Showing papers on "Thermal power station published in 1978"

Removal of acid gases from hot gas mixtures

Abstract: A process for removing acid gases such as CO 2 and H 2 S from gas streams using an aqueous alkaline scrubbing solution which is circulated between an absorption and regeneration stage wherein the stripping steam for regeneration is derived at least partly from the hot feed gas to be purified. The thermal efficiency of the process is substantially improved by first heat-exchanging the hot feed gas with the scrubbing solution to raise stripping steam and then heat-exchanging the hot feed gas with water (which is preferably condensate water produced in the scrubbing process) in a second heat exchanger operating under reduced pressure, thus recovering additional low-level heat from the feed gas and producing low-pressure steam which is compressed and then utilized as additional stripping steam. In a preferred embodiment, additional low-pressure steam is generated by also flashing off low-pressure steam from the regenerated scrubbing solution and compressing this steam together with the steam produced in the second heat exchanger for use as stripping steam.

Core design and operating data for Cycles 1 and 2 of Peach Bottom 2

Abstract: The design and operating data needed to define the fuel characteristics, vessel internal components, nuclear steam supply system components, and reactor operation characteristics for Cycles 1 and 2 of the Peach Bottom 2 reactor are presented. The purpose is to provide reference quality data for use in the qualification of reactor core analysis methods and to provide the basis for the assessment of the irradiation environment during Cycles 1 and 2. The design data includes fuel assembly description, core component arrangements, control rod descriptions, core loading patterns, reactor internals description, and major piping arrangements. Hydraulic characteristics of the assemblies and the inlet orifices are also provided. Operating data is compiled for 24 steady-state points during Cycle 1 and 13 during Cycle 2. Each state point includes core average exposure, thermal power, pressure, flux, inlet subcooling, control configuration and axial in-core detector readings.

Method and apparatus for vaporizing liquid natural gases

Abstract: Liquid natural gases are vaporized by directing them into heat exchange relationship with waste heat produced from a thermal power engine. In a closed turbine cycle system, vapor which is discharged from the turbine is passed through one or more heat exchangers and the natural gas is moved through the heat exchanger in heat exchange relationship with the vapor to effectively cool the vapor as well as to evaporate the natural gases which are supplied in a liquid form, for example.

Multiple turbine electric power plant having a coordinated control system with improved flexibility

Abstract: A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. Afterburners further heat the exhaust gases from each gas turbine prior to their passage to respective heat recovery sections of the steam generator. The power plant control system provides coordinated plant control or coordinated control of selected turbines and afterburners in both startup and load operations, with load distribution optimized according to the turbines under coordinated control. Transfer between coordinated control and alternate modes of plant control may be done by operator selection or automatically upon sensed conditions.

Reheat gas turbine combined with steam turbine

Abstract: A process and apparatus for generating useful power comprises the use of a combined reheat gas turbine and steam turbine cycle. The combined cycle optionally includes the superheating of steam and the reheating of steam in the reheat combustor of the reheat gas turbine. The use of second generation high-ratio, high-firing temperature gas generators in the combined cycle of the present invention yields increased efficiency and output heretofore unexpected from reheat gas and combined cycles.

Process for operating a combined gas turbine/steam turbine installation with an integrated partial fuel-combustion process

Abstract: A process for operating a combined gas turbine/steam turbine power plant having an integrated partial fuel-combustion process is disclosed wherein a portion of a supply of compressed air is fed to a combustion reactor in which a fuel is gasified. The gasified fuel is combusted to drive a gas turbine with the discharge from the gas turbine heating a waste heat steam generator. Steam is generated in a boiler heated by the gasified fuel and drives a steam turbine. The steam is saturated in the boiler and is dried and heated in a heat exchanger arranged downstream of the boiler and upstream of the waste heat steam generator. The heat exchanger is heated by the portion of the compressed air with the air further compressed immediately downstream of the heat exchanger.

Geothermal preheating in fossil-fired steam power plants

Abstract: A thermodynamic analysis of a hybrid fossil geothermal power plant in which the low-grade geothermal energy is used for preheating the feedwater in a fossil-fired steam power plant is presented. By restricting the geofluid to sensible heat addition, the entropy production in this process can be reduced. This results in an overall improvement in the utilization of the two energy sources. The performance of the hybrid system is studied in terms of suitably defined figures of merit. These include criteria for the choice of the appropriate hybrid utilization strategy, given the finite nature of geothermal and fossil resources. The question of optimum bleed conditions in a cycle comprising both geothermal and regenerative feedwater heating is discussed.

Gas turbine engine power plant using solar energy as a heat source

Abstract: The working medium of a gas turbine engine power plant is heated indirectly by energy derived by solar radiation, the power plant comprising radiant energy collecting means, radiant energy receiving means, radiant energy heat transfer means, a relatively large capacity pressurized heat store and a gas turbine engine in which the compressed air is heated by heat energy in the heat store.

