A review of cryogenic power generation cycles with liquefied natural gas cold energy utilization

Liquefied natural gas （LNG）, an increasingly widely applied clean fuel, releases a large number of cold energy in its regasification process. In the present paper, the existing power generation cycles utilizing LNG cold energy are introduced and summarized. The direction of cycle improvement can be divided into the key factors affecting basic power generation cycles and the structural enhancement of cycles utilizing LNG cold energy. The former includes the effects of LNG-side parameters, working fluids, and inlet and outlet thermodynamic parameters of equipment, while the latter is based on Rankine cycle, Brayton cycle, Kalina cycle and their compound cycles. In the present paper, the diversities of cryogenic power generation cycles utilizing LNG cold energy are discussed and analyzed. It is pointed out that further researches should focus on the selection and component matching of organic mixed working fluids and the combination of process simulation and experi- mental investigation, etc.

Study on the Complex Prescription Compatibility Law of the Cold and Hot Nature of Mahuang Decoction(麻黄汤) and Its Categorized Formulae Based on the Cold-Hot Pad Differentiating Assay

Objective：To explore the complex prescription compatibility law of the cold and hot nature of Mahuang Decoction（麻黄汤,MHD） and Maxing Shigan Decoction（麻杏石甘汤,MXSGD）,both categorized formulas but with different hot/cold natures.Methods：Oxygen consumption of mice was determined among three groups：MHD,MXSGD and the control;a cold-hot pad differentiating assay was used to observe the variability of temperature tropism among the groups of mice which was treated with MHD,MXSGD,and their compositions. Meanwhile,the total anti-oxidant capability（T-AOC） activity were detected.Results：After administration of MHD, the mice showed increased oxygen consumption（P0.01）.Compared with MHD group,the remaining rate of MXSGD mice on the hot pad was found to be significantly increased with the cold-hot pad differentiating assay （P0.05）.There was no significant difference（P0.05） among the remaining rates of MXSGD,MXSGD with high dose Gypsum Fibrosum（MXHGF） group,and MXSGD with low dose Gypsum Fibrosum（MXLGF） group mice.Compared with the MHD group,T-AOC activity of the mice in the Consensus Compositons group was significantly decreased（P=0.0494）.Compared with the MXSGD group,T-AOC activity of Gypsum Fibrosum （GF） group was increased significantly（P=0.0013）.Conclusions：The differences in cold and hot nature could be represented objectively between MHD with a hot nature and MXSGD with a cold nature.The reason may be the Gypsum Fibrosum which decreased the efficacy of the consensus compositions.However,increasing or decreasing the dose of Gypsum Fibrosum will not change the cold and hot nature of MXSGD.

Different Effects of Mahuang Decoction and Maxing Shigan Decoction on Animal Temperature Tropism and Correlation to Differences of Cold and Hot Nature of Chinese Materia Medica

Objective To establish an objective method for evaluating the intrinsic characteristics between cold and hot nature of Chinese materia medica (CMM) through the different effects of Mahuang decoction (MHD) and Maxing Shigan decoction (MSD) on animal temperature tropism. Methods The equipment with cold/hot pads was used to investigate the variety of the temperature tropism between two groups of mice treated by MHD and MSD, respectively. Meanwhile, the activities of adenosine triphosphatase (ATPase), superoxide dismutase, succinate dehydrogenase, and malondialdehyde were measured. Results After treated by MHD, the macroscopic behavioral index of remaining rate on warm pad (40 ℃ ) of mice decreased significantly (P < 0.05), suggesting the enhancement of cold tropism, meanwhile, the internal indices of ATPase activity and oxygen consuming volume increased significantly (P < 0.05), suggesting the enhancement of energy metabolism. On the other hand, the above-mentioned indices in MSD group changed on the inverse way. Conclusion The relative drug nature of MHD and MSD revealed in this study is consistent with the theoretical prognostication or definition. It indicates that the internal cold and hot nature of CMM could be reflected in ethological way on the changes of animal temperature tropism which might be internally regulated by body energy metabolism.