DESC:TECHNICAL FIELD
The present disclosure generally relates to a field of automobile engineering. Particularly, but not exclusively, the present disclosure relates to air conditioning system of vehicle. Further, embodiments of the disclosure disclose a multi-point cooling system for the vehicle.

BACKGROUND
Typical automotive air-conditioning systems use direct expansion type air-conditioners which make use of evaporator, compressor, condenser and expansion valve units to condition the cabin air to comfort levels of the occupants. In such air-conditioners, the refrigerant absorbs heat and evaporates with increase in values of temperature and at constant or slightly increased pressure). More particularly, the refrigerant in liquid phase absorbs heat and evaporates to its vapour state (undergoes a phase change) to form a high temperature and same or slightly elevated pressure vapour refrigerant. The vapour refrigerant is routed into a compressor where it gets compressed to still higher values of temperature and pressure. The refrigerant is then passed through the condenser where it loses latent heat to surroundings and condenses back into liquid phase. The condensed refrigerant throttled or metered into expansion valve expands to low temperature low pressure liquid refrigerant, which is then routed into the evaporator to repeat the cycle. A major requirement in these vapour compression type air conditioning systems is the necessity of more quantity of refrigerant through automotive cabin body to achieve optimum cooling levels. Requirement of more quantity of refrigerant indicates longer time to achieve optimum cooling characteristics inside the cabin. In addition, an increased flow rate of refrigerant under pressure gives rise to potential hazards such as leakage inside the lines, fluctuations in thermal conductivity and thermal inertial values of the refrigerant, and so on. Another inherent drawback of the conventional direct expansion type air conditioner is that the compressors of these air conditioners can either be switched off, or can be switched on i.e. compressor output cannot be varied to suit changing temperatures inside vehicle cabin. Hence, variable cooling requirements depending on varying atmospheric conditions cannot be met using these air-conditioning systems. A limitation of reduced performance of compressor owing to fluctuation in thermal inertia values of the refrigerant (or coolant) is also inherently associated with these systems.

Further, in conventional direct expansion type air-conditioners, if cooling has to be extended to rear of the automotive compartment, the system has to incorporate a separate evaporator unit at the rear portion. This makes the system less compact, and demands additional fluid low lines and valves for circulation of refrigerant. The presence of additional evaporator and installation of additional Refrigerant lines and valves also increase overall cost of installation of the air-conditioning system and cost of operation of the components associated with the air conditioning system. In conventional vehicles, the conditioned air is circulated to other portions of the vehicle cabin such as rear seat compartment using air ducts. In such vehicles, additional blowers are provided in the air ducts to suck the air from front conduit. This increases the number of components in air condition system, which inherently leads to other problems such as increased power consumption, assembly and the like. The provision of additional refrigerant pipe lines running from front unit to rear compartment of the vehicle also leads to hazards such as leakage of refrigerant due to more no. of joints and bends

Furthermore, the conventional direct expansion type air conditioning systems have inherent drawbacks such as limited compressor output which makes the compressor less feasible during long periods of hot soaks. This is because, during hot soaks, quantity of refrigerant required to provide optimum cooling characteristics inside the vehicle cabin will be more, and flow rate of the refrigerant through flow lines has to be increased. This handling of additional quantity of refrigerant and increasing the flow rate of refrigerant will give rise to the need for installing more flow regulating devices such as valves, and makes the refrigeration system complex and bulky.

In light of foregoing discussion, there is a need to develop an improved air-conditioning system which provides multi-point cooling in the vehicle to overcome one or more limitations stated above.

