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1.
John P. Weyant 《Energy》1978,3(6):701-735
The benefits attributable to alternative energy R & D programs should be evaluated in terms of how well the technologies contribute as integral elements of the total United States energy system (rather than as isolated entities, as has typically been done in the past). Thus, the present model simulates the dynamics of the evolution of the total energy system by requiring both existing and new technologies to compete for introduction (i.e. commercialization) on a cost-competitive basis that considers the time phasing of
1. (1) retirement of energy conversion facilities,
2. (2) growth in end-use demands, and
3. (3) escalation of the costs of extracting depleting domestic energy resources.
This approach contrasts with a static model used by the Energy Research and Development Administration (ERDA), wherein assumptions must be made for each future year of interest for
1. (1) maximum capacity constraints for alternative types of conversion facilities and
2. (2) the cost of energy resources.

The present model is used to compare the relative consequences and merits of the technology products from the following three of ERDA's major energy R & D programs:

1. (1) the liquid-metal fast breeder reactor (LMFBR),
2. (2) synthetic fuels derived from coal and oil shale, and
3. (3) improved efficiencies for end-use devices (e.g. space heaters).
It is found that the development of synthetic fuels derived from coal and oil shale is the only alternative (of the three considered) that provides energy independence for the United States in the next fifty years. However, the possible collapse of the world oil cartel is shown to pose a major retardant to synfuels commercialization by the private sector until at least the end of the century. The substantial environmental impact from synfuels commercialization could be reduced significantly with the accelerated introduction of end-use utilizing devices with improved efficiencies. This latter program could result in a significant reduction in the costs of operating the United States energy ststem over the 60-yr period considered by the model. The discounted present value of this “cost reduction” (i.e. the “economic benefit”) would be two orders of magnitude greater than the R & D investment, at least one order of magnitude greater than the expected economic benefits from synfuels commercialization and two orders of magnitude greater than the economic benefits from the commercialization of the LMFBR. However, the lack of performance and cost studies of improved efficiency in end-use suggests increased funding for these technologies rather than reduced funding for the breeder.  相似文献   

2.
In recent years it has been recognised by an increasing number of nations that there is considerable energy potential within MSW. As a result many countries have established R,D& D programmes to examine methods of exploiting this potential. The IEA's MSW Conversion Activity was set up in 1986 to provide an infrastructure for sharing information and co-ordinating work in this area internationally. This Activity was extended in 1989 and currently a total of 9 nations participate in it.

To cope with the wide scope of the area (encompassing both biological and thermal processing of MSW) the Activity was divided into three subgroups or Expert Working Groups (EWGs). Each of these dealt with a distinct area of expertise:

1. •Downstream effects of source separation and screening of MSW
2. •Sampling and analytical protocols
3. •Landfill gas

In addition to these groups a central secretariat based at Harwell (UK) has provided guidance, established and administered databases of contacts and produced a series of national reports.

This paper describes the achievements of the Activity and discusses work proposed for the future.  相似文献   


3.
This paper deals with computer simulation of the PC isotherms of some ZrFe2 type (Zr(Fe1−xCrx)2, Zr1−xTixFe1.4Cr0.6, Zr1−2xMmxTixFe1.4Cr0.6 : x00.4) of hydrogen storage materials. A feasible mathematical model has been developed to simulate the PC isotherms. The randomized variables in the model applied for simulating the PC isotherms of the above-mentioned ZrFe2 type hydrogen storage materials correspond to change in enthalpy (ΔH) and entropy (ΔS) of hydride formation. Several ZrFe2 type materials as in above have been synthesized and their PC isotherms, enthalpy and entropy change has been evaluated experimentally in order to have input data for simulation. A special software was developed to simulate the PC isotherms using the said model. A close match between the experimentally observed and simulated PC isotherms for the above said ZrFe2 type alloys has been obtained.  相似文献   