Central heating systems furnace having a self-contained electric steam heating unit

Abstract: A central heating system furnace includes a self-contained closed-system steam heating unit mounted in a housing having a cold air inlet and a hot air outlet. The unit includes a plurality of side-by-side radiators arranged above a boiler unit having an electric heating element immersed in a quantity of vaporizable liquid. Each radiator comprises a plurality of tubular, finned, heat exchange risers arranged in a row and extending between upper and lower manifolds. In order to distribute steam evenly among each of the radiators and to prevent unvaporized liquid from entering the risers thereof, a horizontal steam tube communicating with the boiler unit is positioned between the boiler unit and radiators and supplies steam to each radiator through a separate steam distributing member in the lower manifold thereof, each steam distributing member including a plurality of steam discharge tubes extending upwardly into the lower portion of different risers of the radiator to distribute steam evenly. A condensate return tube communicates each lower manifold with the boiler unit. A blower circulates air to be heated through the housing over the steam heating unit from the air inlet to the air outlet.

Characterization and reuse of ash pond effluents in coal-fired power plants

Abstract: TVA has been characterizing wastewaters from coal-fired power plants since 1968. Information on ash pond effluents and schemes for reusing ash sluice water and other waste streams within power plants is provided. The main factors that affect the characteristics of TVA's ash pond discharges are the coal source, the firing method, the quantity and quality of water used for sluicing, efficiency of flyash collection methods, and performance of settling ponds. Four of 12 schemes for reuse of ash pond effluents are detailed. (7 diagrams, 6 graphs, 16 references, 4 tables)

Apparatus for recovering heat from exhaust gases of marine prime movers

Abstract: An apparatus for recovering heat from the exhaust gases of marine prime movers of the kind including an exhaust gas economizer for effecting heat exchange between the exhaust gas discharged from the prime mover and feed water supplied under pressure from a feed water tank. The apparatus has a pressure regulator device for regulating the pressure of the feed water to provide sources of relatively high and low pressure feed water; a high pressure steam generator section in the exhaust gas economizer to receive high pressure feed water to generate high pressure steam for use in driving a steam turbine; a low pressure steam generator section in the economizer to receive low pressure feed water to generate general purpose steam for use for purposes other than driving the steam turbine; a low pressure steam separating device at the outlet of the low pressure steam generator section for separating saturated water from the general purpose steam; and a primary feed water preheater in a line connecting the feed water tank to the low pressure steam generator section for mixing the saturated water separated by the low pressure steam separator device and the feed water supplied from the feed water tank to the exhaust gas economizer and thereby preheating the feed water.

Fossil superheating in geothermal steam power plants

Abstract: Results of thermodynamic studies of geothermal steam power systems incorporating fossil-fired superheaters are reported. One- and two-stage systems are covered. Realistic assumptions have been included to account for losses that may be incurred in actual plants. The systems are evaluated on the basis of a number of appropriate figures of merit. It is found that fossil superheat hybrid geothermal power plants offer a thermodynamic advantage over individual fossil and geothermal plants for a wide range of operating conditions, and deserve consideration whenever fossil and geothermal energy resources are found in reasonable proximity.

Low boiling point medium power plant

Abstract: A low boiling point medium power plant in which heated waste gas, such as furnace gas, geothermic steam, etc., is used as a heat source for heating an intermediate thermal medium by means of an indirect heat exchanger, and the intermediate thermal medium is used as a heat source for heating a turbine driving low boiling point medium by means of a direct heat exchanger. The indirect heat exchanger and the direct heat exchanger are rendered into a unitary structure and contained in a sealed housing together with a turbine, a generator and a condenser, whereby a compact overall size can be obtained in a low boiling point medium power plant.

Apparatus for providing radiative heat rejection from a working fluid used in a Rankine cycle type system

Abstract: Radiative heat rejection for the condensate of a steam system in which panels painted with titanium dioxide are put out in the desert and water as a heat exchange fluid is flowed on the underside of the panels. They will radiate into the night sky and produce significant cooling and provide for rejection of condenser heat from Rankine cycle water and steam turbines as well as reflect the sun. In addition to titanium dioxide panels one can use reversible plastic mattresses floating on a cool pond coated black on one side and silver on the other and with the black surface up at night, silver surface up in the daytime; they too will provide radiative heat rejection.

