摘要:
Drops of water in wet steam exiting a steam turbine are electrically charged. When exposed to a sufficiently strong electric field produced by suitably disposed electrodes (34,85), the electrically charged water drops disintegrate into numerous small droplets, which serve as nuclei for internal condensation. Supersaturation of the steam is decreased, thereby decreasing the amount of water in the vapor phase, the condenser pressure, and the turbine backpressure. Electrostatic forces acting upon the charged water droplets decrease turbulence in the wet steam flow, further decreasing backpressure. The result is an increase in energy conversion efficiency and power output at constant fuel rate. A method and device for providing this beneficial result are provided.
摘要:
Ammonia sometimes present in geothermal steam increases the solubility of hydrogen sulfide in the steam condensate produced by the surface condenser in a steam cycle geothermal power generating unit by reacting with the hydrogen sulfide to produce nonvolatile ammonium bisulfide. The condenser vent gas also produced contains carbon dioxide. Contacting the steam condensate with the condenser vent gas at a pressure slightly greater than atmospheric causes carbon dioxide to dissolve in the condensate, decreasing pH and converting bisulfide ion back to hydrogen sulfide. Subsequently exposing the acidified condensate to condenser vacuum strips the hydrogen sulfide from the condensate, eliminating the need for further chemical treatment of the condensate to prevent air pollution. Hydrogen sulfide partitioning performance is further improved by converting the hydrogen sulfide in the vent gas to sulfur dioxide before contacting it with the condensate.
摘要:
An electrode with large active surface area is made by winding a Ti-fiber tow around a rectangular Ti-plate, and an electrocatalytic coating of three layers is applied. A precoat comprising a mixture of iridium dioxide and tantalum pentoxide is applied first, using a solution of the corresponding chloride salts in hydrochloric acid with some nitric acid added to inhibit corrosion of the metal. A sealing coat is then applied, comprising tin dioxide doped with antimony, in order to improve adhesion of the final oxide coat to the precoat. The third and final coat comprises particles of titanium dioxide doped with niobium in the +4 oxidation cemented with titanium dioxide that is doped with antimony. Anodes of this description are preferably assembled together with corrosion resistant cathodes in an alternating sequence, with a plastic coated fiber glass mesh placed between the anodes and cathodes to prevent short circuiting. When a sufficiently large voltage is applied across the cell, organic substances dissolved in the electrolyte will be oxidized.
摘要:
Sufficient negative charge density may be present in the wet steam flowing through the exhaust hood of a steam power generating unit to cause intense electrical discharges which cause severe corrosion of exposed carbon steel members and generate turbulence, decreasing power output. The electric charge density is proportional to current from a charge probe exposed to the flowing steam to ground. Electric charge density can be controlled by adjusting the concentration of ammonia in the steam supply. A small positive charge density will eliminate corrosion and minimize turbulence related to electrical discharges, thereby increasing power generated. The amount of negative charge released can also be decreased by cladding the portions of the flow guides and other carbon steel members located near to the turbine exhaust with stainless steel, or with an appropriately chosen insulating composition. These improvements may be included in the design of a new power generating unit or provided by retrofitting an existing unit.
摘要:
Ammonia sometimes present in geothermal steam increases the solubility of hydrogen sulfide in the steam condensate produced by the surface condenser in a steam cycle geothermal power generating unit by reacting with the hydrogen sulfide to produce nonvolatile ammonium bisulfide. The condenser vent gas also produced contains carbon dioxide. Contacting the steam condensate with the condenser vent gas at a pressure slightly greater than atmospheric causes carbon dioxide to dissolve in the condensate, decreasing pH and converting bisulfide ion back to hydrogen sulfide. Subsequently exposing the acidified condensate to condenser vacuum strips the hydrogen sulfide from the condensate, eliminating the need for further chemical treatment of the condensate to prevent air pollution. Hydrogen sulfide partitioning performance is further improved by converting the hydrogen sulfide in the vent gas to sulfur dioxide before contacting it with the condensate.
摘要:
Geothermal brine always contains some carbon dioxide in solution. Separating steam from geothermal brine removes the carbon dioxide, sharply increasing the pH of the brine and causing precipitation of pH sensitive minerals, including calcium carbonate, magnesium silicate and other metal silicates, clays, and metal sulfides. The binary heat exchanger in a steam-binary hybrid geothermal power plant is especially sensitive to scale deposition from flashed geothermal brine, and application of expensive scale inhibitors is required.Deposition of scale in the binary heat exchanger can be controlled by separating a small amount of gas-rich vapor from the brine before the main stage of steam separation, and combining this gas rich vapor with the flashed brine before in enters the binary heat exchanger. The carbon dioxide thus added to the brine will decrease pH, decreasing or completely blocking precipitation and deposition of pH sensitive minerals as scale.
摘要:
A large surface area electrode well-suited to electrochemical applications is produced by winding many turns of a metallic fiber tow on to a sheet metal rectangle. In the preferred embodiment, an anode that can be used to purify water by electrochemical production of hydroxyl free radical is made by winding titanium fiber tow on to a rectangular substrate made of titanium sheet, and applying a suitable multilayered electrocatalytic coating. Made of other metals, an electrode of this description can also serve as the cathode of an electrochemical cell, or as a battery plaque.
摘要:
This invention provides an electrochemical water treatment device for producing hydroxyl free radicals and decomposing by oxidation chemical substances dissolved in water. It utilizes a novel electrode which is capable of operation at sufficiently positive anodic potential to produce hydroxyl radicals.
摘要:
Hydrogen chloride in superheated steam is neutralized by contacting the steam with a solution containing potassium carbonate. A solution of potassium carbonate will remain liquid when contacted by steam superheated by as much as 40° C. and, unlike sodium carbonate, the degree of superheat of a saturated solution of potassium carbonate increases with temperature.Injection of potassium carbonate solution downhole in a dry steam geothermal well to protect the well casing from corrosion is especially beneficial, because only a small amount of carrier water needs to be injected together with the potassium carbonate, whereby the steam remains superheated and the possibility of localized corrosion is avoided.Other highly soluble potassium salts or salt inhibitors can be added to prevent precipitation of solid potassium chloride which may occur under certain conditions, or a small amount of additional water can be added to keep the potassium chloride in solution while allowing the steam to remain superheated.
摘要:
An electrode having a valve metal substrate and an electrocatalytic surface composition comprising titanium dioxide doped with bismuth is provided, and an electrolytic water purification process utilizing this electrode, wherein organic substances dissolved or dispersed in water are oxidized and degraded in a nonselective manner with good current efficiency.