As an engineering firm, ENGINEERIK have successfully utilized Bentley WaterGEMS and Bentley Water Hammer software tools to develop hydraulic water models and optimize water system performance from the perspective of efficient and sustainable management.
Using Bentley WaterGEMS, we create accurate hydraulic models, analyze system behavior, and evaluate different scenarios to optimize the operation of water supply and distribution networks. With this software, we can identify inefficiencies, minimize water losses, improve pressure management, and ensure a reliable water supply to our clients. By leveraging WaterGEMS, we have been able to streamline water distribution systems and achieve significant improvements in efficiency and cost-effectiveness.
Additionally, we rely on Bentley Water Hammer to analyze and address transient events like water hammer in water distribution systems. By modeling and simulating these events, we can identify potential issues and implement measures to prevent equipment damage and inefficient system operation. This proactive approach has helped us ensure the longevity and resilience of the water systems we manage, minimizing disruptions and maintenance costs.
The scope, as defined in the client’s requirements, for the project in which we utilized both Bentley WaterGEMS and Bentley Water Hammer software tools is as follows:
- The project involves the reconstruction of a part of the water distribution network in the village of Aydemir, with a total length of 10.31 km (ranging from DN90 to DN315), as well as the reconstruction and construction of 722 building service connections and 1 PRV chamber. The pipes intended for reconstruction are made of polyethylene (HDPE) PN 10.
- The project involves the reconstruction of a part of the water distribution network in the village of Kalipetrovo, with a total length of 10.19 km (ranging from DN90 to DN250), аs well as the reconstruction and construction of 551 building service connections, 4 meter chambers, and 1 PRV chamber. The pipes intended for reconstruction are made of polyethylene (HDPE) PN 10.
- The project also includes the reconstruction of water mains pipelines for the agglomeration Silistra, which includes village of Aydemir and village of Kalipetrovo, with a length of 8.04 km and diameters ranging from DN200 to DN500mm. It involves the construction of 2 water meter chambers, 6 wastewater valve chambers, and three surge tanks. The pipes intended for the construction of the water distribution network in this area are made of PEHD PN 16/10. The project scope also encompasses various activities related to the following facilities:
- Wells: Type “Ranei” 1, 4, and 5
- Pumping station (PS) II
- High-level reservoir 3000m3
- High-level reservoir 400m3
- Water tower (WT) Kalipetrovo
Furthermore, the project includes the construction of new chlorination stations near Wells Ranei 4, 6, 8, and PS II.
Figure1. Siteplan of reconstruction of the water distribution network in an agglomeration including water main pipelines.
In our project, we have thoroughly examined the importance of the collaborative operation of the pump-pressure pipeline system to protect against the negative impacts during hydraulic water hammer events.
Hydraulic water hammer in the pump-pressure pipeline system.
The sudden shutdown of the pump units generates a pressure wave of reduced pressure ψ. The pressure at each section of the pipeline depends on the interference of direct and reflected waves at the junction and varies over time. The reduced pressure waves are generated by the pump, which continues to operate by inertia after the sudden power outage, gradually decreasing its flow rate and pressure. When the pump stops supplying water in the original direction, the check valve installed in the pumping station closes. At this moment, the reflected high-pressure waves from the reservoir encounter the closing device and are reflected back as high-pressure waves.
Depending on the specific terrain conditions and hydraulic system parameters, a vacuum can be formed in a section along the route of the pressure pipeline due to the decrease in the pressure head (resulting from the pump units’ shutdown). When the vacuum exceeds 8-9m, the water jet can practically experience a cavitation, which is highly dangerous for the integrity of the pipeline. Sequential encounters of cavitated water columns generate a pressure significantly higher than the pressure at the most unfavorable section in a water hammer event without cavitation (occurring in gravitational pressure pipelines).
In the general case, the possibilities of water jet cavitation depend on the magnitude of the static head Hst in the system, the inertial moment of the rotating parts of the pump units, the pipe dimensions and materials, the properties of the water (including the amount of dissolved air), and especially the longitudinal profile along the pipeline route.
Hydraulic water hammer is most dangerous and significant in long, straight pipelines with a consistent characteristic throughout their length. In a pipeline with different characteristics or branches from the main pipeline, such as deviations with smaller diameters for different streets, the hydraulic water hammer decreases significantly due to multiple partial reflections of the shock waves at these deviations, which interfere with each other.
During sudden power outages (in case of emergencies), the Q-H characteristic of the pump changes according to a law dependent on the variation of the rotational frequency of the units Ƞ.
Figure 2. Transient Result Viewer by Bentley Hammer for water mains 1(one of the several water mains), without protection.
By coordinating the operation of the pump and the pressure pipeline, we aim to minimize the occurrence and severity of water hammer. The pump’s controlled shutdown and startup procedures, along with the appropriate opening and closing of valves and check valves, play a critical role in reducing the sudden pressure variations and subsequent water hammer effects.
In the context of our specific project, undertaken by ENGINEERIK, we have thoroughly examined the importance of the collaborative operation between the pump and pressure pipeline system to mitigate the negative effects associated with hydraulic water hammer.