4.
In this nonsalt type of solar pond, the nonconvecting layer is composed of a viscous polymer solution partitioned by a number of transparent films. An advantage of partitioning is that a thinner polymer solution can be used and that the light transmittance increases. Results of experimental and theoretical investigations on the performance of this solar pond are summarized as follows:
1. 1. Ionized polyacrylamide solution was chosen as the thickener based on tests about solubility, viscosity, light transmittance and stability.
2. 2. The critical temperature difference for the onset of convection in the polymer layer (ΔT/L)cr [°C/m] was given by the following formula based on the measurements in various thicknesses of the polymer layers (L) [m] and various concentrations (ζ) [%],
T/l)cr=(55−185lnL)exp(4.66L0.505lnζ
3. 3. An outdoor model pond, 200 × 150 cm surface and 100 cm depth, was constructed in Osaka. Four types of model ponds were tested, and the availability of membrane type with partition films was confirmed.
4. 4. The theoretical temperature rise of the pond using a one-dimensional model was calculated by solving the equations of the heat balance in the pond. As a result, the optimum values of thickness of polymer layer and number of films was determined
  相似文献   

5.
S.S. Penner 《Energy》1976,1(4):407-412
Using Budyko's overall heat-balance equation, we estimate that direct heat addition associated with worldwide energy use in the year 2050 will be responsible for a mean global temperature rise of 0.27 °C at a 20 kwt per capita energy consumption for a world population of ten billion people. The corresponding temperature rise between 15 and 60 °N is estimated to be 0.44 °C. If per capita energy consumption during the year 2050 is reduced to 5 kw, (i.e. about one half of U.S. consumption in the year 1970), the estimated temperature rise for the 15–60 °N latitudinal belt will be about 0.11 °C and therefore still not negligibly small.

A program for monitoring the global climatic impact of escalating energy use involves precise monitoring of the following quantities:

1. (a) the solar constant
2. (b) the effective earth-atmosphere albedo
3. (c) the net (long-wavelength) radiant energy emitted from the earth-atmosphere system.
Both the effective albedo and the (long-wavelength) radiant energy emitted from the earth-atmosphere system will depend on the nature and size of particulate concentrations in the atmosphere, on molecular emitters (especially CO2 and H2O), cloud cover, and on the radiative-convective circulation pattern. A satellite observation program that is closely integrated with ground-based and atmospheric measurements and with a detailed program of theoretical analysis will be needed for more precise predictions of inadvertent climate changes and for developing the means to effect desirable global climate controls.  相似文献   

6.
Eric Hirst 《Energy》1994,19(12):1193-1203
This paper discusses competition in the electricity industry and how it might affect utility DSM programs. The roles that state regulatory commissions could play to affect retail competition and DSM programs are examined. Commissions could set exit or reentry fees for customers who want to buy electricity from an entity other than the local utility. Or they could ‘tax’ the use of the local distribution system to discourage uneconomic wheeling and to pay for DSM programs. The effects of DSM programs on retail electricity prices and how utilities might redesign their DSM programs for a more competitive environment are considered. In the future, utility DSM programs may
1. (1) focus more on customer service and less on system-resource benefits,
2. (2) emphasize capacity reductions more and energy savings less as utilities seek to minimize the lost revenues associated with DSM,
3. (3) become more cost-effective as utilities identify better ways to deliver DSM services at lower cost, and
4. (4) involve fewer inter- and intraclass transfers as utilities increasingly have individual customers pay for their own DSM services. While DSM programs in the future may be different from what they are today, they will continue to be important to utilities as powerful marketing tools and to society because of their environmental and economic-productivity benefits.
  相似文献   

7.
The optimal spacing of parallel plates cooled by forced convection   总被引:4,自引:0,他引:4  
This paper reports the optimal board-to-board spacing and maximum total heat transfer rate from a stack of parallel boards cooled by laminar forced convection. The optimal spacing is proportional to the board length raised to the power 1/2, the property group (μ)1/4, and (ΔP)−1/4, where ΔP is the pressure head maintained across the stack. The maximum total heat transfer rate is proportional to (ΔP)1/2, the total thickness of the stack (H), and the maximum allowable temperature difference between the board and the coolant inlet. Board surfaces with uniform temperature and uniform heat flux are considered. It is shown that the surface thermal condition (uniform temperature vs uniform heat flux) has a minor effect on the optimal spacing and the maximum total heat transfer rate.  相似文献   

