Based on the concept of industrial symbiosis, which describes the combination of physically or virtually connected businesses within a certain area in a mutually beneficial way, the concept of Eco Industrial Park (EIP) has been brought forward to achieve maximum productivity with minimum cost of resources. Indeed, an EIP could be among the most energy-intensive areas of a country, correspondingly waste heat will also account for a considerable proportion. For instance, it is reported that the Yeosu National Industrial Complex in South Korea consumes 15% of the total energy of the country, while producing 47% of the total industrial waste heat. In EIP the geographical proximity between different users offers new possibilities for WHR; in fact, some waste heat that does not have end-user in one plant may be used in another, therefore WHR network can be formulated. In such cases, the plant supplying heat is defined as source plant, whereas the plant receiving heat is defined as sink plant. Besides, if the waste heat from source plants can be used by neighboring communities, the overall energy efficiency of EIP can be further improved through urban-industrial symbiosis. The optimization of WHR network at EIP level (inter-plant) is quite different from the optimization of WHR at single plant level (intra-plant). Currently the popular method used for WHR optimization in EIP is linear/nonlinear programming based on objective functions and constrains. The current research activity still presents room to improve in the following areas:
- The multiple criteria decision-making. Various objective functions, including energy efficiency of the EIP, payback period of the WHR network, CO2 emission reduction etc. have been proposed in the literature, as a result different WHR network scenarios can be selected. Yet the attempt to satisfy multiple and possibly conflicting objectives simultaneously is seldom discussed.
- The analysis of waste heat transportation system. The temperature drop and energy loss during waste heat transportation has been mentioned in some papers, yet the configuration of the waste heat transportation system has not been discussed in detail.
- The influence of intermittent waste heat on the optimization process. Almost all existing studies assume constant waste heat profile, but this may not be the case for some batch processes. For such processes, the waste heat profile could vary over time, thus influencing the performance of the WHR network; therefore, the intermittency of waste heat also merits to be investigated.
Useful Links
J-Park Simulator, A Part of The World Avatar Project
Cambridge Centre for Advanced Research and Education in Singapore (CARES)
Computational Modelling Group, University of Cambridge
Thermal Energy Systems Lab, Nanyang Technological University