BRPI0907973A2 - hybrid power plant - Google Patents

Abstract

"hybrid power plant" A hybrid power plant is described in which a pressurized water nuclear reactor or a biomass-powered power plant that has a relatively low operating temperature as such is combined with a coal-fired or other power plant. fossil fuel that has a higher operating temperature. Steam from the first plant is overheated at the second power plant to provide a hybrid plant with improved efficiencies and lower emissions.

Description

“HYBRID ENERGY PLANT” Fundamentals of the Invention

The present invention relates generally to nuclear power plants and, more specifically, to a hybrid power plant that combines a nuclear power plant or a biomass powered power plant with a fossil fuel power plant to provide greater lower efficiencies and emissions.

The vast majority of energy production in the world comes from one of four non-renewable sources: coal, gas, oil or nuclear. According to the most recent data (CY 2006) from the International Energy Agency, 85% of electricity was generated from nuclear sources (23.2%) and fuels (61.8%), while hydroelectric sources were 13.4% % and other renewable sources was 1.6%. Each of these sources has its advantages and disadvantages. Data only from the United States of the US Department of Energy divide fuels such as coal 49.7%, natural gas 18.7% and oil 3%. Petroleum is almost always reserved for transportation and is not normally used in electricity generation. Natural gas is used, but because of its cost, it is normally used only for peak energy surge capacity. This leaves nuclear and coal-fired power plants to provide the basic charge and most of the electricity in the world.

Coal currently provides the vast majority of the electricity generation capacity of the basic load and about half of all capacity, but its use is under great pressure due to pollution problems and especially carbon dioxide greenhouse gas emissions. Nuclear use has been limited by high production costs, largely driven by the very low thermal efficiency of its steam cycle, which requires a very large reactor in relation to the amount of electricity that can be generated because of its low temperature saturated steam.

Biomass has been investigated, but due to the high water content and low energy density it is not possible to reach combustion temperatures comparable to coal combustion. This results in lower efficiencies of low temperature saturated steam, much like those that limit nuclear energy.

Current applications for addressing environmental and efficiency problems center on multi-purpose installations. These facilities use a single source of energy to meet diverse needs, many by exploiting synergies between emissions control and residual energy or unused combustion products. This patent proposes a more effective approach for installing multiple uses, using more than one energy source in a hybrid power plant to use the advantages of separate technologies to address secondary disadvantages. A hybrid plant combining existing technologies from nuclear power plants or biomass power plants interconnected to a modified coal plant would result in a total thermal process that would have a greatly improved thermal cycle, thereby increasing electrical output by almost twice the same sets of inputs, compared to 'independent' configurations, thereby drastically reducing cost, pollution and carbon dioxide emissions compared to the two independent plants for these projects.

Coal-fired fossil fuel plants generally operate at maximum levels of thermal efficiency, with the electrical output to heat unit input fractions in the range of 30-45%. This is achieved through a three-step steam cycle. First, the boiler feedwater is preheated with the low temperature flue gas extraction steam to increase the condenser temperature to approximately 450 - 500 ° F (232 - 260 ° C). Once the feed water is added to the boiler, it is heated and converted to saturated steam at temperatures of 500 - 600 ° F (260 - 316 ° C). Once the steam is formed in the boiler, it passes through superheat tubes in the hottest section of the effluent gas column where the steam is raised to 1,100 ° F - 1,200 ° F (593 - 650 ° C). This superheated steam then passes through a series of high, intermediate and low pressure turbines, where energy is extracted and electricity is produced by generators mechanically attached to the turbines. A final step in a coal-fired power plant process for generating electricity is that the air being drawn into the furnace passes through the lower temperature effluent gases to preheat incoming air and increase the combustion temperature.

A coal-fired plant is very efficient, but even in this type of plant, most of the combustion energy is lost. Of the 1,512 BTUs (1595.2 kJ) required to heat one pound (0.45 kg) of 140 ° F (60 ° C) ambient feed water to one pound (0.45 kg) of superheated steam at 1,200 ° F ( 650 ° C), steam at 1,000 psi (6.89 MPa), 1,014 BTUs (1069.8 kJ) or 67% of the input energy goes into converting water to steam and cannot be recovered as an electrical outlet. Approximately another 40 BTUs (42.2 kJ) (about 3% of the total) are also irretrievably lost in each cycle. The condensers downstream of the turbines will operate at a vacuum, so that the steam will not convert back to water at the normal boiling point 212 ° F (100 ° C), but at a temperature of 140 ° F (60 ° C). However, this water will continue to cool until the temperature of the river or lake that is being used as the heat sink, and this heat will have to be replaced in the next cycle. Useful energy (for conversion to electricity) can be extracted from 1,200 ° F (650 ° C) steam to 140 ° F (60 ° C) steam. This means that less than one in two tons of carbon dioxide that a coal-fired power plant emits into the atmosphere is never used to produce electricity.

