Project Purpose

The objective of this project was to conduct an hydraulic transient analysis for a high-pressure hydropower pipeline. The analysis aimed to quantify the effect of adding an air inlet valve installed downstream of the transition from a grout-lined tunnel to steel penstock, and to inform operational procedures for ramping plant flow in pipe rupture scenarios.

Project Scope and Methodology

Data Collection and Preparation

1. System Configuration Review: Detailed information on the pipeline system, including layout, dimensions, material properties, and operating conditions, was collected and reviewed.
2. Hydraulic Data Integration: Integrated key hydraulic parameters, such as flow rates and pressure data from observed load rejection and plant shutdown scenarios to calibrate the hydraulic model.

Steady-State Analysis

3. Model Calibration: Conducted a thorough steady-state analysis to establish baseline conditions for pressure and flow within the pipeline system, calibrated against observed plant operation data.

Transient Event Simulation

4. Scenario Development: Developed various pressure transient scenarios, including pump start-up/shutdown, valve closure/opening, and pipe rupture, to simulate potential hydraulic transients due to changing geometry and more generally flow acceleration.
5. Transient Analysis: Advanced hydraulic modeling software was used to simulate the transient events, capturing pressure surges, water hammer effects, potential cavitation, and potential negative gauge pressures along the full conveyance system profile.

Surge Protection Analysis

6. Protective Devices Evaluation: Modelled the behaviour of existing surge protection devices, and evaluated the capacity of a one-way air intake valve against rapid flow acceleration under pipe rupture scenarios of varying degrees of severity.
7. Comprehensive Report Preparation: Compiled the analysis results, including transient event simulations, stress analysis, and surge protection evaluations, into a detailed report.
8. Operational Recommendations: Provided operational guidelines and maintenance recommendations to minimize transient impacts and ensure long-term pipeline safety.

Project Outcomes

9. Enhanced Safety and Reliability: The project ensured the high-pressure hydropower pipeline's operational safety and reliability by identifying and mitigating potential transient events.

10. Detailed Transient Analysis Report: The comprehensive report provided actionable insights and recommendations for maintaining pipeline integrity and avoiding catastrophic failures.

Informed Decision-Making: The findings support informed decision-making for pipeline operation, maintenance, and future upgrades, ensuring sustained performance and safety.