Efficiency Of Vortex Tube Research Articles

Performance analysis of vortex tube-thermoelectric system in gas stations

At natural gas pressure reducing stations, gas first enters a water bath heater to boost its temperature slightly, and after leaving the heater, it enters the throttle valve to reduce its pressure. This method has two major drawbacks, which are the consumption of natural gas in the heater and the excessive loss of exergy in the throttle valve. The pressure of natural gas can be reduced by using a vortex tube and converting it into hot and cold currents, and then generating electricity by directing these currents to thermoelectric generators (TEGs). Investigation of energy, exergy and environmental performance of the hybrid vortex tube-TEG system and optimization of its performance for the working condition of Kermanshah pressure reducing station is the subject of the present study. The cold mass fraction (CF) and efficiency of vortex tube are considered as decision variables. Moreover, annual average first-law efficiency (ηI-TEG), annual average second-law efficiency (ηII-TEG) and annual total electric power generated by the TEGs (Pout) are considered as optimization target functions. The results of genetic algorithm based three-objective optimization revealed that the specifications of the optimal system are: vortex tube efficiency = 0.36967, CF=0.95598, ηI-TEG=0.03442, ηII-TEG=0.04544, Pout=42770.58 kW and amount of CO2 mitigation per annum = 8.55 tons.

Investigation on the Changes in the Temperature that is Caused in Vortex Tube

This paper presents effect of cold mass friction, the rates of air flow, the inlet pressure, and the time on hot and cold air temperatures that are generated in the vortex tube. The vortex tube is manufactured by simple equip-ments within low prices. That proves the simplification of the vortex tube. Although the efficiency of vortex tube is low, but it produces low temperatures without using expensive cooling machines.

Improving vortex tube performance based on vortex generator design

The effect of vortex generator parameters (Cold orifice angle, Cold orifice diameter and Nozzle area) on vortex tube performance is investigated experimentally. Vortex tube is connected to a natural gas pipeline with constant pressure of 4 bars. To improve vortex tube efficiency, six generators with different cold orifice angle, five generators with different cold orifice diameter and three generators with different nozzle area are studied for each experiment part. Results show variation of nozzle area has no effect on optimum cold mass fraction while cold mass angle and cold mass diameter move this point. Increment in cold orifice diameter increases optimum cold mass fraction and decreases cold temperature. As the angle of cold orifice increases, more mass flow passes through cold outlet and optimum cold mass fraction also increases. The expansion of the gas in the diffuser type cold orifice is investigated as the dominating reason for the different vortex tube performance. These mentioned designing parameters of vortex generator affect the flow pattern and efficiency of vortex tube as a consequence. For cold orifice angle of 4.1°, cold orifice ratio of 0.64 and nozzle area ratio of 0.14, highest efficiency is achieved.