Including Start Up, Shut Down, Cleaning, Protective Or Maintenance Procedure Patents (Class 60/646)
  • Patent number: 4878348
    Abstract: A method and apparatus for continually monitoring the operating state of a set of governor valves (42,60) in a steam supply system for the first stage of a high pressure turbine during operation of the turbine, the system including a source including a throttle valve (40) for supplying steam at a defined pressure to the governor valves (42,60) and a plurality of nozzles (44) each connected to deliver steam from a respective governor valve (42,60) to a respective turbine inlet region, by the steps of: monitoring (52) the pressure at the outlet of each governor valve (42,60); monitoring (50,54) the pressure at the inlet to the throttle valve(s) (40) and at the turbine first stage; and comparing (56) the monitored outlet pressure of each governor valve (42,60) with the monitored pressure at the throttle valve inlet and at the turbine first stage in order to provide an indication of the operating state of each governor valve (42,60) and to detect and alert power plant operators of valve malfunctions or inefficien
    Type: Grant
    Filed: September 28, 1988
    Date of Patent: November 7, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: Daniel E. Fridsma
  • Patent number: 4873829
    Abstract: A steam power plant is shown which comprises a pressurized deaerating feed water tank, a high-pressure steam boiler, a high-pressure steam turbine, a low-pressure steam turbine, and a water-cooled, steam condenser, connected in series in a closed circuit. The condenser is maintained under a substantial pressure during operation and connected to supply feed water to the feed water tank. A steam-operated deaerator is connected to the feed water tank to remove air from the water therein. A steam jet is connected between and operable to move steam from the low-pressure turbine to the condenser. A steam jet is connected between and operable to move water from the condenser to the deaerator. A second steam jet is connected to the deaerator to provide steam to scrub the oxygen from the incoming water and permit introduction of a secondary steam source to provide heat as needed. A high-pressure, water injector is connected between and operable to move water from the feed water tank to the boiler.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: October 17, 1989
    Inventor: Anthony R. Williamson
  • Patent number: 4873827
    Abstract: A steam turbine plant comprising: (a) first, second and third turbines which are coaxially combined with each other; (b) a boiler for supplying high pressure steam to the first turbine; (c) first, second and third bypass means for selectively bypassing steam around the first, second and third turbines, respectively, wherein each of the bypass means comprises means for cooling the steam; (d) a condenser for condensing steam discharged from the third turbine; (e) means for forming a vacuum in the condenser; (f) a first reheater for reheating steam discharged from the first turbine and out of the first bypass means and supplying the steam to the second turbine; (g) a second reheater for reheating steam discharged from the second turbine and from the second bypass means and for supplying the steam to the third turbine; (h) first, second and third control valves for controlling steam flow rates flowing into the first, second and third turbines, respectively; (i) first, second and third bypass valves for controllin
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: October 17, 1989
    Assignee: Electric Power Research Institute
    Inventors: Yoshikazu Hadano, Eiji Tsunoda, Ichiro Kajigaya
  • Patent number: 4868754
    Abstract: An initial start-up schedule is prepared based on given parameters relating to a thermal power plant and its operation. A dynamic characteristic model is prepared, permitting simulation of start-up characteristics which would be obtained if the thermal power plant is started according to the initial start-up schedule. Estimates are made of specified parameters, such as energy loss, the time interval between steam admission to an intermediate pressure turbine and steam admission to a high pressure turbine, and thermal stress of the power plant. Determination is made of whether the estimated values of the selected parameters are within predetermined allowable ranges or not. The initial start-up schedule is then corrected according to a predetermined rule depending upon whether the estimated values are determined to be within the predetermined allowable ranges or not. The estimating, determining, and correcting are repeated until an optimized start-up schedule is obtained.
    Type: Grant
    Filed: April 2, 1987
    Date of Patent: September 19, 1989
    Assignee: Hitachi, Ltd.
    Inventor: Hiroshi Matsumoto
  • Patent number: 4866940
    Abstract: A method for automatically calibrating a controller for a valve controlled system follows consistent procedures to make precise adjustments to valve characteristics. The controller is placed in a calibration mode, then the valve settings are modified over a full range of operation. At predetermined levels of operation, the valve settings are maintained at preset values while system performance is measured. After the full range of valve operation has been covered, adjustments are made to the correspondence between the valve settings and the levels of operation in dependence upon the differences between the measured system performance and the predetermined levels of operation. This procedure is repeated to provide average values and also to make changes to valve characteristic curves corresponding to different modes of operation such as single valve and sequential valve modes. Other control parameters may be adjusted by evaluating system performance during normal operation.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: September 19, 1989
    Assignee: Westinghouse Electric Corp.
