Effects of body positions and garment design on the performance of a personal air cooling/heating system

Indoor Air ◽  
2021 ◽  
Author(s):  
Lun Lou ◽  
Yuen Shing Wu ◽  
Yiying Zhou ◽  
Jintu Fan
Keyword(s):  
Heating System ◽  
Air Cooling ◽  
Garment Design

A full air cooling and heating system based on mine water source

2018 ◽  
Vol 145 ◽  
pp. 610-617 ◽  
Author(s):  
Xiao-Ping Feng ◽  
Zhemin Jia ◽  
Hao Liang ◽  
Zhenping Wang ◽  
Baoqi Wang ◽  
...  
Keyword(s):  
Mine Water ◽  
Water Source ◽  
Heating System ◽  
Air Cooling

Research on one-step quenching and partitioning treatment and its application in hot stamping process

2015 ◽  
Vol 231 (11) ◽  
pp. 1972-1982 ◽  
Author(s):  
Xianhong Han ◽  
Yaoyao Zhong ◽  
Pensen Xin ◽  
Zhenshan Cui ◽  
Jun Chen
Keyword(s):  
Hot Stamping ◽  
Heating System ◽  
Active Role ◽  
Mechanical Tests ◽  
Crash Test ◽  
Boron Steel ◽  
Air Cooling ◽  
Element Analysis ◽  
Quenching And Partitioning ◽  
Stamping Process

Hot stamping process has been regarded as one of the most attractive processes to produce high-strength parts with merits of low-forming load and small springback. However, the elongation of the hot-stamped parts is small, so the ability of crash resistance is limited. Recently, a novel hot stamping process integrated with quenching and partitioning treatment has been presented to improve the elongation of the final parts. In this article, the quenching and partitioning hot stamping process is further studied using the boron steel B1500HS, and the feasibility is verified by a series of quenching and partitioning tests followed by mechanical tests and microstructure observations. Moreover, an experimental tool for quenching and partitioning hot stamping process is first proposed in this article, where both air cooling device and heating system are designed, and a U-channel part is produced. Finally, in order to illustrate the active role of high elongation that the quenching and partitioning hot stamping process archived, numerical simulation of crash test for a B-pillar sample is conducted using finite element analysis software LS-DYNA.

scholarly journals USE OF THERMAL PROCESSES TO OBTAIN ELECTRICITY

2021 ◽  
Vol 24 (1) ◽  
pp. 59-63
Author(s):  
LYUBIMENKO E.N. ◽  
◽  
SHTEPA A.A. ◽  
SIKIRIN D.R. ◽  
◽  
...  
Keyword(s):  
Temperature Difference ◽  
Negative Impact ◽  
Heating System ◽  
Practical Significance ◽  
Air Cooling ◽  
Peltier Element ◽  
Active Cooling ◽  
Cooling Fan ◽  
Living Space ◽  
Increasing Temperature

As a result of the analysis of the research results, it is easy to see that the voltage at the output of our electrothermal generator increases with increasing temperature difference between the surface of the heating system pipe and the aluminum air cooling radiator, between which are Peltier elements. However, the efficiency of such a generation is much lower than the efficiency indicated in the development guides of the corresponding model of the Peltier element (Appendix B). The reason for this is, obviously, the negative impact of the applied structural elements of the created model, which reduce the efficiency of heat transfer between the source of the temperature difference and the Peltier element. The step-up voltage converter used in the created model allows to receive necessary for power supply of useful devices of 5 V of a voltage on an output of the generator, but according to the parameters, this device needs a certain (though rather small) voltage on the input. In the study without load, we were able to obtain at the output of the converter 5 V standard voltage at a temperature difference ΔT = 16.1 ° C. Instead, in the second study, when the output of the converter was used as a source for the cooling fan, the required 5 V was achieved only at ΔТ = 23.2 ° С. This temperature difference is easily achieved by the surface of the heating radiator and the air of the living space during the heating season. That is, a generator based on four Peltier elements TPP 1 - 12706 will really be able to produce the required amount of electricity to power useful devices and charge mobile devices. Of particular interest is the result of a study of the efficiency of active air cooling, powered by the output of our generator. As we can see, the voltage at the Peltier elements under the conditions of the current at the generator output (Fig. 4, dependence 4) is noticeably lower than that in the case of the no-load experiment (Fig. 4, dependence 1). But only until the step-up converter can provide a voltage of 5 V (Fig. 4, dependence 3 has a jump near ΔT = 23.2 ° C) to power the fan active cooling radiator! After that, the active cooling fan is switched on and the generation efficiency becomes higher than that during the idling study. This means that the use of active cooling of the radiator makes sense in such devices. The scientific novelty of the work is to confirm the possibility of creating a heat generator using as a source of energy available in everyday life temperature difference, in particular, obtained the characteristics of the modern Peltier element. The practical significance of the work lies in the possibility of using the device at home when using a heated battery to obtain electricity that can be used to connect a flashlight, humidifier, charge the fitness bracelet.

