Analysis on reducing power consumption of power plant

Plant power consumption is mainly consumed on 6kV auxiliary engines of boilers and turbine systems that are frequently running continuously. The equipment power consumption of the three auxiliary systems of wind smoke, milling, and circulating water accounts for about 70% to 75% of the total power consumption of the entire plant. Therefore, to dig deeper the potential for saving electricity from high-voltage auxiliary machines and reduce the power consumption of auxiliary equipment in the three major systems of wind smoke, milling, and circulating water is the key to reducing the electricity rate of the unit.

1 Potential Analysis of Auxiliary Power-Saving Power Savings 1.1 Potential Analysis of Pulverized-Cleaning System and Wind-Cleaning System 1.1.1 When the air leakage rate of air preheater is large, the loss of air leakage causes the increase of power consumption of the fan, and at the same time, if the air precipitator becomes dirty , It will cause some of the heat storage sheet corrosion, resulting in the unit pressure at the full load of the air pre-equipment high pressure difference, resulting in increased power consumption of the fan. In this regard, during the operation of the unit, it is necessary to ensure that the air pre-heater sealing device is operated automatically and reliably and that the soot-blowing requirements are strictly implemented. The #2B air preheater, #4, #5, and #6 fan-type panels cannot be put into operation for a long period of time because of transmissions, and the air leakage rate is about twice as large as that of the #2A. Therefore, it is necessary to eliminate this deficiency in time.

1.1.2 Reasonably arrange the operation mode of the coal mill combination. Under the condition that the AGC has not been put into operation, the unit will adopt the combination of three coal mills below the 350MW load. 350 ~ 500MW load, using 4 mills to run, above 500MW load, using 5 mills. For every 1 MPA reduction of grinding roller grinding force, the grinding current can be reduced by about 2A. Under the condition of ensuring the fineness of the qualified pulverized coal, the loading force can be appropriately reduced and the power consumption of the pulverizing system can be reduced. In addition, strengthening the overhaul process can reduce the failure rate of the coal mill and reduce the number of replacements of the coal mill.

1.2 Analysis of Power Saving Potential of Circulating Water System

Circulating pump operation mode. The Kemen Power Plant is a two-four-pump, liaison-and-velocity pump that communicates with the circulating jellyfish tube. On March 13th, a two-motor and three-pump approach was adopted to stop the 2B circulating pump, which was used for maintenance and treatment to leak water from the pump packing in the 2B cycle, saving about 3000kwh in one hour.

2 Power Saving Measures for Auxiliary Systems

(1) Reasonably adjust the operation mode of the vacuum pump and run it in normal operation.
(2) Reasonably adjust the operation mode of the fuel pump. One machine runs when the two machines operate.
(3) Minimize the operating time of the electric feed pump. Unless the work of terminating the steam pump is urgently needed, the steam pump replacement work should be handled during the low load period at night. At this time, the electric pump can not be started and the power consumption of the plant can be greatly reduced. .
(4) The overflow pump is adjusted to intermittent operation by continuous operation. When the overflow tank is at high water level, the overflow pump is turned on again.
(5) When the unit is under low load, the controlled oxygen content should not exceed 6.0% to avoid excess air coefficient being too large and further reducing the fan power consumption.
(6) The method of replenishing water in the chilled water tank is replaced by the condensate pump to make up the water by the demineralized water pump.
(7) Cancel trial run of open pump and water type vacuum pump during regular work.
(8) Reducing the amount of water pump recirculation and leakage. Close the condensate pump recirculation control valve above 500MW.
(9) Consider appropriately increasing the plant voltage within the allowable range.
(10) Elimination of running, running, dripping, and leaking, in particular, reducing steam leakage from steam turbines and improving turbine efficiency.
(11) Strict implementation of the lighting and ventilation management system at the production site.

During and after the outage of the unit, due to the low average load, even without load, the relative operation time of the auxiliary machine system will inevitably increase the power consumption rate of the unit plant. Therefore, the operation mode of the auxiliary machine system during the shutdown process is reasonably arranged. When the auxiliary machine reaches the outage condition, it will be shut down in time to minimize the operation time of the auxiliary machine, reasonably arrange the steps of starting the recovery system, and reasonably adopt the water supply method. When the upper water is used, the upper pump is used for water supply, and the auxiliary steam can be used for the large flow. Pumps, etc., using frequency control technology to carry out technical transformation of the pump load is also an effective measure to reduce the plant electricity rate.