    Inventors: Edward Y. Hwang, Timothy D. Thomas
  • Patent number: 4825653
    Abstract: A method and apparatus for collection of water in a steam turbine exhaust system and in particular within a steam turbine exhaust pipe in which there is at least one turn or bend in the pipe and a plurality of substantially parallel turning vanes positioned in the bend for reducing undesirable flow characteristics in steam. The turning vanes extend across the pipe transverse to the direction of steam flow and are attached at opposite ends to a vane support ring embedded in the pipe wall. The invention includes forming a plurality of slots extending through the vane support ring for tranporting water from within the pipe to an external location. The slots are aligned on the vane support ring in an area corresponding to virtually zero pressure differential between each of the vanes and an adjacent vane. The slots preferably extend from a trailing edge of one of the vanes along the line normal to a tangent line to an adjacent vane on the low pressure side of the vane.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: May 2, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: George J. Silvestri, Jr.
  • Patent number: 4819435
    Abstract: A steam turbine power generation generation system includes a partial-arc stem turbine connected in driving relationship to an electric power generator and a boiler system for supplying steam at a predetermined pressure and temperature to the turbine. The boiler system includes a primary superheater, a serially connected division valve for controlling steam flow and pressure and a finish superheater. The turbine system includes a plurality of control valves for controlling steam admission to each partial-arc and a microcomputer base control means for controlling operation of the control valves and the division valve in response to load demands on the system so as to maintain constant speed operation of the steam turbine.
    Type: Grant
    Filed: July 11, 1988
    Date of Patent: April 11, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: George J. Silvestri, Jr.
  • Patent number: 4811566
    Abstract: A method and apparatus for removing liquid entrained by steam flow through crossunder piping in a turbine installation. The apparatus includes an insert, housed within the piping, having a diverging inlet portion and a substantially cylindrical outlet portion of equal inside diameter as the piping. In such manner, the insert and its housing form an annular-shaped collection chamber from which liquid is removed by a drain pipe.
    Type: Grant
    Filed: August 21, 1987
    Date of Patent: March 14, 1989
    Assignee: Westinghouse Electric Corp.
    Inventors: George J. Silvestri, Jr., Homer G. Hargrove
  • Patent number: 4811565
    Abstract: A steam turbine inlet valve control system includes separately tunable valve characteristics for single valve and sequential valve operation modes. The sequential valve characteristics include both normal and alternate sequences which can be selected during operation of the steam turbine. The characteristics may be displayed to an operator and modified by graphical manipulation to simplify tuning the control system's characteristics to the steam turbine's operation. The control system also performs direct tracking of flow through the valves by converting sensed position signals to individual valve flow signals using a lift-to-flow conversion characteristic. Individual valve flow signals are summed and corrected for choked flow conditions to produce a tracked flow demand signal.
    Type: Grant
    Filed: February 5, 1988
    Date of Patent: March 14, 1989
    Assignee: Westinghouse Electric Corp.
    Inventor: Edward Y. Hwang
  • Patent number: 4811196
    Abstract: The system and method of the present invention calls for reducing steam from one pressure down to a second pressure. Further, the steam st the one pressure is mixed with the steam at the second pressure. The mixed steam is provided for use in a process. The mixing of the steams is controlled in accordance with the providing of the mixed steam.
    Type: Grant
    Filed: January 15, 1987
    Date of Patent: March 7, 1989
    Assignee: Texaco Inc.
    Inventors: Marc D. McConnell, Richard R. Edwards
  • Patent number: 4803841
    Abstract: A mosture pre-separator for the exhaust from a steam turbine, having an exhaust nozzle, comprises three cylindrical conduits. A first cylindrical conduit is affixed to the annular wall of the nozzle and has a radially outwardly extending section adjacent the annular wall, with a second cylindrical conduit, which terminates short of the annular wall, contained therein to form a first collection chamber therebetween. A third cylindrical conduit is slidably positioned in the second cylindrical conduit and extends into the exhaust nozzle of the turbine and forms a second collection chamber between the outer wall thereof and the wall of the exhaust nozzle, with direct communication provided between the first and second chambers.
    Type: Grant
    Filed: September 30, 1987
    Date of Patent: February 14, 1989
    Assignee: Westinghouse Electric Corp.
    Inventors: Homer G. Hargrove, George J. Silvestri, Jr.
  • Patent number: 4793141
    Abstract: In order to recover the heat of the waste gas from a gas turbine, a waste heat recovery boiler is provided, which has a high-pressure steam generating portion consisting of an economizer, a high-pressure steam generator and a superheater, and a low-pressure steam generating portion consisting of an economizer, and a low-pressure steam generator. The steam from the high-pressure generating portion is supplied to the turbine through a high-pressure steam pipe, and the steam from the low-pressure steam generating portion to the same through a low-pressure steam pipe. The high-pressure gland sealing steam is supplied to a high-pressure side steam gland portion the steam turbine through a high-pressure steam extracton pipe branching from the high-pressure steam pipe, a steam pressure regulator adapted to regulate the steam pressure and introduce the excess steam to a condenser, and a high-pressure gland sealing steam pipe.
