Title of Invention

SENSIBLE REFRIGERATOR AND AIR CONDITIONER WHICH CHANGES DIRECTION ACCORDING TO MICRO CLIMATIC CONDITIONS IN ITS VICINITY

Technical Field of Invention

The invention is related to the field of refrigeration and air conditioning. Particularly it is related to the heat exchanger of the heat rejecting unit.

Background Art or Prior Art

In the prior art many useful studies and inventions have been made to improve the heat exchanging rate of the heat exchanger used in condensing unit of the refrigerators and air conditioners. Direction adjustment of the following components of any refrigeration or air conditioning system has been done. a. Complete heat rejecting unit or condensing unit.

b. The heat exchanger coils.

c. Draught fan.

d. Fins of the heat exchanger.

e. Combination of any of the above written.

In order to optimize or maximize the mass flow rate of the air entering into the heat exchanger coils. So that maximum heat exchanging rate can be obtained under given set of operating conditions under which the system is working. Patent application number IN201811000258 describes an air-conditioning system in which the fins of the heat exchanger of heat rejecting unit changes its direction to facilitate entry of more air into the heat exchanger. WO 2015180142 A1 (TRANE AIR CONDITIONING SYTEMS (CHINA) CO LTD et al.) 03 December 2015 discloses a method to sensibly change the direction and orientation of an outdoor heat exchanger according to wind direction. Also CN 201672222 U (YUNSHENG, Xiao) 15 December 2010 discloses a condenser ( heat exchanger ) which can be rotated so

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SUBSTITUTE SHEETS (RULE 26) that the air inlet always faces the direction from where wind is flowing in order to increase the mass flow rate of the air entering into the condenser. All the prior art provide a method and apparatus to increase the mass flow rate of the air entering into the heat exchanger or condenser. The present invention is characterized by the heat rejecting unit comprising of direction and orientation adjusting mechanism in which complete heat rejecting unit and / or any of its parts such as heat exchanger coils, heat exchanger fins, the heat exchanger draught fan, heat exchanger fins. Changes its/ their direction in that particular orientation where not only maximum mass flow of air entering into the heat exchanger is maximum but also the ambient temperature in its vicinity at that particular orientation is minimum. The direction adjusting unit and/or its parts changes their direction on the basis of a ratio i.e the ratio of mass flow rate of air entering into system to the ambient temperature in the vicinity of heat exchanger at a particular orientation.

Many scientific studies published by reputed publishers have shown the phenomenon of occurrence of temperature and relative humidity variations of air in the proximity or vicinity of the heat rejecting unit’s heat exchanger. Existence of different microclimate zones on different sides or directions with respect to the condenser of the air conditioning or refrigeration system is a common phenomenon. These microclimatic zones show different levels of physical properties of air enclosed within them. Variations in Temperature, relative humidity of air and wind velocity in the different zones occur most commonly. These variations occur due to following reasons a. Due to the presence of obstacles in flow of wind like building walls or vents provided in the buildings.

b. Due to the cascading effect of other air conditioning units working in close proximity of the system. The heat rejected by them to the atmospheric air. The same air or part of it gets sucked into the heat rejecting unit of the system.

c. Direct sunlight or heat radiations exposure of any one side of the heat rejecting unit or heat exchanger.

d. Heat radiations reflected by the reflective wall surfaces or building components to the any one side of the heat exchanger or heat rejecting unit.

e. Temperature variations existing on different sides due to hot air recirculation. If the wind is blowing in one particular direction in some cases a condition may exist when the hot air coming out of the cooling space again sucked into the heat exchanger of the heat rejecting unit. Occurrence of this phenomenon increases the effective ambient

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SUBSTITUTE SHEETS (RULE 26) temperature and relative humidity for the system. Resulting in decreased values of COP and EER for the system.

f. Effect of shading on one side of the heat exchange. The shading may from the shade caused by natural (like trees) or artificial objects ( like manmade shades or shadows cast by buildings or walls) also result in occurrence of very small temperature variations. g. Presence of dampness or moist walls and other surfaces on any side of the heat rejecting units.

The effect on temperature of causes written above in points‘b’ to‘e’ can be considerable. So if an air heat exchanger of the heat rejecting unit is designed for any refrigeration and air conditioning system in such a way that it takes-in the maximum amount of air as coolant at minimum possible ambient temperature for the given set of operating conditions. The Coefficient of performance (COP) and Energy efficiency ratio (EER) of the system will improve considerably.

