N5 Power Machines calorimeters

CALORIMETERS Definition or function: is used to determine the dryness fraction of the steam Methods of determining the dryness fraction: i. The barrel calorimeter ii. The separation calorimeter iii. Throttling calorimeter iv. The combined separating and throttling calorimeter Symbols Meaning MW Mass of cooling water in the calorimeter/ water(steam) condensed MS Mass of steam / water collected in the separator(water evaporated) 𝑃1 Pressure before throttling 𝑃2 Pressure after throttling CP Specific heat capacity of superheated steam X Sep Dryness fraction in separating calorimeter X thro Dryness fraction in the throttling calorimeter x Main Dryness fraction in the main line The pressure under the calorimeter; P 101.325 Br  M r  760 M water Useful formulas: X sep  xmain  xsep  xthro M water  M steam h f  xthrohfg  hg  cp steam tss  ts Possible questions: 1. A throttling calorimeter is used to determine the dryness fraction of the steam taken from the main where the pressure is 860 kPa and steam pressure after throttling is 140 kPa where the temperature is found to be 130 c Determine the dryness fraction of the steam if the specific heat capacity of the superheated steam is 2, 05 kJ/kg. c Downloaded from hlayiso.com

2. A throttling calorimeter is used to determine the dryness fraction of steam which is at a pressure of 260 kPa. The steam has the temperature of 91 c and a pressure of 7 000 kPa after throttling. The specific heat capacity of superheated steam is 2,1 kJ/kg. c Calculate the dryness fraction of the steam 3. The steam is throttled from a pressure of 760 kPa to a pressure of 400 kPa and a temperature of 150 c Calculate the dryness fraction of the steam 4. The dryness fraction of the steam is determined by using a separating calorimeter. For every 1,9 kg condensate which passes through the calorimeter, 0,36 kg of water is collected in the separator, determine the vapour of the steam 5. Determine the dryness fraction of the steam in the separating calorimeter if separator collect 5kg of water evaporated and 7 kg of steam condensed 6. A combined separating and throttling calorimeter was used to determine the dryness fraction of the steam in the mains. The following data was recorded: Pressure in the steam mains 1 800 kPa Pressure after throttling 120 kPa Temperature of the steam after throttling 126 c Mass of water condensed 2.1 kg Mass of water collected in the separator 0.52 kg Specific heat capacity of superheated steam 2.1 kJ/kg. C Calculate the dryness fraction of steam found in: 6.1. Separator calorimeter 6.2. Throttling calorimeter 6.3. Steam in the mainline 7. 4, 2% wet steam which is in a main line at a pressure of 2 MPa is passed through a separating and throttling calorimeter. The conditions in the throttling calorimeter are 140 c and 120 kPa. The specific heat capacity for superheated steam is 2,09 kJ/kg.K Calculate the dryness fraction as recorded in the separating calorimeter Downloaded from hlayiso.com

8. A dryness fraction test was conducted using a combined separating and throttling calorimeter. The steam main line had a pressure of 600 kPa. 0.18 kg of water was collected in the separating calorimeter and the following data was recorded at the throttling calorimeter: Steam condensed at exit: 9 kg Temperature 115 c Pressure 95 kg The specific heat capacity for superheated steam is 2, 1 kJ/kg.K Calculated each of the following: 8.1. The dryness fraction of the steam in the separating calorimeter 8.2. The dryness fraction of the steam in the throttling calorimeter 8.3. The dryness fraction of the steam in the main line 9. A dryness fraction test was used using a combined separating and throttling calorimeter. The pressure in the mains was 580 kPa and 0, 12 kg was collected in the separating calorimeter. The mass of steam condensed at the exit from the throttling calorimeter was 11, 2 kg. The manometer on the throttling calorimeter indicates a pressure of 120 kPa and temperature shown on the thermometer was 115 C take Cp for superheated steam as 2 kJ/kg.K Calculate the following dryness fractions of the steam in the: 9.1. Separating calorimeter 9.2. Throttling calorimeter 9.3. Mains 10. The following data was obtained from a combined separating and throttling calorimeter used to determine the dryness fraction of steam: Barometer reading at throttling 715 mm Hg Manometer reading at throttling 110 mm Hg Water condensed 6, 72 kg/min Water collected in the separator 0, 68 kg/min Steam pressure in the mains 960 kPa Steam temperature in the mains 125 C Specific heat capacity of superheated steam 2, 1 kJ/kg.K Calculate the following: 10.1. The dryness fraction of the steam after separating calorimeter 10.2. The pressure of the steam after throttling 10.3. The dryness fraction of the steam after throttling calorimeter Downloaded from hlayiso.com

10.4. The dryness fraction of the steam in the main line 11. A combined separating and throttling calorimeter was used to determine the calorimeter of the main line, and it was found to be 0, 889. The pressure in the main line was 980 kPa and the pressure after throttling was 140 kPa. The mass of steam condensed was 1, 9 kg and that of water (mass of steam) stored in the separator was 0, 15 kg while the S.H.C for superheated steam is 2, 01 kJ/kg. . Determine the following: 11.1. The dryness fraction of steam in the separating calorimeter 11.2. The dryness fraction of steam in the throttling calorimeter 11.3. The temperature of steam after throttling Downloaded from hlayiso.com