Hog fuel is a broad term used by the forest products industry to describe all types of wood residues that are used as fuel. These can be bark, wood chip rejects, sawdust, shavings, etc. The moisture content of these residuals depends mainly on their source and on the conditions of storage and could range from 50 to 70% (wet basis). The introduction of the significant amounts of water contained in the hog fuel impairs the efficiency of operating a hog-fuel boiler by: (i) reducing the net heating value of the fuel, (ii) increasing the particulate emissions caused by incomplete combustion, (iii) requiring higher air flows to maintain combustion, (iv) decreasing the rate of combustion, and (v) reducing the heat flux as a result of lower flame temperatures. Several drying systems are commercially available for the drying of hog fuel and most of them use the waste heat in the flue gas as the source of heat for the drying operation. Commercial flue gas dryers are rotary, cascade or flash type. However, all of these suffer from the same inherent disadvantages.
A common feature to current noise control in ventilating systems is their computing the attenuation due to the elements of the network, each considered separately. In doing so, they miss accounting for the interactions between these elements and they cannot represent or model large systems to simulate optimum control. In this paper, we draw a modeling approach which, in using an equivalent electrical network, has the potential to meet this limitation; then, give a brief description of programming considerations. Next, the authors show the use of the program and the accuracy of the model we have used. To this end, we first have compared the attenuation due to some simple networks with experimental results, and then we will show the application of the program to a large network and compare the results with those obtained by other methods. Finally, the authors show how an efficient noise control may be achieved thanks to our program and how it is possible to optimize the shape, size and location in the system of silencers to satisfy any noise level requirements.
Many new energy technologies appear at the household level as negative loads. These can be tightly coupled with other household loads through a common weather dependence, creating distributions of demand which are unlike those in homes without alternative energy sources. Knowledge of these load interactions requires either customer monitoring or a scheme to forecast weather-dependent end-use loads. Previous models of weatherdependent loads included the nonlinear functions of Galiana renewal process models, such as Chong, detailed simulations as developed by Chan, and state models, such as Ihara and Calloway. A common feature of these models is the use of a linear relation between demand and some weather variable, once thermostatic controls are considered. Furthermore, they neglect the cyclical time patterns of end-use demands in order to focus on the physics of weather-dependent phenomena. In this paper two ideas based on Woodard and Ruane are combined to introduce non-linear treatment of weather dependence simultaneously with a compact representation of the various cyclical patterns present in weather dependent loads. Model development is presented and empirical results given based on the analysis of utility end-use electric space heating data.
This study deals with the different aspects of residential home energy criterias and regulations, so that any one with basic knowledge can study and use it the best way for their application. A simplified home energy management approach for new residential homes and the existing (old) homes has been developed. The different aspects of the maximum energy use have been discussed for the residential buildings. A home energy audit and analysis procedure with sample calculations for a residential building is also included.
This paper examines the various energy sources, renewable and nonrenewable, in the context of developing and industrialised countries. Particular experiences and technical data are mentioned regarding the United States' experience in this area and the Public Utilities Commissions of various states. The author has gathered various technical information on energy generation and public policies on energy issues while associated with the Public Utility Commission as a staff member and having testified as expert witness in a number of electric energy rate cases in Pennsylvania, North Carolina and West Virginia. This paper surveys the available alternate energy technologies to meet the energe needs at the village level, with particular reference to their application in Pakistan. This paper concludes after analysing the various energy choices as to the resources, policies and energy education development. The author has proposed small workshops at the high school level for students and teachers, based on the same concepts developed by the Department of Energy. Development of advanced research and cooperation in ''renewable energy resources'' through A.I.D. programs is recommended.
Combustion modification technology has enabled many utility boilers to meet the NOx emission standards. Since the technology involves modifications in either the combustion or the operating conditions, it is expected to have some effect on the performance of the plant or boiler. This paper, therefore, outlines some of the important NOx control techniques and their influence on plant performance, thermal efficiency, and efficient utilization of fuel and energy. In general, the NOx control technology involving reduced excess air operation and/or staged combustion is plagued with increased CO and smoke emission and increased loss of fuel as carbon NOx. For example, a 400 MW plant loses about one million dollars a year on fuel for operating at low excess air. These techniques also show an increasing or decreasing effect on fuel saving and boiler performance depending on the fuel type, technique, and operating conditions. Techniques such as reduced air-preheat temperature and flue gas recirculation which reduce flame temperature control thermal NOx, but have some effect on thermal efficiency as well as fuel savings. About 3% of fuel savings is lost by reducing the air-preheat temperature by about 100 K, while no noticeable consequence is reported by recirculating the flue gases andmore » by the thermal Denox process.« less
In this paper detailed analysis of wind energy output at 10 places based on IMD data (1958-68) are presented. Windspeeds are recorded and averaged over definite time intervals. When estimating the energy in the wind flowing through unit area in unit time, called wind energy flux (WEF), the cube of the wind speed is required. When the wind speed is averaged, periods of high wind speeds are balanced against periods of low wind speeds. Applying a cube relationship emphasises the high wind speeds more than the low wind speeds. Thus the longer the averaging intervals, the greater the smoothing effect and the smaller the estimate of the WEF. Smyth and Cherry analysed 16 years of hourly data from 10 anemometer stations throughout New Zealand. They derived empirical methods for estimating the mean WEF that would have been given by hourly mean wind speeds using longer period data, such as daily mean wind speeds.
