What is Coolant: Definition and 39 Discussions

A coolant is a substance, typically liquid or gas, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.
While the term "coolant" is commonly used in automotive and HVAC applications, in industrial processing heat transfer fluid is one technical term more often used in high temperature as well as low temperature manufacturing applications. The term also covers cutting fluids. Industrial cutting fluid has broadly classified as water-soluble coolant and neat cutting fluid. Water-soluble coolant is oil in water emulsion. It has varying oil content from nil oil (synthetic coolant).
This coolant can either keep its phase and stay liquid or gaseous, or can undergo a phase transition, with the latent heat adding to the cooling efficiency. The latter, when used to achieve below-ambient temperature, is more commonly known as refrigerant.

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  1. M

    Racing car coolant formula ideas

    Hey guys! So, I’m working on an engine coolant for track motor sports that can’t contain any glycols. I think a simple “water wetter” will work. A surfactant such as Tydol X-100 come to mind along with an anti foaming agent and aluminum corrosion inhibitor. I know there are commercial...
  2. nuclearsneke

    Exceeding the saturation temperature of coolant on the clad for PWR

    Hello there. I have been conducting a thermal calculation of a fuel assembly for KLT-40S reactor (a small modular PWR-like reactor installed at the floating nuclear power plant "Akademik Lomonosov" with electric power of 35 MWe.) and obtained some interesting results. It seems that cladding...
  3. A

    Coolant Mass Flow Rate Through Subchannel in Nuclear Fuel Assembly

    I am trying to find the mass flow rate of coolant through a channel within a hexagonal nuclear fuel assembly. I am given the specific heat of the fluid, the coolant inlet and outlet temperatures, the total power produced by a single fuel pin, the diameter of the fuel pin, the length of the fuel...
  4. M

    Basic understanding of Graphite-Water reactors

    From my reading about the Chernobyl reactor disaster, I am trying to get a basic understanding of a graphite-water reactor. From what I understand, the graphite acts as a neutron moderator - essentially slowing fast neutrons down to enable greater probability for an additional fusion reaction...
  5. kunalvanjare

    How can I achieve homogeneous in-line mixing of a Coolant with water?

    Hello guys, This is for a new product I am designing, which involves topping-up or refilling the liquid into a CNC Machine or Part Washer. I have to mix about a Litre of the chemical (alkaline.. pH in the range of 8-12) with about 50 Litres of water. The water will be fed under gravity through...
  6. kunalvanjare

    Designing an Automatic Coolant Monitoring System for CNC Machines

    Hey guys, I am designing a system that would monitor the coolant tanks of about 10 CNC machines through a centralized system consisting of valves, a pump & a refractometer. The system would be connected to the tanks through fixed piping in the plant. A pump would draw small amount of liquid...
  7. Delta Force

    Using Fuel as a Combustion Engine Coolant?

    Some jet and rocket engines use their own fuel as coolant. Hydrocarbons have even been used to cool electronics and nuclear reactors. Would it be viable for a combustion engine to use its own fuel as coolant instead of water or another liquid?
  8. O

    Radioactivity level in the coolant water

    Hi, Can anyone give me a source from which I can obtain the radioactivity level in the coolant water circulating in the primary circuit? Thanks in advance.
  9. Kashif

    MCNP Secondaries (PWR Coolant activation)

    I have to calculate the gammas produce due to oxygen activation in the coolant of PWR reactor core. the tally i used is F4 and FM.. but the problem is in core their are different cells within a cell. so how to specify the required cell . i have selected the whole core as a cell and then specify...
  10. InfernoxCJC

    Simplified Air-Conditioning Calculations

    Hello everyone! I am currently having some real issues estimating the power requirements for a concept vehicle's Air-Conditioning System, and I mean I've been going over this on and off for the better part of a fortnight. At this stage I feel like I have fried my brain and have no idea if I am...
  11. W

    Why is hydrogen added to BWR coolant but not PWR coolant?

