The Effect of Windscreens and Walkways On Air-cooled Condenser Performance and Fan Blade Dynamic Loading

This paper presents a relative comparison of the impact of cruciform screens, perimeter screens and walkways on 3 × 6 cell forced draft air-cooled condenser's (ACC) thermal performance and dynamic fan blade loading under windy conditions. Numerical simulations were carried out for the three mitigation measures at two fan platform heights, four wind speeds and three wind directions. The results indicate that walkways are a robust solution to ACC wind effects and offer benefits in terms of thermal performance and dynamic blade loading under all wind conditions considered. Cruciform screens offered the most effective mitigation of wind-related thermal performance deterioration under certain wind conditions, but the impact of these screens is sensitive to the wind direction. The dynamic blade loading impact of cruciform screens is variable, and these screens are not recommended for dynamic blade loading mitigation. Perimeter screens offered the most effective mitigation of dynamic blade loading and were particularly effective at high wind speeds but often exacted a penalty in terms of thermal performance at moderate to low wind speeds. The results of this study indicate that a correctly configured wind mitigation system, potentially consisting of more than one individual mechanism, could help improve thermal performance and simultaneously reduce dynamic blade loading under windy conditions resulting in a robust, wind resistant condenser.

Effect Of The Water Inlet Temperature And Flow Rate On The Energy And Exergy Performance of A Forced Draft Counter Wet Cooling Tower

Cooling towers, wherein water and air are contacted directly with each other, are specialized heat exchangers. These open-topped, tall, cubical or cylindrical shaped are responsible for reducing the temperature of the water that generated from the industrial or HVAC systems. The performance of the forced draft wet cooling tower is investigated experimentally. The performance analysis is based on the first and second law of thermodynamics. The impact of the inlet water temperature and water inlet flow rate is investigated. The inlet water temperature is varied from 28 °C to 42 °C for the water flow rates of (0.03, 0.05 and 0.075 kg/sec). The results reveal that the cooling capacity, cooling range, thermal efficiency and the total exergy destruction increase according to the increase in the inlet water temperature and the water flow rate. The maximum cooling range is found to be 14.8 °C with the maximum thermal efficiency of 74 %. On other hand, the exergy efficiency decreases with the increasing of the inlet water temperature and the water flow rate within a range of 11.9 % to 57.8 %.

Design, Fabrication and Testing of a Forced Draft Biomass Cook Stove

An approach towards an Improvement in performance of cook stoves has been a great challenge to scientists and researchers as biomass cook stoves are one of the basic needs of people living in rural areas. But due to household pollution by Traditional Cook stoves causes illness to people preparing for their regular meals near it. So, taking an initiative for Designing, Fabricating and Improvisation in the performance of Forced Draft cook stoves by placing proper Primary and Secondary holes in combustion chamber which gives better air distribution for proper combustion to get Lower Emission rates. Various experimentations are being performed on the basis of standard protocols i.e. BIS (Bureau of Indian Standards), VITA (Volunteer in Technical Assistance), EPTP (Emission Performance Test Protocol), WBT (Water Boiling Test) amongst which BIS had an upper hand and had very less uncertainty of errors due to which it is mostly being used in checking and improving emission performance of cook stoves for more efficient use with less chances of health issues. This paper consists of Design, Calculations and Constructional working of Forced Draft Biomass Cook stove and also the Burning rate Calculations were carried out to check fuel burnt rate.

Investigation of Different Laboratory Aging Methods of Bituminous Mixtures

The predicted performance and service life of the pavement depend largely on the properties of bitumen used in the mixtures. The most important feature of bitumen, which has profound effect on the performance of the road is durability. The durability of bitumen is expressed as the resistance to aging. In this study, the bituminous mixture aging was performed instead of bitumen aging in order to represent the aging in the field in the best possible way. The aim of this paper is to evaluate different proposed laboratory aging methods (NCHRP 09-52, NCHRP 09-54 and RILEM) in relation with the current Standard AASHTO R30 (Standard Practice For Mixture Conditioning of Hot Mix Asphalt standard) and to make comparison with the samples performance taken from the field in terms of Indirect Tensile Strength (ITS). The level of aging has also been compared with the samples taken from recently constructed pavement surface and from the five years old pavement surface. Results depicted that, laboratory aging methods revealed the field aging properties on the unaged bitumen. Based on the results, 2 hours forced draft oven aging at 135°C is recommended as short term aging condition because, 2 hours or 4 hours short term forced draft oven aging did not yield significant variation in terms of ITS values. Additionally, 120 hours (5 days) oven aging of compacted samples at 85°C can be recommended as long term aging condition.