What is Steam: Definition and 534 Discussions

Steam is water in the gas phase. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Steam that is saturated or superheated is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as water vapour condenses.
Water increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines, which are a sub-group of steam engines. Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80% of the world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure, it can create a steam explosion.

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  1. T

    Heat Transfer -- Rate of heat loss from a pipe with superheated steam

    Question - Four A pipe carrying superheated steam at 300 °C has an outside diameter of 120 mm and is lagged with two layers of insulating material. The first layer (adjacent to the outer pipe wall) is 25 mm thick and has a thermal conductivity of 0.072 W m-1 K-1. The second layer (covering the...
  2. A

    Using an IR Thermal Gun to check for steam passing valves

    Greetings I am asking about the reliability of using a thermal gun to check if there is passing downstream the valve. The fluid is either steam or air. Wouldn’t the pressure and temperature drop sharply downstream the valve if it is closed but passing ? again I am talking about air or steam...
  3. tito agiffaz efata

    Steam heating system transfers heat to a room (Thermodynamics)

    Homework Statement A steam heating system is used in winter season, The radiator of a steam heating system has a volume of 25 liters and is filled with superheated water vapor at 200 kPa and 200C. At this moment both the inlet and the exit valves to the radiator are closed. After a while it is...
  4. physea

    B Reading properties from a steam table

    Hello! I see this Steam table: It shows Vg but not Vf. It mentions some equations at the bottom. Does anyone know how much is Vf for 0.1bar?
  5. Al_Pa_Cone

    Steam and Gas Turbines - The Rankine Cycle

    <<Moved from another forum, thus no template filled out.>> I am having some trouble trying to relate a question given in my distance learning lessons to the equivelent question in my assignment. The assignement question is: 1(a) Superheated steam at a pressure of 40 bar and a temperature of...
  6. LonelyElectron

    Energy required to make 2.0 kg of steam

    Homework Statement A container holds 8.0 kg of water at 25 ˚C. How much energy must be added to the water to create 2.0 kg of steam? Homework Equations To be honest, not sure. SO MANY equations were given, and I don't know what is a variation of what. The Attempt at a Solution Q_total =...
  7. IAMJackal

    Analysis of DE Pool Filter as Steam Pressure Vessel

    Have built a 55 gallon DIY steamer from a DE pool filter. The pool filter is made from .06 inch stainless steel and was rated for an operating pressure of 50 PSI. As a pool filter, the vessel regularly operated at pressures of 10-15 PSI, and as much as 25-30 PSI when it needed cleaning. Have...
  8. M

    Isentropic Expansion Within a Steam Turbine System

    Homework Statement Steam is expanded from 90 bar, 412°C to 4.0 bar saturation in a high pressure turbine, after-which a certain percentage of the steam is bled off to a feed heater. The remaining steam is then expanded through a low pressure turbine to 1.0 bar and dryness fraction of 0.93. All...
  9. Tinokoloski

    B How to calculate rpm of an aeolipile

    Hi! I am making an aeolipile as a school project, and I was wondering if you could calculate the rpm. This is the basic principle of an aeolipile. You should be able to calculate the rotating velocity right? Knowing the mass and ignoring any resistance. But then you'll need the rotating...
  10. S

    Thermodynamics problem -- Steam cooled until it is just dry saturated

    "HOMEWORK" PROBLEM ORIGINALLY POSTED IN WRONG FORUM, SO NO TEMPLATE a rigid vessel of volume 1m^3 contains steam at 25 bar and 450c the vessel is cooled until the steam is just dry saturated calculate the mass in the vessel the final pressure and the heat rejected during the process? i know i...
  11. G

    Help on a thermodynamics problem -- Power from a steam turbine

    Homework Statement Homework Equations P=F*V, dU=Q-W?, W=m(h1-h2) The Attempt at a Solution I have the initial conditions and final conditions written out. For W=m(h1-h2), I have W=9.48(h1-h2). I am having problems with the h values, which can be found in the steam tables.
  12. S

    Saturated VapourPressure of Steam above Critical Temperature

    Hello all, I am not sure my question will totally make sense for those of you who now this topic well but as I am new to it I hope I can be forgiven. My problem is to work out how much water will condensate as a stream of moist air is expanded through a turbine. So far I was using Antoine's...
  13. Delta Force

    How Do Steam Plants Use Different Fuels?

