| OCR Text |
Show Diesel Burner Development for 500-Watt Portable Thermophotovoltaic Generator Authors: Mark V. Scotto McDermott Technology Inc., Alliance, Ohio 44601 ABSTRACT McDermott Technology, Inc. (MTI) and JX Crystals (JXC) are developing a portable thermophotovoltaic (TPV) electric generator under a Defense Advanced Research Projects Agency ( D A R P A ) contract. The contract is managed by the U.S. Army's Communication and Electronic C o m m a n d ( C E C O M ) due to its interest in the device for field applications. The generator is designed to burn diesel fuel (DF-2) at an overall efficiency of 8 % - 1 0 % and net output of 500 watts D C power. M T I is developing the burner / emitter / recuperator (BER), which converts chemical energy in the fuel to a uniform radiant heat flux directed toward the photovoltaic cells. A thermally integrated, high-temperature recuperator was used to increase fuel efficiency by preheating the combustion air. The power converter assembly (PCA) developed by J X C converts the radiant flux that emanates from the emitter to electrical power using an array of photovoltaic cells. This paper describes the burner development work at MTI. A burner system was designed and fabricated to efficiently elevate the emitter to a uniform temperature exceeding 2400 °F, the required temperature to efficiently convert the radiant flux to electricity. The burner system generated a stable feed of vaporized fuel using a flow orifice. A short compact flame was produced with rapid heat release near the burner to achieve high energy efficiency and low emission of C O and soo'. Emitter temperature data for integrated systems under different operational conditions aiv presented. Introduction M T I teamed with J X C to develop a thermophotovoltaic (TPV) generator that uses diesel (DF-2) fuel to produce 500 watts of electricity at a net energy efficiency of 8 % to 10%. The generator was designed to be light (~ 15 lbs) and have a low thermal and acoustic signature. The team was successful in developing a working benchtop B E R and PCA. The two devices were combined at the M T I Thermophotovoltaic Laboratory to make a one-of-a-kind laboratory test station with unique measurement capabilities. Phase I ended with a demonstration test that showed the laboratory prototype to be an effective tool for advancing the state of the art in T P V electric power generation. The development of the burner assembly that was integrated with M T F s cylindrical B E R subsystem design is described. The basic elements of a TPV electric generator are shown in Figure 1. TPV systems work by converting radiant energy generated by an incandescent emitter into D C electricity. As shown in Figure 1, a burner is used to heat a ceramic emitter. The emitter is heated and radiates energy to photovoltaic (PV) cells that convert a portion of the radiant energy into electrical energy. The wavelengths of light must exceed the cell's bandgap energy to be converted into 1 |
