermined temperature. A mixing tank is fluidically coupled to the cooling unit and the heating unit. The mixing tank configured to receive the cool fluid and the hot fluid, to generate and store a mixed fluid having a third predetermined temperature. Further, a heat exchanger in fluid communication with the mixing tank and arranged proximal to the cabin. The heat exchanger receives the mixed fluid and generates a conditioned air having a fourth predetermined temperature and transfer the conditioned air into the cabin. A control unit is communicatively coupled to the heating unit, the cooling unit, and the mixing tank. The control unit is configured to operate the cooling unit and the heating unit to selectively dispense at least

one of the cool fluid and the hot fluid into the mixing tank and obtain the mixed fluid having the third predetermined temperature.
In an embodiment, the system comprises a plurality of sensors connected to the cooling unit, the heating unit, and the mixing tank. The plurality of sensors is configured to determine a temperature of fluid within the cooling unit, the heating unit, and the mixing tank respectively.
In an embodiment, the control unit is communicatively coupled with the plurality of sensors. The control unit is configured to operate the cooling unit and the heating unit based on the determined temperature of fluid by the plurality of sensors.
In an embodiment, the cooling unit comprises a compressor configured to compress a refrigerant to generate vapor. A condenser is fluidically coupled to the compressor, the condenser receives the vapor from the compressor and converts the vapor into a liquid. An expansion valve is fluidically coupled to the condenser. The expansion valve receives the liquid from the condenser and expands the liquid to reduce the temperature of the liquid. A chiller is fluidically coupled to the expansion valve and the compressor. The chiller evaporates the liquid dispensed from the expansion valve to generate the cool fluid having the first predetermined temperature.
In an embodiment, the chiller is fluidically coupled to the mixing tank and the heat exchanger to supply the cool fluid into the at least one of the mixing tank and the heat exchanger.
In an embodiment, the heating unit comprises a heater that is configured to receive an engine coolant from the engine cooling system through a coolant pump. The heater is fluidically coupled to the mixing tank and the heat exchanger to supply the hot fluid into the at least one of the mixing tank and the heat exchanger.
In an embodiment, the system further comprises a first flow control valve disposed between the chiller and the heat exchanger. The first control valve is configured to regulate flow of the cool fluid from the chiller into the heat exchanger.

In an embodiment, the system further comprises a second flow control valve disposed between the heater and the heat exchanger, wherein the second flow control valve is configured to regulate flow of the hot fluid from the heater into the heat exchanger.
In an embodiment, the control unit is coupled to the first and second flow control valves to selectively operate at least one of the first and second flow control valves, to dispense and regulate the fluid flow from the cooling unit and the heating unit into the mixing tank and the heat exchanger respectively.
In an embodiment, the system comprises a blower coupled to the heat exchanger and is configured to dispense an air stream over the heat exchanger for heat transfer between the air stream from the blower and the mixed fluid.
In an embodiment, the plurality of sensors is at least one of a temperature sensor, a pressure sensor, and a flow rate sensor.
In an embodiment, the control unit is configured to actuate the cooling unit, to dispense the cool fluid at the first predetermined temperature into the mixing tank when the third predetermined temperature of the mixed fluid in the mixing tank is above a pre-set temperature.
In an embodiment, the control unit is configured to actuate the heating unit, to dispense the hot fluid at the second predetermined temperature into the mixing tank when the third predetermined temperature of the mixed fluid in the mixing tank is below the pre-set temperature.
In another non-limiting embodiment of the present disclosure, a method of regulating the temperature within a cabin of the vehicle is disclosed. The method comprises the steps of initially determining an ignition ON condition of the vehicle by a control unit. Then, the control unit receives an input from a user corresponding to a pre-set temperature of air within the cabin. Later, a first predetermined temperature of a cool fluid, a second predetermined temperature of a hot fluid a third predetermined temperature of a mixed fluid within a cooling unit, a heating unit and a mixing tank respectively are determined by a plurality of sensors. Followed by comparing the third predetermined temperature of the fluid within the mixing tank with the

