Experiment No

Experiment No. 5

TEST OF SMALL STEAM GENERATOR

Course Code: MEP510L2Program: BSME

Course Title: ME lab 3Date Performed:

Section: ME51FA2Date Submitted:

Leader: Enriquez, Vincent F.Instructor: Engr. Nelson D. Dela Pea Jr.

Members :

Erfe, Mark Leonard B.

Maramba, Jose Eric A.

Santos, Mhon Patrick A.

Baluyot, Jan Kenneth E.

1. Objective:

The activity aims to demonstrate the operation of steam generator.

2. Intended Learning Outcomes (ILOs):

The students shall be able to:

2.1 Explain fundamental principles of boiler capacity and its measurement.

2.2 Operate and test the boiler according to prescribed operating and test standards.

2.3 Collect and measure the required data for testing and calculations.

2.4 Use the proper reference materials, tables and charts in making an engineering representations and diagrams.

2.5 Develop professional work ethics, including precision, neatness, safety and ability to follow instruction.

3. Discussion:

Steam Generators are used in both fossil-and nuclear-fuel electric generating power plants. The most modern steam generators produce high-pressure (2400 to 3500 psia, 165 to 240 bar) superheated steam, the exception being pressurized-water reactor steam generators, which produce lower-pressure (1000 psia, 70 bar) saturated steam. The steam is invariably used in a Rankine cycle. Steam generators represent by far the greatest energy source for power plants in the world today. Boilers are generally classified as (1) firetube or (2) watertube, depending on what passes thru the tubes, fire tube if the hot gases pass thru the tubes and water tube if the water passes thru the tubes.

General Requirements in the operation of the steam generator:

Boiler water-level The first duty when taking over a boiler-room shift is to make certain the pipe, fittings and valves between the water glass and boiler are free and open by blowing down the water column and water glass and noting the promptness of the return of water to the glass. The most important rule The most important rule for the safe operation of boilers is to maintain the proper water-level at all times, and as constant a level as conditions will permit. If water is not visible in the water glass, shut the boiler off immediately until a safe water-level has been determined.Low-water and feedwater controls The low-water cutoff is the most important electrical/mechanical device on your boiler for maintaining a safe water-level. If a low-water condition develops, it could very well result in an overheating and explosion of your boiler. The low-water cutoff should be tested at least weekly.Low-water cutoff, evaporation test (steam boiler) While the boiler is in operation, shut off the feedwater pump and monitor the boiler water-level. The low-water cutoff should shut down the burner before the water level goes out of sight low; if the burner does not shut off, restart the feedwater pump before the water level goes out of sight low and immediately troubleshoot the low-water cutoff to determine the cause of failure. The boiler must be under constant attendance by a properly licensed engineer at all times during this test.Low-water cutoff, slow drain test (steam boiler) While the boiler is in operation, shut off the feedwater pump and slowly open the bottom blow valve to drain the water from the boiler. The low-water cutoff should shut down the burner before the water level goes out of sight low; if the burner does not shut off, restart the feedwater pump before the water level goes out of sight low and immediately troubleshoot the low-water cutoff to determine the cause of failure. The boiler must be under constant attendance by a properly licensed engineer at all times during this test.Firing Aside from the standpoint of economy, maintain the fire as uniformly as possible to avoid an excessive rate of combustion, undesirable variations in temperature and possible explosions. The destructive force in a boiler explosion is caused by the instant release of energy stored in the water as heat.Water gauges Keep all connections and valves clear. Test by blowing down the water glass and water column regularly. Gauge cocks or tri-cocks should also be blown regularly.Safety valves The safety valve is the most important valve on the boiler. Safety valves prevent dangerous over pressurization of the boiler. Safety valves are installed in case there is failure of pressure controls or other devices designed to control the firing rate. All safety valves should be kept free of debris by testing the safety valve regularly. This should be done when the steam pressure is at approximately 75 percent of the safety-valve set pressure. Safety and safety-relief valves on low-pressure boilers should be tested at least quarterly, this is in accordance with the National Board Inspection Code.Blow-down valves The concentration of solids in the boiler should be measured and the boiler blowndown at such intervals as necessary to maintain established limits. Blow-down valves are placed at the lowest point of the boiler for the purpose of blowing sediment or scale from the boiler. They should be maintained in good working order and are to be opened and closed carefully when used.Starting fires in a boiler Before starting fires in a cold boiler or restarting a fire that may have been accidentally extinguished, the entire fireside of the boiler must be thoroughly ventilated (purged) with the dampers open to remove unburned gases before attempting to relight the fire. Attempting to start a fire in a boiler with unburned gases is the most common cause of boiler furnace explosions.Boiler-room requirement A current proper engineers license and log shall be posted in the boiler room. It is the responsibility of the owner and the engineer to make sure the boiler is inspected annually.Hot-water systems These systems are equipped with expansion tanks for the expansion and contraction of the water as the temperature varies.Firing cycle, power burners The burner will start when the aquastat or pressuretrol calls for heat. The breeching damper will open and the draft fan will purge the combustion chamber. The main gas or oil valve will be energized when the pilot or ignition is proved.Repairs Any excessive overheating or burning, and any major repairs, must be reported to your boiler inspector.Classification of boilers High-pressure boilers are boilers operating at a steam or other vapor pressure in excess of 15 psig, or a water or other liquid boiler in which the pressure exceeds 160 psig, or has a temperature greater than 250 degrees Fahrenheit. Others are low-pressure boilers.

