FIELD OF THE INVENTION

[0001] The present invention relates to the fields of power generation systems. The present invention specifically relates to an improved system for generating power using natural resources such as solar energy.

BACKGROUND OF THE INVENTION

[0002] Generally, utilization of solar energy by heat absorption is well known. There is an enormous amount of solar energy provided by the sun, which is available without significant environmental impact. This-solar energy is essentially free, in that it continually falls on the surface of the earth, especially a great deal of solar energy impinges on the earth's surface every day. Unlike other sources of energy, solar energy does not require exploration, extraction of materials or refining.

[0003] Conventionally, various types of power generation facilities are available to produce power using geothermal and engine exhaust. However, in such power generation systems, it is necessary to implement complex assemblies, very special handling structures and expensive operating plants for power generation. Moreover, these power generation systems requires sources such as fuel to produce heat for power generation, which results in high operating cost and also increases plant design and building costs.

[0004] Therefore, it is desirable to provide and develop an alternate and improved system for generating power using solar energy, which is capable to address and overcome the abovementioned disadvantages of conventional power generation systems. Such system should be simple and environmental friendly.

SUMMARY OF THE INVENTION

[0005] Accordingly, it is an object of the present invention to provide a system for generating power using solar energy, which is capable of generating power with minimal operating cost as there is no fuel needed to generate heat.

[0006] It is another object of the present invention to provide a system for generating power using solar energy, which is simple, cost effective and environmental friendly.

[0007] In accordance with one aspect, the present invention, which achieves the objectives, relates to a system for generating power using solar energy comprising a refrigerant pump configured to supply fluid under desired pressure and temperature. At least one solar collector is positioned to collect heat by absorbing sunlight. The solar collector is connected to the refrigerant pump, such that the pressurized fluid fed through the solar collector is heated and converted to pressurized low superheated vapor by inducing the collected heat into the pressurized fluid. A turbine is associated with the solar collector in such a way that the turbine is operated and driven by extracting thermal energy of the pressurized low superheated vapor from the solar collector. An electrical generator is coupled to the turbine such that the electrical generator is operated and driven by rotary motion of the turbine to produce electric power. A condenser is in fluid communication with the turbine and the refrigerant pump for receiving and cooling the low superheated vapor from the turbine in order to induce a phase change of low superheated vapor into the fluid, which is again recirculated to the refrigerant pump for repeating the power generation process. Such power generation system facilitates power generation with minimal operating cost as there is no fuel needed to generate heat. Moreover, it is simple, cost effective and environmental friendly.

[0008] Furthermore, the system comprises a subcooler placed in between the refrigerant pump and the electrical generator for cooling of the pressurized fluid from the refrigerant pump to lubricate bearings and cool a motor of the electrical generator by flowing the pressurized fluid into the electrical generator. The drain fluid from the electrical generator is fed into the condenser for cooling and recycling it to the refrigerant pump. The system also comprises at least one filter placed in between the refrigerant pump/subcooler and the condenser/electrical generator for filtering out debris in the fluid.

[0009] In addition, the solar collector acts as an evaporator to impart the collected heat into the pressurized fluid and to raise the temperature of the pressurized fluid to a desired range, preferably about 215° Fahrenheit with pressure of 183 psia. The solar collector is also configured to collect hot secondary fluid through a brazed plate or shell and tube evaporator on one side and the pressurized fluid on other side, such that the solar collector is operated at desired low pressure. The condenser includes a water-cooled condenser and an air-cooled condenser, whereas the fluid includes liquid refrigerant. The water- cooled condenser is fluid communication with a water pump and a cooling tower in such a way that water pumped from the water pump to the cooling tower cools the low superheated vapor by receiving thermal energy from it. The heated water in the condenser is collected by the cooling tower for cooling and circulating the water again to the water pump.

[0010] In accordance with another aspect, the present invention, which achieves the objectives, relates to a system for generating power using solar energy further comprising an additional subcooler arranged in upstream of the refrigerant pump and positioned between the condenser and the refrigerant pump for additional cooling of the fluid before pumping it to the refrigerant pump.

[0011] In accordance with further aspect, the present invention, which achieves the objectives, relates to a system for generating power using solar energy further comprising a preheater placed in between the condenser and the pump in such a way that return water is heated by inducing the rejected thermal energy from the fluid passing through the preheater. The return water is also conveyed from the preheater to the condenser for heating it again by inducing the rejected thermal energy from the fluid passing through the condenser.