preset temperature of the air by the control unit. Further, the control unit operates the cooling unit and the heating unit to selectively dispense at least one of the cool fluid and the hot fluid into the mixing tank and obtain the mixed fluid having the third predetermined temperature. The control unit is communicatively coupled with the plurality of sensors, the heating unit, the cooling unit, and the mixing tank. Lastly, the control unit dispenses the mixed fluid at the third predetermined from the mixing tank over a heat exchanger positioned proximate to the cabin of the vehicle to generate a conditioned air having the preset temperature and supply the conditioned air at the pre-set temperature within the cabin of the vehicle.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following description.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS:
The novel features and characteristics of the disclosure are set forth in the appended description. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:
Fig. 1 is a schematic layout of a system for regulating a cabin temperature of a vehicle, in accordance with an embodiment of the present disclosure.
Fig. 2 is a schematic layout of the system of Fig. 1, depicting a cooling unit in an ON condition with a heating unit in an OFF condition, in accordance with an embodiment of the present disclosure.
Fig. 3 is a schematic layout of the system of Fig. 1, depicting the heating unit in the ON condition with the cooling unit in the OFF condition, in accordance with an embodiment of the present disclosure; and

Fig. 4 is a flowchart depicting a method of regulating a cabin temperature of a vehicle in accordance with an embodiment of the disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DEATAILED DESCRIPTION:
While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify a system and a method for the purpose of regulating or controlling a vehicle cabin temperature. However, such modification should be construed within the scope of the present disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The terms “comprises”, “comprising”, or any other variations thereof used in the present disclosure, are intended to cover a non-exclusive inclusion, such that a system, a method, an apparatus or a device, that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, method, apparatus, or the device. In other words, one or more elements in the system or the apparatus preceded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system, the method, or the apparatus.

In the following description of the embodiments of the disclosure, reference is made to the accompanying figures that form a part hereof, and in which are shown, by way of illustration, specific embodiments in which the present disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present disclosure, and it is to be understood that other embodiments may be utilized and that, changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
Embodiments of the present disclosure discloses a system for regulating a cabin temperature in a vehicle. Conventionally, a heating, ventilation and air conditioning system comprises a blower, at least two heat exchangers and an air vent assembly. One heat exchanger is connected with a refrigeration system and is used exclusively for cooling with the help of a refrigeration cycle. Another heat exchanger is used for heating or providing hot fluid, either from waste heat of engine or coolant heater or from an electrically operated air heater in case of electric vehicles. The desired temperature is maintained by mixing the hot fluid and the cool fluid coming from the corresponding heat exchangers through separate flow paths to generate a mixed fluid. The mixed fluid is then directed into the cabin through an air vent assembly having a plurality of flap actuators for regulating the air flow within the cabin. This construction of the two heat exchangers along with the two separate flow paths requires a lot of space within the cabin of the vehicle. Consequently, this reduces the cabin space inside the vehicle which causes discomfort to the passengers. Additionally, as the HVAC system includes more components, the overall weight of the system increases which reduces operational efficiency of the system. Also, the costs associated with operation and maintenance pf the HVAC systems also increase. Further, a high-pressure drop is observed in the flow lines in such a construction and also the capacity of the blower must be significantly high to provide pressurized air to both the heat exchangers.
In view of the above, a system for regulating a cabin temperature in a vehicle is disclosed. The system comprises a cooling unit configured to generate a cool fluid having a first predetermined temperature. A heating unit is in fluid communication with an engine cooling system of the vehicle. The heating unit is configured to receive a fluid from the engine cooling system to generate a hot fluid having a second predetermined temperature. A mixing tank is fluidically