The following complete specification fully and particularly describe the invention and its operation or use and the method by which it is performed.

Technical Problem

As the cooling requirement for the comfort and industrial purposes increases. The pressure to improve the Coefficient of performance (COP) and Energy efficiency ratio (EER) of the air conditioning and refrigeration system is also increasing. The values of COP and EER of the system increases with the increase in the heat rejection rate (HRR) of the heat rejecting unit of the systems. The objective of this invention is to increase the value HRR.

Solution to Problem

Direction adjustment of different components of heat rejecting unit is done in many prior art with the sole objective to maximize or optimize the mass flow rate of the air entering into the heat exchanger of the unit. So that the heat rejection rate (HRR) can be maximized. No consideration is given to optimize the heat rejection rate of the heat exchanger by sensibly adjusting the direction of the heat exchanger or heat rejecting unit according to the different

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SUBSTITUTE SHEETS (RULE 26) ambient temperature occurring on different sides of the heat exchanger or heat rejecting. So that the heat exchanger takes-in the maximum amount of air as coolant at minimum possible ambient temperature for the given set of design and operating conditions. This will increase the HRR and thus the COP and EER values of the system.

Summary of Invention

The invention is related to the field of refrigeration and air conditioning system. More particularly to the heat exchanger of the heat rejecting unit of the system. The invention provides a novel method and design of the apparatus to adjust the direction of the heat exchanger or the heat rejecting unit of the system according to presence of different microclimatic conditions present on different sides or directions of the heat exchanger or the heat rejecting unit of the system. Variations in Temperature, relative humidity of air and wind velocity in the different micro climatic zones occur most commonly. In order to achieve the maximum possible value of the COP and Energy Efficiency Ratio for the system by sensibly and logically changing the direction of the heat rejecting unit of the system and then keeping itself in that particular direction . So that the heat exchanger takes-in the maximum amount of air as coolant at minimum possible ambient temperature for the given set of design and operating conditions. In order to get maximum value of COP and EER for the system working to obtain a given value of evaporating temperature ‘T ₂ ’ , under given set of design and working conditions. The system has to work where the maximum value of the fraction of m / Ti is obtained. The heat exchanger or the heat rejecting unit has to adjust itself in such a direction where this value is maximum for the given design and working conditions. That is for the given working conditions the value of mass flow rate of air entering into the heat exchanger‘m’ is maximum and simultaneously the value of ambient temperature of the air ‘TT in that particular direction is minimum.

In an another embodiment of the invention the heat exchanger of the heat rejecting unit or the complete heat rejecting unit or a component of it adjust its direction in such manner that for the given design and working conditions the value of the fraction m / T _w remains maximum for the system. That is the value of fraction obtained by dividing the value of mass flow rate of air entering into the heat exchanger‘m’ by the value of wet bulb temperature T _w of the air entering into the heat remains maximum during the working cycle of the system.

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SUBSTITUTE SHEETS (RULE 26) In one more embodiment of the invention Air Guides or Vanes are provided in front of the atmospheric air inlet side of the heat exchanger in addition to all the components or options described in the invention.

Theoretical Framework

In order to understand the invention completely first of all it is essential to understand the theoretical framework on which the invention is based upon. The following steps explain the theoretical facts which prove how the invention is beneficial and useful.

1. The Coefficient of performance (COP), Energy efficiency Ratio (EER) of any refrigeration and air conditioning system depends upon the heat rejection rate (HRR) of the heat exchanger used in heat rejecting unit or condensing unit or condenser of the system. The higher the heat rejection rate (HRR) higher will be the value of COP and EER for the system.

2. The heat rejection rate (HRR) value of the heat exchanger in which air is circulated as coolant around the coils of the refrigerants, depends on the mass flow rate of the air (m) entering into the heat exchanger. The higher the value of‘m’ higher will be the value of HER.

The amount of heat rejected by an air heat exchanger (QR) is given by

QR= m*c ( T _{out -} Ti) . equation 1.

Where

c is the specific heat value of the Air.

Tout is the absolute temperature of the air after passing through the air heat exchanger in degree Kelvin.

Ti is the temperature of the air entering into the heat exchanger. It is the considered as the ambient temperature in degree Kelvin.

3. Further ideal Coefficient of Performance COPcamot of a theoretical refrigeration cycle is given by

COPcamot = T2 / (Ti - T2) . equation 2.

Where

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SUBSTITUTE SHEETS (RULE 26) T2 is the evaporating temperature in degree Kelvin .

Ti is the ambient temperature or the temperature of the sink in degree Kelvin.