SUMMARY OF THE DISCLOSURE
One or more drawbacks of conventional air-conditioning systems of the vehicles as described in the prior art are overcome, and additional advantages are provided through the system as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, there is provided a multi-point cooling system for a vehicle, the system comprising a refrigeration loop configured to facilitate flow of a refrigerant. The refrigeration loop comprises a heat exchanger for vaporising the refrigerant, a variable displacement compressor connected to the heat exchanger for compressing vapours of the refrigerant, a condenser connected to the variable displacement compressor for condensing vapours of the refrigerant into liquid refrigerant, and an expansion valve connected to the condenser for expanding the liquid refrigerant supplied to evaporator. The multi-point cooling system further comprises a primary cooling loop which is configured to facilitate flow of a cooling solution, the primary cooling loop comprising at least one reservoir to store the cooling solution. The primary cooling loop comprises at least one first pump connected to the least one reservoir for circulating the cooling solution. The cooling solution exchanges heat with the refrigerant in the refrigeration loop through the heat exchanger. At least one first blower is provisioned in the primary cooling loop, the at least one first blower is configured to deliver conditioned air to a first portion of the vehicle cabin. Further, at least one secondary cooling loop is in fluid communication with the at least one reservoir, the at least one secondary cooling loop is configured to cool a second portion of the vehicle cabin. Also, at least one control valve is provisioned at outlet of the reservoir, the at least one control valve is configured to control the flow of cooling solution from the reservoir to the primary cooling loop and the at least one secondary cooling loop. The system also comprises a control unit which is interfaced with the variable displacement compressor and the control valve. The control unit is configured to regulate output of the variable displacement compressor based on temperature of cooling solution at exit of the heat exchanger. Further, control unit is configured to regulate the flow of cooling solution from the reservoir to the primary cooling loop and the at least one secondary cooling loop for a predetermined period based on temperature of the vehicle cabin.

In an embodiment of the present disclosure, the heat exchanger is a counter-flow heat exchanger.

In an embodiment of the present disclosure, the control unit regulates output of the variable displacement compressor depending on accelerator pedal position.

In an embodiment of the present disclosure, the first portion of the vehicle cabin is front portion of the passenger compartment and the second portion of the vehicle cabin is at least one of rear portion of the passenger compartment, refrigeration unit in passenger cabin, bottle holder and cup holder.

In an embodiment of the present disclosure, the at least one secondary loop comprises at least one second pump for circulating the cooling solution and at least one second blower to deliver conditioned air to the second portion of the vehicle cabin.

In an embodiment of the present disclosure, the cooling solution is an ethylene glycol plus water solution comprising additives and the additives are nano-particles.

In an embodiment of the present disclosure, the at least one first pump is a variable displacement pump and is interfaced with the control unit. The control unit is configured to regulate the flow of the cooling solution through the at least one first pump based on temperature in the vehicle cabin.

In an embodiment of the present disclosure, the control unit is configured to cut-off flow from the control valve to the secondary loop till the temperature of the vehicle cabin reaches below a predetermined value.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

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 detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
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 detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

FIG. 1 illustrates schematic representation of a multi-point cooling system for a vehicle, according to an embodiment of the present disclosure.

FIG. 2 illustrates a flowchart showing various opening conditions of the control valve of the multi-point cooling system, according to an embodiment of the present disclosure.

FIG. 3 illustrates a flowchart depicting control logic of the control unit to operate variable displacement compressor, according to an embodiment of the present 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.

DETAILED DESCRIPTION
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its system and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

Use of terms such as “comprises”, “comprising”, or any other variations thereof in the description, are intended to cover a non-exclusive inclusion, such that a setup system, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a mechanism proceeded by “comprising… a” does not, without more constraints, preclude the existence of other elements or additional elements in the mechanism.
To overcome one or more limitations stated in the background, the present disclosure provides a multi-point cooling system provided in vehicle air conditioning unit. An air conditioning unit, as is well known, is used to condition the air in the vehicle cabin (more particularly the passenger compartment) at comfort levels of the occupants. The multi-point cooling system according to the present disclosure, comprises a refrigeration loop which is configured to allow flow of a refrigerant in liquid and vapour phases. The refrigerant undergoes various physical changes (phase changes) during the flow in the refrigeration loop, and is concerned with extraction of heat from the cabin or compartment to be cooled and rejection of extracted heat to the surroundings. The refrigeration loop through which the refrigerant is passed comprises a heat exchanger unit in which liquid refrigerant absorbs heat and vaporizes. The vapours of refrigerant are then routed into a variable displacement compressor connected to the heat exchanger through pipes. The variable displacement compressor compresses vapour refrigerant to elevated temperature and pressure. The high temperature and high pressure vapour refrigerant is then passed into a condenser which is connected to the variable displacement compressor through pipes. The vapour refrigerant which is at a temperature greater than the atmospheric temperature loses latent heat to atmosphere and condenses back into liquid. The liquid refrigerant so formed will be at low temperature and pressure. The low temperature and low pressure refrigerant is then routed into an expansion unit where it is allowed to expand, resulting in a further decrease of temperature and pressure. The expanded liquid refrigerant at low temperature and low pressure is again passed through the heat exchanger unit to repeat the above described cycle. The condenser is fluidly connected to the expansion unit, and the heat exchanger is fluidly connected to the expansion unit. Since the heat exchanger, compressor, condenser and expansion unit are fluidly connected to form refrigeration loop, the absorption and rejection of heat by the refrigerant, i.e. the refrigeration process, takes place in a cyclic manner.

