Questions tagged [heat-exchanger]
The heat-exchanger tag has no usage guidance.
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Can I use a UPS in front of my A/C heat pump, to reduce surges in the house?
Hopefully this is on-topic here. I'm open if I should as on another SE site.
We have an air conditioner heat pump outside, typical to most homes with one. When it kicks on, many of the lights dim for ...
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Finding Intermediate Temperatures of 2-Stage Counter Current Heat Exchanger
I have a 2-stage counter current heat exchanger where I am given the initial temperatures for the cold and hot fluids (TH1 and TC1) as well as the final temperatures (TH3 and TC3). Additionally, The ...
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Advice needed on how to cool 50 ml liquid from 60 °C to 30 °C
In Short: I'm working on a project where we need to cool 50 ml of liquid from 60 °C to 30 °C or 20 °C. The liquid will be in a 150 ml copper container with an open top.
Due to the lack of skills in ...
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how to find final temperature of a fluid in an heat exchanger?
I have to find final temperature of water in an heat exchanger.
the heat exchanger must cool down air using water, meaning initial temperature of water must be cold,
initial temperature of air is 298....
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How can you determine the heat transfer area of a plate heat exchanger
Given the number of plates and channels (1-number of plates), as well as the width and length of each plate, it is true that the heat transfer area can be calculate by:
A = wL number_of_channels
Is ...
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What are important factors to considering from heat exchanger results?
Apart from an increase in mass flow relates to which results in an increase in heat transfer, what else is important to mention about heat exchanger results?
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Ultra-high temperature heat pump possibilities
How can I best transfer heat from space A [200ºC, 200 bar] to space B [1060ºC, 200 bar] using a heat pump style method? Both spaces are air filled.
Keeping in mind typical material limitations, a ...
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Cooling of two hot fluids
I have two hot fluids that need to be cooled. The first is the water loop that is used to cool the motor and power electronics. The second is an oil loop used to cool a gear box. Both these will be ...
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What would be the advantage of using Colburn j factor instead of h (heat transfer coefficient)
Why do researchers use the Colburn j factor vs. Re when presenting the thermal performances of a heat exchanger?
A graph of the heat transfer coefficient h vs. Re wouldn't be sufficient?
What are the ...
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Does wiring heat elements in parallel vs series at the same power affects the results?
I am designing an electric kiln just for fun and I found myself not knowing how to answer this scenarios.
The main constant is power. The final power must be the same in each case. My question is ...
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If 200kg/s mass flow rate of LNG is feasible in a heat exchanger?
Here is the situation: In a shell and tube condenser, the hot shell side is Pentane from 115°C to 36°C and the cold tube side is LNG at the temperature of -161℃ at the inlet of the heat exchanger. The ...
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Is it possible to do hot gas filtration through fluidized bed reactors
I am working on flue gas filtration and HCl gas is to be removed from the gas. I am wondering if a fluidized bed reactor could be used to filter the gas. The problem is, a furnace is used to provide ...
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Does it make sense to increase the thermal "dead weight" of a wood stove?
It is general practice to put a bucket of water on top of a wood stove to keep air humidity under control during the burning of the stove.
But, such a bucket is also bound to keep some more thermal ...
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Heat Transfer in a tubular reactor with constant jacket temperature - impossible solution?
I have received from my professor the following problem:
A first-order exothermic reaction A -> B takes place in a tubular reactor (typical PFR). The tube is cooled to a constant wall temperature $...
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Method for computing the pressure drop across a bank of tubes
I would like to determine the pressure drop of fluid in cross flow over a bank of tubes. (see figure 1).
Previously, I've used the correlation listed in "Fundamentals of Heat and Mass Transfer&...
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Predicting the behaviour of a boiler system if we modify temperatures
I am currently studying a boiler without many technical data.
Below a short description:
Fuel is put inside the boiler furnace. Primary (F1) and secondary air (F2) fans allow fresh air to go through ...
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Cooling system to maintain 0.5 °C at 95% humidity
I am looking for some guidance on a redneck cooling system.