It is clear from the equation 2 that if the value T2 is kept constant. Then COPcamot of the system increases with decrease in ambient temperature or the temperature of the heat sink. In case air is circulated as coolant in the heat exchanger, the temperature of the air in the close vicinity of the heat exchanger is considered as sink temperature i.e. Ti.

Also from equation 1 it is easy to deduce that amount of heat rejected Q _R is directly proportional to the mass flow rate‘m’. Hence heat rejection rate‘HRR’ and further coefficient of performance of the system‘COP’ is directly proportional to‘m’.

Therefore we can deduce that

COP m / Ti expression 3.

That is COP of the system is directly proportional to‘m’ and inversely proportional to‘TT.

In order to get maximum value of COP for the system working to obtain a given value of evaporating temperature‘T2’ , under given set of design and working conditions. The system has to work where the maximum value of the fraction of m / Ti is obtained. Considering the presence of different microclimatic conditions in different directions of the heat exchanger or heat rejecting unit. The heat exchanger or the heat rejecting unit has to adjust itself in such a direction where this value is maximum for the system. That is for the given working conditions the value of mass flow rate of air (unit/ second) entering into the heat exchanger ‘m’ is maximum and simultaneously the value of ambient temperature of the air‘TT (in degree Kelvin) in that particular direction is minimum.

4. If the heat exchanger of the heat rejecting unit is partly water circulating or condensate water collected in the heat exchanger is circulated as coolant along with atmospheric air. Then the value of relative humidity of the air plays a key role in the heat rejection rate of the heat exchanger. The value of wet bulb temperature T _w (in degree Kelvin) acquires more relevance in these scenario. Then in this case the system can be designed where the heat exchanger or the heat rejecting unit or any of its component adjust their direction

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SUBSTITUTE SHEETS (RULE 26) where the value of the fraction of ml T _w is maximum for the working duartion of the system.

This invention provides a novel method and design of the apparatus to adjust the direction of the heat exchanger or the heat rejecting unit of the system according to presence of different microclimatic zones present on different sides or directions of the heat exchanger or the heat rejecting unit of the system. So that the maximum value of the fraction m/Ti is obtained during the working period of the system.

Description of Design

As shown in the Diagram 1 the enclosed space (11) depicts the space where evaporating temperature‘ T2’ is maintained by the system. (12) Shows the evaporating unit of the system along with the microcomputer (22) which is installed inside the cooling space.

The heat rejecting unit (20) of the system which is installed outside the cooling space is connected to the evaporating unit through the refrigerant pipes (15). The heat rejecting unit consists of a compressor (16) and a finned heat exchanger shown as meshed surface. On the appropriate points on the heat exchanger air mass flow meters (18) are installed to measure the mass flow rate of the air entering into the heat exchanger. Also on the heat exchanger at appropriate points, air temperature sensors (19) are installed to measure the temperature of the air entering into the heat exchanger Ti or in case of Embodiment 2 of the invention (19) shown in Diagram 1 are the wet bulb temperature sensors to measure the value of T _w . These air flow meters and temperature sensors are connected to the microcomputer of the system with the help of wires (21) in order to send data of the mass flow rate of the air entering into the heat exchanger‘m’ and temperature of air entering into the heat exchanger‘ TT in different direction of the heat exchanger. The sensitivity and fidelity of the both meters (18) and the sensors (19) are selected depending upon the required amount of accuracy required to measure the values and durability of the system. The response time of the meters and the sensors should be excellent so that they should be able to measure the values in any given direction of the heat exchanger or the heat rejecting unit in minimum possible time. The number these sensors and meters used depend upon the amount of accuracy, cost effectiveness desired and processing power of the microcomputer In case more than one meter or sensor is

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SUBSTITUTE SHEETS (RULE 26) used the value of‘m’ and Ti or T _w is taken as average value of respective readings given by the them.

In order to adjust the heat exchanger or the heat rejecting unit or the fins of the heat exchanger in any possible direction a stepper drive mechanism along with pivot (17) is provided in the heat rejecting unit. The stepper drive is coupled to a stepper motor which is controlled by the microcomputer of the system. In order to provide degree of freedom to the heat exchanger or the heat rejecting unit to adjust its direction, swivel joints are provided in the refrigerant pipes (13, 14).

The Best Method of Performing the Invention

Embodiment 1

The system when prompted by microcomputer starts measuring the values of ‘m’ and Ti in different directions. These direction adjustments are done by the system by adjusting the direction of any of the following written component or combination of components of the system.