    Historically it wasn't uncommon for boilers to be run on fuels different from those they were originally designed for. Ships were commonly converted from coal to petroleum after the 1910s, and for a period of time it was common to convert power plants from coal to petroleum as well. A common...
  14. P

    Answer for the Given on Steam Power Plant

    Steam Power Plant Questions
  15. Z

    Reversible Isothermal Expansion Steam

    Homework Statement 2kgs (total mass) of steam goes through a revesible isothermal expansion at 500 degrees celcius. During the expansion the pressure drops from 300 kpa to 200 kpa. What is the heat absorbed by the steam during this process? Homework Equations U=W and W=nrt ln(v2/v1) The...
  16. J

    This is the problem with STEAM (and STEM to a lesser extent)

    Apologies, but this is going to be a long rant to start a discussion. TL;DR: STEM (STEAM), like many forms of government and economics, are great in principle, but terrible when people get involved. At my high school we are required to participate in Professional Learning Communities...
  17. G

    Difference between Steam and Vacuum Distillation

    Hello Guys... I know this is simple but this two concepts confuse me a lot. Like in vacuum distillation Pressure is reduced to increase the difference in boiling point between two components and steam distillation is where steam is introduced in the mixture to reduce the vapor pressure. So what...
  18. D

    Thermodynamics Steam Question

    Homework Statement Steam at a pressure of 4 MPa and 400 C and flow rate of 10 kg/s is expanded in a turbine to a pressure of 10 kPa. If the isentropic efficiency of the turbine is 0.85 then the actual power produced by the turbine is? Homework Equations :[/B] ηt= (m(h1-h2))/(m(h1-h2s)) = (W...
  19. J

    How Much Steam Is Needed to Heat Water from 24°C to 90°C?

    Homework Statement The temperature of 100 gm of water is to be raised from 24°C to 90°C by adding steam to it .Calculate the mass of the steam required for this purpose . Homework Equations Latent heat of vaporisation of steam = 540 Cal/g The Attempt at a Solution [/B] Let 'm' be the mass...
  20. Const@ntine

    Thermodynamics: Steam is added to an ice cube

    Homework Statement Vapors of 100 C is added to an ice cube of 0 C. How much of the ice cube has melted and what's the final temperature if the masses of the steam and the ice cube are 10.0 g & 50.0 g respectively? Homework Equations Lw = 3.33 x 105 J/kg cw = 4186 J/kg*C Q = m*c*ΔΤ Q =...
  21. N

    Steam Condenser Not Working: Pressure & Temperature Issues

    The condensate drain from a steam condenser is expected to be about 50 deg C. It's only 38 deg C or so. There's a mix of steam and non condensable gases coming into the condenser. Its pressure seems slightly higher, being about 0.25 bar abs instead of 0.2 bar. What does it indicate? Also, no...
  22. W

    How Is Steam Quantity Converted to Water Volume?

    Hi there, Is there any method to calculate the amount of steam condensed to form water? Let's assume 1000 lbs of superheated steam at 4000C condensed to water at 450C. What will be the amount of water? I have calculated it through specific volume but it returns with a very minimum value.
  23. Prizzard

    I Crazy steam-hydraulic unit design

    I can't find equations for wall thickness or required temperature to generate steam at 6000psi. The goal here is a pressure vessel 'cylinder' 30" diameter, 36" long. It will be used to pump 42000psi hydraulics using a piston pump directly driven to a smaller series of pistons to allow the...
  24. N

    Steam locomotive Tornado hauling test train reaches 100 mph

  25. P

    Saturated steam inside a vortex tube

    We all are more or less familiar with the performance of vortex tubes regarding how they can make hot and cold flow by pressurised and/or air/gas at high speed. What I am wondering is the performance of saturated steam inside vortex tube. As for example, suppose we are using saturated steam at...
  26. P

    Steam Condensation: How Much Steam is Converted to Water at Constant Pressure?

