Research and analysis of heating efficiency and pollution emission based on heat dissipation of building walls

2021 ◽  
Author(s):  
Kuo Meng ◽  
Zhengxing He ◽  
Haiyi Sun
Keyword(s):  
Heat Dissipation ◽  
Heating Efficiency ◽  
Pollution Emission ◽  
Building Walls

Application Self-Regulating Heating Cable Curing of Concrete in Winter

2014 ◽  
Vol 638-640 ◽  
pp. 1531-1535 ◽  
Author(s):  
Jin Bao Guo ◽  
Lin Liu ◽  
Qiang Wang
Keyword(s):  
Heat Dissipation ◽  
Heating Temperature ◽  
Heating Time ◽  
Minimum Length ◽  
It Use ◽  
Heating Efficiency ◽  
Cable Length ◽  
Heating Cable ◽  
Curing Methods ◽  
Two Parameters

In order to solve the shortcomings of traditional methods of concrete curing in winter, proposed self-regulating heating cable new concrete curing methods. Several aspects were considered, about the heating cable length and heating time, heating temperature. According to energy conservation, heating and heat dissipation balance, derived formulas of heating cable normal use length and minimum. As conclusions is shown, first, the normal length design can controlled better heating temperature, it use the cable length and heating time, heating temperature two parameters to control the other parameters. Second, it is better heating efficiency, can be the overall warming state quickly. In addition, when the concrete pouring temperature is above 10 °C, it is not need additional heating, and it can choose minimum length design formula.

scholarly journals Experimental Study on Thermal Performance of Externally Insulated Walls of Intermittent Air-Conditioned Rooms in Summer in Hot Summer and Cold Winter Region, China

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Yong Ding ◽  
Lu Xu ◽  
Baizhan Li ◽  
Xiaoqing Liu
Keyword(s):  
Heat Flux ◽  
Thermal Performance ◽  
Thermal Process ◽  
Heat Dissipation ◽  
Distribution Characteristics ◽  
Cold Winter ◽  
Night Time ◽  
Heat Transfer Theory ◽  
Heat Preservation ◽  
Building Walls

Now requirements for the thermal performance of building walls are based on the assumption that heat flux transfers in one direction through the wall. However, in Hot Summer and Cold Winter Region of China, the direction of heat flow in the wall not only changes with the seasons, but also changes in the same period of using. In this paper, dynamic thermal process of externally insulated walls in different air-conditioner’s running state in summer in Chongqing, China, was tested. The distribution characteristics of the outdoor and indoor air temperature and the surface and inner temperatures of the wall were analyzed and demonstrated. Based on the unsteady-state heat transfer theory, the study calculated and analyzed the distribution characteristics of the direction of the heat flux in the thermal process. Also the characteristics of insulation and heat preservation for walls under different air-conditioner’s running state were analyzed. It is shown that, in any air-conditioner’s running state, the direction of the heat flux through the wall is obviously dynamically changing. There is obvious difference in the thermal performance needs of the wall; that is, it has strong demand for thermal insulation in daytime and strong demand for heat dissipation during night time in summer.

Deep Drawing and Bulging Processes of Hard-Deformed Light Alloy Sheet with Resistance Heating

2014 ◽  
Vol 541-542 ◽  
pp. 268-272
Author(s):  
Zhan Jiao Gao ◽  
Kai Feng Zhang ◽  
Bo Wang ◽  
Chao Li
Keyword(s):  
Magnesium Alloy ◽  
Deep Drawing ◽  
Heat Dissipation ◽  
Pulse Current ◽  
Dimensional Accuracy ◽  
Alloy Sheet ◽  
Resistance Heating ◽  
Aluminium Matrix Composite ◽  
Heating Efficiency ◽  
Deformation Properties

For enhance the heating efficiency and the formability of the magnesium alloy and aluminium matrix composite sheets, pulse current is adopted to the gas bulging and stamping processes. During the bulging process of magnesium alloy sheet, the effects of dynamic pulse current on the formed sheet combine both thermoelectricity and electro-plasticity. The effect and the applicability of the pulse current heating have been evaluated. The deformation properties, microstructure characteristics, and dislocation movement of the AZ31 alloy sheet during bulging process by the resistance heating are investigated. And the resistance heating has been adopted to improve the formability of SiCp/2024Al composites in stamping process. The pulse current density achieved 21.7A/mm2and temperature of SiCp/2024Al composite correspondingly reached to around 400°C in the 50s. The results showed that stainless steel inserts between sheet and copper electrodes successfully prevented the heat dissipation and promote temperature uniformity over the sheet during electrifying. In addition, workpiece formed by the pulse current deep drawing shows better shape retention, surface quality and high geometry dimensional accuracy.

scholarly journals Maghemite (γ-Fe2O3) and γ-Fe2O3-TiO2 Nanoparticles for Magnetic Hyperthermia Applications: Synthesis, Characterization and Heating Efficiency