Direction Adjusting Components of the System a. Complete heat rejecting unit or condensing unit.

b. The heat exchanger coils.

c. Draught fan.

d. Fins of the heat exchanger.

e. Combination of any of the above written.

The components or combination can be made to swivel or rotate in any relevant plane (horizontal and vertical planes as shown in Diagram 1) by providing a stepper drive mechanism along with pivot (17) at any point on the component, which is designed to adjust its direction. This design decision that which component or the combination is selected from the above written options is dependent upon many factors. The major factor on the basis of which the decision is taken is on the basis of the relative effectiveness achieved in terms of variations in the value of ‘m’ and ‘Tr through the direction adjustment of any of the component of the system with respect to the variations in the values achieved if another

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SUBSTITUTE SHEETS (RULE 26) component or the combination is selected to adjust its direction. The associated cost and type of installation of the heat rejecting unit or the outdoor unit also play the major role in taking the design. Thus the location of point (17) shown in the Diagram 1 can change based on the option selected in the design decision.

In case the Fins are allowed to adjust their direction. One end of each fin is connected to a common sliding gate which is further connected to a stepper drive.

The system with help of air mass flow meters (18) and the temperature sensors (19) send the data related to every incremental direction adjustment of the direction adjusting component of the system to the microcomputer (22). The direction increments (in terms of degrees of rotation in relevant plane/s) at which the direction adjusting component/s of the system should stop should be decided on the basis of level of climatic variations occurring in the vicinity of the heat rejecting unit. Normally after 15 to 30 degrees of rotation in relevant plane/ s a reading is taken. The time duration for which the direction adjustment system should stop during a reading is taken is dependent upon on the response time of the meters and sensors and processing capacity of the microcomputer. The microcomputer having sufficient data processing capacity compares the data related to all the incremental directions of the values of ‘m’ and Ti. The microcomputer calculates the value of the fraction‘m/TT for all the incremental directions. It takes a logical decision and sends commands to the stepper motor of the stepper drive mechanism to rotate the direction adjusting component/s in that particular direction where maximum value of the fraction‘m / TT is found. In this manner the system keeps on working in the direction where the maximum value of the fraction‘m / T is attained under the given set of working condition. The system keeps on working in the same manner unless or until again prompted by the microcomputer to seek data related to the value of the fraction‘m / TT-

Embodiment 2

If the heat exchanger of the heat rejecting unit is partly water circulating or condensate water collected in the heat exchanger is circulated as coolant along with atmospheric air. Also for the systems with dry heat exchangers which are working in hot and humid geographical regions. Then the value of relative humidity of the air plays a key role in the heat rejection rate of the heat exchanger. The value of wet bulb temperature T _w (in degree Kelvin) acquires more relevance in this scenario than the value of Ti. Then in this case the system is designed

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SUBSTITUTE SHEETS (RULE 26) where the heat exchanger or the heat rejecting unit or any of its component adjust their direction where the value of the fraction of m / T _w is maximum for the working duration of the system. The option described in this embodiment is important when the system is working tropical humid climate.

For the design description of Embodiment 2 also refer to Diagram 1. All parts explained in Embodiment 1 remain same for the Embodiment 2 except in case of Embodiment 2 of the invention (19) shown in Diagraml are the wet bulb temperature sensors to measure the value of Tw .

Embodiment 3

In this embodiment of the invention Air Guides or Vanes are provided in front of the atmospheric air inlet side of the heat exchanger in addition to all the components or options described in Embodiment 1 of the invention. These air guides or vanes are allowed to adjust their direction either independently or in combination of the direction adjusting components of the system mentioned in Embodiment 1. Please refer to the Diagram 2 for the purpose of Embodiment 3. The heat rejecting unit is shown as (20). The air guides or vanes (25) are attached in front of air inlet side of the heat exchanger of the heat rejecting unit. They cover the inlet side either partly or fully in order to guide the air from one particular direction into the heat exchanger. The air guides or vanes are installed taking the length of the guide plates either along the horizontal plane or vertical plane. In the Diagram 2 the guide plates are shown installed by taking their length along the vertical plane. They are installed in a manner that they form extended surface (Extended fins) for the heat transfer for the heat exchanger. Therefore they are made of any good heat conducting material and joined to the heat exchanger coils (the joint is shown as 26) or fins at multiple points with help of any good heat conducting material. Where (15) shows the heat exchanger coil circulating refrigerant through the heat exchanger. Preferably the guides or vanes are made from the same material as the heat exchanger coils or fins are made, in order to avoid the formation of heat barriers or at their joints. In this embodiment extra material and design dimensions is added to the system therefore it is described in separate embodiment of the invention.