    Type: Grant
    Filed: November 13, 1987
    Date of Patent: December 27, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Eiji Yanai, Tsuguo Hashimoto, Kiyoshi Takeuchi, Takashi Asao, Yoshiki Noguchi
  • Patent number: 4792912
    Abstract: Thermal stress of a metal portion of a pressure-tight tube is calculated on the basis of calculated values of a temperature distribution calculator for calculating the distribution of temperature at positions equidistantly arranged in a direction of the thickness of the aforesaid tube on the basis of measured values of metal portion of the aforesaid tube, whereby the thermal stress being changed momently is accurately measured and monitored. Further, there is provided a calculation cycle setter for presetting calculation cycles on the basis of measured values of the fluid temperature in the aforesaid tube. The calculation cycles are made short when fluctuations in the measured values of the fluid temperature are large, while, the calculation cycles are made long when fluctuations in the measured values of the fluid temperature are small.
    Type: Grant
    Filed: April 24, 1985
    Date of Patent: December 20, 1988
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Atsushi Kuramoto, Yukio Fukayama, Shigeyoshi Kawano
  • Patent number: 4788823
    Abstract: A closed loop solar collector system (10) includes a fluid receiver (12) for collecting solar heat to vaporize a working fluid therein. A uniflow engine (15), connected to the receiver (12), is powered by the vaporized fluid to power a water wheel (19). The engine (15) includes a single piston (37) acting directly upon a pair of normally closed intake valves (50) projecting into the engine cylinder (35). Under low boiler pressure conditions, a spring loaded connecting rod (62) having depending arms (64) each engaging one of the intake valve rods (54b) when in a normally raised position coordinates simultaneous opening or closing of the valves (50) with a detent mechanism (63), enabling the piston (37) to operate in a nonexpanding state.
    Type: Grant
    Filed: September 22, 1987
    Date of Patent: December 6, 1988
    Inventor: Barry W. Johnston
  • Patent number: 4767263
    Abstract: A device for draining pressurized liquid from a steam turbine to a low pressure reservoir. The device comprises: an inlet container and an outlet container for storing liquid in their lower parts; drain lines for conveying liquid from the steam turbine to an upper part of the inlet container; a first pipe for maintaining the inlet container at a higher pressure than the outlet container with a head of a first liquid column which leads the liquid from the lower part of the inlet container to the upper part of the outlet container; and a second pipe for maintaining the outlet container at a higher pressure than the low pressure reservoir with a head of a second liquid column which leads the liquid from the lower part of the outlet container to the low pressure reservoir.
    Type: Grant
    Filed: October 8, 1987
    Date of Patent: August 30, 1988
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinya Ayano, Yasuo Ojiro
  • Patent number: 4744723
    Abstract: A thermal power plant includes a main system in which steam generated in a boiler passes, through a steam regulating valve, a high pressure turbine, a reheater and an intercept valve, into an intermediate pressure turbine and a low pressure turbine. The thermal power plant further has a high pressure bypass system bypassing the steam regulating valve and the high pressure turbine, and an intermediate and low pressure bypass system bypassing the intercept valve and the intermediate and the low pressure tubines. Upon starting the thermal power plant, the steam generated in the boiler is delivered, through the high pressure bypass system, the reheater and the intercept valve, into the intermediate and the low pressure turbines to accelerate the turbines, and after a sinchronous steam supply, the steam is delivered into the high pressure turbine through the steam regulating valve to increase a load imposed on the power plant instead of being delivered into the high pressure bypass system.
    Type: Grant
    Filed: March 2, 1987
    Date of Patent: May 17, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Tsuguo Hashimoto, Taiji Inui
  • Patent number: 4732004
    Abstract: In a process for purifying and deaerating the feed water line in the circulation system of a power-generating plant heated by nuclear power, the following steps are carried out in order to solve acute problems of steam-generator corrosion:(a) when the preheater train is filled, with the steam-generator isolating valve (40) closed, the condensate flows several times via a recirculation line (37, 52, 53) back to the condensate-collecting vessel (6) and to the condensate purification apparatus (9);(b) below the water level (7) in the condensate-collecting vessel (6), a deaerating medium (37,38,39) is introduced into the condensate via spray nozzles, rises in the condensate and forms in the deaerating chamber (44), as result of displacement of the air present in its, a cushion which is conducive to oxygen deaerating;(c) the steam produced during deaerating is precipitated in an additional condenser (48) which is located in the venting line upstream of the vacuum pump (47) and which is subjected to a secondary coo
    Type: Grant
    Filed: July 17, 1984
    Date of Patent: March 22, 1988
    Assignee: BBC Brown, Boveri & Company Limited
    Inventors: Andreas Brand, Helmut Lang
  • Patent number: 4726813
    Abstract: Metallic particles entrained in the flow of steam being supplied by a steam generator to a steam turbine, the metallic particles being entrained in the flow of steam and at least in part having exfoliated from boiler pipes of the steam generator, are deflected from an axially directed steam flow path outwardly, toward the outer circumference of the path at which they are trapped and collected and thereby removed from the steam flow supply to the turbine.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: February 23, 1988
    Assignee: Westinghouse Electric Corp.
