Be project - PRDS (Pressure Reducing And Desuperheater Station)
1. SIES GRADUATE SCHOOL OF TECHNOLOGY
DEPARTMENT OF MECHANICAL ENGINEERING
GROUP NUMBER -6
DESIGN OF PRESSURE REDUCING AND DESUPERHEATER STATION
GROUP MEMBERS
CHARIT GEDDAM - 218A6064
NIKHILESH MANE - 218A6067
PRATHMESH MOHOL - 218A6068
UMESH POL - 218A6077
GUIDED BY
PROF. PRAJAKTA KANE
2020-21
2. CONTENTS
➔ INTRODUCTION
➔ PROBLEM DEFINITION
➔ OBJECTIVE
➔ LITERATURE REVIEW
➔ METHODOLOGY
➔ DESIGN
➔ LAYOUT
➔ COMPONENTS
➔ FINAL OBSERVATION
➔ REFERENCES
3. INTRODUCTION
Project title -
Company name -
Company Guide -
Company Address -
Company About -
Design of Pressure reducing and desuperheater station.
Bajaj Power Equipment Pvt. LTD.
Mr. Pradip Nagawade (Design Manager)
Survey No : 227/3, Nimblak By-pass, M.I.D.C., (M.S.) India, Ahmednagar - 414111.
Bajaj Power Equipments Pvt. Ltd., (BPEPL) is an IBR approved, ISO 9001: 2008 certified company.
BPEPL is engaged in design, engineering, manufacturing, supply, erection and commissioning of high
pressure multi-fuel boiler for co-generation plant and power plant in India & around the globe.
4. Desuperheater
The Desuperheaters are used to reduce the temperature of steam generated by high pressure/high temperature boilers to levels required in
process operations.
The primary function of a desuperheater is to lower the temperature of superheated steam or other vapors by bringing in contact with the
coolant.
Inline direct desuperheater.
coolant
6. Classification of desuperheater
Venturi Desuperheater Annular Venturi Desuperheater Nozzle (single and multi nozzle) Surface Absorption Desuperheater
Multi Nozzle Inline Desuperheater
7. Classification of desuperheater
Venturi Desuperheater Annular Venturi Desuperheater Nozzle (single and multi nozzle) Surface Absorption Desuperheater
Multi Nozzle Inline Desuperheater
The multi nozzle desuperheater has several nozzles (orifices of same diameter).
8. Classification of desuperheater
Venturi Desuperheater Annular Venturi Desuperheater Nozzle (single and multi nozzle) Surface Absorption Desuperheater
Multi Nozzle Inline Desuperheater
The multi nozzle desuperheater has several nozzles (orifices of same diameter).
Advantages
➢ Higher pressure drop
➢ Higher mixing rate
➢ High atomisation
➢ No problem of critical point occurrence
9. PROBLEM DEFINITION
Design and manufacturing of Pressure Reducing And Desuperheater Station (PRDS) as per the Industrial requirements
Purpose:
The steam from the boiler after expansion in turbine is exhausted to the atmosphere.
The temperature of the exhaust steam from boiler is high hence cannot be used directly for an application.
This steam can be used for various applications if the steam is brought to required condition.
This process of bringing the steam to required level can be done by Desuperheater.
10. OBJECTIVE
● To design an effective and compact inline desuperheater
● To design safe and efficient pressure reducing station
● To manufacture the Desuperheater
● To analyze the operation of Desuperheater
11. LITERATURE REVIEW
SR
No
Paper Title Year of publication & name
of the Journal
Findings
1 Desuperheater for waste heat January 1983
International Journal of
Refrigeration
● Compacting design procedure
2 Desuperheater Selection and Optimization Academia
Kristin Donahue
● Parameters affecting the design
● Desuperheater material selection parameters
● Styles of desuperheater
3 Advances in Desuperheating Technology for
combine performance of CCPP
January 2005
Research gate
● Approach to Desuperheating
● New developments for reliable prediction of desuperheating
4 Mechanistic modelling of desuperheater
performance
May 1996
Elsevier
● Prediction of desuperheater
● Analytics tool for desuperheater
● Behavioural analysis of steam in the desuperheater.