8.
The total energy requirements of household consumption of all goods and services have been calculated. Source for consumption data is the 1972–1973 Bureau of Labor Statistics (BLS) Consumer Survey. These are converted to energy terms using input-output energy intensities. The dependence of household energy use on expenditures, number of household members, degree of urbanization, and other demographic-economic factors, has been investigated graphically and statistically. The major factor determining energy requirement is expenditure level, but this can be affected by up to about 15% by variation in the other factors. In agreement with previous work based on the 1960–1961 BLS Survey, we find that
1. (1) the dependence of total energy requirements on expenditures shows a tendency to saturation;
2. (2) about one-half of the total energy of the average household is a result of the purchase of fuels and electricity while the other half results from the purchase of non-energy commodities.
Application to the analysis of an energy tax and rebate program is discussed briefly.  相似文献   

9.
Hourly, daily, monthly and annual heating and cooling requirements of a residential building located in Ottawa, Ontario, Canada were estimated, employing ENERPASS as the energy simulation tool, and performing hour-by-hour energy analysis. The following weather data were employed:
1. (i) Ten years (1967–1976) of weather data. The ten-year average of the results is identified as TYA.
2. (ii) A typical meteorological year (TMY) generated using the same ten years of data.
3. (iii) Two different hourly ambient air temperature distributions (T1 and T2) for a typical day in each month. The solar radiation on each surface was estimated using the mean monthly clearness index.

The house use patterns, including heat generation and the thermostat setting, were taken the same when using TYA, TMY, T1 or T2. The analysis was carried out for the house as it is (well insulated and airtight), and for two modifications: one with larger infiltration rate and lower wall thermal resistance, and the other with larger south-facing window area and using super-windows. The results of this study show that the long-range hourly, daily, monthly and annual heating and cooling requirements of a residential building located in a cold climate can be predicted by employing mean daily maximum and minimum temperatures and the mean monthly clearness index for each month. This amounts to substantial savings in computational costs, in either using many years of weather data or generating a TMY for the site. For locations lacking detailed hourly weather data, the use of data and the procedure outlined in this study may be employed to predict the long-range thermal performance of simple residential buildings.  相似文献   


10.
A two day meeting involving researchers, industrialists, and state policymakers on the subject of coal technologies and synfuels brought general agreement on:
1. (1) the lack of a cohesive energy policy regarding coal in the United States;
2. (2) the need for long-term constancy in the regulatory environment;
3. (3) the need for coal research and development; and
4. (4) the use of conflict resolution techniques to solve synfuel issues.
  相似文献   

11.
Enthalpy management requirements of residential and small commercial buildings are analyzed and integrated approaches to energy-efficient and cost-effective heating and cooling schemes are proposed. Improved design and operating strategies are suggested to make more efficient use of off-the-self (or other readily accessible) technology for space conditioning. The use of Comfort Range Thermal Storage (temperatures in the approximate range of 65–75 °F) and special operational strategies are central to these approaches. Fossil-fuel heaters, heat pumps, solar collectors, electric driven air coolers, all can be used more efficiently when they are effectively interfaced with selected thermal storage systems. A central heated (fossil fuel) and cooled (electric air-conditioner) residence located in Long Island, New York, is considered as an example. With Comfort Range Thermal Storage, it is found that the revised operating approach leads to 50% savings in space conditioning costs, with the basic functional features of the building unchanged from those of a typical well-insulated frame residence. Additional insulation results in further savings.

Devices, methods and strategies employed to achieve these results include the use of Comfort Range Thermal Storage as well as one or more of the following:

1. (1) Variable firing rate fossil fuel heater.
2. (2) Thermally purgeable fossil fuel heater.
3. (3) Outside air for all fossil fuel heater requirements.
4. (4) Separation of the combustion and heat transfer function from the thermal storage function of a conventional boiler.
5. (5) Use of off-peak electrical energy.
6. (6) User-oriented controls for space conditioning applications to allow conscious reprogramming of temperature to suit variations in life-style of the occupants.
7. (7) Control of energy flow at windows during the heating and cooling seasons.
8. (8) Comfort Range Thermal Storage in the temperature range of 65–75 °F.
9. (9) Functionally composite building materials.