    Inventor: Paul W. Viscovich
  • Patent number: 4703722
    Abstract: A boiler starting system for starting a boiler which has a superheater and at least two reheaters. The boiler starting system has a steam extracting line for extracting the steam from the steam inlet side or an intermediate portion of the superheater, and a steam supply valve by which the extracted steam is supplied to the reheaters. The flow rates of steam through the superheater and each reheater are controlled independently to realize optimum steam temperature rising characteristics, without requiring increase in the capacities of valves and other elements of the starting system.
    Type: Grant
    Filed: April 14, 1986
    Date of Patent: November 3, 1987
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventor: Yukio Fukayama
  • Patent number: 4688385
    Abstract: A method of starting a turbine having a shrinkage-fitted rotor provided by shrinkage-fitting discs onto a shaft comprises the steps of raising the temperature of the rotor above a predetermined temperature determined from a physical value of the material constituting the rotor and, thereafter, raising the rotational speed of the turbine from the turning speed to the rated speed, whereby the centrifugal stress on raising the speed acts on the discs in a state wherein the value of fracture toughness of the discs fitted on to the shaft has increased.
    Type: Grant
    Filed: January 23, 1985
    Date of Patent: August 25, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Naoaki Shibashita, Hajime Toriya, Kiyoshi Shimomura, Haruo Urushidani, Ryoichi Kaneko
  • Patent number: 4687626
    Abstract: The present invention provides a passive safety device for dumping steam from the steam generator of a nuclear power reactor in case of emergencies. The device comprises a steam ejector immersed in a storage tank of coolant water, a conduit connecting the steam ejector to the steam line from the steam generator, a heat exchanger having its inlet connected to the outlet of the steam ejector and the outlet to the storage tank, and a coolant pool in which the heat exchanger is immersed. Optionally, the output from the steam ejector may be connected to the feedwater line to the steam generator as an emergency feedwater supply.
    Type: Grant
    Filed: January 18, 1985
    Date of Patent: August 18, 1987
    Inventor: Long S. Tong
  • Patent number: 4679399
    Abstract: Apparatus and a method for protecting a steam turbine from damage due to moisture are disclosed. The temperature and pressure of the incoming steam are monitored to determine if sufficient superheat energy is available to assure that the steam will flow through the turbine in the gaseous phase. The same inputs may be utilized to determine under and over pressure steam conditions. Once a fault condition is detected, operation of the turbine will be automatically interrupted.
    Type: Grant
    Filed: September 13, 1985
    Date of Patent: July 14, 1987
    Assignee: Elliott Turbomachinery Co., Inc.
    Inventor: Roger D. Strickler
  • Patent number: 4674285
    Abstract: A reflux condensing start-up system comprises a steam generator, a start-up vessel connected parallel to the steam generator, a main steam line connecting steam outlets of the steam generator and start-up vessel to a steam turbine, a condenser connected to an outlet of the turbine and a feedwater return line connected between the condenser and inlets of the steam generator and start-up vessel. The start-up vessel has one or more heaters at the bottom thereof for heating feedwater which is supplied over a start-up line to the start-up vessel. Steam is thus generated to pressurize the steam generator before the steam generator is supplied with a heat transfer medium, for example liquid sodium, in the case of a liquid metal fast breeder reactor. The start-up vessel includes upper and lower bulbs with a smaller diameter mid-section to act as water and steam reservoirs.
    Type: Grant
    Filed: October 29, 1984
    Date of Patent: June 23, 1987
    Assignee: The Babcock & Wilcox Company
    Inventors: Oliver W. Durrant, Chandrasekhara R. Kakarala, Sheldon W. Mandel
  • Patent number: 4666662
    Abstract: A steam generator recirculating system for use with the secondary coolant of the steam generators of a pressurized water nuclear reactor is comprised of two separate recirculation loops. Each loop contains a common discharge line into which a secondary coolant discharge line and blowdown discharge line from at least one steam generator feeds. The common discharge line contains a recirculating pump and a heat exchanger, with bypasses provided about each. The common discharge lines discharge into branch feedlines back to the steam generators. The system may also be used as a blowdown system leading to a steam generator blowdown processing system and may include a water purification means and used to purify the secondary coolant water. Cross-connecting lines are provided to permit optional use of a particular loop with various steam generators.