The use of biomass instead of coal in a boiler requires a configuration very similar to that of a pulverized coal boiler, although the operation of the plant is changed. Although there is a “zero liquid” carbon emission from these facilities, biomass has a lower energy density and flame temperature than coal when burned under the same conditions. This reduces the amount of energy that can be transferred to the feed water, reducing the steam temperature normally to steam not more than 850 F (454 ° C). Due to a lower operating temperature, a lower operating pressure is used to increase the efficiency of the cycle, so an operating pressure of 850 psi (5.9 MPa) is considered. This is a heat addition of 1,317 BTUs (1395.5 kJ) per pound (0.45 kg) in ambient feed water, of which approximately 1,014 BTUs (1069.8 kJ) are lost due to the phase change of steam to water and other losses. This means that 77% of the energy is not available to produce electricity.

The cutting edge technology of today's nuclear power plants (including pressurized light water reactors, boiling water reactors, and CANDU heavy water projects) is extremely stable, safe and emission-free. Its electrical output is extremely restricted, however, due to the need to limit the maximum temperature in the reactor core to approximately 600 ° F (316 ° C) (boiling water reactors operate at lower core temperatures of around 540 - 550 ° F ( 555 - 561 ° C)) to prevent loss of refrigerant and damage to fuel elements. This results in a plant with a very oversized reactor and loss of a high percentage of BTUs (1.06 kJ) generated. This results in excessive thermal pollution - the localized heating of the bodies of water that serve as heat sinks for the condensers of the steam turbine units.

The nuclear power plant has only two or three stages of the steam cycle. Essentially no overheating is added to the steam cycle, as the water in the steam generator is already in contact with the hotter water that passes through the reactor. There are methods of preheating the feed water that enters the steam generator, but this is done only with extraction steam, requiring a higher flow of steam for the same electrical outlet. The primary coolant water in contact with the reactor core heats up to 600 ° F (316 ° C) before going to the steam generator (the same function as the boiler in the coal-fired plant) and converting secondary water into steam at about 575 ° F (302 ° C) with an operating pressure of 400 psi (2.76 MPa) to increase efficiency. This results in a steam cycle where only 1,199 BTUs (1265 kJ) can be added for every pound (0.45 kg) of steam, also the same 1,014 BTUs (1069.8 kJ) are lost when changing water in / from steam, so that 85% of the thermal energy input can never be used to create electrical energy. By combining the highest temperatures obtainable in a coal oven with the low temperature steam from a nuclear or biomass installation, greater efficiency can be achieved with less emissions compared to any project alone.

Research on the prior art was conducted and the following related patents were discovered. None of these patents provides or suggests any method or device that corresponds to this invention.

U.S. patent 3,575,002 to Vuia was for a project that routed saturated steam from a standard nuclear power plant through the superheat section of a fossil fuel furnace in a conventional power plant. Although it is a viable solution, most of the energy input to the system is from coal, as this is a commercial scale fossil fuel power plant with a slightly larger section of the superheater in the furnace. This Vuia project proposes a design with two independent power plants in which the nuclear installation is assisted by the coal plant. On the contrary, this invention proposes a single integrated hybrid power plant that uses coal energy only to add superheat to the steam, decreasing the amount of coal used to generate the same amount of energy.

U.S. patent 4,530,814 to Schluderberg uses the thermal energy of a fossil-fueled plant to produce steam. This steam is then routed through a moisture separator / reheater unit to add steam that has already been expanded through a high pressure turbine. This design uses fossil fuel exclusively to add superheat to the steam from the nuclear process, but only does this indirectly and only after the vapor pressure has been reduced. In this design, the steam from the power plant drains out again, remains separate and the coal plant only provides a reheat to assist the nuclear power plant, and no energy is available to preheat the feed water.

