Analyzing And Operation Optimization For Industrial Steam Heating Networks

Recently, constructing industrial parks has become a main way to develop modern industry, and in industrial parks, there are concentrated project of electricity, gas, water and heat-supply. As the steam affects the manufacturing process and the production security of heating consumers, the heating pipe system needs to be more secure and reliable.At present, industrial steam heating networks are usually ring-shaped with multiple heating sources, and the drainage of steam traps maybe3%-10%of the total heat supply of heating networks; meanwhile, the working conditions would be changeable due to the high frequency and wide range of load variation of heating consumers. Under a specific working condition, it may lead to the steam disqualification of far-end consumers, or even a long time low steam velocity (namely "steam stagnant") in certain pipes, which may result in condensation-induced water hammer (CIWH) that will threaten the security of the whole DH system. They all display the importance of analyzing and operation optimization for industrial heating networks.To realize the analyzing and operation optimization for industrial steam heating networks, following studies are presented in this paper:(1) A drainage calculation method of steam traps based on heat dissipation of pipes is presented, and a hydraulic calculation model considering heat dissipation in pipes based on "directed graph model" is built, with the theories above, steam flow regime in pipes can be calculated and the precision is higher than traditional hydraulic calculation method.(2) Specific to ring-shaped heating networks with multi heating sources, a method of eliminating steam stagnant through optimizing the heat load of each heating source is presented to prevent CIWH.(3) Based on the theories aforementioned, a general analyzing and operation optimization software system for industrial steam heating networks which can connect to the real-time database is presented in this paper, it can realize online hydraulic calculation and operation optimization for arbitrary structured heating networks, and help operators to manage heating networks through providing them the theoretical temperature, pressure of heating consumers and pipes, etc. And low-flow data which can’t be measured can be calculated with the software system presented in this paper, so steam stagnant can be examined and CIWH can be prevented with the operation optimization method presented in this paper.At present, the practical application of the software system in a large-scale chemical industry zone shows its stability and rapidity to realize online hydraulic calculation for steam heating networks, and the error between measured data and calculation data is below5%, immeasurable data can be calculated with the software system presented in this paper, and the method to prevent CIWH is proved effective to improve the safety of steam heating networks.