    Type: Grant
    Filed: July 10, 1984
    Date of Patent: May 19, 1987
    Assignee: Westinghouse Electric Corp.
    Inventors: Robert A. Loose, James S. Schlonski, Claude C. Steinkuhler
  • Patent number: 4665706
    Abstract: A system for the operation of once-through boilers which utilizes variable throttle pressure over a very wide load operating range is disclosed. The system utilizes a valving arrangement permitting the turbine valve (22) to be opened to a predetermined open position, typically 70 percent of its full open position, as soon as possible during the system loading process, maintaining the turbine valve (22) in this predetermined open position while the flow of steam from the boiler is being varied by a control valve (40) and the output pressure of the boiler is varying accordingly, and then allowing the turbine valve (22) to open further from the predetermined open position when the system reaches full design pressure so as to vary the flow of steam from the boiler while the output pressure thereof is maintained substantially constant. In this manner, the boiler is operated at a variable output pressure over a very wide load operating range.
    Type: Grant
    Filed: August 21, 1985
    Date of Patent: May 19, 1987
    Assignee: The Babcock & Wilcox Company
    Inventors: Thomas D. Russell, Robert R. Walker
  • Patent number: 4658589
    Abstract: An ejection system including a steam ejector 48 having a steam nozzle 54 aligned with a diffuser 56 which defines a outlet from the ejection system. The ejector has an inlet 46, 52 to the interface of the nozzle 54 and the diffuser 56. A normally closed, non-condensible flow control valve 24 has an outlet 36 connected to the ejector inlet 46 and an inlet 32 adapted to be connected to a working fluid flow path 30 of a Rankine cycle apparatus. A motor 40, 42 is provided for selectively operating the flow control valve 24. A steam generating reaction chamber 60 is in fluid communication with the steam nozzle 54 and first and second pressure vessels 62, 64 are provided and adapted to contain a different reactant of a multi-reactant steam producing chemical reaction. A valve 66 controls fluid communication between the pressure vessels 62, 64 and the reaction chamber 60.
    Type: Grant
    Filed: March 21, 1986
    Date of Patent: April 21, 1987
    Assignee: Sundstrand Corporation
    Inventor: Thomas A. Sutrina
  • Patent number: 4655041
    Abstract: A method and apparatus for protecting a turbine from undesirable temperature and pressure variations wherein an acceptable range of actual pressure and temperature variations is established, a first alarm signal is generated only if the acceptable range is exceeded by actual temperature or pressure, a second signal is established representing an acceptable rate of change of said actual pressure or temperature and a second alarm is generated if the actual rate of change of pressure or temperature exceeds the acceptable range of pressure or temperature whereby the second alarm signal is produced only when the first alarm signal is generated. In addition, a third signal is established representing a maximum rate of change of pressure and a third alarm signal is generated if the actual rate of change of pressure or temperature exceeds the maximum rate of change of pressure or temperature whereby the third alarm signal is produced only when the first alarm signal is generated.
    Type: Grant
    Filed: January 21, 1986
    Date of Patent: April 7, 1987
    Assignee: Dresser Industries, Inc.
    Inventors: Richard J. Del Vecchio, James A. Gram
  • Patent number: 4651532
    Abstract: In a reheat turbine employing an intermediate pressure steam turbine starting system, a former stage (10a) of a high pressure steam turbine (10) is warmed up by a high temperature steam during the starting of an intermediate pressure steam turbine (50) while a latter stage (10b) of the high pressure steam turbine (10) is kept in vacuum. The high temperature steam is introduced through a warm-up steam valve (75) branched off from a steam pipe (43) for steam inflowing into an intermediate pressure turbine steam chamber (29). The high temperature steam that has warmed up several stages reaches a latter stage (10b) and is discharged into a condenser (54) through a ventilation valve (85) and a steam pipe (87). The former stage (10a) is positively warmed up by the high temperature steam to reduce the mismatch quantity. The high pressure steam turbine (10) is maintained warming up by the high temperature steam and cooling by vacuum during the start of the intermediate pressure steam turbine (50 ).
    Type: Grant
    Filed: April 11, 1986
    Date of Patent: March 24, 1987
    Assignee: Hitachi, Ltd.
    Inventor: Shoji Abe
  • Patent number: 4651530
    Abstract: A method and an apparatus for feed-water control in a steam generating plant such as a boiling water nuclear reactor having motor-driven feed-water pumps and turbine-driven feed-water pumps for supplying feed-water to a steam generator, in which the feed-water flow through the turbine-driven feed-water pumps is controlled to be maintained constant, while reducing the recirculation flow discharged from the turbine-driven feed-water pumps and fed back to the inlet thereof, so as to reduce the amount of feed-water supplied to the steam generator by the motor-driven feed-water pumps, whereby variation of water level in the steam generator during switching between the two kinds of feed-water pumps is suppressed.
