Behavior Of Thermal Parameters Research Articles

Simulation Calculation of Spiral Condenser about Refrigerant System

This paper establish a simulation program about the spiral condenser based on theoretical behavior of thermal parameters used R134a as refrigerant, analysis the influence of heat transfer area on refrigerant performance, and calculate best length of condenser heat transfer tube. The results show that the tread of coefficient of performance(COP) and cooling capacity of the system is similar along with the heat transfer tube length, and the research for the optimization design about spiral condenser heat exchanger provides the theoretical support.

Thermal and Textural Properties of Organogels Developed by Candelilla Wax in Safflower Oil

AbstractWe investigated organogel formation in dispersions of CW in safflower oil (SFO). Candelilla wax (CW) has as its main component hentriacontane (78.9%), a n‐alkane with self assembly properties in organic solvents (i.e., vegetable oils). Results showed that, independent of the cooling rate (i.e., 1 °C/min and 10 °C/min) and gel setting temperature (Tset), the CW organogels observed a thermoreversible behavior. This was evaluated by the behavior of thermal parameters that characterized organogel formation (gelation temperature, Tg; heat of gelation, ΔHg) and melting (melting temperature, Tp; heat of melting, ΔHM) after two heating‐cooling cycles. For a given CW concentration (i.e., 0.5, 1.0, and 3%), the magnitude of ΔHM and Tp and the structural organization of the organogel, depended on the cooling rate, the thermodynamic drive force for gelation, and the annealing process occurring at high Tset (i.e., 25 °C). At Tset of 25 °C the microplatelet units that formed the organogel aggregated as a function of storage time, a process that resulted in an increase in organogel hardness. In contrast, at Tset of 5 °C annealing occurred in a limited extent, but gels had higher solid fat content and microplatelet units of a smaller size than the gels obtained at 25 °C. The result was a three‐dimensional network with greater hardness than the one obtained at 25 °C. The 3% CW organogels showed no phase separation up to 3 months at room temperature, with textures of potential use by the food industry.

Static and kinetic thermal properties of ferroelectrics in the phase transition region

Abstract The new data related to thermal properties of ferroelectric crystals in the phase transition region are discussed. Specific heat and heat conductivity coefficient for (NH4)2BeF4, Rb2ZnCl4 and MAPCB crystals are presented and analyzed. The special attention is given to incommensurate phase transitions and possible “overcritical” behavior of thermal parameters.