抽汽供热机组RB控制逻辑优化研究

辅机故障减负荷(RB)控制在机组发生部分主要辅机故障跳闸时,可将机组负荷快速降到当前辅机实际所能达到的相应出力,并调节机组参数至允许范围内,以保障机组持续运行、避免非停事故发生。然而,大量纯凝机组在完成供热或工业供汽改造后,并没有对其RB控制逻辑进行相应修改,导致主要辅机故障时,机组实际负荷仍然低于当前辅机所能达到的相应出力。这进而会导致RB控制拒动,增加了机组非停风险。为了解决上述问题,在分析供汽改造后RB控制逻辑无法触发的原因基础上,首次提出了有效的机组发电负荷实时预测方法。通过采用预测负荷取代机组当前实际负荷,修正了RB控制逻辑触发的判定条件,确保RB控制能够及时正确触发。该方法具有适用广泛、抗干扰性强等优点。

Waste heat water pumping model with direct contact cooling

The performance of a patented water pumping model with steam-air power was presented, which operates automatically by direct contact cooling method. The main objective was to study feasibility of a pumping model for underground water. In this model, a heater installed within the heat tank represented sources of waste heat as energy input for finding appropriate conditions of the 10 L pump model. The system operation had five stages： heating, pumping, vapor flow, cooling, and water suction. The overall water heads of 3, 4.5, 6 and 7.5 m were tested. At the same time, it was found that the pump with 50% air volume is sufficient for pumping water to a desired level. In the experiment, the temperatures in the heating and pumping stages were 100-103 ℃and 80-90 ℃, respectively. The pressure in the pumping stage was 12-18 kPa, and the pressure in the suction stage was about-80 kPa, sufficient for the best performance. It could pump 170 L of water at a 2 m suction head, 120 L at a 3.5 m suction head, 100 L at a 5 m suction head, and 65 L at a 6.5 m suction head in 2 h. A mathematical model for larger pumps was also presented, which operates nearly the same as the present system. Economic analysis of the 10 L pump was also included.

新流行的8款水疗仪

当SPA风日盛时，市面上各式各样，层出不穷的水疗设备多得让人有点头晕目眩，无所适从，这些水疗仪器都有哪些功用？具体如何运用？目前市场最新流行的水疗设备又有哪些呢？这里，有你要找的答案！

Energy and Exergy Analysis of a Novel Efficient Combined Process by Hydrothermal Degradation and Superheated Steam Drying of Degradable Organic Wastes

This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a fraction of dryer thermal energy input can be recovered and used to satisfy the heat requirement in maintaining the HTD operating temperature. Both energy and exergy analysis are applied to the combined process. The analysis covers ranges of dryer inlet temperatures of 202.38-234.19~C and feed water content of 32.5-65%. Thermal energy analysis shows that the combination of HTD and SHS drying can achieve thermal energy self-sufficiency （TES） by manipulating process variables. The exergy analysis indicates the location, type, and magnitude of the exergy losses during the whole process by applying the second law of thermodynamics.

Estimation of clear-sky longwave downward radiation from HJ-1B thermal data

To satisfy the requirement of surface energy budget research on the meso- and micro-scale, a parameterization is developed to calculate high spatial resolution, clear-sky downward longwave radiation （DLR） from HJ-IB thermal data. The DLR algorithm is established based on extensive radiative transfer simulation and statistical analysis. To address the problem that HJ-1B has a single thermal channel and lacks atmospheric information, the brightness temperature of HJ-1B and water vapor content are used in the algorithm. An accuracy evaluation and error analysis for the algorithm is conducted using a simulated radiation da- taset. The result shows that the algorithm performs well in most circumstances, but there is obvious underestimation when wa- ter vapor content is greater than 4 g/cm2. Error analysis indicates the accuracy of estimated DLRs is affected by uncertainties in input parameters, including water vapor content and top-of-atmosphere radiance. It is also affected by the difference between ground and near-surface air temperature. The algorithm is applied to actual HJ-1B data, and validated by ground data from six stations in the Heihe River and Haihe River basins. The estimated DLRs have good consistency with measured data except at Huazhaizi, and root mean square errors at most sites are around 20 W/m2, which is slightly better than the result of MODIS. There is significant overestimation of DLR at Huazhaizi during summer, which is mainly produced by the large ground-air temperature difference. A correction process based on temperature difference is proposed and applied at Huazhaizi. The result shows that the positive bias is largely diminished after correction.

Condenser Optimization in Steam Power Plant

In this paper the effects of the condenser design parameters(such as turbine inlet condition.turbine power and condenser pressure) on heat transfer area,cooling water flow-rate.condenser cost and specific energy generation cost are studied for surface type condenser.The results are given in the text and also shown as diagrams.