Abstract: Disclosed herein is a steam engine suitably constructed to serve as a prime mover. The device includes a furnace in which a liquid can be heated so as to change its phase, the thus formed gas directed to an engine whereupon its expansion within piston/cylinder arrangements provides useful work. The exhausted steam, still endowed with extractable energy, is passed through various regenerative pump mechanisms and the like for very efficient utilization of much of the inherent energy.
Abstract: A turbine system which includes a reheater upstream from a low pressure turbine which is subject to corrosive salt depositions from the steam. Conductance probes are inserted at predetermined positions within the low pressure turbine and based on the conductance signals the reheat temperature or load is varied so as to move the corrosive salt deposition zone away from a rotating blade stage of the low pressure turbine.
October 15, 1980
Date of Patent:
June 7, 1983
Westinghouse Electric Corp.
Pang-Kai Lee, William M. Hickam, William G. Steltz
Abstract: A boiler feed pump turbine system wherein the feed pump turbine speed is controlled by a signal locally generated by an operator up to a certain minimum speed and thereafter by a signal automatically commanded by a boiler feedwater control system. During operation within a certain speed range in which the signal from the boiler feedwater control system is controlling, a locally generated signal in the feedpump turbine control signal is caused to track the boiler control system signal so that in the event of failure thereof, the feed pump turbine may be controlled by the locally generated signal as opposed to reducing its speed to zero as would normally be dictated by the failed signal.
Abstract: Various control methods and means are disclosed for varying the temperature of vaporization of a solar-powered system so that the instantaneous power delivered by the heat engine of this system, or by a device driven by this engine, is a maximum for given conditions external to the power system, or to the power system and the driven device, respectively, while ensuring that dry saturated vapor, or vapor with a preselected amount of superheat is supplied to the heat engine.The power system uses a Rankine power cycle whose working fluid is either vaporized in the absorber of a solar collector, or in a heat exchanger by a separate fluid which absorbs heat by flowing through the solar collector absorber.Also, various methods and means are disclosed for controlling the foregoing separate heat-transfer fluid so that it absorbs sensible and latent heat in the absorber of the solar collector in essentially the same ratio as the power-cycle working fluid absorbs sensible and latent heat from this heat-transfer fluid.
Abstract: A control system for a steam turbine operated with a steam bypass system. In the control system, bypass valve control is according to setpoints generated as a function of a combined flow reference (CFR) signal. The CFR signal is representative of boiler outlet flow under all turbine operating phases and is generated by multiplying the sum of the steam admission control valve flow demand and the high pressure bypass flow demand by boiler pressure. An actual load demand (ALD) signal indicative of the turbine demand for steam is produced from the product of the steam admission control valve flow demand and boiler pressure, and is used for intercept valve control. Excessive steam flow in the lower pressure bypass subsystem is prevented by providing an override for the normal control to prevent high heat impact to the condenser and latter stages of the turbine high pressure section.
Abstract: A side stream type condenser which has a first hot well for condensing steam exhausted from a turbine and storing the condensed water and a second hot well for storing the purified condensed water to prepare for water feed to a main system includes a partition plate for defining the two hot wells. The partition plate is formed with a weir portion so that part of the condensed water in the second hot well may overflow to keep a fixed water level. The weir portion is constructed in the shape of a labyrinth and is formed with a passage normally filled up with the condensed water, and a space in the upper part of the second hot well communicates with the upper space of the first hot well through this passage only. The condensed water in the first hot well is fed to a purifying system disposed outside, and is purified therein.
Abstract: A solar energy plant comprises a solar energy boiler having pre-heating, evaporation, and superheating stages, and a control system for maintaining constant the temperature and the volume of the superheated steam at the boiler outlet upon variations in the incident solary energy. The flow of water entering the boiler is divided into a main flow, passing through the preheating, evaporation and superheating stages, and a secondary water flow. A first part of the secondary water flow is injected directly into the evaporation stage and a second part of the secondary water flow is injected directly into the superheating stage. The control system includes valve means for varying the rate of flow of the main water flow, and the first and second parts of the secondary water flow such as to maintain constant the temperature of the output superheated steam.
