How a Turbophase Module Makes Air More So Efficiently
Turbophase is a packaged system with a reciprocating engine driving a multi-stage, intercooled centrifugal air compressor. Air is drawn into system to ventilate the system and provide air to the compressor. The compressor air filtration system mirrors the air quality of the gas turbine and then is compressed by the first stage of the air compressor and then cooled. The inter-cooled process is repeated through four or five stages, depending on the desired pressure, resulting in less power required per pound of air compressed compared to the axial compressor in a gas turbine. After the final stage of compression, the compressed air flows directly into the recuperator, a heat exchanger which transfers the waste heat of the reciprocating engine exhaust into the compressed air. The Turbophase module has now generated air at gas turbine compressor discharge pressure and temperature about 30 to 40% more efficiently than the gas turbine itself.
The Challenge for Gas Turbines
Gas Turbines draw ambient air into their axial flow compressor, increasing the temperature and pressure of the air. The air then flows into the combustor where fuel is added proportionate to the amount of air mass flow and the mixture is ignited. This high-energy gas now expands through the turbine stages, creating mechanical torque to drive the gas turbine’s compressor and the net torque drives the generator producing electrical power.
The challenge faced by all gas turbines is that as ambient temperature or elevation rises, the density of the air naturally decreases, reducing the mass flow into the gas turbine. This reduced mass flow results in reducing the fuel flow proportionately to hold turbine inlet temperatures constant. This results in lower output.
Turbophase restores the mass flow that is naturally missing by injecting air into the compressor discharge. The gas turbine control system reacts naturally and adds a proportionate amount of fuel to account for the increase air mass flow, resulting in constant combustion and turbine inlet temperatures. The increased mass flow through the turbine section increases the mechanical torque to the compressor and generator.
How Turbophase Modules are Installed at a Power Plant
A Turbophase system can have several modules and each module produces a certain mass flow of pressurized hot air. Each module is factory acceptance tested to ensure quality including correct air pressure and temperature prior to shipment to the power plant site. Depending on the size of the gas turbine, and the requirements of the power plant, a Turbophase system may have 1 module or more than 10 modules. Each module is approximately 32 feet long by 8 feet wide by 18 feet tall at its highest point. A typical Turbophase installation requires no unplanned outage at the plant.
A concrete foundation is poured for each module and a stainless steel air header pipe connects all the modules together and then a single pipe with expansion loops connects the Turbophase system to the gas turbine through the inlet bleed heat pipe or another similar tie in point in order to ultimately have the air arrive at the combustion wrapper. A Turbophase installation can be sited up to 1 kilometer from the gas turbine with minimal pressure loss, which is accounted for when the Turbophase air is produced. In addition to foundation and pipe, the Turbophase modules require a fuel supply from the plant of either natural gas or diesel.
In the case of a water-cooled system, a supply of water from the plant. No water is consumed, all is returned to the plant.
In the event the plant has no water available, the Turbophase system is cooled with a fin-fan cooler which are installed above each Turbophase module, not impacting the footprint of the system.
The Turbophase system is controlled by on board Turbophase controllers for each module and then a system integration to the plant with the Turbophase master controller (TPMC) and remote HMIs in the plant control room.
The auxiliary power load is small, ranging from 35kw for the Water cooled to 135 kW for the air cooler. The Turbophase system also includes a local Turbophase electronics enclosure, which comes pre-assembled in a 20-foot shipping container and houses the local power distribution and Turbophase master controller(TPMC).