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The numerical simulation of the methanol synthesis process by using HT-L pulverized coal gasification is studied in the work. Pulverized coal gasification are simulated by Aspen Plus industrial systems flower software, and the optimum condition can be gained by calculation. The pulverized coal entrained-flow gasifier adopts the minimization method of Gibbs free energy. Under the given conditions of 1500°C and carbon conversion of 99%, when coal flow volume is 3265.87 kg/h and the ratio of air and coal is 4:1, the content of effective gas is maximal, and also the content of effective gas increased with increasing of the pressure.

The performance of the CO2 trans-critical system is affected significantly not only by optimal system pressure but also by instantaneous ambient temperatures. This paper presents the results of a study carried out to elucidate the influence of the source and sink temperatures on the experimental research of a CO2 trans-critical refrigeration and heat pump system which used a new dual expansion valve and a balance CO2 liquid receiver adjustment device. The unit had been fully tested along a multistate experimental study, at various evaporating temperatures and different gas cooler outlet pressures. The results showed that: the source and sink temperatures rose from 15°C to 25°C, trans-critical CO2 systems COPH average increase of 4.4% each 5°C, but COP decrease of 6.8%. The influence of the source temperature on the chilled water outlet temperature which is less than the sink temperature. The effect of the source or sink temperature on the cooling water outlet temperature to average every 5°C to change the range of from 0.7°C to 1.9°C.

This work present the experimental evaluation of the energy performance of trans-critical CO2refrigeration and heat pump systems. The optimal gas cooler pressure and the optimal COP have been analysed from a thermodynamic point of view. The experimental evaluation covers five evaporating levels (-10 to 10°C) and in a wide range of gas cooler outlet pressures (75 to 120bar). It is concluded that: With the the internal heat exchanger (IHX) system compressor power is relatively low, when the high side pressure is over 100bar, and the evaporation temperature is below 0°C. The COP of the system without IHX is slightly higher than the system with the IHX, it is increase about 3% to 5%, when the evaporation temperature is over 5°C.

In this paper, three-dimensional numerical simulation is conducted on the flow and heat transfer process for elliptical tube heat exchanger with rectangular vortex generators and triangular vortex generator by Fluent software, respectively, and the performance for elliptical tube heat exchanger with plate fin is compared. The results show that the Nusselt number increases with the increase in Reynolds number for the inlet velocity range from 1 to 5m/s, friction coefficient decreases with the increase in Reynolds number; at the same Reynolds number, Nusselt number for fin with Vortex Generators and friction coefficient are higher than that of elliptical tube with plate fin ; the vortex generator shape and angle of attack have a great impact on the comprehensive performance within a simulated attack angle and the velocity, at the same pump power, the comprehensive performance for heat exchanger with the rectangular vortex generator increase up to 10%.