    I know hydrogen gas is used in BWR coolant to counteract radiolysis and reduce the probability of localized corrosion. Why can't the same be done for PWR's?
  12. P

    Neutron flux in coolant and fuel pin in PWR

    In PWR, fast neutron produced from fission in fuel has been moderated into thermal neutron by the a series of collisiion with coolant,i.e. H2O. So the multi-group neutron flux in coolant and fuel pin has much diffenrce, e.g. the relative higher fast neutron in fuel pin and relative higher...
  13. T

    Sub Zero Temperature Chamber (around -50°C.)

    Hi Guys, Thanks for looking at the post firstly. I'm in the process of creating a chamber roughly around 30mm x 50mm x 70mm (W, L, H). The chamber will be used below the typical refrigeration temperature (-18°) of around -50°C. Please could you offer some advice where to start with this. 1...
  14. I

    Thermodynamics: why is freon a "good" coolant?

    I always thought that a working substance / coolant with a high heat capacity is better since it can take in more thermal energy. why then are some of the most common heat exchange fluid chemicals ones with low heat capacities? acetone and freon for example, are commonly used heat exchange...
  15. K

    HC & CO2 in Coolant: Detect Head Gasket Leaks?

    Hi, I want some information regarding HC and CO2 in Coolant (Car cooling system). As you know when the sealing (head gasket) between water jacket and combustion chamber fails, the engine smoke will enter cooling system which contains HC and CO2. I know that CO2 makes coolant acidic and...
  16. A

    Calculating Radiator & Coolant Flow Rate

    if anyone can please tell me is there any specific method for calculating radiator size and coolant flow rate for an engine...
  17. I

    Compressors in coolant systems

    I'm told the delay time (the time i turn down the thermostat and the time the AC kicks in) is a safety measure to let the coolant pressure equalize. I don't really understand why.
  18. Reza FMZ

    D2O Moderator/Coolant: Is Solidification Possible?

    Hello all, From those guys who worked with different materials especially reactor moderators and coolants, is it practicality possible to compress D2O between two metallic parts until it remains solid in room temperature? In otherwords wants to have D2O in solid at room temperature. Thanks in...
  19. J

    Engine Coolant Heat Dissipation Calculations

    Okay, I created this topic because the other one seem to get no responses?! I found this paper that was useful to me : http://people.bath.ac.uk/enscjb/airtex.pdf It mentions the figure 2.0 - 2.6 L/min/kW. Is this kW, the bhp? Question 1:For a Nissan Maxima (3.5 L engine), could I take this...
  20. J

    How Can You Model Coolant Cold-Side Temperature and Mass Flow Rate?

    Hi, I had been communicating with Chestermiller for the past many months and I modeled the exhaust gas flowing through the pipe of a car. Now, I had problems with the temperature sensor used, so this model couldn't be applied very well and its been a difficult time due to that. I have to...
  21. A

    Need Help with Coolant Flow Calculation for Engine Heat Rejection?

    could any guide me in Coolant Flow Calculation for finding heat rejection of engine through various system.
  22. D

    Mechanical Nuclear coolant pumps built on turbine to generator shaft?

    Hello, I'm new to this board. I have a engineering question about the coolant pumps used to maintain reactors. I have been studying the basics of a PWR. I notice the pumps are fed mostly by electricity. While I see the logic and efficiency of that..I am left wondering why the space on...
  23. V

    Coolant & Fridge Cooling Explained - Can Anyone Help?

    How does the cooling mechanism work in fridges? From what i have heard, it works by compressing frion and pushing it through a tube, because of the pressure and moving it through a tube it cools down. It still doesn't make sense can anyone help?
  24. Z

    Automotive Mechanical vs. electric coolant pumps

    Hi everyone, I am conducting a small research on how many manufacturers (if any) use electric water pumps in production vehicles. So far I found that many Audi models have auxiliary electric pumps which help the main mechanical one when needed (and maybe to run for some minute after turning the...
  25. T

    Automotive How Does Air Affect Engine Coolant Performance?

    Hello, my question is about air in engine cooling systems. Coolant is formulated to resist boiling, and furthermore kept under pressure to increase its boiling point. I think this is to control its phase. In other words we must prevent coolant from boiling (vaporizing) because vapor does...
  26. H

    Cold shutdown that doesn't require coolant circulation?

