Experimental and 3D CFD investigation on heat transfer and energy separation inside a counter flow vortex tube using different shapes of hot control valves

A vortex tube is a mechanical device which provides instant heating and cooling by separating the hot and cold streams via application of compressed working fluid to the orifice nozzles. Due to its energy separation capability researchers tend to make detailed investigations about vortex tubes recently. In order to make an investigation both numerical and experimental, the common accepted way of scientific researches is reviewing previous researches. Therefore, review studies play a vital role on new studies. In accordance with this phenomenon, this paper presents a comprehensive review about the parameters which affect the thermal performance of a RHVT such as working fluid, nozzle number, nozzle material, circuit connection type and cold mass fraction. The main objective of this study is to lead future investigations about vortex tubes having qualified outcomes.

Effects of working fluid, nozzle number, nozzle material and connection type on thermal performance of a Ranque–Hilsch vortex tube: A review

Experimental investigation & CFD analysis of Ranque–Hilsch vortex tube

The flow structure and energy separation considering the effect of cold mass fraction in a Ranque–Hilsch vortex tube were investigated computationally based on the vortex breakdown theory The velocity distributions and pressure fields for nine different cold mass fractions were considered A quasi-cylindrical approximation was adopted to predict the size of the vortex core size by considering the pressure gradient Further, a novel analysis was conducted on the energy separation mechanism, in which the large-scale vortex structure plays an important role; for example, increasing the cold mass fraction within a certain range can result in bigger vortex cores, yielding better energy separation performance Finally, the type of vortex breakdown was also discussed for further understanding the vortex structure This paper offers a new idea on the manner in which the external conditions (here, cold mass fraction) affect the large-scale vortex structure and on the subsequent energy separation performance

Computational investigation of precessing vortex breakdown and energy separation in a Ranque–Hilsch vortex tube

Efficiency evaluation of vortex tube cyclone separator

A vortex tube is a simple-structure device which can separate a compressed stream into a hot and a cold stream The accurate flow pattern inside the vortex tube remains elusive and no satisfactory explanation of its energy separation mechanism has been put forward yet In this work, the influences of inlet pressure and cold mass fraction on the performance of the vortex tube were explored The experimental results show that the static temperature in the center of vortex tube is higher than that of the peripheral part Besides, the stagnation point inside the vortex tube moves to the cold end with the decrease of the inlet pressure or the increase of the cold mass fraction This paper also tries to present an explanation for the maximum cooling effect and the maximum heating effect when the cold mass fraction is about 03 and 08, respectively

Experimental study of the energy separation in a vortex tube

In order to get the internal parameters of a vortex tube, a large-scale vortex tube was designed and an experimental device was built. A five-hole probe and thermocouples were used to obtain the three-dimensional velocities, the static pressure, static temperature and total temperature distributions inside the vortex tube. Four different cold mass fraction conditions (0.2, 0.4, 0.6 and 0.8) were chosen and the impacts on the internal parameters of the vortex tube were discussed. Different from the traditional view, the tangential velocity was considered to be the steady Burgers vortex form. A reverse flow boundary was found, and the location of which was changed at different operation conditions and axial positions. Further, it was found that the lowest static temperature existed near the nozzle outlet, and a new static temperature difference distribution law was firstly proposed experimentally.

Experimental study of the impacts of cold mass fraction on internal parameters of a vortex tube

The invention discloses a portable cold-hot dual-purpose electric fan based on vortex tubes. The electric fan comprises a fan, a gas compression device, an electric motor used for driving the fan andthe gas compression device, and a vortex tube device connected with the gas compression device, wherein the gas compression device generates high-pressure gas under the driving of the electric motor and the high-pressure gas enters the vortex tube device; and the vortex tube device converts the high-pressure gas into a cold gas flow and a hot gas flow, and the fan drives and diffuses the cold gasflow to a space requiring cooling or drives and diffuses the hot gas flow to a space requiring heating. The electric fan can simultaneously generate cold air and hot air, and has the characteristics of being simple in structure and convenient to carry.

Portable cold-hot dual-purpose electric fan based on vortex tubes

The invention discloses a refrigeration and heating device based on a vortex tube. The refrigeration and heating device based on the vortex tube is characterized by comprising a drive device, a gas compression device and a vortex tube device, wherein the drive device drives the gas compression device to generate high-pressure gas and enabling the high-pressure gas to enter into the vortex tube device; the vortex tube device converts the high-pressure gas to cold gas flow and hot gas flow; and the drive device is a hand rocker or a fan blade. The refrigeration and heating device does not dependon energy supply of an environment, and refrigeration and heating effects can be generated in a tent only by manual mechanical drive or by virtue of wind energy; and the refrigeration and heating device has the characteristics of being simple in structure, convenient to carry, and the like, and suitable for being applied to camping in the wild without power supply provision and abundant wind power resources.

Li Nian

Papers

Experimental study of the energy separation in a vortex tube

Experimental study of the impacts of cold mass fraction on internal parameters of a vortex tube

Portable cold-hot dual-purpose electric fan based on vortex tubes

Refrigeration and heating device based on vortex tube