Cut-away view of fire- tube boiler

4. Materials and Equipment:

Mini steam boiler

Automation unit

Sling Psychrometer

Digital gas analyzer

Hydrometer

Graduated cylinder, (1000 ml)

Log sheets

Steam tables and charts

Personal protective equipment

Thermometers

5. Procedure:

The object of this test is to determine the efficiency, the evaporation per pound of fuel, and the cost of evaporation for a steam-boiler unit. The analysis of heat losses, or "heat balance," is also required (see ASME Test Code, Table S-2-b).

1. Ensure all group members have sufficient knowledge in properly handling and operating the instruments. Refer to the instructor and/or assigned technician when required.

2. Wear your personal protective equipment at all times.3. The team leader or test foreman should assign his team members' specific station to log test data with log sheets on hand and get the test under way as soon as possible. He should pay particular attention to the conditions prevailing at the beginning of the test and see that the same conditions prevail at the end of the test. This applies particularly to the fuel bed and fires, the water level, the rate of feeding water, the rate of steaming, and also to the steam pressure, the draft, and the temperature conditions.

4. Determine the air properties inside the boiler room at 10-minute intervals. Record and plot the data.5. Ensure enough supply of fuel and water supply. Fill the condensate tank by opening the entrance valve to a level above the minimum. For reference, mark this level on the sight glass.

6. If water is present in the boiler, mark the water level at the boiler sight glass for reference. Start the feed water pump and fill the boiler to level a little above the minimum on the sight glass (2/3 level is recommended).

7. Record the decrease in water level in the condensate tank sight glass. This will be used in computing the amount of water charge to the boiler. Record the feed water temperature.

8. When oil or gas fuel is used and the fuel is metered, the temperature and pressure of the fuel at the meters must be included in the data. Check the fuel oil level in the fuel tank. Mark this level as reference for fuel consumption.

9. Determine the specific gravity of the fuel and calculate its heating value according to ASME formula.10. Prepare and install the automation unit at the steam header. Set the data collection default at 10 minute intervals. Encode the Instructor and technician names as required. Monitor the boiler pressure closely. Bear in mind to start collecting data as soon as the boiler pressure reaches 40 psig.11. Set the boiler to 50 psig and 10 psig difference. Open the fuel line and ignite the burner. (Ask for assistance from instructor or technician in charge). Record the start-up time. Readings are to be taken at 10 minute intervals except when the instructor directs otherwise. Readings should always be taken in the same order or sequence, and the order of reading should be indicated on the log sheet. Each observer will prepare his own log sheet before the test is started, keep it in good form, sign and hand it to the test foreman at the end of the test. 12. Close the main steam valve to allow the pressure to build up. Closely monitor the pressure gauge. 13. When the pressure starts to develop, open the steam main valve to check if steam comes out of the steam line. This must be done for safety. Immediately stop firing the boiler if the steam main line is clogged and inform the instructor or technician in-charge.14. Close the steam line valve to allow boiler to develop minimum pressure. Record the steam pressure and temperature. Mark the level on the fuel tank and record the time.