    What I want to be clarified in this thread is about condensation of steam at constant pressure. Suppose Suppose an enclosed volume of size 1 m³ and it's filled with steam at 100°C and 1 barA pressure. Now, the container is connected to a chamber filled with dry air in such a way that the...
  27. electr

    Producing Dry Saturated Steam in a Fire Tube Boiler

    Homework Statement Dry saturated steam at a temperature of 180ºC is to be produced in a fire tube boiler from the cooling of 50 000 kg h–1 of flue gases from a pressurised combustion process. The gases enter the tubes of the boiler at 1600ºC and leave at 200ºC. The feed water is externally...
  28. Ali Ahmad

    Steam generation thermodynamics

    a cylindrical tank with volume V a volume of water is inside the tank and the rest is air now if coal combustion is releasing heat into the tank Qin and when the gauge reads a certain pressure "P", the valve is opened which allows steam to exit the boiler what's the mass flow rate of the steam?
  29. S

    Steam Power Plant Reheat Efficiency Calculation

    Homework Statement Homework Equations Heat added, Qa (This I'm not sure how since the steam passed through a reheater before it enters the HPT. That is what I understand based on the problem above) Work Net, Wnet Efficiency, Wnet/Qa Heat Rate, WP/EP (Not sure if that is the correct formula)...
  30. HethensEnd25

    Pressure change at the inlet of a steam turbine in a small electric power plant

    Homework Statement A steam turbine in a small electric power plant is designed to accept 4500 kg of steam at 60 bar and 500oC and exhaust the stem at 10 bar. Part C. In off-peak hours, the power output of the turbine in part a) (100% efficient) is decreased by adjusting a throttling valve...
  31. P

    Calorimetry: Finding mass of ice, water, steam left

    Homework Statement Given a copper calorimeter that has a mass of 446 grams containing 95 grams of ice at 0.0°C. If 35 grams of steam at 100.0°C and 1.00 atm pressure is added to the can, what is the final temperature of the can and its contents? At the final temperature, how many kilograms are...
  32. A

    Calculate steam raised per hour

    Homework Statement A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25ºC, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to generate 5...
  33. P

    Water spray to steam during compression in a hybrid diesel-steam engine

    I just have read about a new kind hybrid diesel-steam engine where water has been injected inside an internal combustion engine to improve efficiency. The basic principle behind the process is that water will soak up a large section of heat generated by burning the fuel and will turn into steam...
  34. L

    Heat Transfer. Ice and steam in a container (easy)

    Homework Statement "In a container of negligible mass, equal amounts (in weight) of ice at 0◦C and steam at 100◦C are mixed at the atmospheric pressure. Assuming no heat exchange with the surroundings, what is the temperature when the system reaches equilibrium? What are the fractions of...
  35. ElPimiento

    Equilibrium temperature of some ice and steam

    Homework Statement "A well-insulated bucket of negligible heat capacity contains 120 g of ice at 0°C. If 20 g of steam at 100°C is injected into the bucket, what is the final equilibrium temperature of the system?" Homework Equations $$Q_{fus} = m_{water}L_{fus}$$ $$Q_{vap} =...
  36. J

    Calculating Steam Flow in a Nuclear Power Plant Turbine System

    I have a thermodynamics question I'm having difficulty with... I have a steam generator heated by a 39MW nuclear reactor that powers two 4.5MW turbine generators. It produces dry saturated steam at 330psig, and enters the turbine at those conditions. It exits the turbine to a condenser...
  37. kumar1405

    Steam Generator Technology in Nuclear Power Plants

    hi every one , I need an information about the development of steam generator technology in nuclear power plants . please suggest me some websites or textbooks for reference . thank you in advance .
  38. S

