W003!70!005 Practical Training Instructions (1)

7/25/2019 W003!70!005 Practical Training Instructions (1)

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Practical Training Lab Instructions

Laboratory Technology and Bionics Thermodynamics Version 06_2016

Instructors Prof. Dr.-Ing. Joachim Gebel Dr. Nicholas Mockus

Tutors Karolin Beckmann Marian Rogge

Descr iption 1.1 Measurement of Pressure and Temperature

Purpose

There are numerous ways of measuring pressure and temperature. These utilizevarious physical processes to acquire pressure and temperature values. Current pressureand temperature sensors are either analog or digital. Different types of gauges,thermometers and electronic sensors will be discussed.

Significance

The underlying theories and significance of this experiment are described in detail bythe corresponding lab presentation.

Equipment

GUNT WL 202 Fundamentals of temperature measurement (incl. 6 thermometers)GUNT WL 203 Fundamentals of pressure measurementWater/IceInkTubing and SyringeHot plateDewar

Safety Precautions

Danger of electric shock!Prior to opening the switch cupboard, unplug the mains power plug.Protect the electrical system from damp, splashing water and condensation.


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Risk of burns on the hot plate and immersion heater!Do not touch the hot plate and immersion heater during operation. At the end of theexperiment, allow the heater to cool down before it is packed away.

Risk of poisoni ng due to mercury escaping from destroyed mercury thermometer!If a thermometer filled with mercury is destroyed: Observe the generally applicable safetyregulations for handling mercury.

Procedure

1. Using the syringe and tubing provided, attach the syringe to one side of the U-tube manometer.

2. Depress the syringe by 10mL. Note the change in water height on both sides ofthe manometer. Return the syringe plunger to its original position. Repeat theexperiment, this time withdrawing the syringe plunger by 10mL

3. Repeat this procedure for the inclined U-tube manometer.4. Using the syringe, test the positive and negative pressure Bourdon tubes by

depressing the plunger and retracting the plunger, respectively. Be careful, not toexceed the scale of the Bourdon tube, thereby risking damage to the gage.

5. Using the Bourdon tube calibration unit, observe the pressure reading as theweights are added to the oil column. Be sure to adjust the oil level so the weightsfloat on the oil.

6. For temperature experiments, heat a metal container of water using the hot plateto boiling. Concurrently add ice water to the Dewar.

7. Using the boiling water and ice water test the following thermometers;

-Mercury thermometer

-Gas pressure thermometer

-Bimetallic thermometer

-Pt 100 sensor

-NTC thermistor

-Type K thermocouple


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Descr iption 1.2 Marcet Boiler, Measurement of Boiling Curve

Purpose

The Marcet boiler demonstrates thecorrelation between steam pressure and heatingtemperature. An insulated steel vessel is filled witha defined quantity of water and sealed pressure-tight. The water is heated by an electric heater andbrought to the boil. To record the heating andsteam temperature the unit has a temperaturesensor element with an electronic evaluation unitand a digital display. The steam pressure occurringin the boiler during the experiments is calculatedand indicated by a mechanical manometer. Asafety valve prevents excess pressure build-up inthe boiler.

Significance

The underlying theories and significance of this experiment are described in detail bythe corresponding pre-lab presentation.

Equipment

GUNT WL 204 Marcet Boiler~2L Deionized WaterHigh temperature and pressure rated tubingTubing clamps1 large container filled with cooling water

Safety Precautions

Danger of explosion!Only remove the seal plug of the fill er opening when the boiler is ful ly depressurized!Removing the seal plug under pressure will result in uncontrolled explosive emission of hotsteam.


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Hot steam may be emitted!Do not touc h surfaces during operation!The safety valve may activate suddenly.Loud noise!Large quantities of hot steam will then be emitted.Never lean over the boiler while the experiment is in progress. Keep away from the boiler lidand the safety valve drain pipe.Exposed boiler surfaces and fittings become hot during operation!

Danger of electric shock!Prior to opening the switch cupboard, unplug the mains power plug.Work on the electrical system is only to be performed by suitably qualified personnel.Protect the electrical system from damp, splashing water and condensation.

Danger of fire!Do not place combustible materials in the vicinity of the boiler.

Procedure

1. The bench-top unit will be prepared as per the instruction manual by the

supervising instructor. For reference, this includes the following: The boiler unit is filled to the fill line with deionized water.