I need to store seeding trees at a temperature just above freezing, and at a humidity of close to saturation.
I only need the system for ...
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How to design a fridge / freezer / air conditioner / heat pump?
I have this question / problem in my mind for an estimated of ~20 years. Obviously, my life does not depend on the solution, but the quality of the life of my brain might get improved :)
Shortly: How ...
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Nozzle inlet and outlet diameter for a shell and tube heat exchanger
Hi I have designed a shell and tube heat exchanger to cool octane and water. I have all the dimensions but I was unsure which equation to use to calculate the diameter for the inlet and outlet nozzles....
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Maximum rate of heat transfer in a balanced counter flow heat exchanger in NTU method
In effectiveness NTU method for heat exchangers, we have effectiveness of the heat exchanger defined as
$$\epsilon = \frac{Q_{actual}}{Q_{max}}$$
Where $$Q_{max} $$ is the maximum rate of heat ...
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In this scenario, if I continue to increase the length of heat exchanger how will the temperatures change?
Consider a counter flow double pipe heat exchanger inside which the cold fluid enters at 20 degrees Celsius and hot fluid enters at 100 degrees Celsius. Initially the length of the heat exchanger is ...
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Maximum rate of heat transfer in Effectiveness NTU method for a heat exchanger
The effectiveness NTU method is used for determining the heat transfer rate for a heat exchanger, with known inlet temperatures and surface area.
It makes use of effectiveness which is defined as
$$\...
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Arithmetic and Log mean temperatuer difference of a double pipe heat exchanger with parallel flow
Consider a double pipe parallel flow heat exchanger, the mean temperature difference in this case turns out to be logarithmic because the temperature profiles are exponential.
If we would have made ...
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How to model a condenser (heat exchanger) where both streams are two fluid mixtures?
As mentioned I would like to model a heat exchanger (using Python). In this case, the condenser/hx streams are both a mixture of O2 and N2
These are known for both streams:
Inlet temperature
Inlet ...
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Why does thermal conductivity of a pipe matter in a double pipe heat exchanger?
My understanding is that thermal conductivity is responsible for the time until something will heat up. For example, if you hold a copper bar over a candle it will quickly become hot at the other end. ...
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How are heat exchangers normally calculated?
Most of the calculations that I find in books are about calculating the heat transfer rate, which I'm not sure why I would care about. What I imagine is the case in a real world situation is that I ...
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In a shell and tube heat exchanger, does reducing flowrate affect the outlet temperatures?
Let's say I have 2 exchangers that are completely the same, only difference being that one of them has half the number of tubes. Also let's assume the coolant is the same and has the same inlet ...
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How to transfer air heat easily?
Assume two buildings, one which generates a lot of air heat inside due to electrical equipment running etc. The buildings are 20-25 meters apart. Some questions:
How can one easily transfer heater ...
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What is the fouling effect (in rate, foulant thickness) of sand inside tube side of a shell and tube heat exchanger?
I am working with RO reject which has high turbidity (mainly insoluble salts and also sand now). This is also my process stream and needs to go through a heat exchanger at 50-60C and flowing at 0.25m/...
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Does a photon impart energy on a surface (to raise its temp) if it goes THROUGH that surface?
Hi so I have this senior design project involving cooling human skin as it is irradiated by an infrared LED. Human skin not only is super absorbent to IR, but that IR goes THROUGH the thickness of it ...
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Furnace Combustion Air Properties
My house is heated by a condensing natural gas furnace that is rated as 92% efficient. It has the option to draw combustion air directly from outside. I know the main advantage of this is avoiding ...
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What temperature could be achieved when nitrogen is used as a refrigerant in the heatpump?
Well we all are familiar that nitrogen is used to achieve low temperature.
I was just wondering how can one determine the temprature that could be achieved when phase change of nitrogen is done from ...
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Heat transfer Calculation, for Cooling for an aluminium box
To go into more detail, I basically have a controller and its housing is basically an aluminium box that I need to add heat sinks to. But first I need to calculate how much heat is being dissipated by ...
