What is Heat exchanger: Definition and 168 Discussions
A heat exchanger is a system used to transfer heat between two or more fluids. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact. They are widely used in space heating, refrigeration, air conditioning, power stations, chemical plants, petrochemical plants, petroleum refineries, natural-gas processing, and sewage treatment. The classic example of a heat exchanger is found in an internal combustion engine in which a circulating fluid known as engine coolant flows through radiator coils and air flows past the coils, which cools the coolant and heats the incoming air. Another example is the heat sink, which is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant.
Okay, I'm having trouble with a heat transfer HW problem. We are designing a tube-in-shell steam condenser.
We are given:
\dot{m}steam = 4.38kg/s
Tsteam = 378K
the steam is saturated 90%
Tc of cooling water = 293.15K
Th of cooling water = 296.5K
For the tubes in the bundle:
Inner...
I am designing a heat exchanger to be used in a house to circulate air from the outside. I have very basic knowledge on the subject and would appreciate any input. I have looked up various topics on the subject and am using "introduction to thermal and fluid engineering" by Kaminski. However...
I'm not usually into the "green" thing, but an unrelated interest brought me to the topic of spiral heat exchangers and I also received some encouragement.
The idea is a small, low cost spiral heat exchanger for use in village sized water treatment, desalination, and for making showers...
Homework Statement
Refrigerant 134a enters a heat exchanger operating at steady state as a superheated vapor at 10 bars, 60C, where it is cooled and condensed to saturated liquid at 10 bars. The mass flow rate of the refrigerant is 10 kg/min. A separate stream of air enters the heat exchanger...
First off, I can't believe I never decided to search for a forum like this, I love smart people! lol.
Anyways I am working on a Liquid cooling project for a highly overclocked computer system. Originally I wasn't going to use a heat exchanger(Matter of fact, until I stumbled across one on a...
Heya, id like a little help calculating the efficiency of some steam heat exchangers. They are used in industrial dryers, steam goes through the radiator and then air is blowed to it in order to heat the fabric.
Currently my radiators are made from carbon steel tubes and fins, it has 78 flat...
Our tin plating line has several of these. Original design was superheated steam to 300 degrees Celcius, but the plant reduced steam pressure and now our steam inlet temperature is much lower (less than 150 degrees Celcius). Inlet air is what we want to heat up for the drying. It comes in...
I need to do an energy balance on a heat exchanger where an aziotropic mixture of 90% methanol and 10% water at 21°C is being heated to 261°C. The heat source is high pressure saturated steam at 31 bar and it is assumed that the steam leaves as condensate at the same pressure (31bar)...
Hello, my first post. I hope this is the right forum...
I'm considering a heat exchanger to solve a problem.
I've purchased a tankless water heater for home usage - look at it as a black box, cold water flows in, hot water flows out.
Output temperature is quite constant due to a digital...
Hi, i do a motorsport where a normal cooling system for the engine cannot be used as it gets damage so we use solid water tanks along the bulkhead of the car, these arent the greatest as they tend to get hot as they're not really a cooling system at all. My idea would be to make a water tank...
Hello everybody
The problem is about a very simple heat exchanger.
One pipe with cold water at the inlet and at some points heat is applied uniformly. Assumed no buoyancy. Wall is smooth and with no slip.
I simulate different a matrix of volume flow rates and inlet water temps. For 5...
Good Evening,
I am currently desiging a heat exchanger to heat Air from 10 oC to 110oC and cool flue gas from 1259.4 oC to 725 oC.
As both fluids are gases, i would like to know if it is advicable to use a shell and tube heat exchanger?
Could you suggest a heat exchanger type please ...
Homework Statement
see attachment
Homework Equations
C for cold side = mass flow rate of cold*Cp
Cp is specific heat
1.) NTU=UA/Cmin
2.) ε=q/qmax
3.) qmax=Cmin*(T hot,in - T cold,in)
4.) NTU=(1/(Cr-1))*ln((ε-1)/(ε*Cr-1)) (Cr<1)
5.) Cr= Cmin/Cmax
for the two small...
For a double-pipe heat exchanger operating with countercurrent flow, the operating equation is:
S = (1 - exp X)/ (R - exp X) X = ((U*A)/(Ma*Ca)) (1-R)
where R and S are defined by:
R = (Ma*Ca)/( Mb*Cb) = (Tb2 - Tb1)/(Ta1 - Ta2)
S = (Ta1 - Ta2)/(Ta1- Tb1)
(i) Show how...
Homework Statement
In this flat plate heat exchanger, rippled plates (0.3 m thick each) create channels that allow heat transfer between a hot and a cold fluid. Conduction occurs then from the heat temperature difference between the two fluids while convection occurs as the fluids move...
We have 3 interstage coolers for a Synthesis gas compressor.Synthesis gas is mostly H2 & N2 with small Ar & CH4.Tube side fluid is water & shell side fluid is Syn.gas.The heat exchangers are made of carbon steel.Now due to corrosion in tube to tubesheet joint we like to use SS for tubes.But our...
HHi all,
I'm working on spiral/plate heat exchanger design and the temperature difference is to be 400c.
I need some one to guide me through it.
Thanks
Hi all,
Im new to this forum and would greatly appreciate any help i can get.
I work for a solar hot water company and we have taken on an unhappy client who has been sold a custom thermal storage tank (by another firm), with a corrugated stainless steel tube immersion heater. The hot...
Hi, I am trying to show the heat transfer from a hot stream to a cold stream in ansys. I can do everything but not to define the wall's heat capacity which separates the two streams. Where and how would I do this? Thanks
So this concept is confusing me.
You have a 20GPM, 150Degree F, 40PSIG water coming into a heat exchanger through a 1" diameter pipe.
Chilled water is available for cooling from a 6" diameter line at 40 Degrees F, With a pressure of 110PSIG and a flow of 270GPM.
The original...
Heat Exchanger!
I have steam flowing past two pipes which have cold water flowing in them. I want to find out how much heat is lost from the cold water and thus the final temperature of the cold water when it leaves the pipe.
I am doing this as an experiment and before I start I want to know...
Homework Statement
I'm trying to derive the \epsilon - NTU Expression for a double-pipe counter flow heat exchanger. I know what I need to do the only problem I am having is:
I don't know how to algebraically go from
ln( \frac{\Delta T2}{\Delta T1} ) = -UA ( \frac{1}{Ch} + \frac{1}{Cc} )...
Hey everyone, I have a questions. I am trying to determine the most efficient way to heat pressurized air (35-40 psig, and a flow of 20-30 scfm) at an inlet temperature of 60F, to an exit temperature of 200F with minimal pressure lose. On site I have the availability of saturated steam at (50-80...
Homework Statement
Exhaust gasses flowing through a tubular heat exchanger at a rate of 0.3kg/s are cooled from 400C to 120C by water initially at 10C. Specific heat capacities of the exhaust gasses and water may be taken as 1.13 and 4.19 kJ/kg K respectively, and overall heat transfer...
Hello, I'm a third year chemical engineering student and i have to design a shell-and-tube heat exchanger.
My two fluids are:
- Tube side: Acetic acid at 8.90kg/s (from 303 to 343K).
- Shell side: Water at 2.5kg/s (from 350 to 310K).
This is my problem: When i want to find the correlation...
Hi!
I get the basics now, but this problem has got me stumped. I am trying to figure out where to start.
Homework Statement
In a heat exchanger, cold water flows through the tubes of the exchanger. It enters at 5.5°C, and leaves at 65°C. In the shell of the exchanger steam is being...
Hi I'm designing an air cooled heat exchanger but I'm not sure why calculations i need to do. Can anyone pls help on the steps needed to calculate or a template i can follow. I have the properties/details of the hot fluid but missng the air outlet temp and the velocity.
Thanks
Hi guys,
Can you please tell me the companies or manufacturers which have existing commercial louver-fin round-tube heat exchangers(aluminum or copper, or mixed material)?
I'm trying to google some, but cannot find any, could you please give me some brand names or products?
I'm...
Homework Statement
I'm given three temperatures and four pressures for a heat exchanger. I am also given the mass flow rate, which is the same for both the inlets and outlets. There is no heat transfer between the heat exchanger and the surroundings. My task is to find the fourth...
I'm working on a heat exchanger design, with water as the coolant. I'm running an analysis on this thing, and it looks like it's going to get hot. Like, 900F hot. So, of course this is going to be steam by the time it reaches the outlet. I'm really not a fluids kind of girl, but it's on me to...
I have an oil bath that has a jacketed heat exchanger I wish to use to heat another water bath.
The temperature of the oil bath is 100 C and the water bath temperature I require is 54 C. My question is will this be either too much heat or not enough.
My basic design is to use a thermistor...
Hi all...
can anyone help me thru these questions...
a) % of thinning allowance calculation of tubes while expansion
b) standard drwg. for tube to tube sheet weld joints
c) Inner Radius (Min.) calculation for floating Head Cover In AES Heat Exchanger
d) Selection criteria for...