coupled to the cooling unit and the heating unit. The mixing tank is configured to receive the cool fluid and the hot fluid, to generate and store a mixed fluid having a third predetermined temperature. Further, a heat exchanger in fluid communication with the mixing tank and arranged proximal to the cabin. The heat exchanger is configured to receive the mixed fluid and generate a conditioned air having a fourth predetermined temperature and transfer the conditioned air into the cabin. A control unit is communicatively coupled with the heating unit, the cooling unit, and the mixing tank. The control unit is configured to operate the cooling unit and the heating unit to selectively dispense at least one of the cool fluid and the hot fluid into the mixing tank and obtain the mixed fluid having the third predetermined temperature. The control unit selectively dispenses the mixed fluid over the heat exchanger which is further transferred into the cabin. This configuration of a single heat exchanger makes the system compact and provides more room in the cabin for a driver and a passenger. Further, this also eliminates the need to have a complex air flow actuating system for directing air flow inside the cabin and thereby reduces overall cost of the system.
Referring to Fig.1 which illustrates a schematic layout of the system (100) to regulate and maintain the cabin temperature of the vehicle. The system (100) comprises a cooling unit (200) and a heating unit (101). The cooling unit (200) and the heating unit (101) are disposed in an engine compartment (27) i.e., proximity to an engine of the vehicle. The cooling unit (200) comprises a compressor (212), a condenser (214), an expansion valve (217) and a chiller (216) in fluid communication with each other in a closed circuit. A refrigerant is passed through the closed circuit and the refrigerant undergoes continuous phase change from liquid to a vapor state and back to the liquid state at a room temperature. In an embodiment, the refrigerant may be at least one of freon (R22), R314A, R717 and R744. The compressor (212) is configured to compress the refrigerant to increase the temperature and pressure of the refrigerant and converts into High pressure high temp gas. The condenser (214) is fluidically coupled to the compressor (212) through a plurality of hoses or pipes (not shown in Fugs.). The condenser (214) is further coupled to the chiller (216) and the expansion valve (217) is disposed between the condenser (214) and the chiller (216). The condenser (214) is configured to receive a high temperature and high-pressure gas from the compressor (212). The condenser (214) is configured to cool the refrigerant in the gas form and convert it into a liquid phase. The condenser (214) comprises of

a plurality of tubes or coils (not shown in Figs.) arranged in a twisted configuration to receive the refrigerant. The refrigerant flows through the plurality of tubes and rejects heat to an air surrounding the condenser (214) and thus the refrigerant gets liquefied i.e., converted into the liquid at low temperature. The pressure of the liquid refrigerant exiting the condenser (214) is reduced by the expansion valve (217) by directing the fluid low from the condenser (214) into the chiller (216) at a rate equal to the evaporation rate in the chiller (216). In an embodiment, the chiller (216) comprises an enclosure (not shown in Figs.) and a plurality of tubes arranged within the enclosure. The enclosure is configured to receive and store a fluid having a room temperature from an auxiliary tank (not shown in Figs.). The plurality of tubes is configured to receive the low temperature and pressure liquid refrigerant from the expansion valve (217). The liquid refrigerant gets evaporated in the chiller (216) due to heat transfer between the fluid within the enclosure and the liquid refrigerant flowing or passing inside the plurality of tubes. This provides the cooling effect and a cool fluid having a first predetermined temperature is generated within the chiller (216). As the refrigerant is completely evaporated, subsequently the phase of the refrigerant is changed from the liquid to the vapor form. After evaporation, the vapor refrigerant again enters the compressor (212) to begin a next cycle of the cooling unit (200) and this process continues to continuously provide the cool fluid having the first predetermined temperature at the chiller (216).
The heating unit (101) comprises a coolant pump (104) and a heater (106) is fluidically connected to the coolant pump (104) through a plurality of conduits (not shown in Figs.). The coolant pump (104) is connected to an engine cooling system (not shown in Figs.). The coolant pump (104) is configured to supply a coolant within a plurality of coolant jackets (not shown in figs.) around a cylinder head (not shown in figs.) of an engine (102) to cool the engine (102) of the vehicle. The heater (106) receives the coolant from the coolant pump (104) and is configured to heat the coolant to generate the hot fluid having the second predetermined temperature. In an embodiment, the heat from the engine (102) may be used to heat the coolant. The hot fluid generated by the heater is transferred to a mixing tank (10).
The mixing tank (10) is fluidically coupled to the cooling unit (200) and the heating unit (101). The mixing tank (10) is positioned downstream of the cooling unit (200) and the heating unit (101). The mixing tank (10) comprises a body (not shown in Figs.) and a cover (not shown in

Figs.) to enclose mixing tank (10). In an embodiment, mixing tank (10) may comprise an agitator (not shown in Figs.) positioned at an upper portion of the body for mixing the fluid within mixing tank (10). In an embodiment, the agitator may be driven by a motor (not shown in Figs.) for mixing purpose. At least two inlets (not shown in Figs.) may be defined on opposite surfaces of the body and at least one outlet (not shown in Figs.) is defined on a lower portion of the body. Each of the at least two inlets are connected to the cooling unit (200) and the heating unit (101) respectively. The mixing tank (10) is coupled to the cooling unit (200) through a first fluid flow path (2). The mixing tank (10) is coupled to the heating unit (101) by a second fluid flow path (3). The mixing tank (10) is configured to receive the cool fluid from the cooling unit (200) and the hot fluid from the heating unit (101) and generate a mixed fluid having a third predetermined temperature. The cool fluid from the cooling unit (200) and the hot fluid from the heating unit (101) is transferred into the mixing tank (10) through a pumping unit (108, 218).
The pumping unit (108, 218) comprises a first pump (218) arranged in the first fluid flow path (2). The first pump (218) is configured to transfer the cool fluid having the first predetermined temperature from the chiller (216) into the mixing tank (10). A second pump (108) is arranged in the second fluid flow path (3). The second pump (108) is configured to transfer the hot fluid having the second predetermined temperature from the heater (106) into the mixing tank (10). Further an auxiliary pump (20) is fluidically connected to the at least one outlet of the mixing tank (10). The auxiliary pump (20) is configured to transfer the mixed fluid having the third predetermined temperature from the mixing tank (10) to an air circulation unit (400).
A plurality of sensors (not shown in Figs.) is connected to the cooling unit (200), the heating unit (101) and the mixing tank (10). At least one first sensor (not shown in Figs.) is connected to the chiller (216) and is configured to determine the first predetermined temperature of the cool fluid within the chiller (200) of the cooling unit (200). At least one second sensor (not shown in Figs.) is connected with the heater (106) and is configured to determine the second predetermined temperature of the hot fluid present in the heating unit (101). At least one third sensor (not shown in Figs.) is connected with the mixing tank (10) to determine the third predetermined temperature of the mixed fluid present in the mixing tank (10). In an

embodiment, the plurality of sensors may be at least one of at least one of a temperature sensor, a pressure sensor, and a flow rate sensor.
The system (100) further comprises a heat exchanger (24). The heat exchanger (24) is disposed in a cabin compartment (28) i.e., proximal to the cabin which is inside a firewall (26) of the vehicle. The firewall (26) divides the engine compartment (27) and the cabin compartment (28) of the vehicle and reduces noise of the engine transmitting to the cabin. The heat exchanger (24) is structured with a plurality of tubes (not shown in Figs.) for fluid flow therewithin. In an embodiment, a cooling fan (not shown in Figs.) may be disposed over the plurality of tubes to increase a rate of heat exchange. In an embodiment, the heat exchanger (24) may be structured in a form of a water tube heat exchanger (24), that includes a shell and tube type heat exchangers, or in other cases it may also be a tube-in-tube heat exchangers etc., based on the requirement. The heat exchanger (24) is configured to receive the mixed fluid having the third predetermined temperature from the mixing tank (10) via. the auxiliary pump (20). Further, a third fluid flow path (4) connected to the heat exchanger (24) and the chiller (216) of the cooling unit (200). A fourth fluid flow path (5) is provided to connect the heat exchanger (24) with the heater of the heating unit (101).
A blower (22) is positioned in the cabin compartment (28) and is thermally coupled to the heat exchanger (24). The blower (22) comprises a housing (not shown in Figs.) and an impeller (not shown in Figs.) mounted within the housing. An inlet (not shown in Figs.) is provided to receive external air or air from the cabin and an outlet (not shown in Figs.) is defined to deliver the air with high pressure. A motor (not shown in Figs.) is connected to the blower (22) and is configured to rotate the impeller. Upon actuation of the motor, the impeller rotates to suck the air inside the cabin of the vehicle and delivers the air at high pressure over the heat exchanger (24) with an increased velocity. The air from the outlet of the blower (22) exchanges heat with the mixed fluid flowing through the plurality of tubes of the heat exchanger (24) that is received from the mixing tank (10) to obtain a conditioned air having a preset temperature. This conditioned air having the preset temperature is then redirected into the cabin of the vehicle by the heat exchanger (24). In an embodiment, the temperature of the conditioned air dispensed from the heat exchanger (22) corresponds to an input given by the user with respect to the preset cabin temperature which may be selected by the user. After obtaining the pre-set cabin

temperature within the cabin, the remaining hot fluid from the heat exchanger (24) after the heat transfer is transferred simultaneously to the cooling unit (200) and the heating unit (101) through the third and fourth fluid flow paths (4, 5) respectively. Further, a first flow control valve (215) is arranged on the third fluid flow path (4) to regulate the flow of the cool fluid from the chiller (216) into the heat exchanger (24). A second flow control valve (115) is arranged on the fourth fluid flow path (4) to regulate the flow of the cool fluid from the heater (106) into the heat exchanger (24). In an embodiment, the first and the second control valves (215, 115) may be at least one of a solenoid valve, a gate valve, a plug valve, and a non-return valve.
The system (100) further comprises a control unit (300). In an embodiment, the control unit (300) may be an electronic control unit (ECU) of the vehicle. The control unit (300) is communicatively coupled with the plurality of sensors. The control unit (300) is also in communication with a control panel (not shown in Figs.) provided on the cabin of the vehicle. In an embodiment, the user may operate the control panel to input the pre-set or desired temperature value within the cabin of the vehicle. The control unit (300) is configured to receive a first signal from the control panel corresponding to the pre-set temperature. The control unit (300) is also configured to receive a second signal from the plurality of sensors corresponding to the temperature of the fluid within the heating unit (101), the cooling unit (200) and the mixing tank (10). The plurality of sensors generates the second signal which corresponds to the temperature of fluid within the cooling unit (200) and the heating unit (101). In other words, the plurality of sensors determines the first predetermined temperature, the second predetermined temperature and the third predetermined temperature in the chiller (216), the heater (106) and the mixing tank (10) respectively and sends out the first signal to the control unit (300). The control unit (300) is configured to operate the cooling unit (200) and the heating unit (101) to selectively dispense at least one of the cool fluid and the hot fluid into the mixing tank (10) and obtain the mixed fluid in the mixing tank (10) having the third predetermined temperature.
Present disclosure also discloses a method of regulating the cabin temperature of the vehicle in three operating conditions. Referring to Fig. 2, the method of operating the system (100) to supply cool fluid to the cabin of the vehicle is disclosed. This condition may also be referred to as a full cold or chilled condition. The method (500) comprises of initially receiving the first

signal by the control unit (300) from the control panel corresponding to the preset temperature of the cabin selected by the user. In an embodiment, the preset temperature may correspond to a lower temperature. In an embodiment, the preset temperature may be less than 20℃. Later, the control unit (300) determines the first predetermined temperature of the cooling unit (200) and the third predetermined temperature of the mixed fluid within the mixing tank (10) based on the second signal received by the plurality of sensors. Later, if the third determined temperature of the mixed fluid is more than the preset temperature selected by the user, the control unit (300) deactivates the heating unit (101) and turns ON the cooling unit (200) to dispense the cool fluid from the chiller (216) of the cooling unit (200) into the mixing tank (10). The cool fluid gets accumulated in the mixing tank (10) until the third predetermined temperature is obtained and the same is then transferred to the heat exchanger (24) via the auxiliary pump (20). The cool fluid is subjected to heat transfer with the high-pressure air from the blower (22) to obtain the cool fluid having the preset temperature. The cool fluid is then transferred into the cabin of the vehicle to provide maximum cooling to the user. Further, the control unit (300) closes the second flow control valve (5) to restrict the flow of remaining air exiting the heat exchanger (24) to the heating unit (101). Simultaneously, the control unit (300) opens the first flow control valve (4) to allow the flow of the fluid only to the cooling unit (200). This process is continued such that the cooling unit (200) continuously dispenses the cool fluid to maintain the third predetermined temperature into the mixing tank (10) for maximum cooling within the cabin of the vehicle.
Now referring to Fig. 3, the method of operating the system to supply hot fluid having the second predetermined temperature to the cabin of the vehicle is disclosed. The method (500) comprises of initially receiving the first signal by the control unit (300) from the control panel corresponding to the preset temperature selected by the user. In an embodiment, the preset temperature may be more than 20℃. Further, the control unit (300) determines the second predetermined temperature of the heating unit (101) and the third predetermined temperature of the mixed fluid within the mixing tank (10) based on the second signal received from the plurality of sensors. Later, if the determined temperature of the mixed fluid is less than the temperature selected by the user, the control unit (300) deactivates the cooling unit (200) and turns ON the heating unit (101) to dispense the hot fluid from the heater (106) of the heating

