Development of a Novel Soft Sensor with Long Short-Term Memory Network and Normalized Mutual Information Feature Selection

Table 3

Candidate input variables of flue gas desulfurization system.

Variable	Description	Unit
1	Generator power	kW
2	#9 furnace original flue gas SO2	mg/m^3
3	#9-1 absorption tower export flue gas SO2	mg/m^3
4	#9 absorption tower gypsum slurry pH
5	Limestone slurry to #9 absorption tower stream	m³/h
6	#9-2 absorption tower pH 1
7	#9-2 absorption tower feed flow	m³/h
8	#9-1 circulating slurry pump current	A
9	#9-3 circulating slurry pump current	A
10	#9 absorption tower entrance flue gas temperature	°C
11	The sum of air flow	CMH
12	The sum of coal	t
13	#9 absorption tower export flue gas temperature 1	°C
14	#9 absorption tower export flue gas temperature 2	°C
15	#9 absorption tower export flue gas temperature 3	°C
16	#9 furnace chimney entrance net flue gas flow	Nm³/h
17	#9 furnace chimney entrance net flue gas pressure	Pa
18	#9 furnace raw flue gas NOx	mg/m^3
19	#9 furnace raw flue gas O2	mg/m^3
20	Median value of desulfurization productivity of unit 9	%
21	#9-2 absorption tower export temperature 1	°C
22	#9-2 absorption tower export pressure	Pa
23	#9-1 absorption tower export flue gas O2	mg/m^3
24	#9 absorption tower level value	m
25	#9-2 absorber tower level	m
26	Water circulation vacuum pump	kW
27	Gypsum slurry outflow pump a current	A
28	#9 gypsum slurry cyclone entrance pressure	Pa
29	Dewatering machine power	kW
30	Gypsum filter cake height	m