Miller's U.S. patent 5,361,377 describes the use of superheaters before the high pressure turbine and in the moisture separator / reheater section between turbines. The described superheater can receive energy from both fossil fuel combustion and steam from an adjacent fossil fuel plant. The description is not clear how the superheater could use both steam and fossil fuel. The design also fails to make full use of the exhausted combustible gases to preheat the feed water and the combustion air, indicating that it is a small burner unit and not a full-size coal-burning furnace. It appears that this design concerns only a superheater heated to the extreme in a nuclear power plant.

U.S. patent 5,457,721 to Tsiklauri uses a combined cycle system with the hot exhaust gases from a gas turbine unit powered with natural gas that heats feed water and produces steam. The steam from this heat recovery steam generator is then used to overheat the steam from a nuclear powered steam generator. After the steam is expanded in the high pressure turbine, the two fluid streams are mixed and increased by more steam from the heat recovery steam generator and used in the low pressure turbine. This use of a heat recovery steam generator decreases the efficiency of the system, as opposed to using all energy to increase overheating. Mixing the steam from both sources decreases this loss of efficiency, but would require stricter controls on the chemical composition of the water.

U.S. patent 6,244,033 to Wylie uses the exhaust from a gas turbine unit powered with natural gas to directly overheat steam from a nuclear steam generator. It also makes use of the exhaust gases to preheat the feed water and provides an additional firing unit to ensure that there is enough energy to provide overheating and preheating. Notable in this patent is that it specifies that overheating and preheating can be added by using additional natural gas heat alone, if the gas turbine unit is not in operation. There is no provision for the use of coal in this patent, but only more expensive natural gas.

Summary of the Invention

The present invention, in a preferred embodiment, takes the saturated steam output from a nuclear power plant and passes it through a modified coal-fired plant boiler, and then the superheated steam produced from the coal plant is sent to the turbines where energy is extracted and converted into electricity. The nuclear power plant would be changed only minimally in relation to the existing drawings, the only revision in the drawing would be to increase the size of the steam generators by about 15% in relation to the size of the reactor core, since the feed water would be preheated to about 450 ° F (232 ° C) before entering the steam generator, so that the heat from the reactor would be used almost exclusively for converting water to steam, rather than heating the water as it does conversion to steam. In an alternative embodiment, a biomass-powered power plant takes the place of the nuclear power plant to supply steam to the modified coal-fired power plant.

Although this patent is applicable to any coal-fired oven, a pulverized coal design is described here to show the utility of this invention. The coal-fired unit would be modified more significantly, since the steam boiler section (the intermediate temperature section of the current design) would be eliminated. The section of the unit's superheat tube would be greatly expanded to accept saturated steam from the reactor and increase its temperature considerably before sending the superheated steam out of the turbines. In the furnace, tubes where effluent gases pass above 800 ° F (427 ° C) would be used to overheat the steam produced in the reactor, while tubes in the area where effluent gases are below 800 ° F (427 ° C) would be used to preheat feed water. Considering that the maximum temperature in the furnace is about 2,000 ° F (1,366 ° C), about 75% of the heat would go to superheat saturated steam to 575 ° F (302 ° C) for steam superheated to 1,200 ° F (650 ° C), while the remaining 25% would go in the direction of pre-heating the feed water before entering the reactor. This would result in a coal-fired plant half its original size and a quarter of its original carbon dioxide emissions for the same electrical outlet. We built our economical models with the assumption that the ideal solution would be to build the furnace to operate around 2,000 ° F (1,366 ° C) and use normal materials in the design of the superheat tubes. We realized that there is an alternative approach to using more exotic and higher-cost materials in the manufacture of tubes and increasing operational efficiency through higher temperatures to replace higher-cost materials. We intend this patent to cover both approaches.

When the nuclear side is taken into account, the electricity produced for any given reactor size would increase its independent output by at least 3 times. This would be the result of a 15% increase in the saturated steam generated as a result of the additional preheating of the feed water in the fuel plant's economizer, as well as the addition of coal overheating. Overheating the steam in the coal-fired unit would add 316 BTUs (333.4 kJ) recoverable to the 181 that existed when the steam left in the nuclear facility, for an increase of 175%. The sum of 115% of the volume of saturated steam times the 275% addition of superheat results in 3.16 times the production of energy. Another factor is that turbines that use superheated steam are more efficient than those that operate with saturated steam, so that an additional increase in electrical output can be obtained.

