Fire pumping station and fire water tank for the combined power plant

The problem

• the need to adapt the pumping stations to the current legal requirements
• the investor cannot afford a downtime or limited fire protection during installation, as this is a critical infrastructure facility supporting a major Polish city

Solution

• we re-equipped the fire-fighting pumping station and carried out a project involving the construction of a fire water tank.
• we had made a temporary bypass at the process water line until the fire water tank was operational.
• we integrated the control and measurement system of the fire-fighting pumping station and the fire water tank with the IT system of the carbonisation control room

After many years, the investor decided to adapt the pumping station to the current requirements of the stipulations included in the Regulation of the Minister of Internal Affairs and Administration of 24 July 2009 on the fire-fighting water supply and fire routes.

In terms of fire-fighting capacity, the pumping station provides the supply of water for external hydrants, internal hydrants and sprinkler systems within the entire site. Its other function is also to supply the washing water system with process water.

Assumptions for the operation of the pumping station

The pumping station was intended to be equipped with two alternately operated fire-fighting pumps and two jockey type pumps for the washing water. The investor expected that the system should operate fully automatically and should not require continuous maintenance.

The fire-fighting pumps are actuated automatically, when pressure drops in the fire-fighting system as a result of a signal sent by the pressure switch:

• in the first instance, at a lower pressure drop (when water is drawn for washing purposes, and the pressure drops down to between 6 and 4.8 bar), the jockey type pumps are operated and stabilise the system pressure,
• during high water intake periods (for fire-fighting purposes – when the pressure drop reaches less than 4.8 bar), the first of the fire pumps is activated,
• the second pump is activated when the pressure drops below 3.6 bar. Both the first and second fire pump continue to run until they are manually switched off.

One of the key functionalities assumed by the investor was the visualisation of the status of the fire-fighting pumping station in the IT system of the carbonisation control room. A signal should be sent to the software transmitting the current operating status of the fire pumps, including fault indication, as well as information on the water level in the fire tank, the positions of critical fittings, the water temperature in the tank and the temperature at the pumping station.

The upgrade of the pumping station required the construction of one of the largest fire water tanks in the Polish industry (900 m3). Due to the complexity of the whole project, the work was divided into two phases, which made it possible to avoid a situation in which the tank start-up would be carried out in parallel with works carried out on the pumping station building itself. This in turn required the pumps to draw water from the existing process network until the reservoir was erected.

Phase 1 – Upgrade of the pumping station

The work in this phase started with project preparation and agreement with the fire safety expert. Given the fact that our works took place at an actively operating site, we could not forget about the need to ensure fire safety throughout the duration of our works. Thus, for the period required to carry out the the switchover from the old to the new equipment, we have developed a procedure for the combined power plant to be used in the case of a fire. The instruction assumed the use of the the existing Diesel standby pump and an additional water supply from the process network.

The next step was the progressing dismantling of the existing equipment and installations, together with the construction of foundations for new pumps in the pumping station building. Once everything was ready, we delivered and installed two fire pumps. (each with the power of 110 kW and the capacity of 250 m3/h) and two washing water pumps (each with a power of 11 kW and the capacity of 27 m3/h). We also supplied all the required fittings and a sprinkler system to protect the pumping station building.

We then proceeded with the instrumentation and electrical installation works. We replaced the power and control switchgear at the pumping station building, followed by the connection of the pump control and status monitoring systems. Once the installation was connected to the carbonisation control room control system, we could proceed with the repairs. We replaced the doors to the pumping station building, the lighting and electrical installation, and carried out the necessary painting work.

Due to the aforementioned division of the works into two phases (pumping station and water tank), we also made a temporary bypass connection. It enable the alternative supply of the softened water system with the new fire-fighting network until the time the fire water tank was ready. Once the works were completed, we proceeded with the commissioning of the pumping station and training of the combined power plant staff in its operation.

Stage 2 – Fire-fighting water tank

We selected a ground cylindrical steel tank made of galvanised sheet metal according to detailed calculations. The tank has been placed in the direct vicinity of the upgraded pumping station building, on foundations, the ordinate coordinate of which corresponds to the level of the ordinate coordinate of the floor inside the pumping station building. The design, insulation and equipment of the tank comply in turn with the requirements of the PN-EN standard.

Basic parameters::

• tank diameter: d = 10.873 m
• tank height: h = 10.850 m
• working volume: V = 900 m3

We started the delivery and assembly of the fire water tank by obtaining the building conditions, followed by the construction permit. Once all the formalities were complete, we proceeded with designing the foundations for the tank. At the end of the design work, we started the earthworks intended to cast the foundations, including the designed reinforcements. We then moved on on to the tank assembly, together with the control and monitoring system, and then the tank was connected to the fire-fighting water system and filled. The legal requirement required the tank to be filled within a maximum time of 48 hours.

From the point of view of the investor, the commissioning of the pumping station system and fire tank installation in their final forms were the key point in the project. The switchover of the pump supply from the previously constructed bypass to the water in the tank had to be closely coordinated with the work schedule and the operation of the combined power plant, as we could not afford a decrease in the fire protection levels of the plant during these works.

Once the switchover was successfully completed and the installation was commissioned in its final form, we proceeded with training of the combined power plant staff in the operation of the entire installation, followed by the hand-over of the as-built documentation.

Safety first

In all projects we undertake, we pay particular attention to the safety of our staff and subcontractors. Therefore, during the implementation of this project, we also adhered to the principles strictly agreed upon with the investor:

• The construction works were carried out on the basis of a consulted SWM document
• All the staff have received the required health and safety training
• We have appointed a health and safety coordinator
• We have meticulously followed the rule that all the staff should have the required licences, professional qualifications and have undergone workplace-specific training.
• All Phase 1 work was carried out according to written work orders
• On the other hand, Phase 2 works were carried out on the basis of the planning permission.

One of many projects for this investor

The described upgrade project for the fire pumping station and the delivery of a 900 m3 fire tank was just one of many projects we have carried out for the aforementioned investor. Our past projects have included:

• ATEX: Comprehensive explosion protection for biomass feeding systems
• Fire safety: Sprinkler protection for the inclined bridge
• Fire safety: Fire-fighting water tank and pumping station.
• Fire safety: Upgrade of the internal hydrant system
• ATEX: Comprehensive explosion protection for 13 conveyor belts
• ATEX AND FIRE CONSULTANCY: Demonstration of the wide range of fire and explosion hazards related to the fed fuel