Cyclone Waste Heat Engine
The Cyclone Waste Heat Engine (WHE) is a small steam engine developed to produce power from steam created from waste heat. It is an offshoot of the development of the Cyclone Mark V Engine by the company Cyclone Power Technologies of Pampano Beach, Florida. The original versions were designed by inventor Harry Schoell, founder of Cyclone Power Technologies and the later versions have been designed by the Ohio State University Center for Automotive Research (OSU-CAR).
In July 2014, Cyclone Power Technologies separated its waste heat engine product into the separate WHE Generation Corporation,[1] which does business under the trade name Q2Power, Inc., of Lancaster, Ohio.
Engine construction and operation
The Cyclone Waste Heat Engine (WHE) is a single-acting, Uniflow steam engine. The two main variations are the WHE-25, a six-cylinder radial engine that was under development until November 2013, and the WHE-DR that has been under development since.[2] The known specifications of these engines are:
Specifications
| Quantity | WHE-25[3] | WHE-DR |
|---|---|---|
| Cylinders | 6 | 3 |
| Bore | 1.870 inch (47.5 mm) | slightly larger[2] |
| Stroke | 1.5 inch (38.1 mm) | ? |
| Displacement | 24.78cu in (406 cc) | ? |
| Operating RPM | 50 to 3000 | unknown, but presumably a little above 1800 to power an asynchonous generator |
| Operating Pressure | 25 to 200 psi (~1.7 to 14 bar) | ? |
| Maximum Power Output | 15.8 hp (11.8 kW) at 3000 rpm with 200 psi 600 °F (14 bar 315 °C) steam | 22 hp (16.4 kW), operating conditions unknown[4] |
| Admission Valve | Poppet valve in each head actuated by a pushrod from a cam on the crankshaft | Central rotary valve on top of crankshaft with steam lines to each cylinder head[5] |
| Exhaust Valve | Reed valve in piston top, actuated by connecting rod | Ball valve in piston top, actuated by connecting rod[6] |
A display model of a 12-cylinder radial engine was built,[7] but it is not known if any working engines were built in this configuration.
A video of the "WHE-252" updated version of the WHE-25 was posted on March 12, 2013.[8] It is claimed to be capable of producing 10 hp.
Operation
The timing on the admission valve(s) is arranged so that no matter what position the engine is in when it stopped last, the valve to at least one cylinder will always be open. This allows the engine to start by itself whenever steam is supplied to it, without other means such as an electric starter motor to cause the engine to initially rotate.
The fraction of the stroke in which the admission valve is open on a steam engine is termed the cutoff. On the WHE-25 it is 34% of the stroke.[3] From top dead center to 34% of stroke, the crank turns through an angle of about 71°. In the six cylinder engine, one piston reaches top dead center every 360°/6 = 60°. The three cylinder WHE-DR engine only has a piston reach TDC every 120°, so its admission valve must be open over a much larger angle to ensure the engine is self-starting. If the valve is open for 130° of crankshaft rotation, the cutoff value would be about 64%.
The expansion stroke of the steam engine covers piston travel from top dead center to bottom dead center. When the piston reverses to return to top dead center, an exhaust valve needs to open so that the expanded steam from the previous stroke can be released from the cylinder. The WHE engine has an exhaust valve in each piston actuated by a protrusion on the connecting rod (see figure to right). On the exhaust stroke the angle of the connecting rod causes it to open the piston valve, allowing expanded steam to exhaust into the crankcase.
The WHE-25 design used a reed valve, which is a piece of thin metal covering the top of the piston (as shown in the figure). The WHE-DR design replaced the reed with a ball resting in a valve seat in the piston crown.[6]
'Spider bearing'
The WHE-25 is designed with six connecting rods sharing one crankpin on the crankshaft. The standard design for such connection is with a master connecting rod connected to one piston and the remaining rods connected to pins in the big end of the master rod. Harry Schoell, inventor of the WHE, also invented what he called a 'spider bearing',[9] which is a disk that can rotate around the crankpin, and has one bearing journal around its periphery for each of the six connecting rods. While this design eliminates the need for a separate master rod, it introduces one uncontrolled degree of freedom, i.e., the spider bearing itself can rotate in one direction until its motion is stopped by impacting with the connecting rods, then rotate in the other direction through some angle before it is stopped by again impacting connecting rods.