Abstract: A method is disclosed for improving the operational efficiency of a steam turbine power plant by governing the adjustment of the throttle steam pressure of a steam turbine at a desired power plant output demand value. In the preferred embodiment, the impulse chamber pressure of a high pressure section of the steam turbine is measured as a representation of the steam flow through the steam turbine. At times during the operation of the plant at the desired output demand value, the throttle pressure is perturbed. The impulse chamber pressure is measured before and after the perturbations of the throttle pressure. Because changing thermodynamic conditions may occur possibly as a result of the perturbations and provide an erroneous representation of the steam flow through the turbine, the impulse chamber pressure measurements are compensated for determined measurable thermodynamic conditions in the steam turbine.
Abstract: The invention provides a method for operating a power generating assembly which assembly comprises a steam generator and a turbine, and said method comprises controlling the quantity of heat released by the steam generator by a signal which is representative of the difference between the predicted stresses which will exist at the instant to+T on that part of the turbine which undergoes the greatest thermal stress and the maximum permissible stress on this same part at the same instant, to being the present instant and T being a period of time close to the time constant of the power production assembly.
Abstract: A method and means for controlling the throttle pressure of a fuel fired drum type boiler by controlling the fuel input to the boiler so as to equalize the boiler demand, calculated as the product of a quantity proportional to the rate of energy output from the boiler at the existing throttle pressure times the ratio of the desired throttle pressure to the existing throttle pressure, and the heat released to the boiler by the fuel, calculated as the sum of a quantity proportional to boiler output and the measured rate of change of drum pressure.
Abstract: A method of electrical power generation is disclosed wherein the energy source to operate the said electrical power generation apparatus is that energy existing between two fluid sources being at different temperatures and therefore at different energy levels. These fluid sources could be as divergent as warm underground crude oil as it is pumped from wells and the cooler atmospheric air above the said oil wells, or as intimately related as the warm water output from conventional and nuclear power generating plants and the cooling water source usually available to such generating plants. Warm water pumped from deep below the earths surface, geo-thermally heated, as the warm or hot source and surface water from lakes, oceans, rivers, etc. as the colder, or lower energy source provides an additional source of energy for the method of electrical power generation herein described.
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.
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.
Abstract: The boiler feed water system is provided with a motor driven feed water pump and a steam turbine driven feed water pump. The control system comprises a digital computer including a flow quantity control system responsive to the degree of opening of a flow control valve and the discharge quantity of the motor driven feed water pump for controlling the flow quantity thereof, and a speed control system responsive to the speed and discharge flow quantity of the steam turbine driven feed water pump, head pressure of the feed water system and the operation of a control motor for a steam control valve of a pump driving turbine. The control is switched between the flow quantity control system and the speed control system in accordance the load of the plant.
Abstract: In a steam turbine-generator with means for determining a load demand signal in accordance with a load reference signal, means for determining the valve opening under each admission mode of full-arc and partial-arc in accordance with said load demand signal and means for adjusting the ratio between valve openings under the each admission mode in accordance with a load change the ratio of steam flow under each of the admission modes is controlled in accordance with a load change so as to minimize the thermal stresses and thereby reduce the turbine load changing time.
Abstract: A vapor generator supplies vaporized motive fluid to a prime mover which drives a load. In the embodiment of this disclosure the primary load is the electrical load on an alternator. A sensor provides a continuous signal representative of the load. Responsive to this signal the flows of motive fluid and fuel and air to the vapor generator are modified. Additional modifications to the flows are made responsive to signals representing the temperature and pressure of the vapor leaving the vapor generator.
