Free Heat Transfer In Water – Water Heat Exchanger Essay Sample

Heat transfer in water is the exchange of thermal energy between water medium depending on the temperature and pressure by dissipating heat. Basic rules determining heat transfer are that, there must be a temperature difference between the media. Also, heat will always be redeployed from a hot medium to a cold medium. Finally, the heat lost by a hot medium is equal to the amount of heat gained by the cold medium, except losses to the surrounding environment. Water heat exchange is a fluid device that efficiently transfers heat from one medium to another. It can occur directly by both media being in direct contact or indirectly by both media separated by a wall that transfers heat. Heat transfer in water – water heat exchanger is the continuous process of how heat is transferred from hot water medium to cold water medium in a system.
The process of heat transfer through movement of water or fluids is called convection. The fluid moving carries energy within it, and as fluids flow it transfers heat energy from a high-temperature location to a low temperature location. Consider heat transfer that occurs when heating water in a metal pot on a stove burner. Stove, being a source of heat, heating water in a metal pot, so as metal becomes hot, it transfers heat to the water. The water being at the base of the pan becomes hot hence decreasing density. Water density differences between the lower part of the bowl and the top of the pot lead to a gradual formation of the circulation currents. Heated water rises from the bottom to the top of the pot replacing cold water that was initially at the top. And cold water that was originally at the top moves to the bottom of the pot where there is heating and starts rising. The process is continuous until it attains the required temperature (Kreith, Manglik, & Bohn, 2010).
In addition, liquid to liquid heat exchanger uses heat-transfer fluid that circulates through the solar collector; it absorbs the heat and flow through a heat exchanger. This process transfers the heat to water in a storage tank. Heat transfer in liquids protects the solar collector from undergoing freezing in cold water. Liquid to liquid heat exchanger has either one or two barriers. The barriers are either single wall or double wall and are between the heat transfer fluid and the domestic water supply.
Single-wall heat exchanger is a pipe or sometimes tube that is surrounded by a fluid. Either the fluid passing through the tubing or the fluid that surrounds the pipe can be the fluid that undergoes heat-transfer whereas the other fluid is the potable water. The double-wall heat exchangers have two walls between the two fluids. The double-fluids are necessary for safety measures (Serth & Lestina, 2014).
Water – water duties are the largest part of production of heat exchangers, they are achieved by different methods. First is that water must undergo cooling. Water with lower temperature is for heat recovery for engine cooling, furnace cooling in the steel industry. Additionally, central cooling in power industry, process cooling in the chemical industry, cooling towers, lakes, river or sea. Secondly the water must be heated; water with higher temperature takes place in district heating, tap water heating, swimming pool heating, boilers, etc..
In conclusion, heat transfer through water medium is essential in our day to day activities. It’s applicable to a broad and various fields such as heat recovery industries, cooling towers, lakes, rivers, solar water heating systems and others.

References

Kreith, F., Manglik, R., & Bohn, M. 2010. Principles of Heat Transfer. 7th ed. Boston: Cengage Learning.
Incropera, F. P., 2011. Introduction to Heat Transfer. 6th ed. Hoboken: John Wiley & Sons.
Lienhard, J. H., 2011. A Heat Transfer Textbook. 4th ed. Cambridge: Courier Corporation.
Serth, R,W., &Lestina, T. 2014. Process Heat Transfer: Principles, Applications and Rules of Thumb. 2nd ed. Waltham: Academic Press.