Fuel-efficient generation of ejecting steam

Abstract: A fuel-efficient method and apparatus for the generation, actually re-generation, of ejecting steam used in a steam ejection system to evacuate process vapor from an enclosed space. In the method, all of the ejecting steam is not generated continuously in a boiler, but a predetermined quantity of steam is reused by continuous mechanical recompression, without intervening condensation, in a returning cycle while alternating between a pressure low after ejection (i.e. expansion) and a pressure high after recompression, whereas the evacuated vapor is branched off from the ejecting steam cycle after ejection and condensed. Parts of the condensate are reconverted to additional steam by heat exchange with all or part of the superheat and friction heat contained in the recompressed ejecting steam and/or by heat exchange with the exhaust and cooling system of a heat engine serving as a prime mover for the compressor. This thermally generated additional steam either may be supplied to the outside as output steam or may be employed as additional ejecting steam. The average specific thermal input into the steam, consisting partly of recompressed and partly of thermally generated steam, amounts to roughly 50% of the analogous specific thermal input in prior art.

Recovery of thermal energy from a thermomechanical pulp plant

Abstract: A method of recovering the thermal energy contained in the pressurized steam utilized during the production of thermomechanical pulp The steam is applied to the primary side of a heat exchanger with water supplied to the secondary side in order to produce hot water The water is vaporized to produce clean steam The clean steam is then utilized to at least a first steam group of the drying sections of a paper manufacturing machine without increasing the pressure of the clean steam

System for minimizing valve throttling losses in a steam turbine power plant

Abstract: A system which integrates the controls of a steam turbine power plant for minimizing power plant energy losses substantially caused by steam flow valve throttling is disclosed. The steam turbine power plant includes boiler pressure controls for controlling the boiler throttle pressure of a steam producing boiler and turbine-generator controls for positioning a plurality of turbine steam admission values to regulate the steam flow conducted through a steam turbine which governs the electrical energy generated by an electrical generator at a desired power generation level. The turbine-generator controls predetermines a plurality of valve position states to establish a predetermined valve grouping sequential positioning pattern for the steam admission valves to regulate steam flow through the steam turbine across the range of power generation, each predetermined state substantially corresponding to a minimum of valve throttling losses. The steam admission valves may be positioned at a present valve position state, which is other than one of the predetermined states, as a result of a change in desired power generation level. The disclosed system responds to this condition by governing the boiler pressure controls to adjust the boiler throttle pressure at a desired rate and in a direction to cause steam admission valves to be repositioned according to the sequential positioning pattern to a selected one of the predetermined efficient valve position states. The repositioning of the steam admission valves is performed by maintaining the generated energy substantially at the new desired power generation level.

Gas-cooled high temperature nuclear reactors

Abstract: A gas-cooled, and preferably helium cooled, graphite-moderated high temperature nuclear reactor of the kind having a pressure vessel containing a reactor core with fuel elements, graphite components and a primary coolant gas circuit including a steam generator and coolant gas blowers, has the steam generator disposed outside the pressure vessel and the steam generator includes a heat exchanger at least a portion of which is located above the level of the reactor core. This situation of the heat exchanger ensures that when the reactor is shut down, either intentionally or owing to a fault, a natural convection flow takes place through the coolant gas circuit and this natural convection flow is in the same direction as it is when the blowers are functioning so that the flow conducts away the decay heat from the core to the steam generator in the same way as when the blowers are in operation.

Energy conversion method with water recovery

Abstract: A mechanical energy conversion method and system for the restoration of dissipated heat energy, contained in natural or artificial water bodies at or near ambient temperatures, to industrial process heat, mainly in the form of steam up to 200°-400° C. The sensible heat contained in a water body is concentrated as latent heat in low pressure water vapor which is thermo-compressed by steam ejection to an intermediate pressure level, wherefrom mechanical compression takes over, generating highly superheated output steam. The ejecting steam is not generated in a boiler, but is continuously regenerated by the compressor and routed back for repeated ejection. The compressor is driven by a heat engine whose reject heat is collected and upgraded as well. The output of heat energy is essentially equal to the sum of the heating value of the fuel consumed and the intake of latent heat and amounts thus to substantially more than the heating value of the fuel alone.

Ocean thermal energy conversion system and method for operation

Abstract: A power generation system and method of operation for generating electricity by utilizing temperature differences inherently present in the ocean between water near the surface and water from the ocean's depths. A pump provides relatively warm, surface ocean water to a flash evaporator where a portion of the water is flashed into steam. The steam is expanded through a subatmospheric pressure range turbine which exhausts into a condensing enclosure. The steam exhausting into the enclosure is condensed by relatively cold ocean water pumped thereinto. The turbine drives a generator and thus produces the electricity. The turbine speed and generator output are controlled by selectively introducing atmospheric air and relatively warm water into the exhausted motive steam flow. Such selective introduction into the exhausted steam flow of air and/or relatively warm water increases the absolute pressure at the turbine's exhaust end and thus reduces steam flow through the turbine. Adjusting regulating valves for the air and warm water flows in response to changes in turbine speed and/or generator load provides means for regulating the speed of the turbine and generating load.

