preHAZOP

Automated Safety Assesments in an early development Stage based on standardized DEXPI P&IDs ¹ and DWSIM process simulation exports ².

Authors:

Jonas Oeing, Tim Holtermann
TU Dortmund University, [Laboratory of Equipment Design](https://ad.bci.tu-dortmund.de/cms/en/laboratory/)

Install:

The preHAZOP application is available as python application.

Python installation:

1. Install Python (anaconda) from https://www.anaconda.com/products/individual
   

2. Load the following python libraries

   • NetworkX (vers. 2.6.3) ³
     
   • Matplotlib (vers. 3.4.3) ⁴
     
   • Pandas (vers. 1.3.4) ⁵
     
   • NLTK (vers. 3.6.5) ⁶
     
   • PySimpleGUI (vers. 4.60.0) ⁷
     
   • lxml (vers. 4.5.2) ⁸
     
   • openpyxl (vers. 3.0.9) ⁹
     

3. Open the folder preHAZOP_Application.

4. Running the script preHAZOP-ad@TUDO.py starts the preHAZOP tool.

Manual:

1. The preHAZOP tool consists of an Graphical User Interface for an easy application.
   

Figure 1. GUI of the preHAZOP tool.

2. Load the DEXPI-P&ID as well as the DWSIM simulation export into via the BROWSE buttons.
   
3. Push the button START. The preHAZOP is running until its finish by showing the message Run was successful! Results in Output.
   
4. The results (HAZOP-table) are stored into the folder ./Output. Additionally you find a file range_check_results.txt, which shows the results of an inconsistency check in design pressure and temperatures.
   

preHAZOP - Functionalitiy

Idea of the preHAZOP:

preHAZOP-scenario detection

The preHAZOP is able to detect the following HAZOP-scenarios automatically in an graph based P&ID (DEXPI). If necessary, the user can add more scenarios by extending the preHAZOP-database using the predefined drop-down menu.

Index	Description	Guideword	Parameter	Cause	Consequence	Safeguard_1	Safeguard_2	Affected Equipment	Propability	Requirements	Equipment_1	Specification_1.1	Specification_1.2	Equipment_2	Specification_2.1	Specification_2.2	Equipment_3	Specification_3.1	Specification_3.2
1	Pump effects vacuum cause of inert failure, resulting in vessel demolition	Lower	Pressure	Inert system failure	Damage	Pressure Low Shut down		Equipment_1	F1	Check min. operation pressure of vessel	Vessel	Inert		Pump
2	Pumping against wrongly closed valve results in damage of pump	Higher	Temperature	Valve wrongly closed	Damage	Bypass		Equipment_1	F1		Pump			Valves (operation)
3	Pumping against closed level control valve results in damage of pump	Higher	Temperature	Valve closed by control	Damage	Bypass		Equipment_2	F1		Column	Level Control		Pump			Valves (operation)	Level Control
4	Substance leaks out of pump cause of mechanical seal wear	Other	Flow	Mechanical seal wear	Seal leakage	Maintenance		Equipment_1	F1		Pump
5	Mechanical failure of the pump	No	Rotation	Mechanical failure	Damage	Maintenance	Redundant	Equipment_1	F1		Pump
6	Mechanical failure of the centrifuge	No	Rotation	Mechanical failure	Damage	Maintenance		Equipment_1	F1		Centrifuge
7	Stirrer damages vessel	Other	Rotation	Mechanical failure	Damage	Maintenance		Equipment_1	F2		Vessel	Agitator
8	Cooling circiut failure leads to a higher inlet temperature, resulting in a seal leakage of vessel	Higher	Temperature	Cooling circuit fails	Seal Leakage	Inlet Temperature High Alarm		Equipment_1	F1	Compare max. operation temperature of vessel with inlet temperature	Cooler			Vessel
9	Too much heating leads to a higher inlet temperature, resulting in a seal leakage of vessel	Higher	Temperature	Too much heating	Seal Leakage	Inlet Temperature High Alarm		Equipment_1	F1	Compare max. reachable temperature with max. operation temperature of vessel	Heater			Vessel
10	Pump is turned on when there is no medium in vessel, so it runs dry	No	Flow	Wrongly turned on	Damage	Level Low Alarm		Equipment_2	F1		Vessel			Pump
11	Pump is turned on when there is no medium in Column, so it runs dry	No	Flow	Wrongly turned on	Damage	Level Low Alarm		Equipment_2	F1		Column			Pump
12	Level Control failure leads to an empty vessel, so pump runs dry	No	Flow	Control failure	Damage	Level Low Alarm		Equipment_2	F1		Vessel	Level Control		Pump	Level Control
13	Level Control failure leads to an empty column, so pump runs dry	No	Flow	Control failure	Damage	Level Low Alarm		Equipment_2	F1		Column	Level Control		Pump	Level Control
14	Pump runs dry cause of a wrongly closed valve in front	No	Flow	Wrongly closed valve	Damage	Temperature High Shut down		Equipment_2	F1		Valves (operation)			Pump
15	An external fire effects a vessel rupture	Higher	Pressure	External fire	Rupture	Safety valve		Equipment_1	F3	Check content and max. operation pressure	Vessel

Consistency checks (pressure/temperature)

Examples

The folder ./preHAZOP_Application/Input containts example file for an distillation process of Ethanol/Water.

• Vizualization of the example DEXPI-P&ID¹⁰:

Figure 2. P&ID of a textbook distillation plant example.

• Vizualisation of the example simulation¹⁰:

Figure 3. Simulation of a textbook distillation plant example for ethanol/water.

References:

Footnotes

1. DEXPI Initiative, DEXPI Specification 1.3, https://dexpi.org/, accessed on 07-28-2022
   ↩

2. DWSIM process simulator, https://dwsim.org/, accessed on 07-28-2022
   ↩

3. NetworkX developers, online documentation, https://networkx.org/, accessed on 07-27-2022
   ↩

4. Matplotlib development team, online documentation, https://matplotlib.org/, accessed on 07-28-2022
   ↩

5. Pandas development team, online documentation, https://pandas.pydata.org/, accessed on 07-28-2022
   ↩

6. NLTK project, online documentation, https://www.nltk.org/, accessed on 07-28-2022
   ↩

7. PySimpleGUI, online documentation, https://pysimplegui.readthedocs.io/en/latest/, accessed on 07-28-2022
   ↩

8. lxml development team, online documentation, https://lxml.de/, accessed on 07-28-2022
   ↩

9. Charlie Clark, online documentation, https://openpyxl.readthedocs.io/en/stable/, accessed on 07-28-2022
   ↩

10. A. Behr, D. W. Agar et al., Einfuehrung in die Technische Chemie, Springer Spektrum, 2016
    ↩ ↩²