Modern agriculture is an energy consumer sector, also agriculture is an energy conversion process. In addition to biomass energy's raw materials are harvested by agriculture. The concept of energy in agriculture, energy is one of the main and outstanding factor which renders the realization of the overall development of the agriculture and rural areas. Agricultural income depends on total mechanical power in agricultural mechanization; general energy consumption of rural sector; cultural energy consumption by agricultural inputs which are fertilizer, pesticides, indirect energy in machinery, irrigation equipments, buildings and other services; direct energy consumption in agricultural mechanization which are fuel and electricity etc. In general, energy input in the rural areas is classified as direct and indirect. Direct energy input reflects demands for mechanical energy, electrical energy and heat energy. Indirect energy consists of inputs which have been produced by industrial sector and introduced into rural sector. Although conventional energy sources, especially petroleum products are used in meeting direct energy input requirements, alternative energy sources may be used as well in this respect. Especially emphasis is being given to new and renewable alternative sources for heat and electrical energy requirements.
Late in 1982, the author was asked to think about solar mirrors in space. Reference is made to an approach described in the literature as the ''one-sun'' solution. Elements of an alternate in-space reflection system are listed and described. Practicality of shipment, deployment, refueling and maintenance in space is addressed. Overall collection parameters and efficiencies are assessed. Effects on aircraft and birds are described. Possible political problems are considered.
The use of noble metals supported on TiO/sub 2/ has recently received considerable attention in the area of photoassisted reactions at gas/solid or liquid/solid interfaces, because dramatic improvements in the rates of various heterogeneous reactions are achieved with this system over the rate on bare TiO/sub 2/. It has become apparent that reaction rates and product distributions are dependent on: the defect doping densities employed to activate the TiO/sub 2/ substrate, the level of noble metal loading, and the method of noble metal deposition. In an effort to elucidate the role of each of these factors, sintered TiO/sub 2/ electrodes are prepared over a wide range of doping densities at various levels using bulk doping, photodeposition, and sputtering techniques. The effects of these different electrode fabrications on the rates of several catalytic and photocatalytic probe reactions will be considered for the hydrolysis of water and the oxidation of alohols in the production of storable fuels such as hydrogen.
Considerable amount of work has been done on the preparation and characterisation of solar selective films of sulphides and oxides of nickel, coated on commercially available substrates. These materials have shown promising characteristics as an efficient photothermal converter indicating values of solar selectivity (..cap alpha..s/epsilon..mu..) between 5.0 and 13.7. All the studies are made on black nickel films obtained on GI substrates by using electrolytic deposition techniques. For the economy of the overall solar collector system it is not only important to consider the solar selective properties of the surfaces but one has also to take into account the factors like the production cost, large area fabrication criterian, mechanical, thermal and chemical deteriorations of the system during the progress of its usage. In the present investigation, black nickel films were prepared in the laboratory by using spray pyrolysis techniques which is now very widely in use and is relatively a less expensive process. In the past, though these black nickel films were studied by several workers, this technique, namely, the spray pyrolysis has not been exploited. Films were prepared on GI substrates by spraying 0.1 M% solution of AR grade nickel chloride and thiourea mixed in different volum ratioes. Goodmore » adherent and thermally stable films in the thickness range 5-10 ..mu.. have been obtained which showed selective values in the range 11-12.5. In this paper some results on the studies on x-ray diffraction, SEM, EMA (Electron microprobe analysis), and photothermal properties of black nickel are presented and discussed.« less
The primary objective of this paper is to introduce some frequency domain techniques in the design of the optimal feedback control systems of a nuclear reactor or power plant. Although the optimal frequency domain theory developed successfully in the past twenty years, but it is rarely used in the optimal design problems of a nuclear dynamic system. In many circumstances, the frequency response methods are simple and effective to be used. It is hoped that the frequency domain methods may be developed in parallel with the time domain methods in the design of the optimal nuclear dynamic systems. The above-cited methods can be used in the control system design of a thermal or fast reactor as well as a nuclear breeder.