The multi-point cooling system of the present disclosure further comprises a primary cooling loop which is configured to allow flow of a cooling solution. The primary cooling loop communicates with the refrigeration loop through the heat exchanger. More particularly, the heat exchanger allows flow of refrigerant of the refrigeration loop as well as flow of cooling solution of primary loop through it. The cooling solution loses heat to the refrigerant in the heat exchanger and cools down. The refrigerant which absorbs heat from the cooling solution inside the heat exchanger undergoes phase change to form vapour refrigerant. The rest of the refrigeration cycle takes place as described in the above paragraphs. The cooling solution, therefore, continuously extracts heat from the space to be cooled and rejects the heat to the refrigerant. Thus, primary loop of the multi-point cooling system can be regarded as an auxiliary loop or an extension of basic refrigeration cycle.

The primary loop of the multi-point cooling system comprises at least one reservoir which stores the cooling solution. The reservoir stores required quantity of cooling solution for circulating through the primary loop. The circulation of cooling solution through the primary loop is accomplished by at least one first pump which is fluidly connected to the reservoir. The cooling solution delivered by the pump is then passed through a first blower where air is conditioned and delivered to a first portion of the vehicle cabin, such as front portion of the passenger compartment. The conditioned air so delivered into the first portion maintains the temperature of the first portion at comfort levels.

The multi-point cooling system of present disclosure also comprises one or more secondary cooling loop in fluid communication with the at least one reservoir of the primary cooling loop. The one or more secondary cooling loop is configured to cool a second portion of the vehicle cabin, which includes rear portion of passenger compartment, bottle holder, refrigeration unit and cup holder. The secondary loop uses the same very cooling solution which is stored in the reservoir. The circulation of cooling solution in the secondary loop is accomplished by a second pump fluidly connected to the reservoir. A second blower which is fluidly connected to the second pump is provided in secondary loop, and is configured to condition air in the vicinity of second portion of vehicle cabin to optimum cooling conditions. The cooling solution which is circulated through the primary cooling loop and secondary cooling loop is a glycol based solution mixed with water, according to an embodiment of the present disclosure. The cooling solution is also added with nano-particles comprising ions such as metallic and non-metallic ions to increase thermal characteristics of the cooling solution. The increase in thermal characteristics in turn enhances heat transfer ability of the cooling solution with the refrigerant across the heat exchanger, as well as with the air inside the vehicle cabin that is conditioned.

The reservoir in common fluid communication with the primary cooling loop and the one or more secondary cooling loops is provisioned with a control valve to control flow of cooling solution. The control valve selectively permits flow of cooling solution through the secondary cooling loop depending on the cabin temperature and atmospheric temperature conditions. Further, the multi-point cooling system comprises a control unit interfaced with the variable displacement compressor and the control valve. The control unit regulates output of the variable displacement compressor to maintain passenger compartment temperature to comfort levels, whenever fluctuations in atmospheric temperature are observed. The control unit also takes inputs from accelerator pedal position of the vehicle to vary the compressor displacement, thereby optimizing compressor load on the engine. In addition, the control unit takes cooling solution temperature at exit of the heat exchanger as input, and regulates the compressor displacement. This prevents freezing of cooling solution during its flow through the primary cooling loop and the secondary cooling loop. Further, the control unit regulates the flow characteristics of the cooling solution through the primary and secondary loops for predetermined time period based on vehicle cabin temperature. The flow of cooling solution from the reservoir into the secondary cooling loop is also regulated by the control unit. The flow of cooling solution from the control valve into the secondary loop is cut-off by the control unit till the temperature of the vehicle cabin comes below a predetermined value. This helps in reducing the time of cooling the vehicle cabin during hot soak conditions which improves the comfort level of the occupants in the vehicle cabin.

