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  2. Heat transfer coefficient - Wikipedia

    en.wikipedia.org/wiki/Heat_transfer_coefficient

    Various authors have correlated charts and graphs for different geometries and flow conditions. For flow parallel to a plane surface, where x {\displaystyle x} is the distance from the edge and L {\displaystyle L} is the height of the boundary layer, a mean Nusselt number can be calculated using the Colburn analogy .

  3. Rate of heat flow - Wikipedia

    en.wikipedia.org/wiki/Rate_of_heat_flow

    The rate of heat flow is the amount of heat that is transferred per unit of time in some material, usually measured in watts (joules per second). Heat is the flow of thermal energy driven by thermal non-equilibrium, so the term 'heat flow' is a redundancy (i.e. a pleonasm). Heat must not be confused with stored thermal energy, and moving a hot ...

  4. Newton's law of cooling - Wikipedia

    en.wikipedia.org/wiki/Newton's_law_of_cooling

    When stated in terms of temperature differences, Newton's law (with several further simplifying assumptions, such as a low Biot number and a temperature-independent heat capacity) results in a simple differential equation expressing temperature-difference as a function of time. The solution to that equation describes an exponential decrease of ...

  5. Pinch analysis - Wikipedia

    en.wikipedia.org/wiki/Pinch_analysis

    Pinch analysis is a methodology for minimising energy consumption of chemical processes by calculating thermodynamically feasible energy targets (or minimum energy consumption) and achieving them by optimising heat recovery systems, energy supply methods and process operating conditions.

  6. Thermal efficiency - Wikipedia

    en.wikipedia.org/wiki/Thermal_efficiency

    So, for a boiler that produces 210 kW (or 700,000 BTU/h) output for each 300 kW (or 1,000,000 BTU/h) heat-equivalent input, its thermal efficiency is 210/300 = 0.70, or 70%. This means that 30% of the energy is lost to the environment. An electric resistance heater has a thermal efficiency close to 100%. [8]

  7. Coefficient of performance - Wikipedia

    en.wikipedia.org/wiki/Coefficient_of_performance

    The COP of absorption chillers can be improved by adding a second or third stage. Double and triple effect chillers are significantly more efficient than single effect chillers, and can surpass a COP of 1. They require higher pressure and higher temperature steam, but this is still a relatively small 10 pounds of steam per hour per ton of cooling.

  8. Temperature–entropy diagram - Wikipedia

    en.wikipedia.org/wiki/Temperature–entropy_diagram

    In thermodynamics, a temperature–entropy (T–s) diagram is a thermodynamic diagram used to visualize changes to temperature (T ) and specific entropy (s) during a thermodynamic process or cycle as the graph of a curve. It is a useful and common tool, particularly because it helps to visualize the heat transfer during a process.

  9. Joule–Thomson effect - Wikipedia

    en.wikipedia.org/wiki/Joule–Thomson_effect

    In thermodynamics, the Joule–Thomson effect (also known as the Joule–Kelvin effect or Kelvin–Joule effect) describes the temperature change of a real gas or liquid (as differentiated from an ideal gas) when it is expanding; typically caused by the pressure loss from flow through a valve or porous plug while keeping it insulated so that no heat is exchanged with the environment.