POLYCITY. Technical measures and experiences at a 6 MW cogeneration plant with wood chip furnace POLYCITY

Transcription

1 Technical measures and experiences at a 6 MW cogeneration plant with wood chip furnace Content 1. Technical overview cogeneration plant and heating network 2. Investment of the facility 3. Experiences and measures to increase reliability 1

2 Overview powerplant Technical performance data Technical data biomass power plant Max thermal power wood combustion Electrical power ORC module Thermal power ORC module Capacity of wood storage Wood consumption full power Annual wood consumption Wood source Landscape conversation / forestation Heat production (final extension) Electrical power generation Fossil fuel savings Reduction CO 2 emissions Start of construction Start of run 8000 kw th 1000 kw el 5300 kw th 1400 m³ 200 m³/day m³/year 70% / 30% ~ 38mill. kwh/year ~ 5.4mill. kwh/year ~ 40mill. kwh/year ~ tons/year April 2003 June

3 Cost overview Net Investment in Euro Wood firing with thermo-oil heater ORC plant Building and incidental costs Total amount State subsidy approx approx approx Overview heat net Technical data district heat net Scharnhauser Park 2005 Piping Manufacurer of pipes Type of pipes diameters length volume Isoplus (Germany) Logstor (Denmark) Plastic jacking pipe singular isolated DN 25-DN ,5 km 280 m³ Performance data Pressure Number of transfer stations Yearly heating power Max. capacity Mass flow Volume flow Power net pumps Difference pressure Pressure level MWh/a 16 MW kg/s 43,5-460 m³/h 3 x 18,5 kw 0,7-1,1 bar 5-6 bar (feed) 4-5 bar (return) Temperature Feeding temperature Returning temperature C C 3

4 Critical devices 2 Heat transfer Ash output 3 1 Delivery devices Combustion chamber Thermo oil boiler Combustion designed to burn very wet material with up to 60% water content Dry material leads to high combustion temperatures, slagging problems and high exhaust temperatures Difficult to use the whole grate, necessary for generating power 4

5 Contribution devices Crane Programming and automation challenging Regular reset and manual mode necessary Relatively extensive maintenance Contribution devices Cross conveyor had no time limit Exclusively connected to rotating wing switch Caused bad pressings Solved by installation of ultrasonic level sensor 5

6 Contribution devices Cross conveyor had no time limit Exclusively connected to rotating wing switch Caused bad pressings Additional installation of ultrasonic level sensor Heat transfer Thermooil Economizer Pressurized air cleaning system Efficient for first rows of tubes, but too high turbulence for cleaning of deep hanging tubes 6

7 Heat transfer Water-Economizer Appearance of corrosion Probably caused by lack of cleaning and extreme part load conditions Heat transfer Water-Economizer Appearance of corrosion Probably caused by lack of cleaning Extreme part load conditions 7

8 Heat transfer Secondary air preheater Corrosion caused by suction of cold air from the bunker Heat transfer Secondary air preheater Corrosion caused by suction of cold air from the bunker Extension of cleaning devices to Water ECO and Air- Preheater Shut down of bunker suction 8

9 Pressurized air cleaning system Important to check metallic nozzles- exposed to exhaust fumes Cleaning heat transfer surfaces with dry ice system Very good cleaning effects compared to mechanical brush cleaning Effective even at thick caking No waste material like sandblasting technology 9

10 Important for an efficient revision: space Middlehall is used to place the upper shell of the thermooil boiler Important for an efficient revision: space Middlehall is used to place the upper shell of the thermooil boiler 10

11 Ash output Ash conveyor Not designed for high ash temperatures High density polyethylene Melting point 140 C Thank you for your attention 11