03656 Aggregate emission index of air pollutants from coal combustion

03656 Aggregate emission index of air pollutants from coal combustion

15 Environment The thermodynamic cycle performance of alternative refrigerants for R22 is calculated using the cubic equation of state. The performan...

207KB Sizes 4 Downloads 154 Views

15 Environment

The thermodynamic cycle performance of alternative refrigerants for R22 is calculated using the cubic equation of state. The performance of alternative refrigerants was evaluated and potential impact on system design was analysed on the basrs of comparison between results of the thermodynamic cycle and actual system testing. 00103650 Retrofitting R-12 car air conditioner with R-134a refrigerant Al-Rahghi. 0. M. and Niyaz, A. A. lnl. J. Energ), Rcs., 2000, 24. (6), 467474. Refrigerant-12 which is commonly used in air conditioning is among the substances to be phased out internationally. R-134a, which is a chlorinefree refrigerant, is the industry chosen substitute for R-12. In this study, a car air conditioned by R-12 is selected. The car is fitted with appropriate sensors and gauges to measure the car AC performance. First, the performance is measured when it is running with R-12. Careful retrofitting is then made, including adjustment, changing parts, oil and R-12 to R-134a. The performance of the retrofitted AC with R-134a is then measured. Comparison between the two cases is made for different engine RPMs. The AC system was tested twice to see the effect of ambient temperature on the performance. The results of the comparison are very encouraging with better performance on the side of the R-12 case. The results were also compared with car manufacturer’s recommended performance checks, and found to he satisfactory. 00103651 Second-law analysis of multi-effect lithium bromide/ water absorption chillers Lee, S.-F. and Sherif, S. A. ASHRAE Trams, 1999, 105, (I), 1256-1266. In the consideration of the quality of energy over the quantity involved in a process or a system, thermodynamic second-law analysis combined with first-law analysis is ideal. A detailed thermodynamic analysis leads the way to improve thermal systems and their components. Thus, this analysis can he applied as a useful tool for evaluation and improvement of absorption systems. Various configurations of absorption chillers using a LiBr/HZO solution as the working fluid were analysed and compared on the basis of the first and second laws of thermodynamic. These absorption systems include single-, double- and triple-effect cycles. A simulation of these systems was employed first to investigate the first-law performances, while the second-law efficiencies under different operating conditions were analysed by calculating the thermal properties, entropy, and exergy of the working fluids. 00103652 The effect of the Athens heat island on air conditioning load Hassid, S. CI (II. E?iergy crntf Buildings. 2000, 32, (2), 131-141. The effect of the summer heat island of the western part of the Greater Athens area on cooling energy and peak power is investigated using the building energy estimating software DOE2.1.E [DOEZ.l.E User’s Guide, Lawrence Berkely Lab., CA, USA] and measured values of temperature and other meteorological data at selected sites. A very large difference between the cooling energy and peak power in the western area of Greater Athens on one hand and the eastern edge of the heat island on the other hand, is evidenced for the year 1997. The difference is shown to he smaller for the year 1998 though, which was characterized by an exceptionally hot summer, which apparently affected the eastern part of the Greater Athens area more than the western part. The calculations made based on the typical meteorological year of Athens without taking the heat island related effects into account are shown to underestimate both energy consumption and peak power. 00103653 The rebound effect for space heating empirical evidence from Austria Haas, R. and Biermayr, P. Energy Policy, 2000, 28, (6-7). 4033410. This paper focuses on an investigation into the ‘rebound effect’ for space heating in Austria. Different approaches are applied and compared. The most important result of this investigation is that despite the fact that all approaches applied have their weaknesses and some results were not highly significant, the final outcomes of the different approaches show quite good coincidence. They provide evidence of a rebound effect between 20 and 30%. The most important conclusions for energy policy makers are: (i) standards with respect to building codes are very important tools to increase the thermal quahty of new buildings; (ii) owing to prevailing low energy prices a triggering tool, which may be rebates or loans, has to be implemented to increase the efficiency of the building stock. Thermodynamic analysis of an electrochemical 00/03654 refrigeration cycle Newell, T. A. Inr. J. Energy Res., 2000. 24, (5), 443-453. Electrochemical processes may he used to form thermodynamic cycles in a variety of manners. In this paper, an electrochemical cell and fuel cell are combined to form a refrigeration cycle. Water is chosen as an example for the analysis in order to show ideal performance characteristics of such a cycle. Ideally, the system is close to Carnot performance. In actual systems, the electrolyser side of the system must he operated below neutral voltage levels in order to achieve a refrigeration effect. For the water-based system results presented, water mass flow rates less than 6 kg per h are required per ‘ton’ of refrigeration effect for the ideal system. The effects of operating temperatures on cycle efficiency for the example system are also presented.