Homework Statement
I have been asked to perform CFD simulations of a basic stainless steel cylindrical heat exchanger. I have to test a range of inlet temperatures and flow rates where external heat applied is constant.
I wish to perform basic hand calculation to verify my results by...
A customer of mine came to me asking for a price on a plate heat exchanger for water. The data he brought me was the following:
Primary side: 1,9 l/s and 12/16 C.
Sec. side: 2,4 l/s and 14/18 C.
I was just wondering if it is even possible to have different flows when the delta T is the...
Hi guys. Without going into too much detail. Basically I have a counter-flow heat exchanger problem where I need to find one of the outlets temps only given the inlet temps of each fluid. I have no idea how to do it though as I'm not given a value for over heat transfer coefficient (U) or...
Here in the NW most homes are or were heated by oil. The biggest cost of switching to gas (as geothermal is very expensive) is decommissioning the old buried oil tank, in many cases up to 675 gal. cap. I was pondering weather the old tank could be filled with a solution and somehow figure out...
Given the mass flow, Cp, temp of the inlet streams of both hot and cold streams.
As well as being given the inner pipe diametre of the double pipe heat exchanger.
Also knowing the setting is at counterflow and that the overall heat transfer coefficient and that the temp difference between the...
I need to design a concentric heat exchanger. I have steam flowing on the shell side( annular region of the heat exchanger) at 2 bar and water flowing on the inside. I am maintaining constant wall temperature with steam flow. How should i size the length of the heat exchanger and how should i...
In a closed loop with a heater and a fan cooled finned heat exchanger where water flows between the two, is it right to assume that the water will reach an equilibrium temperature?
If so, is there an equation that can get the equilibrium temperature?
The power of the heater and cooler, the...
Hi Guys newbie here.
Im trying to design a CHP system in which an engine with steady exhaust gas flow uses a heat exchanger to heat water for use around the home (central heating, washing water etc). The engine specifics are to be developed but i need to be able to size a heat exchanger so i...
I have 1,935,420 lbs/hr of process fluid entering all liquid at 168F. 38,000 lbs/hr boils, and the mixture exits at 190F. Total duty is 45,500,000 BTU/hr. Is there a way to calculate the liquid specific heat and the vapor specific heat with this information?
I have designed a heat exchanger of the double pipe hairpin variety and with 6" and 8" concentric tubes. The overall length is 90m therefore I need to connect nine 5m hairpins (10m total length) together but thinking about the practicality of it is it possible to connect this number in series...
If I calculate a heat exchanger effectiveness of 0.5 does this mean the heat exchanger is only 50% efficient in its transfer of thermal energy? Therefore if the capacity of the heat exchanger chosen is based on Q, then would you need to select a unit double this to account for only 0.5...
heat exchanger efiiciency??
I have done some design work calculations for a double pipe heat exchanger. I have the inlet and outlet temperatures and mass flow rates etc. I have calculated Q the heat transfer rate.
However I am confused with the idea of the thermal efficiency of the heat...
I have a problem whereby sludge of quantity 1000 kg/day is required to fill an anaerobic digester tank. The sludge enters at 20deg and is heated to 35deg. With refernece to this link http://books.google.co.uk/books?id=D...obic+digestion
it can be seen that if I have a quantity of 1000kg/day...
I have a problem whereby sludge of quantity 1000 kg/day is required to fill an anaerobic digester tank. The sludge enters at 20deg and is heated to 35deg. With refernece to this link http://books.google.co.uk/books?id=DwMWvTki7h8C&pg=PA197&dq=heat+required+to+heat+sludge+anaerobic+digestion"...
Im just generally reading through the notes for thermal design for a counterflow double pipe heat exchanger.
Is it possible for all temperatures inlets and outlets to be different for this type of flow arrangement?
What is confusing me is the temperature profile graph where Th2 appears to...
Homework Statement
A heat exchanger consists of two straight co-axial tubes, each of square cross-section. Liquid 1 enters at a rate m1 kg.s-1 at one end (x = 0) of the exchanger at temperature T10, and flows through the inner tube. Liquid 2 emerges at a rate m2 kg.s-1 at x = 0 at...
I'm in need of a specific heat exchanger (a quench cooler). It needs to cool fast (in seconds) and it needs to cool a lot (hundreds of degrees).
The coolant is water (making steam). The other side of the heat exchanger is a gas which can be compared to an exhaust gas: there are particles...