Reference will now be made to a multi-point cooling system for a vehicle, and is explained with the help of figures. The figures are for the purpose of illustration only and should not be construed as limitations on the system. Wherever possible, referral numerals will be used to refer to the same or like parts. It is to be noted that neither the vehicle, nor the assembly of air-conditioner is illustrated in the present disclosure for the purpose of simplicity. One may appreciate that the constructional features of air-conditioners with multi-point cooling loops are considered to be part of the present disclosure.

FIG. 1 is an exemplary embodiment of the present disclosure which illustrates schematic representation of a multi-point cooling system (100) for a vehicle. The multi-point cooling system (100) is an air-conditioning system with a refrigeration loop (25), a primary cooling loop (35) and at least one secondary cooling loop (45). The multi-point cooling system (100) and is intended to condition air at multiple points inside the vehicle cabin, such as but not limited to automotive and locomotive cabins. The refrigeration loop (25) of the system (100) comprises a variable displacement compressor (30), a condenser (20), an expansion unit (40) and a heat exchanger (50), each of which is fluidly connected to one another to form a loop which performs refrigeration cycle. The refrigeration cycle is performed by continuous absorption and rejection of heat by a medium called refrigerant which is circulated in the refrigeration loop (25). During the flow, the refrigerant undergoes changes with respect to its fluidic and thermodynamic characteristics, as well as with respect to its physical and chemical properties.

The refrigeration loop (25) and the constituting units are identical to conventional vapour compression refrigeration system, except for the presence of heat exchanger instead of evaporator. The refrigeration loop (25), as clearly explained in previous paragraphs of detailed description, operates in the manner as following: the refrigerant, typically in liquid phase, absorbs heat from the space to be conditioned (or refrigerated) by the mode of convective heat transfer. According to an embodiment of the present disclosure, the refrigerant absorbs heat from a cooling solution circulating in a primary cooling loop (35), so that the temperature of cooling solution is reduced. The transfer of heat from cooling solution in primary cooling loop (35) to the refrigerant takes place in the heat exchanger (50). In an embodiment of the present disclosure, the heat exchanger (50) is a counter-flow (or counter current) type heat exchanger where cooling solution and refrigerant flow in opposite directions. The refrigerant vaporizes upon absorbing heat and moves into the variable displacement compressor (30) from the heat exchanger (50). The variable displacement compressor (30) compresses the vapour refrigerant to higher temperature and pressure. The compressed refrigerant is then passed into condenser (20) exposed to atmospheric air. The compressed vapour refrigerant passing through the condenser (20) rejects heat to surroundings and cools down to form liquid refrigerant (condensation). The condensed refrigerant is then expanded in the expansion unit (40) to form low temperature and pressure liquid refrigerant. This is again passed into heat exchanger (50) to absorb heat from the cooling solution to repeat the cycle. In an embodiment of the present disclosure, the refrigerant circulated in the refrigeration loop (25) includes but not limiting to Chloro-Fluro-Carbon (CFC) refrigerants, class of Freons, Ammonia or any other cryogenic liquid and gaseous refrigerating media which serve the purpose.

Further, as shown in FIG. 1, the multi-point cooling system (100) comprises a primary cooling loop (35) which is disposed in thermal communication with the refrigeration loop (25) through the heat exchanger (35). The primary cooling loop (35) is arranged such that heat is continuously transferred from the cooling solution to the refrigerant through heat exchanging process during the cycle. The working principle of a heat exchanger (50) is known in the art and is not explained in the detailed description part of the present disclosure. The primary loop (35) further comprises at least one reservoir (80) fluidly connected to the heat exchanger (50). The reservoir (80) stores the cooling solution and supplies it in required quantities for circulation in the primary cooling loop (35). In an embodiment of the present disclosure, the cooling solution in the reservoir (80) is water with anti-freeze substances such as glycols, including but not limited to ethylene glycol, propyl glycol and other glycol derivatives. In an embodiment, the glycol concentration in the glycol based solution is as minimum as 20%, so that the thermal properties, such as but not limiting to thermal inertia and thermal conductivity of the cooling solution are improved. In still another embodiment, the cooling solution is added with additives including but not limited to nano-particles to enhance thermal properties of the cooling solution. The nano-particles include but not limited to metallic ions, elements or compounds such as dispersed copper oxide, alumina and the like. The addition of nano-particles increases thermal conductivity and thermal diffusivity of the cooling solution without significantly affecting the thermal inertia values. The improvement in thermal properties of the cooling solution reduces time taken for initial cooling of the cooling solution during the cycle. The reservoir (80) containing the cooling solution is also thermally insulated to prevent heating of cooling solution during hot soak conditions. The insulation also helps in maintaining cooling temperatures of the cooling solution inside the reservoir (80), so that stable thermal equilibrium exists between incoming and outgoing cooling solution.

