Advanced Materials Research Vols. 960-961

Abstract: To further deepen exploration of boiling in micro-channels a set of experiment system for micro-channel flow boiling is homemade, which includes experimental equipment required and experimental pieces of the design process. The channel is width of 100mm, length of 1200mm, and the groove depth of 95mm. The gasket thickness is 0.5mm, 1.0mm, 1.5mm or 2.0mm.

Abstract: SiO₂–TiO₂ nanocomposite was synthesized by an ultrasound-assisted pure physical method to oxidize elemental mercury (Hg⁰) in simulated flue gas. Due to its low cost and photocatalytic ability, SiO₂ was used to dope TiO₂ to modify the TiO₂ photocatalyst. We put different ratio of TiO₂ / SiO₂ under the UV irradiation to get a low Ti/Si doping ratio and high flue gas mercury removal efficiency of SiO₂–TiO₂ nanocomposite catalyst. It was found that the photocatalytic activity of nanocomposite materials did not significantly improve, or even decline. This is mainly because that the presence of too much porous SiO₂ may affect TiO₂ on the effective absorption of light and direct adsorption of contaminants. When Ti: Si ratio was 2:1, SiO₂–TiO₂ nanocomposite catalyst reached its highest elemental mercury removal efficiency in the simulated flue gas.

Abstract: Gaseous oxidized mercury (Hg²⁺) in the flue gas is soluble in water and can be captured effectively by Wet flue gas desulfurization (WFGD) system. But in some extent Hg⁰ re-emission happens due to the reduction of absorbed Hg²⁺, and the pH of slurry is an important factor affecting Hg⁰ re-emission. In this study, the theoretical formulas of slurry pH were derived through the conventional solution theory and then were used to evaluate the factors determining the pH of slurry. A series of laboratory experiments were carried out under N_2, CO₂ and O₂/N₂ atmosphere to measure the Hg⁰ re-emission tendency at different pH values. The results show that the higher the pH, the less Hg²⁺ reduced by S(IV), resulting in the decrease of Hg⁰ re-emission. Under N₂ atmosphere, the Hg⁰ re-emission was mild at pH>4 while it was dramatic at pH<4. Under O₂/N₂ atmosphere, the addition of O₂ extended the time span of Hg⁰ re-emission at low pH and increased Hg⁰ re-emission unexpectedly in the latter part of the experiments at high pH. CO₂ atmosphere almost did not affect Hg⁰ re-emission because of its little effect on the slurry pH.

Abstract: Experimental study of changing and blending combustion of Shenhua coal on boiler operation was carried out, while the furnace slagging during the experiment, the coal pulverizing system adjustment and the boiler operation oxygen control issues were analyzed. The results show that: the boiler can operate in safety blending Shenhua coal and Zhungeer coal with the ratio of 7:3 based on the strengthening laboratory analysis of coal as fired, the safety and economy of the boiler and coal pulverizing system can be ensured with the pulverized coal fineness R90 in 30%, and selecting the lower mill combinations and setting the coal pulverizer outlet temperature at 73°C, the reasonable exhaust gas oxygen content should be 4.0%, and the boiler thermal efficiency has an 1% increase compared with the condiation of burning inferior Shanxi bituminous coal, the nitrogen oxide emissions are significantly reduced.

Abstract: In order to study the issue of heat imbalance while the ground-source heat pump using in cold regions,this thesis adopts a technology with independent intellectual property rights which is called “thermal compensation control area partition method”.

Abstract: Based on Field Synergy Principle and orthogonal experiment design, nine arranged metal-wire inserts(that is high porosity porous inserts) is determined to experiment. The results showed that heat transfer performance of the pipe that metal-wire inserts is rooted at the core region of pipe is better than the pipe that metal-wire inserts is rooted at the edge region of pipe., location and curve radian can impact heat exchange significantly. Under the given experimental condition, the heat transfer quantity increased by 120 - 520%, overall heat transfer coefficient increased by 126 - 610%. Through enhancing heat transfer performance evaluation criterion (PEC) comprehensive evaluation, it is concluded that when the Reynolds number Re changes in 338 ~ 6931, the PEC value of 0.89 ~ 5.97.The calculation formula of the drag coefficient is obtained by regression analysis.

Abstract: The power economizer of 600MW boiler in ash pipeline system of ash clogging, vibration, resulting in problems of ash conveying device is not running, the causes are analyzed, put forward the optimization scheme. Transformation through a series of Economizer Ash Conveying System, effectively eliminate the ash conveying pipeline vibration, clogging problems, ensure the economizer ash conveying system.

Abstract: Supporting of deep foundation of ditch has become outstanding issues. As a kind of effective supporting measurement, independent development of automatic temperature measuring system and wireless transmission system Foundation ditch and froze soil’s retaining wall has been taken into account. According to study of automatic temperature measurement of foundation ditch and froze soil’s retaining wall and system of wireless transmission, this paper gets its own result. It plays an important role in temperature in foundation ditch and froze soil’s retaining wall and survey in change of froze soil’s retaining wall. And at the same time, we can transfer information and reduce the possibility of damage wire in engineering site. Foundation ditch and froze soil’s retaining wall is a kind of environmental. It has an important meaning in deducing cost of foundation ditch and environmental construction.

Abstract: An intelligent electric heating oil heater control system is designed in this paper. It takes the single chip microcomputer as the core controller; detects environmental temperature using the temperature sensor; controls opening and closing of electric heating oil heater according to the temperature user set; checks whether there is person indoor using the body detection sensor, if there is no, the oil heater is power off automatically; detects environmental humidity using the humidity sensor ,deciding whether the oil heater is turned on according to the current humidity sends out the alarm; detects oil heater placement using the angle sensor for detecting oil heater placement, Unable to start the oil heater. When the electric oil heater stands upside down or is set flat or inclined, it will send out the alarm. At the same time, the system is provided with keyboard and display circuit, which are used to set the various functions, such as setting the child lock and displaying the corresponding information.

Abstract: In this paper, a generalized irreversible heat pump driven by steam turbine cycle model was established by taking account of the heat resistances, heat leak and irreversibility due to the internal dissipation of the working substance. The heat transfer between the heat reservoir and the working substance is assumed to obey the linear (Newtonian) heat transfer law, and the overall heat transfer surface area of the assumed to be constant. The fundamental optimal relations between the heat load, the thermal coefficient of the system and the temperature difference of the evaporator are obtained. Moreover, the effects of the cycle parameters on the characteristics of the cycle are studied by numerical example. The results obtained herein have realistic significance and may provide some theoretical guidance for the performance improvements and optimizations of heat pumps driven by steam turbine.