Showing papers on "Thermal power station published in 1973"

Combined steam turbine and gas turbine power plant control system

Abstract: A combined cycle power plant has a number of gas turbines each feeding exhaust gas to an associated heat recovery steam generator to generate steam which is supplied to a common header. Provision can also be made for supplementary firing of the heat recovery steam generator to produce additional steam flow. The combined cycle plant also has a steam turbine with a special control system to control steam pressure in the header and to supply the balance of the plant load. An overall combined plant control system assigns load to the individual gas turbine control systems, while the steam turbine control system controls steam pressure in the common header. The steam pressure level setpoint is ramped between selected operating pressure levels when adding or removing load, in accordance with the steam turbine valve positions, in order to achieve optimum operation of the steam turbine. A steam bypass valve control system is used to control pressure in the header during startup, and a supplementary firing control for the heat recovery steam generators may be included to achieve peak loads.

System and method for starting, synchronizing and operating a steam turbine with digital computer control

Abstract: Steam flow and pressure conditions needed in a turbine to satisfy the speed and load demand of an electric power generating system are controlled by a programmed digital computer system during start-up, synchronization and load operation Manual backup control is provided for the computer control Throttle valve tests are provided under digital control and transfers are made to manual backup control if predetermined task errors occur

Reactor megawatt demand setter

Abstract: The electrical power output of a nuclear powered generating station, as requested by an operator or by an automatic dispatch system for the grid with which the station is associated, is controlled in a manner which insures that the nuclear steam supply system limits are not violated. The invention permits the nuclear powered generating unit to operate at maximum permissible power for the existing nuclear steam supply system conditions by exercising control over the unit turbine in such a manner that the rate of load change will be controlled as a function of the proximity of the actual load to the desired load and the rate of load increase will be algebraically limited by the proximity of the nuclear steam supply system conditions to the steam supply system operating limits. Additionally the turbine load will automatically be reduced when necessary at a rate which equals or exceeds a value which is commensurate with the magnitude of any violation of the steam supply system operating limits.

Combined steam and gas turbine power plant having gasified coal fuel supply

Abstract: A combined cycle power generating plant is provided in which both the steam turbine and the gas turbine burn gasified coal as a fuel. The steam turbine meets base and intermediate power demands and during these periods the gas produced in the gasifier in excess of what is burned in the steam generator is compressed and stored in a gas holder. When peaking power is needed the gas turbine is fired using the gas stored during the periods of low demand.

Energy forests and fuel plantations

Abstract: A discussion of the use of specially grown forests to fuel a steam electric power plant covers the advantages of such a system over the use of fossil fuels, including the absence of sulfur dioxide and other types of pollution; advantages over nuclear fuels, including the absence of thermal pollution, the safety, and more advanced technology; advantages over other means for harnessing solar energy, including lower capital cost requirements; land requirements for energy plantations, which are approximately equivalent to the land bases that support kraft pulp mills in the southern US; economics; yield of fuel; the effect of moisture; estimated insulation rate (the rate of delivery of direct solar energy); fuel production costs and prices, including the fuel cost of pulp wood, corn, and perennials; and price competitiveness with fossil fuels Tables, graphs, and 23 references

Method of operating a combined gasification-steam generating plant

Abstract: A steam generating plant is provided which includes an entrainment, slagging, air blown atmospheric pressure coal gasifier, a heat recovery train, atmospheric pressure desulfurization and a steam generator designed to burn the low Btu fuel gas produced in the gasifier. Heat recovered from the gas produced in the gasifier is used to raise the temperature of a portion of the steam generator feedwater, generate steam for use in the gasifier, and to reheat the fuel gas following desulfurization. Heat recovered from boiler flue gas is utilized in drying and preheating the reactants to the gasifier.

Consolidated nuclear steam generator

Abstract: This invention relates to an improved system of providing power having a unique generating means of the nuclear reactor variety adapted with a plurality of steam generators in the form of replaceable modular units of the expendable type for the attainment of the optimum in effective and efficient vaporization of fluid during the process of generating power.

Power generating plant with nuclear reactor/heat storage system combination

Abstract: Excess heat output of a nuclear reactor is stored at high temperature. This stored heat is then used to generate steam to operate a turbine-generator during high power demand periods. An arrangement is described herein in which a fluoride salt fusion heat storage system is used from which heat is retrieved by circulating liquid lead therethrough. The liquid lead heat retrieval circuit includes a steam boiler in which steam for operation of a turbine-generator is generated using heat extracted from the heated liquid lead.