Numerical Simulation on Indoor Thermal Environment of Radiant Flooring Cooling System with Displacement Ventilation

2013 ◽  
Vol 743 ◽  
pp. 90-93
Author(s):  
Wei Cai ◽  
Wen Lv ◽  
Le Xian Zhu ◽  
Peng Feng Yang
Keyword(s):  
Thermal Environment ◽  
Cooling System ◽  
Heating System ◽  
Human Model ◽  
Air Cooling ◽  
Displacement Ventilation ◽  
Air Cooling System ◽  
Radiant Floor Cooling System ◽  
Radiant Floor Heating System ◽  
Cfd Method

The purpose of this study is to investigate the thermal environment of a radiant floor cooling system using the existing radiant floor heating system. The thermal environment of the model office space was analyzed using Computational Fluid Dynamics (CFD) method. Two typical air distributions (hybrid air cooling system composed of radiant floor cooling and displacement ventilation and all-air system) were simulated. Installing two human models in the office, the characteristics of heat transportation from the human model were also analyzed. The results show that two air distribution forms can meet the demand of thermal comfort. The operative temperature in the radiant floor cooling system was lower than in the all-air cooling system when each of the sensible cooling loads of the two types of HVAC system was the same.

scholarly journals The Effect of Icing on the Output Parameters of the Airflow-Angle Sensor in Case of Failure of the Electric Heating System

2021 ◽  
Vol 19 (4) ◽  
pp. 69-75
Author(s):  
A. A. Zadorozhniy ◽  
N. D. Aleksanin
Keyword(s):  
Control Method ◽  
Electric Heating ◽  
Heating System ◽  
Research Problem ◽  
Full Scale ◽  
Air Cooling ◽  
Angle Sensor ◽  
Full Scale Experiment ◽  
Cooling Tube ◽  
Scale Experiment

At present, with the intensive operation of aircrafts in extremely harsh air conditions, their all-weather use, the work related to improving the flight safety is especially relevant. One of the directions of work in this topic is the study of the types of parametric failures of onboard equipment associated with the influence of the external environment in order to assess their impact on interacting systems and develop recommendations for identifying and countering detected failures. The presented paper considers the results of a full-scale experiment to determine the possibility of operation of the aerodynamic angle sensor in artificially formed icing conditions in case of failure of its electric heating system, as well as a description and results of subsequent modeling of the sensor icing process, and an assessment of its effect on the accuracy characteristics of the sensor output signal. The statement of the research problem is formulated as follows: it is necessary to ensure the testing of the sensor and the subsequent processing of the results obtained in order to form a generalized mathematical model of the sensor icing process, as well as to solve the problem of introducing additional errors into the sensor signals, which makes it possible to study the behavior of air signal systems using vane sensors of aerodynamic angles with artificially introduced failures. A full-scale experiment was carried out in an air-cooling tube on the basis of the enterprise JSC "UKBP". Numerical modeling and determination of correction factors were carried out in the software packages Ansys FENSAP ICE and MathCAD. Analysis of the results achieved in the course of modeling confirmed the convergence of the model obtained with the data of real experiments in an air-cooling tube. The data obtained made it possible to confirm the possibility of detecting distorted values for the angle of attack by the parametric quorum control method.

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

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