Objectif
In Kreuzberg operates a district heating net with a connected load of approx. l00 MW. The thermal energy required for the customers supply is taken, via heat exchanger, from an adjoining district heating net. Heat is made available by oil-fired peak load boilers. The generation plants are situated in residential area.
The aim is to optimise the operation of the district heating net by means of a process control system .
The peak load boilers can then be used as rarely as possible. Capacities will be made available by the process control system for the connection of both partially and entirely supplied customers to the district heating system without increasing the producer capacities.
The thermal energy is mainly generated by low pollution and efficient cogeneration plants. In addition to a higher thermal output, the optimised district heating net is in a position to receive more thermal energy from the district heating net. Also, the peak load in the district heating is cut down.
Because of the large software-development concerning DDC-control algorithms optimised controller reactions could be achieved in the substations as well as in the power stations. The early morning peak level of consumption of the district heating network could be decreased by nightly increasing the pre-run network temperature.
The control response of the substations was improved by the use of the central control input (outside temperature).
It is intended to prepare and to evaluate in the future series of measurements in order to accomplish further optimisation. Correspondingly more results will be provided later.
At the beginning of 1985 the idea was developed to equip the existing district heating net of EAB Fernwaerme GmbH with comprehensive measurement techniques in order to ensure an optimal utilisation of the net after having collected and evaluated the relevant data. When the project was started, approx. 80% of the house stations were equipped with inflexible analogue control systems and 20% with a programmable DDC control. However, any optimisation can only be carried out with a programmable control.
For this purpose, 100% of the large house stations as well as all generation components had to be sized with regard to remote control techniques and to be figured in the computer as process illustration. All recently established and the larger existing house stations as well as all generation components have been equipped with DDC control in order to ensure a comprehensive hardware-oriented measuring.
Due to this procedure it was possible to determine different factors such as: * heat losses in the district heating net,
* heating and cooling behaviour of the consumers during switching between day and night operation, * heat demand of consumers as function of the outdoor temperature and possibly the insulation for day and night operation,
* efficiencies of the EAB plants as a function of the performance and of the outdoor temperature. The registered data are adapted by an overriding process control system.
In the framework of an ensuing network analysis, the different generation components, distribution configurations including their heat capacities and consumers, consumer groups and their behaviour have been investigated and evaluated.
Optimisation strategies as well as a mathematical model of the net will be acquired on the basis of the results of the network analysis.
In a further step the strategies are integrated into the system.
The process control system is then in a position to:
* monitor the regular operation,
* control the heat generation plants,
* avoid peak demands and subsequently to reduce the utilisation of the peak load installations and * control the hydraulics of the net.
Because of this procedure several opportunities are given to operate the EAB-FW net in the most optimal way. Especially with respect to the reduction of the primary energy consumption in dependence on the most influencing variables such as:
* meteorological conditions,
* availability of heat sources,
* oil price,
* environmental load,
* heat capacity of net and consumers.
The data recorded in the central computer of the process control system and the experience gained during operation can be used for the design of new plants, for the determination of optimal repair and maintenance strategies and for the flexible adaptation of the operation strategies. This data can also be used in operation management which is subject to considerable variations in each case of application.
Thème(s)
Appel à propositions
Data not availableRégime de financement
DEM - Demonstration contractsCoordinateur
10785 Berlin
Allemagne