By addition of 0.3% NH/sub 4/HCO/sub 3/ instead of animal manure into rural biogas digester in which the rotted rice straw was the major feedstock, the biogas yield doubled in comparison with the check digester (0.1 m/sup 3//m/sup 3//d) and the fertility of NH/sub 4/HCO/sub 3/ did not decrease because of biogas fermentation. Many digesters have been built in China. But, owing to the problems of improper management, unsuitable influent mixing, etc., neither digesters nor feedstock were fully utilized. In order to solve these problems, adding NH/sub 4/HCO/sub 3/ into digester instead of animal manure was tried. Its results showed that the suitable C/N ratio of influent mixing was obtained, the fertility of effluent went up, and biogas producing rate increased. The concentration of NH/sub 4/HCO/sub 3/ is 0.2-0.6%, but the optimal is 0.3%.
The process industry studied involves 5-day cycle hot water curing to be maintained at 50/sup 0/-55/sup 0/C. In the old practice, hot water at 80/sup 0/C from fuel oil boiler is charged into open pits to submerge components to be cured. Whenever pit water temperature falls below 50/sup 0/C, two-third of this water is pumped out and is replaced by fresh 80/sup 0/C water. Energy auditing revealed that evaporation losses from the open pits is very high. Airplast sheet was used as flexible cover, which drastically reduced the losses by 60-70% resulting in 45.5% reduction in fuel oil consumption. The loss rate of the pits reduced from 1.5-2.0/sup 0/C/h to 0.3-0.9/sup 0/C/h for underground pits. Heat is recovered also from pit water drained at 50/sup 0/C to preheat cold incoming water. 58% heat recovery was found optimum. Solar water heater was retrofitted providing annual solar fraction of 27.6%. A close loop system was preferred to avoid scaling. A differential temperature controller is used to switch on/off the circulation pumps.
In this study a vertical sintering oven is constructed and instrumented to enable a realization of sintering experiments of bronze inside capper tubes. The sintering oven consists of ceramic core around which is rolled helical electrical resistance of KW in power. The outside shell is made up of an iron tube and is thermically isolated. A thermocouple passes through the top cover and is perfectly isolated and sealed. This thermocouple is used to measure the average temperature of the oven. The tube to be sintered is hung inside the ceramic tube. In order to ensure an inert atmosphere, a small diameter tube is soldered to the top cover and is connected to a helium gas cylinder fitted with a pressure regulator. In these experiments various particle sizes were used. Various sintering temperature and times. After the tubes are sintered, they are removed and tested hydrodynamically to verify the pressure drop and measure the permeability. Results are plotted showing the effect of temperature and residence time on these parameters. Selected tubes are then prepared as heat pipes and put for testing to determine the thermal performance of the tubes. Parameters such as working temperature, mass of working fluid, angle of inclinationmore » are investigated, analysed and discussed. It is found that heat pipes with sintered material have a reasonably good thermal performance as compared to mesh wicked tubes. Another advantage is that sintered tubes are easy to fabricate and prepare and thus the fabrication cost is much below mesh wicked tubes. It is hoped that this cost reduction will allow large scale use of these tubes in heat exchangers and energy recuperators.« less
This Paper presents a new continous operating solar desiccant absorption system in which CaCl2-H2O is used as the absorbent. The flat-plate solar collector is utilized as the desorber where water from the solution is evaporated to ambient air in passing over the collector above the solution film. The plant is equipped with a latent heat accumulation system which is extremely compact in size and very efficient. The coefficient of performance—solar collector efficiency product, indicating the grade of solar energy utilized, is estimated as being the highest of all presently known systems.
A dimensionless analysis of matrix air heaters has been developed to study the effect of different boundary conditions on its performance. The theoretical results have been compared with the measurements of an experiment performed with one type of matrix solar air heater. For one set of boundary conditions, the theoretical results agree fairly well with the experimental data, thus providing confidence in particular boundary conditions. For this particular set of boundary conditions, the thermal performance of the system has been studied for different mass flow rates of air and as a function of matrix thickness.
This paper reports on the development of a database for the computer program, SYSBLD2, which generates solutions to a limited set of problems in housing design: passive solar multi-family housing: from a database of apartment plans, their components, and their associated economic and energy analysis. While the program has been designed to provide graphic output, the simplicity of its primitives eliminate the need for a complex data structure to represent the building geometry.
There has been and continues to be a perceived need for the fusion energy option in our energy future. The National Energy Plan states that ''the Federal Government recognizes a direct responsibility to demonstrate the scientific and engineering feasibility of fusion''. The goal of the program, in exercising this responsibility, is to develop the knowledge base upon which decisions on the commercial feasibility of fusion will be made after the conclusion of the present scientific feasibility phase of the program. The strategy is to preceed sequentially through a product definition phase, to the product development phase. Product definition is the identification of an attractive fusion reactor concept supported by a sound base of scientific and technological information. Product development is the further refinement of scientific, technological and engineering information base of the selected concept to provide a firm basis for commercial application. Each of these phases will be discussed with special emphasis on the relationship between the annual appropriation process and the influence of external forces on the pace of the program. This discussion will include the use of international cooperation to maintain and extend program scope. Further discussion will cover the important scientific and technological advances of the lastmore » few years and the way in which they have influenced the development of our management strategy to maximize our resources.« less