5
Experimental Increase in the Efficiency of a
Cooling Circuit Using a Desuperheater
24 February 2016
ResearchGate
● Experimental cooling technique using Desuperheater
● Practical application of desuperheater in the circuit and the effect in the
electricity usage, behaviour of desuperheater
13. 1. Analysis of steam properties:
The steam properties plays major role in designing. In this we analyze the exhaust steam properties (boiler outlet) and the steam properties
required at the outlet of desuperheater.
14. 1. Analysis of steam properties:
The steam properties plays major role in designing. In this we analyze the exhaust steam properties (boiler outlet) and the steam properties
required at the outlet of desuperheater.
2. Selection of valves and PRDS layout:
In this we calculated the parameters and prepared the design sheet according the calculation results. The step included the selection of type
and material for valves, the pipe diameters and length, strainer, sensors and desuperheater.
15. 1. Analysis of steam properties:
The steam properties plays major role in designing. In this we analyze the exhaust steam properties (boiler outlet) and the steam properties
required at the outlet of desuperheater.
2. Selection of valves and PRDS layout:
In this we calculated the parameters and prepared the design sheet according the calculation results. The step included the selection of type
and material for valves, the pipe diameters and length, strainer, sensors and desuperheater.
3. Design and manufacturing of Desuperheater:
The step included the nozzle calculation (orifice diameter, number of orifice, location), location of desuperheater and length.
16. 1. Analysis of steam properties:
The steam properties plays major role in designing. In this we analyze the exhaust steam properties (boiler outlet) and the steam properties
required at the outlet of desuperheater.
2. Selection of valves and PRDS layout:
In this we calculated the parameters and prepared the design sheet according the calculation results. The step included the selection of type
and material for valves, the pipe diameters and length, strainer, sensors and desuperheater
3. Design and manufacturing of Desuperheater:
The step included the nozzle calculation (orifice diameter, number of orifice, location), location of desuperheater and length.
4. Installation and analysis:
After manufacturing the PRDS was installed at site. The desuperheater observations noted and a final analysis report consisting of
comparison between the actual and theoretical output of Desuperheater was prepared.
19. STEPS FOR CALCULATION
1) Calculate the mass flow rate required at the outlet of desuperheater
2) Calculate the steam pipe diameter
3) Calculate the water (coolant) pipe diameter.
4) Check the steam pipe & water for load
5) Calculation of nozzle parameters i.e. diameter, height, no of holes.
6) Selection of PRDS Layout i.e valves, strainer, filter, gauge, temperature sensor, pid, flange.
20. Given data:
Steam Inlet
Pressure (Psi) = 45 Kg/cm2
= 44.13 bar
Temperature (Tsi) = 425 c
Mass (Msi) = 10000 Kg/hr
Velocity = 39 m/s
Enthalpy Hsi = 3273.98 KJ/Kg (at 400 c)
Water (coolant)
Pressure (Pwi) = 60 Kg/cm2
Temperature (Twi)= 105 c
Mass (Mwi) = Not Known
Velocity = 1.3 m/s
Enthalpy (Hwi)= 444.48 KJ / Kg (at 105 c)
Steam Outlet
Pressure (Pso) = 4 Kg/cm2
= 3.96 bar
Temperature (Tso) = 170 c
Mass (Mso) = Msi + Mwi
Enthalpy (Hso) = 2797.631 KJ/Kg
(All enthalpy selected from steam table)
21. Heat and Mass balance across desuperheater
Heat Inlet = Heat Outlet
Msi * Hsi + Mwi * Hwi = Mso * Hso
Mso = Msi + Mwi
After solving these equations, we get.
