Expansionsmaskiner istället för strypventiler - en effektivisering

Sammanfattning: In Uppsala CHP Plant, there are six pressure reducing valves to reduce the pressure from 15 to 3 bars, before six absorption heat pumps. During the process the energy is conserved but losses occur in form of exergy. The aim of this thesis is to reduce the losses of exergy. This can be done by letting turbines replace the pressure reducing valves. In this thesis an investigation has been done of the conditions today, the conditions after the change from pressure reducing valves to turbines and a comparison of three different types of turbine solutions. The three examined solutions are one turbine, several helical screw expanders and several small turbines in parallel with asynchronous generators. The six absorption heat pumps have been divided into two groups; one group of four and one group of two absorption heat pumps. An investigation of locations and space in nearby switchgears has been done for each group. Contacts with retailers of the examined turbine solutions have been taken to gather technical specifications. These technical specifications have been used to simulate the electricity production and the economical yield of each type of examined solution. The investigation shows that the best solution is the solution with several small turbines with asynchronous generators. It has lower investment cost (15 [MSEK]) and the best yield. The proposed solutions will have an installed capacity of 2.65 [MW] to a cost of 5 601 [SEK/kW]. The electric energy production will be 15.7 [GWh/year]. An investment is recommended to a future electric energy price around 400 [SEK/MWh]. Before an investment it is recommended to investigate how to optimize the regulation of the new system with absorptions heat pumps and turbines.