SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  OSD07-ES1 (OSD)
Title:  Portable Cogeneration of Power and Cooling
Research & Technical Areas:  Ground/Sea Vehicles

Acquisition Program:  DDR&E EPTI
  Objective:  Develop a portable, ultraquiet power generation system capable of simultaneously providing 5 kW of electric power and 10 kW of cooling power.
  Description:  The escalating use of electronic equipment on the battlefield requires increasing amounts of field deployable electric power. These electronic systems are often housed in sealed enclosures or shelters to provide protection against environmental hazards. When operating in warm environments, these enclosures require additional air conditioning to maintain ambient air temperatures below that required for reliable operation of electronics. One solution is to incorporate an external air conditioning system to provide the necessary cooling while drawing power from the same electric source. If power is provided from a diesel generator, it may be more efficient to directly convert heat from fuel burning to cooling power through an absorption chiller, for example, while simultaneous providing the power for the electronic equipment. At the same time, quiet operation is required in many tactical situations. Technologies which use external combustion, such as Stirling, thermoacoustic, and thermophotovoltaics, perform quieter and often with less exhaust emissions in comparison with internal combustion engines. This topic seeks innovative approaches to applying such technologies to the efficient cogeneration of power and cooling.

  PHASE I: Evaluate technologies for providing quiet cogeneration of power and cooling in a battlefield environment. Design a prototype system capable of providing 5 kW (continuous) of 120 VAC, 60 hz electric power and 10 kW of cooling power. The generator should be able to operate directly on JP-8 fuel with no additional logistic load, weigh approximately 500 pounds (excluding fuel), and have an acoustic signature of less than 40 dB at 5 meters. The unit should be able to operate at ambient temperatures from -25 to 140 deg F.
  PHASE II: Demonstrate a prototype system using the concept developed in Phase I. This unit must be portable, maintainable, and reliable. Evaluate the efficiency of the prototype under various electrical and cooling loads and temperatures.

  PHASE III: Develop final design and commercialization plans using the knowledge gained during Phases I and II.

  PRIVATE SECTOR COMMERCIAL POTENTIAL: Cogeneration of electrical power and air conditioning has application in both residential and commercial settings. High efficiency, quiet cogeneration units in this power range have potential markets in commercial trucking and recreational vehicles.

  References:  1. http://www.marcorsyscom.usmc.mil/sites/PMEPS/MEP.asp 2. S. Backhaus, E. Tward, and M. Petach, “Traveling-wave thermoacoustic electric generator,” Appl. Phys. Lett. 85, 1085 (2004). 3. X.Q. Kong, R. Z. Wang, and X.H. Huang, “Energy efficiency and economic feasibility of CCHP driven by stirling engine,” Energy Convers. Manage. 45, 1433 (2004).

Keywords:  power generation, cogeneration, therrmoacoustic refrigeration, Stirling engine

Additional Information, Corrections, References, etc:
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Questions and Answers:
Q: What is the enclosure temperature?
A: The nominal enclosure temperature is not specified. However, cooling temperature should be at least 25 F below ambient.
Q: 1. How is the cooling to be transmitted to the enclosed men and equipment? By cool air or by chilled liquid?
2. On a 140F day, what is the highest exit temperature from the enclosed space allowed for the cooling air or liquid?
A: 1. Air.
2. The exact temperature is not specified. However, cooling temperature should be at least 25 F below ambient.
Q: What is the enclosure temperature?
A: The nominal enclosure temperature is not specified. However, cooling temperature should be at least 25 F below ambient.
Q: 1. How is the cooling to be transmitted to the enclosed men and equipment? By cool air or by chilled liquid?
2. On a 140F day, what is the highest exit temperature from the enclosed space allowed for the cooling air or liquid?
A: 1. Air.
2. The exact temperature is not specified. However, cooling temperature should be at least 25 F below ambient.

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