CSE-Engineering Center of Safety Excellence GmbH


The following projects show examples of the knowhow of CSE-Engineering. All projects were carried out by employees of CSE-Engineering within the last few years.

Industry projects – current research put into practice in the industry.

If you have any questions about our reference projects, please do not hesitate to contact us.


Explosion protection of a thermal afterburning plant.

Explosion protection concept | Gas explosion | Solvents

Thermal post-combustion plants are often used for the energy-efficient use of waste heat from chemical and petrochemical plants. Especially in plants with solvents, re-ignitions from thermal afterburning can occur if these are insufficiently protected.

Within the scope of the project, an explosion protection concept for the protection of the thermal post-combustion plant for the flow of gaseous hexane was developed using several possible protection methods. In addition to explosion decoupling, e.g. by flaps or sliders, this also includes explosion pressure relief with a Q-tube® or controlled burning with a flare.


Sizing of vent lines for multipurpose plants for the throughflow with vaporising gas/liquid mixtures.

Vent line – Emergency relief pipe – Two-phase flow

Multipurpose plants are often secured with mechanical safety devices like safety valves or bursting discs. Because of frequent product change, it is important to regularly examine if the safety device is large enough to allow the production of a new product in the existing reactor. However, the sizing of a safety device can be very complex on a case-by-case basis.

As part of a project the release surface depending on the reactor content and type of heating (external heat supply through a heat transfer medium, fire, chemical reaction) was calculated for about 60 typical solvents. Therefor the HNE-DS method was used in consideration of the boiling retardation of the liquid. Recommendations concerning how to handle product changes were developed for multipurpose plants with an existing safety device.

Literature: Schmidt, J. und Stoessel, F. (2011), safety and restraint systems for multipurpose plants. Part 1 – safety concepts and safety devices. Chemie Ingenieur Technik, 83: 1173–1187


Assessment of pressure shocks in a heat exchanger for the scenario of a ruptured pipe.

Heat exchanger | Pressure shock | Ruptured Pipe

In heat exchangers, leakages usually can’t be ruled out. They are expecially critical during the demolition of a pipe because the abrupt change of pressure can cause a pressure shock. This can deeply harm the heat exchanger.

Within the scope of a project the occurring pressure shock in a front head of a heat exchange was estimated. In the studied case, the low-pressure side was on the tube side. For this reason, the medium from the shell side is abruptly penetrates in the tube side. The resulting pressure wave spreads through the pipe until the end of the heat exchanger. Subsequently it spreads hemispherical until it reaches the wall. For this reason heat exchangers should be sized in a way that the pressure shock resistance of the vessel can’t be exceeded not even during the demolition of a pipe.


Protection of a heat exchanger for the scenario of a ruptured pipe.

Heat exchangers | Safety valve | Ruptured Pipe

he protection of a heat exchancer had to be conducted for the scenario of a ruptured pipe in this project. The operating pressure of the shell side which has to be secured is 30 bar. In case of a ruptured pipe within the heat exchanger the shell side has to be protected against the inadmissible high pressure of the tube side.

Under the assumption that the complete cross section of the pipe is released, the surface that the inadmissible pressure can pass into the shell area is two times the size of the free cross section of the pipe. The mass flux through this are represents the minimum of the mass flux that has to be dissipated through the safety valve. The flow through the valve occurs with a two-component flow out of the medium from the tube and shell side.


Simulation of the pressure and temperature profile in a 500 km long grid gas pipeline and evaluation of various pipe line routings.

Ecological efficiency analysis | Gas network | Grid gas pipeline

Various pipe line routings of a natural gas high-pressure pipe were assessed for the comparison of the temperature and pressure profiles for different load conditions (mass fluxes, summer/winter mode). Very precice equations of state were considered for different load conditions. The calculations were carried out for a 500 km long pipeline taking into account that natural gas is removed at several places of the pipeline for different consumers.

Places for compressors were optimised and a pipe line routing with a minimum of compressor stations was selected. These stations always require an interference with nature and are associated with high investment costs. With the use of the lowest possible number of compressor stations the CO2-emissions for the compression can be reduced.