The WHE-DR design eliminated the spider bearing by having each cylinder offset from the others longitudinally so that the connecting rod big ends can fit on a shared crankpin side by side. It has been reported that "Initial testing has demonstrated significantly smoother and quieter operation."[2] Elimination of the spider bearing was the only design change that would have led to this improvement.
Water lubrication
The Waste Heat Engine's design requires the use of water to lubricate the moving parts because exhaust steam goes into the engine crankcase. Any oil used to lubricate crankshaft and connecting rod bearings would soon form an emulsion of oil and water that would have very poor lubricating properties.
Journal bearings on the crankshaft and connecting rods and the pistons sliding in their cylinders operate in the hydrodynamic lubrication regime. The carrying capacity of a journal bearing is a direct function of the dynamic viscosity of the lubricating fluid. Water at 20 °C has a viscosity of 0.001002 Pa·s, while a typical motor oil could have a viscosity of about 0.250 Pa·s.[10] Thus, water is about 250 times less effective of a lubricant than oil.
Cyclone Power Technologies had contracted with the Ohio State University Center for Automotive Research (OSU-CAR) for engineering analysis. A March 8, 2014 presentation[6] by OSU-CAR described the engine bearings as a "critical path issue" and stated:
- "Little or no data exists outside Cyclone’s own experience for the use of water lubrication for either ball bearings or roller bearings in our environment and under our loadings. Calculated life using just the bearing load and the scaling factors for the viscosity of the lubricant indicate that very high ratio of load capacity to applied load is required."
- "Minimal data exists for the use of water lubricated polymer journal bearings in our environment and under our loadings. Factors of a 4:1 increase in life have been shown with submerged operation, but little long term wear data is available with pressurized water lubrication."
The contract between Cyclone Power Technologies and Phoenix Power Group for the WHE[11] states that Phoenix Power Group will make a $150,000 progress payment "Upon the completion of 200 hours of durability testing of WHE version 5.0 as conducted and/or overseen by OSU. The durability testing shall consist of the WHE engine operating, without failure, and producing 10hp to 20hp". As of March 25, 2015 there has been no indication they have made a water lubricated engine pass this 200-hour endurance test.
Efficiency
No independent tests of any WHE model have been reported, but an indication comes from information published regarding the test waste heat recovery system for Bent Glass Design of Hatboro, PA.[12] The system was described as providing up to 10 kW electrical output using a WHE-25 model engine and "will convert over 500,000 BTUs of exhaust heat from the customer's glass manufacturing furnaces into electric power." A heat flow rate 500,000 BTU/hr equals 146.5 kW.
The WHE-25 engine has a 34% cutoff.[3] This allows for the remaining 66% of the piston stroke to expand the steam, extracting work from it and causing the pressure to drop. The figure to the right shows how pressure in the cylinder of a steam engine drops after the cutoff point. The WHE-DR must have a much later cutoff to allow it to self-start. The later cutoff leads to a larger mean effective pressure that will give a larger power output for an engine of a given size operating at a given speed, but also leads to a decrease in efficiency since steam is at a higher pressure when exhausted from the cylinder and less of its energy has been converted to mechanical work.
Auxiliary equipment
Expander: A steam engine is just one component in a Rankine cycle power system. The figure of the Rankine cycle at the right shows a turbine rather than a reciprocating piston engine between states 3 and 4, but either device acts as the expander stage in the cycle.
Condenser: The device between states 4 and 1 is the condenser. It removes heat from the engine exhaust steam to condense it back into water. In the case of the WHE-25 engine in the previous sub-section, of the 146.5 kW of heat energy supplied in the initial steam, 10 kW was converted into electricity. That leaves 146.5 - 10 = 136.5 kW of heat energy to be removed by the condenser. As a point of comparison, a Caterpillar C13 diesel engine that is commonly used in tractor-trailer trucks has a heat rejection to coolant rating of 128 kW.[13] Thus, a condenser for the WHE-25 engine producing 10 kW of power would be about the size of the radiator on a semi-truck. The newer WHE-DR is likely less efficient, so would need an even bigger condenser for the same output power.
The condenser requires enough airflow to take away the heat. A fan is usually used to create this airflow, and its power consumption reduces the net power available from the system.
Feed water pump: The condensed water is stored in a tank, then pumped to high pressure by the feed water pump, states 1 to 2 in the figure. This pump requires a source of power, as well as a control system so that it pumps the proper amount of water to compensate for the amount of steam put into the engine.
