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Environmental and Social Impact
Published in Ajai, Rimjhim Bhatnagar, Desertification and Land Degradation, 2022
DTR is basically related to the thermal inertia of the land as well as the surface energy balance. There exists an inverse relation between thermal inertia and DTR, the higher the thermal inertia lower is the DTR. Thermal inertia is a bulk property and is a measure of the resistance of a material to change in temperature. It can also be defined as ‘property of a material that expresses the degree of slowness with which its temperature reaches that of its surrounding'. A body or material having high thermal inertia will warm up or cool down slowly as compared to the one having low thermal inertia values. It is defined by Equation 5.1: P=ρ⋅K⋅C
Failure 3: effects of fire on building materials
Published in Ash Ahmed, John Sturges, Materials Science in Construction: An Introduction, 2014
Thermal inertia is the property that determines how quickly a material surface heats up when impacted by radiant or convected heat. It is a very important material property when good passive design is being considered. As with diffusivity, it depends on the same three properties of thermal conductivity (k), density (t) and specific heat capacity (Cp). Thermal inertia is calculated thus: Thermal Inertia = k × t × Cp
Urban Heat Implications from Parking, Roads, and Cars: a Case Study of Metro Phoenix
Published in Sustainable and Resilient Infrastructure, 2022
Christopher G. Hoehne, Mikhail V. Chester, David J. Sailor, David A. King
In addition to albedo and emissivity, altering a pavement’s thermal inertia properties has noticeable impacts on the diurnal sensible heat flux magnitudes. Thermal inertia describes the slowness of material to approach thermal equilibrium (e.g., high thermal inertia materials are slower to reach thermal equilibrium) and is equivalent to the square-root of the product of the thermal conductivity (), density (), and specific heat capacity () with SI units of J m−2 K−1 s−1/2. An increase in a pavement surface layer thermal inertia by 100 J m−2 K−1 s−1/2 resulted in a decrease of maximum afternoon outgoingsensible heat fluxes 8.6 W m–2 (95% confidence interval: 1.1 to 16 W m–2; R2 = 0.57; p = 0.031) and an increase in minimum nighttime outgoing sensible heat fluxes by 1.7 W m–2 (95% confidence interval: 1.1 to 2.3 W m–2; R2 = 0.88; p < 0.001). Thermal conductivity was the most influential thermal inertia factor influencing minimum and maximum sensible heat fluxes, while specific heat capacity was the least impactful. With the exception of subsurface thermal conductivity, subsurface layer thermal inertia properties were insignificant in influencing the diurnal outgoing sensible heat fluxes at the surface.
Collaborative scheduling of source-network-load-storage considering thermal inertia of the integrated electricity and district heating systems
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Wanying Xie, Qifen Li, Yongwen Yang, Qiaoni Wei
Electricity responds instantaneously, has no time lag or loss, and has small inertia. While the heat transmission speed in the heating system is slow with a certain delay and heat loss. Thermal inertia is defined as the characteristic affected by the specific heat capacity of its medium, which is mainly reflected in the DHN and heating buildings (Gu et al. 2017). DHN can be regarded as a huge virtual heat storage system, due to the thermal inertia of the heat medium in the pipeline (Wu et al. 2018). Notably, this characteristic is associated with the temperature of the heating medium in DHN. For end-users with high heating temperature or flow demand (such as industrial end-users), the heat load may be covered by higher pressure and increased flow in DHN. To emphasize the contribution of thermal inertia, only the space heating is considered as thermal loads of IEDHS in this paper. The heating variations in a short time (minutes or even hours) have a slow or even subtle effect on the indoor heating quality owing to the heat storage capacity of the building envelope and indoor air (Guarino et al. 2015). In addition, the end-users have lagging feedback on heat supply variations, and the essence of their potential energy consumption is to allow space temperature to fluctuate within a certain range. This thermal load elasticity is another flexible opportunity for the power dispatch of IEDHS (Cheung et al. 2019).
From Cells to Residues: Flame-Retarded Rigid Polyurethane Foams
Published in Combustion Science and Technology, 2020
M. Günther, A. Lorenzetti, B. Schartel
The application areas of rigid polyurethane foams (RPUF) as an insulation material include not only the construction industry and refrigeration, but also the pipe and tubing industry. Offering excellent insulating properties, RPUFs outperform any other commercially available insulating material due to their extremely low thermal conductivity. (Engels et al. 2013; Szycher 2012) These unique characteristics are based on the cellular structure of RPUFs, which, unfortunately, also is responsible for their poor fire behavior. For thermally thick combustible materials, the time to ignition is proportional to their thermal inertia, which is defined as the product of thermal conductivity (), density () and heat capacity (). (Lyon 2003; Madrzykowski and Stroup 2008) and are typically very low for foams, causing their low thermal inertia. Keeping the intensity of a given heat flux constant, the surface temperature of an exposed cellular polymer rises more rapidly than that of a solid polymer with a high value. (Cleary and Quintiere 1991) The low thermal inertia benefits not only ignitability but also flame spread, which is why RPUFs are considered to be hazardous materials. (Hilado 1967; Hirschler and Shakir 1991; Levchik 2006)