The cooling solution supplied by the reservoir (80) is circulated in the primary cooling loop (35) at desired delivery pressure by at least one first pump (60). The at least one first pump (60) is fluidly connected to the reservoir (80) through at least one first blower (70). When the first pump (60) is switched ON, suction is created in the fluid line in between the inlet of first pump (70) and outlet of the reservoir (80). This suction pressure draws the cooling solution from the reservoir (80) into the first blower (70). The first blower (70) discharges air over the cooling solution, so that heat transfer takes place from the air to the cooling solution. The air loses heat to the cooling solution and gets conditioned, which is then delivered into a first portion of the vehicle cabin (not shown). The conditioned air so delivered provides required cooling effect to the first portion and maintains temperature of the first portion at comfort levels. In an embodiment of the present disclosure, the first portion of vehicle cabin includes but not limiting to front portion of the passenger compartment comprising front row passenger space and dashboard. On the other hand, the cooling solution which absorbs heat from air to be conditioned is circulated into the heat exchanger (50) by the first pump (60). The heat of cooling solution is transferred to the refrigerant flowing through the refrigeration loop (25), as described in trailing paragraphs of detailed description. In an alternate embodiment of the present disclosure, at least one first fan is used in the place of at least one first blower (70) to deliver conditioned air to first portion of the vehicle cabin. One should not construe that blowers and fans are the only possible fluid delivering devices that can be used to deliver conditioned air. Any other fluid delivering devices which serve the purpose can be incorporated in the present system (100).

Referring again to FIG. 1, the reservoir (80) of the primary cooling loop (35) is in fluid communication with at least one secondary cooling loop (45). The secondary cooling loop (45) is identical to the primary cooling loop (35) except for the communication with the heat exchanger (50). The secondary loop (45) communicates with the reservoir (80). The reservoir (80) is fluidly connected to at least one second pump (45A). The second pump (45A) circulates cooling solution through the secondary cooling loop (45) at desired delivery pressure, in a manner identical to the first pump (60). A second blower (45B) fluidly disposed in between the second pump (45A) and the reservoir (80) delivers conditioned air to a second portion of the vehicle cabin, which includes but not limited to rear seat row, rear utility space, bottle holder and cup holder inside the passenger compartment. FIG. 1 which is an exemplary embodiment of the present disclosure illustrates single secondary cooling loop (45), and is not in any way limiting the scope of present disclosure. Any number of secondary loops can be incorporated depending on the number of cooling points required in the vehicle cabin. The multipoint cooling system (100) also includes at least one control valve (85) provisioned at outlet of the reservoir (80). The at least one control valve (85) is connected to the primary cooling loop (35) and the at least one secondary cooling loop (45). The at least one control valve (85) is configured to control the flow of cooling solution from the reservoir (80) to the primary cooling loop (35) and the at least one secondary cooling loop (45). The at least one control valve (85) is interfaced with a control unit (90). The control unit (90) provide signal to the control valve (90) to regulate the flow of cooling solution from the reservoir (80) to the primary cooling loop (35) and the at least one secondary cooling loop (45) for a predetermined period based on temperature of the vehicle cabin.

In an embodiment of the disclosure, the control unit (90) is also interfaced with the variable displacement compressor (30) and the control valve (85), and is configured to regulate output of the variable displacement compressor (30) based on temperature of cooling solution at exit of the heat exchanger (50).

FIG. 2 is an exemplary embodiment of the present disclosure which illustrates a flowchart depicting control logic used to operate control valve depending on vehicle cabin temperature. The multi-point cooling system (100) of the present disclosure comprises a control unit (90) interfaced with the variable displacement compressor (30) of the refrigeration loop (25) and at least one control valve (85) provisioned at exit of the reservoir (80). The control unit (90) is configured to regulate output of the variable displacement compressor (30) to modify temperature of air inside the vehicle cabin. In addition, the control unit (90) controls opening and closing of the control valve (85) to regulate flow of cooling solution from the reservoir (80) to the primary cooling loop (35) and the secondary cooling loop (45) for a predetermined period. The at least one control valve (85) includes flow control and directional control valve which determines flow rate and direction of flow of cooling solution from the reservoir (80). The control valve (85) is also configured to selectively introduce cooling solution into the primary and secondary cooling loops (35, 45).

