Abstract:In this experiment we used the Marcet Boiler to investigate the temperature as the pressure is raised and compare the experimental values with the values in the properties table of water.The Marcet Boiler filled with water is to be healed first, until acertain absolute pressure reached. Then the heater will be turned off and will beallowed to cool down to itsinitial temperature. The increasing and decreasing temperature will be recorded for further use and calculation of the experiment

Objective:To investigate the temperature variation in a boiler as the pressure is increased.

Introduction:The figure below shows the type of marcet boiler which is used in this experiment. The main element of this boiler is the stainless steel steam boiler which has the capacity of 5 liters. The overflow valve ensures that the vessel is filled with the correct amount of water, which is 4 liters. The drain valve is used to drain the water in the vessel. Electric heater is used to heat the water. The manometer is fitted on the top of the boiler to measure the steam pressure. The temperature sensor is also connected to measure the temperature. The safety valve is used to prevent pressure to exceed 15 bar by automatically executing the process.Instruments:Marcet boiler, a manometer connected on the lid of the boiler, Temperature sensor, digital display for temperature, electric heater, a master switch and a secure tape.Procedure: Close the drain valve Remove the plug from the filter opening. Fit the tube to the overflow valve and open it before filling the water. Then fill the water in to the boiler so that it starts leaking from the overflow valve. Stop filling the water and close the overflow valve. Close the filter opening with the plug and secure it with the secure tape. Start the experiment by switching on the switch of the electric supply. At the same time start the stop watch. wait for the pressure to reach your required reading and record the time of reaching and the temperature . take the readings till the pressure rises to 15 bar. Then the system will automatically stop. After the heater is off take few measurements to observe the trend of cooling down.Results:Heating up ReadingsPsat (gage)Experimental(bar)Psat (abs)Experimental(bar)Time(s)TsatExperimentalC

Psat(abs)Properties table(bar)Tsat

c

0.51.5377109.81.5111.35

12411116.82120.21

1.52.5497120.62.5127.41

23557127.63133.52

2.53.5620133.83.5138.83

34671138.84143.61

45766146.75151.83

56851154.46158.83

67925160.47164.95

78996165.78170.41

891062170.79175.35

9101119174.810179.88

10111173179.011184.06

11121224182.812187.96

12131273186.313191.60

13141318189.614195.04

14151348192.615198.28

15161336195.216201.23

Cooling down readings

Psat (gage)Experimental(bar)Time(s)TsatC

12.5100191.15

10317181.8

7.5722170.6

51803153.6

Discussion: The experimental Tsat versus Tsat from the table graph shows that the experimental recorded readings and the readings from the table are approximately similar but not exactly same. The results from the properties table are more accurate than the experimental results.the reason for the errors in the reading can be due to difference in purity of water and due to recording the value later than it should be recorded.

The Tsat versus Psat graph shows that the pressure is directly proportional to the temperature.Tsat versus Time graph shows that temperature increases in short period of time.

The time taken to cool down and the time taken to heat up is not the same .The time taken to cool down is approximately double of the time taken to heat up.While heating the molecules join together and gain energy and move from themselves so the water take different time periods to increase the temperature, while in cooling they separate themselves in equal time so the time period of cooling down remains the same for the whole cooling procedure.Error Analysis: The error percentage should be around 10 - 20 % because there`s small difference between the actual and ideal value`s we got. Source of experiment error: Measurement reading accuracy Room temperature and pressure The stability of the materialsResolution to Experimental errors Avoid measurements readings errors. Take average of multiple readings Perform at room temperature

Conclusion:Fromtheexperiment,itisfoundfromthegraphandcalculation,temperature of a saturated steam is directly proportional to the pressure in equilibrium with water.Disgracing some negligible faults, this experiment can be consider successful, to improve the result of the experiment, it should be carried out at room temperature switching off all the air-conditions, and also by repeating the experiment and taking the average value. If some insulation were kept on theMarcet boiler to reduce heat loss, the experiment could be more accuratePrecaution to be taken :wear safety goggles and gloves to protect your body from any injury.The pressure should not exceed more than 15 bar so that the boiler does not explode.