12,556 research outputs found
On green routing and scheduling problem
The vehicle routing and scheduling problem has been studied with much
interest within the last four decades. In this paper, some of the existing
literature dealing with routing and scheduling problems with environmental
issues is reviewed, and a description is provided of the problems that have
been investigated and how they are treated using combinatorial optimization
tools
The economic and environmental performance of distribution networks: A case study from the petrochemical industry
Designing a company's distribution network is a challenging task that requires the consideration of different aspects. In this respect, especially trade-offs between, for example, operational costs and customer service are the focus of the companies' attention. However,
growing concerns of governments and customers about environmental protection have raised awareness towards the environmental impact of operations. Activities associated with the distribution of products, i.e. transportation and warehousing, are not yet subject to strict
environmental regulations, but this situation is expected to change soon. Companies must, therefore, start to concentrate not only on economic but also on environmental aspects in the design of their supply chain. Based on a case study from the petrochemical industry, this paper presents a way to combine both, economic as well as environmental criteria, when evaluating (strategic) distribution network design decisions. The results show a trade-off between total (distribution) costs and transport carbon emissions. (author's abstract
A novel bidding method for combined heat and power units in district heating systems
We propose a bidding method for the participation of combined heat and power
(CHP) units in the day-ahead electricity market. More specifically, we consider
a district heating system where heat can be produced by CHP units or heat-only
units, e.g., gas or wood chip boilers. We use a mixed-integer linear program to
determine the optimal operation of the portfolio of production units and
storages on a daily basis. Based on the optimal production of subsets of units,
we can derive the bidding prices and amounts of electricity offered by the CHP
units for the day-ahead market. The novelty about our approach is that the
prices are derived by iteratively replacing the production of heat-only units
through CHP production. This results in an algorithm with a robust bidding
strategy that does not increase the system costs even if the bids are not won.
We analyze our method on a small realistic test case to illustrate our method
and compare it with other bidding strategies from literature, which consider
CHP units individually. The analysis shows that considering a portfolio of
units in a district heating system and determining bids based on replacement of
heat production of other units leads to better results
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