    Type: Grant
    Filed: March 26, 1982
    Date of Patent: March 24, 1987
    Assignee: Hitachi, Ltd.
    Inventor: Takashi Omori
  • Patent number: 4651533
    Abstract: A steam turbine power plant having a feedwater heater, a boiler, a steam turbine driven by steam generated in the boiler, and a condenser for condensing steam exhausted from the steam turbine. An extracting steam pipe is provided which includes a control valve for extracting a steam from the steam turbine to the feedwater heater, with a controller being provided for controlling an amount of the extracting steam in order to control a feedwater temperature flowing through the feedwater heater at an adequate range when the plant is starting or stopping. By controlling the feedwater temperature, a thermal stress generated in the feedwater heater is reduced to below an allowable value so that it is possible to increase the working or service life of the feedwater heater and improve the reliability of the steam turbine plant while reducing the maintenance costs thereof.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: March 24, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Katsumi Ura, Kenji Sakka, Yosimi Kouno, Taiji Inui
  • Patent number: 4635209
    Abstract: In a steam turbine control system three overspeed protection circuits (OPC) are provided, each one being identical to the others and each having a programmable digital computer in two-way data communication with a master controller, as well as with the other OPCs. Speed transducers adjacent the turbine shaft provide speed indicative signals to the respective OPCs which calculate extremely precise RPM values utilizing an adaptive filter in the derivation process.
    Type: Grant
    Filed: October 31, 1984
    Date of Patent: January 6, 1987
    Assignee: Westinghouse Electric Corp.
    Inventors: Eddie Y. Hwang, Wu-Shi Shung
  • Patent number: 4606192
    Abstract: A solar electric power generating process is described which consists of tapwater thermally contacted with special brine. Low pressure characteristics of the brine draw steam through a power-generating turbine from the water into the brine. As the brine is pumped over an open air evaporator, excess water picked up by the brine is driven off using solar or waste heat. The tapwater is first purified in a demineralizer.
    Type: Grant
    Filed: August 14, 1985
    Date of Patent: August 19, 1986
    Inventor: William G. Brown, II
  • Patent number: 4598551
    Abstract: A steam turbine-generator system includes a reheater bypass valve which cooperates with both a high- and low-pressure bypass valve in the early stages of turbine loading to divert steam in a bypass flow from a high-pressure turbine to the input of a reheat turbine without passing the steam through a reheat portion of the boiler. The pressure and temperature drops in the high-pressure turbine are controlled by the setting of the pressure threshold of the low-pressure bypass valve. A check valve prevents steam flow into the reheat portion of the boiler until a desired operating condition is attained. The steam flowing to the reheat turbine directly from the high-pressure turbine is at a sufficiently low temperature to avoid temperature insult to the rotor of the reheat turbine. Once the turbine is partially loaded, the reheater bypass, high-pressure bypass and low-pressure bypass valves are closed to establish a conventional reheat turbine configuration.
    Type: Grant
    Filed: October 25, 1985
    Date of Patent: July 8, 1986
    Assignee: General Electric Company
    Inventors: Vladimir T. Dimitroff, Jr., James B. Wagner
  • Patent number: 4589255
    Abstract: The invention relates to a combined heat recovery steam generator and steam turbine. An adaptive temperature controller establishes a target temperature for controlling the boiler temperature so that the steam admitted on the boiler follows a constant enthalpy when trying to match temperature of steam and rotor temperature.
    Type: Grant
    Filed: October 25, 1984
    Date of Patent: May 20, 1986
    Assignee: Westinghouse Electric Corp.
    Inventors: Alan Martens, Gerry A. Myers
  • Patent number: 4584836
    Abstract: A restart temperature maintenance system and method for a steam turbine system is disclosed. The restart system utilizes a plurality of electric heating blankets maintained over an air gap to maintain the temperature of the turbine rotor at a desired initial start-up temperature thereby greatly decreasing the time required for warm-up.
    Type: Grant
    Filed: January 29, 1985
    Date of Patent: April 29, 1986
    Assignee: Westinghouse Electric Corp.
    Inventor: Thomas R. McClelland
  • Patent number: 4584837
    Abstract: A method of and apparatus for deaerating condensate in a power generating steam turbine plant of the type having deaeration system making use of the deaeration function of the condenser of the plant. The non-deaerated condensate in the condenser of the steam turbine plant to be started is substituted by deaerated condensate supplied from an equipment containing deaerated condensate such as the condenser of another plant under operation and deaerated condensate storage tank. The non-deaerated condensate can be deaerated in a short period to the level required for the feedwater supplied to the boiler, of the steam turbine plant.
    Type: Grant
    Filed: October 12, 1983
    Date of Patent: April 29, 1986
    Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.
