Description:The invention proposes a retrofit module appended downstream of the draft tube of an existing turbine system. The invention utilizes water discharged from the main turbine to drive a hydraulic pressurization system and an auxiliary water-jet turbine that boosts the main shaft torque.
Key elements of the system include:
• A water collection reservoir or chamber connected to the draft tube outlet.
• A hydraulic piston-cylinder assembly actuated using water as both the pressurizing and working fluid.
• A mechanically governed unidirectional flow system, allowing cyclic transfer of water from the upper chamber to the cylinder's lower side.
• A counterweight or equivalent mechanism to aid piston retraction.
• A nozzle and jet system integrated at the bottom of the cylinder to generate a pressurized water jet during the piston’s power stroke.
• A compact jet-turbine aligned to transfer torque directly or indirectly to the main turbine shaft.
Multiple such hydraulic modules operate in coordinated cycles to provide continuous and cumulative torque to the existing turbine shaft, thus enhancing generator performance without altering the main turbine geometry.
, C , Claims:Disclaimer: The following indicative claims are included in the provisional specification to broadly outline the scope of the invention. Formal claims will be submitted in the complete specification as per Section 10(4) of the Patents Act, 1970.
1. A retrofit hydropower enhancement system comprising a piston-cylinder assembly powered by gravitational water pressure from the draft tube discharge, wherein the system is configured to convert potential energy of post-turbine water into additional mechanical torque on the main turbine shaft.
2. The system of claim 1, wherein the piston-cylinder assembly includes a top-mounted water chamber, a hollow piston shaft, and at least one unidirectional flow mechanism facilitating water transfer during upward and downward piston strokes.
3. The system of claim 2, wherein the downward piston stroke is driven by gravitational potential energy of the water in the top chamber, generating a high-pressure water jet at the bottom of the cylinder.
4. The system of claim 3, wherein the pressurized jet is directed toward an auxiliary jet turbine coupled to the main turbine shaft, thereby increasing total torque without modifying the primary runner.
5. The system of claim 1, wherein the upward piston stroke is mechanically assisted by a counterweight system or equivalent gravitational reset mechanism to allow for passive water transfer and recharge.
6. The system of claim 1, wherein multiple such piston-cylinder modules operate in a staggered sequence to provide continuous torque assistance to the main shaft, optionally stabilized by a mechanical flywheel.
7. The system of claim 1, wherein the discharged water is first collected in a secondary reservoir equipped with a sediment filtration system, allowing clean water to feed the hydraulic modules and reduce wear on internal surfaces.
8. The system of claim 1, wherein the auxiliary torque generated contributes up to a 70% increase in net output power from the existing turbine using the same hydraulic head and flow rate.
9. The system of claim 1, wherein the retrofit is applicable to both Kaplan and Francis turbines and is adaptable without structural modification to the existing runner, penstock, or generator infrastructure.
10. A method for retrofitting existing hydropower turbines, comprising:
(a) collecting post-turbine water discharge,
(b) channelling the water into at least one gravity-fed hydraulic piston-cylinder module,
(c) generating a pressurized water jet during piston descent,
(d) directing said jet to a secondary turbine mechanically coupled to the main turbine shaft, and
(e) repeating the process cyclically using multiple modules to produce continuous torque enhancement.