FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2006
COMPLETE
Specification
(See Section 10 and Rule 13)
A HYBRID POWER GENERATION SYSTEM AND METHOD
THEREOF
THEHMAX LIMITED
an Indian Company of D-13, MIDC Industrial Area, R.D. Aga Road,
Chinchwad, Pune - 411 019, Maharashtra, India.
Inventors: 1. SONDE RAMKRISHNA 2. DESHPANDE GAJANAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

FIELD OF DISCLOSURE
The present disclosure relates to a power generation system and method thereof. Particularly, the present disclosure relates to a hybrid power generation system using renewable energy sources.
BACKGROUND
Traditionally, electricity is generated by burning fossil fuels such as coal, oil, lignite, natural gas, and the like, this heat energy is transferred to water for boiling to obtain superheated steam which is subsequently expanded in a steam turbine to produce mechanical energy/work. This work is later extracted by means of a generator to produce useful electrical energy. Although, fossil fuels are still most commonly used in power generation facilities, its use is coming under a scanner due to the heavy pollution concerns caused by the greenhouse gas emissions of carbon dioxide during the burning of the fossil fuels. Other options like nuclear power find very limited application due to the high costs, large foot-print and difficult-to-control operation.
Renewable energy sources like biomass, solar energy, geothermal energy, and wind energy have been explored, but one of the major drawbacks of these renewable sources is that the heat energy available is not sufficient to attain superheated temperatures, thereby requiring an additional heat source. Other drawbacks include: biomass has high water content and low energy, therefore transportation cost is high and the application is not feasible; solar energy is not available throughout the year, also sufficient energy storage to obtain 24/7 operation is difficult even with an increased solar field. Therefore, power plants using renewable energy sources have a much lower efficiency as compared to

the power plants using fossil fuels. Hence, the present invention, taking into consideration the environmental and efficiency issues, use an effective approach of using more than one energy source in the hybrid power plant so as to explore the strengths of some applications and address the weaknesses of other applications. Several attempts have been made to provide such hybrid power plant facilities.
A hybrid power plant comprising a first power plant which produces secondary steam of a first temperature and a second power plant that has an operating temperature higher than the first temperature is disclosed in WO2011028474. Steam at the first temperature is superheated to a higher temperature in the second power plant, wherein, the first power plant uses nuclear power, solar power, or biomass fuel and the second power plant uses fossil fuel.
Another hybrid power plant which combines a variety of renewable heat sources such as geothermal, solar, and biomass, with a fossil fuel furnace system is disclosed in US20100089060. The saturated steam generated by using the renewable heat sources is routed through the fossil fuel fired furnace where it is superheated.
Yet another hybrid power plant which uses both solar and non-solar energy sources is disclosed in US20070084208. The solar generating portion of the facility has a capacity to directly generate electricity from solar insolation or to store the solar energy in a tangible medium such as stored heat or solar fuel, The non-solar fuel based generating facility is provided adjacent to said solar fuel facility and comprises turbine-generator to generate electricity. The non-solar fuel based generating facility is powered, at least in part, by the solar fuel.

OBJECTS
Some of the objects in the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object in the present disclosure to provide a hybrid power generation system which uses renewable energy sources.
Another object in the present disclosure is to provide a hybrid power generation system having high efficiency.
Still another object in the present disclosure is to provide a hybrid power generation system which reduces the cost per unit of power.
Yet another object in the present disclosure is to provide a hybrid power generation system which substantially reduces CO2 emissions.
One more object in the present disclosure is to provide a hybrid power generation system proximal to a biomass source to reduce the transportation costs.
Yet one more object in the present disclosure is to provide a hybrid power generation system which utilizes energy efficiently to provide an uninterrupted operation 24/7.
Still one more object in the present disclosure is to provide a hybrid power generation system which is easy to control.

