PSL has a large test bed designed to simulate the hot water drilling system used in the IceCube project. This doubles as a large space with an abundance of electrical supply, a series of flexible water manifolds, and a robust controls and sensor system. In this space PSL is capable of testing new applications and tools for the IceCube hot water drill, including actual drilling with the drill tower and borehole. It is also used as a training facility for season preparations with the drill team.
The system has one high pressure pump (2) with the same 50 horsepower motor as used at the South Pole and is capable of 60 GPM and 1200 psig. There is an accumulator and pressure relief valve at the pump outlet. The tesbed has a flowsplit because the high pressure pump cannot run slow enough to provide flow for only 2 heaters. Excess flow branches off and goes back to the water tank sending the rest of the water to the heaters. The system is pressurized by closing the valves on the excess flow manifold.
The heater in the system (item 4) is 1 Model 75 heat (similar to the 39 heaters used on the ICU drill system). In addition to the thermal system the test bed has a tower built identically to the 2 that are used in the drill system for testing and development in realistic scenarios with cables, hoses and reels. There is an 18″ diameter borehole down to 50 feet then an addition 200 feet of depth with a 10″ diameter.
Microturbine
In an effort to develop an innovative power generation system for the next generation of hot water drilling, PSL had invested in a 200 kW Capstone Microturbine. The intention is to develop a 1 MW system by combining 5 microturbines and synchronizing their 480 Vac outputs. The system has an exhaust heat recovery system that provides supplemental heat to the water tanks. Testing results have demonstrated the heat exchanger can capture up to 1.3 times the output of the engine in thermal energy. Integrating this system into the testbed and drill provides more efficiency, fuel flexibility and reliability than typical piston generators. Additionally the system offers fast start times, compatibility with AN-8 jet fuel and diesel.