15. The ASME Test Code recommends that a boiler test should preferably be:

For coal fired - 24 hours long when coal is used, either hand or stoker-fired. Where operating conditions do not permit a 24-hr test, 10 hours is prescribed as the minimum length of test, or what the combustion is less than 25 lbs of coal per square foot of grate surface per hour, the test should be continued until a total of 250 lbs per square foot of grate has been burned.

For pulverized coal - the minimum is reduced to 6 hours and for oil or gas fuel to 4 hours. Although the present test may not meet the Code requirements as to duration, it should be made as long as the time will permit. The main difficulties in the way of obtaining accuracy in short tests are those involved in securing the same fuel-bed conditions and the same water level and steaming rate at the end as at the beginning of the test.

In a short test, therefore, exceptional care should be exercised in regard to these details because of the heat-storage capacity of the setting, the boiler should be operated under test conditions for some time before the test is started. The Code specifies that this preliminary equalizing period shall be at least 3 hours.

16. Close the fuel oil line and switch off the burner.

17. Allow the steam pressure to drop to zero before closing the steam main valve.18. Upon completion of data gathering, stop the automation unit, making sure that data collected is stored in the hard drive. Print a hard copy. Data from the automation unit, when used in computation and diagram must be marked and cited accordingly.

6. Data and Results:

Form 5a. Steam Boiler Test - Preliminary Data

Location: ROOM A-201Kind of Boiler: Steam GeneratorManufacturer: Bruciatori BalturNumber of tubes:

31Diameter of tubes:

47.7 mmLength of tubes:

183 cmDiameter of Drum:

14 inLength of drum:

183 cmWater heating surface:

6.8558 m2Superheating Surface:

2.0444 m2Kind of fuel:

DieselForm 5b. Fuel Analysis

Baume gravity, deg (liquid fuel)

27.30oCHeating value at standard conditions

34.5 lbs/hrCost of fuel per kg44800 KJ/KG

Form 5c. Results of Steam Boiler Test

A. Average Pressure, Temperature

1. Steam Pressure, gage

200 Psig7. Feed water Temperature, C

102C

2. Barometer, mm-Hg.

7608. Flue gas Temperature, C

600C3. Steam Pressure, abs.

214.7 Psia9. Boiler Room Temperature,dry bulb, C

31C

4. Steam Temperature, C

130C

10. Boiler Room Temperature,wet bulb, C

29C

5. Steam Quality, %

43 %11. Moisture per kg air

0.1919 kg/s6. Degrees Superheat

8.62ocB. Hourly Quantities

12. Fuel as fired per hour

10.584 kg/hr15. Equivalent evaporation per hour

756.262513. Water evaporated per hour

N/A16. Units of evaporation per hour

N/A14. Factor of evaporation

1.0947C. Horsepower

17. Boiler Horsepower Developed

51.8934 Hp19. Boiler Efficiency

52.26 %18. Boiler Rated Horsepower

10 HpD. Evaporation

20. Actual Evaporation per kg fuel

N/A21. Equivalent Evaporation per kg fuel

71.4535 lb/hrE. Combustion Data, Flue Gas Analysis, Boiler Outlet

22. CO2, %

924. O2, %

N/A23. CO, %

N/A25. N2, %

N/AF. Cost of Evaporation

26. Cost of Fuel for 1000 kg actual evaporation

N/A28. Cost of Fuel for 1000 kg equivalent evaporation

N/ATime (mins)

Column Level (in)

Steam Pressure (Psi)

Steam Flowrate (Li/hr)

Boiler Pressure (Psi)

5

2.5

5

61

200

10

2.75

5

61

200

15

3.05

5

61

200

20

3.4

5

62

200

25

3.9

20

353

200

30

8.7

50

355

200

35

4

48

335

200

40

4.3

50

355

200

Useful Terminologies and Table:

1. Heating Surface shall consist of that portion of the surface exposed to both the gases being cooled and the fluid being heated at the same time, computed on the gas side.

