1. Experiment Outcomes At the end of the lab session student should be able: i. To define the properties of steam ii. To sketch the process of T-v and P-v diagram iii. To observe the phase changes of material iv. To know about the relationship between dryness fraction value and quantity of water 2. Theory A phase of substance can be defined as that part of a pure substance that consists of a single, homogenous aggregate of matter. The three common phases for H²O that are usually used are solid, liquid and steam. Molecular bonds are strongest in solids and weakness in steams. One reason is that molecules in solids are closely packed together, whereas in steams they are separated by great distances. The three phases of pure substances are: -
Transcript
1. Experiment Outcomes
At the end of the lab session student should be able:i. To define the properties of steam
ii. To sketch the process of T-v and P-v diagramiii. To observe the phase changes of materialiv. To know about the relationship between dryness fraction value and quantity of
water
2. Theory
A phase of substance can be defined as that part of a pure substance that consists of a single, homogenous aggregate of matter. The three common phases for H²O that are usually used are solid, liquid and steam.Molecular bonds are strongest in solids and weakness in steams. One reason is that molecules in solids are closely packed together, whereas in steams they are separated by great distances.
The three phases of pure substances are: -
PHASE CHANGE
STATE 1At this point, the steam and liquid are said to be saturated. As more heat is added, the liquid that was at saturation will start to vaporize until state 2. We speak of liquid in one of this condition as being compressed or subcooled liquid.
STATE 2The two-phase mixture of steam and liquid at state 2 has only one degree of freedom and as long as liquid is present, vaporization will continue at constant temperature. We speak at state 2 as being the saturated liquid state, which mean that all of the water in still liquid form, but ready to boil. As we continue to heat past the boiling point 2, a fundamental change occurs in the process. The temperature of the water no longer continues and to rise. In this part of the process, we speak of the water as being a saturated mixture (liquid + steam). This is also known as the quality region.
STATE 3After all the liquid is vaporized, only steam is present and the further addition of heat wil cause the temperature of steam to increase at constant system pressure. This is the saturated steam state. As we continue to heat the steam beyond state 3, the temperature of the steam against rises as we add energy.
STATE 4This state is called the superheated state, and the steam is said to be superheated steam.
3. Apparatus / Equipment i. Container with lid
ii. Stoveiii. Cube iceiv. Thermometerv. Measurement cylinder
4. Safety precaution i. Please make sure all the connection is tighten and no leaking.
ii. Please use cloth to open a container lidiii. Beware with the hot surfaceiv. Always work in a well-ventilated areav. Wash your hand with soap and water after performing all the experiment.
5. Procedure i. 600ml of cube ice are measured
ii. The cube ice are poured into the containeriii. The temperature of cube ice are measured before start heatingiv. See what happened to the cube ice texture and take the temperature after 3
minutes heat supplied.v. Heat are supplied until water is boiled (100˚C)
vi. Measured the volume of water in the container after 100% water had changed to steam every 5 minutes.
vii. The data are recorded in table along the process.viii. Discussion and conclusion are made.
i. When the heat is added to the liquid, what quantity is being added into the system.
i. The level of liquid decrease because of steamii. The temperature level increase
iii. After the liquid temperature reach to the boiling point, the bubble on the top of liquid produced
ii. Sketch this process in the temperature specific volume plane, that is the T-v plane.
iii. Sketch and label this process in the Pressure-specific volume, P-v relate to the theory of properties of steam.
iv. Calculate the value of dryness fraction at every stage.
8. Conclusion and Recommendation
i. Conclusion We learn how to defined the properties of steam. We also learn how to sketch the process diagram thought result we find, from experiment. We also learn about the relationship between dryness fraction value and quantities of water.
ii. Recommendation i. Put the lead top of beaker from initial of experiment until end of the
experiment.ii. The experiment area must covered from wind.
9. References
i. JM308 Engineering Laboratory lecturer.ii. Friend and classmate.
iii. Internet - http://ms.wikipedia.org/properties_of_pure_substanceiv. Internet - http://everythingmaths.co.za/science/grade-10/02-classification-of-
