FORM-2
THE PATENTS ACT. 1970
(39 of 1970)
COMPLETE SPECIFICATION
(Section 10, rule 13)
Modified design & method of Desorber & Absorber with Solution flow control for vapour absorption air cooling system
By
Mr. Aganivesh Purushottam Ogale
S/O Mr. P. G. Ogale, Vidyabharati Colony, Near Bhilkheda Mandir, Karanja (lad) Tq.
Karanja (lad) dist. Washim, Maharashtra, India -444105
Email Id: - aganiveshogale@gmail.com
Mob. No.+91-7798653811
Dr. Ashok Kumar M. Vanageri
Principal, Shetty Institute of Technology, Rajapur- Shahabad Road ,
Kalaburagi, Karnataka, India-585105 Email Id: - vanageriashok@gmail.com Mob. No. +91-9480360560
Mr. Sagar Vishnurao Wankhede
S/O Mr. V. P. Wankhede, Opp. Railway Station, Adarsh College Road, Saraswati Nagar
Hingoli, Tq. Dist. Hingoli, Maharashtra, India-431512
Email Id: - svw8890@gmail.com
Mob. No.+91-9421387687
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED: -

FIELD OF THE INVENTION:
This invention relates to the field of Refrigeration and Air Conditioning.
More particularly, this invention relates to Vapour Absorption System.
More particularly, this invention relates to Generator and Absorber in Vapour Absorption System.
BACKGROUND OF THE INVENTION:
Researches from all over the world are trying to find alternative energy sources and efficient systems. Present invention aims to utilize exhaust waste heat from industries, automobile or solar energy to run vapour absorption air cooling system using lithium bromide & water (LiBr & H20). Fluctuating heat source make it difficult to use of vapour absorption cooling system which will run on waste heat or solar energy. At low temperature heat source, refrigerant is unable to separate from absorbent in generator which results in failure of the absorption system. At high temperature heat source, refrigerant gets over heated and will unable to condense in condenser which again results in failure of the absorption system. This difficulty is solved by the present invention by controlling the temperature of solution inside the generator with respect to variable heat source. Also, novel heat transfer mechanism is developed for generator and absorber for vapour absorption air cooling system which provides freedom for choosing various shapes and sizes of separator tank and absorption tank for specific application.

Problems in the existing vapour absorption air conditioning system runs on exhaust waste
* heat or solar energy:-
1. Small capacity (1 to 4 TR) vapour absorption air conditioning systems are not available.
2. Low coefficient of performance.
3. Crystallization of Lithium Bromide absorbent at high temperature.
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4. High size and weight for same capacity compared with vapour compression refrigeration system.
5. It is difficult to run the system on fluctuating heat source (Exhaust waste heat from Industries, Automobiles or Solar energy).
PRIOR ART:
Basic working principle of vapour absorption refrigeration cycle is based on liquid and vapour phase of refrigerant used. High pressure liquid refrigerant evaporates at low pressure and during evaporation it collects latent heat of vaporization which results in cooling effect. Strong solution (Absorbent & refrigerant) from absorber at low pressure is fed to generator at high pressure with the help of pump. Heat is added to this strong solution inside the generator from heat source. High pressure hot solution inside the generator rejects vapour refrigerant which then passes into condenser and weak solution containing less amount of refrigerant vapour passes into absorber through expansion valve. Expansion valve reduces the pressure of weak solution equal to the pressure of absorber. High pressure, high temperature vapour refrigerant changes its phase from vapour to liquid inside the condenser by rejecting heat to atmosphere. Liquid refrigerant

at high pressure then passes through expansion valve where pressure of refrigerant reduces. Low pressure liquid refrigerant evaporates inside the evaporator by collecting its latent heat of vaporization. Cooling effect of the system is achieved at evaporator. Vapour refrigerant at low temperature and low pressure from evaporator then passes into absorber where it gets absorbed by low temperature weak solution results in strong solution. Heat addition takes place in generator & evaporator and heat rejection takes place in condenser & absorber. COP (coefficient of performance) of the system is totally depends on these heat addition and rejection processes. For greater COP heat addition to generator should be minimum and to evaporator should be maximum.
When heat source for generator is fluctuating then system shows unfavorable performance. For example, suppose the heat source for generator is exhaust waste heat from automobile engine. Depending upon the engine running conditions, exhaust gas temperature varies. At lower speed or idling condition, temperature of exhaust gas is low which is not capable to heat the generator solution up to required temperature to separate the vapour refrigerant from absorbent. Also, at higher speed, temperature of exhaust gas is so high that will superheat the vapour refrigerant. Superheated refrigerants will fail to condense inside the condenser. Same is valid for solar energy, as solar energy received from the Sun is variable throughout the day depending upon the position of the Sun.
This problem can be eliminated by the present invention. Present invention aims to maintain constant generator, absorber and condenser temperature at variable heat source temperature.

