Review on an Advanced Combustion Technology: Supercritical Hydrothermal Combustion

Abstract

Supercritical hydrothermal combustion, a new and promising homogeneous combustion technology with a wide range of application scenarios and broad development prospects, provides creative ideas and means for the enhanced degradation of organic wastes, hydrothermal spallation drilling, thermal recovery of heavy oil, etc. This technology is elaborated upon in five parts: (1) introducing the main devices including semi-batch reactor and continuous reactor to study the hydrothermal flame in accordance with research institutions, (2) presenting the research status of related numerical simulation from the angles of reaction kinetics and flow-reaction, (3) summarizing the characteristics of hydrothermal flame and combustion by five key parameters, (4) dividing up ignition process and explaining ignition mechanism from the perspectives of critical physical properties of water and heat transfer and mixing conditions, (5) discussing and forecasting its industrial applications including hydrothermal spallation drilling, the thermal recovery of heavy oil, the clean conversion and utilization of coal-based fuel, and the harmless treatment of pollutants. By and large, this paper analyzed in detail everything from experimental equipment to industrial applications, from combustion characteristics to ignition mechanisms, and from summary conclusions to prospect prediction. In the end, herein is summarized a couple of existing paramount scientific and technical obstacles in hydrothermal combustion. Further significant studies in the future should include excellent reactors, advanced monitoring techniques, and powerful computational fluid dynamics.

Comparative Numerical Aerodynamics Performance Analysis of NACA0015 and NACA4415 Airfoils

“…(5) (6) To obtain the normal and axial force, the interpolated and extrapolated pressure coefficients will be applied to the Eq. ( 7) and Eq.…”

“…Airfoil profiles are designed asymmetrically to create aerodynamic force while moving in the air. It is aimed to create a pressure difference between the upper surface and the lower surface of the airfoil [6] [7] [8]. By giving the angle of attack to the airfoils used in wind turbines, the lifting force can be increased, and indirectly the aerodynamic efficiency will be increased [9].…”

Effect of the Fuel Equivalence Ratio on the Mechanisms of Thiophene Oxidation in Water Vapor at Increased Density of the Reagents

“…Depletion of light oil reserves and increased consumption of motor fuels lead to the involvement in the processing of heavy oil raw materials (heavy oil, bitumen, tar, and oil shale), characterized by a high content of thiophene derivatives. − The accumulation of waste from the production and processing of such raw materials causes environmental problems, in particular, pollution of nearby water areas. , Incineration of these wastes by conventional methods leads to the release of SO 2 and aerosol particles (primarily soot) into the atmosphere. , Since these wastes are usually waterlogged, the use of high-density water vapor or supercritical water (SCW: T > 647 K, P > 22.1 MPa) can become one of the ways of their environmentally safe processing. , The latter, in particular, is determined by the fact that the final product of oxidation of S-containing organic substances in an aqueous-oxygen mixture is sulfuric acid. , It is obvious that for the development of new technologies based on the combustion of fuels and wastes in dense water vapor or SCW, it is necessary to obtain data on the oxidation features of the individual compounds in these media. Oxidation of several hydrocarbons and heteroatomic compounds was studied earlier. − The present research is aimed at identifying the features of thiophene oxidation, as the simplest aromatic S-containing compound, in an aqueous medium.…”

“…7,8 Since these wastes are usually waterlogged, the use of high-density water vapor or supercritical water (SCW: T > 647 K, P > 22.1 MPa) can become one of the ways of their environmentally safe processing. 9,10 The latter, in particular, is determined by the fact that the final product of oxidation of S-containing organic substances in an aqueousoxygen mixture is sulfuric acid. 11,12 It is obvious that for the development of new technologies based on the combustion of fuels and wastes in dense water vapor or SCW, it is necessary to obtain data on the oxidation features of the individual compounds in these media.…”

“…Figure 9. Schematic sketch of the test facility: reactor (1); twochannel corundum tube (2); thermocouple inserted into the reactor (T in ); measuring thermocouples (T 1 , T 3 ); controlling thermocouple (T 2 ); sealing copper gasket (3); a cell with CaCO 3 (4); capillary for the input of reagent (5); adjusting valve (6); rubber membrane for the input of liquid reagent(7); shut-off valve (8); strain gauge transducer (9); indicator communicator to pressure sensor(10).…”