    Calculating Mass Flow Rate of Steam

    Homework Statement If 5% of the heat available for steam production is lost to the atmosphere, determine the amount of steam raised per hour when the total flow of flue gases is 1400 kmol h-1. qmH = 1400 kmol h-1 Flue gas temperatures: Inlet = 1832°C Outlet = 300°C Water temperature: Inlet...
  39. G

    I Steam punk, Field of view including the eye

    Sorry if I missed the answer in my search. I expect I'm not use the correct terms. I want to design a Galilean/opera glasses style steampunk monical mounted to my reading glasses. I already have a simple lens that I can swing in front of my one eye. When using commercial eyeglass mounted...
  40. P

    Steam Turbine Efficiency and Steam Bleeding

    Homework Statement [/B] Steam is expanded from 90 bar, 412°C to 4.5 bar saturation in a high pressure turbine, after-which a certain percentage of the steam is bled off to a feed heater. The remaining steam is then expanded through a low pressure turbine to 1.0 bar and dryness fraction of 0.93...
  41. P

    A few questions regarding power generation by steam

    I have a few questions. Let's assume that we have steam at 200 barA pressure and 400°C temperature. If the temperature fluctuates but remains above the saturation temperature (365.746°C), does that affect power generation and turbine performance badly? Do the pressure too will vary with the...
  42. Adrianus

    What heat capacity is needed to evaporate water in oil

    Homework Statement In an industrial fryer is f.e. 400 kW. Heating capacity installed. The fryer may contain as much as 1.450 ltr of oil. I can fry 2.000 kg of chicken nuggets per hour in that. These products loose 7% of moisture/water in this process. That water can only escape from oil in gas...
  43. Tommyboyblitz

    Creating electricity from heat (without steam)

    I have a heat source in the form of a waste oil heater for a small workshop, i get around 200 degrees C from it and it warms the workshop up nicely. What i am wondering is is there a way i could produce enough electricty to run a small water pump from the excess heat? Something like a 12v pump...
  44. C

    Crower steam expansion stroke for two stroke/rotary engines

    I was interested in whether it might be possible to incorporate a steam expansion power stroke into a two stroke or a rotary engine. The difference would be that unlike the convention Crower six stroke cycle there would be compressed air in the combustion chamber, without some sort of valve...
  45. moenste

    Calculating Energy and Mass in Espresso Machine and Analyzing Cooling of Coffee

    Homework Statement (a) In an espresso coffee machine, steam at 100 °C is passed into milk to heat it. Calculate (i) the energy required to heat 150 g of milk from room temperature (20 °C) to 80 °C, (ii) the mass of steam condensed. (b) A student measures the temperature of the hot coffee as it...
  46. P

    Some questions about Steam Injector principle

    http://www.mekanizmalar.com/how-steam-injectors-work.html In the link above, the basics of steam injector is given. Steam Injector's don't have any moving parts and doesn't consume any energy by themselves. Still, it can be able to pressurise water and inject that to a high pressure Boiler by...
  47. G

    Boiler volume for specific steam turbine?

    New here, hope someone can help. I'm experimenting with a heat source for a steam turbine. I have the specs for the turbine and the necessary conditions for operation, but at this point in my design I need to figure out the volume of the actual boiler/reservoir. A direct answer or the right...
  48. P

    Power needed for saturated steam compression....

    Want to discuss a matter here. If steam remains saturated during compression, how to calculate the power consumption for that by using steam table. Suppose, saturated steam has been compressed from pressure level A to pressure level B and it remained saturated during and after compression. We...
  49. P

    Superheated steam and water together

    Lets start with an imaginary experiment. There is an enclosed container having a wide (i.e. having sufficient surface area) bowl filled with water at the bottom. The container is in vacuum and filled only with saturated steam at that specific temperature. Both water and steam are at the same...
  50. Dream Relics

    Steam engines -- A new idea, maybe....

    Why do we use water for steam engines? Why not something else? So, I have a question, or maybe it is an idea that i would like to share. So, sure, there are many finer points to the engineering of a steam turbine to make them work efficiently, and no doubt the designs have improved much since...
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