Heat exchanger Definition and 24 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.

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  1. Optymista93

    Cleaning of the finned tubes on gas cooler without disassembling

    Hi, I've been thinking about the solution for cleaning a water-cooled gas cooler and would love to hear some advice from the smarter people with more experience. Description - I will try to roughly explain the concept. Gas Cooler is used to decrease exhaust gas temperature. The exhaust gas...
  2. FEAnalyst

    Heat sink - calculating temperature at the base

    Hi, I've checked the literature but couldn't find any formulas or examples for this particular problem involving heat sink with straight fins: As you can see, I want to assume: - power at the bottom surface - convection (known ambient temperature and heat transfer coefficient) at the...
  3. S

    HVAC Attic to Pool Heat Exchange, will car radiator collect heat?

    My attic gets very hot even with the exhaust fan I installed. I would like to move than heat to my swimming pool. I currently have a FAFCO solar pool heater where the pool pump pumps water up onto my roof and thru the 12' long solar panel and down back into the pool. I would like to free up roof...
  4. M

    Condenser calculations - uncertainty

    A water cooled plate condenser, condensing refrigerant. Heat exchanger (condenser with plates) characteristics: Description symbol value value (converted) number of plates np 28 number of channels nc 27 number of water channels nwc 14 number of flowing channels for refrigerant...
  5. D

    Thermodynamic possiblity for outlet temperatures of heat exchanger

    I have a heat & mass balance diagram wherein there is a shell and tube heat exchanger to recover heat from hot exhaust gas using cold water. The exhaust gas inlet temperature is 120°C and the outlet is at 40°C. The inlet water temperature is 35°C while the outlet water temperature is at 50°C...
  6. Nikhil N

    Model developed from performance curves are dynamic models?

    I am trying to model a real heat exchanger in simulink. I don't have the geometry data. But I have UA curve with me. If I have developed the model with UA curve, will it be dynamic in nature?
  7. HumanistEngineer

    A Advanced Data Fitting - More than Simple Regressions

    Hello All, I want to improve myself in data fitting in order to derive new equations for the data from experimental results and/or performance analysis. I am an engineering researcher and since I found some out-of-world formulations derived from performance data, I need to learn this advanced...
  8. J

    Convection heat exchanger

    Hello guys, in the question attached, my understanding is that there is a heat transfer that heats the fluid from an initial at the input, to at the output. This heat transfer is via convection from walls of temperature . Firstly, . Because the walls are and the fluid is of a lower...
  9. Sheroff

    Saturation temperature?

    water is flowing in the closed looped pipe equipped with preheater. there are pressure and temperature gauges before the preheater and after the preheater. which pressure gauge should i use to know whether the outlet preheater temperature has reached the saturation temperature?
  10. L

    Heat exchanger and cooling towers design

    I was wondering all the assumptions I need to make regarding a design for a heat exchanger and cooling tower design from a IC engine testbed. Each engines average output is 55kW and the water jacket temperature is 80 degrees (C) and has to be cooled to 65 degrees (C). The ambient atmospheric...
  11. W

    Fluid Flow/Heat Transfer question struggle

    Homework Statement I would really appreciate if someone could help me out with this exercise in fluid flow/heat transfer ,because I really struggling with it.Below I am attaching photo of problem+table with values. Thank you in advance ! Homework Equations Question link:[/B]...
  12. Gary K

    Steam condensation

    Greetings, I'm preparing for an experiment on a modified Tesla Turbine design and will need to condense the exhaust steam rapidly in order to measure the pounds per hour of saturated steam that goes through the system. Incoming steam could be as high as 90 PSI through a 1" pipe. As the turbine...
  13. I

    Efficient water heating system

    I want to design a water heating system for a special type of pool. The system is open-loop, where input water at 10 C has to be heated to 15 C, and then enters the pool and is eventually exhausted out of the pool. The flow rate is about 100 litres/second (6000 litres/minute). Simply heating up...
  14. P

    How to size a heat exchanger?

    Lets assume an exchanger that is 100% efficient (no heat loss). Duty (Q) and LMTD is known. Your overall heat transfer coefficient (U) is dependent on your transfer coefficients on the shell and tube side, and the resistance of the pipe walls (we're going to ignore entrance effects and fouling)...
  15. T

    Spiral heat exchanger - pressure drop?

    Hi, I hope this is the right section. I'm trying to figure out a rough estimate of the pressure drop in a spiral heat exchanger. The fluids both being water. My guess it it would be in terms of the surface area of the inside of the heat exchanger, and the flow rate, but I can't seem to nail...
  16. enginej

    Heat exchangers for power plants

    I'm new to this forum, and would just like to say this is a very impressive site. My question is what is the best path way in school to design heat exchangers for power plants (more geared towards nuclear power plants.) I'm currently finishing my first year of school studying mechanical...
  17. M

    Simulation error messages solidworks - invalid goals

    I am running a simulation on a flat plate heat exchanger and the solver is coming up with some error messages. The first says that a vortex crosses the pressure opening and the second says that my heat transfer rate goals are invalid. How can I get the heat transfer goals to be valid as I need...
  18. M

    Flat plate heat exchanger - Hand calculations help

    I am designing a flat plate heat exchanger for a project and I am not sure where to start with the hand calculations, specifically the LMTD and E-NTU methods, also how to work out the parameters which i will need to complete these methods such as area and number of plates. My deadline is soon...
  19. J

    What is the effect of scaling down a heat exchanger?

    According to this article, it is beneficial to scale down heat exchangers due to the decreased distance the heat has to travel, and therefore the decreased thermal resistance and increased heat flow. "the best way to remove heat from a CPU is to minimize the distance heat must travel from a...
  20. N

    Heat Recovery from Boiler Exhaust Gases

    Homework Statement The exhaust gases from a natural gas-fired central heating boiler leave the boiler at a temperature of 70 deg C. The oxygen content of the exhaust gases is 9% by volume (dry). The rate of energy input (Gross calorific value) to the boiler from natural gas is 16kW. The gross...
  21. D

    Need some helps for a Heat Exchanger Optimization project

    Hello fellow PF members, My teammates and I are working on a project in our Heat Transfer class. It is extremely broad (open ended) and we are not very sure how we should get this project up and going. 1) Project description: We are given an Air Cooled Rankine Cycle. Cooling water, at 70 °C...
  22. P

    Refrigerator Compressors Already have Refrigerant?

    I am a little confused, because I know how refrigerators work with a refrigerant and a compressor and heat exchanges, and I am looking to build one myself, just wondering because I was looking for refrigerator compressors online to buy. Do they have an inlet for refrigerant or is the...
  23. S

    Co-current Heat Exchanger

    Homework Statement A hydraulic fluid initially at 60◦C is cooled to 35◦C using a co-current heat exchanger. Cooling water is available at 15◦C, which must not exceed 30◦C on leaving the heat exchanger. The flow rate of the hydraulic fluid is 1.5 kg/s, which has a specific heat of 5.2 J/gํ C...
  24. S

    How to design a radiator to dissipate heat generated by a 39 KW rotary engine?

    No separate coolant is used, instead lubricating oil to be used for both lubrication and cooling of engine. How to calculate radiator size, coolant flow rate?