US 7,118,820 B2Granted

Method and apparatus for humidification control of an energy recovery device in a fuel cell power plant

AssigneeUTC Fuel Cells, LLC

InventorsBenjamin Charles Nuttall, Bryan F. Dufner, Albert P. Grasso

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Abstract

An arrangement is provided in a fuel cell power plant (10) for dispensing (58 74, 60, 64) a liquid medium, such as water (66), into a process oxidant (air) stream (53) that flows through one gas channel (42) in an energy recovery device (ERD) (32). An exhaust gas stream (48) containing heat and moisture from the fuel cell (12) flows through another channel (44) in the ERD. An enthalpy exchange barrier (46) separates the one and the other gas channels, but allows mass and/or heat transfer therebetween. The water is injected into the air stream (53) in a controlled (70, 74) amount, and perhaps temperature (78), in response to sensed parameters (80, 84, 90) of the power plant, including the process air stream, to adjust one or more conditions in the power plant. Controlling ERD dryness, providing a defrost capability for the ERD, and/or preventing excessive water accumulation in the system are several of the conditions controlled.

Claims16

Dependent claims

A fuel cell power plant (10) for generating electrical energy from a process oxidant stream (53, 42, 28) and a reducing fluid stream (26), the plant comprising:

a) at least one fuel cell (12) for producing the electrical energy from the process oxidant stream (53, 28) and the reducing fluid stream (26), and providing a fuel cell exhaust stream (48) containing moisture and sensible heat;
b) an energy recovery device (32) having first and second gas flow channels (44, 42) separated by a respective enthalpy exchange barrier (46), the fuel cell exhaust stream (48) connected to pass through the first gas flow channel (44) and a source of process oxidant (30) for the process oxidant stream (53) connected to pass through the second gas flow channel (42), thereby to allow mass and heat transfer between the gases in the first and second gas flow channels via the enthalpy exchange barrier;
c) a supply of liquid medium (66);
and
d) means (58, 60) for injecting the liquid medium (66, 64) substantially directly into the process oxidant stream (53) preparatory to the process oxidant passing through the energy recovery device second gas flow channel (42) for regulating the transfer of mass and heat between the fuel cell exhaust stream (48) and the process oxidant stream (53, 42).

2 more elements

In a fuel cell power plant (10) for generating electrical energy from a process oxidant stream (53, 42, 28) and a reducing fluid stream (26), the plant comprising a fuel cell (12) for producing the electrical energy from the process oxidant stream (53, 28) and the reducing fluid stream (26), and providing a fuel cell exhaust stream (48) containing moisture and sensible heat;

and an energy recovery device (32) having first and second gas flow channels (44, 42) separated by a respective enthalpy exchange barrier (46), the fuel cell exhaust stream (48) connected to pass through the first gas flow channel (44) and a source of process oxidant (30) for the process oxidant stream (53) connected to pass through the second gas flow channel (42), thereby to allow mass and heat transfer between the gases in the first and second gas flow channels via the enthalpy exchange barrier, the method comprising:
dispensing water (66, 70, 74, 60, 64) substantially directly into the process oxidant stream (53) preparatory to the process oxidant passing through the energy recovery device second gas flow channel (42) for regulating the transfer of mass and heat between the fuel cell exhaust stream (48) and the process oxidant stream (53, 42).

Dependencies are inferred from the claim text.