Performance evaluation of a waste-heat driven adsorption system for automotive air-conditioning: Part I – Modeling and experimental validation

Abstract

Adsorption systems driven by engine waste heat are one of the possible alternatives to the conventional automobile air conditioning in terms of energy savings and environmental issues. Assessment of this issue are carried in a two-part study. In this first part I, theoretical and experimental investigations were performed on a two bed, silica gel adsorption chiller for automotive applications. A prototype adsorption system with a total weight of about 86 kg was developed and tested to driven by low-grade waste heat. The single adsorbent bed consisted of three plate-fin heat exchangers connected in parallel. An improved nonequilibrium lumped parameter model was developed to predict the transient performance of the system. The model is fully dynamic and takes into account the mass transfer resistance and pressure drop for each component of the system. The results showed that the model is able to accurately predict the dynamic performance of the system under different operating conditions and configuration modes with a short calculation time. The tested chiller was able to produce an average cooling capacity of about 2.1 kW with a COP of 0.35 at the rated operating conditions. Heat recovery system results in increasing the COP by 43% and the cooling power by 4%.

Pre‐adsorption of low‐grade waste steam for high‐temperature steam generation by using composite zeolite and long‐term heat storage salt of MgSO 4

“…Nevertheless, advanced cycles such as heat recovery, mass recovery, thermal wave, and cascade cycle are all effective ways to improve the system performance of adsorption heat pump. Heat recovery process starts after the adsorption/desorption switch. Working fluid heated by the adsorber in the adsorption process flows to the other adsorber in the desorption process.…”

Metal Hydride Beds-Phase Change Materials: Dual Mode Thermal Energy Storage for Medium-High Temperature Industrial Waste Heat Recovery

“…Furthermore, thermochemical energy materials allow for long-term energy storages as compared to PCMs, which are prone to thermal losses when stored for a long period. To date, metal hydrides, salts (e.g., metal halides) hydrates and ammoniates are the most utilized thermochemical materials for closed sorption systems driven by waste-heat intended for refrigeration [28][29][30][31][32][33][34], heat pumps and transformer applications [34][35][36][37]. The well-accepted layout of these sorption systems is two tanks interconnected, filled with a high temperature (HT) sorbent in one side, and a low temperature (LT) sorbent in the other side.…”

“…The results showed that cold and heat energy densities were 0.6 MJ·kg −1 and 1.498 MJ·kg −1 , respectively. Verde et al [29] investigated the performance of a prototype of waste-heat driven adsorption system for automotive air conditioning. The adsorption system was made of a two-tank silica gel adsorption chiller.…”

Optimization of thermal design and geometrical parameters of a flat tube-fin adsorbent bed for automobile air-conditioning

“…Different types of heat exchangers are used in adsorbent beds such as plate-finned tubes, and a capillary tube bundle HE [12], a flatplate type HE with fins [13], a serpentine flat-pipe HE, and spiral plate HE [14]. Many researchers have proposed various types of sorption bed designs in order to enhance the heat transfer rate in the adsorbent bed [15][16][17][18][19][20][21][22].…”

“…1 (b). The system description, components, and the working principle of the system, silica gel-water air conditioning adsorption system, has been described in detail in our previous work [22,23]. The system was designed and tested under the framework of the TOPMACS project [30] for automotive air conditioning applications.…”