Pressurized high temperature fuel cell power plant with bottoming cycle
AssigneeUnited Technologies Corporation
InventorLeslie L. Van Dine
Life of this patent
Estimating the term…
Abstract
A power plant for the generation of electricity utilizes high temperature fuel cells, such as molten carbonate fuel cells, as its main power supply. Part of the oxidant exhaust stream from the fuel cell is recycled through the fuel cell. Waste energy from the fuel cell in the form of exhaust gases, such as part of the oxidant exhaust, drives a turbocharger for compressing the oxidant used in the fuel cell. In a preferred embodiment the oxidant exhaust also is the source of energy for powering a bottoming cycle, such as a steam driven turbogenerator. Power plant efficiency is improved by making maximum use of the energy and heat generated within the system.
Claims30
A fuel cell power plant comprising:
- a plurality of molten carbonate fuel cells connected electrically in series, each cell including means defining a fuel space and means defining an oxidant space;
- turbocharger means including first turbine means operably connected to a compressor for driving said compressor;
- second turbine means operably connected to an electric generator;
- burner means disposed downstream of said fuel space for burning fuel space effluent;
- means for delivering pressurized, processed fuel into said fuel space including fuel processing apparatus disposed upstream of said fuel space;
- means for delivering raw fuel into said fuel processing apparatus;
- means for delivering pressurized oxidant from said turbocharger means and effluent from said fuel space into said burner means;
- means for delivering effluent from said burner means into said oxidant space;
- means for dividing the oxidant space effluent into a first portion and a second portion and for recycling said first portion through said oxidant space and for delivering said second portion into said first turbine means for driving said compressor;
- and
- means for transferring heat energy from the oxidant space effluent to said second turbine means to drive said electric generator, including means for transferring heat energy from the first turbine means exhaust gases to said second turbine means.
A fuel cell power plant comprising:
- a plurality of molten carbonate fuel cells connected electrically in series, each cell including means defining a fuel space and means defining an oxidant space;
- turbocharger means including a turbine operably connected to a compressor for driving said compressor;
- an exothermic fuel processing reactor disposed upstream of said fuel space;
- burner means disposed downstream of said fuel space and upstream of said oxidant space;
- steam turbine means operably connected to an electric generator;
- means for delivering raw fuel into said reactor;
- means for delivering pressurized oxidant from said turbocharger means into said reactor;
- means for delivering pressurized, processed fuel from said reactor into said fuel space;
- means for delivering pressurized oxidant from said turbocharger means and effluent from said fuel space into said burner means;
- means for delivering effluent from said burner means into said oxidant space;
- means disposed downstream of said oxidant space for splitting said oxidant space effluent into a recycle portion and an exhaust portion;
- means for recycling the recycle portion through said oxidant space;
- means for delivering the exhaust portion into said turbocharger means;
- first heat exchanger means in heat exchange relationship with said recycle portion and with the turbocharger exhaust gases for converting water to steam and for superheating said steam;
- means for delivering said superheated steam from said first heat exchanger means into said steam turbine;
- second heat exchanger means disposed upstream of said fuel space and in heat exchange relationship with the heat generated by said reactor for superheating steam;
- and
- means for delivering the superheated steam from said second heat exchanger means into said steam turbine.
In the method of operating a fuel cell power plant, the power plant comprising a plurality of molten carbonate fuel cells connected electrically in series, each cell including means defining a fuel space and means defining an oxidant space, turbocharger means including first turbine means operably connected to a compressor, second turbine means operably connected to an electric generator, burner means, and fuel processing apparatus, the steps of:
- delivering raw fuel into the fuel processing apparatus;
- processing the raw fuel in said apparatus including producing hydrogen from the raw fuel;
- delivering the hydrogen produced into the fuel space;
- pressurizing an oxidant in the turbocharger means and delivering pressurized oxidant from the turbocharger means into the burner means;
- delivering the fuel space effluent into the burner means and burning the effluent therein;
- delivering the burner means effluent into the oxidant space;
- recycling a first portion of the oxidant space effluent through the oxidant space;
- delivering a second portion of the oxidant space effluent into said first turbine means for driving the compressor;
- and
- transferring heat energy from the oxidant space effluent to said second turbine means including the step of transferring heat energy from said first turbine means exhaust gases to said second turbine means.
In the method of operating a fuel cell power plant, the power plant comprising a plurality of molten carbonate fuel cells connected electrically in series, each cell including means defining a fuel space and means defining an oxidant space, turbocharger means including first turbine means operably connected to a compressor, second turbine means operably connected to an electric generator, burner means, and fuel processing apparatus, the steps of:
- delivering raw fuel into the fuel processing apparatus;
- processing the raw fuel including producing hydrogen from the raw fuel;
- delivering the hydrogen produced into the fuel space;
- pressurizing air in the turbocharger means and delivering the pressurized air from the turbocharger means into the oxidant space;
- delivering CO.sub.2 from the fuel space effluent into the oxidant space;
- delivering the fuel space effluent into the burner means and burning the effluent therein;
- recycling a first portion of the oxidant space effluent through the oxidant space;
- using the heat generated by the burner means to heat the gases being delivered into the oxidant space;
- delivering a second portion of the oxidant space effluent into said first turbine means for powering said first turbine means;
- and
- transferring heat energy from the oxidant space effluent to said second turbine means including the steps of transferring heat energy from said first turbine means exhaust gases to said second turbine means.
In a fuel cell power plant comprising a plurality of molten carbonate fuel cells connected electrically in series, each cell including means defining a fuel space and means defining an oxidant space, turbocharger means including first turbine means operably connected to a compressor for driving said compressor, burner means disposed downstream of said fuel space for burning fuel space effluent, means for delivering pressurized, processed fuel into said fuel space including fuel processing apparatus disposed upstream of said fuel space, means for delivering raw fuel into said fuel processing apparatus, means for delivering pressurized oxidant from said turbocharger means and effluent from said fuel space into said burner means, the improvement comprising:
- means for delivering effluent from said burner means into said oxidant space;
- and
- means for dividing the oxidant space effluent into a first portion and a second portion and for recycling said first portion through said oxidant space and for delivering said second portion into said first turbine means for driving said compressor.
In the method of operating a fuel cell power plant, the power plant comprising a plurality of molten carbonate fuel cells connected electrically in series, each cell including means defining a fuel space and means defining an oxidant space, turbocharger means including first turbine means operably connected to a compressor, second turbine means operably connected to an electric generator, burner means, and fuel processing apparatus, the steps of:
- delivering raw fuel into the fuel processing apparatus;
- processing the raw fuel in said apparatus including producing hydrogen from the raw fuel;
- delivering the hydrogen produced into the fuel space;
- pressurizing an oxidant in the turbocharger means and delivering pressurized oxidant from the turbocharger means into the burner means;
- delivering the fuel space effluent into the burner means and burning the effluent therein;
- delivering the burner means effluent into the oxidant space;
- recycling a first portion of the oxidant space effluent through the oxidant space;
- dividing the oxidant space effluent into a first portion and a second portion;
- recycling said first portion through said oxidant space;
- and
- delivering said second portion into said first turbine means for driving the compressor.
Dependencies are inferred from the claim text.