D. Yogi Goswami

Handbook of energy efficiency and renewable energy

Global energy system / D. Yogi Goswami, Frank Kreith -- Energy policy -- Economics methods / Rosalie Ruegg, Walter Short -- Environmental impacts and costs of energy / Ari Rabl, Joseph V. Spadaro -- Distributed generation and demand-side management -- Generation technologies through the year 2025 -- Outlook for U.S. energy consumption and prices in the midterm / Andy S. Kydes -- Transportation systems / Beth Isler -- Infrastructure risk analysis and security -- Electrical energy management in buildings / Craig B. Smith, Kelly E. Parmenter -- Heating, ventilating, and air conditioning control systems / Jan F. Kreider, David E. Claridge, Charles H. Culp -- Energy efficient technologies -- Compact heat exchangers : recuperators and regenerators / Ramesh K. Shah -- Industrial energy efficiency and energy management / Craig B. Smith, Barney L. Capehart, Wesley M. Rohrer Jr. -- Process energy efficiency : pinch technology -- Energy audits for buildings / Moncef Krarti -- Cogeneration / W. Dan Turner -- Energy storage, transmission, and distribution -- Availability of renewable resources -- Solar thermal energy conversion -- Concentrating solar thermal power / Manuel Romero-Alvarez, Eduardo Zarza -- Wind energy conversion / Dale E. Berg -- Photovoltaics fundamentals, technology, and application -- Waste-to-energy combustion / Charles O. Velzy, Leonard M. Grillo -- Biomass conversion processes for energy recovery -- Geothermal power generation / Kevin Kitz -- Hydrogen energy technologies / S.A. Sherif, F. Barbir, T.N. Veziroglu, M. Mahishi, S.S. Srinivasan -- Fuel cells / Xianguo Li -- Appendices / Nitin Goel.

Synthesis, characterization, and applications of ZnO nanowires

ZnO nanowires (or nanorods) have been widely studied due to their unique material properties and remarkable performance in electronics, optics, and photonics. Recently, photocatalytic applications of ZnO nanowires are of increased interest in environmental protection applications. This paper presents a review of the current research of ZnO nanowires (or nanorods) with special focus on photocatalysis. We have reviewed the semiconducting photocatalysts and discussed a variety of synthesis methods of ZnO nanowires and their corresponding effectiveness in photocatalysis. We have also presented the characterization of ZnO nanowires from the literature and from our own measurements. Finally, a wide range of uses of ZnO nanowires in various applications is highlighted in this paper.

A combined power/cooling cycle

A combined thermal power and cooling cycle is proposed. The proposed cycle combines a Rankine cycle and an absorption refrigeration cycle. It can provide power output as well as refrigeration with power generation as a primary goal. The new cycle uses very high concentration ammonia vapor in the turbine which can be expanded to a very low temperature in the turbine without condensation. This cycle uses an absorption condensation process instead of the conventional condensation process. A parametric analysis of the proposed cycle is presented in this paper.

Thermodynamic properties of ammonia-water mixtures for power-cycle applications

Ammonia–water mixtures have been used as working fluids in absorption–refrigeration cycles for several decades. Their use as multi-component working fluids for power cycles has been investigated recently. The thermodynamic properties required are known or may be calculated at elevated temperatures and pressures. We present a new method for these computations using Gibbs free energies and empirical equations for bubble and dew point temperature to calculate phase equilibria. Comparisons of calculated and experimental data show excellent agreement.

Solar Thermal Power Technology: Present Status and Ideas for the Future

This article reviews some recent developments in thermodynamic cycles as well as new and innovative thermal power cycles applicable to solar thermal power

Nanomaterials for Hydrogen Storage Applications: A Review

Nanomaterials have attracted great interest in recent years because of the unusual mechanical, electrical, electronic, optical, magnetic and surface properties. The high surface/volume ratio of these materials has significant implications with respect to energy storage. Both the high surface area and the opportunity for nanomaterial consolidation are key attributes of this new class of materials for hydrogen storage devices. Nanostructured systems including carbon nanotubes, nano-magnesium based hydrides, complex hydride/carbon nanocomposites, boron nitride nanotubes, nanotubes, alanates, polymer nanocomposites, and metal organic frameworks are considered to be potential candidates for storing large quantities of hydrogen. Recent investigations have shown that nanoscale materials may offer advantages if certain physical and chemical effects related to the nanoscale can be used efficiently. The present review focuses the application of nanostructured materials for storing atomic or molecular hydrogen. The synergistic effects of nanocrystalinity and nanocatalyst doping on the metal or complex hydrides for improving the thermodynamics and hydrogen reaction kinetics are discussed. In addition, various carbonaceous nanomaterials and novel sorbent systems (e.g. carbon nanotubes, fullerenes, nanofibers, polyaniline nanospheres and metal organic frameworks etc.) and their hydrogen storage characteristics are outlined.