[0012] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review .of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only, and not for the purpose of limiting the same.

[0014] FIG. 1 shows a schematic diagram of a system for generating power using solar energy, in accordance with an exemplary embodiment of the present invention;

[0015] FIG. 2 illustrates a schematic diagram of the system for generating power using solar energy having an additional subcooler in upstream of a pump, accordance with an exemplary embodiment of the present invention; and

[0016] FIG. 3 illustrates a schematic diagram depicting a combined hot water and power generation system using solar energy, in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0017] Referring to FIG. 1, a schematic diagram of a system for generating power using solar energy is illustrated, in accordance with an exemplary embodiment of the present invention. The present invention relates to an improved and economical system for generating power using solar energy, which is utilized in medium to large residential complexes and commercial establishment. Hereafter, the system can be referred as power generation system only for the purpose of explanation. The power generation system is arranged with a refrigerant pump (102), a solar collector (104), a turbine (106), an electrical generator (108), a condenser (110), filters (116a, 116b), an optional subcooler (118) and control or check valves (120a-120g). By using these components and scalability, the power generation system produces a significant amount of electrical power without requiring highly efficient, complex, expensive components to increase the system's efficiency. In some variations, however, higher efficiency components can be included if the economics of the application justify such components.

[0018] In this power generation system, the solar collector (104) is connected to the refrigerant pump (102) through conduits (122), such that the refrigerant pump (102) is directed to feed working fluid such as liquid refrigerant, to the solar collector (104) under desired pressure. The control valves (120a, 120b) are placed in the conduit (122) between the refrigerant pump (102) and the solar collector (104) for controlling the flow of liquid refrigerant. Hereafter, the working fluid is referred as liquid refrigerant, only for the purpose of explanation. The refrigerant pump (102) raises the liquid pressure before entering into the solar collector (104), where the liquid refrigerant exhibits pressure of 183 psia and temperature of 87" Fahrenheit, while entering into the solar collector (104). As the solar energy collector (104) is directed to collect heat by absorbing sunlight, the solar collector (104) acts as an evaporator to impart the collected heat into the pressurized liquid refrigerant. The solar collector (104) can be selected to be sufficient to raise the temperature of the liquid refrigerant to a temperature in desired range, for example range of about 215° Fahrenheit, and to induce a phase change of the refrigerant from liquid state to gaseous state. The liquid refrigerant fed through the solar collector (104) can be heated and converted to pressurized low superheated vapor having pressure of 183 psia and temperature of 215° Fahrenheit.

[0019] The solar collector (104) provides an increase in heat energy to the liquid refrigerant in the system to raise the temperature of or convert the state of the liquid refrigerant into the pressurized low superheated vapor. The solar collector (104) is associated with the turbine (106) through the conduits (122), such that the low superheated vapor from the solar collector (104) can be passed through the conduits (122) to drive the turbine (106). The control valve (120c) is placed in the conduit (122) between the solar collector (104) and the turbine (106) for controlling the flow of low superheated vapor. The turbine (106) extracts thermal energy from the pressurized low superheated vapor and converts it into rotary motion. The turbine (106) is coupled to the electrical generator (108) in such a way that the electrical generator (108) can be driven by the rotary motion of the turbine (106) to generate electricity power, which can be used in the residential and commercial complexes. The conduits (122) are in fluid communication with the components of the power generation system for conveying the liquid refrigerant through out the power generation system. The conduits (122) described herein include, but are not limited to hose or pipe. The conduits (122) are capable of transporting the liquid refrigerant at a desired pressure, preferably between 20 and 200 psia.

[0020] Furthermore, the refrigerant pump (102) discharges and feeds the pressurized liquid refrigerant to the generator (108) through an optional subcooler (118) for lubricating bearings and cooling a motor (not shown) of the generator (108). As shown in FIG. 1, the optional subcooler (118) is positioned in a bearing and motor feed line of the generator (108) via the filter (116a) and the control valve (120g) for further cooling of the liquid refrigerant from the refrigerant pump (102), which avoids flashing of the liquid refrigerant in the bearings due to the heat generated in the bearings. The filter (116a) is placed in between the subcooler (118) and the generator (108) for filtering out debris in the liquid refrigerant, which protects the bearings of the generator (108). The turbine (106) and the generator (108) are coupled to the condenser (110) through the conduits (122) and the control valve (102d). After cooling the motor and the bearings of the generator (108), the drain liquid refrigerant from a motor housing of the generator (108) is fed into the condenser (110), where it is cooled and recycled to the refrigerant pump (102).