2. Furnace Volume is the cubic space provided for the combustion of fuel before the products of combustion reach any heating surface.3. Equivalent Evaporation is the amount of water that would be evaporated from water at 212F to steam at 212F by the same amount of heat as was actually absorbed by the water and steam under operating conditions.4. Factor of Evaporation is the ratio of the heat actually absorbed by 1 lb of water and steam to 970.3 BTU. It is therefore the factor by which actual evaporation is multiplied to obtain "equivalent evaporation".5. Boiler Horsepower corresponds to an equivalent evaporation of 34.5 lbs of steam per hour.6. Rated Horsepower is usually determined on the basis of 10 square ft. of heating surface for water-tube boilers and 12 square ft. of heating surface for fire-tube boilers.7. Water Actually Evaporated is the water fed to the boiler less the water in the steam (corrected foe leaks and blow down, if any).8. Unit of Evaporation according to the Code is 1000 BTU absorbed by the steam per hour, and is therefore thousands of BTU absorbed per hour.It is to be noted that in accordance with the ASME Code, all calculations involving the fuel are carried out on the basis of 1 lb of fuel, whether the fuel be solid, liquid, or gas.

Table 5a. Typical Boiler Efficiencies

Type of Services

Fuel and Firing

CO2 in flue gas, %

Flue Gas Temperature, degrees F

Heat to Water and Steam, %

Central station, with economizer or air heater

Stoker

Pulverized coal

13.5

14.0

375

375

84

85

Isolated station, large industrial, institution, etc.

Stoker

Pulverized coal

Oil

Natural gas

12.0

13.0

11.0

9.0

500

500

500

500

77

80

80

80

Small power or heating plant

Stoker

Hand fired

Oil

Natural gas

11.0

9.0

10.0

8.0

600

600

600

600

73

63

75

75

Heating, large domestic plant

Stoker

Hand fired

Oil

Natural gas

7.0

6.0

6.0-7.5

4.6-6.0

450

450

350-450

300-450

63

55

75

65

7. Computation, Analysis and Interpretation of Data:

Baume = 140 / S.G @ 15.6 = 140 / 0.89 130

oBaume = 27.30oQh = 51716 8393.8 (S.G)2 = 51716 8393.8 (0.882)2Qh = 4487.66 kJ/kG

oSH = 147o Tsat @ 0.345

= 147 138.38oC

oSH = 8.62oC

m = pv = 1000 kg/m3(0.6909)

m=690.897 = m/t = 690.897 / 3600 s

ms = 0.1919 kg/s

Pdiesel = 882 kg/m3m=pv

= 882 (12)(1/1000)(1/3600)

M=0.00294 kg/s (3600/1)

mf=10.584 kg/hr

FE = hs hf / 2257 kj/ kg

= 2757.7 104.89 / 2257FE = 1.0947

EE = ms FE

= 0.1919 (1.0947)

EE = 756.2625 kg/hr

Developed Hp = ms (hs-hf) / 9.81 kN/hp

= 0.1919 (2757.7 104.89) / 9.81

Developed Hp = 51.8934 Hp

Boiler Rated Hp = HAS / m2 / hp

= 10.5961 / 1.1

Boiler Rated Hp = 10 Hp

Effy. = ms (hs hp) / mfQh

= 0.1919 (2757.7 104.89) / 0.00294(44825.66)

Effy. 52.66 %

Equivalent evap per level = EE / ms

= 756.2625 (2.2046 / 1) / 10.584(2.2046 / 1)

Equivalent evap per level = 71.4524 lb / lb fuelBased From the Data and results, the steam generated after 8 trials or 40mins is 50 psi at 130C temperature. 8. Conclusion and Recommendation:

OBJECTIVE: The activity aims to demonstrate the operation of steam generator. According to the Philippine Mechanical Code a Steam Generator is a closed vessel intended for use in heating water or for application of heat to generate steam or other vapor to be used externally from it.Generally this experiment will help us students understand the principle behind the steam boiler, how it operates and its auxiliary devices.

