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energy/volume of the fuel; There are two kinds of enthalpy of combustion, called high(er) and low(er) heat(ing) value, depending on how much the products are allowed to cool and whether compounds like H 2 O are allowed to condense. The high heat values are conventionally measured with a bomb calorimeter. Low heat values are calculated from high ...
The convective heat transfer between a uniformly heated wall and the working fluid is described by Newton's law of cooling: = where represents the heat flux, represents the proportionally constant called the heat transfer coefficient, represents the wall temperature and represents the fluid temperature.
The role of a heat exchanger is to transfer heat between two mediums, so the performance of the heat exchanger is closely related to energy or thermal efficiency. [11] A counter flow heat exchanger is the most efficient type of heat exchanger in transferring heat energy from one circuit to the other [citation needed].
It is used in calculating the heat transfer, typically by convection or phase transition between a fluid and a solid. The heat transfer coefficient has SI units in watts per square meter per kelvin (W/(m 2 K)). The overall heat transfer rate for combined modes is usually expressed in terms of an overall conductance or heat transfer coefficient ...
The heat capacity is a function of the amount of heat added to a system. In the case of a constant-volume process, all the heat affects the internal energy of the system (i.e., there is no pV-work, and all the heat affects the temperature).
V = volume n = number of moles R = universal gas constant T = temperature. The ideal gas equation of state can be arranged to give: = / or = / The following partial derivatives are obtained from the above equation of state:
Since heat density is proportional to temperature in a homogeneous medium, the heat equation is still obeyed in the new units. Suppose that a body obeys the heat equation and, in addition, generates its own heat per unit volume (e.g., in watts/litre - W/L) at a rate given by a known function q varying in space and time. [5]
In monatomic gases (like argon) at room temperature and constant volume, volumetric heat capacities are all very close to 0.5 kJ⋅K −1 ⋅m −3, which is the same as the theoretical value of 3 / 2 RT per kelvin per mole of gas molecules (where R is the gas constant and T is temperature). As noted, the much lower values for gas heat ...