Master thesis - Detecting leaking valves

Every day you breathe in over 20000 liters of air and spend an average of 90% of your time indoors. Indoor ventilation solutions affect everyone whether you see our products or not. FlktGroup is a market leader in innovative and energyefficient indoor climate solutions which ensure comfort safety and performance while reducing the carbon footprint. We have been setting the technical standard for over 100 years and with our broad product portfolio we can meet the most comprehensive customer requirements. FlktGroup is owned by Triton and has its headquarters in Germany. We have approximately 4000 employees worldwide with production facilities in Europe Asia and the United States.
Together We Create Excellence. For Life. Read more about us

About our function
At R&D we work to drive the development of our products in ventilation. In Jnkping we are responsible for the development of air handling units and chilled beams which means that expertise product development and a large part of the manufacturing of the products take place here. Our function consists of teams in mechanical design control and regulation laboratory and technology development and we have among other things one of Europes largest and most advanced laboratories.

General background

In an AHU the heat recovery system is the first in line of components that are used to heat the incoming outdoor air but if the recovered heat is not enough additional external heating is needed. External heating is sometimes provided from a hydronic heating system via an air coil in which heat is transferred from the liquid to the incoming air stream. The liquid side of the air coil is made up of copper tubes while the air side is made up of aluminum fins whereof the area of the fins in total is much larger than the total area of the copper tubes due to the limited heat capacity of air in relation to liquid.

As the available capacity in the hydronic heating system typically is much larger than the capacity that is required to heat the air stream the amount of heat that is transferred in the air coil must be limited. At the same time the required heating capacity varies depending on outdoor air temperature amount of recovered heat user demand etc. which means that the transferred heat continuously needs to be adjusted to the current conditions. This is typically done with the means of control valves that either adjust the inlet temperature at the liquid side of the coil by mixing the coil outlet stream with the coil inlet stream or by adjusting the flow rate of liquid through the coil.

Project background

As indicated in the background if the demand for external heat in the AHU is zero the valve should close and no heat should then be transferred from the hydronic system to the air stream. However a common error of valves is leakage which can occur anytime during its lifetime and the reason could be both mechanical or electronical. Typical mechanical errors can be plunger blockage caused by small particles buildup of limestone or magnetite in the valve seat damage on sealings or plunger due to cavitation etc. broken shafts or misalignment between seat and plunger. Typical electronical errors could be damaged actuator (to gears or electronics) wrongly installed actuator resulting in that the end position does not match the closed position of the valve power failures force deficits etc.

Nevertheless any of the errors above will cause the valve to leak which means that energy will be used even though there is no demand. Since an AHU typically is equipped with both heater and cooler any leaking valves will be automatically compensated by an increased operation of the other unit which means that the energy waste will double without any easy ways to identification.

Project description

The project aims to develop and evaluate different technological features to detect leaking valves in the application of heating and cooling in AHUs. Several ideas have already been proposed from FlktGroup and part of the work includes summarizing structure and describing and further to test and validate the concepts in our laboratory.An appropriate background of the project members is in mechanical energy or mechatronics on a masters degree level.

Time plan

The project will start after agreement between the students and us.

Our promise

It is simple for us. To be the leaders in air technology our technical development and our dedicated employees are central. FlktGroup Sweden AB has about 750 employees and we have production and development in Jnkping and Jrna and 16 sales offices in different locations across Sweden. We offer exciting challenges in an international environment. Specialists and generalists work here in areas such as sales development production IT logistics marketing and finance. At FlktGroup the cooperation between our knowledgeable employees in several professional areas is a strength. Our culture is characterized by teamwork and entrepreneurship where our everyday life is about an ambitious and flexible attitude. We help each other to find the best solution no matter what challenges we encounter. Both in our work and for our customers.
Together We Create Excellence. For life.

Additional information

This bachelor thesis must be written in English.In your application you send in your CV and a motivation to why you would like to do this project in collaboration with us.

If you have any questions you are welcome to contact Mattias Gruber Global Technology Director at

Last application date is the 24th of November.