Mwi = [Hso - Hsi] Msi
[Hwi - Hso]
Mwi = [ 2797.63 - 3273.98] *10
[444.48 - 2797.63]
= 2.024 ton/hr = 2100 kg/hr
Mso = Msi + Mwi
= 10000 + 2100
= 12100 kg/hr
Sizing of steam Pipe
Msi = A * V
S.V
Where,
Msi = Mass flow rate of steam at inlet = 2.777 Kg/sec
A = Area of pipe [ (π/4) * ds2
]
V = Velocity of steam
S.V = Specific volume of steam
= 0.069214 m^3/kg ----( from steam table )
2.777 = π * ds2
* 39
4 * 0.069214
ds^2 = 0.2777 * 4 * 0.069214
π * 39
ds = 0.7921 m = 0.08m = 80mm
The diameter of the pipe should be 80mm
22. Sizing of water Pipe
Msw = A * V
S.V
Where,
Msw = Mass of water (flow rate) = 2100 Kg/hr = 0.5833 Kg/sec
A = Area of pipe [ (π/4) * dw2
]
V = Velocity of water = 1.3 m/s
S.V = Specific volume = 0.069214 m3
/kg----- ( from steam table )
0.5833 = π * dw2
* 1.3
4 * 0.00104
dw2
= 0.5833 * 4 * 0.00104
π * 1.3
dw = 0.02437 m = 25mm
The diameter of the pipe should be 25mm
23. Material of steam pipe = A106 Gr B
Schedule = 40
Thickness = 5.49 mm
Allowable stress = 55.8 Mpa = 55.8 N/mm2
(From ASME II Section D)
ASME B36.10/19M 3” NPS Sch-STD
Material of water pipe = A106 Gr B
Schedule = 40
Thickness = 3.38 mm
Allowable stress = 126 Mpa = 126 N/mm2
(From ASME II Section D)
ASME B36.10/19M 1” NPS Sch-STD
24. Water pipe safety calculation
Hoops stress (σh) =Pdw
2t
P = 63*10^5 N/m2
d = 0.025 m
t = 0.0038 m
σh = 63*105
*0.025
2*0.00338
σh = 23.29 * 10^6 N/m^2
σh = 23 N/mm^2
σh allowable (126 N/mm2
)> σh calculated (23 N/mm2
)
Design is safe under these condition
Steam pipe safety calculation
Hoop stress (σh) = Pds
2t
P = 44.13*10^5 N/m2
d = 0.08 m
t = 0.0392 m
σh = 44.13*105
*0.08
2*0.0392
σh = 45.14*10^6 N/m^2
σh = 45 N/mm^2
σh allowable (55.8 N/mm2
) > σh calculated (45 N/mm2
)
Design is safe under these condition
25. Solid Full Cone Spray Nozzle
Full cone nozzle form a complete coverage in a round or square shaped area. It provides an uniform spray distribution of medium to large
size drops resulting from the vane design which features large flow passage and control characteristics.
Spray nozzle
Spray representation Nozzle (Top view)
26. Nozzle Dimension:
Type:- Full Cone Nozzle
Pressure:- 800 psi (55.15 Bar)
Velocity:- 10 m/s ( after spraying i.e. Droplet Velocity)
Droplet Size :- 100-300 microns (i.e very fine)
Nozzle Hole:- 1.52 mm
Nozzle Capacity (each):- 2.38 Gpm for 800 psi =450 Lit/hr
No. of Nozzle= Mass of water inlet
Nozzle Capacity
= 2100
450
= 3.89 = 4 nos
Nozzle Angle = 40°
Spray Distance :- 228 mm
Theoretical Coverage :- 175 mm
38. REFERENCES
➔ Spray Engineering handbook, CTG SH O7 HU,Pnr
➔ Fluid Mechanics and Hydraulic Machines, RK Rajput
➔ Desuperheater for waste heat, International Journal of Refrigeration, January 1983
➔ Kevin G. Schoonover, W.M. Ren, S.M. Ghiaasiaan, S.I. Abdel-Khalik, Mechanistic modeling of desuperheater performance, ELSEVIER, ISA Transactions 35
(1996) 45-51, May 1996.
➔ Kristin Donahue, Graham Corporation,Engineering Practice, Academia
➔ Peter Borzsony, Sanjay V. Sherikar, Advances in Desuperheating Technology for combine performance of CCPP, ResearchGate publications, PWR2005-50108,
January 2005.
➔ Marian Formanek, Jiri Hirs, Josef Diblík, Petr Horak, Experimental Increase in the Efficiency of a Cooling Circuit Using a Desuperheater, ResearchGate
publications,PPci.8399, 24 February 2016,
➔ ASME II SECTION D 2019.
➔ Indian Boiler Regulation (IBR) 2017 Alank Publication.