[0021] Similarly, the hot exit gas from the turbine (106) is also fed into the condenser (110), where the condenser (110) includes, but is not limited to water- cooled condenser or air-cooled condenser. The hot exit gas and the liquid refrigerant exhibit pressure of 26.5 psia and temperature of 127° Fahrenheit, while entering into the condenser (110). Here, the condenser (110) is illustrated as water-cooled condenser only for the purpose of explanation, i.e. the water- cooled condenser and the cooling tower (114) can be replaced by the air-cooled condenser. In case of water-cooled condenser (110), the hot exit gas from the turbine (106) and the drain liquid refrigerant from the generator (108) can be passed through the condenser (110), where it can be cooled by pumping the water from a water pump (112) into the condenser (110). The water collects heat from the liquid refrigerant, which can be recirculated to the refrigerant pump (102) through the control valves (120e, 120f) and the filter (116b) that filters out debris in the liquid refrigerant to protect the refrigerant pump (102) from any foreign particles.

[0022] The condenser (110) is associated with a cooling tower (114), such that the heated water in the condenser (110) can be collected by the cooling tower (114), which cools and feeds the water again to the water pump (112). The condenser (110) induces a phase change in the working fluid from a gas phase to a liquid phase, i.e. the hot exit gas into the liquid refrigerant, by removing heat from the working fluid in the condenser (110). The condenser (110) can be selected in any suitable manner to remove sufficient heat to induce the phase change. After the liquid refrigerant is cooled in the condenser (110), the liquid refrigerant exhibits pressure of 25 psia and temperature of 85° Fahrenheit, while entering again into the refrigerant pump (102). Then, the refrigerant pump (102) again pumps and recycles the liquid refrigerant from lower pressure to higher pressure, preferably pressure of 183 psia and temperature of 87° Fahrenheit, and feeds to the solar collector (104) for continuous power generation. The power generation system is a closed system that periodically and continuously, cycles the liquid refrigerant or other working fluid through the system and uses heat from natural resources such as sun, for power generation, which minimizes overall operating cost as there is no fuel needed to generate heat. Moreover, it is simple, cost effective and environmental friendly.

[0023] FIG. 2 illustrates a schematic diagram of the system for generating power using solar energy having an additional subcooler (200) in upstream of a pump (102), accordance with an exemplary embodiment of the present invention. In this power generation system, an additional subcooler (200) is placed in upstream of the refrigerant pump (102), i.e. positioned in the conduit (122) between the condenser (110) and the refrigerant pump (102), which avoids cavitation in the power generation system. The subcooler (200) is configured to provide further cooling of the liquid refrigerant before transmitting it to the refrigerant pump (102) through the filter (116b). One variation is that the water- cooled condenser (110) described and illustrated in FIGS. 1 and 2 can be replaced by an air-cooled condenser system for cooling the liquid refrigerant in the power generation system. Another variation is that secondary fluid and evaporator system can be incorporated in the power generation system, as shown in FIGS. 1 and 2. In the second variation, the liquid refrigerant passes through the solar collector (104) for power generation. In addition, the liquid refrigerant can be combined with a secondary fluid such as water, to pass through the solar collector (104). In such case, the water passes through a brazed plate or shell and tube evaporator with hot water on one side and the liquid refrigerant on other side. It is advantageous that the solar collector (104) can be operated at low pressure of 30 to 40 psia, compared to 20 psia with organic fluid.

[0024] Referring to FIG. 3, a schematic diagram depicting a combined hot water and power generation system using solar energy is illustrated, in accordance with an exemplary embodiment of the present invention. In the combined hot water and power generation system, the pump (102) is in fluid communication with the solar collector (104) and the generator (108) for supplying the liquid refrigerant to the solar collector (104) and the generator (108) under pressure, preferably at the temperature of 20''C. The liquid refrigerant drawn into the solar collector (104) is heated using the sunlight heat received by the solar collector (104), such that the liquid refrigerant is converted into pressurized low superheated vapor, preferably at the temperature of 120°C. Then, the superheated vapor is conveyed to drive the turbine (106), which actuates and operates the electric generator (108) to produce electric power. The generator (108) also receives the liquid refrigerant from the pump (102) for cooling bearings and other parts of the generator (108).