Analysis of an innovative water desalination system using low-grade solar heat☆

Abstract This paper presents a theoretical analysis and preliminary experimental results for an innovative water desalination system using low-grade solar heat. The system utilizes natural means (gravity and atmospheric pressure) to create a vacuum under which water can be rapidly evaporated at much lower temperatures and with less energy than conventional techniques. The system consists of an evaporator connected to a condenser. The vapor produced in the evaporator is driven to the condenser where it condenses and is collected as a product. The effect of various operating conditions, namely, withdrawal rate, depth of water body in the evaporator, temperature of the heat source, and condenser temperature, on the system performance were studied. Numerical simulations and preliminary experimental results show that the performance of this system is superior to a flat basin solar still, and the output may be twice that of a flat-basin solar still for the same input. Vacuum equivalent to 4 kPa (abs) or less can be created depending on the ambient temperature at which condensation takes place.

Analysis of a new thermodynamic cycle for combined power and cooling using low and mid temperature solar collectors

A combined thermal power and cooling cycle is proposed which combines the Rankine and absorption refrigeration cycles. It can provide power output as well as refrigeration with power generation as a primary goal. Ammonia-water mixture is used as a working fluid. The boiling temperature of the ammonia-water mixture increases as the boiling process proceeds until all liquid is vaporized, so that a better thermal match is obtained in the boiler. The proposed cycle takes advantage of the low boiling temperature of ammonia vapor so that it can be expanded to a low temperature while it is still in a vapor state or a high quality two phase state. This cycle is ideally suited for solar thermal power using low cost concentrating collectors, with the potential to reduce the capital cost of a solar thermal power plant. The cycle can also be used as a bottoming cycle for any thermal power plant. This paper presents a parametric analysis of the proposed cycle.

Effectiveness of Heat and Mass Transfer Processes in a Packed Bed Liquid Desiccant Dehumidifier/Regenerator

Seasonal performance simulations of liquid desiccant cooling systems provide valuable information for developing cost-competitive and energy efficient alternatives to conventional air conditioning techniques. To ensure reliable simulation results, component models must be based on and verified by experimental data. This paper presents closed-form performance correlations for the effectiveness of heat and mass transfer processes in a packed bed dehumidifier/regenerator. The physical phenomena relevant to the heat and mass transfer in these devices has been used to develop a novel set of correlations based on the relevant nondimensional parameters. A large body of previously reported experimental data, including results recently obtained by the present authors, was used in deriving the correlations. The key improvements offered by these newly developed correlations include the applicability for both dehumidification and regeneration, inclusion of proper nondimensional parameters such as wettability, and extension in range of validity. The number of different studies used makes these correlations valid for broad ranges of conditions encountered in packed bed liquid desiccant dehumidifiers and regenerators.

Optimization of a novel combined power/refrigeration thermodynamic cycle

A novel combined power/refrigeration thermodynamic cycle is optimized for thermal performance in this paper. The cycle uses ammonia-water binary mixture as a working fluid and can be driven by various heat sources, such as solar, geothermal and low temperature waste heat. It could produce power as well as refrigeration with power output as a primary goal. The optimization program, which is based on the Generalized Reduced Gradient (GRG) algorithm, can be used to optimize for different objective functions. Examples that maximize second law efficiency, work output and refrigeration output are presented, showing the cycle may be optimized for any desired performance parameter. In addition, cycle performance over a range of ambient temperatures was investigated. It was found that for a source temperature of 360K, which is in the range of flat plate solar collectors, both power and refrigeration outputs are achieved under optimum conditions. All performance parameters, including first and second law efficiencies, power and refrigeration output decrease as the ambient temperature goes up. On the other hand, for a source of 440K, optimum conditions do not provide any refrigeration. However, refrigeration can be obtained even for this temperature under non-optimum performance conditions.Copyright