The GDT Tek Energy System's power generation/co-generation technology is based on the Organic Rankin Cycle principle that involves the harnessing of waste heat having electrical generation and/or mechanical drive capabilities.
The GDT Tek System begins by heating a medium from a liquid to gaseous state through the use of waste (or solar) heat. The System’s absorption method for heat transfer is achieved through various types of heat exchangers or parabolic solar panels (see mechanical schematic drawing numbers 110-0200-01 Solar, Co-Gen w/Chiller and Co-Gen w/o/Chiller).
The System is a closed circuit that begins by transferring heat into the medium, which in turn converts the medium in its liquid form into a pressurized, gaseous form. The gas, passing through Pipe #18 with a mass flow, is then expanded into the chamber of a mechanical apparatus (the “Expander”, Item#20), producing a rotating force that then has the ability to drive mechanical devices. As the mass flow and energy of the gas are consumed and leave the Expander (Pipe#32), the medium begins to condense back to its liquid state. (The lube oil used to lubricate the Expander is then separated through an oil separator (Item#34) from the gaseous mix as it exits the Expander and routed back to an oil reservoir for re-circulation to the Expander.)
The gas from the Expander is taken through a secondary heat exchanger (Item#42) that re-condenses the gas into its original liquid form. The liquid medium is returned via Pipe#44 to a reservoir for eventual pumping back into the boiler loop. The controls for the circuits (Item#58) are primarily utilized for failsafe functions, and for boiler feed pumping control.
The System also include various sub-System loops whose functionality is further described below:
The heat exchange loop (Item#42) re-condenses the heat transfer medium after the Expander uses either a water cooling tower, air condensing coils or a chiller system to remove residual heat, bringing the medium to its optimal expansion capacity for heat transfer back into the Expander.
- After separation from the expended gas, oil returns to a reservoir for pumped re-circulation to the Expander (Pump#36 and Tank #34 to Unit #20). Calculated oil flow provides sealing characteristics for the Expander, optimizing performance in the System. The oil has compatibility characteristics for the heat transfer medium. Clean separation through the separation process is critical, and requires precise heat control on the exhaust of the Expander. This is achieved through the use of precise control of superheat on the boiler feed side of the Expander. The balance required is not losing too much heat through the oil, yet allowing for good oil separation from the heat medium.
- The boiler feed loop uses a frequency drive to control the pumping velocity of the heat transfer medium to achieve the proper critical mass flow to drive the Expander. There are two functions of the frequency drive in this process.
- The first is the Expander’s ability to react to the System’s mechanical mass, which must be precisely maintained in order for the rotating [moment] to maintain the operating speed required to run generators. Generators hooked into a power grid (Item#28) are required to maintain output speed/frequencies as required by electric utilities, plus minus tolerance. The frequency of the generator is checked and adjusted through the use of a programmable logic controller (“PLC”) that feeds its differential control loop back to the driving “frequency drive” to adjust the boiler feed velocity by either speeding up or slowing down the boiler feed loop. This sub-system allows for precise metering of the boiler feed loop and precise generator frequency control.
The second is providing a precise boiler feed control for precise control of mass flow/super heat through the Expander (oil heat requirements). This methodology also allows the elimination of any control valves that normally do not have the reactive precision required for [dithering] a boiler feed loop to control a generator’s output frequency. An additional benefit is the elimination of control valves, which otherwise would restrict the mass flow through the Expander and lower the System’s output efficiency.
The GDT Tek System has very low grade heat requirements in order to produce power. Mass flow potential begins at around 200°F, with the maximum temperature providing the optimum operating conditions for the heat transfer medium reached at only 220°F. Boiler feed velocities can also be increased to match the thermal heat exchange potential in the boiler and/or solar panels. Matching potentials is based on capacity calculations for the Expander.
There are a variety of potential uses for the GDT Tek System. Power generation is just one of many possible applications. Other applications include any mechanical driven devices such as pumps, generators, or anything else requiring a mechanical drive.
The fail-safes for the system are for the protection and safety of potential over pressures as well as for the prevention and destruction of the equipment in the event of subsystem failures. There is also a safety bypass loop built into the boiler loop with a primary blow-off in the event of any over temperature or over pressure conditions that may develop.