ANALISIS EFEKTIVITAS PENUKAR KALOR PIPA HELIKAL DESTILASI MINYAK ATSIRI KAYU PUTIH

The Eucalyptus plant is one of the essential oil-producing plants. Eucalyptus oil processing generally uses the distillation method. Traditionally used eucalyptus oil distillation uses a straight pipe condenser. The weakness of the straight pipe condenser is that the temperature of the condensate that comes out is still very high, this shows that the effectiveness of the straight pipe condenser is not optimal. To optimize the effectiveness of the distillation system condenser, a condenser with a helical pipe type condenser is designed in the essential oil distillation system. This study will vary the ratio of the pitch distance to the diameter of the condenser pipe, which aims to obtain an effective helical coil pitch ratio to optimize the effectiveness of the helical pipe condenser. This study uses the simulation method on COMSOL Multiphysics 5.4. The pitch ratio variant used is 2.1; 2.62; 3.15; 3.67; 4.2. The parameters that are constant in this study are the inlet fluid temperature on the tube side 373 K, the inlet fluid temperature on the shell side 288 K, the fluid inlet velocity on the tube side 0.2 m/s, and the fluid inlet velocity on the shell side 1 m/s. The results of the simulation by varying the pitch ratio show that the effectiveness increases as the pitch ratio value decreases, where the highest effectiveness is shown at pitch ratio of 2.1 which 75.9% and the lowest effectiveness is shown to pitch ratio of 4.2 which 70.7%.

Earth Air Tunnel Heat Exchanger for Building Cooling and Heating

The computational fluid dynamic (CFD) is an influential method for measuring Heat transfer profiles for typical meteorological years. CFD codes are managed by numerical algorithms that may undertake fluid glide headaches. CFD offers the numerical results of partial differential equations with main airflow and heat transfer in a discretized association. The complex fluid glide and the warmth transfer publications worried in any heat exchanger can be determined with the help of the CFD software program (Ansys Fluent). A study states and framework which implicitly rely on the computational fluid dynamics, which is being formulated for computing the efficiency-related parameters of the thermal part and the capability of the EATHE system for cooling. A CFD simulation program is being used for modeling the system. The framework is being validated with the help of the simulation set-up. A thermal model was developed to analyze thermal energy accumulated in soil/ground for the purpose of room cooling/heating of buildings in the desert (hot and dry) climate of the Bikaner region. In this study, the optimization of EATHE design has been performed for finding the thermal performance of straight, spiral, and helical pipe earth air tunnel heat exchanger and Heat transfer rate for helical pipe was found maximum among all designs.

Storing Energy from External Power Supplies Using Phase Change Materials and Various Pipe Configurations

Phase change materials are commonly used for energy storage. Heat transfer enhancement and heat storage are the two main goals in this paper. A cylindrical pipe covered with phase change material is investigated numerically. Ideally, a high temperature liquid flows through the pipe, resulting in heat transferred to the phase change material. To enhance the heat transfer, various configurations involving the addition of a twisted tape inside of the pipe and the use of helical shape pipes were investigated. A straight pipe with no twisted tape insert was also analyzed and used as a benchmark case. All the configurations had constant properties such as material selection, overall size, pipe diameter and inlet Reynold’s number, so the performance could be compared under similar conditions. All initial configurations were simulated and the heat transfer rate, Nusselt number, friction factor and performance evaluation criterion (PEC) of the designs were determined. It was found that the heat transfer rate and Nusselt number of all the various designs yielded higher results than the reference straight pipe configuration. Additionally, due to the added complexity in the flow caused by the insert, the friction factor of all the configurations was also higher. The helical pipe configuration was the only configuration that had a PEC higher than that of the reference straight pipe. This is because the negative impacts caused by the friction factor outweighed the gains in Nusselt number for the twisted tape designs. It was also hypothesized that lowering the inner diameter of the helical pipe would increase the PEC. Further simulations with modified inner diameters were done to test the hypothesis. The simulations confirmed the hypothesis, as the pipes with inner diameters 0.75 and 0.5 cm led to a 50% and 150% increase in the PEC respectively, when compared to an inner diameter of 1 cm. It was also determined that smaller inner diameters led to lower outlet temperatures meaning a higher percentage of the thermal energy from the fluid was transferred to the phase change material.

Numerical Study of Turbulent Convective Heat Transfer of Aviation Kerosene in Coiled Pipes

Turbulent flow and convective heat transfer of kerosene in helical pipes with different wall thermal conditions and curvature radii of pipe were numerically studied with Reynolds Averaged Numerical Method and realizable k-e turbulence model. The fluid media is aviation kerosene with an inlet supercritical pressure of 3MPa and an inlet temperature of 400K. The present results provide temperature and velocity fields as well as distributions of turbulence kinetic energy and streamlines at different axial locations along the flow direction. The non-dimensional heat transfer coefficient, Nusselt number at the inner and the outer sides of the pipe wall are compared and its value of the outer side is higher than that of inner side by 75%. Compared to straight pipe with the same pipe radius of 6mm and inlet flow conditions, the helical pipe with a curvature radius of 192.5mm can increase the averaged heat transfer coefficient by 28.5%. Meanwhile, it is found that when the curvature ratio increases, the effect of secondary flow in helical pipe is more significant and the difference of heat transfer between different locations of the pipe wall is larger. In addition, the present results also reveal that heat transfer deterioration takes place for the kerosene flow in helical pipe with an increased wall heat flux due to the state change of kerosene from liquid to supercritical.