How can we do a good job in current energy conservation and emission reduction efforts? Especially, what are the water-saving measures for circulating water systems?

Water conservation in circulating water systems relies primarily on proper management of the concentration ratio, as well as careful control of chemicals used, in order to avoid any negative impacts on the equipment resulting from reduced discharge. As for the discharged water, if reuse is considered, water treatment equipment such as membrane treatment is required. On the other hand, pipeline management should be strengthened to prevent leaks in the circulating water pipelines and unauthorized discharge.

Generally, our rotating equipment is cooled using circulating cooling water, and such equipment usually operates in a one-in-one-backup configuration. After switching over, many organizations fail to stop using the cooling water for the backup unit, resulting in waste!

At present, some of the good practices in our company are as follows: 1\ Reusing water that has been treated for wastewater disposal (of course, the initial investment for this is relatively high, but the energy-saving effects are good). 2\ Increasing the concentration ratio; the extent to which this should be increased needs to be determined through practical testing. 3\ Managing the temperature difference of water in devices that use recycled water – for example, we require that the temperature difference between the inlet and outlet water in all such devices be at least 5 degrees. I hope these methods will be useful to you: lol

Based on the current operations of our company and the water-saving measures in place, I would like to share my experience: 1. Ensure the quality of the raw water used for replenishment, and appropriately increase the concentration ratio of the recycled water (as long as it remains within the limits permitted by the quality standards for recycled water). 2. Strengthen the daily management of the recycled water system to keep its quality within an appropriate range. Our company assigns dedicated personnel to oversee this process, with regular water quality tests being conducted; chemicals are added as needed to treat the water and ensure it meets the required standards for operation. 3. Quality control and management of the scale inhibitors, disinfectants, and other chemicals used. 4. Improved management and operation of all users of the circulating water in the plant, in order to minimize any impact on water quality; attention must also be paid to the operation of filters, as this is crucial during normal operations, especially during cleaning (or regeneration) processes. 5. Enhanced operation of the cooling towers, ensuring that the water entering them is properly cooled, thus maintaining the appropriate temperature of the feed water.

Due to cost considerations, our company separates the clean water from the wastewater in the recirculated water stream, that is, it reuses the clean water after it has been used. I am currently conducting experiments on wastewater treatment (mainly to reduce costs) with the aim of recycling it.

The circulating water wastewater can be directly returned to the water used for production, without any special treatment required.

The make-up water used in the circulating water system of our facility is reclaimed water that has been treated at local wastewater treatment plants to meet specified standards (**Grade 1 discharge standards**). This approach not only reduces the consumption of fresh water but also lowers water costs； Since fresh water is not only expensive but also includes discharge fees, using reclaimed water to replenish the circulating water (of course, under appropriate conditions) can definitely reduce costs; generally, the cost per ton of reclaimed water is lower than that of fresh water (tap water).

Reusing reclaimed water can not only reduce the consumption of fresh water but also increase the concentration factor when done properly.

Who can explain in detail how to write materials on this topic?

Reply to 1# zhaoweidong: There is one very crucial point – we are often constrained by the requirements of the problem itself. Where energy is concentrated, and given the availability of funds, it might be possible to use a non-circulating water system to address the issue, such as through the recovery of thermal energy, thereby creating a self-balancing system for process energy. Of course, investment will also increase, such as by introducing heat pump systems ； Furthermore, for existing circulation systems, enhancing heat transfer, reducing scaling, and cleaning the surfaces can serve as physical methods ； For process systems as well, achieving full energy self-balancing is the ultimate way to reduce the consumption of circulating water.