ABSTRACT
The present paper describes a heat recovery technology based on phase change materials (PCMs) aimed at the reuse of the diesel engine heat wasted in the ambient. There were developed several compact PCM-based heat storage devices for the capture and recovery of excess heat from various sources (exhaust gas and coolant liquid) facilitating engine start at low ambient temperature. Ba(OH)2.8H2O (TPHASE CHANGE=351 K), KNO3-LiNO3 (TPHASE CHANGE=406 K) or NaCH3-COO.3H2O (TPHASE CHANGE=331 K) were tested as PCMs. There was carried out a series of laboratory and field on-board tests on a city bus LiAZ-5256 equipped with a KamAZ-7408.10 diesel engine. The experiments have proven the efficiency and reliability of the proposed technology. Moreover, there was developed a system combining a catalytic converter and a phase-change heat storage device (CC-PCHSD) aimed at the improving the catalyst efficiency operating in a transient mode in urban conditions. Such a device allows to store the heat of exhaust gas from the vehicle diesel engine running at full load and to return it to the catalyst while the engine is operating at low load. The results of numerical investigations showed that the use of a NaOH-based PCHSD (TPHASE CHANGE=572 K) may increase the catalyst efficiency from 4 to 74 % for hydrocarbons and from 10 to 86 % for carbon monoxide by maintaining its working temperature. The paper is dedicated to the memory of professor Valentin Shulgin.
