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.
Ok bear with me as this sounds a bit bizarre, especially for a first post. For a while I have been thinking of how to take advantage of the fact that a black passive solar collector can collect low temp BTU's at low costs, but due to the low temperature it can not be utilized in a steam cycle...
I have a heat transfer question, I work in a plant and am doing a re-insulation project. If an unexposed steel steam pipe (k=47) of diameter 10 inches, maintains an internal temperature of 460F and is exposed to ambient air (70F) flowing at 5 mph across the pipe. Determine the heat loss per unit...
Hey all...So i have this project, to use any other liquid apart from water in a solar powered steam engine.
At the moment i am still in research phase, and have been reading on quite a few liquids although i have been concentrating on ethanol, as it is readily available and has a BP of 78...
Homework Statement
If a steam engine operates at half of its theoretical maximum efficiency (emax) and does work at a rate of W J/s, calculate how much heat is discharged per second.
Homework Equations
WMax = \epsilon_{Max}*Q_{H}
W = QH-QC
The Attempt at a Solution
W =...
Can somebody aid my understanding:
I am re-studying thermodynamics at the moment 6 years on from when I last studied it and could do with some clarification:
If at the inlet to a steam turbine the pressure is at say 150bar and 550 degrees then there will be a respective enthalpy which is a...
QUESTION:
Suppose the numerical value of 492 is assigned to the ice point temperature \thetaice=492.
a) Find the steam point temperature on this scale.
b) Calculate the temperature interval between the steam point and the ice point on
this scale.
SOLUTION a :
We know that the ratio...
In the event of grid failure islanding mode of operation of the electric generation unit is known as House load operation. Under this condition turbine generator produce only auxiliary load which is required to keep electric power plant unit alive. After restoration of grid the unit can be...
I've been looking around for any hint of this kind of thing, for a story I'm planning to write, and while I can ignore discrepencies between, say, actual history and events in my story, my inner scientist won't let me ignore this!
The situation is as follows; imagine an early industrial...
Such thing as a "steam panel" for generating energy?
Hi,
Sort of a hypothetical question here, though I suspect there's some real-world technology like this.
I was wondering about a possible way to generate energy using a panel that would catch steam, and use the temperature difference...
hi this is my first post on this forums hope every would help me here on this question
Homework Statement
outside vertical tube = 1m
outside diameter = 80mm exposed to saturated steam at atmosspharic preasure & is maintaiined at 50 c by the flow of cool water through the tube.
Rate...
Hey guys! Was wondering if someone could help me out. I'm doing a thermodynamics topic and have an issue explaining the following :
I conducted and experimental procedure involving a boiler apparatus. (Similar to this one >> http://www.armfield.co.uk/th3_datasheet.html" ) Now the idea was to...
A steam engine stove produces, say, 10 units of warmth, the second law states that not all warmth can be converted into work, so 8 units are converted into orderly energy, work, and 2 units aren't converted. Why did the entropy increase, since 10 units of warmth is more chaotic than 2?
A...
Homework Statement
A quantity of 100g of ice at 0°C and 50g steam at 100°C are added to a container that has 150g water at 30°C. What is the final temp of the container? Ignore the container itself in the calc. Homework Equations
Q=mc (change in T)
Q=mLThe Attempt at a Solution
I know how to...
Hi everyone,
I am looking into subject matter to use as my final year project at university.
The Tesla Turbine is something that I have recently looked into. I am interested to know the following...
In the Tesla Turbine, water is 'injected' and border interactions of the different molecules...
Hi fellow thinkers.
I need constuctive criticism on the following:-
Imagine a tube circling around into a closed loop - like a hoop. Inside the hoop is a ring of connected bar magnets all facing the same way. Pressurized steam is fed into the hoop - and exited in such a way as to spin the...
hello
i'm a first year student of mech eng...although its embarassing to admit, but i actually do not understand how a double acting steam engine functions. more specifically, i don't understand the inner-mechanism of the return-stroke. how does the piston come back to the top dead centre? is...
In Hal Clement's classic tale "Close to Critical" the planet Tenebra has an atmospheric pressure of 800 bar, 3 gee surface gravity, 100 hour rotation period and about 380 C surface temperature. The atmosphere is mostly water vapour and it condenses just enough for huge rain drops to form and...
