جستجوی مقالات مرتبط با کلیدواژه « Pressure Drop » در نشریات گروه « میان رشته ای »

Excessive consumption of energy, particularly fossil fuels has led to the identification of various factors affecting energy consumption in buildings and solutions to reduce consumption. One of the influential indicators of energy consumption in buildings is the time of presence of people, especially in offices. In this research, the effects of a characteristic called DST (change of the official time of the country) and the time of presence of people on the amount of cooling and heating energy consumption were considered. The impact of this indicator was measured in different climates. The selected building was a bank in which the amount of cooling and heating energy consumption was considered in two different modes for the time of presence of people (applying and not applying DST) and keeping other different specifications and details of the building constant in Design Builder software. The results showed that the application of DST in different climates of the country increases the consumption of heating and cooling energy. Non-application of DST causes significant energy savings, especially heating in cities with hot climates such as Ahvaz and Bandar Abbas. In addition, the results of this study indicated that the period of the presence of people, especially in office spaces, was effective in the consumption of heating and cooling energy of the building. Considering the zoning of the climate that exists in Iran, the results of the study indicated that abolishing the change of time would be effective in reducing the consumption of heating and cooling energy.

In this research, the thermal-hydraulic behaviour of fluid in the shell and tube heat exchanger with new segmental perforated baffles and hollow spiral baffles with basic structures (simple segmental and simple helical) were investigated. By using evaluation parameters such as heat transfer, pressure drop, ratio of heat transfer to pressure drop, and efficiency evaluation coefficient (EEC), the effect of the proposed baffles was compared with the basic structure (segmental baffle, single pass helical baffle). Based on the obtained results, the perforated continuous helical baffle reduced the pressure drop by 22.46% compared to the simple helical baffle and the perforated segmental baffle reduced the pressure drop by 19.76% compared to the simple segmental baffle. In a more comprehensive evaluation, the efficiency evaluation coefficient of pore helical and segmental baffle structures showed an increase of 18.3 and 11.17 per cent, respectively compared to the basic configuration. The concept of changing the flow pattern from helix to helix-longitudinal and from zigzag to zigzag-longitudinal made the flow distribution on the shell side more uniform. These conditions reduced areas prone to sedimentation (dead areas) and maintenance costs, and improved system performance. In addition, this new structure can replace conventional segmental baffles to save energy in the long term.