A novel defrosting method in gasoline vapor recovery application

Abstract

Condensation method is comprehensively applied for gasoline vapor recovery (GVR), of which frosts in the heat exchanger is the greatest challenge, especially for the continuous long running cases. A novel dual channel GVR cascade refrigeration system with shell-tube heat exchanger was presented and tested in this paper. With onework-one-standby evaporator settings, combined with refrigerant evacuation and delay switching strategies, the defrosting of low temperature shell-tube heat exchanger was analyzed and solved. Also multi-stage cycle was introduced to supply three cooling stage, which cooled the gasoline vapor from ordinary temperature to about -70°C. By the means of industrial application validation and process calculation, the ability of the non-stop cooling during defrosting was verified. The refrigerant evacuation was proposed to prevent high pressure drop caused by frost accumulation, which also improved the cooling capacity by 28.2% and approached the defrost efficiency of 55.4%. In addition, it was found that delay switching can effectively reduce the capacity fluctuation. Based on sensitivity studies, 20 minutes delay was identified as the best switching timing for this device. The capacity of this system performed lower reduction, higher duty ratio and defrost efficiency.

Improving the economic efficiency of vapor recovery units at hydrocarbon loading terminals

“…Analyzing the work related to the protection of the environment from VOCs at terminals, we note that there is a concept of considering this topic from the point of view of increasing technological efficiency and monitoring the work of the VRU (Gruber, 2019;Helmig et al, 2014;Karbasian et al, 2017;Klimont et al, 2000;Korshak et al 2019;Krummenauer et al, 2018;Liang et al, 2018;Pannucharoenwong et al, 2018;Rudd and Hill, 2001;Seo et al, 2000;Shibuya, 2014;Shipley, 2011). Nevertheless, even with the development of such measures, the prevalence of VRU at terminals in many emerging economies remains low (Tcvetkov et al, 2020).…”

Machine learning approach to improve vapor recovery: Prediction and frequency converter with a new vapor recovery system

“…Several methods have been applied to the GV recovery, such as adsorption, [10][11][12] membrane separation, [13][14][15][16] condensation, 17,18 and a combination of adsorption and absorption methods. 19 Chue et al 11 developed a pressure swing adsorption (PSA) unit, and approximately 21-48 liters of gasoline per hour was recovered.…”

“…Several methods have been applied to the GV recovery, such as adsorption, 10–12 membrane separation, 13–16 condensation, 17,18 and a combination of adsorption and absorption methods. 19 Chue et al.…”

Scientific and technological progress and future perspectives of the solar assisted heat pump (SAHP) system

“…Fig. 17 Defrost process: (a) Using stored solar energy to defrost [79]; (b) Using recovery heat in gasoline vapour[80] …”