Other objects and advantages in the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with the present invention, there is envisaged a hybrid power generation system comprising:
■ at least one boiler feed pump for providing high pressure boiler feed water;
■ a plurality of boilers for generating superheated steam by boiling said high pressure feed water using renewable energy sources, wherein during operation at least one boiler is working and at least one boiler is stand-by, and the operation of said plurality of boilers being automatically controlled by means of a plurality of control valves provided in operative communication with plurality of control means;
■ a first steam turbine for receiving said superheated steam to generate energy and a steam condensate; and
■ an organic rankine cycle (122) comprising a second gas turbine (124), an evaporator (126) and a condenser (128), said evaporator (126) being adapted to extract heat from said steam condensate in a high pressure liquid refrigerant to generate high pressure refrigerant vapors, and said second gas turbine (124) being adapted to extract heat from said high pressure refrigerant vapors to generate energy.
Typically, in accordance with a preferred embodiment of the present invention, said plurality of boilers comprise a solar boiler and at least two biomass boilers.

Preferably, in accordance with the present invention, an accumulator is provided for storing said superheated steam.
Typically, in accordance with the present invention, a deaerator is interfaced with said boiler feed pump such that feed water to said boiler feed pump is supplied via said deaerator. Further, said deaerator is adapted to collect moisture from said superheated steam. Still further, a condensate tank is provided to collect condensate from said evaporator and subsequently convey to said boilers via said deaerator.
Preferably, in accordance with the present invention, said plurality of control means is a programmable logic controller.
Additionally, in accordance with the present invention, flow control valves are provided to control the flow rate of said superheated steam from said plurality of boilers.
Typically, in accordance with the present invention, said second gas turbine and said condenser are interfaced such that condensed liquid refrigerant leaving said second gas turbine is further condensed in said condenser and then pressurized to obtain said high pressure liquid refrigerant.
In accordance with the present invention, there is provided a method for generating energy using a hybrid power generation system, said method comprising the steps of: ■ providing high pressure boiler feed water by means of at least one boiler feed pump;

■ boiling said high pressure boiler feed water in at least one boiler to generate superheated steam, wherein a plurality of boilers are provided and during operation at least one of the plurality of boilers is working and at least one of the plurality of boilers is stand-by, the operation of said boilers being automatically controlled by means of a plurality of control valves provided in operative communication with plurality of control means;
■ expanding said superheated steam in a first steam turbine to generate energy and a steam condensate; and
■ receiving said steam condensate in an organic rankine cycle, where heat from said steam condensate is used to vaporize a high pressure liquid refrigerant in an evaporator and the high pressure refrigerant vapors are then expanded in a second gas turbine to generate energy.
The method, in accordance with the present invention, comprises selectively operating said plurality of boilers by continuously monitoring said superheated steam temperature. Further, the method comprises using solar energy as the prime source of energy and biomass as the secondary source of energy.
Typically, in accordance with the present invention, the method includes the step of collecting said superheated steam in an accumulator.
Preferably, in accordance with the present invention, the method includes the step of supplying the boiler feed water via a deaerator. Further, the method includes the step of deaerating said superheated steam. Still further, the method includes the step of conveying said steam condensate to said deaerator via a condensate tank.

Additionally, in accordance with the present invention, the method includes the step of controlling the flow rate of said superheated steam by means of flow control valves.
Typically, in accordance with the present invention, the method includes the step of further condensing a condensed liquid refrigerant leaving said second gas turbine in a condenser. The method further comprises pressurizing the further condensed liquid refrigerant to obtain said high pressure liquid refrigerant.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the non-limiting accompanying drawing, in which,
FIGURE 1 illustrates a schematic representation of the hybrid power generation system.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The present disclosure will now be described with reference to the accompanying drawing which does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The present disclosure envisages a hybrid power generation system that primarily uses renewable energy sources, typically solar power and biomass, to generate superheated steam which is subsequently received in a plurality of gas

turbines for expansion and generation of power. The system is provided with controllable valves in communication with programmable logic controllers so as to automatically manipulate the operation of the boilers as per the amount of solar energy harnessed.
Referring to FIGURE 1, therein is illustrated a schematic representation of the hybrid power generation system in accordance with the present disclosure, generally represented in the FIGURE 1 by numeral 100. The hybrid power generation system 100 comprises: a solar boiler 102, at least two biomass boilers (104a & 104b), boiler feed pumps (106a & 106b), a solar field 108, an accumulator 110, a deaerator 112, a first steam turbine 120, and an organic Rankine cycle 122 comprising a second gas turbine 124, an evaporator 126, a condenser 128, and pumping means 130.
The boiler feed pumps (106a & 106b) are adapted to pump feed water to a high pressure and feed the high pressure feed water to at least one boiler from the solar boiler 102 and the biomass boilers (104a & 104b). A deaerator 112 is interfaced with the boiler feed pumps (106a & 106b) such that the feed water to the boiler feed pumps (106a & 106b) is supplied via the deaerator 112. During sunny period, when good amount of solar energy is harnessed, the solar boiler 102 receives the solar energy via the solar field 108 and is adapted to utilize this solar energy to boil the pressurized water received by means of the boiler feed pumps (106a & 106b). During the sunny period, at least one of the biomass boilers (104a & 104b) is kept simmering under pressure so as to act as a stand-by boiler in circumstances when sufficient energy is not harnessed by the solar field 108. The function of the stand-by boiler is to respond to any variation in the solar energy without affecting the operation of the power plant