14

(po//ution, health protection,

safetyj

HEAT PUMPS

00103655 Innovations in vapour-absorption cycles Wu, S. and Eames, 1. W. Applied Energy. 2000. 66, (3). 251 -266. During the past decade, there has been unprecedented research interest in vapour-absorption cycle refrigeration and heat pumping driven by the need to reduce COz emissions related to process and comfort cooling. This paper reviews some recent innovations in vapour absorption-cycle technology, with particular emphasis on the cycle design and fluid selection. The operation and design of innovative cycles are descr.ihed as well as the latest research in working fluids.

15

ENVIRONMENT Pollution,

health protection,

safety

00103656 Aggregate emission index of air pollutants from coal combustion Konieczynski, J. and Pason-Konieczynska, A. Arch. O&r. Srothwiska, 1999, 25, (I), 29-40. (In Polish) A wide range of pollutants accompanying exhaust gases need to be considered in an evaluation of the influence of coal combustion sources on the air quality. These include fine dust, SOa, NOz, CO, HCI, HF, PAH and trace elements. On the basis of these investigations the emission indexes of these pollutants have been determined. The final form of indexes is the dimensionless conventional emission index (CET). The value of CEI is 26 for pulverized coal fired furnaces, 34 for mechanical stoker furnaces and 213 for domestic stoves. It leads to the conclusion that the combustion of hard coal in domestic stoves is eight times more noxious compared with big utility and power boilers. A study of sulfur dioxide distribution over Istanbul, 00103657 Turkey and preliminary results of neural network analysis Tayanc, M. and Saral, A. NATO Sci. Ser., &r. 2. 1999, 57, 313-324. Over Istanbul there are severe air quality problems, these are related to consumption of low-quality fossil fuels and atmospheric conditions. Sulfur dioxide concentration levels were investigated over Istanbul to assess air pollution during the heating seasons in which the concentration levels of air pollutants are higher than during the summer months. Results revealed that the consumption ratio of coal/fuel-oil increased drastically in the 1980s. An optimum interpolation technique, kriging, was used to obtain the spatial distribution of sulfur dioxide over the area. The resultant sulfur dioxide concentration fields showed three critical regions: the Halic basin, the pipliTaksim area on the European side and Goztepe on the Asian side. During the 1995-1996 heating season, the air pollution levels over Istanbul decreased considerably. Important factors responsible for this decrease in pollutant levels were found to he the favourable weather conditions, the switching to natural gas in many buildings and the consumption of pretreated coal. Neural networks were used as the modelling tool in the prediction of air pollution levels and the results produced were encouraging. A data set that contained meteorological and air pollution parameters for a month-long period was used. It is demonstrated that the neural network is extremely reliable as an average error between the actual and predicted sulfur dioxide concentration levels was calculated at 12%. 00103658 Assessment and prioritization of mitigation options in the power sector in India: the relevance of analytical hierarchical process Bhandari, P. M. and Pathak, M. K. Greenhouse Gus Conrrol Tecknology, Proc. hr. Conf., 41/r, 1999, 587-592. Edited by Eliasson B. PI al. The Convention on Climate Change has an ultimate objective which is to achieve stabilization of greenhouse gas (GHG) concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system within a sufficient time frame. In fact, limiting greenhouse gas emissions to specific levels is an internationally recognized objective. Although the developing countries have no commitments to reduce GHG emissions, there are several programmes and policies already in place in these countries, which are sensitive to CO* reduction. In this context, taking the case of India, the authors have analysed options to mitigate COa emissions in the power generation sector. This sector contributes 39% of COa emissions in India. Interventions in this sector are of significance in the context of 63% coal-based generating capacity, which is rather inefficient. For an assessment and prioritizing of the mitigation options, the HIPRE (hierarchical preference analysis) model developed by the Systems Analysis Laboratory of the Helsinki University of Technology has been used. This model uses the analysis hierarchical process (AHP) technique to evaluate and compare a menu of options. The AHP provides a tool for scoring and weighting of not only quantifiable attributes of a mitigation option/technology, but also integrates ‘non-

Fuel and Energy Abstracts

November 2000

409