unit (101) into the mixing tank (10). The hot fluid accumulated in the mixing tank (10) is then transferred to the heat exchanger (24) via the pump (20). The hot fluid in the heat exchanger (24) exchanges heat with the high-pressure air from the blower (22) to generate the hot fluid having the preset temperature. The hot fluid is then transferred into the cabin of the vehicle to provide maximum heating to the user. Further, the control unit (300) closes the first flow control valve (4) to restrict the flow of remaining fluid exiting the heat exchanger (24) to the cooling unit (200). Simultaneously the control unit (300) opens the second flow control valve (5) to allow the flow of the fluid only to the heating unit (101). This process is continued, and the heating unit (101) continuously dispenses the hot fluid into the mixing tank (10) to maintain the maximum heat within the cabin of the vehicle.
Now referring back to Fig. 1, the method of providing mixed or optimum temperature to the cabin of the vehicle is disclosed. In the mixed condition, the control unit (300) maintains the temperature of the mixed fluid in the mixing tank (10) at the third predetermined temperature. In this condition, the control unit (300) operates the pumping unit (108, 218) connected to the heating unit (101) and the cooling unit (200) at varying speeds such that the third predetermined temperature is maintained in the mixing tank (10). The control unit (300) activates both the heating unit (101) and the cooling unit (200) to provide the mixed fluid at the third predetermined temperature in the mixing tank (10) to redirect the same into the cabin of the vehicle through the heat exchanger (24) as per the requirement of the user.
Referring to Fig. 4, a method (500) of regulating the cabin temperature is disclosed. The method comprises of initially determining an ignition ON condition of the vehicle at step 501. After determining the ON condition of the vehicle, at step 502, the control unit (300) receives an input from the user corresponding to the preset temperature of air within the cabin (or) cabin temperature. Later, at step 503, the plurality of sensors determines the cabin temperature of the vehicle. The plurality of sensors transmits the first signal to the control unit (300) upon determining the cabin temperature. At step 504, the plurality of sensors determines the first, second and third predetermined temperatures of the fluid present in the cooling unit (200), heating unit (101) and the mixing tank (10). The plurality of sensors transmits a second signal to the control unit (300) corresponding to the first, second and third predetermined temperatures. Further, at step 505, the control unit (300) compares the third predetermined temperature within

the mixing tank (10) with the preset temperature. At step 506, the control unit (300) and operates the cooling unit (200) and the heating unit (101) accordingly to selectively dispense at least one of the cool fluids and the hot fluid into the mixing tank and obtain the mixed fluid having the third predetermined temperature. Lastly, at step 507, the mixed fluid at the third predetermined temperature is directed over the heat exchanger (24) to generate the conditioned air and dispense the same into the cabin of the vehicle. In an embodiment, the mixed fluid is directed over the heat exchanger (24) to generate the preset temperature of the cabin. In other words, if the third predetermined temperature of the mixed fluid determined by the control unit (300) is more than the preset temperature, the control unit (300) will activate the cooling unit (200) to supply the cool fluid into the mixing tank (10) until the third predetermined temperature is reached within the mixing tank (10). Alternatively, if the third predetermined temperature of the mixed fluid is less than the preset temperature, the control unit (300) will activate the heating unit (101) to supply the hot fluid into the mixing tank (10) to obtain the fluid having the third predetermined temperature. In an embodiment, the control unit (300) is communicatively coupled to the first and the second flow control valves (4, 5) to control the fluid flow from the heat exchanger (24) to either the cooling unit (200) or to the heating unit (101) based on the requirement.
In an embodiment, the fluid within the cooling unit (200), the heating unit (101) and the mixing tank (10) is water. However, this cannot be considered as limiting and the fluids such as ethanol or any organic compounds in a state of liquid may be used based on the requirement.
In an embodiment, the first, second and the third predetermined temperatures of the fluid depend on the type of the vehicle and the capacity of the cooling unit (200) and the heating unit (101).
In an embodiment, the first and the second fluid flow paths (2, 3) are made of suitable heat resistant material to withstand higher temperatures of the fluid flowing from the heating unit (101).
The system (100) of the present disclosure uses a single heat exchanger (24) to regulate and maintain the preset temperature within the cabin of the vehicle. Advantageously this makes the system simple and reliable irrespective of different climatic conditions.

The system (100) of the present discloses includes the first and the second fluid paths (2, 3) disposed closer to each other, thereby requiring minimum space to install the system (100). This makes the system (100) compact and takes less time to install in the vehicle.
The system (100) of the present disclosure can be installed in a variety of vehicles which require the HVAC system to maintain optimum temperature inside the cabin of the vehicle.
The system (100) of the present disclosure includes a lesser number of components. This reduces manufacturing and maintenance costs of the system (100).
The system (100) of the present disclosure eliminates the need of using actuators and an air vent assembly to regulate the air within the cabin of the vehicle. Advantageously this enables to design the system (100) in a minimum space and in a sleek configuration.
EQUIVALENTS
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.
Reference numerals:

Part Numeral
System 100
Heating unit 101
Cooling unit 200
Electronic control unit (ECU) 300

First fluid line 2
Second fluid line 3
Third fluid line 4
Fourth fluid line 5
Mixing tank 10
pump 20
Blower 22
Heat exchanger 24
Firewall 26
Engine compartment 27
Cabin compartment 28
Engine 102
Coolant pump 104
Heater 106
Pumping unit 108, 218
Compressor 212
Condenser 214
Evaporator 216
First flow control valve 215
Second flow control valve 115

We claim:
1. A system (100) for regulating a cabin temperature in a vehicle, the system (100)
comprising:
a cooling unit (200) configured to generate a cool fluid having a first predetermined temperature;
a heating unit (101) in fluid communication with an engine cooling system of the vehicle, the heating unit (101) is configured to receive a fluid from the engine cooling system to generate a hot fluid having a second predetermined temperature;
a mixing tank (10) fluidically coupled to the cooling unit (200) and the heating unit (101), wherein the mixing tank (10) is configured to receive the cool fluid and the hot fluid, to generate and store a mixed fluid having a third predetermined temperature;
a heat exchanger (24) in fluid communication with the mixing tank (10) and arranged proximal to the cabin, wherein the heat exchanger (24) is configured to receive the mixed fluid and generate a conditioned air having a fourth predetermined temperature and transfer the conditioned air into the cabin; and
a control unit (300) communicatively coupled with the heating unit (101), the cooling unit (200) and the mixing tank (10),
wherein the control unit (300) is configured to operate the cooling unit
(200) and the heating unit (101) to selectively dispense at least one of the cool
fluid and the hot fluid into the mixing tank (10) and obtain the mixed fluid having
the third predetermined temperature.
2. The system (100) as claimed in claim 1, comprises a plurality of sensors connected to the cooling unit (200), the heating unit (101) and the mixing tank (10), wherein the plurality of sensors are configured to determine a temperature of fluid within the cooling unit (200), the heating unit (101) and the mixing tank (10).
3. The system (100) as claimed in claim 2, wherein the control unit (300) communicatively coupled with the plurality of sensors, the control unit (300) is configured to operate the cooling unit (200) and the heating unit (101) based on the determined temperature of fluid by the plurality of sensors.