Sizing of a safety valve for thwo-phase flow on a multipurpose reactor.

Safety valve | Emergency relief pipe | Two-phase flow

The the topic of this project was a multipurpose reactor that should be secured for the use of a certain substance. The maximum of the mass flux that needs to be dissipated has to be determined by a scenario definition. Based on this mass flux the proper safety valve can be determined.

The mass flux that can be dissipated through a safety valve for a two-phase emission can be determined with the HNE-CSE model. This model is a advancement of the approved HNE-DS model which is commonly used in the industry.

Literature: J. Schmidt, S. Claramunt: Sizing of rupture disks for two-phase gas/liquid flow according to HNE-CSE-model, Journal of Loss Prevention in the Process Industries, 41 (2016) S. 419 bis 432


Comparison of the approach for the protection of natural gas high-pressure pipelines in Germany and Switzerland.

Plant security | Grid gas pipeline | Dispersion calculation

In Germany risks have to be avoided in accordance to a deterministic safety approach. Appropriate safety-related measures have to be taken against risks that cannot be completely dismissed. In neighbouring countries like Switzerland, the Netherlands and Great Britain the evaluation of risks by a probabilistic approach is mandatory.

During this project the approaches for the protection of technical plants in Germany and Switzerland were compared in detail. The swiss framework report for natural gas high-pressure pipelines was used as a basis for the comparison. The influence of the pipe diameter and the permissible pressure of the pipeline on the possible effects during a worst case scenario were considered.

Literature: J. Schmidt: Safety of natural gas high-pressure pipelines in an international comparison using the example of Germany and Switzerland. IRO Oldenburger Rohrleitungsforum, Oldenburg, 7./8.


Sizing of a separator for the separation of liquids in the emergency relief of production lines.

Separator | collection container | simultaneous discharge

In a project, a separator was dimensioned for the separation of liquids from several reactors whose safety devices do not respond simultaneously. In order for the separator to function, the flow conditions at the inlet had to be tested and optimized for the various emergency relief scenarios. Reacts on the other safety devices in the event of an emergency relief had to be excluded.


Eco-efficiency analysis of a long-distance gas pipeline more than 1000 km long.

Eco-efficiency | Resource evaluation | Energy use

In the construction of a natural gas pipeline, considerable resources are sometimes used, e.g. for the steel and the sheathing of the pipeline. During subsequent operation, the compressors produce CO2 as exhaust gas in the environment. Depending on the pipeline layout, the overall project will have a more or less good balance for the eco-efficiency of the pipeline.

A consortium of experts evaluated the eco-efficiency analysis of a new building project. The distribution of compressor stations along the pipeline and the selection of pipeline diameters and operating pressures were the focus of CSE-Engineering’s investigations.


Measurements of condensate content, particle number and distribution in natural gas high-pressure pipelines.

Gas pipeline | Condensate content | Flow investigation

In Germany, natural gas pipeline networks are typically operated at pressures between 95 and 50 bar. The pipeline diameters are between 500 and 1400 mm. Gas drying plants are located at the gas feed stations of the pipeline network in which the moisture in the natural gas is reduced by absorption of water with diethylene or triethylene glycol (dew point reduction).

When the natural gas is dried, a very small amount of glycol is dissolved in the gas and flows into the pipeline. As a result of the subsequent drop in temperature and pressure in the pipes, the glycol condenses and precipitates on the pipe walls. The mass of glycol in the natural gas after drying was measured in a gas drying plant. Both the dissolved portion and the portion of glycol entrained in the form of particles (aerosols) were determined. For the measurements, an appropriate test rig for the isokinetic extraction of natural gas and for the measurement of particle size distribution using a xenon transmitted light measurement method was developed. The mode of operation of the pipeline (summer/winter operation) and the effects of a recondensation of already existing glycols were considered during the modelling of the condensation.

Literatur: D. Jerinić, J. Schmidt, M. Piontek: Calculation of the condensation of low-volatility components in gas pipelines. GWF Gas Erdgas 01/2009