Not all the above options are suitable for inclusion in new structures. Not all can be retrofitted to existing structures. Nevertheless, substantial energy and cost savings are selectively possible in all cases of fossil-fuel heating systems. Retrofitting of existing masonry buildings promises particularly significant economies. Such structures are typically uninsulated. Retrofit strategies which include insulation, permit economies substantially greater than those which result solely from the insulation-prescribed reduced heat losses. Such retrofitting, as well as the retrofitting of substantial thermal storage capacity to existing insulated frame buildings can result in substantial cost reductions for space heating and cooling.  相似文献   


12.
D. Proctor 《Solar Energy》1973,14(4):433-436
There are instances in remote areas where heat is being wasted, e.g., in internal combustion, engines, etc. Some of this heat can be recovered to produce distilled water in solar stills.

The solar still replaces the cooling tower, ponds, or radiators normally used to control the engine temperature. The diesel cooling water in such a system remains separate from the saline water in the solar still.

The advantages of using such a system compared with a conventional solar still are:

1. (a) water costs are very much reduced
2. (b) the area occupied is much less, i.e., about 1/5th
3. (c) production has much less seasonal variation
4. (d) the efficiency of the solar still is improved due to the higher operating temperatures.

From experiments conducted at Highett using a Mk VI solar still fitted with a simple heat exchanger and a separate electrically-heated source of hot water to simulate the waste heat, design data are not available for application to working systems. The information required to match a solar still to a diesel's cooling requirement is:

1. (a) engine efficiency
2. (b) hourly fuel consumption
3. (c) hourly solar radiation
4. (d) hourly ambient temperatures.

A by-product of this work has been the production of a “solar water heater” which costs less than that of the cheapest conventional system. This “solar” hot water system uses a heat exchanger similar to what is used to transfer the waste heat to the saline water. It is envisaged to have hot water productions approximately the same as the distilled water productions. The influence of hot water production on the output of the waste heat solar still is discussed.  相似文献   


13.
Mainly the economic aspects prevent a far more extensive use of biomass, including straw as a fuel in energy supply.

During the latest years several straw fired plants have been put in operation, especially in Denmark, and they have demonstrated that both district heating and combined heat and power (CHP) production based on straw are technically possible.

However, experience has shown that a very precise research and development effort is necessary before the straw fired plants are competitive to traditional plants fired with fossil fuels, as to operational safety and economy.

The R & D activities ought first and foremost to aim at: 1) Reduction of costs connected to all processes from harvest to energy production, 2) wider know-how of the firing and combustion technical characteristics of straw, and 3) environmental conditions, including emissions and ash depositing problems.  相似文献   


14.
Based on the solutions of through-cracked strip, the constitutive relations of line-springs for embedded crack and slightly emergent surface crack are formulated for the first time. The line-spring model has been improved with the aid of a three-dimensional solution of embedded elliptical crack in an infinite body to include the curvature effects of surface crack front, i.e. the interaction between springs. The calculated results from the improved model are very consistent with those from the alternative iteration reported previously (Shah, R. C. & Kobayashi, A. S. J. Pres. Vessel Technol., 1 (1974) 47–54); the improved model has higher precision and a larger effective range than the unimproved model.  相似文献   

15.
Discussions on the role of biomass in the development of a midwest synfuels industry brought general agreement on:
1. (1) the continued development of new techniques for ethanol production;
2. (2) use of corn as a feedstock for ethanol;
3. (3) large-scale plants are more economical than farm-scale ethanol plants; and
4. (4) tax subsidies to promote use of ethanol.
  相似文献   

16.
FeTi-samples have been prepared and characterized by metallography, X-ray diffraction, neutron diffraction and specific heat measurements. The conditions for the presence of the ordered CsCl structure at room temperature have been investigated. This material has been used to study FeTi-hydrides, especially the structure, phase transition and the heat of reaction as a function of the hydrogen concentration. The heat of reaction is 30 kJ/mole H2 for 0.05 < c < 0.5 (c = atomic ratio: atoms H/atoms metal). The heat of solution (c → 0) is approx. 130 kJ/mole H2. The FeTi material has been used to build and operate a small hydrogen storage container (1 Nm3H2) as an alternative to high pressure hydrogen gas containers in the laboratory.  相似文献   