Steam power stations

Abstract: The steam power station includes an accumulator for storing heat drawn from the operating steam cycle during slack operating periods when the power network demand on the station is low, and restoring the heat to the steam cycle at peak or high-demand periods, to adapt the station to a variable demand network. The transfer of heat between the operating installation of the station, which includes a steam turbine, and the accumulator, is made by way of a heat-transfer fluid which is in heat-transfer relation with the steam of which at least a part has done mechanical work in the turbine. The heat-transfer fluid is reversibly circulated in heat-transfer relation with the steam in such a way that the heat-transfer from the steam to said fluid occurs at substantially the same temperature as the transfer from said fluid to the steam. The installation can also heat feed water returning to the steam generator by tapping off live steam for said heating at the outlet from the generator. The installation can have apparatus for separating into liquid and dry steam partially expanded steam issuing from the turbine, the liquid from that apparatus being vaporised by heat from a heat accumulator supplied with heat from the heat source of the installation; all the liquid is vaporised during high-demand periods while in slack periods all the liquid is restored to the feed water circuit to the steam generator.

Gas turbine power plant control apparatus including a temperature reset starting control system and an ignition pressure control system

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Method and apparatus for drying moisture-containing solids particularly domestic refuse and sludge cakes

Abstract: Method and apparatus are described for the production of solid fuel and steam by drying moisture-containing solids, such as refuse and sludge cakes, in a multi-stage heating zone by using the moisture-containing solids as the feed-water in a direct contact countercurrent flow pressurized boiler. After vaporizing the bulk of the moisture in the heating zone of the boiler, the solid residue is further dried in a multi-stage flashing zone. From the upper end of the heating zone is removed a nearly saturated steam including the water vapor evaporated from the moisture-contained solids by the heat of cooling of the introduced superheated steam. A portion of the removed steam equal to the vaporized moisture is heated and then directed to a turbine, generating all the power required to operate the system. The bulk of the removed steam equal to the introduced superheated steam is compressed, reheated and recycled through the heating zone. The dried solid is removed at the lower end of the flashing zone and is incinerated, and the recovered heat is utilized to supply the heat required for said drying, and to produce saturated steam for heating purposes, or superheated steam for power generation. In the latter case the heat of condensation of the turbine exhaust steam is utilized advantageously as a heat source in a distillation plant for fresh water production.

Electric power plant system and method for operating a steam turbine especially of the nuclear type with electronic reheat control of a cycle steam reheater

Abstract: An electronic system is provided for operating a nuclear electric power plant with electronic steam reheating control applied to the nuclear turbine system in response to low pressure turbine temperatures, and the control is adapted to operate in a plurality of different automatic control modes to control reheating steam flow and other steam conditions, each of such modes of control permitting turbine temperature variations within predetermined constraints and according to predetermined functions of time.

Wide range system for transferring steam generator and turbine operation between computers in a multiple turbine computer control system

Abstract: An electric power plant including a steam generator and a steam turbine is operated by a control system including two redundant digital computers. Switching circuitry is provided for coupling one of the computers through interface equipment to the steam generator and the turbine and a generator according to programmed computer control. A data link is established between the computers to transfer manual/automatic status and other needed data from the control computer to the standby computer. A system is provided for detecting when certain hardware and software malfunctions have occurred and for responsively transferring control to the standby computer. The standby computer is tracked to the control computer so that control computer transfer can be made reliably without disturbing the electric power generation process. The turbine control includes a speed control loop which is implemented with computer operations. Startup control is also implemented in startup control loops for the steam generator by means of computer operations. Computer transfers are executed smoothly in the startup control mode at substantially any stage of the startup process.

Method and means for heating buildings in a district heating system with waste heat from a thermal power plant

Abstract: The waste heat from a thermal power plant is transported through a municipal heating network to a plurality of buildings to be heated. The quantity of heat thus supplied to the buildings is higher than that required for the heating of the buildings. The excess heat is released from the buildings to the atmosphere in the form of hot air.