[0025] Thereafter, the hot vapor from the turbine (106) and the hot refrigerant from the generator (108), which are preferably at the temperature of 60°C, are conveyed to the condenser (110). The condenser (110) is arranged to pass the cool return water in it for cooling and converting the hot vapor and the hot refrigerant into the liquid refrigerant, preferably at the temperature of 60X. A preheater (300) is placed in between the condenser (110) and the pump (102) in such a way that the liquid refrigerant from the condenser (110) is conveyed to the preheater (300), which enables the return water to be heated by passing it to the preheater (300), preferably at the temperature of 25°C, to receive rejected thermal energy from the liquid refrigerant. The return water passed in the preheater (300) is again conveyed to the condenser (110), where it is further heated by receiving the rejected thermal energy from the exitliquid refrigerant. Such heated water from the condenser (110) can be utilized for providing hot water for domestic use or any other applications. Then, the cooled, lower pressure liquid refrigerant is returned to the pump (102) to repeat the cycle to produce more electrical power.

[0026] The foregoing description is a specific embodiment of the present invention. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.

[0027] Other modifications will be apparent to those skilled in the art and, therefore, the invention is defined in the claims.

CLAIMS

1. A system for generating power using solar energy, comprising:
a refrigerant pump configured to supply fluid under desired pressure and temperature;
at least one solar collector positioned to collect heat by absorbing sunlight, said solar collector is connected to said refrigerant pump, such that the pressurized fluid fed through said solar collector is heated and converted to pressurized low superheated vapor by inducing the collected heat into the pressurized fluid; a turbine associated with said solar collector in such a way that said turbine is operated and driven by extracting thermal energy of the pressurized low superheated vapor from said solar collector; an electrical generator coupled to said turbine such that said electrical generator is operated and driven by rotary motion of said turbine to produce electric power; and
a condenser in fluid communication with said turbine and said refrigerant pump for receiving and cooling the low superheated vapor from said turbine in order to induce a phase change of low superheated vapor into the fluid, which is again recirculated to said refrigerant pump for repeating the power generation process.

2. The system for generating power using solar energy of claim 1, further comprising a subcooler placed in between said refrigerant pump and said electrical generator for cooling of the pressurized fluid from said refrigerant pump to lubricate bearings and cool a motor of said electrical generator by flowing the pressurized fluid into said electrical generator, wherein the drain fluid from said electrical generator is fed into said condenser for cooling and recycling it to said refrigerant pump.

3. The system for generating power using solar energy of claim 1, further comprising an additional subcooler arranged in upstream of said refrigerant pump and positioned between said condenser and said refrigerant pump for additional cooling of the fluid before pumping it to said refrigerant pump.

4. The system for generating power using solar energy of claim 1, further comprising a preheater placed in between said condenser and said pump in such a way that return water is heated by inducing the rejected thermal energy from the fluid passing through said preheater.

5. The system for generating power using solar energy of claim 5, wherein the return water is also conveyed from said preheater to said condenser for heating it again by inducing the rejected thermal energy from the fluid passing through said condenser.

6. The system for generating power using solar energy of claim 1, further comprising at least one filter placed in between said refrigerant pump/subcooler and said condenser/electrical generator for filtering out debris in the fluid.

7. The system for generating power using solar energy of claim 1, wherein said solar collector acts as an evaporator to impart the collected heat into the pressurized fluid and to raise the temperature of the pressurized fluid to a desired range, preferably about 215° Fahrenheit with pressure of 183 psia.

8. The system for generating power using solar energy of claim 1, wherein said solar collector is also configured to collect hot secondary fluid through a brazed plate or shell and tube evaporator on one side and the pressurized fluid on other side, such that said solar collector is operated at desired low pressure.

9. The system for generating power using solar energy of claim 1, wherein said condenser includes a water-cooled condenser and an air-cooled condenser, whereas the fluid includes liquid refrigerant.

10. The system for generating power using solar energy of claim 10, wherein said water-cooled condenser is fluid communication with a water pump and a cooling tower in such a way that water from said water pump cools the low superheated vapor and then the hot water from said condenser is cooled in said cooling tower to recirculate it to said water pump.