Description: Das Projekt "Kuehlung und Fahrzeugklimasysteme unter Umweltgesichtspunkten" wird vom Umweltbundesamt gefördert und von Bayerische Motorenwerke AG durchgeführt. General Information: The proposed research is directed at developing a refrigeration cycle for use in automotive air conditioning systems. The new cycle will use a naturally occurring gas as a refrigerant. Because of the new refrigerants properties and the common working conditions of an automotive a/c cycle it will be necessary to develop a completely new transcritical vapour compression system. Major tasks are: (I) Calculation of thermodynamic cycle and of components based on typical car specifications; (II) Development of components - compressor, heat exchangers, expansion device, control device, receiver and hoses; (III) Bench tests; (IV) Construction of prototypes; (V) Car tests in windtunnel and in-field; (VI) Safety and Acoustics evaluation. Successful completion will provide a long-term solution for an environmentally harmless refrigeration system. Achievements: A completely new refrigeration cycle for air-conditioning with carbon dioxide technology was developed. The main emphasis was placed on the thermodynamic calculation of the cycle and the components according to a revised specification, the development of the components such as compressor, heat exchangers, means for control and expansion, storage vessels and refrigerant hoses, test bench investigations, construction of two vehicles, vehicle tests in wind tunnels and road tests and the evaluation of safety and costs aspects. Following this, a direct comparison to a current serial air-conditioning system under commonly acknowledged conditions became possible. An automotive air-conditioning system is often operated above the critical temperature of CO(2) at 31.1 Degree of Celsius. Therefore a CO(2) system will mostly work in a transcritical cycle mostly. At supercritical conditions (critical pressure: 73.8 bar), pressure and temperature are independent of each other. The conditions in the evaporator remain subcritical. In this transcritical cycle the refrigeration capacity, the compressor work and thereby the cycle efficiency depend on the existing discharge pressure in accordance with the heat rejection temperature. The optimum discharge pressure is a function of the ambient temperature. The refrigeration circuit control should provide sufficient cooling capacity at high efficiency with satisfying passenger comfort, largely independent from the momentary driving and climate conditions. The vehicle refrigeration circuit consists of a compressor, gas cooler, expansion device, evaporator, accumulator and internal heat exchanger. The packaging shows only slight differences to series vehicles. The small cross-section of the refrigerant pipes makes it easier to find a route through the tight engine compartment. The refrigeration cycle with CO(2) operates at high pressure levels, but this does not represent an significantly increased risk with adapted components. Due to refrigerant properties the new developed components remain nearly comparable in respect of weight and dimensions.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Fahrzeugklimaanlage ? Klimaanlage ? Straßentunnel ? Wärmeeinleitung ? Kühlfahrzeug ? Akkumulator ? Akustik ? Kältemittel ? Kühlverfahren ? Personenkraftwagen ? Thermodynamik ? Wind ? Fahrzeugindustrie ? Main ? Arbeitsstoff ? Automobil ? Fahrzeugbau ? Gemeineigentum ? Kohlendioxid ? Kostenrechnung ? Kühlmittel ? Messtechnik ? Umweltschutzmaßnahme ? Wärmeübertrager ? Wärmespeicher ? Gasförmiger Stoff ? Wärmeeffizienz ? Kühlsystem ? Kühlung ? Sicherheitstechnik ? Strömungsmechanik ? Vergleichsanalyse ? Automobilindustrie ? Fahrzeugtechnik ? Wärmekapazität ? Werkstoffkunde ? Laborversuch ? Kontrollsystem ? Kostenanalyse ? Straßenverkehrssicherheit ? Kreislaufsystem ? Brüdenkompression ? Risiko ? Rohrleitung ? Sicherheitsvorschrift ? Umweltfreundliche Technologie ? Neuartige Materialien ? Physikalische Größe ? Anlagenbau ? Anlagenbemessung ? Substitutionseffekt ? Verdichter ? Versuchsfahrzeug ? Windkanal ? aerospace technology ? industrial manufacture ? Gasentspannungsmaschine ? Prototyp ? Akustische Kenngröße ?
Region: Bayern
Bounding box: 12.53381° .. 12.53381° x 47.795° .. 47.795°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1994-06-01 - 1997-05-31
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