Systems and method for organizing computer programs for operating a steam turbine with digital computer control

Abstract: Steam flow and pressure conditions needed in a turbine to satisfy the speed and load demand of an electric power generating system are controlled by a programmed digital computer system during start-up, synchronization and operation. Manual backup control is provided for the computer control. An operator interface is provided with the computer through a panel and various communication devices.

Volume reduction of spent radioactive ion exchange resin

Abstract: A process for reducing the volume of spent radioactive ion exchange resins which have been used for conditioning water circulated through a nuclear reactor. The spent resins are discharged from the reactor system as radioactive wastes to a spent resin storage tank in the form of a slurry. The slurry is first vacuum dewatered to remove the free water and then the intrinsic water in the wet resin beads is removed by drying in a vacuum fluidized bed chamber utilizing superheated steam which also acts to fluidize the bed. Further drying is accomplished by spraying the partially dried resin and superheated steam through a steam injected two-fluid nozzle for further extraction of intrinsic water from the resins. The steam is discharged to a condenser and the dried resins to an evacuated disposal drum. Approximate 4:1 volume reductions from the resin-water slurry to the dried resin is obtainable by practicing the process.

Thermal power plant

Abstract: There is provided a thermal power plant in which an air compressor is charging a rock chamber with compressed air. The rock chamber is communicating via a conduit with a water reservoir being located at a higher level than the rock chamber. A water pump being installed in the conduit is improving the counter action of the water column on the air pressure, and thus the air storage capacity of the rock chamber. The compressed air is fed to a gas turbine when additional power is needed.

Gas turbine power plant control apparatus including automatic load pickup

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Gas turbine power plant control apparatus including a speed/load hold and lock system

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

Wide load range system for transferring turbine or plant operation between computers in a multiple computer turbine and power plant control system

Abstract: An electric power plant including a steam generator and a steam turbine is operated by a control system including two redundant digital computers. Switching circuitry is provided for coupling one of the computers through interface equipment to the steam generator and the turbine and a generator according to programmed computer control. A data link is established between the computers to transfer manual/automatic status and other needed data from the control computer to the standby computer. A system is provided for detecting when certain hardware and software malfunctions have occurred and for responsively transferring control to the standby computer. The standby computer is tracked to the control computer so that control computer transfer can be made reliably without disturbing the electric power generation process. The turbine control includes a load control loop which is implemented with computer operations. Load control is also implemented in load control loops for the steam generator by means of computer operations. Computer transfers are executed smoothly in the load control mode at substantially any load level of operation.

Trace element mass balance around a coal-fired steam plant

Abstract: In a collaborative effort between Oak Ridge National Laboratory and the Tennessee Valley Authority, mass balance measurements for some 41 elements have been made around the Thomas A. Allen Steam Plant in Memphis, Tennessee. For one of the three independent cyclone boilers at the plant, the concentration and flow rates of each element were determined for: (1) the coal, (2) the slag tank effluent, (3) the fly ash in the precipitator inlet and outlet (collected isokinetically at a representative series of duct locations determined by the gas flow profiles), and (4) fly ash in the stack gases (collected isokinetically at the 268-ft level). Measurements by neutron activation analysis, spark source mass spectroscopy (with isotope dilution for some elements), and atomic adsorption spectroscopy yielded an approximate balance (closure to within 30 percent or less) for many elements. Exceptions were those elements forming volatile compounds such as Hg. For most elements in the fly ash the newly installed electrostatic precipitators were extremely efficient. An exception seems to be Se.

Thermal power plants

Abstract: A thermal power plant such as a nuclear power plant where a primary circuit is provided for generating primary power while an accumulator circuit communicates with the primary circuit for generating additional power to be utilized for peak loads The accumulator circuit includes displacement accumulators communicating with steam-generating units for providing the energy to be utilized for the additional peak power Fluid is circulated between the displacement accumulators and steam generator units by way of a circulating conduit system and a fluid-circulating structure communicating therewith This fluid-circulating structure is driven from a drive accumulator, so that it is not necessary to use electricity in order to circulate the fluid of the accumulator circuit

Reactor-turbine control for low steam pressure operation in a pressurized water reactor

Abstract: A control system for a pressurized water reactor power plant. The control system comprises temperature sensing means having flow interruption means connected thereto. The temperature sensing means monitors the temperature levels within the reactor element and sends a predetermined signal to the flow interruption means upon a predetermined change in reactor temperature. The flow interruption means is disposed within an associated steam turbine loop including a steam generator element which transforms secondary water into steam to act as motive fluid within the turbine loop. The flow interruption means initiate one or more flow interruption activities which either produce an increased temperature differential between the secondary water and the steam produced therefrom or increase the rate of flow of steam within the associated steam turbine loop. Utilization of the control system permits extensive operation of the reactor element past the end of the normal fuel cycle life. In addition, the control system provides improved reactor load follow capability.

