Abstract:
A power generation plant generates electrical power to be distributed to consumers via a power grid. The plant also provides some of the power to a fuel processing facility that provides fuel for the plant, and re-cycles the by-products of the power generation process to provide at least some of the resources the plant uses to generate the electrical power.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority from the Provisional U.S. Application having Ser. No. 61/078,128. The &#39;128 provisional application, which is entitled “Combined Heat, Ice, Power, and Steam System,” was filed on Jul. 3, 2008 and is expressly incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates generally to power generation plants, and particularly to power generation plants that re-capture by-products for use in generating their resources. 
       BACKGROUND 
       [0003]    The rising costs of energy are causing serious problems. For example, the cost of generating power for use in homes and businesses has soared because many power plants rely on crude oil to generate power. As most people know, crude oil is expensive and the cost continues to rise. There is little likelihood of relief from such high prices thanks to a weak currency and a strong global demand for crude oil. Additionally, there are many environmental concerns that are inherently involved with the use of crude oil. These include, but are not limited to, pollution and spills. 
         [0004]    One solution is to employ alternative fuels, such as ethanol, to power the generation plants. Ethanol burns cleaner, and thus, does not generate the same types of pollution concerns that crude oil does. Ethanol-based power generation plants, however, can still be costly. One way to reduce the costs is to re-capture some of the by-products of producing that energy and use it to provide resources for the power generation plant. 
       SUMMARY 
       [0005]    The present invention provides a system for a power generation plant that uses some of the by-products generated by the power generation plant to produce at least some of the resources it needs to generate electrical power. 
         [0006]    In one embodiment, the system comprises a generator subsystem, a hot-water subsystem, and a chilled-water subsystem. The generator subsystem receives a combustible fuel, such as ethanol, for example, from a fuel processing facility. A pump compresses the fuel and mixes it with another compressed gas, such as oxygen, before injecting the mixture into a generator. The generator then ignites the gas mixture and uses the expanding gasses to operate a turbine to generate electricity. 
         [0007]    The hot-water subsystem comprises a pair of heat exchangers. A first heat exchanger is connected to the generator and receives the hot exhaust gasses from the generator. The first heat exchanger uses the hot exhaust gasses to convert water received from the fuel processing center to steam, which is stored in a steam reservoir. A portion of that steam may be provided to the fuel processing center on demand, however, the remainder of the steam is carried through a second heat exchanger. Using water received from the fuel processing facility, the second heat exchanger converts the steam to hot water for storage in a hot water reservoir. 
         [0008]    A portion of the hot water in the reservoir is provided to the fuel processing facility on demand. However, the remainder is used by the chilled-water subsystem to produce chilled water for use at the fuel processing facility. The chilled-water subsystem comprises a refrigeration unit having an ice bank. A compressor uses the hot water in the hot water reservoir to maintain the ice in the ice bank in a frozen state. A conduit extends through the ice bank and carries water from the fuel processing facility. As the water travels through the conduit in the ice bank, the ice chills the water. The chilled water is then returned to the fuel processing facility through the conduit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a block diagram illustrating a power generation system configured to recapture by-products according to one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    The present invention provides a system and method of re-capturing some of the by-products produced by generating energy. As seen in  FIG. 1  and as discussed in the specification, the system that re-captures the by-products is associated with an ethanol-based power generation plant that produces ethanol for fuel. However, this is for illustrative purposes only. The present invention may be used to re-capture and process by-products from other types of power generation plants as well. 
         [0011]      FIG. 1  is a block diagram illustrating an ethanol-based power generation plant configured according to one embodiment of the present invention. According to the present invention, the power generation plant is equipped with a Combined Heat, Ice, Power, and Steam (CHIPS) System  10  that re-captures the high heat-exhaust gasses that are produced by burning the ethanol for power, and converts these gasses to hot and cold water for use in an ethanol processing facility  12 . 
         [0012]    As seen in  FIG. 1 , the CHIPS system  10  comprises a plurality of conduits that interconnect a pump  14 , a Gas Turbine Generator (GTG)  16 , a High Temperature Heat Exchanger (HTHE)  18 , a steam reservoir  20 , a variable pressure regulating valve  22 , a thermostatic control valve  24 , a Low Temperature Heat Exchanger (LTHE)  26 , a hot water reservoir  28 , a Heat Absorption Chiller (HAC)  30 , and an ice bank  32 . 