    Inventors: Kenji Sakka, Taiji Inui, Ryoichi Okura, Masao Kanazawa, Yasushi Takeda
  • Patent number: 4583369
    Abstract: In a steam power plant, a system is provided for early detection of a rupture or extensive leak from the feedwater tubing in the feedwater heaters. The system senses the temperature and pressure in the steam space of each feedwater heater. A pressure rise followed by a temperature drop in the steam space of a feedwater heater is recognized as being caused by a rupture or extensive leak in the feedwater heater and in response to such occurrance, an alarm is activated and a power assisted check valve is closed in the extraction line feeding extraction steam from the turbine to the feedwater heater.
    Type: Grant
    Filed: May 9, 1985
    Date of Patent: April 22, 1986
    Assignee: Factory Mutual Research Corporation
    Inventor: Mark A. Shapiro
  • Patent number: 4578954
    Abstract: In a recycling steam system, a flow of waste steam is retrieved from the power cycle at a pressure in excess of condenser pressure and directs this waste-steam flow into a network of pipes vertically suspended in and distributed throughout the hotwell condensate, the pipes being so vertically elongate and so perforated within the region of condensate immersion that differences between instantaneous waste-steam pressure and instantaneous condenser pressure are automatically accommodated, in the form of greater or lesser scrubbing discharges of the waste steam into the accumulated volume of condensate which serves the condensate-return part of the system.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: April 1, 1986
    Assignee: Transamerica DeLaval Inc.
    Inventor: Michael J. Lenhardt
  • Patent number: 4576124
    Abstract: A coupling controller opens a dump valve at the outlet of a heat recovery steam generator when such generator is to be coupled to another generator being in operation with a steam turbine on a common header. The controller gradually permits pressure build-up until the pressure at the outlet of the new generator matches the pressure behind the header. The controller also responds to critical conditions in the superheater as well as in the high pressure drum of the generator in the operation.
    Type: Grant
    Filed: October 25, 1984
    Date of Patent: March 18, 1986
    Assignee: Westinghouse Electric Corp.
    Inventors: Alan Martens, Kermit R. Wescott, Bennie E. Snow
  • Patent number: 4558228
    Abstract: The invention concerns an energy converter, comprising a boiler, a turbine (11), a condenser, a feed pump (16) and a generator (17) and, if required, a recuperator and a pre-feeding pump. The thermal energy to be supplied to the boiler has been arranged to maintain a Rankine process driving the generator (17) and thus to produce electricity. The turbine (11), the generator (17) and the feed pump (16) have a joint rotor shaft (36). The rotor (36) is rotatably carried with gas-dynamic bearings (24) utilizing the circulating fluid's vapor. The lower surface of the rotor (21) of the turbine (11) has been disposed to serve as one abutment surface of a gas-static thrust bearing (22). The gas-dynamic bearings (24) are bearings of tilting pad type.
    Type: Grant
    Filed: June 6, 1983
    Date of Patent: December 10, 1985
    Inventor: Jaakko Larjola
  • Patent number: 4558227
    Abstract: A method of controlling the operation of a thermoelectric power generating plant, in which the operation of the steam generating equipment and the turbine is controlled in accordance with the plant operation parameters obtained from given patterns of start up and operation of the plant.
    Type: Grant
    Filed: June 8, 1984
    Date of Patent: December 10, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Sadao Yanada, Naganobu Honda, Hisanori Miyagaki, Seiitsu Nigawara
  • Patent number: 4554788
    Abstract: Hydraulically operated turbine steam admission valves wherein each valve has its own microcomputer control. In the event the valve gets stuck due to possible contamination in the hydraulic system, the microcomputer control provides an oscillatory control signal to dither the valve. If the valve remains stuck after dithering action it is provided with a control signal of an initial magnitude greater than that normally required to close the valve.
    Type: Grant
    Filed: December 21, 1983
    Date of Patent: November 26, 1985
    Assignee: Westinghouse Electric Corp.
    Inventors: Eddie Y. Hwang, Andras I. Szabo, Wu-shi Shung
  • Patent number: 4535593
    Abstract: A method of and apparatus for warming high-pressure feed water heaters for power plants provided with a boiler having a circulation system, in which a part of high-temperature water flowing in the circulation system is separated therefrom to introduce the resulting feed water into a high-pressure feed water heater from the portion of a feed water system which is on the side of an inlet portion thereof, with the feed water flowing out from the heater returned to the boiler, during a period of time which is between an instant, at which the boiler is ignited, and an instant, at which the heater is put in service, the heater being thereby warmed, a flow rate of the feed water introduced from the boiler to the heater being controlled in accordance with the temperature of the feed water flowing down in the same heater, whereby the occurrence of an excessively high thermal stress in the heater can be prevented when the heater is put in service.
    Type: Grant
    Filed: August 23, 1982
    Date of Patent: August 20, 1985
    Assignee: Hitachi, Ltd.