Homework Statement
Steam initially at 120 oC is passed into 0.60 kg of water initially at 20 o C, and the total mass of water is just brought to the boil at 100C
What is the mass of steam that has condensed? Ignore the thermal capacity of the container and heat losses.
Homework...
1. How much heat is required to heat 5 kg. of water from 20C to steam at 100C?
I have no idea how to do this, i looked at some stuff online and i don't understand it, could someone explain how i can work throw this problem maybe even work throw it and explain the steps for me. I am more of...
Hi
Just wondering if I could have a bit of help on this question. Thanks in advance!
3) 100 g of steam at 150_C and 1 kg of water at 20_C are placed together inside
an insulated volume. The specic heat of steam is 2.02x10^3J kg_1K_1, that
of water is 4.19 x10^3 J kg_1K_1 and the latent...
To make steam, you add 5.8 X105J of heat to 0.2 kg of water with an initial temperature of 50oC.
(a) What amount of heat must be added to the water to bring its temperature to 100oC?
41860
(b) What amount of additional heat must be added to this 100oC water to convert it to steam...
Homework Statement
A perfectly insulated calorimeter cup(it niether gains nor loses energy) contains 300 grams of water at 10.0 degrees Celsius. If 15.0 grams of steam at 150 degrees Celsius are added to the water, what final equilibrium temp is reached?
Homework Equations...
Homework Statement
You have 50kg of steam at 100C, but no heat source to maintain it in that condition. You also have a heat resevoir at 0C. Suppose you operate a reversible heat engine with this system, so that the steam gradually condenses and cools until it reaches 0C. Calculate the...
Homework Statement
Wet steam at 0.5Mpa, quality 0.84 is to be heated to dry saturated steam. Determine the heat required if it is heated at constant volume and at constant pressure.
Homework Equations
h=hf +xhfg
u=uf +xufg
s=sf +xsfg
v=vf +xvfg
The Attempt at a Solution...
The question MUST be very simple! it is a 3 mark question, the first question of a first year Mech. Eng. Thermodynamics exam...
Homework Statement
A boiler produces wet steam at a pressure of 8.5 bar. A sample of the steam is passed through a throttling calorimeter. At the calorimeter exit, it...
Homework Statement
Steam in a piston-cylinder assembly undergoes a polytropic process, with n = 2. The initial state is p1 = 500lbf/in^2, v1 = 1.701 ft^3/lbm and u1 = 1363.3 BTU/lbm. IN the final state, u2 = 990,58 BTU/lbm. During the process, there is heat transfer from the steam of magnitude...
I am trying to wrap my head around what it would take to bring water vapor to superheated state. It seems that if you had a vapor stream and shot it with continuous laser energy (CO2 or other gas laser) you could instantly create a high quality steam. I am teetering between buying a diode...
I have a project for my sophomore design class to test the efficiency of a wobbler steam engine. I have heard people talk of using a dc motor and connecting it with a belt to the flywheel to see what voltage it produces but I don't know how to do that. In addtion, some have suggested to just...
I know I should get this, but I don't... So, I've been told that whenever I put some water into a kettle and then heat it to the boiling point, the steam coming from the kettle is hotter than the boiling water. Why is that?
And why is the temperature graph usually depicted as it is at...
Hello and Happy New Year to all,
I have found one formula which uses terms I hope you'll help me understand.
It is given in the attachment, and this is l
rhoW1 specific density [kg/m3] (corresponds to table value Pa = 1 bar, liquid phase)
rhoD1 specific density [kg/m3] (corresponds to table...
When hydrogen and oxygen burn they form steam, or H2O. I was thinking of quick and easy way to make steam would be by burning H2 gas and "air" in a simple rocket engine type burner at the pressure I needed the steam. Disregarding that the resulting flame is about at the top of the list for...
Hi posted the question/cry for help in a regular thread but thought it might fit in here as well.
Hello All,
I am currently trying to optimize a steam power plant cycle and I am stuck... What I am unable to figure out is how to use a Mollier chart/diagram in order to determine the amount of...
