4 Variables model

IAF has designed and developed these educational industrial systems, located at E2 Room in Engineering Building II (University of León). These plants, with intelligent industrial instrumentation for measurement and control of flow, level, pressure and temperature, are used to test control strategies. The Remote Laboratory of Automatic Control (LRA-ULE) provides remote access through the Internet to these industrial models.
Maqueta 4 Tanques

The tanks, pipes, tools, drive and control cabinets are mounted on a stainless steel frame (2mx2m). The design intends that the operation is quick for both SISO and MIMO systems. The drives of all valves are electric, while the drives of the pumps have variable frequency. It has three solenoid valves with variable drives and one of them is on-off. The on-off valve is used to control the rate of processing tank drain, whereas the other 3 valves have variable actuators and are used to regulate the supply of process fluid, to regulate the supply of hot fluid and to regulate the supply from of cold fluid. The model also has two pumps, one to impulse the fluid of the heating tank, which has a frequency inverter to control 3-position through an analog signal, and another to impulse the process fluid, which has a frequency inverter (MicroMaster Vector Siemens) to control the flow.

SUPPRESS research group © from University of León designed and developed this system.

Content

The design of the plant aims to achieve:

  1. Mobility: The scale models are mounted on a wheeled panel and all the elements are electric. Only water intake and drainpipe are required.
  2. Flexibility for control: They can be controlled using PLCs, DCSs, PCs or SCADAs.
  3. Remote access via the Internet: They have automatic lock-out mechanisms to ensure safe remote operation.
  4. Broad range of applications: They can be configured to run either basic control experiments or advanced multivariable control, thanks to the interactions that can be set up among the different control variables. Batch operation of the plants using specific applications was also taken into account.

Each plant is composed of the following circuits:

  1. Process circuit: Including pressure, flow, temperature and level variables.
  2. Hot water circuit: It includes the necessary elements to heat water.
  3. Cooling circuit: Heat is transferred to the process circuit.

Fact Sheet

  • PRESSURE CONTROL
    • Sensor: Intelligent Pressure transmitter 4-20mA+HART.
    • Actuator: Vectorial frequency inverter acting on centrifugal pump.
    • Basic PID control algorithm.
    • Three operation modes: MANUAL, AUTO and REMOTE.
    • Measured variable: Barg.
  • FLOW CONTROL
    • Sensor: Intelligent electromagnetic flow transmitter 4-20mA+HART.
    • Actuator: Electric 2-way valve with positioner.
    • Basic PID control algorithm.
    • Three operation modes: MANUAL, AUTO and REMOTE.
    • Measured variable: l/h.
  • LEVEL CONTROL
    • Sensor: Transmisor de nivel ultrasónico inteligente 4-20mA+HART.
    • Actuator: 2-way electrovalve.
    • Basic PID control algorithm.
    • Three operation modes: MANUAL, AUTO and REMOTE.
    • Measured variable: %.
  • HOT WATER TEMPERATURE CONTROL
    • Sensor: Intelligent ultrasonic level transmitter 4-20mA+HART.
    • Actuator: Static variable drive for heating resistor.
    • Basic PID control algorithm.
    • Three operation modes: MANUAL, AUTO and REMOTE.
    • Measured variable: ºC.
  • PROCESS TEMPERATURE CONTROL
    • Sensor: Intelligent temperature transmitter 4-20mA+HART with probe PT-100.
    • Actuator: In split-range with two electric 2/3-way valves with positioner.
    • Basic PID control algorithm.
    • Three operation modes: MANUAL, AUTO and REMOTE.
    • Measured variable: ºC.

Interactive Zone

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HOT WATER RECIRCULATION PUMP
SEDICAL TF 110 pump equipped with a three-positions frequency inverter to control it with an analogue signal (min-1450 l/min, medio-2000 l/min, max-2100 l/min). This pump is used to achieve homogeneous heating in the fluid that is in the heating tank.

PROCESS PUMP
BSEDICAL pump equipped with a frequency inverter to control it with an analogue signal. This pump provides a flow of 3200 l/h with a hydraulic head of 5.5 m. Its power is 0.5 Hp and their voltage and current values are 230-400 V and 1.2-0.7 A respectively.

FLOWMETER
SITRANS FM electromagnetic flowmeter (Siemens). In the sensor coils are generated a steady magnetic field. The fluid flowing through the sensor induces a voltage proportional to fluid velocity.

LIQUID TANK
This model has two tanks of liquid: one is used to store the process fluid when the entire system is idle and the other tank is used to control the level of it.

HEATING TANK
Stainless steel tank that heats the process fluid. In this tank are installed a thermostat and heating elements.

DIGITAL SOLENOID VALVE
Digital Solenoid Valve SMC 24VDC located in the process fluid tank. It is used to control the flow of drainage of such deposit and create disturbances in the filling and emptying whenever you want.

PROCESS SOLENOID VALVE
Samsom valves 3226-3770 with Samsom positioner 3760 that allows regulation of the opening by an external signal. These valves are responsible for distributing the flow through the tanks. On failure, return to zero position.

EXCHANGER
Plate heat exchangers that allow the temperature exchange between the process fluid and the heating fluid. This allows us to modify and to control the process fluid temperature.

LEVEL SENSOR
PROBE ultrasonic sensor (24 VDC) used to measure the level (0-100%) in the process fluid tank.

PRESSURE SENSOR
SIEMENS pressure sensor used to measure and to control the fluid pressure.

TEMPERATURE SENSOR
Temperature sensor that allow the measure of the process fluid temperature, the heating fluid and the temperature in the exchanger.

OVERVIEW OF THE MODEL