High Efficiency Steam Engines
The Practical Steam Engine offers opportunities to facility managers in a wide variety of applications:
- Food Processing Plants profitably recover waste steam
- Wood Product Facilities – recover furnace and stack gas heat
- Steel Mills – implement commercial Cogenerations
- Landfills – put methane to productive use
Practical Steam Engine – advantages over turbines:
- Cost: steam turbines are expensive and not effective in smaller system
- Steam Flow: Turbines typically not cost effective when steam flow is less than 10,000 lb/hr
- Efficiency: Turbine efficiency decreases when operating below designed flow rate, but the Practical Steam Engine’s efficiency remains relatively constant throughout the turndown range
- Simplicity: The Practical Steam Engine uses customized gasoline engine components familiar, affordable and easily available to mechanics and operators
Combined Heat and Power
If you are considering an application using hot water or steam for heating, the Practical Steam Engine can improve the application’s economics. The addition of the engine to the system allows it to generate valuable electrical power, gaining more benefit from the capital cost of a heating system.
Pressure Reducing Valves
Like District Energy, many industrial facilities produce steam at a higher pressure than many of their consumers need. This steam system inefficiency can be improved by installing the Practical Steam Engine in parallel to the PRV. The steam engine will reduce the pressure to the system setpoint, which is modifiable in the control system. All Practical Steam engines share a common design. The valve system is designed such that the exhaust pressure can be modified through the user interface screen. That way, if pressure changes need to occur over time, the engine can provide the necessary variability of the steam demand.
Many industrial plants have very high temperature exhaust coming off furnaces. If your industrial waste heat is over 700°F, and your exhaust mass flow is greater than 15,000 lb/hr (7,500 ACFM), then you likely have an application for heat recovery. A waste heat boiler would be installed in the exhaust stream (by you or our partner integrators), water will be boiled and pressurized to 200 psig, then delivered to the steam engine. The steam engine will extract the energy from the steam, use it to produce valuable electricity, and then deliver it to a direct-contact condenser. Our systems are fully integrated, complete with condenser, condensate pump, control system, generator, circuit breaker and protective devices.
The Practical Steam Engine can use steam from a wide variety of sources. Existing steam that is wasted, new steam created from wasted heat, or new steam using alternative fuels all gain new uses with the introduction of the Practical Steam Engine.
Synchronous generators, ranging in size from 50 kW to 300 kW, are direct-coupled to the engine shaft for power generation. By offsetting power consumed at the facility, previously wasted energy is now increased profitability.
Low pressure, saturated steam (typically 250 psig or less at the inlet), is expanded within the cylinders of the engine, maximizing the conversion of steam energy to power. Exhaust pressures can range from 25 psig backpressure, to full vacuum.
Steam is admitted through a moisture separator into the inlet header that supplies steam to all cylinders. A proprietary valve system supplies steam into the cylinders based on the demand signal from the generator control system. As steam availability increases, steam flow is increased into the cylinders, increasing power output. As steam availability decreases, steam flow decreases and power output is reduced.
The valve and engine generator system are identical in either backpressure or condensing configurations. The control system allows for variability of engine exhaust, which is field modifiable. This allows commonality of parts, and modification of operating steam conditions without parts replacement.