OBJECT OF THE INVENTION:
An object of the invention is to provide solution to run vapour absorption system on
variable heat source (Waste heat from Industries, Automobile or Solar energy).
Another object of the invention is to avoid overheating of the generator solution.
Another object of the invention is to maintain constant generator, condenser and absorber
temperature for variable heat source.
Another object of the invention is to provide efficient heat transfer mechanism for heat
addition to generator and heat rejection from absorber.
Yet another object of the invention is to improve the coefficient of performance of system
by optimizing the generator temperature.
Yet another object of invention is to reduce size and weight of the system.
Yet another object of invention is to provide control system for flow control valve.
STATEMENT OF INVENTION:
Temperature of solution inside the generator is controlled by changing the mass flow rate of solution through heat adding heat exchanger. Specific required temperature of solution can be maintained for maximum refrigerant separation, optimized COP, low condenser and absorber load. Heat transfer process is directly proportional to the time of contact between two heat exchanging fluids. If time of contact between the fluids is longer, more heat is transferred and temperature difference between the fluids reduces and vice versa. This phenomenon is used in present invention for controlling the mass flow rate of solution with respect to temperature. As temperature changes, mass flow rate of solution also changes in order to keep constant solution temperature. At higher temperature, mass

flow rate will be high which results in less time of contact between the heat exchanging fluids. At lower temperature, mass flow rate will be low, so as to provide more time for contact between the heat exchanging fluids which results in more heat transfer.
SUMMARY OF INVENTION:
According to this invention, provision is made for controlling mass flow rate of solution through generator with respect to temperature and novel heat addition to generator and heat rejection from absorber. Lithium bromide as an absorbent and water as a refrigerant is used in the system. Said system comprises:
- Flow control valve is fitted in bypass line between pump and fin tube heat exchanger.
- Flow control valve operated manually or electrically based on temperature reading or signal.
- Output of flow control valve is connected to discharge line from separator tank through expansion valve.
- . Fin tube heat exchanger is fitted between discharge line from separator tank
through expansion valve and absorption tank.
Fin tube heat exchanger connected on absorption tank is cooled by fan, connected centrally to the exchanger, on generator side.
- Another Fin tube heat exchanger is fitted in passage line between pump and separator tank.
- Electrical heater is used for supply of hot air over fin tube heat exchanger between pump and separator tank. *

- Fan fitted, for cooling fin tube heat exchanger on absorption tank line, supplies hot air as an input for electrical heater.
Typically, said flow control valve on new bypass line added to pump discharge.
Typically, said flow control valve operation is manual or automated.
Typically, said new output line added.
Typically, said new heat transfer mechanism is added for absorber.
Typically, said heat transfer mechanism of absorber is air cooled by fan.
Typically, said new heat transfer mechanism is added for generator.
Typically, said heat source for system is electric heater.
Typically, said heat out from absorber heat exchanger is added to source heat.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING:
The invention will now be described in relation to the accompanying drawing, in which: Figure 1 illustrates schematic diagram of various part involved in our invention.
Reference numeral 1 relates to pump.
Reference numeral 2 relates to fin tube heat exchanger for generator
Reference numeral 3 relates to separator tank
Reference numeral 4 relates to air cooled condenser
Reference numeral 5 relates to expansion valve
Reference numeral 6 relates to evaporator
Reference numeral 7 relates to absorption tank

Reference numeral 8 relates to fin tube heat exchanger for absorber
Reference numeral 9 relates to electric heating coil
Reference numeral 10 relates to pressure reducing valve
Reference numeral 11 relates to flow control valve
Reference numeral 12 relates to heat exchanger fan
Reference numeral 13 relates to thermocouple
Reference numeral 14 relates to evaporator fan
Reference numeral 15 relates to tube in tube heat exchanger
Reference numeral 16 relates to pressure relief valve
Reference numeral 17 relates to condenser fan
Reference numeral 18 relates to rotameter
Reference numeral 19 relates to pressure gauge
Reference numeral 20 relates to vacuum gauge
In the present drawing of invention, pump (1) is connected to absorption tank (7) downstream and to generator heat exchanger (2) upstream. Vacuum gauge (20) downstream to pump (1) is used to measure suction pressure. Rotameter (18) and flow control valve (11) is on bypass line upstream to pump (1). Thermocouple (13) and pressure gauge (19) is used to measure pressure and temperature on upstream to pump (1). Electric heater (9) as a heat source for fin tube heat exchanger (2) with two thermocouples (13) at inlet and outlet of exchanger (2) is followed by fan (12) and fin tube heat exchanger (8). Separator tank (3) is upstream to fin tube heat exchanger (2) and condenser (4). Pressure gauge (19) and thermocouple (13) upstream to separator tank (3) is used to measure pressure and temperature of vapour refrigerant. Pressure gauge (19),

