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Introduction to Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
Specific heat capacity of a substance is the amount of heat required to raise the temperature of the unit mass of the substance by 1°C. Latent heat is the quantity of heat evolved or absorbed to change the state of a unit mass of a substance without any change in its temperature.
Thermodynamic Basics
Published in Keith L. Richards, Design Engineer's Sourcebook, 2017
The specific heat capacity of any substance is defined as the amount of energy required to raise a unit mass through one degree temperature rise. In thermodynamics, there are two specified conditions used:Constant volume (Cv)Constant pressure (Cp)
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Published in Pablo La Roche, Carbon-Neutral Architectural Design, 2017
The heat capacity of a system is the amount of heat required to change the temperature of a whole system by 1°C. Specific heat capacity is defined as the amount of heat required to raise the temperature of a unit volume or unit mass of a material by one unit of temperature. In the SI units, heat capacity is expressed in units of joule(s) (J) per kelvin (K) per unit mass (kJ/kg K). It is also expressed in kJ/kg °C or Btu/lb °F (Table 8.4). It is roughly proportional to the density of the material, with denser materials typically having a higher specific heat capacity than materials with lower density. An important exception is water, which stores much more heat per unit weight than concrete, which is denser. Buildings with massive structures and high heat capacities will act as heat sinks, absorbing and storing heat from the interior of the space (Figure 8.15).
2-D FEM thermomechanical coupling in the analysis of a flexible eRoad subjected to thermal and traffic loading
Published in Road Materials and Pavement Design, 2023
Talita De Freitas Alves, Thomas Gabet, Rosângela Motta
Assuming that there is no heat sources and sinks, the net heat fluxes must be equal to the storage rate of thermal energy: Where is the density of the material, in kg/m3; is the specific heat capacity, in J/(kg⋅°C); and is the partial derivative of the temperature with respect to time. The specific heat capacity is defined by the amount of heat required to cause a change in temperature by 1°C of a unit of mass of the material. Finally, the Fourier's partial differential equation is the simple balance of and , that must be satisfied in every point x for every moment :
Optimizing submersible pump regulation of a clogging prone groundwater heat pump system in Melhus, Norway
Published in Science and Technology for the Built Environment, 2023
Lars A. Stenvik, Randi K. Ramstad, Bjørn S. Frengstad
where is the specific heat capacity of water (= 4182 J/kg/°C). In heating mode, a too low Q may reduce the groundwater temperature below water’s freezing point, which would be detrimental to the GWHP system. Conversely, a higher pumping rate Q will lower ΔTgw, and increase the evaporation temperature of the heat pump. This means the required compressor power consumption (), which is needed to lift the temperature of the heat pump’s working fluid to the level required by the heat distribution system, will be reduced. will be converted to heat (PHP) which can be utilized by the heat distribution system (Stene 2001). The groundwater pumping rate Q is therefore a fit parameter to maximize the seasonal performance factor SPF. SPF is the time integrated GWHP coefficient of performance (COPGWHP) over a period Δt = t2 – t1 (modified from equation as quoted in Banks 2012):
The Effects of Thermal-mechanical Coupling on the Thermal Stability of Coal
Published in Combustion Science and Technology, 2022
Jiangkun Chao, Rongkun Pan, Xuefeng Han, Hongyan Ma, Tian Qiu, Daimin Hu
It can be seen from Figure 5 and Table 3 that in the initial endothermic stage, with the increase of temperature, the heat flow curve first decreases and then increases, forming a smaller absorption peak. The heat flow curves basically coincided as the initial temperature increased. After the endothermic stage was reached, the maximum endothermic temperature Tmax exhibited hysteresis as the initial temperature increased. The endothermic heat flow peak value and heat absorption decreased as the initial temperature because the chemical activity of the coal was enhanced after the heat pretreatment. Temperature is an important factor that affects the specific heat capacity. The specific heat capacity and the temperature were linearly related below 500°C. It can be seen from the experimental results that the specific heat capacity of the coal samples gradually decreased as the initial temperature increased. At the same time, it can be seen from the comparison of (a), (b), (c), (d) and (e) in Figure 5 that when the initial stress is 20 MPa, the temperature has a greater effect on the heat flow value of the coal sample.The peak value of endothermic heat flow increases with the increase of initial temperature, and the amount of heat absorption decreases with the increase of initial temperature.