17.
A fan-stirred combustion chamber is deve-loped for spherically expanding flames, with P and T up to 10 bar and 473 K, respectively. Turbulence characteristics are estimated using particle image velocimetry (PIV) at different initial pressures (P = 0.5–5 bar), fan frequencies (ω = 0–2000 r/min), and impeller diameters (D = 100 and 114 mm). The flame propagation of methanol/air is investigated at different turbulence intensities (u′=0–1.77 m/s) and equivalence ratios (φ = 0.7–1.5). The results show that u′ is independent of P and proportional to ω, which can be up to 3.5 m/s at 2000 r/min. LT is independent of P and performs a power regression with ω approximately. The turbulent field is homogeneous and isotropic in the central region of the chamber while the inertial subrange of spatial energy spectrum is more collapsed to –5/3 law at a high ReT. Compared to laminar expanding flames, the morpho-logy of turbulent expanding flames is wrinkled and the wrinkles will be finer with the growth of turbulence intensity, consistent with the decline of the Taylor scale and the Kolmogorov scale. The determined SL in the present study is in good agreement with that of previous literature. The SL and ST of methanol/air have a non-monotonic trend with φ while peak ST is shifted to the richer side compared to SL. This indicates that the newly built turbulent combustion chamber is reliable for further experimental study.  相似文献   

18.
Reliability of multilayer ceramic capacitors with nickel electrodes   总被引:3,自引:0,他引:3  
The reliability of multilayer ceramic capacitors (MLCCs) with Ni internal electrodes has been studied trom the viewpoint of partial oxygen pressure (PO2) during firing. It is shown that the load-life time of the insulation resistance (1R) was prolonged by firing under low Po2 annealing after firing, and the addition of dopants. It is also shown that the generation of oxygen vacancies led to the degradation of IR. Annealing treatment for the oxidation of the dielectric body accelerates the dielectric aging of MLCCs. It is found that the appropriate control of the PO2 during firing can improve the reliability of MLCCs with Ni electrodes to a level as high as that of MLCCs with precious metal electrodes. Thus, we have developed an MLCC with Ni electrodes that features high reliability and a large capacitance of 10 μF for the Y5V characteristic and 4.7 μF for the X7R characteristic, both in the case of the C3216 (3.2 mm × 1.6 mm × 1.4 mm) form.  相似文献   

19.
The Ce1−xRxNi2.5Cu2.5 (R = La,Pr; 0.8 x 0.3) and PrNi5−xMx (M = Cu, Fe; 0.5 x 2.5) alloys were investigated for their hydriding characteristics in the temperature range 0–70°C and hydrogen pressure range 0.01–50 atm. The nonlinear behaviour of unit cell volume vs x in Ce1–xLaxNi2.5Cu2.5 suggests that both size and electronic effects are involved. The partial replacement of Ce by La and Ni by Cu in CeNi5 causes a substantial reduction in the hydrogen sorption pressures without significantly impairing its hydrogen capacity. It was observed that Fe is more effective than Cu in stabilizing PrNi5-H2. The high values of the molar entropy of hydrogen of the β-hydrides studied, SβH, are attributed to extensive hydrogen disorder in the interstitial sites of the host lattice. A linear correlation between the hydride decomposition pressures (or free energy) and the unit cell volume. Vc, of the host alloys was observed. This behavior is helpful in predicting the stabilities of new hydrides in a given substitutional alloy series.  相似文献   

20.
The objectives of this investigation were to:
1. (1) demonstrate the effectiveness of those refuse-disposal options which possess the facility for energy recovery: for each, an energy-audit approach has been undertaken to achieve this; and
2. (2) highlight those significant features which affect the net energy-outputs of different refuse-disposal options, whose benefits are assessed.

Thus, six UK ‘waste-to-energy’ facilities, which currently accept major quantities of refuse, were examined. In particular, a comparison was made between the net energy-outputs for two procedures: (i) urban incineration of refuse-derived fuel (RDF), and (ii) transferring the refuse, by rail, to a landfill site, from which appreciable quantities of landfill gas were recovered. The energy attractiveness of both incinerators and RDF plants were appreciably higher than those which could be achieved with landfills. Nevertheless, when financial costs of the various options are taken into account, environmentally acceptable landfill is often the recommended solution.  相似文献   


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