Application of variable frequency drive on the condensate pump motors of APR1400 nuclear power plants for energy savings

Figures & data

Figure 1. APR1400 Condensate system.

Figure 2. Variable frequency drive control.

Table 1. Effects of reduced speed on required power.

Pump speed	Mechanical Power required
100%	100%
90%	73%
75%	42%
50%	13%

Table 2. The proposed VFD specification.

Product or component type		Medium Voltage VFD data
Number of Phases		3 phases
Supply Voltage		13.8 kV
Supply frequency		50/60 Hz
Output voltage		13.8 kV
Rating		4440 kVA
Power factor		80%
Operating efficiency		95%
Nominal Continuous Current	Standard Overload 120%	162 A
	High Overload 150%	129 A
Dimension (W*D*H)		6870x1500x2670 (mm)
Approx. weight		9100 kg

Table 3. Condensate pump specification.

CONDENSATE PUMP
Pump Type	Vertical, Centrifugal, Can type, Mixed flow.
Quantity per unit	3
No. of pumps in operation	2
No. of pumps in standby	1
No. of stages	3
Minimum recirculation flow	5000 gpm
Motor Voltage/Phase/ Frequency	13.2 kV/3Phase/60Hz
Rated Capacity/flow	(12,700 gpm) 48,075 L/min
Rated head	(1,010 ft)305 m
Motor rated horsepower	3,432 kW (4,600 hp)
Pump rated speed	1180 rpm
Recirculation flow VS. rated flow	40%
Pump motor type	AC induction
Efficiency at 100%	95.5% at 0.88 PF
Efficiency at 75%	95.3% at 0.87 PF
Efficiency at 50%	94.4% at 0.83 PF

Figure 3. CP input data and loading condition in ETAP.

Figure 4. VFD input and output data in ETAP.

Figure 5. Illustrate the current configuration.

Figure 6. Illustrate the proposed configuration.

Figure 7. The results of simulation in the current operating conditions.

Figure 8. The simulation results with VFD.

Table 4. Shows the calculation results.

CALCULATION RESULTS
WITHOUT VFD	Motor Input Current = 134.5 A(Field data)
	Power Factor = 87 % (data sheet)
	Motor Input Power = 2675 kW
WITH VFD	Motor Input Current = 97 A
	Power Factor = 84 %
	Motor Input Power = 1955 kW
	VFD Input Power = 1961 kW

Table 5. Harmonic results in bus N 1E 821-E-SW02M.

BUS N 1E 821-E-SW02M	THDv (%)	kVrms
Without VFD (Bypass mode)	6.86	13.81
With VFD	7	13.84

Table 6. Harmonic results in the main transformer.

MAIN XFMR	THDv (%)	Arms
Without VFD (Bypass mode)	2.99	1970
With VFD	2.99	1970

Table 7. The comparison between the simulation results and the results obtained from the calculation.

ETAP SIMULATION RESULTS		CALCULATION RESULTS
WITHOUT VFD	Motor Input Current = 130.7A	134.5 A (Field data)
	PF = 86.99 %	PF = 87 % (datasheet)
	Motor Input Power = 2712 kW	2675 kW
WITH VFD	Motor Input Current = 106 A	97 A
	PF = 83.99 %	84%
	Motor Input Power = 2042 kW	1955 kW
	VFD Input Power = 2149 kW	1961 kW
RATIOS	I: $\frac{106A}{130.7A}=81\mathrm{\%}$	I:$\frac{97A}{134.5A}=72\mathrm{\%}$
	P: $\frac{2042kW}{2712kW}=75\mathrm{\%}$	P: $\frac{1955kW}{2675kW}=73\mathrm{\%}$
	VFD Efficiency: $\frac{2042kW}{2149kW}=95\mathrm{\%}$	95 % (VFD data sheet)
POWER SAVING	720 kW (27 % saving)
ANNUAL ENERGY SAVING	10,091.52 MWh for two CPs
ANNUAL COST SAVING	504,576 USD for two CPs