100. These biomass boilers (104a & 104b) use biomass material as fuel to generate steam. Thus, during the sunny period, one of the biomass boilers (104a & 104b) is connected in parallel to the solar boiler 102. Hence, during the sunny period, the power load is primarily managed by the solar boiler 102 and optionally by one of the biomass boilers (104a or 104b). During night time or monsoon time, when no solar energy is harnessed, the solar boiler 102 is put out of operation and the power load is managed by one of the biomass boilers (104a or 104b). During this time, the biomass boilers (104a & 104b) are connected in parallel to each other, however, only one of the biomass boilers (104a or 104b) is operational and the second biomass boiler is used only when the first boiler is put out of operation for maintenance purposes.
The operation of the solar boiler 102 and the biomass boilers (104a & 104b) is controlled by the control valves 114c, 114a & 114b respectively, after receiving signals from plurality of control means (programmable logic controllers) 116c, 116a & 116b respectively; wherein the programmable logic controllers (116a, 116b, & 116c) are provided in operative communication with the respective boilers (102,104a & 104b) to receive the steam temperature data and depending upon the steam temperature data, control the valves (114a, 114b & 114c) thereby controlling the operation of the system 100. The superheated steam generated in the boilers viz. 102,104a & 104b is then expanded in a first steam turbine 120 to generate power. The flow rate of the steam leaving the boilers viz. 102, 104a & 104b is controlled by the valves 118c, 118a & 118b, respectively. The accumulator 110 is provided in communication with the boilers viz. 102, 104a & 104b to accumulate heat energy when additional. This additional heat energy can be used to boil pressurized water received by means of the boiler feed pumps (106a & 106b). The operation of the accumulator 110

is controlled by the valve 114d by means of signals from programmable logic controller 116d. Further, the deaerator 112 receives any water from the superheated steam line, the deaerator 112 being adapted to separate the gases and return the water via an excess flow line through the boiler feed pumps (106a & 106b) to the boilers viz. 102, 104a & 104b.
The superheated steam is received in the first steam turbine 120 where the thermal energy from the pressurized steam is extracted to produce work/mechanical energy. This work is subsequently converted to useful electrical energy by means of a generator. The steam condensate leaving the first steam turbine 120 is received in the evaporator 126 of the organic Rankine cycle 122. The evaporator 126 is adapted to receive a high pressure liquid refrigerant. This high pressure liquid refrigerant extracts heat from the steam condensate to become high pressure refrigerant vapors. The condensate from the evaporator 126 is collected in a condensate tank 132 and subsequently pumped by pumping means 134 to the boilers viz. 102, 104a & 104b via the deaerator 112.
The high pressure refrigerant vapors are conveyed to the second gas turbine 124 where the thermal energy from the pressurized vapors is extracted to produce work/mechanical energy. This work is subsequently converted to electrical energy by means of a generator. The condensed liquid refrigerant from the second gas turbine 124 is passed through the condenser 128. The second gas turbine 124 and the condenser 128 are interfaced such that condensed liquid refrigerant leaving the second gas turbine 124 is further condensed in the condenser 128 and then pressurized to obtain the high pressure liquid refrigerant. In the condenser 128, the condensed refrigerant loses heat to a

cooling fluid to become the further condensed liquid refrigerant. This liquid refrigerant is then pressurized by the pumping means 130 to initiate a new thermal cycle.
TECHNICAL ADVANTAGES
The hybrid power generation system and method thereof, as described in the present disclosure has several technical advantages including but not limited to the realization of:
• using renewable energy sources;
• providing higher efficiency and easy to control and operate;
• reducing the cost per unit of power;
• substantially reducing C02 emissions; and
• providing uninterrupted operation 24/7.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
In view of the wide variety of embodiments to which the principles of the present disclosure can be applied, it should be understood that the illustrated embodiments are exemplary only. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principle of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

