EXPERIMENTAL RESEARCH INSIDE A GAS HEATER WITH DIFFERENT INTERMEDIATE HEAT CARRIER MEDIUM
The gas heater is one of the key equipments in gas industry, which plays the role of heating natural gas to the required processing temperature, and the application of gas heater shows a promising prospect. The cylindertype heating device with an intermediate heat carrier medium is most widely employed. Apparently, the selection of intermediate heat carrier medium and the form of heat transfer process of the intermediate heat carrier medium, i.e. the flow field organization in the large capacity cylinder, is the key elements that greatly affect the thermal efficiency of gas heater. A real gas heater experimental system, which is the only one in China, is built. The present paper characterizes water and ethylene glycol as the intermediate heat carrier medium. Experimental measurements and analysis on the flow condition and temperature distribution between the water and ethylene glycol in the cylinder were carried out. The results shown that using ethylene glycol as the heat carrier media can widen the application range of gas heater. The efficiency of the heater with ethylene glycol as the heat carrier medium is at least 3.8% higher than that with water as the heat carrier medium under the same working conditions. The thermal efficiency of gas heater is usually less than 87%.
Visualized experimental investigation on the natural gas heater
Based on the structure of natural gas heater,a visualized experimental system was designed in,which electrically heated air was employed without fuel combustion process.Experimental investigation and analysis on the flow condition and temperature distribution of the heat-transfer medium were carried out.A simple and effective modified structure was brought forward,the arrangement of the heating and cooling surfaces was optimized,and the heat transfer in the cylinder will be more effective.
Thermal performance analysis of intermediate fluid vaporizer for liquefied natural gas
Abstract The intermediate fluid vaporizer (IFV) is a new kind of vaporizer for liquefied natural gas (LNG). A thermal model was established based on the energy balance among the three typical parts of IFV, namely, evaporator, condenser and thermolator, whose mutual coupling and constraints were fully considered. Calculation codes were developed to solve the energy balance equations, in which the formulation of experimental correlations and thermal property codes were incorporated into the iteration. The temperature, pressure and mass flow rate of the inlet LNG and seawater, as well as the heat transfer area of the three parts, were known parameters. The outlet temperature of natural gas (NG) and seawater, the surface and total heat transfer coefficients in the three parts, and the propane saturation temperature were the solution parameters. The effects of the temperature and mass flow of inlet seawater, the pressure, and mass flow rate of inlet LNG on the solution parameters were systematically investigated. The intrinsic link, in terms of the heat transfer performance inside the IFV, was revealed. The outlet temperature of seawater and NG increased with increased temperature and mass flow rate of the inlet seawater and with reduced inlet mass flow rate of LNG. The increased inlet pressure of LNG significantly improved the NG outlet temperature, but this increment has mild influence on the outlet temperature of seawater. The propane saturation temperature also increased with increased temperature and mass flow rate of inlet seawater and with reduced inlet LNG mass flow rate, whereas, it was not sensitive to the inlet LNG pressure.