Method and apparatus for commissioning power plants
AssigneeBoyle Energy Services & Technology, Inc.
InventorChristopher J. Bloch
Life of this patent
Estimating the term…
Abstract
An apparatus and method for commissioning steam turbine generator power plants to advance the cleanliness of the complete steam cycle by the conditioned discharge of steam to the plant surface condenser.
Claims18
A process for steam flushing, as part of commissioning a steam driven turbine plant with one or more steam circuits, each one or more steam circuits comprising:
- a steam heating source, a turbine, a condenser, and conduit means between the condenser and an exhaust for the turbine, wherein particulate and non-particulate contamination are removed from the one or more steam circuits in coordination with exhaust of flush steam to the condenser of the one or more steam circuits, said process comprising the steps of:
- (a) removing particulate and non-particulate contamination from the flush steam prior to the entry of said flush steam to the condenser by introducing steam circuit condensate into the flush steam at one or more injection points to generate a mixed phase annular mist of steam and liquid condensate droplets to induce turbulence therein to entrain contaminants and then separating the droplets and entrained contaminants from the steam circuit via a bypass, prior to admission of said flush steam to the plant condenser;
- (b) testing the flush steam for contaminants prior to the entry of said flush steam to the condenser,
- (c) admitting flush steam to the condenser for the bulk of the commissioning process, having fully evaporated the previously injected condensate droplets before admission to the condenser, then rapidly terminating the entry of flush steam to the condenser should there be the potential for damage to the condenser by the entry of said flush steam to the condenser, and
- (d) adding volatile chemistry component to said condensate used to generate the flush steam to effect simultaneous removal of particulate and non-particulate contamination from the steam circuits and capturing the flush steam and the added components for recycling use in the commissioning.
An improved process for commissioning equipment comprising one or more steam circuits, each steam circuit including closed cycle components of a steam source which feed steam from the steam source via steam piping to a turbine, exhaust steam from the turbine via steam piping to a condenser and return steam from the condenser via steam piping to the steam source, the improved process comprising the steps of:
- (a) performing a bypass operation by flushing all steam flow exposed components of the steam circuit with a cleansing steam flow while bypassing the condenser, feeding the cleansing steam flow to the condenser while continuing the flushing of the steam circuit for the bulk of the commissioning process once the level of contamination present in the cleansing steam is determined to be sufficiently low,
- (b) providing substantially full base load operation of the steam circuit while feeding the cleansing steam flow to the condenser to provide elevated steam temperature and elevated steam flow rate, and recycling condensate from the condenser back into the steam circuit by injecting the recycled condensate into the steam piping at spaced locations along the steam circuit piping between the turbine and the condenser to thereby create water droplets in the cleansing steam flow to provide a two phase annular mist to reduce cleansing steam temperature by evaporation of water droplets therein and dislodge solid particle contamination from the steam circuit piping surface by impinging the steam circuit piping surface with the water droplets present within the cleansing steam;
- and
- (c) adding pH adjusting chemicals to establish steam pH above 10.0 to enhance the solubility of silica from the steam circuit surfaces into the cleansing steam.
A process for commissioning a combined cycle as turbine/steam turbine plant with a closed loop combustion gas turbine running a primary gas turbine cycle, the primary gas turbine cycle comprising a heat recovery portion for heating, evaporating and superheating steam present in steam piping running through the heat recovery portion, the heat recovery portion serving as a steam generating source for operating the steam turbine, the plant further comprising feeding exhaust steam from the steam turbine via a condenser to the heat recovery portion, the process including the steps of:
- (a) running the heat recovery portion and/or a supplementary boiler to provide steam that runs through the steam piping of the heat recovery portion of the gas turbine cycle, but diverting the steam and preventing admission of the steam to the steam turbine,
- (b) temporarily conditioning the steam by injecting condensate from the condenser and/or make up condensate from a supplemental source, to the piping of the heat recovery portion so as to increase steam turbulence, reduce steam temperature, wash the steam by entraining particulate and non-particulate contaminants, and produce a wash condensate which contains the entrained particulate and non-particulate contaminants,
- (c) bypassing the condenser while conditioning the steam, until a target level of cleanliness is achieved, and then admitting the cleaned steam to the condenser,
- (d) coalescing the steam, cyclonically separating the steam from the wash condensate laden with contaminants, and venting the steam to the atmosphere using an exhaust device with means for mitigating noise,
- (e) routing the cleaned steam to the condenser and diffusing and screening the cleaned steam entry to the condenser while pulling vacuum on the condenser to reduce back pressure on the cleaned steam entering the condenser thus increasing velocity of the steam, and
- (f) removing liquid condensate from the condenser and replacing it with make up condensate to feed the gas cycle heat recovery portion.
Dependencies are inferred from the claim text.