January 2, 1976
Date of Patent:
September 26, 1978
General Electric Company
Leslie H. Boerstler, Walter V. Discenza, Jr., Mason D. Marvin, Theodore J. Ebersole
Abstract: A hybrid power system comprising a pair of energy converters operating on a closed Rankine cycle, each energy converter having a vapor generator for vaporizing a high molecular weight working fluid in response to heat furnished from a burner associated with the generator, a turbo-generator responsive to vaporized working fluid for generating electrical power, a condenser responsive to the exhaust vapors from the turbo-generator for converting such vapors into a condensed liquid, and means for returning the condensed liquid to the vapor generator; sensors for sensing the electrical output of the turbo-generator of each converter; and a control system responsive to the sensors for controlling the burners in the converters so that each converter furnishes about half the electrical load on the system in normal operation thereof; one of the converters, termed the primary converter, operating with a working fluid having a higher boiling point than the working fluid in the other converter which is termed the seconda
Abstract: The temperature and pressure of the vapor generated in a vapor generating unit are so controlled that a fuel supply valve is opened for fuel delivery when the temperature or pressure drops below a predetermined lower limit and is closed when the temperature or pressure exceeds a predetermined upper limit, provided that a vehicle operator manipulable throttle valve is substantially in a fixed position. As the throttle valve is abruptly moved, an acceleration or deceleration signal opens or closes the fuel supply valve independently of the actual vapor temperature and pressure.
Abstract: A line is connected to a branch point between the gas-heated preheater and evaporator to deliver heated feed water to the supply tank while control valves are placed in the feed line to the preheater and the line to the supply tank. These valves are controlled by a temperature measuring means adjacent the branch point. If the measured temperature increases, the flow of feed water to the preheater increases.
Abstract: A method of optimizing the performance of a multi-unit power plant which produces both electrical and steam energy by determining the incremental efficiency of power boilers with various fuel inputs and thereafter determining the index of performance by taking into account cost factors and reallocating in the most optimum manner.
Abstract: A steam turbine-generator power plant is described wherein solar energy is used to preheat feedwater to a steam generator. Two parallel feedwater supply branches are proposed for preheating the feedwater upstream from the steam generator. A first preheater branch utilizes extraction steam from the steam turbine for preheating feedwater and is called an extraction branch. A second preheater branch utilizes solar energy for preheating feedwater and is called a solar branch. The two branches are joined upstream from the steam generator and the proportion of flow from each branch is based on the temperature difference between the extraction branch and the solar branch. A variable speed pump is used to pump feedwater from the solar branch at a rate proportional to the temperature difference between the two branches.
Abstract: A boiler control regulates the input fuel and air to satisfy load demand. Simultaneously, fuel flow is adjusted by fuel flow control to correct for changes in fuel heating value. A computer circuit which generates a heat balance ratio of outlet steam flow and input mass fuel flow as a representation of imbalance between presumed heat input and actual heat output and by inference from the imbalance or change in fuel heating value. The heat balance ratio is multiplied against an actual fuel feedback signal and the ratio corrected signal is applied to the fuel flow control.
Abstract: A boiler control regulates the input fuel and air to satisfy load demand. Simultaneously, the air flow is adjusted by an air flow control to correct for changes in fuel heating value by means of a circuit which operates in response to outlet steam flow and input mass fuel flow to determine the difference in presumed heat input and actual heat output and, by inference from the heat imbalance or error, a change in fuel heating value. The heat error is used to adjust the air flow demand to the air flow control. In another embodiment, boiler heat pickup is derived to remove from the heat imbalance any heat input changes other than fuel heating value changes.
Abstract: A steam power plant includes a boiler unit heated by gas supplied from a pipeline for converting water into steam; the gas may be stored as reserve liquefied gas. A turbine is powered by the steam generated by the boiler unit, and the steam gives up energy to power the turbine; a condenser receives energy-depleted steam from the turbine and includes a cooling circuit with water circulation, and a storage facility for the reserve liquefied gas. A heat exchanger is used for regasifying the liquefied gas and at least a portion of the cooling circuit is in heat-exchange contact with the liquefied gas, so that the liquefied gas is regasified by way of step regasification and supplied to the boiler unit upon a deficiency of gas occurring in the pipeline.
Abstract: Apparatus for the control of steam-heating power plants to optimize the use of energy in producing the required steam and electrical power comprising means for sensing steam and electricity demands, means for comparing these sensed demands with the electricity and steam output of turbine means in the plant, and means for adjusting operating set points of the turbines and steam generator for coordinated control of power plant energy consumption and production.
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. The steam generator includes a superheater tube through which a fluid, e.g. water, is directed to be additionally heated into superheated steam by the exhaust gas turbine gases. An afterburner further heats the exhaust gas turbine gases passed to the superheater tube. The temperature of the gas turbine exhaust gases is sensed for varying the fuel flow to the afterburner by a fuel valve, whereby the temperatures of the gas turbine exhaust gases and therefore of the superheated steam, are controlled. Further, override signals are generated to prevent the temperature of the superheated steam from falling below a predetermined minimum level and for preventing the temperature and pressure of the superheated steam from exceeding maximum levels.
