Abstract— The present article describes a heat exchanger with transparent (smooth) fibres with an atypical body shape and an atypical arrangement of polypropylene capillaries inside. The exchanger cross-section was of a square shape. This type of exchanger was subjected to the investigation of the impact of the fibre arrangement on the overall heat transfer coefficient and behaviour of fibres during the experiment. The exchanger was examined in the counter flow arrangement. The exchanger with 1,400 transparent fibres with the outer diameter of 0.275 mm was examined at the secondary fluid flow rate of 150 l·h-1 to identify the overall heat transfer coefficient k which amounted to 520 W·m-2·K-1. When compared to an exchanger with identical parameters of fibres placed inside a cylindrical exchanger body, a decrease in the overall heat transfer coefficient represented 14%. At the flow rate of 200 l·h-1, the value of the overall heat transfer coefficient identified experimentally was 632 W∙m-2·K-1. When compared to cylindrical exchanger with comparable fibre parameters, the value was 33% lower.
Keywords— Heat exchangers, polypropylene fibres, typical designs Polypropylene Capillary.
Abstract— Due to large resistance and lower reactance of lines, the voltage control and power loss became a crucial issue. The flat voltage profile, is therefore expected to distribution system at each node, minimum power loss, the maximum cost of saving and maximum efficiency. In this context, to find the size and location of compensating devices for the reactive power and voltage control devices became the essential need. In this paper, the multi-objective optimisation problem is solved for the sizing and location of reactive power compensating devices in the distribution system. The main contributions of the proposed work are
- To address the hybrid algorithm to determine the location and size of Distribution Static Synchronous Compensator (D-STATCOM).
- The power loss and voltage deviation are minimised.
- The impact of D-STATCOM with minimum voltage growth is analysed.
The results are verified, tabulated and compared with other methods. The IEEE-33 bus test system has been taken for the analysis.
Keywords— Power loss minimisation, voltage deviation, D-STATCOM.