What is the heat removal factor?
What is the heat removal factor?
The heat removal factor (FR) is the ratio of the actual heat transfer to the maximum possible heat transfer through the collector plate. A special case showing the effect of phase change material (PCM) on FR in the case of serpentine is discussed.
What is hottel Whillier Bliss equation?
Hottel-Whillier-Bliss (HWB) equation is a reduced form of an instantaneous thermal efficiency of conventional flat plate collector in the term of design parameters such as the heat removal factor (FR), the effective transmittance-absorptance product (( α τ )eff) and the overall heat loss coefficient (UL) (Smith and …
How do you calculate flat plate collector efficiency?
= Ti+Qufl ( rhCp ). The mean plate temperature will always be greater than the mean fluid temperature due to heat- transfer resistance between the absorbing surface and fluid. The mean plate temperature may be used to calculate the collector efficiency, i.e.
How do you calculate heat removal?
Heat is an important component of phase changes related to work and energy. Heat transfer can be defined as the process of transfer of heat from an object at a higher temperature to another object at a lower temperature….Q=m \times c \times \Delta T.
| Q | Heat transferred |
|---|---|
| \Delta T | Difference in temperature |
How much power from the sun intercepted by the Earth is approximately?
approximately 1.8 ´ 1011 MW
The power from the sun intercepted by the earth is approximately 1.8 ´ 1011 MW, which is many thousands of times larger then the present consumption rate on earth of all commercial energy sources. Thus in principle, solar energy could supply all the present and future energy needs of the world on a continuing basis.
Which parameters can affect on performance of flat plate collector?
Water is considered in the present study as the working fluid. Other factors affect the efficiency of the collector as the water rate of flow, selective coatings of the front surface of the absorber, heat losses by convection and radiation, the surface absorptivity of the surface.
Which collector has maximum efficiency?
In tests, Absolicon solar collector has shown to have an efficiency of 76.6%. This is the highest number ever achieved for a small parabolic trough.
What is the correct formula for the rate of heat transfer?
q = k A l ΔT.
How much of the earth is in light at any one time?
Only half the Earth is ever lit by the Sun at one time, which halves the total solar irradiance. Energy from sunlight is not spread evenly over Earth.
Which is correct for the heat removal factor Fr?
Multiplying both the transmission absorptance product and the proportionate heat loss by the heat removal factor FR, we have Eqn (4.7). η = collector efficiency, FR = heat removal factor, ¯ τα = effective transmissivity–absorptivity product,
What is the heat removal factor of a solar collector?
It is convenient to define a quantity that relates the actual useful energy gain of a collector to the useful gain if the whole collector surface were at the fluid in let temperature. This quantity is known as “the collector heat removal factor (F R
What is the heat removal factor of unity?
It is the fraction utilized by a collector having no optical losses and a heat removal factor of unity i.e., FR (τα) = 1, operating at a fixed inlet to ambient temperature difference. It should be noted that the utilizability of this collector is always less than 1, since thermal losses exist in the collector.
How to calculate a ton of refrigeration heat?
HVAC FORMULAS TON OF REFRIGERATION – The amount of heat required to melt a ton (2000 lbs.) of ice at 32°F 288,000 BTU/24 hr. 12,000 BTU/hr. APPROXIMATELY 2 inches in Hg. (mercury) = 1 psi WORK = Force (energy exerted) X Distance Example: A 150 lb. man climbs a flight of stairs 100 ft. high Work = 150 lb. X 100 ft. Work = 15,000 ft.-lb.
