No abstract

The form of transportation of energy from the sources to the consumers is the concern of the researchers across the world, this is due to the consequences upon the failures. Some of these failures causing economical losses and environmental damages. Both are worth to be investigated and studied to reduce the risks and losses. In this paper the effects of cracks in pipelines has been investigated, it is found that the crack is causing the decrease in pressure. Several pipes were used in the experiment, one without crack and the rest with different crack size. The pressure drop in the area around the crack (named crack zone) was bigger in the up and down stream zones. Computational fluid dynamics CFD package ANSIS (Fluent) was used in the analysis and the results presented. Because the fluid used in the research is crude oil, so the paper is mainly for the benefit of the oil and gas industries and the pipeline designers and manufacturers.

The principle of solar chimney power plant (SCPP) is based on harvesting the thermal spectrum of solar radiation and converting it to mechanical energy by the means of a collector, a wind turbine, and a chimney. In this work, a number of experiments were performed on a modified model made up of one-third of the circular collector area. Field data from selected clear, sunny days were recorded and studied. The analysis focused on time-temperature relations for ambient, near chimney entry point and the collector periphery, in addition to hourly solar radiation intensity and air velocity inside the chimney. The results show that for this geometry arrangement, the maximum temperature of the air entering the chimney is achieved before the ambient temperature reaches its peak value. Air velocity inside the chimney depends on the intensity of solar radiation and the temperature difference between the air temperature entering the chimney and the ambient temperature. Solar intensity directly affects the temperature of air beneath the collector, and a part of this energy is stored in the ground. Later, when the solar radiation is impaired, the stored energy can be utilized. Air velocity of 2.1 m/s is obtained after the solar noon, when the solar intensity is 737 W/m2 and the maximum temperature difference is 11.2 °C. Due to the unique geometrical shape of the rig, a minor temperature loss of up to 1.3 °C occurs for the air near the center of the chimney.