Boiler: Heat is added to the water in the boiler to create the steam, states 2 to 3 in the figure. Boilers are sometimes called steam generators, and Cyclone Power Technologies has used the term "Combustion Chamber/Heat Exchanger" or "CCHX".[14] Regardless of the name used, if the system pressure is greater than 15 psi (1 bar) and heat is added, the device is legally a boiler. All states in the United States except Idaho and Wyoming and all provinces in Canada have legally adopted the requirement for boilers to be registered with the National Board of Boiler and Pressure Vessel Inspectors.[15] Registration includes the requirements that the boiler's design be approved as meeting the ASME Boiler and Pressure Vessel Code (BPVC), must be constructed in a facility currently authorized by ASME to construct such boilers, must be installed and tested to the approval of a National Board inspector, and, is required to undergo periodic inspections at the owner's expense.
The jurisdiction may also require the installation be operated by a licensed stationary engineer, as well as be covered by sufficient liability insurance.
The reason for such scrutiny is because of the catastrophic losses that can occur due to a boiler explosion.
A system will also require an approved steam safety valve and water level control as well as valves for water into the boiler and steam to the engine. If the system is intended to run without supervision, then sensors and automatic safety shutdown systems are needed.
Thus, the waste heat engine may be one of the least expensive components of a complete waste heat recovery system.
Timeline
| Date | Event |
|---|---|
| Sept 24, 2007 |
Cyclone Power Technologies announced the Waste Heat Engine (WHE)"[16] as "a self-starting engine that operates in a low pressure, low temperature range." Specifications were not given. |
| September 23, 2008 |
Cyclone Power Technologies was "currently testing the prototype WHE Solar System, which it hopes to introduce to consumers in the first half of 2009", with it having a six-cylinder, 10 kW engine.[17] |
| November 17, 2008 |
Bent Glass Design of Hatboro, PA purchases a Waste Heat Engine (WHE) cogeneration system from Cyclone Power Technologies.[12] It is claimed the system "will convert over 500,000 BTUs of exhaust heat from the customer's glass manufacturing furnaces into electric power." |
| Jan 28, 2009 |
An order is placed for a WHE-based biomass-fueled system by Robotic Technology Inc. of Maryland, who were developing the EATR, a robotic vehicle to be powered by foraged vegetation.[12] "Cyclone will build and deliver within six months the engine with a biomass combustion chamber for demonstration purposes." |
| April 22, 2009 |
Waste Heat Resources LLC of Londonderry, NH receives license to sell the Cyclone WHE as part of their combined heat and power system, "the WHR Energy Forge."[18] |
| July 22, 2009 |
A durability test is announced: "Over the next month, Cyclone will run its WHE for a minimum of several hundred hours under the load of an electric alternator. The company then plans to break-down the engine to study the effects of long term operation on parts and components prior to installation at its initial beta site. [19] No results from the test are disclosed. |
| December 11, 2009 |
Great Wall Alternative Power Systems Ltd. of China is licensed to produce WHE engines for the Chinese market.[20] |
| March 2010 |
Waste Heat Resources LLC license is terminated.[21] No systems using the WHE are known to have been built. |
| March 30, 2010 |
Delivery of the biomass-to-power engine system to Robotic Technologies, Inc.[22] Robotic Technologies' research contract with DARPA was not renewed, and it does not appear the system was run after being delivered. |
| July 2010 |
Delivery of the WHE-25 system to Bent Glass Design for installation.[23] |
| December 14, 2010 |
The WHE system at Bent Glass Designs is reported to be operating and feeding electrical power into the grid.[24] "We plan to conduct extensive thermal and operational testing, data acquisition and system configuration over the next few months, while we analyze its performance in real world environments." This is the last mention of the Bent Glass Design project by Cyclone. No information on system operation or performance is released. |