Referring to FIG. 2, the control logic used to operate control valve (85) can be explained as following. When conditioning of air inside the vehicle cabin is not required, the multi-point cooling system (100) is switched off and the control valve (85) remains closed. During this condition, the reservoir (80) stores the cooling solution and the cooling solution is not circulated through the primary and secondary loops (35, 45). The first and second pumps (60, 45B) remain inoperative. On the other hand, if vehicle cabin is to be cooled, the system (100) is switched ON so that the primary cooling loop (35) and secondary cooling loop (45) can be selectively switched ON. If cooling of only the first portion of vehicle cabin is required, only the primary cooling loop (35) becomes operative and the control valve (85) opens to a first position (interchangeably referred to as position - 1). The opening of control valve (85) to first position is accomplished by the control unit (90). The opening of valve (85) to first position allows cooling solution to flow into the primary cooling loop (35), and the first pump (60) is operated to circulate the cooling solution through the loop (35). The flow rate of cooling solution through a primary cooling circuit is controlled by a control unit (90) by regulating a flow rate through the at least one first pump (60). In the situation such as hot soak conditions, the control unit (90) receives temperature value in the vehicle cabin through a temperature sensor [not shown], and accordingly controls the flow rate of cooling solution. If the temperature in the vehicle cabin is high, for example more than a predefined value, then the cooling solution is introduced only into the primary loop (35). Since coolant solution flows only in the primary loop (35) the coolant volume used is less, thus lesser time will be required to cool the cooling solution by the refrigerant in refrigeration loop (25). The cooling solution is then used to condition air by the first blower (70) provided in the primary loop (35), and the conditioned air is delivered to first portion of vehicle cabin.

When cooling is to be extended to second portion of the vehicle cabin, the control unit (90) actuates the control valve (85) to a second position (interchangeably referred to as position – 2) so that cooling solution flows both into the primary loop (35) and the secondary loop (45). Both first and second pumps (60, 45A) become operative and conditioned air is delivered to both first and second portions of vehicle cabin by first and second blowers (70, 45B) respectively. In an embodiment of the disclosure the second portion of the vehicle cabin includes rear passenger compartment, middle passenger compartment, bottle holder, cup holders, and refrigerators in vehicle. The reservoir (80) contains cooling solution of enough quantity to circulate in the primary loop (35) and the secondary loop (45) when both the operational at the same time.

FIG. 3 is an exemplary embodiment of the present disclosure which illustrates a flowchart to depict control logic of the control unit (90) to operate variable displacement compressor (30). The control unit (90) interfaced with the variable displacement compressor (30) regulates output (or displacement) of the compressor (30) to maintain the vehicle cabin temperature depending on fluctuations in atmospheric temperature conditions. The variable output of the variable displacement compressor (30) depends on modification in signals input to the compressor (30) by the control unit (90). The extent of compression of vapour refrigerant can in turn be varied by varying the compressor (30) displacement during refrigeration cycle. The control unit (90) in turn takes inputs of cooling solution temperature at exit of heat exchanger (50) and accelerator pedal position in the vehicle. The temperature of cooling solution at the exit of heat exchanger (50) is proportional to temperature of conditioned air inside the vehicle cabin. More particularly, the temperature of vehicle cabin can be varied by varying the cooling solution temperature appropriately. Hence, in one embodiment, the temperature of cooling solution at heat exchanger (50) exit is consider as indicative of temperature inside the vehicle cabin. The control unit (90) takes inputs from one or more temperature sensors provided at exit of heat exchanger (50). If the temperature of cooling solution is approaching the freezing point of cooling solution (equal to or slightly close to freezing temperature), the compressor (30) is cut-off so that further cooling of the cooling solution is stopped. In this way, the control unit (90) also prevents freezing of cooling solution inside the flow lines during operation, in addition to controlling the output of variable displacement compressor (30).