Nuclear power plants have historically been built with multiple units at individual sites. Of the 63 active sites for nuclear power stations in the United States, 37 have or have had two or three reactors, although only 26 have been built as individual reactor sites. In Canada, there are two sites with four active reactors (each planned for eight) along with a site with two reactors and a single isolated site with a power plant. Most plants are built in close proximity to a lake or river to provide a cooling source for the condensers. There is also a need for rail access to provide an economical means of providing the coal supply for the fossil fueled portion of the plant. These needs are not restrictive, as most railway lines follow river beds to avoid significant turns.

Similar benefits can be achieved in biomass powered power plants, with an additional 194 BTUs (204.7 kJ) of recoverable energy per pound (0.45 kg) of feed water. This would be combined with more efficient steam turbines to give an efficiency increase of over 55%. Furthermore, this design would require less biomass to generate the same amount of electricity, allowing most of these power plants to be put into service for a given fuel source.

Brief Description of Drawings

Figure la is a schematic diagram showing the feed water and steam temperatures of an exemplary independent nuclear reactor, and figure 1b is a schematic diagram of a hybrid power plant of the present invention in which the reactor in figure la has been combined with a coal-fired power plant.

Figure 2a is a schematic diagram of the main elements of an exemplary independent nuclear power plant, and figure 2b is a schematic diagram of the main elements of an exemplary independent coal-fired power plant.

Figure 3 is a schematic diagram corresponding to figure 2, in which the power plants have been modified and interconnected to form a hybrid power plant of the present invention.

Figure 4 is a graph of the energy content of the steam for the power plant described in this report. The enthalpy values are shown for 400 psi (2.76 MPa); the energy content is further increased with the use of higher pressure systems. This figure shows the additional useful energy that can be extracted from the steam using the present invention.

Figure 5 is a statistical table comparing the annual electrical output, annual costs and annual emissions of two independent nuclear reactors and an independent coal-fired plant versus a hybrid power plant of the present invention in which the two nuclear plants were interconnected at the plant coal-fired according to the present invention.

Figure 6 is a schematic diagram of an exemplary independent sprayed water nuclear reactor.

Figure 7 is a schematic diagram corresponding to figure 6 in which the pressurized water reactor has been interconnected to a coal-fired plant in accordance with the present invention.

Figure 8 is a graph that compares the three economic examples presented in this application and shows a surprising consistency of efficiency improvements inherent in the present invention.

Description of the Invention

Example 1 - Scheme of the hybrid power plant

In this example, a dedicated pressurized nuclear water reactor (figures la and 2a) is interconnected to an independent coal-fired power plant with the boiling section replaced by an extended superheater (figure 2b), forming the hybrid power plant represented in figure lb and figure 3.

Example 2 - General Cost Estimation and Emission Reductions

A general estimate of the cost and emission reductions can be made by examining the addition of a coal oven to the two existing nuclear power plants. Consider two 1,190 MW nuclear power plants that are interconnected to a coal-fired power plant sized to supply 1,075 MW if it had been designed as an independent unit. Following the graph in figure 4, and the assumptions provided in the figures, the statistics of annual energy production, annual operating costs and annual emissions are presented in figure 5. It can be seen that, when interconnected in accordance with the present invention, these three units, which would have a capacity of 3,455 MW if designed and operated as independent units, would have a capacity of 5,930 MW. This results in a reduction of around 36% in the cost per kilowatt of electricity produced and a reduction in carbon emissions of around 80%.

Example 3 - Detailed Cost Estimation and Emission Reduction

To show the economic and environmental benefits of this concept, this example builds on existing facilities. For this comparison, a baseline model for a pressurized water reactor power plant was modeled to allow comparison. Wolf Creek Nuclear Generating Station [Black & Veatch] data and operating parameters are used to develop the model. This comparison can also be extended to a facility powered by biomass and coal with appropriate parameters.

The Wolf Creek Nuclear Generating Station used is a 1,190 MW power plant in Burlington, KS. The project is a Westinghouse 4-circuit pressurized water reactor (PWR) plant. Among other details, a moisture separator / reheater and seven closed feed water heaters are used in the secondary steam system to increase efficiency. The plant operates as a saturated steam Rankine cycle, so there is no overheating of the steam from the steam generators.