| December 21, 2010 |
Cyclone Power Technologies, Phoenix Power Group and Clean Burn Inc. announce they "intend on launching several dozen pilot programs in the first half of 2011 for the 10kW waste oil power generator called the Phoenix-10, and the small-scale industrial waste heat recovery unit called the WHE-GEN-10. Broader commercial sales of these units are anticipated to commence later in the year."[25] |
| March 1, 2011 |
Agreement between Cyclone Power Technologies and TopLine Energy Systems LLC of Florida to engineer and provide "parts for 12 completed engines within 60 days".[26] |
| April 13, 2012 |
Cyclone reports "the first 4 engines have been produced, and testing has commenced at Cyclone’s facility"[27] of the engines described in the March 1, 2011 agreement with TopLine Energy Systems. This was the last time interaction between Cyclone and TopLine was mentioned. There was no information given about the remaining 8 contracted engines, or the features or performance of the TopLine-engineered engines. |
| September, 2012 |
Cyclone and Phoenix Power Group "passed a major technological hurdle in the development of a 7kW waste oil power co-generator when the parties successfully integrated Phoenix’s waste oil combustion chamber / heat exchanger (CCHX) with Cyclone’s WHE-25 system."[28] |
| February 2013 | Cyclone "signed an agreement with The Ohio State University’s Center for Automotive Research (OSU-CAR) to assist in the commercialization of its external combustion engine technology."[29] |
| September 2013 |
Great Wall Alternative Power Systems terminates WHE engine license agreement with Cyclone Power Technologies.[30] No engines were known to be built under the agreement. |
| November 5, 2013 | The WHE-DR engine, designed and built by OSU-CAR, is announced.[31] It is substantially different from the Harry Schoell designed WHE-25. |
| July 17, 2014 | Cyclone Power Technologies separates WHE Generation Corp into an independent company. "Christopher Nelson resigned as President of Cyclone to assume the position of Chief Executive Officer of WHE GEN."[1] |
| January 14, 2016 | Q2Power, the new name of WHE Generation Corp, announces an agreement with Phoenix Power Corp predicting engine production and delivery to customers "early in 2016."[32] |
References
- 1 2 Quarterly Report for the quarterly period ended June 30, 2014, filed with the Securities and Exchange Commission. Retrieved from http://www.sec.gov/Archives/edgar/data/1442711/000139843214000332/cypw20140630_10q.htm
- 1 2 3 Press release "Cyclone Power Technologies completes build of next generation waste heat engine with The Ohio State University's Center for Automotive Research", November 5, 2013. Retrieved from http://car.osu.edu/news/cyclone-power-technologies-completes-build-next-generation-waste-heat-engine-ohio-state
- 1 2 3 Cyclone Waste Heat Engine Specification Sheet. Retrieved from http://www.cyclonepower.com/PDF/WHE_Spec_Sheet.pdf
- ↑ Press release "Cyclone’s Waste-to-Power Subsidiary Receives Initial $1,000,000 Purchase Order for Waste Heat Engines from Phoenix Power Group", April 22, 2014. Retrieved from http://ih.advfn.com/p.php?pid=nmona&article=61913778
- ↑ Photograph of disassembled WHE-DR engine. Retrieved from https://scontent-lga.xx.fbcdn.net/hphotos-xfp1/t31.0-8/1966188_732848463413888_658179558_o.jpg
- 1 2 3 ENGINEERING ANALYSIS OF CYCLONE POWER TECHNOLOGIES’ WASTE HEAT ENGINE. Retrieved from http://www.cyclonepower.com/2014/IAASP_Presentation_OSU-CAR_Cyclone_March-8-2014.pdf
- ↑ Curtis Ellzey interviews Harry Schoell about Waste Heat Engine. Retrieved from http://www.engineeringtv.com/video/Cyclone-Waste-Heat-Engine
- ↑ Youtube video of updated model WHE-252 Waste Heat Engine, March 12, 2013. Retrieved from https://www.youtube.com/watch?v=ah9JGQ6vEXk
- ↑ US Patent 7900454, "Connecting rod journals and crankshaft spider bearing in an engine". Retrieved from http://www.google.com/patents/US7900454
- ↑ Serway, Raymond A. (1996). Physics for Scientists & Engineers (4th ed.). Saunders College Publishing. ISBN 0-03-005932-1.