Fluid distribution network and steam generators and method for nuclear power plant training simulator

Abstract: A training simulator for the real-time dynamic operation of a nuclear power plant utilizes apparatus that includes control consoles having manual and automatic devices corresponding to simulated plant components and indicating devices for monitoring physical values in the simulated plant. A digital computer configuration is connected to the control consoles to calculate the dynamic real-time simulated operation of the plant in accordance with the simulated plant components to provide output data including data for operating the control console indicating devices. In the method and system for simulating a fluid distribution network of the power plant, such as that which includes, for example, a main steam system which distributes steam from steam generators to high pressure turbine steam reheaters, steam dump valves, and feedwater heaters, the simultaneous solution of linearized non-linear algebraic equations is used to calculate all the flows throughout the simulated system. A plurality of parallel connected steam generators that supply steam to the system are simulated individually, and include the simulation of shrink-swell characteristics.

Off-line integration of bridge and boiler controls

Abstract: An apparatus and method for controlling a steam generator operating under rapidly varying load conditions. The method measures steam flow and pressure and combines the measurements with a signal that is proportional to the rate of change of steam flow and utilizes the resulting signal to control the fuel and air flow to the steam generator.

Compact V-form pressurised auxiliary condensers - dissipating excess steam and decay heat in PWR power plant

Abstract: Auxiliary steam condenser circuit is for nuclear power generating plant in which the condenser is integrated with the prim. coolant circuit and an after coller and operates at a min. pressure of 5 bars. Operating pressures at half or nominal steam working pressure are also possible with natural re-circulation of the condensate obtg. at the higher pressures. A V-form tubular configuration is adapted for the auxiliary condensers which are sited above each steam raising unit. Secondary coolant, boronated and de-ionised water services are sited outside the reactor building with the main steam relief and isolating valves inside. System is used for dissipation of excess steam and reactor decay heat in pressurised water reactor power plant following loss of load or emergency shut-down reactor conditions. Using this system the plant if of smaller dimensions and less expensive.

The Inverted Brayton Cycle for Waste-Heat Utilization

Abstract: The inverted Brayton cycle, which can be simply defined as one in which hot gas is first expanded through a turbine to low pressure, is then cooled at constant pressure, and lastly, is recompressed to the initial pressure, has been shown to give attractive incremental gains in thermal efficiency, and large returns on investment, when added to a conventional shaft-power gas turbine exhausting into a waste-heat boiler. When the inverted Brayton cycle is applied by itself as a method of obtaining shaft power from the hot waste gas stream, there appears to be range of temperature and pressure ratios at which the cycle is competitive with other methods of waste-heat utilization.Copyright © 1973 by ASME

Shell and tube heat exchanger

Abstract: An improved shell and tube heat exchanger is described wherein power steam for driving a turbine is reheated between successive stages of the turbine. The power steam passing through the shell is heated by heating steam passing through heating tubes, the exchanger being of the type having steam distribution elements including a main inlet header adapted to distribute heating steam to the heating tubes, a main outlet header located to collect the heating steam from the heating tubes, a plurality of pairs of inlet and outlet subheaders, feeder tubes for coupling each of the inlet and outlet subheaders to the main inlet header and main outlet header respectively, and heating tubes coupling the inlet and outlet subheaders of each pair. The heat exchanger is characterized by an improved arrangement of the distribution elements to provide improved allocation of the heating steam to uniformly heat power steam of varying moisture distribution and hence different local heat transfer requirements, without developing degenerative heat transfer conditions. In the improved arrangement of distribution elements, each pair of inlet and outlet subheaders has a uniform number of heating tubes in relation to the quantity of heating steam applied by the feeding tubes coupled to that pair, to provide a uniform quantity of heating steam for each heating tube, whereby power steam of varying moisture distribution is heated with steam pressure loads remaining substantially independent of heat transfer variations in the individual heating tubes.