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5691
Author(s):  
O. M. Lemine ◽  
Nawal Madkhali ◽  
Marzook Alshammari ◽  
Saja Algessair ◽  
Abbasher Gismelseed ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Heat Dissipation ◽  
Wide Spectrum ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Magnetic Hyperthermia ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Heating Efficiency ◽  
High Heating

In this report, the heating efficiencies of γ-Fe2O3 and hybrid γ-Fe2O3-TiO2 nanoparticles NPs under an alternating magnetic field (AMF) have been investigated to evaluate their feasible use in magnetic hyperthermia. The NPs were synthesized by a modified sol-gel method and characterized by different techniques. X-ray diffraction (XRD), Mössbauer spectroscopy and electron microscopy analyses confirmed the maghemite (γ-Fe2O3) phase, crystallinity, good uniformity and 10 nm core sizes of the as-synthesized composites. SQUID hysteresis loops showed a non-negligible coercive field and remanence suggesting the ferromagnetic behavior of the particles. Heating efficiency measurements showed that both samples display high heating potentials and reached magnetic hyperthermia (42 °C) in relatively short times with shorter time (~3 min) observed for γ-Fe2O3 compared to γ-Fe2O3-TiO2. The specific absorption rate (SAR) values calculated for γ-Fe2O3 (up to 90 W/g) are higher than that for γ-Fe2O3-TiO2 (~40 W/g), confirming better heating efficiency for γ-Fe2O3 NPs. The intrinsic loss power (ILP) values of 1.57 nHm2/kg and 0.64 nHm2/kg obtained for both nanocomposites are in the range reported for commercial ferrofluids (0.2–3.1 nHm2/kg). Finally, the heating mechanism responsible for NP heat dissipation is explained concluding that both Neel and Brownian relaxations are contributing to heat production. Overall, the obtained high heating efficiencies suggest that the fabricated nanocomposites hold a great potential to be utilized in a wide spectrum of applications, particularly in magnetic photothermal hyperthermia treatments.

Effects of Vibration on the Preparation of Ultrathin Sections

1973 ◽  
Vol 31 ◽  
pp. 358-359
Author(s):  
Joseph M. Blum ◽  
Edward P. Gargiulo ◽  
J. R. Sawers
Keyword(s):  
Cutting Speed ◽  
Ground Level ◽  
Environmental Vibration ◽  
Block Face ◽  
Ultrathin Sections ◽  
Embedding Medium ◽  
Thickness Variations ◽  
Building Walls ◽  
Cutting Direction ◽  
Diamond Knife

It is now well-known that chatter (Figure 1) is caused by vibration between the microtome arm and the diamond knife. It is usually observed as a cyclical variation in “optical” density of an electron micrograph due to sample thickness variations perpendicular to the cutting direction. This vibration might be induced by using too large a block face, too large a clearance angle, excessive cutting speed, non-uniform embedding medium or microtome vibration. Another prominent cause is environmental vibration caused by inadequate building construction. Microtomes should be installed on firm, solid floors. The best floors are thick, ground-level concrete pads poured over a sand bed and isolated from the building walls. Even when these precautions are followed, we recommend an additional isolation pad placed on the top of a sturdy table.

Integration of pure copper to optimize heat dissipation in injection mould inserts using laser metal deposition

2021 ◽  
Vol 33 (1) ◽  
pp. 012029
Author(s):  
Stefan Polenz ◽  
Christian Kolbe ◽  
Florian Bittner ◽  
Elena López ◽  
Frank Brückner ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Pure Copper ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Injection Mould

3-D optimal design of laminated yoke of billet heater for rolling wire rod using ON/OFF method

2012 ◽  
Vol 61 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Norio Takahashi ◽  
Shunsuke Nakazaki ◽  
Daisuke Miyagi ◽  
Naoki Uchida ◽  
Keiji Kawanaka ◽  
...  
Keyword(s):  
Optimal Design ◽  
Local Heating ◽  
Optimization Method ◽  
Optimal Topology ◽  
Field Problem ◽  
Heating Efficiency ◽  
Magnetic Devices ◽  
Wire Rod ◽  
Magnetic Recording Heads ◽  
Sensitivity Method

3-D optimal design of laminated yoke of billet heater for rolling wire rod using ON/OFF method The optimization method using the ON/OFF sensitivity analysis has an advantage that an epoch-making construction of magnetic circuit may be obtained. Therefore, it is attractive for designers of magnetic devices. We have already developed the ON/OFF method for the optimization of a static magnetic field problem, and the effectiveness is verified by applying it to the optimization of magnetic recording heads. In this paper, the ON/OFF sensitivity method is extended to the optimization of the eddy current problem using the adjoint variable. The newly developed ON/OFF method is applied to the determination of the optimal topology of the yoke of the billet heater for rolling wire rod. As a result, the optimal shape of yoke, which we could not imagine beforehand can be obtained. It is shown that the local heating of the yoke was reduced without decreasing the heating efficiency.

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