- ↑ Amended and Restated Systems Application License Agreement, September 30, 2013, filed as Exhibit 10.25 with the Securities and Exchange Commission. Retrieved from http://www.sec.gov/Archives/edgar/data/1442711/000139843213000687/ex10-25.htm
- 1 2 3 Press release "Bent Glass Design Purchases Engine System From Cyclone Power Technologies" Retrieved from http://www.marketwired.com/press-release/Bent-Glass-Design-Purchases-Engine-System-From-Cyclone-Power-Technologies-921147.htm
- ↑ Caterpillar C13 diesel engine generator set specification sheet. Retrieved from http://pdf.cat.com/cda/files/4412670/7/lehe0439-00.pdf
- ↑ Press release "Cyclone Power Technologies and Phoenix Power Group Successfully Integrate Waste Oil Co-Generation System". Retrieved from http://www.marketwired.com/press-release/cyclone-power-technologies-phoenix-power-group-successfully-integrate-waste-oil-co-generation-otcqb-cypw-1706457.htm
- ↑ National Board Synopsis Map 2015. Retrieved from http://www.nationalboard.org/SiteDocuments/Synopsis/2015_map.pdf
- ↑ Press release "Cyclone Power Technologies Files Patent Application For New, Eco-Friendly Waste Heat Engine Technology" Retrieved from http://www.marketwired.com/press-release/cyclone-power-technologies-files-patent-application-new-eco-friendly-waste-heat-engine-772705.htm
- ↑ Press release "Federal Solar Investment Tax Credits to Benefit Cyclone's Revolutionary Waste Heat Engine" Retrieved from http://www.marketwired.com/press-release/federal-solar-investment-tax-credits-benefit-cyclones-revolutionary-waste-heat-engine-902724.htm
- ↑ Press release "Cyclone Power Technologies Secures License for Waste Heat Recovery Power Systems", Retrieved from http://www.businesswire.com/news/home/20090422005428/en/Cyclone-Power-Technologies-Secures-License-Waste-Heat#.VQ2ed-F26zk
- ↑ Press release "Cyclone Power Commences Durability Testing of Waste Heat Engine", July 22, 2009. Retrieved from http://www.bloomberg.com/apps/news?pid=newsarchive&sid=ayEemLBc7gGA
- ↑ Technology License Agreement, filed as Exhibit 10.9 with the Securities and Exchange Commission. Retrieved from https://www.sec.gov/Archives/edgar/data/1442711/000139843211000685/ex10-9.htm
- ↑ Letter to Shareholders for Annual Report for the year ended December 31, 2009, filed with OTC Markets Group. Retrieved from http://www.otcmarkets.com/financialReportViewer?symbol=CYPW&id=30574
- ↑ Quarterly Report for the quarterly period ended March 31, 2010, filed with OTC Markets Group. Retrieved from http://www.otcmarkets.com/financialReportViewer?symbol=CYPW&id=31974
- ↑ Quarterly Report for the quarterly period ended September 30, 2010, filed with OTC Markets Group. Retrieved from http://www.otcmarkets.com/financialReportViewer?symbol=CYPW&id=39092
- ↑ Press release "Cyclone Power Technologies Successfully Powers-Up Small-Scale Waste Heat Recovery Pilot". Retrieved from http://www.businesswire.com/news/home/20101214005528/en/Cyclone-Power-Technologies-Successfully-Powers-Up%C2%A0Small-Scale-Waste-Heat#.VRDUUeF26zk
- ↑ Press release "Cyclone Power Technologies and Its Partners Generate Strong Product Interest at Power-Gen International", December 21, 2010. Retrieved from http://www.bloomberg.com/apps/news?pid=newsarchive&sid=aY1kRsgiR6oc
- ↑ Letter of Understanding with TopLine Energy Systems, filed as Exhibit EXHIBIT 10.13 with the Securities and Exchange Commission. Retrieved from http://www.sec.gov/Archives/edgar/data/1442711/000139843211000847/ex10-13.htm
- ↑ Pages 3-4 in the Annual Report for the year ended December 31, 2011, filed with the Securities and Exchange Commission. Retrieved from http://www.sec.gov/Archives/edgar/data/1442711/000139843212000320/cyclone_10k-123111.htm
- ↑ Quarterly Report for the quarterly period ended September 30, 2012, filed with the Securities and Exchange Commission. Retrieved from http://www.sec.gov/Archives/edgar/data/1442711/000139843212000856/cypw_10q-093012.htm
- ↑ Quarterly Report for the quarterly period ended March 30, 2013, filed with the Securities and Exchange Commission. Retrieved from http://www.sec.gov/Archives/edgar/data/1442711/000143774913006106/cypw_10q-033113.htm
- ↑ Page 19 in the Quarterly Report for the quarterly period ended September 30, 2013, filed with the Securities and Exchange Commission. Retrieved from https://www.sec.gov/Archives/edgar/data/1442711/000139843213000757/cypw20130930_10q.htm
- ↑ Press release "Cyclone Completes Build of Next Generation Waste Heat Engine With The Ohio State University’s Center for Automotive Research". Retrieved from http://finance.yahoo.com/news/cyclone-completes-build-next-generation-130000569.html
- ↑ Press Release "Q2Power Signs Collaboration Agreement With Phoenix Power to Streamline Sales Process, Open New Markets for Q2Power Products", January 14, 2016. Retrieved from http://money.cnn.com/news/newsfeeds/articles/marketwire/1238941.htm