The control unit (90) also takes inputs from accelerator pedal position inside the vehicle, in addition to cooling solution temperature. If temperature of cooling solution is sufficiently higher than its freezing point and within the range of comfort level temperature, then the control unit (90) checks whether the vehicle is accelerating above a predetermined speed. If acceleration is higher, the compressor (30) is again cut-off so that cooling solution will not be cooled further by the refrigerant. If acceleration is within prescribed limits, the compressor (30) displacement is kept minimum. In this way, the control unit (90) prevents freezing of cooling solution during operation and reduces parasitic compressor (30) load on the engine. In alternate terms, the compressor (30) is made inoperative or less operative when temperature of cooling solution remains within the range of comfort level temperature during vehicle acceleration. The reduction of compressor (30) load on engine saves engine power considerably and improves engine output. Further, if the temperature of cooling solution at exit of heat exchanger (50) rises above comfort levels, the cooling solution has to be cooled down below comfort levels to provide optimum cooling. The rise in temperature of cooling solution is inevitable and is inherent with the introduction of more and more cooling solution. To bring down the cooling solution temperature to comfort levels, compressor (30) displacement is increased by the control unit (90) depending on vehicle acceleration pedal position. This is particularly useful during vehicle hot-soak conditions where cabin temperature can go upto 550 C, and cooling solution is to be cooled to a range of 15-200 C (comfort levels). The term “hot soak” refers to a condition inside the vehicle cabin where temperature increases significantly due to prolonged exposure to sun. Alternatively, hot soak refers to a condition in which the engine is shut-off and cylinder body transfers heat to the surrounding air by convection for cooling down the engine, as well as to the coolant passing through the engine block. The increase in temperature of coolant and air which surrounds the engine increases the temperature inside the vehicle cabin, resulting in passenger discomforts. The cooling solution circulated through the primary and secondary loops (35 and 45) bring down the hot-soak temperature of vehicle cabin to comfort levels.

In an embodiment of the present disclosure, the control valve (85) is configured to control the flow of cooling solution from the reservoir (80) to the primary cooling loop (35) and the at least one secondary cooling loop (45). The control valve (85) is interfaced with a control unit (90). The control unit (90) provides signal to the control valve (90) to regulate the direction and flow characteristics of cooling solution from the reservoir (80) to the primary cooling loop (35) and selectively to secondary cooling loop (45) for a predetermined period based on temperature of the vehicle cabin. If the temperature in the vehicle cabin is more than the predetermined limit, the control unit (90) actuates the control valve (85) to the first position (Position-1) so that flow of cooling solution into the secondary loop is cut-off. The control unit (90) also controls the flow through the first pump (60), such that a small amount of cooling solution is circulated through the primary loop (35) for a predetermined time. In an embodiment of the disclosure, the predetermined time limit is determined based on the temperature in the vehicle cabin. After the predetermined time, the control unit (90) actuates the control valve (85) to the second position, and allows the flow of cooling solution through the secondary loop (45). In an embodiment of the present disclosure, the control valve (85) is at least one of flow control valve including but not limited to pressure compensated and non-pressure compensated valves, and directional control valves including but not limited to 2-way, 3-way and 4-way directional control valves.

It is to be understood that a person of ordinary skill in the art would design and develop a multi-point cooling system of any configuration without deviating from the scope of the present disclosure. Further, various modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations, provided they come within the ambit of the appended claims and their equivalents.

Advantages:
The present disclosure provides a multi-point cooling system for a vehicle in which cooling can be extended to multiple locations within the vehicle cabin. The multi-point cooling system prevents the need of additional evaporators to extend cooling effect at different locations, making the system simple, compact and cost effective. This also increases maintainability of the system.

The present disclosure provides a multi-point cooling system for a vehicle which uses a variable displacement compressor. The output of variable displacement compressor can be varied to suit different temperature conditions inside the vehicle cabin, as well as to regulate cabin temperature within comfort levels when atmospheric temperature is fluctuating. Thus, compressor is flexible to meet varying temperature conditions inside the vehicle. The compressor output can also be regulated depending on accelerator pedal position by the control unit. This helps in reducing parasitic compressor load on the engine, and thereby helps in increasing engine power and performance.

The present disclosure provides a multi-point cooling system for a vehicle which uses a control valve to control flow of cooling solution. The control valve can be closed when the cooling system is switched off (i.e. non-operating condition) and can selectively allow flow of cooling solution into the secondary loop. This allows secondary loop to be selectively operated depending on cooling requirements in the second portion of vehicle cabin.