WE CLAIM;
1. A hybrid power generation system (100) comprising:
■ at least one boiler feed pump (106) for providing high pressure boiler feed water;
■ a plurality of boilers (102, 104) for generating superheated steam by boiling said high pressure feed water using renewable energy sources, wherein during operation at least one boiler is working and at least one boiler is stand-by, and the operation of said plurality of boilers being automatically controlled by means of a plurality of control valves (114) provided in operative communication with plurality of control means (116);
■ a first steam turbine (120) for receiving said superheated steam to generate energy and a steam condensate; and
■ an organic rankine cycle (122) comprising a second gas turbine (124), an evaporator (126) and a condenser (128), said evaporator (126) being adapted to extract heat from said steam condensate in a high pressure liquid refrigerant to generate high pressure refrigerant vapors, and said second gas turbine (124) being adapted to extract heat from said high pressure refrigerant vapors to generate energy.

2. The system as claimed in claim 1, wherein said plurality of boilers comprise a solar boiler (102) and at least two biomass boilers (104a, 104b).
3. The system as claimed in claim 1, wherein an accumulator (110) is provided for storing said superheated steam.

4. The system as claimed in claim 1, wherein a deaerator (112) is interfaced with said boiler feed pump (106) such that feed water to said boiler feed pump (106) is supplied via said deaerator (112).
5. The system as claimed in claim 4, wherein said deaerator (112) is adapted to collect moisture from said superheated steam.
6. The system as claimed in claim 4, wherein a condensate tank (132) is provided to collect condensate from said evaporator (126) and subsequently convey to said boilers (102, 104) via said deaerator (112).
7. The system as claimed in claim 1, wherein said plurality of control means (116) is a programmable logic controller.
8. The system as claimed in claim 1, wherein flow control valves (118) are provided to control the flow rate of said superheated steam from said plurality of boilers (102, 104).
9. The system as claimed in claim 1, wherein said second gas turbine (124) and said condenser (128) are interfaced such that condensed liquid refrigerant leaving said second gas turbine (124) is further condensed in said condenser (128) and then pressurized to obtain said high pressure liquid refrigerant.
10.A method for generating energy using a hybrid power generation system, said method comprising the steps of:

■ providing high pressure boiler feed water by means of at least one boiler feed pump;
■ boiling said high pressure boiler feed water in at least one boiler to generate superheated steam, wherein a plurality of boilers are provided and during operation at least one of the plurality of boilers is working and at least one of the plurality of boilers is stand-by, the operation of said boilers being automatically controlled by means of a plurality of control valves provided in operative communication with plurality of control means;
■ expanding said superheated steam in a first steam turbine to generate energy and a steam condensate; and
■ receiving said steam condensate in an organic rankine cycle, where heat from said steam condensate is used to vaporize a high pressure liquid refrigerant in an evaporator and the high pressure refrigerant vapors are then expanded in a second gas turbine to generate energy.
11. The method as claimed in claim 10, which includes the step of selectively operating said plurality of boilers by continuously monitoring said superheated steam temperature.
12.The method as claimed in claim 10, which includes the step of using solar energy as the prime source of energy and biomass as the secondary source of energy.
13.The method as claimed in claim 10, which includes the step of collecting said superheated steam in an accumulator.

14.The method as claimed in claim 10, which includes the step of supplying the boiler feed water via a deaerator.
15.The method as claimed in claim 14, which includes the step of deaerating said superheated steam.
16.The method as claimed in claim 14, which includes the step of conveying said steam condensate to said deaerator via a condensate tank.
17.The method as claimed in claim 10, which includes the step of controlling the flow rate of said superheated steam by means of flow control valves.
18.The method as claimed in claim 10, which includes the step of further condensing a condensed liquid refrigerant leaving said second gas turbine in a condenser.
19.The method as claimed in claim 18, which includes the step of pressurizing the further condensed liquid refrigerant to obtain said high pressure liquid refrigerant.