Systems and methods for improving the efficiency of a power plant exploit the temperature differential of the cooling water that may exist seasonally in some geographic locations. Specifically, new systems and ways of retrofitting existing systems to utilize the additional temperature differential of a power plant's coolant during colder months are provided in order to increase the efficiency of the plant. A second working fluid loop converts a portion of the condenser of the first working fluid loop into the boiler for the second working fluid loop in which the first and second working fluids in these respective loops are different. Thus, the energy output of the plant may be increased by the addition of a selectively operated secondary loop without an increase in fuel consumption.

Systems and methods for improving the efficiency of a power plant exploit the temperature differential of the cooling water that may exist seasonally in some geographic locations. Specifically, new systems and ways of retrofitting existing systems to utilize the additional temperature differential of a power plant's coolant during colder months are provided in order to increase the efficiency of the plant. A second working fluid loop converts a portion of the condenser of the first working fluid loop into the boiler for the second working fluid loop in which the first and second working fluids in these respective loops are different. Thus, the energy output of the plant may be increased by the addition of a selectively operated secondary loop without an increase in fuel consumption.

The invention relates to a method for controlling ORC stacks with a total number n.sub.tot of individually operable ORC modules, said method comprising the following steps: determining the running time remaining until the next servicing time for each operable ORC module respectively; determining a target number n.sub.soll of ORC modules to be operated; comparing said target number n.sub.soll to an actual number n.sub.ist of currently operated ORC modules; when n.sub.soll>n.sub.ist, connecting a number n.sub.solln.sub.ist of ORC modules that corresponds to the difference between the target number and the actual number, where the ORC modules with the longest remaining running times of the ORC modules currently not being operated are connected; and/or when n.sub.soll<n.sub.ist, disconnecting a number n.sub.istn.sub.soll of ORC modules that corresponds to the difference between the actual number and the target number, where the ORC modules with the shortest remaining running times of the ORC modules currently being operated are disconnected; and/or when n.sub.soll=n.sub.ist, connecting the ORC module with the longest remaining running time t.sub.1 of the ORC modules not currently being operated, and disconnecting the ORC module with the shortest remaining running time t.sub.2 of the ORC modules currently being operated, if t.sub.1>t.sub.2.

The invention relates to a method for controlling ORC stacks with a total number n.sub.tot of individually operable ORC modules, said method comprising the following steps: determining the running time remaining until the next servicing time for each operable ORC module respectively; determining a target number n.sub.soll of ORC modules to be operated; comparing said target number n.sub.soll to an actual number n.sub.ist of currently operated ORC modules; when n.sub.soll>n.sub.ist, connecting a number n.sub.solln.sub.ist of ORC modules that corresponds to the difference between the target number and the actual number, where the ORC modules with the longest remaining running times of the ORC modules currently not being operated are connected; and/or when n.sub.soll<n.sub.ist, disconnecting a number n.sub.istn.sub.soll of ORC modules that corresponds to the difference between the actual number and the target number, where the ORC modules with the shortest remaining running times of the ORC modules currently being operated are disconnected; and/or when n.sub.soll=n.sub.ist, connecting the ORC module with the longest remaining running time t.sub.1 of the ORC modules not currently being operated, and disconnecting the ORC module with the shortest remaining running time t.sub.2 of the ORC modules currently being operated, if t.sub.1>t.sub.2.

A single shaft combined cycle power plant includes a shaft on which is sequentially located, a gas turbine, a medium pressure steam turbine, a low pressure steam turbine, a generator, and a high pressure steam turbine, wherein the gas turbine and the high pressure steam turbine are at opposite ends of the shaft.

A single shaft combined cycle power plant includes a shaft on which is sequentially located, a gas turbine, a medium pressure steam turbine, a low pressure steam turbine, a generator, and a high pressure steam turbine, wherein the gas turbine and the high pressure steam turbine are at opposite ends of the shaft.

A novel concept for a high energy and material efficient nitric acid production process and system is provided, wherein the nitric acid production process and system, particularly integrated with an ammonia production process and system, is configured to recover a high amount of energy out of the ammonia that it is consuming, particularly in the form of electricity, while maintaining a high nitric acid recovery in the conversion of ammonia to nitric acid. The energy recovery and electricity generation process comprises pressurizing a liquid gas, such as air, oxygen and/or N.sub.2, subsequently evaporating and heating the pressurized liquid gas, particularly using low grade waste heat generated in the production of nitric acid and/or ammonia, and subsequently expanding the evaporated pressurized liquid gas over a turbine. In particular, the generated electricity is at least partially used to power an electrolyzer to generate the hydrogen needed for the production of ammonia. The novel concepts set out in the present application are particularly useful in the production of nitric acid based on renewable energy sources.

A system and method are provided for storing and recovering electricity generated from conventional/renewable energy sources. A thermal energy storage vessel contains thermal storage fluid (TSF) comprising a eutectic ternary nitrate molten salt, induction heating elements, turbine pumps, a heat exchanger, and various data acquisition sensors like thermocouples and thermistors. The immersion heating elements receive the electricity generated from conventional and/or renewable energy source to heat the eutectic ternary nitrate molten salt to the desired temperature. Coiled tubing is deployed within the thermal containment vessel to be distribution systems for the power cycle working gas and heat exchange for the power cycle working gas. The power cycle working gas is delivered under pressure to a steam turbine. The turbine converts the energy into mechanical shaft work to drive an electricity generator to produce electricity. The steam exhaust is gathered by a compressor and returned to the thermal energy storage vessel.

A system and method are provided for storing and recovering electricity generated from conventional/renewable energy sources. A thermal energy storage vessel contains thermal storage fluid (TSF) comprising a eutectic ternary nitrate molten salt, induction heating elements, turbine pumps, a heat exchanger, and various data acquisition sensors like thermocouples and thermistors. The immersion heating elements receive the electricity generated from conventional and/or renewable energy source to heat the eutectic ternary nitrate molten salt to the desired temperature. Coiled tubing is deployed within the thermal containment vessel to be distribution systems for the power cycle working gas and heat exchange for the power cycle working gas. The power cycle working gas is delivered under pressure to a steam turbine. The turbine converts the energy into mechanical shaft work to drive an electricity generator to produce electricity. The steam exhaust is gathered by a compressor and returned to the thermal energy storage vessel.

A heat exchanger is for use in an energy recovery system to be mounted on a vessel including an engine, a supercharger and an economizer, the heat exchanger including: a first heat section for heating a working medium by supercharged air from the supercharger; a second heat section for heating the supercharged air by steam generated by the economizer before the supercharged air flows into the first heat section; and a third heat section for heating the working medium having been heated in the first section by the supercharged air which is to be heated in the second section.