Doosan Škoda Power is a leading supplier of advanced systems, components and services in the fields of design and power generation. Our service expertise includes retrofits and modernization (R&M) of existing installed equipment, commissioning and long-term service, including a supply of spare parts.
Alongside the production of our own turbines, Doosan Škoda Power's R&M Department specializes in turbine retrofits and upgrades of the products manufactured by all global producers. The services we provide for our customers worldwide are individually tailor-made.
Modern turbine control and protection systems are fully integrated within the DCS. We use many different control systems when we upgrade turbines.
A redundant electronic system ensures the control of the basic physical values. The output from this system drives the HP and IP turbine stop and control valves, as well as other actuators in the turbine island systems.
A redundant electronic system protects the steam turbine. If certain conditions occur, the system shuts down the steam turbine at the HP and IP stop valves.
The upgrade of a turbine hydraulic control system is designed for all types of steam turbines. A hydraulic high-pressure control system drives all control, stop and extraction steam valves of servomotors (actuators). Pressure oil is delivered by an HP supply unit. Emergency stop valves supply inlet steam to the turbine. Single-acting, two position (close/open) hydraulic actuators control the positions of the valves. HP control valves modulate the flow of steam into the turbine. Their positions are set by one single-acting linear hydraulic actuator. The precise position is provided by an electronic positioning control loop. The non-contact linear transducer (LVDT) closes the positioning loop as a feedback signal. Thus, a very high control quality and position accuracy is achieved.
A hydraulic supply unit is a basic part of all HP hydraulic systems. It provides a continuous, reliable supply of high-pressure control oil to all actuators in stop and control valves. A double pump supplies control oil at nominal pressure of 16 Mpa, as well as filters and cools the oil. One of the two pumps runs and feeds the control oil into the system, the other one serves as a reserve pump. Bladder-type accumulators at the system’s outlet provide a readily available source of hydraulic fluid to meet the large transient demand for fluid, as well as maintain the system’s pressure during an emergency start of the standby pump.