Abstract: In a steam engine, an intermediate phase is provided for preheating the feedwater before it enters the boiler. The preheating is achieved by means of the reapplication of the otherwise dispensable exhaust steam in a simple feedback operation in which the exhaust steam is introduced directly into the feedwater. By means of electronic controls the operation of the system at the highest possible point of preheat (up to 210.degree. F.) is achieved thus assuring both high efficiency of the machine and cumulative economy in fuel consumption as well. The latter is further augmented by generous application of insulation to prevent wasteful dissipation of thermal energy as well as to effect protection of the system against the elements.
Abstract: In a vehicle steam engine having a steam generating unit, a condenser, fluid pumps for supplying the condensed liquid and fuel to the steam generating unit, a plurality of bypass passages are connected between the input and output sides of each pump. An electromagnetic on-off valve is provided in each bypass passage. Sensors are connected to the steam generating unit to detect variations in temperature and pressure of the steam to provide corresponding electrical signals. Each of the sensed signals is compared with different critical levels to produce output signals at one of two discrete levels to open the bypass passages in stages to thereby regulate the flow rate of the fluid to the steam generating unit.
Abstract: A once-through boiler is provided with integral separators and a plurality of valves for controlling fluid flow during boiler startup. A pressure control generates an open or close signal for all of the valves and a sequence selector responds to the pressure control and a valve-in-operation logic circuit to generate valve selection signals which enable the valves to respond sequentially to the pressure control output.
Abstract: In a steam turbine plant with feed water heaters receiving steam extracted from the turbine to apply in heat exchange with the feed water being supplied to the boiler, the drain water level in the water heaters is monitored so that when the drain level exceeds a predetermined abnormal level, for example due to rupture of the feed water pipes in the feed water heater, steam supplied to the turbine is automatically reduced to runback the load on the turbine, and thereafter the extraction of the steam to the malfunctioning feed water heater from the turbine is stopped and the feed water heater is bypassed with respect to the feed water flowing to the boiler, so that the malfunctioning feed water heater is thus isolated from the turbine plant.
Abstract: A control system is disclosed for a high temperature gas cooled reactor power plant, wherein a steam source derives heat from the reactor coolant gas to generate superheated and reheated steam in respective superheater and reheater sections that are included in the steam source. Each of dual turbine-generators includes a high pressure turbine to pass superheated steam and an associated intermediate low pressure turbine to pass reheated steam. A first admission valve means is connected to govern a flow of superheated steam through a high pressure turbine, and a second admission valve means is connected to govern a flow of reheated steam through an intermediate-low pressure turbine. A bypass line and bypass valve means connected therein are connected across a second admission valve means and its intermediate-low pressure turbine.
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. A condenser receives the spent steam from the steam turbine for converting it into condensate. The steam generator includes a deaerator for receiving the condensate flow from the condenser and for storing it in a storage portion, a feedwater pump for directing the stored condensate through a first heat exchange tube whereby heat is transferred from the gas turbine exhaust gases to the fluid, a main drum for receiving and storing the heated fluid and a second heat exchange tube for heating the fluid by the gas turbine exhaust gases into superheated steam to be supplied to the steam turbine.
Abstract: An improved steam boiler system includes an automatic means for injecting cool water into a steam bound boiler feed pump. In a first embodiment a pressure sensitive check valve detects the drop of pressure in the steam bound pump and in response thereto directs a cool water mist into the high side of the pump, thus reinitiating its operation. According to a second embodiment, cool water is sprayed into the pump in response to a drop of the water level in the boiler. In both embodiments, a vent line is used to bleed the high side of the centrifugal pump to a condensate tank in response to a drop of pressure in the pump. The vent line may be bled through a check valve or directly through a manual valve. Additionally, both embodiments employ a pressure sensitive valve in the boiler feed line, which shuts off the pump flow to the boiler whenever the pressure in the boiler exceeds the pressure at the output of the pump.