Abstract
The shortage of energy and water is a critical issue in various industrial sectors especially in chemical engineering industry. Using the system integrated method can greatly reduce the fresh water and public utility consumption. The integration of water network and heat exchange network can merely optimize the usage of water and energy respectively, but the optimization of heat-integrated water networks can reduce not only the water consumption but also the energy and heat exchangers. This paper introduced the regeneration of wastewater into a single contaminant heat-integrated water networks, and improved the temperature- concentration graphical method. The optimization here presented the design method for heat-integrated water networks considering the regeneration recycling of wastewater and the regeneration reuse of wastewater. Compared to the earlier method, this method reduces the consumption of fresh water from 90 kg/s to 20 kg/s, and it also reduce the minimum heating utility consumption from 4,165 kW to 1,929 kW. The improved temperature-concentration graphical method of wastewater regeneration recycling system is better than that of wastewater regeneration reuse system. Considering the regeneration of the wastewater to optimize the heat- integrated water network, the consumption of fresh water and minimum heating utility decreases greatly and the result of water-saving and energy-saving is obvious.
