Patent Application
20100024424
Exemplary embodiments of the present invention relate to the art of combined cycle power plants and, more particularly, to a condenser for a steam turbine portion of a combined cycle power plant.
Conventional combined cycle power plants employ a gas turbine system operatively coupled to a steam turbine system. The gas turbine system includes a compressor coupled to a gas turbine. The steam turbine system includes a high pressure turbine (HP) portion operatively coupled to an intermediate pressure (IP) turbine portion that, in turn is coupled to low pressure (LP) turbine. The LP turbine is employed to drive, for example, a generator. In a typical combined cycle power plant, exhaust gas from the steam turbine, typically in the form of steam, is passed to a cooling system, onto a bottoming cycle and back to a heat recovery steam generator to be reheated and passed back to the steam turbine. A large amount of latent heat must be removed from the exhaust gas in to condense the steam back to water.
Conventional cooling systems employ water to remove the latent heat from the exhaust/steam through a water-to-steam heat exchanger. Once condensed, a large cooling tower or a large water reservoir is required to cool/store the water. In places that lack water, a steam-to-air heat exchanger is used. Steam-to-air heat exchangers are less efficient that water-to-steam heat exchangers and require a large footprint.
In accordance with one exemplary embodiment of the invention, a combined cycle power plant includes a steam turbine section having an inlet section and an outlet section. The steam turbine section passes steam from the inlet section toward the outlet section. The combined cycle power plant also includes a condenser fluidly connected to the outlet section of the steam turbine section. The condenser includes a plurality of heat pipes configured to extract latent heat from steam passing from the steam turbine section to form condensed water.
In accordance with another exemplary embodiment of the invention, a method of extracting latent heat from a steam flow passing from a steam turbine section includes passing the steam flow from the steam turbine section, guiding the steam flow to a condenser having a plurality of heat pipes, and passing the steam flow over the plurality of heat pipes. The heat pipes absorbing latent heat from the steam flow to form condensed water.
In accordance with yet another exemplary embodiment of the invention, a condenser fluidly connected to a steam turbine section includes a plurality of heat pipes configured to extract latent heat from steam passing from the steam turbine section to form condensed water.
With initial reference to
As further shown in
Reference will now be made to
Each of the plurality of heat pipes 146 includes an external surface (not separately labeled), a first end portion 160 that extends through interior chamber 128, leading to a second end portion 161, arranged outside of the vessel, through an intermediate or heat exchange zone 163. Heat exchange zone 163 actually includes a first heat exchange portion 167, e.g., the portion of each of the plurality of heat pipes 146 located within interior chamber 128, and a second heat exchange portion 168, e.g., the portion of each of the plurality of heat pipes 146 located outside of interior chamber 128. In the embodiment show, second heat exchange portion 168 is arranged in a heat exchanger 170 positioned adjacent a pair of fans 174 and 175. With this arrangement, latent heat entrained in the steam passing from LP turbine section 64 flows over the external surface of heat pipes 146 and is absorbed by first heat exchange portion 163 to form condensed water. The heat is rapidly conducted though heat exchange zone 163 to second heat exchange portion 168. A convective airflow generated by fans 174 and 175 passes across the external surface of second heat exchange portion 168 to remove the heat. The water is passed to HRSG 90 and reheated by exhausts gases 33 to form additional steam that is passed back to various portions of steam turbomachine system 6.
At this point it should be appreciated that a condenser constructed in accordance with exemplary embodiments of the invention would be simple to build and be easy to maintain and provide enhanced heat removal efficiency. Moreover, the condenser in accordance with the exemplary embodiment would not require water as a coolant or any associated water handling/storage equipment. Finally, the condenser in accordance with exemplary embodiments of the invention can be constructed on a relatively small footprint.
In general, this written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of exemplary embodiments of the present invention if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
