Regarding power saving issues

Saving power should mean doing as little work as possible while still meeting the process requirements. 1. Choose a motor of appropriate size (without excessive excess capacity); avoid using a motor that is too powerful for the task. 2. If the parameters change significantly, an inverter can be installed. 3. Select high-efficiency pumps or improve their efficiency by modifying them. 4. Examine the process: pumps that can be stopped should be turned off when possible, and they can operate intermittently

Applying variable frequency control to the equipment is a good approach

How much does adding variable frequency drive increase the cost of a pump? Not every pump is equipped with variable frequency drives – apart from cost, what other factors are involved?

Examples of power savings in coking units for reference: optimizing the operating time of electrical equipment to reduce the unit’s power consumption. ① Actively carry out efforts to improve coke removal processes. By increasing the frequency of the reaming and coking removal operations in order to reduce the time required for coking removal, and through adjustments and optimization of these processes, the coking removal time has been reduced from 3.6 hours at the beginning of the year to 2.8 hours currently, resulting in a power savings of approximately 91,200 kWh per month ； Affected by the shortened defocusing time, the operation time of the train during the defocusing process is reduced by approximately 40–45 minutes per cycle, resulting in a power savings of around 19,600 kWh per month ； ②Increase the frequency of use of high-efficiency pumps. While strengthening the management of variable-frequency equipment, the workshop has expanded its approach: for pumps that currently do not have variable-frequency drives, efficiency tests are conducted on the AB pumps within those systems to identify those with high efficiency. Corresponding operating procedures are developed and distributed to the work teams for study. Wherever possible, high-efficiency pumps should be used within the limits permitted by the production conditions. Pumps within the system that experience significant load fluctuations are identified and analyzed, with variable-frequency drives to be installed at an appropriate time ； ③Shut down the dry gas desulfurization lean liquid pump. By introducing the advanced energy-saving concept of \"eliminating intermediate tanks,\" three-step optimization tests were carried out on the dry gas desulfurization unit to achieve direct supply of lean liquid, ultimately resulting in the shutdown of the lean liquid booster pump P1301 (55 kW). Following optimization tests, the lean liquid pressure boost pump P1301 was successfully shut down on August 31; the plant continued to operate normally and the product quality remained satisfactory. After the lean liquid booster pump P1301 is shut down, 65 kWh of electricity can be saved per hour; this results in an annual savings of 585,000 kWh, as well as a reduction in installation costs of 339,300 yuan ； After shutting down the lean liquid buffer tank, the consumption of fresh water for buffer tank protection can be reduced to 0.3 t/h, and the nitrogen consumption can be reduced to 50 Nm3/h ； Stopping the lean liquid booster pump can reduce maintenance costs by 10,000 yuan per year ； ④Innovatively carry out bubble coking operations in coke towers. Organize employees to study carefully the \"Technical Plan for Coking Tower Foaming Test in Delayed Coking Units\" and carry out foaming operations. Two petroleum coke bubble coking tests were conducted successively from September 7 to 10. After implementing the coking tower bubbling operation, the top temperature of the coking tower dropped to 108°C, and the top pressure was between 0.004 and 0.006 MPa, meeting the process requirements. Currently, the workshop continues to carry out this bubbling operation throughout the 24-hour coking cycle, with good results. After implementing the coking in the coke tower operation, 1010 kW•h of electricity can be saved per coking cycle, and 500 tons of circulating water can be conserved.

Our boiler feed pump is equipped with a 10,000-volt motor. Due to leaks in the pump’s auxiliary lines, it was necessary to operate two pumps in order to maintain production; now that those auxiliary lines have been sealed off, one pump is sufficient to keep production running.

In addition to carrying out some technical upgrades, as mentioned above, our company takes the following measures: 1. Choose motors of appropriate size (without excessive margin); avoid using motors that are too powerful for the task. 2. If there are significant variations in parameters, an inverter can be installed. 3. Select high-efficiency pumps or improve their efficiency through modifications. 4. Examine the process – pumps that can be stopped should be turned off when not in use, and operation can be intermittent, etc. In fact, saving electricity helps companies cut costs; electricity prices vary from hour to hour in different regions. For example, by scheduling the coking process for the evening, when electricity prices are lowest, it is possible to save a significant amount on production costs.

The largest electricity consumer in catalysis is the unit; efforts should be made to recover the energy from flue gas in order to reduce power consumption. For the fractionation stabilization system, the reflux in each section should be optimized, and unnecessary pumps should be shut down, such as certain air-cooled fans in winter and the oil-sealing pumps used with lean absorption oil. Additionally, the lighting of the facility also needs to be controlled, with the timing for turning on and off the tower lights adjusted according to different seasons, etc

Variable-frequency pumps are good, but their cost is too high, and maintenance is also an issue.

In fact, one hour can be set aside at night for inspections during power outages; this helps to save on electricity costs, and it also allows certain issues to be detected during inspections in the dark! Kill two birds with one stone!

Keep the catalytic flue damper as wide open as possible, as this can reduce the current consumption of the main fan, thus saving a significant amount of electricity.