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Heat Exchanger Design (Log Mean Temp Difference or Epsilon NTU Method)
I am trying to design two heat exchanger interfaces (shell and tube) that transfers heat to and from an intermediate heat pipe. The picture below gives a general idea of the problem I am trying to ...
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When is a heat exchanger worth it?
I am currently working on a huge industrial process for a student project and we need to transfer around 25MW of energy between dozens and dozens of streams, some larger and some smaller ones. Many ...
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How does energy recovery recuperator work
In a recuperator http://en.wikipedia.org/wiki/Recuperator, sensible heat can be transfered by thermal conduction through the plates, and latent heat can also be transfered when the high temperature ...
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Why Nusselt number for laminar flow in a pipe is independent of reynolds number
I understand that for fully developed flow inside a tube (with constant properties), Nusselt number doesn’t change in axial direction but it is surprising that it is also independent of Reynolds ...
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In a diesel engine, does more heat leave the engine through the tailpipe or the radiator?
Diesel exhaust is hot, and there's a lot of it.
Diesel radiators also get pretty hot.
In a typical diesel engine, which one is dissipating more heat?
EDIT: In response to a request for specificity ...
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Why do plate exchangers typically serve lower pressure fluids than shell and tube heat exchanger?
According to Wikipedia http://en.wikipedia.org/wiki/Heat_exchanger, plate exchangers typically serves lower pressure fluids than shell and tube heat exchanger, why?
Tubes in plate exchangers are ...
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How to periodically shut down a recirculating hot water solar thermal system
I am posed with a scenario where a hot water solar thermal system has been setup. The system comprises of a cold water tank, heating arrays and then a hot water tank. The system is closed loop and ...
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why not put the compressor right next to the evaporator?
the cold line from evaporator to compressor will gain tons of heat on a super hot day even with insulation. if they put the compressor right outside the evaporator, both of the long lines will be hot ...
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How can we dissipate the heat from a block of 10*10*3 mm with 100 degree Celsius without losing the portability of the block?
I have a Peltier's device of 10*10*3mm and the material is Bismuth Telluride. The hot side is 100 $^oC$ and I want to dissipate the heat, and at the same time, the device should be portable i.e. it ...
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Heat Exchangers
LMTD of a counter flow heat exchanger is 20°C and cold fluid enters at 20°c & hot fluid at 100°C, mass flow rate of cold fluid is twice that of mass flow rate of hot fluid. $C_p$ of hot fluid is ...
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Average Nusselt number or heat transfer coefficient to compare better heat transfer?
I'm simulating different arrays for cylinders in a simple cross flow heat exchanger (cylindrical pipes) as shown below:
Inlet temperate(300K) is constant and the cylinders are at constant temperature(...
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Heating hot air within a 2 inch tube
Background
So I am working on a project to where I am trying to heat up air within a 2 inch tube, with high air flow. I am using 2 inch tri clamp stainless steel tubes where I basically have a fan ...
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Are there any books which show how to design electrical coil heat exchangers?
I need to design an electrically powered gas heater, but i need to do so in detail. I'm looking for a guide similar to the shell and tube heat exchanger design guide in coulson and richardson's ...
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Search for comprehensive term for plants with heat generation with heat storage and operating states
My master thesis deals with systems with several operating states that generate heat and store it in a heat storage. Thereby I analyze combined heat and power plants with combustion engines, but also ...
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How to control precisely the wall temperature of a tubular reactor?
I have modelled a multi-tubular reactor performing a Fischer-Tropsch synthesis of alkanes and I was wondering about the stability of such a reactor. Even a very tiny deviation of the wall temperature ...
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Modelling reactor jacket with or without insulation, how to proceed?
I am currently trying to derive a model to help estimate as precisely as possible how much time can be saved by insulating the jacket of a reactor used for eating and cooling.
EDIT: I edited my post ...
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Calculating geothermal heat pump
So I need to calculate how big geothermal heat pumps I need for a building. Heat pump is used for heating and to heat used water.
If I know how many kW's are needed for heating the building and the ...
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