Jianghua Yao Autonomous County is under the jurisdiction of Yongzhou City, Hunan Province. It is the only ethnic minority autonomous county in Yongzhou City Hunan Province and the only Yao Autonomous County in Hunan Province. Among the 13 Yao autonomous counties in the country, Jianghua Yao Autonomous County is the county which has the most population, and is known as the “Capital of Yao Nationality in China". There are many small and medium sized chemical plants in this county. Originally these chemical plants built small hydro power stations themselves and the electric power generated by those small hydro power stations was used by these chemical plants. In these cases, the power factor was not taken into consideration. As the state began to advocate the idea of energy saving and consumption reduction, these small and medium sized hydro power systems were banned, so all these small and medium sized chemical plants had to use the municipal electricity. As a result, many of these chemical plants have faced with the electricity adjustment charges.
Mashi Chemical Plant is one typical representative of these small and medium sized chemical plants. This cmpany had to pay nearly 20,000 yuan a month as the electricity adjustment charge, which had been deeply perplexing the management of the company!
Statistical table of electricity adjustment charges
|
Month
|
Power factor
|
Electricity adjustment charge
|
|
10
|
0.841
|
16800
|
|
11
|
0.798
|
21000
|
The electricity adjustment charge, which is almost 100000 yuan a year, had added to the burden of this enterprise. This had become an issue of depression in the heart of the company management. Something had to be done to improve the situation! Through searching the item “Electrolyzer reactive power compensation management” on the Internet, this company had found out and contacted Anhui DELITER Electric Power Science and Technology Co., Ltd. After many communications and contacts had been carried out, Anhui DELITER Electric Power Science and Technology Co., Ltd sent its professional and technical personnel to perform the inspections on the site!
On the basis of the investigations which were carried out on the site, it was known that Mashi Chemical Plant mainly engaged in production of potassium hypochlorite, the main raw material of the chemical fertilizer. The load equipment were two electrolyzers and the rated powers of these two equipment were 950kw and 1050kw, respectively. The load power was stable and there were not any abrupt changes in the current. A harmonic test was carried out and the test results show that there were 5 order harmonics and 7 order harmonics in the system (which did not exceed the specified values). After an analysis and researches were performed by the technical personnel on the site, it was finally decided to adopt the design of mounting one reactive power compensation capacitor cabinet on the 10kv side for the customer. This has solved the problem related to the power factor!
Considering that there were harmonics on the site and the load was 3 sets of equipment, the technician of Anhui DELITER Electric Power Science & Technology Co., Ltd made the design to adopt one 10kv reactive power compensation capacitor cabinet with a total capacity of 2500 kvar. This equipment is able to perform automatic group switching on and switching off; this equipment is connected in series with one 6% reactor for the purpose of suppressing the harmonics in the system! Later after the installation and debugging on the site were completed, the obtained compensation effect was more than 0.92. This has won the recognition of the management of Mashi Chemical Plant and solved the problem of electricity adjustment charge for this enterprise!
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