    "cold shutdown" that doesn't require coolant circulation? I was wondering what is preventing a plant being built that can be truly shut down and not require coolant circulation. Is it that efficiency would be reduced to unacceptable levels?
  27. S

    Control of coolant temperature in a nuclear reactor

    I am trying to build a model of CANDU reactor core using a software called DYMOLA.For this purpose,I am trying to figure out a mathematical relation between coolant temperature and Power developed in a reactor.I have the following questions: 1.What is the effect of increasing the neutron...
  28. M

    Coolant & Air Flow Rate: Finding the Car's Rates

    Does anyone have an idea about how to find the coolant flow rate in the car?? Any theoretical method.. And the volume flow rate of air through the radiator?
  29. D

    Design of IC engine coolant pump (centrifugal)

    Hello, I am to design a pump for the cooling circuit of a 4-stroke, 4-cylinder gasoline engine. The engine has already been designed. I am currently referring to Pump Handbook (McGraw Hill publications) and trying to get a hold of Centrifugal Pumps-Design & Application (Ross-Lobanoff). One...
  30. D

    Stability of fast neutron reactors with liquid metal coolant.

    Is my understanding correct that the short term stability of fast neutron liquid metal cooled reactors is based primarily on the thermal expansion of the core, while the Doppler coefficient is far less significant factor, as the Doppler coefficient primarily affects the low energy neutrons? (The...
  31. J

    I have a question about constant coolant temperature program

    I am trying to figure out exactly how the feedback works in this process. What I know so far when more power is needed •This greater loading causes more heat to be extracted from the heat exchanger, and for a short period of time, the heat capacity of the heat exchanger and coolant can...
  32. O

    Gas/liquid with coolant properties

    Greetings, I need to know which gas/liquid can absorb high amount of heat when passed through a hollow copper tube, heat is generated on the tube. The gas/liquid should not be conducting at ant point. If possible the conductor should absorb more heat than is generated at the tube.i.e...
  33. N

    Is a Pumpless Cooling System Possible?

    Hey All, Is there a cooling system similar to your car's radiator coolant system that does require a fluid pump? I am looking for a simple system that will behave similar to such a system, but the difference in heat ( or resulting pressure) from hot source to cold area (which would be...
  34. M

    Light water coolant is at a supercritical pressure at 25MP

    I don't get it.I found out that light water coolant is at a supercritical pressure at 25MPa.The boiling phenomenon disappears at supercritical pressure but the specific heat shows a peak around the pseudo-critical temperature.There is no phase change from liquid to gas,so the coolant flow in...
  35. S

    Small Claims Case - Coolant Flush/Water Pressure Question

    Hello, I know that this is a auto mechanical issue but I hope this is a question that someone here can shed some light on for me. It involves water pressure. I recently had my coolant flushed at an Oil Changer shop in the bay area. The kid hooked up a "Coolant Changer" machine to my...
  36. P

    Navy Nuclear Reactor Coolant: Lithium Hydride & Water

    First Post :smile: What type of Coolant is currently used in Navy Nuclear reactors? I have searched on google and came up with 2 things, Lithium Hydride and Pure Water pressurized to 2200+ PSI. Is there anything else used as a coolant? Thanks
  37. S

    Which is a better coolant for a car: methanol or water?

    What exactly is a coolant? Which is a better coolant for a car: methanol or water? Why? Thank you for your time! :wink:
  38. GreyBeaver

    Strange Coolant Device: Info & Where to Find It

    I've heard about some small chip of some kind that has termendous cooling power when a current is run through it. Apparently it is a high efficiency alternative to a large refrigerator when it is kept in a small, enclosed area. It's equivalent to something like 10 bags of ice or something, I...
  39. M

    Coolant Systems For Armor Design: Efficiency & Performance

    i am designing an armor in my head (along with hundreds of other things) and i want to know specifics about cooling systems. I've decided on a coolant system pumped by feet/arm movements/etc but i need to know: how effective are such systems? specifically, how long would they last, how cold can...