thermocouple (13), rotameter (18) and pressure reducing valve (10) is on solution outlet line to separator tank (3). Pressure relief valve (16) is attached, on bypass line from outlet line to separator tank (3) and on downstream line of condenser (4). Condenser is air cooled by fan (17). Thermocouple (13), rotameter (18), expansion valve (5), vacuum gauge (20) and tube in tube heat exchanger (15) are on downstream to condenser (4). Refrigerant evaporates in evaporator (6) and passes through tube in tube heat exchanger (15) into absorption tank (7). Fan (14) is used to take out cooling effect from evaporator (6).
DETAILED DESCRIPTION OF THE INVENTION:
According to this invention, there is provision of solution mass flow rate control (11) through generator with respect to change in temperature. Initially, strong solution fed by pump (1) is passed through main line (fin tube heat exchanger line (2)) as well as bypass line (flow control valve line (11)) in some specific proportion as shown in figure 1. It means flow control valve is partially open initially. Heat added into fin tube heat exchanger solution with the help of heat source. Heat source may be waste heat from industry, automobile or solar energy. In present invention, heat source is considered as an electric heater (9) for experimentations. Strong solution inside the fin tube heat exchanger (2) gets heated and then passed into separator tank (3). In separator tank (3), vapour refrigerant gets separated due to the property of absorbent. Property of absorbent is to rejects vapour refrigerant at high temperature and absorbs vapour refrigerant at low temperature. Vapour refrigerant separated inside the separator tank (3) then passed into condenser (4). Weak solution from separator tank then passed into outlet line connected to fin tube heat exchanger (8) of absorber. On this line, temperature sensor (13) is

installed which measures the temperature of weak solution coming out of separator tank (3). This temperature is the input for flow control valve (11) to control strong solution flow through bypass line. As flow through bypass line increases or decreases by opening or closing of flow control valve (11), strong solution flow rate decreases or increases accordingly. Gradual opening or closing of flow control valve (11) can be monitored manually or some electronic control unit. Flow control valve (11) will gradually open or close so as to maintain constant set temperature of solution inside separator tank (3).
For example, if required temperature of solution inside separator tank (3) is 80°C. As heat source is fluctuating, suppose temperature of heat source is suddenly increased which results in solution temperature rise to 100°C for specific flow rate through heat exchanger (2). For this situation, flow control valve (11) will start closing gradually in order to decrease flow rate through bypass line and increase solution flow rate through heat exchanger (2). Solution flow rate from pump (1) is kept constant for all operations. As flow rate of solution through heat exchanger increases (2), time available for heat exchange process between the fluids reduces, which results drop in temperature of solution. Flow control valve (11) will stop at that point where temperature of solution reaches to 80°C. Same operation is performed by flow control valve (11) when there is drop in temperature of solution. When temperature of solution needs to be increased, in such cases flow control valve (11) will start opening up to that point at which temperature of solution reaches to desired value.
Also, in present invention, heat addition to generator and heat rejection from
absorber processes is made separated with the help of fin tube heat exchangers.

Generally, in existing systems heat addition to generator and heat rejection from absorber

is made possible by adding heating and cooling coils internally. This will result in constraints on generator and absorber shapes and designs. In present invention, as heat addition and heat rejection processes made outside, there is a scope of various shapes and designs of separator tank (3) and absorption tank (7) depending upon type of application. Also, efficient heat transfer mechanism is provided for theses heat exchange processes in present invention. The novel features include in present invention:
System which provides solution to use fluctuating heat source for refrigeration &
air conditioning application.
System provides required constant generator, condenser and absorber
temperature.
System which control flow rate with change in solution temperature.
System provides efficient heat exchange processes for generator and absorber.
System provides freedom for choosing desired shape and design of separator tank
and absorption tank.
System can cause revolution in refrigeration & air conditioning systems.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. Solution flow rate control through generator with respect to change in temperature of solution inside the generator.
2. System can maintain required constant temperature of generator at fluctuating heat source.
3. System can maintain constant temperature of condenser at fluctuating heat source.
4. System can maintain constant temperature of absorber at fluctuating heat source.
5. Efficient heat addition process for generator.
6. Efficient heat rejection process for absorber.
7. Elimination of Lithium Bromide crystallization problem.
8. System provides independency for shapes and designs of separator tank.
9. System provides independency for shapes and designs of absorption tank.