4. The system (100) as claimed in claim 1, wherein the cooling unit (200) comprises:
a compressor (212) configured to compress a refrigerant to generate vapor;
a condenser (214) fluidically coupled to the compressor, the condenser is configured to receive the vapor from the compressor (212) and convert the vapor into a liquid;
an expansion valve (217) fluidically coupled to the condenser (214), the expansion valve (217) is configured to receive the liquid from the condenser (214) and expand the liquid to reduce the temperature of the liquid;
a chiller (216) fluidically coupled to the expansion valve (217) and the compressor (212), the chiller (216) is configured to evaporate the liquid dispensed from the expansion valve to generate the cool fluid having the first predetermined temperature.
5. The system (100) as claimed in claim 4, wherein the chiller (216) is fluidically coupled to the mixing tank (10) and the heat exchanger (24) to supply the cool fluid into the at least one of the mixing tank (10) and the heat exchanger (24).
6. The system (100) as claimed in claim 1, wherein the heating unit (101) comprises a heater (106) configured to receive an engine coolant from the engine cooling system through a coolant pump (104).
7. The system (100) as claimed in claim 6, wherein the heater (106) is fluidically coupled to the mixing tank (10) and the heat exchanger (24) to supply the hot fluid into the at least one of the mixing tank (10) and the heat exchanger (24).
8. The system (100) as claimed in claim 5, comprises a first flow control valve (215) disposed between the chiller (216) and the heat exchanger (24), wherein the first control valve (215) is configured to regulate flow of the cool fluid from the chiller (216) into the heat exchanger (24).
9. The system (100) as claimed in claim 7, comprises a second flow control valve (115)
disposed between the heater (106) and the heat exchanger (24), wherein the second flow

control valve is configured to regulate flow of the hot fluid from the heater (106) into the heat exchanger (24).
10. The system (100) as claimed in claim 3, wherein the control unit (300) is coupled to the first and second flow control valves (215, 115) to selectively operate at least one of the first and second flow control valves (215, 115) to dispense and regulate the fluid flow from the cooling unit (200) and the heating unit (101) into the mixing tank (10) and the heat exchanger (24) respectively.
11. The system (100) as claimed in claim 1, comprises a blower (22) coupled to the heat exchanger (24), wherein the blower (22) is configured to dispense an air stream over the heat exchanger (24) for heat transfer between the air stream from the blower (22) and the mixed fluid.
12. The system (100) as claimed in claim 2, wherein the plurality of sensors is at least one of a temperature sensor, a pressure sensor, and a flow rate sensor.
13. The system (100) as claimed in claim 1, wherein the control unit (300) is configured to actuate the cooling unit (200), to dispense the cool fluid at the first predetermined temperature into the mixing tank (10) when the third predetermined temperature of the mixed fluid in the mixing tank (10) is above a pre-set temperature.
14. The system (100) as claimed in claim 1, wherein the control unit (300) is configured to actuate the heating unit (101), to dispense the hot fluid at the second predetermined temperature into the mixing tank (10) when the third predetermined temperature of the mixed fluid in the mixing tank (10) is below the pre-set temperature.
15. A method (500) of regulating a cabin temperature in a vehicle, the method (500) comprising:
determining, by a control unit (300), an ignition ON condition of the vehicle; receiving by the control unit (300), an input from a user corresponding to a pre¬set temperature of air within the cabin;

determining, by a plurality of sensors, a first predetermined temperature of a cool fluid, a second predetermined temperature of a hot fluid and a third predetermined temperature of a mixed fluid within a cooling unit (200), a heating unit (101) and a mixing tank (10) respectively;
comparing, by the control unit (300), the third predetermined temperature of the mixed fluid within the mixing tank (10) with the preset temperature of the air; wherein the control unit (300) is communicatively coupled with the plurality of sensors;
operating, by the control unit, the cooling unit (200) and the heating unit (101) to selectively dispense at least one of the cool fluid and the hot fluid into the mixing tank (10) and obtain the mixed fluid having the third predetermined temperature, wherein the control unit (300) is communicatively coupled with the heating unit (101), cooling unit (200) and the mixing tank (10); and
dispensing, by the control unit (300), the mixed fluid at the third predetermined from the mixing tank (10) over a heat exchanger (24) positioned proximate to the cabin of the vehicle to generate a conditioned air having the preset temperature and supply the conditioned air at the pre-set temperature within the cabin of the vehicle.
16. The method (500) as claimed in claim 15, wherein the control unit (300) is configured to actuate the cooling unit (200), to dispense the cool fluid at the first predetermined temperature into the mixing tank (10) when the third predetermined temperature of the mixed fluid in the mixing tank (10) is above a pre-set temperature.
17. The method (500) as claimed in claim 15, wherein the control unit (300) is configured to actuate the heating unit (101), to dispense the hot fluid at the second predetermined temperature into the mixing tank (10) when the third predetermined temperature of the mixed fluid in the mixing tank (10) is below the pre-set temperature.