The head space inside the boiler is purged of air my boiling the water inside at 100C

with the purge valve opened.

The system is then sealed and allowed to cool to room temperature.

2. Switch on the unit at the master switch.

3. Switch on the heater and record the pressure and temperature up to 15bar.


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Description 2.1 Change of State of Gases

Purpose

The WL 102 table unit is for demonstrating Boyles law and

checking the state equation for ideal gases. It clearly shows therelationship between change in volume and the associated changein pressure of an enclosed gas. In another vessel, a fixed volumeof air can be heated to check the state equation and thecorresponding pressure change observed.

Significance

The underlying theories and significance of this experimentare described in detail by the corresponding lab presentation.

EquipmentGUNT WL 102 Change of States of Gases~3L Compressor Oil

Safety Precautions

Risk of bursting due to overpressure!Do not compress the air inside the cylinder to less than 1L volume.

Risk of burns at hot surf aces!Do not remove safety devices such as the guard.

Danger of electric shock!

Reaching into the open control cabinet can result in electric shocks.Disconnect from the mains supply before opening.


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NOTICE! Prior to compressing the air in the pressure cylinder, it is imperative to ensure that the

air discharge valve on the top of the pressure cylinder is closed. Risk of the escape and loss of sealing liquid. Fill in 3 to 3,5 liters oil max.

Procedure

Isothermal Compression and Expansion

1. Turn on the unit at the main switch.2. Open the air discharge valve on the lid of the cylinder to ensure the chamber is at

ambient pressure. Reclose the valve.3. Move the compressor selector switch to position A. Turn on the compressor for

~30seconds using the switch. Open the needle valve and allow the oil to fill thechamber until the oil level reaches the 1L mark on the vessel scale. Record the

pressure every 200mL. See Data table C1.4. On graph C1, plot the pressure verses volume. On the data table, calculate pressure

times the volume.5. Carefully open the air discharge valve on the lid of the pressure cylinder and release

the compressed air until ambient pressure is reached. Close the air discharge valveagain.

6. Move the selector switch to position B. Turn on the compressor for approximately30seconds. Open the needle valve and expand the gas volume until the 3L mark onthe vessel scale is reached. Record the pressure at every 200mL. See Data table C1.

7. Carefully open the air discharge valve on the lid of the pressure cylinder and allow air

to flow into pressure cylinder until ambient pressure is reached.8. On graph C2, plot the pressure verses volume. On the data table, calculate Pressuretimes the Volume.

Isochoric Heating and Cooling

1. Make sure that the cylinder is at ambient temperature.2. Open air discharge valve on the lid of the heatable cylinder and set the vessel to

ambient pressure. Close air discharge valve again.3. Set the required final temperature (60C) on the heating regulator using the arrow

keys. Switch on heater and operate as long as necessary until the final temperature is

reached. Record the pressure at approximately every 10. See Table C1.4. On graph C3, plot the pressure verses temperature. On the data table, calculate

Pressure divided by the Temperature.5. Open air discharge valve on the lid of the heatable cylinder and set the vessel to

ambient pressure. Close air discharge valve again. Switch off the heater.6. Leave the vessel to cool to ambient temperature. Record the pressure at

approximately every 10. See Table C1.7. On graph C3, plot the pressure verses temperature. On the data table, calculate

Pressure divided by the Temperature.


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Descr iption 2.2 Air Compressor

Purpose

The MT 140 Piston Compressor has one pistoncylinder assembly connected to a fly wheel. In order tooperate the fly wheel it is connected to an electric motor. Inthis setup, the piston is also connected to a storage tank,where pressurized air is stored.

Significance

The underlying theories and significance of thisexperiment are described in detail by the correspondinglab presentation.

Equipment

GUNT MT 140 Piston Compressor assemblyCompressor Oil

Safety Precautions

Danger of electric shock!Caution: high vo ltagePrior to opening the switch cupboard, unplug the mains power plug.

Danger of fire!Do not have open flame in the vicinity of the compressor oil.

Danger o f entanglement!Do not touch the motor belt or fly wheel while the machine is plugged in.


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Procedure

1. The piston assembly, motor, fly wheel, and storage tank will havbe been previouslyassembled. This will be discussed in depth by the instructor.

2. Connect the testing stage to the power supply.

3. Turn on the compressor. During intake vacuum is achieved in the piston assembly bychanging the piston head position with the fly wheel until the intake valve is open.