         [0013]    The ethanol processing facility  12  produces ethanol from biomass using methods well-known known in the art. The pump  14  then pumps the ethanol from the processing facility  12  to the GTG  16  at high pressure. Specifically, the pump  14  receives the ethanol at a high volume, but pumps the ethanol to the GTG  16  at a much lower volume. This volume differential compresses the ethanol for delivery to the GTG  16 . 
         [0014]    The GTG  16  generally comprises three main components—a variable atomizer  16   a , a combustion chamber  16   b , and a turbine  16   c . The variable atomizer  16   a  mixes the high pressure compressed ethanol together with compressed oxygen and injects the mixture into the combustion chamber  16   b . Mixing the ethanol and the oxygen at the variable atomizer  16   a  creates high temperatures within the combustion chamber  16   b , and produces a high air velocity to the fans in turbine  16   c . The mixture is ignited within the combustion chamber  16   b , and the resulting gasses are directed over the fans in the turbine  16   c  causing them to spin. As is known in the art, the turbine  16   c  rotates a shaft, for example, to mechanically generate electricity. The electricity is provided back to the ethanol processing facility  12  to provide for its power needs. All excess power is provided to an external power grid for sale to providers to power homes and businesses. 
         [0015]    The GTG  16  produces high heat exhaust gasses. Typically, the temperature of the exhaust gasses is about 1500° F. Rather than allow these hot gasses to exhaust directly to the outside, however, they are captured and filtered by High Temperature Heat Exchanger (HTHE)  18  to produce superheated steam. In one embodiment, the HTHE  18  comprises a flue that exhausts to the exterior of the power generation plant. A coiled pipe  18   a  extends through the interior of the HTHE  18  and carries water produced by the processing facility  12 . The hot exhaust gasses enter the HTHE  18  from the GTG  16  and heat the water running through the coil  18   a  to convert it to steam. The exhaust gasses are filtered and vented to the outside. 
         [0016]    The steam produced by the HTHE  18  has a temperature of about 800° F., and is stored in a high pressure steam reservoir  20 . A portion of the steam is supplied on demand to the processing facility  12  via one or more variable pressure regulating valves  22 . The other portion of the captured steam, however, is diverted to a closed loop Low Temperature Heat Exchanger (LTHE)  26 . The LTHE  26  uses the steam to produce hot water via pressure regulating valves and temperature control devices. 
         [0017]    More particularly, a thermostatic control valve  24  is disposed between the steam reservoir  20  and the LTHE  26 . The valve  24  modulates the flow of steam coming from the steam reservoir  20  such that the average temperature of the steam entering the LTHE  26  is about 350° F. The heated steam travels through a coil  26   a  and returns to the steam reservoir  20  in a closed loop. Water from the processing facility is pumped into the LTHE  26  such that it flows around the heated coil  26   a . This heats the water such that the LTHE  26  outputs hot water at about 210° F. The hot water is stored in the hot water reservoir  28  and used on demand in the process facility  12 . All excess hot water, however, is directed to the Heat Absorption Chiller (HAC)  30 , which is designed to keep ice in the ice bank  32  frozen. 
         [0018]    More particularly, the HAC  30  is a refrigeration system that utilizes a heat source to provide the energy needed to drive a cooling system instead of electricity to drive a compressor. In  FIG. 1 , hot water from the hot water reservoir  28  provides the heat source and the ice bank  32 , which is full of ice, is the cooling system. In operation, the HAC  30  keeps the ice in the ice bank  32  frozen. Warm water provided by the ethanol processing facility  12  is run through the ice bank  32  to be chilled. The resultant chilled water is then returned to the processing facility  12  for use in the production of ethanol. 
         [0019]    By way of example, one embodiment of the present invention runs ammonia through the HAC  30  in a closed loop. The hot water flows around the ammonia-filled tube (not shown) and causes the ammonia to evaporate within the tube. The tube, however, extends from the HAC  30  into the ice bank  32 . Therefore, as the tube enters the ice bank  32 , the evaporated ammonia within the tube condenses back to a liquid and flows out of the HAC  30 . This removes the heat from the ice in the ice bank  32  and keeps the ice in the ice bank  32  frozen. Warm water provided from the processing facility  12  travels through a coil  32   a  that extends through the ice bank  32 . The ice in the ice bank  32  removes the heat from the warm water so that chilled water is pumped back to the processing facility  12  to provide for its cooling needs. 
         [0020]    The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.