The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

Frederick L. Shope - One of the best experts on this subject based on the ideXlab platform.

  • Transient Start-up Simulations for a Semiconductor Heater for a Mach 7 True Temperature Wind Tunnel
    43rd AIAA Aerospace Sciences Meeting and Exhibit, 2005
    Co-Authors: Frederick L. Shope, Arnold Afb
    Abstract:

    At the Arnold Engineering Development Center (AEDC), Arnold AFB, Tennessee, a project is under way to develop a continuous Mach 7 true-temperature wind tunnel test capability. The enabling technology for this capability is a new Electric Resistance Heater based on the semiconductor material yttria-stabilized zirconia (YsZ), which retains structural integrity at temperatures beyond 2400 K. This paper analyzes the unsteady aeroElectrical starting process of the heating elements to assess Heater feasibility to identify likely starting procedures. An unsteady axisymmetric heat conduction program was modified to model internal Electrical resistive heat generation by a semiconductor; the program then was used to compute transient element startup simulations.

  • Heat-Transfer Analysis of a Semiconductor Electric Heater for a Continuous Mach 7 True-Temperature Wind Tunnel *
    24th AIAA Aerodynamic Measurement Technology and Ground Testing Conference, 2004
    Co-Authors: Frederick L. Shope
    Abstract:

    At the Air Force Arnold Engineering Development Center, a project is under way to develop a continuous Mach 7 true-temperature wind tunnel test capability. The enabling technology for this capability is a new Electric Resistance Heater based on the semiconductor material Yttria-stabilized Zirconia (YsZ), which retains structural integrity at temperatures beyond 2400 K. This paper presents an engineering mathematical model for the envisioned Heater. The model is used to accomplish a conceptual design and suggests that a Heater design of acceptable YsZ cost (mass) and total pressure loss is feasible.

Carolina Carmo - One of the best experts on this subject based on the ideXlab platform.

  • thermal battery with co2 compression heat pump techno economic optimization of a high efficiency smart grid option for buildings
    Energy and Buildings, 2012
    Co-Authors: Morten Boje Blarke, Kazuaki Yazawa, Ali Shakouri, Carolina Carmo
    Abstract:

    Abstract Increasing penetration levels of wind and solar power in the energy system call for the development of Smart Grid enabling technologies. As an alternative to expensive electro-chemical and mechanical storage options, the thermal energy demand in buildings offers a cost-effective option for intermittency-friendly Electricity consumption patterns. Combining hot and cold thermal storages with new high-pressure compressor technology that allows for flexible and simultaneous production of useful heat and cooling, the paper introduces and investigates the high-efficiency thermal battery (TB) concept. In a proof-of-concept case study, the TB replaces an existing Electric Resistance Heater used for hot water production and an Electric compressor used for air refrigeration in a central air conditioning system. A mathematical model for least-cost unit dispatch is developed. Heat pump cycle components and thermal storages are designed and optimized. A general methodology is applied that allows for comparing the obtained results with other Smart Grid enabling options. It is found that the TB concept leads to improvements in the intermittency-friendliness of operation Rc (improves from −0.11 to 0.46), lower CO2 emissions (reduced to zero), and lower operational costs (reduced by 72%). The results indicate that TB may be the most cost-effective Smart Grid enabling option for supporting higher penetration levels of intermittent renewables in the energy system.

R. R. Raine - One of the best experts on this subject based on the ideXlab platform.

  • An integrated domestic refrigerator and hot water system
    International Journal of Energy Research, 1998
    Co-Authors: J. M. O'brien, Pradeep Bansal, R. R. Raine
    Abstract:

    This paper presents a new design of a prototype refrigeration-cum-hot water heating system for domestic use. The system uses the heat energy rejected from the compressor and condenser of a vapour-compression refrigerator by storing it in a heat sink. This energy is then transferred to mains water entering the hot water cylinder, where the water temperature is boosted by an Electric Resistance Heater to a preset temperature for domestic usage. A prototype system of such a configuration was assembled as an integrated unit with the refrigerator adjacent to the water tank. The system is called the Home Energy Centre (HEC). Power consumption and temperature distribution were measured for standing and draw off tests using the unit as a conventional hot water cylinder, refrigerator or as the combined system. A new parameter, ϕ, is defined to compare the system performance as the HEC prototype against its performance when working only as a refrigerator or a water Heater. The system performed better as the prototype than it did as a hot water Heater, but needs to be improved further to fully explore its expected potential. © 1998 John Wiley & Sons, Ltd.

Changduk Jeon - One of the best experts on this subject based on the ideXlab platform.

  • frost retardation of an air source heat pump by the hot gas bypass method
    International Journal of Refrigeration-revue Internationale Du Froid, 2008
    Co-Authors: Ju-suk Byun, Changduk Jeon
    Abstract:

    This study is concerned with a hot gas (refrigerant) bypass method to retard the formation and propagation of frost in an air-source heat pump. The feasibility of the hot gas bypass method was investigated experimentally and the method's performance is compared with that of a normal, 1.12 kW capacity air-source heat pump system with no defrost equipment such as an Electric Resistance Heater. Results indicate that the hot gas bypass method is useful for retarding the formation and growth of frost at the outdoor coil. The best performance is shown under a bypass refrigerant flow rate of 0.2 kg/min (20% of the whole system refrigerant flow rate). During 210 min of heat pump operation, the hot gas bypass method improved COP and heating capacity at an average of 8.5% and 5.7%, respectively, relative to the normal system.

Arnold Afb - One of the best experts on this subject based on the ideXlab platform.

  • Transient Start-up Simulations for a Semiconductor Heater for a Mach 7 True Temperature Wind Tunnel
    43rd AIAA Aerospace Sciences Meeting and Exhibit, 2005
    Co-Authors: Frederick L. Shope, Arnold Afb
    Abstract:

    At the Arnold Engineering Development Center (AEDC), Arnold AFB, Tennessee, a project is under way to develop a continuous Mach 7 true-temperature wind tunnel test capability. The enabling technology for this capability is a new Electric Resistance Heater based on the semiconductor material yttria-stabilized zirconia (YsZ), which retains structural integrity at temperatures beyond 2400 K. This paper analyzes the unsteady aeroElectrical starting process of the heating elements to assess Heater feasibility to identify likely starting procedures. An unsteady axisymmetric heat conduction program was modified to model internal Electrical resistive heat generation by a semiconductor; the program then was used to compute transient element startup simulations.