ILO:

2.1 Explain fundamental principles of boiler capacity and its measurement. The basicworking principle of a steam boileris simple. The boiler is essentially a closed vessel where water is stored inside, then fuel is burned in a furnace and when the fuel is burned hot gasses are produced. These hot gasses come in contact with the water inside the vessel where the heat of these hot gases transfer to the water and consequently producing steam in the boiler. Lastly, this steam is piped to the turbine which is the device that converts steam energy to electrical energy.2.2 Operate and test the boiler according to prescribed operating and test standards. Based on our observation while doing the experiment we have observed that the most important rule for safety in operating the boiler is that proper water level should be maintained at all times when running the steam boiler, when the water is not visible inside the water glass we have to shut down the boiler as it could result in hazardous situations.2.3 Collect and measure the required data for testing and calculations. On this experiment we have conducted 8 trials or 40 minutes on the boiler and the maximum pressure it produced is limited to 50 psi at 130C temperature.

2.4 Use the proper reference materials, tables and charts in making an engineering representations and diagrams. In this report we have used the Philippine mechanical code as a reference basis for standards in a steam boiler. Also we have included in this report charts that represents the pressure and temperature of the boiler.2.5 Develop professional work ethics, including precision, neatness, safety and ability to follow instruction.

When performing this experiment we have developed good work ethics by team work and good cooperation, precision and neatness while taking datas and most of all safety while doing the experiment.Conclusion:

According to the Philippine mechanical code a steam system comprises steam generation, distribution and utilization. It includes fuel, combustion, air, feed water, combustion system, steam quality and efficiency. The principle of a small steam boileris simple. Water is stored inside the boiler, then fuel is burned in a furnace and when the fuel is burned hot gasses are produced. These hot gasses come in contact with the water inside the vessel where the heat of these hot gases transfer to the water and consequently producing steam in the boiler. Lastly, this steam is piped to the turbine which is the device that converts steam energy to electrical energy. The most important rule in operating the small steam boiler is that proper water level should be maintained at all times when running the steam boiler, when the water is not visible inside the water glass we have to shut down the boiler as it could result in hazardous situations.

9. Assessment Rubric:

T I P - V P A A 0 5 4 D Revision Status/Date:0/2009 September 09TECHNOLOGICAL INSTITUTE OF THE PHILIPPINES

RUBRIC FOR LABORATORY PERFORMANCE

CRITERIA

BEGINNER

1

ACCEPTABLE

2

PROFICIENT

3

SCORE

Laboratory Skills

Manipulative Skills

Members do not demonstrate needed skills.

Members occasionally demonstrate needed skills.

Members always demonstrate needed skills.

Experimental Set-up

Members are unable to set-up the materials.

Members are able to set-up the materials with supervision.

Members are able to set-up the material with minimum supervision.

Process Skills

Members do not demonstrate targeted process skills.

Members occasionally demonstrate targeted process skills.

Members always demonstrate targeted process skills.

Safety Precautions

Members do not follow safety precautions.

Members follow safety precautions most of the time.

Members follow safety precautions at all times.

Work Habits

Time Management/Conduct of Experiment

Members do not finish on time with incomplete data.

Members finish on time with incomplete data.

Members finish ahead of time with complete data and time to revise data.

Cooperative and Teamwork

Members do not know their tasks and have no defined responsibilities. Group conflicts have to be settled by the teacher.

Members have defined responsibilities most of the time. Group conflicts are cooperatively managed most of the time.

Members are on tasks and have responsibilities at all times. Group conflicts are cooperatively managed at all times.

Neatness and Orderliness

Messy workplace during and after the experiment.

Clean and orderly workplace with occasional mess during and after the experiment.

Clean and orderly workplace at all times during and after the experiment.

Ability to do independent work

Members require supervision by the teacher.

Members require occasional supervision by the teacher.

Members do not need to be supervised by the teacher.

Other Comments/Observations:

TOTAL SCORE

RATING= x 100%

14