Project Title:

Reliable Capillary Pumping for High Efficiency AMTEC Cells

94-1	10.02	3800		

Reliable Capillary Pumping for High Efficiency AMTEC Cells

Abstract:

We propose to develop an innovative capillary pumping system for 
AMTEC cells that will enable reliable, long-term operation with 
conversion efficiencies greater than 20%. The capillary pumping 
system enables high efficiencies because the cell's evaporator can 
run at temperatures exceeding 1100 K. Long-term stability at high 
temperature is accomplished with a micromachined capillary 
structure that is stable regardless of the evaporator temperature. 
AMTEC power conversion at 20% efficiency dramatically reduces the 
mass of power conversion systems for spacecraft (by 50% for systems 
using a Solar Heat Source). High conversion efficiency reduces the 
cost of commercial AMTEC power systems because less input thermal 
energy is required and fewer AMTEC cells are necessary. Reliability 
improves because the capillary pumping system eliminates active 
electromagnetic pumps. In Phase I we will prove the feasibility of 
the proposed system by (1) proof-of-concept tests which demonstrate 
the fundamental principles of operation, (2) fabrication 
experiments that demonstrate micromachining of prototypical 
materials, (3) producing a conceptual design of an AMTEC cell that 
incorporates the proposed system, and (4) performing analysis of 
cell behavior to demonstrate the expected cell efficiency greater 
than 20%.

The proposed capillary pumping system enables high power conversion 
efficiency that can cut the weight of spacecraft power systems by 
half. AMTEC cells have numerous commercial applications as an 
efficient, lightweight, omni-fueled power generator: range 
extension for electric vehicles, cogeneration and backup power 
using heat from residential furnaces, remote power generation for 
communications, environmental monitoring, cathodic protection of 
pipelines, and electric power generation for recreational vehicles, 
camping equipment, and small boats.

Key Words

Creare Incorporated
Etna Road, P.O. Box 71
Hanover, NH 03755