Provided is a waste heat recovery power generation system, including: a compressor configured to compress a working fluid; a heat exchanger configured to recover waste heat from waste heat gas supplied from a waste heat source, the recovered waste heat heating the working fluid; a turbine configured to be driven by the working fluid heated by the recovered waste heat; and a recuperator configured to exchange heat between an output fluid of the turbine and an output fluid of the compressor to cool the output fluid of the turbine in which the output fluid of the compressor is branched into a first output fluid and a second output fluid of the compressor.

A supercritical carbon dioxide power generation Brayton cycle system and method that employs an alternate heat recuperation method and apparatus that utilizes switched banks of bead filled tanks to accumulate and recover the thermal energy of the two streams of working fluid in such a way that the variable thermal properties of the supercritical carbon dioxide can be accommodated without significant loss of thermal efficiency.

A unique method and ternary cycle process that captures heat from low temperature sources currently considered not commercially usable to produce electricity and desalinate water. In one cycle a novel flash tower operating at vacuum pressure causes a fraction of low temperature water to flash into steam. The steam passes to an indirect heat exchanger with a circulating refrigerating agent such as CO.sub.2, which condenses the steam on its outside surfaces to produce desalinated water product. The steam heat of condensation vaporizes the refrigerating agent, which is part of a binary refrigerate cycle that uniquely conditions it for turbine expansion to produce electricity in a connected electric generator.

Aspects of the invention provided herein include heat engine systems, methods for generating electricity, and methods for starting a turbo pump. In some configurations, the heat engine system contains a start pump and a turbo pump disposed in series along a working fluid circuit and configured to circulate a working fluid within the working fluid circuit. The start pump may have a pump portion coupled to a motor-driven portion and the turbo pump may have a pump portion coupled to a drive turbine. In one configuration, the pump portion of the start pump is fluidly coupled to the working fluid circuit downstream of and in series with the pump portion of the turbo pump. In another configuration, the pump portion of the start pump is fluidly coupled to the working fluid circuit upstream of and in series with the pump portion of the turbo pump.

Aspects of the invention provided herein include heat engine systems, methods for generating electricity, and methods for starting a turbo pump. In some configurations, the heat engine system contains a start pump and a turbo pump disposed in series along a working fluid circuit and configured to circulate a working fluid within the working fluid circuit. The start pump may have a pump portion coupled to a motor-driven portion and the turbo pump may have a pump portion coupled to a drive turbine. In one configuration, the pump portion of the start pump is fluidly coupled to the working fluid circuit downstream of and in series with the pump portion of the turbo pump. In another configuration, the pump portion of the start pump is fluidly coupled to the working fluid circuit upstream of and in series with the pump portion of the turbo pump.

The present invention provides a direct-fired supercritical carbon dioxide power generation system and a power generation method thereof, the system comprising: a combustor for burning hydrocarbon fuel and oxygen; a turbine driven by combustion gas discharged from the combustor; a heat exchanger for cooling combustion gas discharged after driving the turbine, by heat exchange with combustion gas recycled and supplied to the combustor; and an air separation unit for separating air to produce oxygen, wherein a portion of the combustion gas discharged after driving the turbine is branched before being introduced to the heat exchanger and is supplied to the air separation unit.

A 660MW supercritical unit bypass control method after a load rejection is provided. Steam channels after the load rejection are switched without an interference, and ache steam pressure is controllable. The 660MW supercritical unit bypass control method includes Pipeline 1, Pipeline 2, Pipeline 3, and Pipeline 4; a bottom of Pipeline 3, a bottom of the Pipeline 2, and a head of the Pipeline 4 are connected by a temperature and pressure reducer; a bottom of the Pipeline 1 is connected to a head of Pipeline 2; a branch pipe is arranged between the Pipeline 1 and the Pipeline 2, and a steam turbine is arranged in the branch pipe. A high-pressure bypass control system automatically adapts to the load rejection or FCB under any loading situation, avoids drastic changes of unit parameters from loading fluctuations, meets requirements of the load rejection and the FCB.

A combined cycle power plant includes a gas turbine, a steam turbine and a heat recovery steam generator. The heat recovery steam generator is arranged to receive exhaust gas from the gas turbine for reheating condensate from the steam turbine and generating steam for the steam turbine. And the heat recovery steam generator includes at least one drum evaporator configured to receive a first part of the condensate; a pump configured to receive a second part of the condensate and increase the second part of the condensate to an elevated pressure; and a high-pressure assembly configured to receive the condensate from the pump and operate the condensate from the pump at a subcritical up to a supercritical pressure range.

A combined cycle power plant includes a gas turbine, a steam turbine and a heat recovery steam generator. The heat recovery steam generator is arranged to receive exhaust gas from the gas turbine for reheating condensate from the steam turbine and generating steam for the steam turbine. And the heat recovery steam generator includes at least one drum evaporator configured to receive a first part of the condensate; a pump configured to receive a second part of the condensate and increase the second part of the condensate to an elevated pressure; and a high-pressure assembly configured to receive the condensate from the pump and operate the condensate from the pump at a subcritical up to a supercritical pressure range.

A coal-fired power generation system and a supercritical CO.sub.2 cycle system thereof are provided. The supercritical CO.sub.2 cycle system includes a compressor unit and a turbine unit. The turbine unit includes a preceding stage heater, a preceding stage turbine, a last stage heater and a last stage turbine successively connected in series. An exhaust port of at least one of compressors in the compressor unit is in communication with the turbine unit through a split flow pipe, and a communication position between the split flow pipe and the turbine unit is located downstream of a suction port of the preceding stage turbine. An auxiliary regenerator and an auxiliary heater are provided at the split flow pipe, and the auxiliary regenerator is located upstream of the auxiliary heater.