Search results
Results From The WOW.Com Content Network
In counter-flow heat exchangers the fluids enter the exchanger from opposite ends. The counter current design is the most efficient, in that it can transfer the most heat from the heat (transfer) medium per unit mass due to the fact that the average temperature difference along any unit length is higher. See countercurrent exchange.
In boilers, economizers are heat exchange devices that heat fluids, usually water, up to but not normally beyond the boiling point of that fluid. Economizers are so named because they can make use of the enthalpy in fluid streams that are hot, but not hot enough to be used in a boiler, thereby recovering more useful enthalpy and improving the boiler's efficiency.
A hot water reset control loop measures the outside air temperature; this information is used to estimate demand or heating load as the outdoor temperature varies. The supply hot water temperature is modulated up and down range in an inverse linear ratio to outside air temperature. The typical range for conventional boilers is to vary the ...
A condenser is designed to transfer heat from a working fluid (e.g. water in a steam power plant) to a secondary fluid or the surrounding air. The condenser relies on the efficient heat transfer that occurs during phase changes, in this case during the condensation of a vapor into a liquid. The vapor typically enters the condenser at a ...
a boiler whose primary heating surface is composed of many small tubes, filled with water. Tubes of 3 inch diameter and above are termed "large-tube" boilers. Later water-tube designs used smaller "small-tubes" of 2 inches or less. Wet bottom furnace.
Radiator (heating) Heat exchange by built-in bathroom radiator uses hot water flow through the stainless steel pipes seen here to raise the temperature of the ambient air. The radiator depicted here also serves as a towel rack and warmer. Radiators and convectors are heat exchangers designed to transfer thermal energy from one medium to another ...
A thermostatic radiator valve on position 2 (15–17 °C) Installed thermostatic radiator valve with the adjustment wheel removed. A thermostatic radiator valve ( TRV) is a self-regulating valve fitted to hot water heating system radiator, to control the temperature of a room by changing the flow of hot water to the radiator.
Temperature control valves are used to blend hot supply water into the return to avoid thermal shock or condensation inside of the boiler. The lower the return temperature to the boiler the more likely it will be in condensing mode. If the return temperature is kept below approximately 55 °C (131 °F), the boiler should still be in condensing ...