Homework Statement
- Is it possible to heat up water from 50 °C to 100 °C with saturated steam of 30 °C?
- If my hand is at 37 °C, is this 30 °C steam hot or cold when I touch it?
Homework Equations
Steam tables.
The Attempt at a Solution
I'm a bit confused here because there...
Following question is for concept only not an actual problem to solve.
Saturated steam is flowing in a 3" diameter pipe under a certain pressure (saturation pressure), temperature and velocity P ,T, v . The 3" diameter pipe expands suddenly to a 24" diameter pipe that is 10 feet long. The...
Hi All,
For a small steam turbine to generate power at a rate of 50 kW/h.
How many BTU's of heat required per hour, also water consumption per hour, how do you work this out?
1)Calculate the heat needed to change 2kg of ice at 0 degrees C to steam at 100 degrees C.
The attempt at a solution
2x334000=66800J
2x4200x100=840000J
2x2260000=4520000J
total=5426800J should be 6120000J somehow
2)An electric kettle produces 3000J of heat every second.It is filled...
Homework Statement
steam at 100C is added to ice at 0C find the amount of ice melted and the final temperature when the mass of steam is 10g and the mass of ice is 50g
Homework Equations
Q=mcdT
Q=ML
The Attempt at a Solution
Qmelt=MiciT+MiLf
=0.05(2090)(100C)+(0.05)(3.33x10^5)...
I'm stuck on the calculations concerning the sizing of the shell and tube condenser, about the equations to use..is the log mean temperature difference equation needed?
what is the best type of generator to use in a steam power plant?
What do people think about this
1. Put steam catapults on all airport runways (or perhaps use Linear Induction Motors)
2. Get the plane to accelerate all the way from the gate following a track, through to
launch, so acceleration for take off starts from 'go'. Apply an acceleration...
I wonder why water turbine (like in hydroelectric power plant) has, in most design, more then 90% efficiency when steam turbine around 30%.
In both cases we converting the pressure to work, so why such a difference in efficiency?
I have been working on an idea for a new energy source that I would like to get some input on. I took physics in college about 10 years ago, so I have a general understanding of the concepts, but I am definitely not an expert on thermodynamics.
Here is my idea:
1. Use a heat pump(ground...
I did thermodynamics I and II 50 yrs. ago so help me out here.
I note that high temperature and pressure steam is used in turbines and presumably the higher, the better the efficiency. My question is, is the temperature doing anything or is it only necessary to produce the high steam pressure...
Regarded oxygen separation from superheated steam using a multiple reactor tube
Superheated steam is passed through a black iron pipe set within a fire core heated to 1, 800'F. A carbon rod is inserted into the black pipe. A tap extends perpendicular to the black pipe where waste oil is...
Concerning super heated steam?
Please refer to u tube under joe pipe to see superheated tests
The Joe Pipe consists of a 2 x 24 inch iron pipe. Fan air is pumped in from the base and propane 4 inches up from the base.
To light, the mix is ignited outside of the pipe to generate...
I am trying to come up with a design for a steam power cycle with a 40% thermal efficiency under the conditions that all turbines have isentropic efficiencies of 85% and all pumps have isentropic efficiencies of 60%.
I have tried superheat, reheat, playing around with pressures/temperatures...
Hello!
There is an observation I have made when boiling water - amount of steam getting out of the kettle increases when the heating is turned off. Could anyone help to explain that?
The experiment goes like this. Take a kettle, start heating the water. The amount of the steam getting out...
Homework Statement
A well-insulated closed tank is of volume 70 m^3. Initially, it contains 25000 kg of water distributed between liquid and vapor phases at 30 deg C. Saturated steam at 11 bar is admitted to the tank until pressure reaches 7 bar. What mass of steam is added?
Homework...
I have made a Solar collector out of a 10' diameter satelight dish and lexan mirrors. I have a collector that converts water to steam ( 20lb propane tank) at a rather frightening rate I must add. Now i have a dilema. Where can I buy a turbine that i can bolt onto this scary steam source...
Well, I am studying for my engineering thermodynamics exam, and i don't seem to have written down some of the information about steam tables.
Im fairly confident using them, except i can't remember the exact formulas we use to get the numbers in between the numbers given. For example, i have...