摘要:

AbstractThe technical and economic feasibility of small‐scale fluidized‐bed furnaces (SSFBF) for providing residential space and domestic hot water heating in Nova Scotia is analysed. A model of the provincial housing stock is developed to estimate the residential energy consumption for domestic space and hot water heating. The number of dwellings in the province is estimated from available statistical data, and the heating equipment in these dwellings is classified by type, age, and principal heating fuel. Market share levels are assumed for the new and replacement residential housing markets, and the number of SSFBFs required for those levels is calculated. The amount of coal water slurry (CWS) fuel used by the SSFBFs is calculated, and the quantities of oil, wood, and coal displaced by the CWS, as well as the number of jobs created by the adoption of SSFBF technology, are estimated.A procedure is developed to design SSFBFs in the 15–250 kW capacity range. Computer programs are developed, based on this procedure, to calculate the furnace design and performance parameters.The manufacturing cost, and the annual fuel and maintenance costs of SSFBFs are estimated, as were the capital, and annual fuel and maintenance costs of various residential heating systems. From these estimated costs, economic analyses are carried out using the annualized cost and total present worth methods.The findings of this work indicate that SSFBF technology is technically feasible, and is economically superior to conventional oil, wood and coal fired systems for residential space and domestic hot water he

ISSN:0363-907X    

DOI:10.1002/er.4440170602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper presents a new computerized procedure for dealing with the design of horizontal ground heat exchangers (HGHE). The computer program is based on the transient model of coupled nonlinear partial differential equations governing heat and mass flow in soils. The model is two‐dimensional and delineates the operation of ground heat storage with the HGHE and such phenomena as freezing/thawing and drying/rewetting of soil moisture. Comprehensive climatological data, such as ambient temperature, solar radiation, wind velocity, rainfall, snowfall, snow characterstics, and water vapour pressure is used to simulate conditions at the ground surface over any required length of time. The package can be applied to any geographical location by changing climatic and soil data input. The designer has the possibility of selecting any of 12 types of soils from sand to clay, 12 commercial heat pumps, nine different configurations of the HGHE, 16 plastic pipes for ground coils, and 13 ground coil fluids. The program, however, does not calculate the length of the HGHE but it evaluates the thermodynamic performance of a ground heat pump system and provides comprehensive data on thermal and hydraulic conditions in ground heat storage. The length of the ground heat exchanger is obtained from a line source theory model or from site dimensions and pipe spacing. Computed results for ground heat exchanger operation correlate fairly well with experimental data. Simulation of temperature and moisture content in the ground for natural conditions (no heat extraction/deposition) showed a fair agreement with field data. The entire computer program is user‐friendly, interactive, menu‐driven, and written in FORTR

ISSN:0363-907X    

DOI:10.1002/er.4440170603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn experimental investigation under cold condition was made to study the effects of some operating/design parameters and non‐mechanical L valve configuration on the solid circulation rate in a 4.5 m tall, 0.15 m diameter circulating fluidized bed with riser flow rate varying from 1400 litres/min to 2000 litres/min and bed inventory from 15 kg to 25 kg of sand of average sizes 200 μm, 400 μm and 500 μm. Solid circulation rate was estimated by measuring velocity of sand particle travelling through a vertical Perspex tube section at the bottom of the return leg. It was found to be in the range of 2.8 to 12.3kg/m2s, 0.07 to 9.1kg/m2s and 0.12 to 2.23kg/m2s for sand sizes of 200 μm, 400 μm and 500 μm, respectively for a horizontal L valve. Two mathematical correlations have been developed from the experimental results to predict solid circulation rate as a function of riser flow rate, aeration flow rate, total bed inventory and particle si

ISSN:0363-907X    

DOI:10.1002/er.4440170604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn experimental investigation was carried out to study the effects of operating parameters on the local bed‐to‐wall heat transfer coefficient in a 4.5 m tall, 0.150 m diameter circulating fluidized bed with a bed temperature in the range of 65°C to 80°C, riser flow rate varying from 1400 litres/min to 2000 litres/min, bed inventory in the range of 15 kg to 25 kg of sand, and average sand sizes of 200 μm, 400 μm and 500 μm. A heat flux probe was attached to the riser wall at five different vertical locations for measuring the heat flux from the bed to the wall surface. From the present work, the heat transfer coefficient in the dilute phase was found to be in the range of 62 to 83 W/m2K, 51 to 74 W/m2K, and 50 to 59 W/m2K for sand sizes of 200 μm, 400 μm and 500 μm, respectively. Relevant mathematical correlations were developed to predict local heat transfer coefficient based on the results of the pra

ISSN:0363-907X    

DOI:10.1002/er.4440170605

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractStrategic energy planning is concerned with investments in energy technologies with long lead times and long life times. Of special interest are uncertainties about future developments that could lead to a major reappraisal of the cost‐efficiency of different energy technologies. Decision making in this context is concerned, therefore, with finding a solution to the decision problem which is both low‐cost and robust. Here, a method is described for using hedging to improve the robustness of the energy system. The method is applied using a standard energy systems model, MARKAL. It is shown how the model results can be used for a quantitative analysis of the robustness of the energy system. A study of the Swedish energy system is used as an example, where the uncertain factor is whether or not future restrictions on CO2emissions will be impo

ISSN:0363-907X    

DOI:10.1002/er.4440170606

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractOne of the most important determinants for the design of the future energy system is whether or not constraints on CO2emissions will be imposed. Here, this issue is treated as a decision under uncertainty. Three strategies have been considered: immediate action to adapt to a future emission constraint (Commitment), business as usual (No Hedging), and hedging (Hedging). In the case of hedging, preparations are made outside the energy system, but the energy system itself is allowed to develop according to baseline assumptions until the uncertainty has been resolved. The IEA‐MARKAL model has been used to show how efficient and robust the three strategies are under different developments. The development of the Swedish energy system has been studied for two rates of economic growth in combination with three nuclear policies and two CO2policies. The value of preparations for meeting a possible restriction on CO2emissions, i.e., following either the Commitment or the Hedging strategy, is considerably higher when the energy demand increases rapidly. In the low growth case, the choice of strategy is largely dependent upon the decision maker's estimate of the likelihood of an emission cap. In the high growth case, this likelihood must be considered to be very small in order to choose the No Hedging strategy, even with reinvestments in nuclear capacity beyond 201

ISSN:0363-907X    

DOI:10.1002/er.4440170607

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper reports the results of energy analysis of oil‐ and coal‐fired systems in a sodium silicate industry, in a mechanized bakery and in silk filatures. In all, seven systems (three oil‐fired and four coal‐fired units) were evaluated and energy conservation measures were suggested. It is shown that in most cases, the fuel consumption can be reduced by over half. The recommendations for fuel savings and mathematical simulations are valid for similar systems el

ISSN:0363-907X    

DOI:10.1002/er.4440170608

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440170609

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0363-907X    

DOI:10.1002/er.4440170601

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY