Process Description
The SPM-800 Centrifugal Pump Process Simulation can be configured to pump
any liquid by varying liquid density. Upstream and downstream pressures
may also be varied. The default configuration pumps water from an atmospheric
upstream pressure to an atmospheric downstream pressure.
Two pumps are provided. The pumps may be operated independently or in parallel.
A recirculation line is provided to maintain flow through the pumps in the event that the flow controller completely closes.
Approximately 250 GPM of water is to be pumped from one location to another
at a constant pump speed of 3500 RPM and a discharge pressure of 32.4
PSIG.
Each of the two pumps, valved in parallel, is rated at 20 horsepower and
is capable of pumping a maximum of approximately 500 GPM of water at 5000
RPM and a head of approximately 30 PSI. Together, both pumps can displace
approximately twice the volume at 5000 RPM and a head of approximately
60 PSI.
All the control valves in the system have linear flow characteristics.
Each pump is outfitted with a START/STOP switch (HS-101 and HS-102), a
speed controller (SIC-101 and SIC-102), a horsepower indicator (HP-101
and HP-102), and a pump efficiency indicator (EFF-101 and EFF-102).
At constant pump speed, flow may be controlled with flow controller FIC-101. In the event of a control valve failure, flow may be controlled by modulating the bypass valve HIC-101.
The recirculation flow (FI-102) is modulated by the pump discharge pressure regulator PIC-102.
Upstream
and downstream pressures are indicated by PI-101 and PI-103 respectively.
Typically, flow is controlled by modulating the flow control valve (FIC-101). In this type of configuration, the pump would run at constant speed (SIC-101 and SIC-102). In many instances, a discharge pressure regulator (PIC-102) would be provided to modulate the flow (FI-102) through a recirculation line. The pressure regulator (PIC-102) would maintain a safe discharge pressure and prevent damage to equipment in the event that the flow control valve (FIC-101) completely closed. This is the default configuration.
Alternatively, some pumps are provided with a variable speed control (SIC-101 and SIC-102) to modulate the flow (FIC-101). To configure this type of arrangement, the instructor must completely fail flow control valve FCV-101 from the fault display and the hand control valve HCV-101 must be opened. Flow may controlled by adjusting the speed controller setpoint (SIC-101 and SIC-102) or by cascading the output of the flow controller (FIC-101) to the speed controller's setpoints (SIC-101 and SIC-102) in a master-slave type arrangement.
The second pump may be used as a spare, or both pumps may be operated in parallel to increase the pumping capacity of the system.
All faults can be failed high or low to any degree with any of 8 fault
function generators (step change, square wave, staircase, stairs, ramp,
sawtooth, slope, or sine wave). Faults can be programmed to start and/or
stop at various times during a simulation exercise.
- Fault 1: Pump One Speed %
- Fault 2: Pump Two Speed %
- Fault 3: FCV-101 %
- Fault 4: HCV-101 %
- Fault 5: PCV-102 %
- Fault 6: PI-101 Suction
- Fault 7: PI-103 Process
- Fault 8: Density #/ft3
- Fault 9: FC101 Transmitter
You may create a virtually unlimited number of scenarios and training exercises by programming the faults described in the previous section. You can then establish performance standards for each one of those exercises. Simtronics provides a number of exercises with established performance standards for each process simulation. The objective, time to complete the exercise, cause, effect, solution, and procedure for each exercise is documented. You may modify these procedures to more closely reflect your particular process plant operating procedures.
- Exercise 1: Design
- Exercise 2: Cold Start
- Exercise 3: Primary Pump Fails
- Exercise 4: Flow Control Valve FCV-101 Ramps Closed
- Exercise 5: FIC-101 Flow Transmitter Fails