#Watts to hp plus#
The total energy (internal plus mechanical) is given the symbol E. The internal energy is given the symbol U.
Often the external energy is called mechanical energy and sometimes also PV energy. The energy of an object is both internal (microscopic), like the vibrational energy of molecules or external (macroscopic) energy like kinetic or potential energy. There are many measurable properties such as like P (Pressure), V (volume) and T (temperature) which also are used for defining energy. Most objects* have a mass and energy associated with them. Energy exchanges for carrying out an objective for a process can occur by the transfer of Work, Heat or Mass, between a system and its surroundings or vice-versa. In other units we can say that on a gloabal scale, humans use about more than 500EJ's per year (1EJ = ~0.947 Quad). The estimate is that we use more than a hundred-billion Planck units of energy every year. In the Physics literature, natural units are used for energy, namely the Planck energy unit (E p) which is equal to 1.956 x 10^9 J (about 2 Billion Joules). Units: Energy is commonly measured in Joules (J). What happens to energy when it is employed for an objective? Energy degrades when energy is used for an objective. However the amount of energy is unchanges. Objective: A change in the volume (or shape), chemistry, temperature or density of an object of interest is a possible objective. The task is always to cause a change i.e. The concept of Energy (or more appropriately the concept of the exchange of Energy) is related to the latent ability to perform a task called work, transfer mass or transfer heat. Often encounter power and energy in our daily lives. (The Boiler-BHP power unit is a bit confusing becasue BHP could be confused with brake-horsepower (b hp) which is an auto-industry terminology) One BHP (Boiler Power)= 33,500 BTU/hr = 9.803 kilowatts Power rating of steam-boliers is in units of BHP (boiler -horsepower) Power-Units Conversion 1kW (KiloWatt) = 3414 BTU/hr Power is sometimes expressed in alternate units like BTU/hr or Horsepower (hp)
the energy used (or supplied) per unit time. Energy units employed by electric companies are the kWhr (Kilo-Watt-Hour for electric) or Therm (for gas).ġ000J = 1kJ (KiloJoule) = 0.9485 BTU=0.0002778 kWhrġPJ (PetaJoule)= 1,000,000,000,000,000 i.e. The JOULE (J) is a commonly used unit of energy. MHI 101: Energy, Power and Thermodynamics Tutorial Next divide each side by 5252 and you end up with this equation:īecause of this math, lb-ft of torque and horsepower will always be the same at 5,252 RPM. x 2π x revolutions/minĭivide each side by 2π (6.28315) and you get 5,252 lb-ft / min = lb-ft. We would like to get rid of the 2π and we need to consider that 1 H.P. Power = Torque x 2π x Revolutions / Minute The formula for power now looks like this. Just like a revolution, radians have no unit of measure, which works out well because torque already has the displacement unit (feet) in it. Hence, there are 2π radians in every revolution. It is the same no matter the size of the circle. A radian is an angle where the radius is the same length as the length of the arc created by that angle. Since we are dealing with rotary motion it is called Angular Speed and it is expressed in Radians/sec or Revolutions/Minute. We know that Work is achieved when there is Force and Displacement. Notice that although physically torque is a force, mathematically it already has the same units as work. We will use a brake and a torque arm when measuring the torque of an engine. radius we are applying 30 lb-ft of torque. Torque is the force applied through or derived through a lever or torque arm that will rotate about a fulcrum or pivot. We are dealing with engines where the force and power are delivered in rotary motion.
0 kommentar(er)