During steady state of operation, the reactor is used to heat the primary refrigerant, which, in turn, is used to heat the secondary refrigerant, causing it to boil. Circulation in each primary refrigerant circuit is provided by a reactor refrigerant pump. The saturated steam produced in the steam generating units is delivered through the pipeline to an intermediate pressure turbine, where a certain amount of work is produced. After leaving the intermediate pressure turbine, the steam passes through a moisture separator to dry the steam to prevent damage to the turbine. The steam then passes through a low pressure turbine, where the rest of the available energy is extracted. A condenser at the outlet of the low pressure turbine condenses the steam (now called feed water) so that it can be pumped back into the steam generator using condensate pumps and feed pumps. This condensed steam passes through seven closed feed water heaters (CFWH) on the way back to the steam generator: four between the condensate pumps and feed pumps and three between the feed pumps and the steam generator. These CFWHs are heat exchangers that use steam extracted from different stages of the turbines to preheat the feed water before it returns to the steam generator. This redirects part of the energy back to the steam generator, instead of discarding it in the condenser, thereby increasing efficiency. CFWHs before the feed pumps drain into the condenser, while those after the feed pumps drain into a common tank, from which they are taken back to the system at the inlet to the feed pumps using a separate drain pump.

Some simplified assumptions were made in modeling this plant. The system is modeled in a steady state condition. The condenser pressure is considered 1 psia (6.89 kPa abs.), Pressure losses in the pipeline of 1% were applied through the system, and a pressure of 2% was used through the moisture separator. Furthermore, 15% of the emergy produced was considered a loss to account for generator losses and parasitic loads from the power plant, such as cooling water circulation pumps, high pressure air system and water treatment facilities. . As these assumptions are applied to both power plants, there should be no introduction of bias errors.

Option 1 - Keep the electrical output constant

Converted to BTUs (1.06 kJ) per hour, the electric output of 1.19 MW is 4.06x10 ⁹ BTU (428.3 x 10 ⁹ kJ) / h. To generate this electrical output is required l reactor power output, 375xlO ¹⁰ BTU ⁽¹⁰ kJ 1.45 x IO) / hr, giving an 29.5% plant efficiency. Figure 6 gives a schematic diagram of this system. For the sake of simplicity, only one circuit is shown in the figure.

The hybrid installation model was developed from the model of Wolf Creek Generating Station. The main changes were the insertion of a coal-fired oven to act as a superheater and economizer, and the elimination of the moisture separation unit. The moisture separator is unnecessary, as steam must maintain a sufficient amount of overheating in most steam turbines. These changes can be seen in the schematic diagram of the hybrid power plant (Figure 7).

Some changes also needed to be made to the system parameters to account for the addition of energy from coal. The outlet temperature of the superheater is considered 1,200 ° F (650 ° C), which is comparable to steam outlet temperatures from a modern coal oven. This built-in equipment is considered to cause a 4% decrease in pressure in the vapor flow because of friction losses. However, the 600 ° F (334 ° C) rise in steam temperature overcomes this pressure drop.

The use of the economizer increases the temperature of the feed water before it enters the steam generator, decreasing the amount of energy that needs to be added by the main circuit. This heat is added by the flue gases that leave the oven at a very low temperature to add overheating to the steam, and so this reuse of energy increases efficiency. This addition of extra heat from both the superheater and the economizer requires a change in the operating parameters of the closed-circuit water heaters, since the steam delivered by them has a higher thermal content and less heat needs to be added. As a result of the economizer and changes in the CFWHs, the feed water enters the steam generator at a temperature 80 ° F (27 ° C) higher than in the traditional PWR plant. A pressure loss of 2% has been added to the economizer to take into account the extra energy required to pump feed water through the heat exchanger tubing.

The only change in assumptions for the hybrid plant model compared to the traditional plant is that three percent more of the turbines' electrical energy is considered a loss. This is a conservative estimate that takes into account additional parasitic loads, such as induced drag fans, coal mills and other auxiliary systems associated with the coal fuel system.

To produce the same 1.19 MW of electricity as the traditional project, the hybrid installation required 6.951x10 ⁹ BTU (7.33 x 10 ⁹ kJ) / h from the reactor, 50.5% of the energy input of the basic reference project . An addition of 4.591x10 ¹⁰ BTU (4.84 x 10 ⁹ kJ) / h of coal is also required to drive the superheater, for a total heat input of 1.154x10 ¹⁰ BTU (1.22 x ^{10 10} kJ) / h. The plant's efficiency for this system is calculated in

35.5%. Considering a higher heating value (energy content) of 10,000 BTU (10550 kJ) / lbm (0.45 kg) for coal and a cost of $ 40 per ton delivered, the cost per kilowatt hour attributed to coal at a power plant. hybrid energy is $ 0.00452.