To address water hammer concerns, we have implemented various strategies and measures. Firstly, we have carefully selected pump units and equipped them with frequency control capabilities and soft starterts. This enables smoother pump operation and minimizes abrupt pressure fluctuations, thereby reducing the likelihood of water hammer incidents, as is described below:
- Pump units with high inertia and frequency control: By incorporating pump units with large rotational inertia, along with frequency control mechanisms, the sudden changes in flow rate and pressure can be minimized. The frequency control allows for gradual adjustments in pump speed, reducing the likelihood of water hammer occurrences.
- Pump units with frequency control: Pump units equipped with frequency control alone can also contribute to mitigating water hammer. The ability to regulate the rotational speed of the pump according to the system’s requirements helps in maintaining a stable flow and pressure, reducing the risk of water hammer events.
- Pump units with soft starters: Soft starters facilitate a gradual and controlled acceleration of the pump units, preventing abrupt pressure surges and minimizing water hammer. By gradually increasing the speed and flow rate, the likelihood of water hammer-induced damage is significantly reduced.
Implementing these approaches and utilizing pump units with specific features like high inertia, frequency control, and soft starters helps to effectively reduce the occurrence and intensity of hydraulic water hammer events in pump stations and associated systems.
Figure 3. Pump units with soft starters
To provide an additional layer of protection, we have employed various techniques such as redirecting the water back into the reservoir through pressure regulators and introducing air into the system via vacuum breakers. These measures help alleviate excess pressure and dissipate energy, effectively managing water hammer effects.
Figure 4. Redirecting the water back into the reservoir through pressure regulators
Additionally, in one of the several pressure pipeline mains we have implemented protective measures such as surge vessels, air chambers, and pressure relief valves strategically placed within the system. These components help absorb excess pressure, dissipate energy, and provide relief during water hammer events, safeguarding the system from potential damage.
Bentley Water Hammer, as part of the Bentley software suite, offers a valuable tool for analyzing and mitigating vacuum conditions in the system, particularly in relation to the implementation of vacuum breakers. Vacuum breakers play a crucial role in preventing the formation of damaging vacuum pressures within the pipeline system.
By incorporating vacuum breakers into the design, the system benefits from a reliable and cost-effective solution. Vacuum breakers are designed to release air into the system, effectively breaking the vacuum and maintaining pressure equilibrium. This prevents the occurrence of excessive vacuum pressures that could lead to pipe collapse or water column separation.
The use of vacuum breakers offers several advantages in various scenarios. Firstly, during the initial design phase, the inclusion of vacuum breakers allows for a more streamlined system layout. By mitigating the risk of vacuum formation, it reduces the need for over-engineering or the installation of additional expensive reinforcement measures. This can result in significant cost savings in terms of initial capital investments.
Furthermore, vacuum breakers contribute to the smooth and efficient operation of the system during its lifecycle. By preventing vacuum-related issues, such as pipe collapse or water column separation, they ensure the system’s longevity and minimize the potential for disruptive downtime and costly repairs.
With the help of Bentley Water Hammer software, engineers can accurately model and simulate the behavior of vacuum breakers within the hydraulic system. This enables them to optimize the placement and sizing of vacuum breakers, ensuring their optimal performance in preventing vacuum-related incidents.
Figure 4. Vacuum Breaker
Figure 5. Transient Result Viewer by Bentley Hammer for water mains 1(one of the several mains), with protection.
Furthermore, our team has utilized advanced software tools like Bentley WaterGEMS and Bentley Water Hammer to model and simulate the hydraulic behavior of the pump-pressure mains together with internal water supply pipeline system of the two sites. These software solutions enable us to accurately analyze and predict potential water hammer scenarios, allowing us to optimize the system’s design, layout, and operational parameters to minimize water hammer risks in the water mains and еntry points of the water distribution networks in the analyzed two populated areas within the specific project.
However, it is equally important to address surge protection at the entry points of the water distribution networks in the analyzed populated areas. Here, the sudden changes in flow velocity and pressure can affect the internal water distribution system, potentially causing pipe failures, leaks, and disruptions in water supply to residential, commercial, and industrial consumers.
To mitigate the negative effects of hydraulic shock at the entry points of the water distribution networks, appropriate surge control measures was implemented. This included the use of surge tanks, pressure relief valves, air valves, and check valves strategically placed within the network. These devices helped absorb and control the pressure surges, minimizing the risk of damage to the distribution pipes and ensuring a reliable water supply to the local communities.
By analyzing the hydraulic behavior of the water distribution systems using advanced software like Bentley WaterGEMS and Water Hammer, we at ENGINEERIK could accurately model and
simulate the occurrence of water modeling effect. This allows for the optimization of surge control measures, ensuring their proper sizing, placement, and functionality to effectively mitigate the negative surge impact.
Through our meticulous design and utilization of advanced software tools like Bentley WaterGEMS and Bentley Water Hammer, we have accurately modeled and simulated the hydraulic behavior of the pump-pressure pipeline system specific to the project. This comprehensive analysis has allowed us to optimize the system’s layout, hydraulic parameters, and operational strategies, ensuring effective water hammer prevention and minimizing its potential impacts.
By implementing these tailored approaches and leveraging advanced software solutions, ENGINEERIK has successfully addressed the challenges posed by hydraulic water hammer, ensuring the reliable and efficient operation of the pump and pressure pipeline system for our specific project.