Abstract. Liquefied natural gas (LNG) contains a large amount of cold energy.The development of cascade utilization of LNG cold energy has large economic benefits, and it is beneficial to reduce the cost of LNG. This paper designed a process and simulated the utilization system of LNG cold energy based on the software Aspen plusin order to utilize the cold energy reasonable. The simulation results show that the cascade utilization system is rationalwhich unites the process of cryogenic comminution of waste rubber, production of liquid CO 2 and dryice, and cold storage. The cascade utilization of LNG cold energy increases the utilization efficiency of LNG cold energy greatly, and it can also save energy.

The heat pipe heat exchanger is applied widely with the advantages of low investment, small volume and good effect of heat transfer. To make a full and reasonable use of the heat resource, a heat pipe heat exchanger is introduced in this paper. Numerical simulation of the heat pipe heat exchanger with different wind speeds is carried out by the CFD software FLUENT. The temperature, velocity contours and effects of heat transfer were compared in different wind speed conditions such as 0.02m/s, 0.04m/s, 0.06m/s,0.08mm/s, 0.1m/s and 0.12m/s. The maximum difference of cold and hot air heat flow rate is 5.344W in the air velocity of 0.04m/s. And the results show that rate of heat recovery can reach 52.9% in this model.

Abstract. Heat pipe heat exchanger is one of the widely used equipment in the industrial field with effective heat transfer. Based on the advantages of the numerical simulation software FLUENT, the design and numerical simulation are carried out. Six cases of different ambient temperature have been studied in this paper include summer and winter. Heat recovery rates are not the same in different seasons. For the larger temperature difference between inside and outside, the rate of heat recovery can reach 56.14% in winter.

Abstract. The method of the selective catalytic reduction (SCR) has become one of the most effective applications of NO x removal technology. Most studies focus the side on fixed bed denitrification at low temperature low space velocity experimental condition, while few studies about denitrification at low temperature high space velocity experimental condition. The catalyst, Mn-Ce/AC, has been prepared by impregnation method in this paper. Under the experimental condition of low temperature high space velocity, catalytic activity was researched in fixed bed denitrification reactor and fluidized bed denitrification reactor respectively. Results show that, the catalytic NO removal is 10.5% at 180℃, the space velocity is 100000 -1 , in fixed bed denitrification reactor; while it is 81.3% in fluidized bed denitrification reactor.