A steam utility network model for the evaluation of heat integration retrofits – A case study of an oil refinery
Paper in proceeding, 2016

This paper presents a real industrial example in which the steam utility network of a refinery is modelled in order to evaluate potential heat integration retrofits proposed for the site. Total site heat integration techniques have previously been used for the refinery to identify a number of possibilities for heat saving retrofits. However, the profitability and actual primary energy saving will depend on the configuration and operation of the utility system. The supply of utilities such as fuel, steam and electric power represents a significant operating cost for many process industries. A reduced use of utilities can improve process economics and reduce the environmental footprint of the process. Heat integration, within and between the refinery process units, is one way to improve the energy efficiency and reduce the use of steam and fuels. Such heat integration measures will affect steam consumption and generation at different steam pressure levels within the network. A refinery, typically, has flexibility in their operation of the steam network from a number of switchable steam turbine-driven or motor-driven pumps and compressors. Furthermore, due to seasonal variations the amount of internally generated refinery fuel gas will vary, leading to periods of steam over-production as well as periods with a demand for additional purchased fuel. Consequently, the optimum operating strategy concerning steam production and the switchable mechanical drives is a trade-off between the cost of fuel and electricity. * Corresponding author 0258-1 2 This paper presents a few examples of heat integration retrofit measures from a case study of a large oil refinery. In order to evaluate expected changes in fuel and electricity imports to the refinery after implementation of the proposed retrofits, a steam system model has been developed using commercial software. The model enables an analysis of how the operation of boilers and turbines could be changed in effect of a proposed change. The steam system model has been tested and validated with real steady state data from three different operating scenarios. It can be used for simulation or optimization to answer how changes to steam balances at different pressure levels will affect the overall steam balances, generation of shaft power in turbines and electricity demand for pumps and compressors, and the consumption of fuel gas.

Pinch analysis

Energy cost savings

Oil refinery

Modelling

Steam network

Heat integration

Author

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Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

[Person 57a757c4-70ae-46fe-aa56-047653ea8b2a not found]

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

[Person b2a25093-a2f9-4c32-8cf3-1a27cedbab05 not found]

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

[Person 7ff72536-d48c-43b9-a6e5-0f3ca686ad39 not found]

Chalmers, Signals and Systems, Systems and control

[Person 218ebd02-f8e3-404e-a9ca-ae0f0529156e not found]

Chalmers, Energy and Environment, Industrial Energy Systems and Technologies

Proceedings of the 2nd South East European Conference on Sustainable Development of Energy, Water and Environment Systems, SDEWES.SEE2016.0258

2nd SEE SDEWES conference
Piran, Slovenia,

Subject Categories

Energy Engineering

Other Chemical Engineering

Areas of Advance

Energy

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1/17/2022