    Inventor: Kenji Sakka
  • Patent number: 4534320
    Abstract: A method for determining the amount of dissolved oxygen in the aqueous medium from a steam generator system that results from air leakage into the system above the water level in a condensor hotwell and that which results from air leakage below the water level in the condensor. Intentional injection of air above water level and intentional injection of air below water level are effected and resultant dissolved oxygen contents measured. The air leakage rate and dissolved oxygen contents at steady state operation are also measured. From these measurements, the amount of dissolved oxygen resulting from above and below water level are determined mathematically or graphically.
    Type: Grant
    Filed: March 1, 1984
    Date of Patent: August 13, 1985
    Assignee: Westinghouse Electric Corp.
    Inventors: Alexander D. MacArthur, Harry J. Everett
  • Patent number: 4526510
    Abstract: A hot gas centrifugal fan is constructed with a scroll part comprising spaced-apart walls 16 and 18 to define a hot gas passage 22 therebetween to which hot gas is conveyed when the fan is in a non-operating condition to hold the fan temperature sufficiently high to avoid unacceptable vibration brought on by thermal distortion of the fan wheel upon a re-start of the fan.
    Type: Grant
    Filed: March 7, 1983
    Date of Patent: July 2, 1985
    Inventors: Joseph H. Hoffman, Steven R. Thayer
  • Patent number: 4523432
    Abstract: In an air storage power station heat is withdrawn from the compression process via a heating element (18) and passed into a heat storage device (15). During turbine operation the cold compressed air taken from the air reservoir (1) is first pre-heated with the stored heat in an air heater (21) and then passes via the recuperator (14) to the gas turbine (12',12"). In this way low-temperature corrosion at the exchange surfaces of the recuperator (14) on the flue gas side is avoided, especially during start-up of the gas turbine.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: June 18, 1985
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Hans-Ulrich Frutschi
  • Patent number: 4514642
    Abstract: A control system is provided for controlling the distribution of load among a plurality of generators with some of those generators responding quickly to control and some being slow in response. The area control error signal is divided into portions to provide a unit error signal assigned to each generator. A control is utilized which responds to the unit error signal to reposition the governor motor until the error signal is reduced to zero. Applying that control to slow responding units requires anticipation of the generation changes to be expected after full response. Control of the governor motor position so as to modify generation is from the unit error signal as modified in accordance with the difference between the desired generation for the units as required for economic considerations and the actual generation with that difference being modified by a signal which is a function of the anticipated generation. That function is expressable in one form by the equation ##EQU1## where: K is a constantP.sub.
    Type: Grant
    Filed: February 4, 1983
    Date of Patent: April 30, 1985
    Assignee: General Signal Corporation
    Inventor: Charles W. Ross
  • Patent number: 4512851
    Abstract: This process separates less volatile contaminates from thermal power recovery systems utilizing a volatile working fluid in a cyclic closed system; such a system may comprise a reservoir, a pump, a heater, a separator, a throttle device, a turbine and a condenser. The purification can be accomplished during start-up, shut-down or periods of low power generation. The contaminant is separated from the working fluid in the separator in which the temperature and pressure correspond to a dew-point substantially above that of a sample of uncontaminated working fluid. To achieve this condition, the normal flow of liquid from the reservoir to the heater is reduced and the heater and throttle device are correspondingly adjusted. The condensed contaminant is removed from the separator while substantially all of the working fluid which has been vaporized is passed on through the throttle device to the turbine.
    Type: Grant
    Filed: February 15, 1983
    Date of Patent: April 23, 1985
    Inventor: Judson S. Swearingen
  • Patent number: 4505824
    Abstract: A method of and apparatus for purifying a liquid which contains magnetic solid particles therein, includes a system for feeding the liquid to a container of an electromagnetic filter including a matrix disposed inside the container and a coil disposed so as to encompass the outer circumference of the container and generating a line of magnetic force to magnetize the matrix when a current is applied thereto. The coil is cooled by diverting the purified liquid from a downstream side of the matrix.
    Type: Grant
    Filed: October 18, 1982
    Date of Patent: March 19, 1985
    Inventors: Kazuhiko Akamine, Katsuya Ebara, Kazuyuki Ito, Shinji Mitani
  • Patent number: 4487166
    Abstract: A start-up system for once-through boilers including the reduction of minimum flow during start-up to 15% full load by the use of multi-lead internal ribbed tubing to the enclosure tubes in the high heat input zones, the use of a variable pressure by-pass stop valve in the main flow path, a pressure reducing means in the by-pass system and two steam spray attemperators from the flash tank or separators. The first steam attemperation is to the outlet of the secondary superheater and the second to the outlet of the reheater.
    Type: Grant
    Filed: September 12, 1983
    Date of Patent: December 11, 1984
    Assignee: The Babcock & Wilcox Company
    Inventors: Kurt H. Haller, Carl Lieb, Pete G. Todoroff