Option II - Keep the reactor output constant, increase the electrical output

If the primary nuclear facility were left as it is, the facility's rating would be lowered by the addition of coal-fired superheaters. This would increase the plant's production from the original 1,190MW to 2,354MW. Keeping the size of the reactor plant the same, the capital cost to build the plant and operating costs would remain virtually the same for reactor systems, increasing electrical production by almost 98% by incorporating a coal-fired superheater and the ability of the additional turbine to accommodate the increased flow of steam. Using the same cost assumptions, this would lead to a cost of $ 0.01011 per kWh compared to the nuclear facility. Again using the previously calculated value of $ 0.00452 per kWh for coal energy in a hybrid installation, this gives an overall cost of $ 0.01463 per kWh. These savings of $ 0.00537 per kWh represent savings of more than 25% for electricity production at the power plant, while virtually doubling capacity.

A detailed comparison shows that, for the same electricity generation, only 84.7% of the thermal energy input from a traditional project is needed for a hybrid installation. Furthermore, there is 25.8% less heat discharged in the condenser. These values are reflected in the greater efficiency of the plant.

Conclusions

The hybrid installation provides a thirty-six percent increase in efficiency, an increase of approximately 3% for biomass and 6% for nuclear plants alone. The increase in efficiency is directly related to the higher temperature of the steam delivered by the coal-fired superheater, increasing the Camot (or maximum) efficiency that the system can obtain. Using coal to add superheat to the steam, a large part of the coal's energy is converted into electricity.

As an example, the smaller amount of energy that needs to be added by the reactor system would lower the cost of the nuclear installation.

The 50% decrease in fuel costs (about 15% of the total cost) and the use of a six-tenth rule for capital, operation and other costs (the remaining 85%) to decrease them by 33%, reduction of the total cost for electricity generation with the nuclear installation is decreased in

35.55%. Although this does not include the capital cost of the coal-fired oven, the economy is expected to offset this cost in the short term. Although this configuration has carbon emissions, they must be much smaller than a conventional coal installation. Considering that no overheating of the nuclear portion of the plant was added, the only energy from coal not converted into electricity would be losses, cutting carbon emissions by one third. When the greater steam flow due to the preheating of the feed water is also taken into account, it would be possible to achieve a carbon reduction of about 75% compared to an independent coal plant.

There is also the potential to add sufficient preheating to the feed water in the economizer to make use of unnecessary feed water heaters. This would reduce the amount of steam flow needed to produce the same amount of electricity and possibly increase the plant's overall output.

The only potential physical limitation for this invention is how to maintain the oven temperature which is sufficient to add superheat to the steam without damaging the tubes of the superheater. This should be possible by controlling the amount of oxygen introduced into the fuel during combustion, or by selecting the fuel.

The proposed project results in both a more efficient plant and a lower cost per kWh to produce electricity. Taking all of these factors into account, the models presented here show that the performance benefit of using a biomass or nuclear energy combination to produce steam and coal energy to add overheating has the potential to be economically viable, as well as significantly more efficient.

Although the examples presented were limited to a combination of nuclear or biomass power plants with coal-fired power plants, the invention also includes a hybrid power plant where a pressurized water reactor is combined with a pebble bed reactor . As with the coal-fed mode, the steam from the pressurized water reactor is used as a source of preheated steam for the pebble bed reactor to achieve greater efficiencies.

The description and drawings presented comprise illustrative modalities of the present inventions. The modalities presented and the methods described here may vary based on the skill, experience and preference of those skilled in the art. The mere listing of the steps of the method in a certain order does not constitute any limitation regarding the order of the 15 steps of the method. The description and drawings presented merely explain and illustrate the invention, and the invention is not limited to this, except to the extent that the claims are thus limited. Versed in the technique that, in possession of this revelation, they will be able to make modifications and variations in them without escaping its scope.

Claims (3)

1. Hybrid power plant, characterized by the fact that it comprises: (a) a first power plant that produces secondary steam 5 from a first temperature; (b) a second power plant that has a higher operating temperature than that first temperature; and (c) superheat the steam from the first temperature to the highest temperature in the second power plant. 10 2. Hybrid power plant according to claim 1, characterized by the fact that the first power plant is selected from the list consisting of nuclear power plants and biomass powered power 3. Hybrid power plant according to claim 2, 15 characterized by the fact that the fossil fuel power plant is selected from the list consisting of power plants powered by coal, oil, oil, natural gas, propane and hydrogen.