This book consists of two different research problems. In the first one, the aim is to model and simulate a solar-powered, single-effect, absorption refrigeration system using a flat-plate solar collector and LiBr-H2O mixture as the working fluid. The cooling capacity and the coefficient of performance of the system are analyzed by varying all independent parameters, namely: evaporator pressure, condenser pressure, mass flow rate, LiBr concentration, and inlet generator temperature. The cooling performance of the system is compared with conventional vapor-compression systems for different refrigerants (R-134a, R-32, and R-22). The cooling performance is also assessed for a typical year in Tampa, Florida. In the second problem, a numerical model is developed for a typical food retail store refrigeration/HVAC system to study the effects of indoor space conditions on supermarket energy consumption. Refrigerated display cases are normally rated at a store environment of 24C (75F) and a relative humidity of 55%. If the store can be maintained at lower relative humidity, significant quantities of refrigeration energy, defrost energy and anti-sweat heater energy can be saved.4803 Руб.
In this text book, mathematical formulations for the dynamics of raising sunken vessels using buoyant systems are developed in a form which is suitable for integrating control techniques to ensure both hydrodynamic and structural stability for a safe and stable salvaging operation based on both rigid body modeling and flexible body modeling concepts. Due to the coupled nature of salvage dynamics and for integrating controller techniques, the mathematical modeling is carried out as two subsystems. In the primary model, the salvage dynamics is formulated in such a way that the variation in additional buoyancy due to flow rate of filling gas inside the lift bags is the controlling force with respect to hydrostatic force due to weight, buoyancy and suction break out, hydrodynamic forces and uncertainty arises due to any external disturbances. In the secondary model, the purging of gas through the valves is taken as the control parameter by accounting the excess buoyancy available after suction break out and to the variation in pressure difference between gas inside lift bag and surrounding sea water pressure for a stable ascent.7318 Руб.
This book presents dynamics of multiple double layers developed in front of a positively biased electrode during high pressure glow discharge in a toroidal vessel of tight aspect ratio. The plasma parameters measured on poloidal plane, at various toroidal locations (near and far from anode), show signatures of double layer formation. Although glow discharge (without magnetic field) should be independent of device geometry, but the stringent boundary conditions imposed by the simple toroidal geometry generate conditions conducive for plasma to grow in size and eventually occupy the entire volume of the device. Double layers have found various applications in basic plasma laboratory experiments, material science and futuristic rocket thruster technology. An objective of this work is to explore some innovative features and applications of such versatile source of plasma generation in a toroidal magnetized confinement. This book is meant for Plasma Physicists, researchers and all those ingenious minds, in the field of basic as well as advanced research, who are consistently working towards harnessing the magic of plasma for the greater benefit of humanity.3600 Руб.
Refrigeration and its application is met in almost ever y branch of industr y, so that practitioners in other fields find that they have to become aware of its principles, uses and limitations. This book aims to introduce students and professionals in other disciplines to the fundamentals of the subject, without involving the reader too deeply in theor y. The subject matter is laid out in logical order and covers the main uses and types of equipment. In the ten years since the last edition there have been major changes in the choice of refrigerants due to environmental factors and an additional chapter is introduced to reflect this. This issue is on-going and new developments will appear over the next ten years. This issue has also affected ser vicing and maintenance of refrigeration equipment and there is an increased pressure to improve efficiency in the reduction of energy use. This edition reflects these issues, whilst maintaining links with the past for users of existing plant and systems. There have also been changes in packaged air-conditioning equipment and this has been introduced to the relevant sections. The book gives worked examples of many practica7718 Руб.