The present disclosure provides a multi-point cooling system for a vehicle in which the cooling solution circulated at low flow rates in the primary loop during hot soak condition of the vehicle. The low flow rate of cooling solution during hot soak condition helps in achieving faster cooling since low coolant volume requires lesser time to cool down inside the primary loop. This helps in achieving faster cooling of vehicle cabin during vehicle hot soak conditions.

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.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

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, with the true scope and spirit being indicated by the following claims.

TABLE OF REFERRAL NUMERALS

Referral Numerals Description
100 Multi-point cooling system
20 Condenser
25 Refrigeration loop
30 Variable displacement compressor
35 Primary cooling loop
40 Expansion unit
45 Secondary cooling loop
45A Second Pump
45B Second blower
50 Heat exchanger
60 First pump
70 First blower
80 Reservoir
85 Control valve
90 Control unit
,CLAIMS:We claim:
1. A multi-point cooling system (100) for a vehicle, the system (100) comprising:
a refrigeration loop (25) configured to facilitate flow of refrigerant, the refrigeration loop (25) comprising:
a heat exchanger (50) for vapourising the refrigerant;
a variable displacement compressor (30) fluidly connected to the heat exchanger (50) for compressing vapours of the refrigerant;
a condenser (20) fluidly connected to the variable displacement compressor (30) for condensing vapours of the refrigerant into liquid refrigerant; and
an expansion unit (40) fluidly connected to the condenser (20) for expanding the liquid refrigerant;
a primary cooling loop (35) configured to facilitate flow of a cooling solution, the primary cooling loop (35) comprising:
at least one reservoir (80) to store the cooling solution;
at least one first pump (60) fluidly connected to the least one reservoir (80) for circulating the cooling solution in the primary cooling loop (35), wherein, the cooling solution exchanges heat with the refrigerant in the refrigeration loop (25) through the heat exchanger (50); and
at least one first blower (70) provisioned in the primary cooling loop (35), the at least one first blower (70) configured to deliver conditioned air to a first portion of the vehicle cabin;
at least one secondary cooling loop (45) in fluid communication with the at least one reservoir (80), the at least one secondary cooling loop (45) is configured to cool a second portion of the vehicle cabin;
at least one control valve (85) provisioned at outlet of the reservoir (80), the at least one control valve (85) is configured to control the flow of cooling solution from the reservoir (80) to the primary cooling loop (35) and the at least one secondary cooling loop (45); and
a control unit (90) interfaced with the variable displacement compressor (30) and the control valve (85), wherein the control unit (90) is configured to:
regulate output of the variable displacement compressor (30) based on temperature of cooling solution at exit of the heat exchanger (50); and
regulate the flow of cooling solution from the reservoir (80) to the primary cooling loop (35) and the at least one secondary cooling loop (45) for a predetermined period based on temperature of the vehicle cabin.

2. The system (100) as claimed in claim 1, wherein the heat exchanger (50) is a counter-flow heat exchanger.

3. The system (100) as claimed in claim 1, wherein the control unit (90) regulates output of the variable displacement compressor (30) depending on accelerator pedal position.

4. The system (100) as claimed in claim 1, wherein the first portion of the vehicle cabin is front portion of the passenger compartment.

5. The system (100) as claimed in claim 1, wherein the second portion of the vehicle cabin is at least one of rear portion of the passenger compartment, refrigeration unit in passenger cabin, bottle holder and cup holder.

6. The system (100) as claimed in claim 1, wherein the at least one secondary loop (45) comprises at least one second pump (45A) for circulating the cooling solution.

7. The system (100) as claimed in claim 1, wherein the at least one secondary loop (45) comprises at least one second blower (45B) to deliver conditioned air to the second portion of the vehicle cabin.

8. The system as claimed in claim 1, wherein the cooling solution is a glycol solution comprising additives.

9. The system as claimed in claim 8, wherein the additives are nano-particles.

10. The system as claimed in claim 1, wherein the at least one first pump (60) is a variable displacement pump.

11. The system as claimed in claim 1, wherein the at least one first pump (60) is interfaced with the control unit (90).

12. The system as claimed in claim 11, wherein the control unit (90) is configured to regulate the flow of the cooling solution through at least one first pump (60) based on temperature in the vehicle cabin.

13. The system as claimed in claim 1, wherein the control unit (90) is configured to cut-off flow from the control valve (85) to the secondary loop (45) till the temperature of the vehicle cabin reaches below a predetermined value.