{
    "title": "Dexpressor - Revolutionary new engine technology converts waste heat to rotary work; reduces load 50%",
    "inventor_name": "Tony Dye",
    "publication_year": 2007,
    "device_name": "Dexpressor",
    "goal": "Reduce CO_2 emissions by up to 50 % by harvesting waste-heat from the exhaust and converting it into additional mechanical power for the engine.",
    "problem_addressed": "Only ~20 % of the energy from fossil-fuel combustion is used for work; the remaining ~30 % is lost as low-grade waste heat, leading to higher fuel consumption and CO_2 emissions.",
    "concept_summary": "The Dexpressor captures exhaust-gas heat, transfers it to water in a heat-exchange coil around the exhaust manifold, raises the water to super-critical conditions (~370  deg C, 1000 bar), and uses the resulting high-pressure fluid to drive a pair of low-friction rotors. One rotor feeds torque to the engine crankshaft, effectively adding power and allowing a smaller engine size for the same output, thereby cutting fuel use and CO_2 emissions.",
    "detailed_description": "A closed-loop system extracts low-grade heat from the exhaust, circulates water through a coil that becomes super-critical, and stores the pressure in a retention chamber. Two rotors, driven by the high-pressure fluid, convert this pressure into mechanical rotation. One rotor is mechanically linked to the engine crankshaft, providing additional torque. The system is intended to be compact enough for automotive integration and could also be applied to stationary power-plant engines.",
    "category": "Thermal Systems",
    "principles": [
        "heat exchange",
        "supercritical water generation",
        "pressure retention",
        "rotary expansion",
        "thermodynamic cycle"
    ],
    "scientific_domains": [
        "Thermodynamics",
        "Heat Transfer",
        "Mechanical Engineering"
    ],
    "mechanisms_of_action": [
        "collection of exhaust heat",
        "heating water in a coil",
        "creation of super-critical water at high pressure",
        "driving rotors via high-pressure fluid",
        "supplying additional torque to the engine crankshaft"
    ],
    "materials": [
        "water",
        "metal heat-exchange coil",
        "exhaust manifold (metal)",
        "rotor components (metal alloys)",
        "high-strength pressure vessel"
    ],
    "energy_sources": [
        "waste heat from engine exhaust"
    ],
    "inputs": [
        "exhaust heat",
        "water"
    ],
    "outputs": [
        "mechanical torque",
        "reduced fuel consumption",
        "lower CO_2 emissions"
    ],
    "claimed_performance": "Up to 50 % reduction in CO_2 emissions; engine capacity may be reduced by up to 50 % while maintaining performance.",
    "experimental_evidence": "The technology is currently a computer model; a working prototype is planned but not yet built. No quantitative experimental data are presented.",
    "replication_status": null,
    "keywords": [
        "waste heat recovery",
        "supercritical water",
        "rotary expander",
        "engine efficiency",
        "CO_2 reduction",
        "turbocharger alternative"
    ],
    "related_technologies": [
        "turbocharger",
        "exhaust heat recovery systems",
        "supercritical water turbines"
    ],
    "controversy_level": "low",
    "confidence_score": 0.8,
    "practicability_score": 0.5,
    "fringe_score": 0.2,
    "evidence_strength": 0.2,
    "risk_score": 0.1,
    "trl_estimate": 3,
    "source_urls": [
        "http://www.businessweekly.co.uk/news/view_article.asp?article_id=11600",
        "https://rexresearch.com",
        "WO2006000797",
        "EP1753945",
        "EP1751398"
    ],
    "organizations": [
        "Epicam Ltd"
    ],
    "applications": [
        "automotive internal-combustion engines",
        "stationary power-plant engines",
        "any heat-generating engine system"
    ],
    "limitations": [
        "Only a computer model exists; no prototype data",
        "Requires high-pressure supercritical water system",
        "Integration with existing engine designs not demonstrated",
        "Potential material and sealing challenges at 1000 bar"
    ],
    "open_questions": [
        "Actual efficiency of heat-to-mechanical conversion",
        "Durability and wear of high-pressure rotors",
        "Cost and complexity of manufacturing the pressure retention system",
        "Impact on overall engine reliability and maintenance"
    ],
    "red_flags": [
        "No experimental validation presented",
        "Performance claims based solely on modeling",
        "Potential overstating of CO_2 reduction without real-world testing"
    ],
    "evidence_quotes": [
        "Epicam believes its dexpressor, which harvests this wasted heat, could improve the efficiency of the engine, thus decreasing the amount of CO2 released into the atmosphere by up to 50 per cent.",
        "The water in this system is super-heated to around 370 degC, past the stage of steam, becoming super-critical water and building up 1000 bar of pressure.",
        "The pressure is used to turn two rotors, via an innovative pressure retention system, a pair of low friction rotating devices.",
        "The GBP40k award will now give Epicam the financial capability to translate its dexpressor idea from a computer model into a working example of the technology, which the firm expects to complete in four to six months.",
        "The technology could also be employed on a powerplant, or any system similar to an automotive engine which generates heat, and runs a driveshaft."
    ]
}