Why is countercurrent flow efficient?
Counter Flow Heat Exchanger This distributes the heat more evenly across the heat exchanger and allows for maximum efficiency. In theory, the cold fluid can exit the heat exchanger at a higher temperature than the temperature of the hot fluid outlet, although in reality this is very difficult to achieve.
What is fouling factor?
The fouling factor represents the theoretical resistance to heat flow due to a build-up of a layer of dirt or other fouling substance on the tube surfaces of the heat exchanger, but they are often overstated by the end user in an attempt to minimise the frequency of cleaning. …
Which metal has highest thermal conductivity?
Diamond is the leading thermally conductive material and has conductivity values measured 5x’s higher than copper, the most manufactured metal in the United States. Diamond atoms are composed of a simple carbon backbone that is an ideal molecular structure for effective heat transfer.
What is the difference between fin efficiency and fin effectiveness?
Therefore, the fin effectiveness can be determined easily when the fin efficiency is known, or vice versa. The thermal conductivity k of the fin material should be as high as possible. The overall effectiveness is a better measure of the performance of a finned surface than the effectiveness of the individual fins.
Can Fin effectiveness be less than 1?
The fin efficiency will always be less than one, as assuming the temperature throughout the fin is at the base temperature would increase the heat transfer rate.
What is effectiveness and efficiency in management with example?
efficient. Efficiency is when you do the same things faster or with less waste. For example, you might find a better way to run a project status meeting so it takes 30 minutes on average rather than 45 minutes. Effectiveness is finding a way to improve outcomes, perhaps by doing something very differently.
What are the advantages of a parallel flow system?
Parallel flow is similar to a electrical parallel circuit in which several parallel flow circuits of equal length connect to a supply header and a return header. A benefit of parallel is that a small diameter pipe can be used due to lower pressure drops and same money on installation.
What is counter flowing flowing?
With a counter flow arrangement, the cooling medium flows in the opposite direction to the liquid being cooled. Find out why this so much more efficient. In a shell and tube heat exchanger, coolant usually flows through the central ‘tube core’ to cool hot oil, water or air, which passes over and around the tubes.
What is the formula for efficiency?
Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula r=P/C, where P is the amount of useful output (“product”) produced per the amount C (“cost”) of resources consumed.
In which case the efficiency of fin will be maximum?
The effectiveness of a fin will be maximum in an environment with free convection. Explanation: The fin temperature is also known as the fin effectiveness. Thus it is defined as the ratio of the actual amount of the heat transfered to the to the divided base temperature in the serve.
Why is effectiveness and efficiency important?
Efficiency is important for profitability. Effectiveness is important for growth. We should be documenting our processes and systems, and then we should engage our team in brainstorming ways to do things more efficiently. By increasing efficiency we save both time and money, thus making our businesses more profitable.
What is the effect of thermal conductivity of fin effectiveness?
10a-d shows that the fin efficiency decreases monotonically (for different thermal conductivity and at a constant heat transfer coefficient) with increasing thermogeo- metric parameter. Also, it shows the variation of fin efficiency with thermogeometric in longitudinal convecting fin with insu- lated tip.
What is effectiveness example?
While efficiency refers to how well something is done, effectiveness refers to how useful something is. For example, a car is a very effective form of transportation, able to move people across long distances, to specific places, but a car may not trasport people efficiently because of how it uses fuel.
Which is more efficient parallel flow or counterflow?
Counter flow heat exchangers are inherently more efficient than parallel flow heat exchangers because they create a more uniform temperature difference between the fluids, over the entire length of the fluid path.
What is an ideal fin?
An ideal fin is the one whose temperature is equal to temperature of the surface. This is possible only if the thermal conductivity of fin material is infinitely high. The effectiveness of an actual fin material is always lower than an ideal fin.
What is critical thickness?
Critical thickness of insulation means maximum heat loss with min thermal resistance. This concept is useful in the situation when surface area of the base object increases with the insulation, i.e., cylindrical and spherical systems.
How do you calculate fin effectiveness?
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- The fin efficiency is defined as the ratio of the heat transfer to the fin to the heat transfer to an ideal fin. ηth =
- qfin. hAfin(Tb − T∞) , Tf = T∞,and Afin = 2Ac + Atip (Square and Recatngular ) 1.35.
- Atip = t × W. Fig. 2.4. Rectangular Fin. For cylindrical: Afin = πDL +
What is the most effective heat exchanger?
Plate exchanger is the most efficient due to turbulent flow on both sides. High heat-transfer coefficient and high turbulence due to even flow distribution are important. However, a plate heat exchanger regenerator is restricted to low viscosities. With high viscosities, a special tubular may be required.
What do u mean by effectiveness?
Effectiveness is the capability of producing a desired result or the ability to produce desired output. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression.
How can fin efficiency be improved?
Factors affecting fin effectiveness
- P.Kh.Ac should be greater than unity if the rate of heat transfer from the primary surface is to be improved.
- If the ratio of P and Ac is increased , the effectiveness of fin is improved.
- Use of fin will be more effective with materials of large thermal conductivities.
Which type of design of fins is more effective?
So, plate 5 will give the most effective fin type with a lower weight, surface area, size; and as a result minimum cost and maximum efficiency.
Why is countercurrent more efficient than co current?
The maximum amount of heat or mass transfer that can be obtained is higher with countercurrent than co-current (parallel) exchange because countercurrent maintains a slowly declining difference or gradient (usually temperature or concentration difference).