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SUBSTITUTE SHEETS (RULE 26) With the addition of extra dimensions and creation of extended heat transfer surface for the system the Heat rejection rate increases. Heat rejection rate also improves due to selective air intake by the heat exchanger in that particular direction as guided by the air guides or vanes. The direction in which the value of the fraction obtained when the value mass flow rate of the air‘m’ entering into the heat exchanger of the heat rejecting unit is divided by the value of temperature of air‘Tr entering into the heat exchanger (that is mJ Ti ) is maximum. Thus improving the COP and EER values of the system. The value of ‘m’ is provided by strategically placing the air mass flow meter/s (18) and the value of Ti is obtained from strategically placed temperature sensor/s (19).

In this embodiment also if the heat exchanger of the heat rejecting unit is partly water circulating or condensate water collected in the heat exchanger is circulated as coolant along with atmospheric air. Then the value of relative humidity of the air plays a key role in the heat rejection rate of the heat exchanger. The value of wet bulb temperature T _w (in degree Kelvin) acquires more relevance in this scenario than the value of Ti. Then in this case the system is designed where the air guides or vanes alone or in combination with any of the direction adjusting components of the system described earlier adjust their direction where the value of the fraction of m / T _w is maximum for the working duration of the system. The option described in this embodiment is important when the system is working tropical humid climate.

The direction adjustment of the air guides or vanes is done by connecting the guides to common slider gate/s ( in Diagram 2 shown as 24). The slider gate/s is/are hinged to each guide plate (23). The slider gate/s usually placed normal to the length of the guide plates. The slider gate/s is/ are further connected to stepper drive mechanism (17) with the help of hinged joints. The hinged joint may contain a bush bearing or ball bearing in order to provide free rotation with lesser wear and tear to the joint.

For the design purpose the length, breadth and thickness of the guide plates and the sliding gate is selected in such a way that

The value of toughness and durability is high enough as the plates are directly exposed to the outer environment. Along with that the high value of thickness and breadth of the plates causes restriction in the air flow. Also the material consumption and cost of the system increases with increase in thickness and breadth of the plates. So a trade-off is reached which satisfy all the design requirements discussed above.

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SUBSTITUTE SHEETS (RULE 26) A clearance is provided between the plates and the heat exchanger coils or the fins of the heat exchanger so that the plates can change direction freely without any obstruction. More than required value of the clearance reduces the effect of direction guidance by the guide plates provided to the plates.

Advantageous Effects of the Invention

The COP and energy efficiency ratio of the system, which works on the direction adjustment mechanism in order to maximize the values of the ratios‘m/TT or m / T _w improves as compared to the system which work on the direction adjustment mechanism only to maximize or optimize the value of ‘m’ alone. The objective of the invention is to design a refrigeration and air conditioning system which adjusts the direction of its heat rejecting unit or its components so that maximum amount of air is pushed through the air heat exchanger along with the minimum possible temperature of the air for the given design and working conditions.

Operational Definitions a. System: Any refrigeration and/or air conditioning system which operates on any principle or cycle. This absorbs heat from any cooling space and rejects the heat to the atmosphere.

b. Heat Rejecting Unit: The unit of the system which rejects heat to the atmosphere. It uses heat exchanger/s which uses atmospheric air either fully or partially to act as a coolant. The coolant circulates in the heat exchanger coils and carry away heat from the refrigerant pipes or the fins of the heat exchanger.

c. Relevant Plane/s: The plane/s in which any heat rejecting unit or any component of the heat rejecting unit rotate or swivel. The horizontal plane is along the ground and the vertical plane is normal to the ground.

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SUBSTITUTE SHEETS (RULE 26) d. Degree of freedom: It is angular degree of freedom the heat rejecting unit or its component/s can rotate or swivel freely in any or both of the relevant planes. For wall mounted air conditioners the degree of freedom is restricted to 180 degrees and for roof top or ground mounted air conditioners the degree of freedom can be 360 degrees of angular rotation in the horizontal plane.

Industrial Applicability

The invention is applicable to any refrigeration and /or air conditioning system used for any industrial/ commercial or residential needs.

Abbreviations Used

COP: Coefficient of performance of the system. EER: Energy Efficiency Ratio HRR: Heat Rejection Rate

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SUBSTITUTE SHEETS (RULE 26)