المبادلات الحرارية

[left]Heat Exchanger:
A heat exchanger is a device which can be used to transfer heat energy from one source to a conveying medium. This usually means from a fluid to another fluid. This includes both liquids and gases. The heat source and the conveying medium are separate and the heat exchanger conveys the heat between the two. Heat exchangers are common in our homes. For example, the coils on the back of our refrigerators are heat exchangers. Domestic boilers also commonly used heat exchangers. These type of boilers are known as condensing boilers because the heat in the flue is reduced in comparison with a conventional boiler. This create condensation in the flue and this means that these boilers must be connected to a drain to collect water which will trickle out. The boilers are also known for “pluming”. This is the ejection of steamy clouds from the external vent which is most obvious on cold and damp days.
The plate and frame heat exchanger is the compact heat exchanger, much smaller than an equivalent double pipe exchanger. The function of a heat exchanger is to exchange heat between a hot fluid and a cold fluid. The plate provides a large surface for heat transfer. The plates are arranged like slices of bread with gaskets between the slices and hung on a frame which allows the stack to be compressed sealing the gaskets. The hot and cold fluids alternate down the stack, the hot fluids transfer heat to the cold fluids. In the auto radiator example, the cooled oil could be returned to the engine and the heated antifreeze could be sent to the radiator.
Heat pump:
The demand for factors which can utilize heat and energy in a more efficient way is rising day by day. To supply heat energy throughout the year, heat pumps are a viable option. The heat pump industry uses advanced technology to provide heat energy throughout the year to places for various purposes. The concept is carried by providing heat; where air is exchanged with heated air.
Heat pumps are also called heaters in some places. The main function of heaters or heat pumps is exactly reverse as that of air conditioners. As Air Conditioners turns hot air into cool air, heat pumps exchange cool air with hot air. Heat pumps have a feature that helps the user to set the temperature according to his/her preferences. There are heat pumps introduced in the market which performs both the function of exchanging cool air with hot air and vice versa. Heat pumps are an efficient and economical method to manage temperature.
Heat balance:
Heat balance is a common term which is used for various subjects. Heat balance in general terms means that the input heat and output heat should be equal. The term is used for diverse subjects as much as from space craft, earth on the whole, human body and of course in Steam boilers.
In terms of statistics the sum of both the heats should be equal to 0. The term heat balance is also used in steam boilers. To be able to calculate heat balance of steam boilers, we need to consider all the values of heat. We need the balance of heat for the whole system rather than a particular part of the steam boilers.
The heats that need to be considered with respect to Boilers is the heat that goes in to it from burning fuels, the burner exhaust that is emitting heat out, the loses from the piping which is called thermal loss, apart from all the losses include loss from external surface that are caused by when local atmosphere is heated, the heat loss from the outflow of steam from the boiler.
All in all, the heat balance conforms with the theories that have been developed from a long time and is a very important in designing a stream boiler in order have an efficient boiler