Minyuan Steel Group was founded in 2003. It is located in the iron and steel casting professional park of Yongcheng economic and Technological Development Zone in Henan Province, which has a total area of more than 2600 mu, with more than 3000 employees. It integrates modern advanced technical equipment such as sintering, ironmaking, steel-making, rolling and supporting energy-saving and environmental protection facilities. It mainly produces high-quality screw steel, high-speed wire rod and screw products of various specifications, with an annual production capacity of 3 million tons. It is one of the leading private iron and steel enterprises in Henan Province and the production base of high quality building materials in the east of Henan Province.
The KDON(Ar)-11000/20000/300 air separation plant provided by DEAR air separation adopted energy saving design, which lead to a 1000KW decrease of the motor power of air compressor compared to other plants of the same scale.
It was successfully started and put into production. After one and a half year's operation, the equipment is stable, and each index is higher or better than the contract value. The discharge pressure of air compressor is reduced from 0.52MpaG to 0.412MpaG.
1. Performance parameters
According to the site conditions specified by the user, the air separation unit produces several products at the same time, reaching the following quantity and quality:
The product summary is as follows:
Design condition
|
Name of product |
Output Nm3/h |
Purity |
Out Bound Pressure MPa(A)
|
Out Bound Temperature ℃ |
|
Oxygen
|
11000 |
≥99.6％O2 |
0.12 |
15 |
|
LOX |
200 |
≥99.6％O2 |
0.12 |
Saturated |
|
Nitrogen |
20000 |
≤10PPm O2 |
1.1 |
42 |
|
LAr |
300 |
≤2ppmO2 ≤3ppmN2 |
0.115 |
Saturated |
The unit of measurement Nm³ / h is measured at 0 ℃, 0.1013mpa (a). It is called standard state flow
Extraction of liquid oxygen and liquid argon at different times
2. Operational flexibility
The plant can operate in the range of 75% - 105% of the designed oxygen output under variable load condition without any additional equipment (under the design condition), and meet the requirements of maximum and minimum product quantity.
3. Operational characteristics
（1）Operation cycle and device life
（2）The continuous operation period of the device is 2 years, except for simple maintenance.
（3）Design life of the device ≥ 20 years.
（4）According to the guidance of DEAR, the main equipment can meet the requirements of this contract within 5 years.
Energy saving technology
1. Air compression system
The discharge pressure of air compressor is reduced from 0.52mpag to 0.42mpag
2. Pre-cooling system
Air cooling tower resistance reduced from 10KPA to 6kpa
The high efficiency and low resistance packing not only ensures the heat exchange performance of the tower, but also reduces the resistance
The new, efficient and advanced distributor is used in the liquid distribution device, which can reduce the amount of cooling water on the premise of ensuring the heat exchange performance of the tower; the gas flux is very high, which greatly reduces the resistance of the internals.
The cooling water unit adopts the small flow and large temperature difference type; the flow of the chilled water pump is reduced by more than half;
3. Purification system
Adsorber resistance reduced from 8KPa to 4kPa
The unit adsorption capacity is increased by 50% when type III molecular sieve adsorbent is selected. With the decrease of regeneration power, the resistance is also reduced
4. Fractionator system
Regular packing shall be used for the lower tower, upper tower and argon tower;
Packing is new type plus; distillation efficiency is increased by 20%
The plate heat exchanger adopts a new structure, and the resistance of the main heat exchanger is reduced from 15kpa to 10KPA
With multi-layer main cooling, the temperature difference of heat transfer can be reduced from 1.6K to less than 0.9k
5. Control system
The flow measurement adopts bar flowmeter, and the resistance is reduced from 3-4kpa to 0.5-1kpa
There is no 11000 specification of air separation in the national standard. The table lists the air separation data calculated by interpolation method:
|
No. |
Name |
Design index |
JB/T8693-2015 |
Practical Operation |
Industry operation |
|
1 |
Air compressor discharge |
0.42 |
-------- |
0.42 |
0.52 |
|
2 |
Air compressor flow |
58000 |
-------- |
57225 |
61000 |
|
3 |
Energy consumption per unit equivalent oxygen production |
0.42 |
0.438 |
0.419 |
0.461 |
|
4 |
Energy consumption compared with national standard |
|
|
95.9 |
105 |
Note: There is no correct to the energy consumption test of air compressor which is 3.29% higher than which under the design condition
It can be tell from the comparison data that the energy consumption of KDON (AR) - 11000 / 20000 / 300 complete air separation equipment supplied by DEAR air separation to Henan Minyuan Special Steel Co., Ltd. is significantly lower than the corresponding national standards. The plant belongs to energy-saving air separation, and is at the leading level in China.
