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Due to the low boiling point of organic fluids, the organic Rankine cycle (ORC) is an effective way to improve the recovery efficiency of low-temperature waste heat. An ORC power plant was established with an actual generating capacity of 16.3 kW. As the ORC technology is in the initial stage of commercial application, a technical and economic analysis has been conducted in this paper. Through analysis of each part investment of the power generation plant, it is found that the ORC system part accounts for 61% of the total initial investment, and the larger the power generation scale, the larger the proportion. An economic model has been proposed to study the economic feasibility of low-temperature industrial waste heat conversion in this plant. The influences of the installation of cooling water system, preheater, superheater, loan ratio, interest rate on electricity production cost (EPC) and profit are analyzed. According to the analysis, the lowest EPC of the plant is 0.46 Yuan/(kW • h).

The condensation heat transfer coefficient of R134a was experimentally studied inside two smooth and four micro-fin tubes. The working conditions and structural parameters of the test tubes were selected as the influencing factors, and the experiment was conducted under mass velocities of 400–1100 kg·m−2·s−1, condensation temperatures of 35–45 °C and water-testing Reynolds numbers of 8000–22,000, with an inlet superheat of 1–2 °C and outlet subcooling of 1–2 °C at the test section for the refrigerant. Experimental results indicate that the heat transfer coefficient increases with increasing mass velocity and decreasing condensation temperature and water-testing Reynolds number. The heat transfer coefficient of the micro-fin tube with a helix angle of 28° is the highest and that of smooth tube is the lowest for test tubes with the same inner diameter. Tube diameter has a small influence on the heat transfer coefficient for the smooth tubes while the heat transfer coefficient increases with decreasing tube diameter for the micro-fin tubes. The heat transfer coefficient inside the test tube was compared with some well-known existing correlations, and results show that correlations by Cavallini et al., Thome et al., Shah and Akers et al. can estimate the experimental data with mean absolute deviation of less than 30%, and correlations of Dobson and Chato et al. and Jung et al. cannot be used to capture the heat transfer coefficient with mean absolute deviations of 140.18% and 146.23%, respectively. While the Miyara et al. correlation overestimates the heat transfer coefficient, correlations of Cavallini et al., Koyama et al. and Oliver et al. all underestimate the experimental data for the micro-fin tube. Their deviations are from 25 to 55% for micro-fin tubes 3 and 4, while their deviations keep to within 30% for micro-fin tubes 5 and 6. Finally, to improve the correlation prediction accuracy, a dimensionless parameter was introduced to the correlations of Dobson and Chato et al. and Jung et al., and correlations of Cavallini et al., Koyama et al. and Oliver et al. were modified by enhancing the turbulence effect. The prediction accuracy of all modified correlations can be controlled to within 30%.

Background Vascular dementia (VD) is a syndrome or diagnosis that has different causes and clinical manifestations relating to several different vascular mechanisms and changes in the brain. Some traditional Chinese herbal medicines were developed for treating VD. DH: Yizhi capsule is one such herbal concoction which is reported to improve clinical symptoms significantly. The efficacy and adverse effects of Yizhi capsule need to be reviewed systematically and assessed critically to inform clinical practice and guide the continued search for new treatment regimens. Objectives To assess the effectiveness and possible adverse events of 'Yizhi capsule' in treating vascular dementia. Search strategy The Cochrane Dementia and Cognitive Improvement Group's Specialised Register was searched on 18 September 2006 using the terms yi-zhi, "yi zhi" and yizhi. This database contains trial references from major health care databases and ongoing trial database and is up to date. In addition the review authors searched a variety of Chinese databases. Selection criteria Randomised, placebo controlled trials in which patients with vascular dementia were treated with 'Yizhi capsule' were included. Data collection and analysis Two authors independently assessed trial quality and extracted data. We telephoned study authors for missing information as to whether treatment allocation was randomised and other methodological details. Main results No studies were found that met the inclusion criteria. We identified nine references to trials which included the term 'Yizhi capsule' in the description of the interventions. Two study authors were contacted by telephone and we discovered that the allocation methods they had used were not actually randomised. Four references were describing the same study. Three studies were excluded because 'positive drugs' were used as a control. Authors' conclusions There is no evidence from randomised controlled trials to support or proscribe against the use of 'Yizhi capsule' as a treatment for vascular dementia.