Organic Rankine cycle

Abstract: Organic Rankine cycle systems are currently being developed for waste heat recovery systems from thermal power plants and industrial plants. DOE is supporting the development of three unique concepts of packaged Rankine cycle systems using different working fluids ranging from steam to Freon. The systems will recover the waste heat from the prime mover exhaust streams and convert it to additional useful shaft power at efficiency levels of 18 to 20%.

Efficient valve position controller for use in a steam turbine power plant

Abstract: An efficient valve position controller adapted for use in a steam turbine power plant for efficiently positioning a plurality of steam admission valves to substantially effect a desired power generation level is disclosed. The power plant includes a boiler for generating steam to the turbine at a boiler throttle pressure that is governed by a pressure set point; a valve control means which is governed by a reference signal corresponding to the desired power generation level to position the plurality of steam admission valves in a state according to a predetermined valve positioning pattern based on the value of the reference signal; and an electrical generator driven by the steam turbine to generate electrical energy. A plurality of values of the reference signal are predetermined as being related to efficient valve position states for regulating steam admission to the turbine. The controller adjusts the pressure set point at a desired rate and in a direction as determined by the difference between a selected one of the predetermined values and a present value of the reference signal. Accordingly, the reference signal is modulated as a function of the pressure set point adjustment until the reference signal is substantially equal to the selected value at which time the reference signal is governing the valves substantially at an efficient valve position state and further pressure set point adjustment is inhibited. In addition, when the reference signal becomes equal to a predetermined threshold value which is indicative of the steam admission valves being substantially wide open, the pressure set point is adjusted to a preset value.

Heat transfer lens steam turbine

Abstract: This invention relates to a steam turbine system which utilizes a unique heat-absorbing lens-shaped heating plate and boiler for the production of steam.

Steam Bottoming Plants for Combined Cycles

Abstract: For bottoming Rankine cycles, the advantages of steam have so far prevailed and with the exception of a few experimental installations, all commercial bottoming cycles have used H/sub 2/O. The advantages of steam include low cost, chemical stability and inertness, high specific heat, and high heat transfer rates. Disadvantages of steam include low molecular weight, high latent heat, and high critical pressure. It is shown that some of the disadvantages of steam for bottoming cycles can be overcome at the expense of some cycle complexity. Topics discussed include: bottoming plant definition; the bottoming steam cycle; the heat recovery boiler; multiple pressures; and combined cycle efficiency.

Steam regeneration of adsorbent - using indirect heat exchange of used steam with water in vaporiser reduces energy consumption

Abstract: Steam regeneration of adsorbent loaded with desorbable substances involves cooling the steam passed through the adsorbent in a vaporiser by indirect heat exchange the water, removing the steam formed by suction, so that it is at a pressure below that of the regeneration steam, and compressing this steam for use as a regenerating steam. The steam from the vaporiser is sucked through a compressor, pref. through a steam jet compressor by means of compressed fresh steam. In an example, insertion of the vaporiser into the cycle reduced the fresh steam requirement of a desorption process by 43%. The energy consumption in the generation of fresh steam is minimised.

Cross-Media Environmental Impacts of Air Pollution Regulations for a Coal-Fired Power Plant

Abstract: The types and rates of pollutant emissions from a coal-fired power plant depend upon plant design, coal characteristics, and environmental control policy. In the past, air pollution regulations were often promulgated without rigorous analysis of the resulting energy penalties and secondary environmental impacts that occur in other environmental media (air, land, or water), which are counterproductive to overall environmental quality. This paper describes a Comparative Assessment Model that has been developed to consider systematically such tradeoffs for conventional and advanced coal-to-electric technologies. The model is applied to quantify the secondary (“cross-media”) environmental and resource impacts resulting from alternative air pollution control policies that reduce sulfur dioxide emissions from a 1000 MW power plant. Multimedia pollutant burdens are presented, together with the increased requirements for coal, limestone, and water that are incurred in generating a fixed net quantity of electricit...

Installation for recovering energy from solid fossil fuels, more particularly bituminous coal high in inerts

Abstract: An installation for recovering energy from solid fossil fuels more particularly bituminous coal high in inerts consists of at least one unit in which the solid fuels are converted into gas. A gas-turbine and a steam-turbine are provided to recover the energy from the gases. The gases are freed of dust and desulfurized before the gas turbine. The installation is characterized in that a wet-bottom boiler using the ground fuel is provided with pressure firing, the flue gases therefrom being passed to a gas-gas heat exchanger, the desulfurizing unit and dust-removing unit before being utilized in the gas-turbine.