Abstract:
In the traditional distributed energy system, vaporizing water needs to consume a large amount of waste heat of mid and high-temperature flue gas, which reduces the refrigeration potential of the system, and a large amount of waste heat of medium and high temperature flue gas is depreciated to the low temperature latent heat of water. Therefore, a novel chemical reinjection biogas distributed energy supply system is proposed in this paper. Part of the flue gas is returned to the reformer to provide oxidizer (O
2, H
2O and CO
2) and heat for the methane reforming reaction, and the methane tri-reforming reaction occurs, and the heat of the other part of the flue gas is effectively recovered by reheating the air. Under the design working condition, the new system achieves an increase of 122.40 kW (13.17%) in electricity generation and 538.85 kW (160.52%) in cooling capacity. Additionally, the exergy efficiency of the new system is increased by 16.90%. The chemical recuperation system has a better advantage in keeping heat for biogas digester. The lowest ambient temperature that the new system and the chemical regenerative system can meet is 9.90 and 7.44℃, respectively. When the ambient temperature is 7.44℃, the exergy efficiency of the new system is still increased by 7.40% compared with that of the chemical regenerative system. This research can provide a new technical scheme for the application of biogas in the field of distributed energy supply.