4. Afterward, intake air is compressed until the discharge valve is opened.

5. This process is repeated for the duration of the experiment.

6. To release the pressure in the storage tank, open the safety valve.

7. Students will record the pressure verses time for both a good installation of the piston

as well as a poor installation of the piston assembly.

8. Graph these values in the graph provided.

9. Concurrently, students will record the current consumption over time of the setup.

10. Graph these values in the graph provided

11. Once the experiment is concluded, the storage tank will be relieved of overpressureand the assembly will be disconnected from the power supply.


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Description 3.1 Steam Engine

Purpose

The ET 810 Single cylinder

Steam Engine demonstrates in aclear manner the function of a steampower plant using a scale model.The system contains all the keycomponents of a steam power plant:- Gas-heated boiler- Piston steam engine with generator- Condenser- Feed water tank and feed pump

Significance

The underlying theories and significance of this experiment are described in detail bythe corresponding lab presentation.

Equipment

GUNT ET 810 Single cylinder Steam EngineDeionized waterLubricating oilGraduated cylinderStopwatch

Safety Precautions

Risk of bursting due of overpressure!Do not allow the pressure inside the steam boiler to exceed 4 bar.

Risk of burns at hot surfaces.Do not remove safety devices or touch hot surfaces such as the propane flame or the

chimney.


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Danger of fire!Do not have open flame in the vicinity of the propane tank. Do not have flammable materialsin the vicinity of the steam boiler or flue gases.

Danger of electric shock!Caution: high voltagePrior to opening the switch cupboard, unplug the mains power plug.Protect the electrical system from damp, splashing water and condensation.

Procedure

1. Adjust gas flow rate to 60 L/h.

2. Adjust cooling water flow rate to 60 l/h (This may change to maintain the

temperature difference of cooling water inlet and outlet to 5-10C).

3. Manually start steam engine and leave to run at low speed without load.

4. Adjust steam valve such that a pressure of 1.2 bar is maintained.

5. Wait until the system has reached a steady state

6. Open condensate valve V5, pour away condensate collected and place

measuring container underneath and run the system for 5 minutes

7. Read and note all measured value.

8. Repeat reading every 5 min and ensure that the measured values change as little

as possible9. End experiment after 10 - 20 min.

10. Determine amount of condensate using the measuring container.


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Descr iption 3.2 Stirling Motor Purpose

In addition to the semester project, wepresent a larger scale version of a functioning

Stirling motor. This model is heated via heating coiland equipped with a pressure sensor and wheelsensor for measuring the volume inside the motor.

Significance

The Stilring Motor is an engine that outputswork by transfering heat into mechanical work. Thebasic principle of the Stirling Motor is the Stirlingcycle. Heat is introduced at the top of the Motor.The gas inside the cylinder is heated up and byisothermal expansion the piston is driven downperforming the first stroke of the motor. As the position of the piston changes, the cylindercomes into contact with the cooling zone where the gas is cooled down and by isothermalcompression the piston is driven upwards in a counterstroke. By the up- and down movmentof the piston the fly wheel is rotated.

Equipment

LD Didactic Hot Gas MotorPower supply for heat source3L cooling water/ Bucket/ Pump with Power supplyLD data collection unit w/ laptop

Safety Precautions

Danger o f entanglement!Be careful of the fly wheel and the volume measuring chord during operation.

Risk of burns at hot surf aces!Do not remove safety devices or touch hot surfaces such as the heating coil or itssurrounding casing.


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Danger of electric shock!Disconnect from the main supply before opening any voltage control unit. Be aware ofexposed connections to the heating unit or the pump.

Procedure 1. Fill the bucket with approx. 3L cooling water. Connect the water pump to the motor as

described and place the water pump inside the bucket. Adjust the power supply tocontrol the flow rate of cooling water.

2. Connect all measuring points to the data unit as per the instructions manual. Connect

the unit to a computer with the appropriate data collection software (CASSY Lab 2)

3. Turn on the power supply to the heating coil and adjust the voltage and current sothat the heating coil becomes glowing hot.

4. Manually kick start the motor by turning the fly wheel in the appropriate direction.

5. Wait until the system has reached a steady state

6. Run the Cassy lab software to collect a P-v Diagram of one cycle of the motor.

7. Integrate the area inside the graph.

8. Using the metal wheel magnetically attached to the fly wheel and a laser counter.Measure the frequency of the motor.

W003!70!005 Practical Training Instructions (1)

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