Automation system for controlling heating substation

Scope of Work

Roking provided detailed and as-built electrical design, developed PLC application software for Siemens ET200SP and developed application for Weintek HMI. Commissioned the system and trained personnel.

Benefits

• Automatic control of heating and ventilation in the object based on set parameters
• Process visualization, operation and display of alarms, warnings and operator messages via HMI
• Automatic mode of work based on calendar scheduler, with option to select non-working days
• Optimization of the circulation pumps start, based on pump runtime

Technical Description

Heating substation has two individual heating circles: floor heating and radiator heating.

Radiator heating is achieved with hot water coming from remote heating plant. Temperature of incoming water is measured. Circulation of water is done by two redundant pumps. At start up of radiator circle, the pump with lower runtime is declared as running pump. Radiator circle is started when the measured temperature of incoming water is greater than the set threshold for automatic start.

Floor heating circle has a choice of heat source selection: heat pump or remote heating plant. Temperature of water in the system is set automatically based on the measurement of the outside temperature sensor, called sliding. Based on the choice of heat source selection, there are two cases:

Heat source: remote heating plant

Floor heating is achieved with hot water coming from remote heating plant. System is started automatically when the measured temperature of incoming water is greater than the set threshold for automatic start. At start up of floor heating, one of the two circulation pumps is started and three-way electromotor valve regulates temperature of water in the system to the set temperature via sliding of the outside sensor. Regulation of the valve is achieved via PID control, based on measurement of the temperature sensor.

Heat source: heat pump

Floor heating is achieved with hot water coming from local heat pump. System is started automatically by calendar or by operator via HMI. At startup two of the four circulation pumps are started and three-way electromotor valve regulates temperature of water in the system to the set temperature via sliding of the outside sensor. Regulation of the valve is achieved via PID control, based on measurement of the temperature sensor.

Beside floor heating and radiator heating, automation system regulates the temperature of air in ventilation channels. Heating of air is done by two recuperators, and regulation of air temperature is achieved via regulating electromotor valves, applying PID control on them based on measurement of the temperature sensors in ventilation channels.