直接式污水源热泵的污垢及对系统流动换热的影响

Urban sewage contains a wealth of low heat energy, which can be directly used as heat and cold source of heat pump for buildings heating and air conditioning, and thus the sewage has a huge development potentials and utilization of value. However, the quality of urban sewage is so poor that its thermal and flow performance are very different from the clean water. Fouling inside the heat exchanger of the unit will increase its flow resistance, reduce the heat transfer coefficient, and aggravate corrosive characteristics. These problems also causes the two heat exchanger do not match and the unit overall performance degradation. Researching on the heat pump system where the sewage flows directly into the unit, namely the direct system, This project is devoted to explore in depths the above issues using the following methods: experimental determination of the composition of the fouling inside the unit heat exchanger, study the scaling mechanism and propose anti-fouling countermeasures; experimental summary the characteristics and laws of the sewage flow, heat exchangers and fouling resistance; establishing a system simulation platform to study the heat transfer characteristics of sewage evaporator, condenser and two heat exchangers reasonable match and performance analysis of the direct-heat pump system. Sewage source heat pump technology is an interdisciplinary research at the forefront of the current HVAC field, with prominent development prospects. This project seeks to make a breakthrough in both technological research and engineering practice and to provide reference for the areas such as the other unclear water source heat pump system, air-conditioning cooling system and the industrial waste water recycling system.

城市污水中蕴含有丰富的低位热能，将其直接作为热泵的冷热源为建筑供暖空调将具有巨大的开发利用价值。城市污水的水质极其恶劣，其热工与流动性能与清水有很大的不同。机组换热器内的污垢会造成其流动阻力加大、换热系数降低、腐蚀性增强，同时还会造成机组两换热器的换热量不匹配，机组整体性能下降等问题。研发污水直接进机组的热泵系统，即直接式系统，本项目拟采用以下方法对上述问题展开深入研究：实验测定机组换热器内污垢的成分，研究其结垢机理，提出防垢除垢对策；理论与实验总结污水的流动、换热以及污垢热阻的特性与规律；搭建系统模拟平台，研究污水蒸发器、冷凝器的换热特性及其直接式热泵系统两换热器的合理匹配与性能分析。污水源热泵技术是当前暖通空调领域的交叉性前沿课题，具有强大发展生命力，本项目力争在技术研究和工程实践上都取得突破性进展，为其他非清洁水源热泵系统、空调冷却水系统、工业废水的回收利用等领域的研发提供参考和借鉴

城市污水中大量低位热能的开发利用，对建筑供暖空调将具有巨大的节能潜力，但因为城市污水水质极差，流动换热特性与清水差距很大，污垢也会造成换热器内流动阻力增大，换热系数降低，堵塞及腐蚀的可能性增强，机组两换热器的换热量不匹配，整体性能下降的问题，本项目理论与实验相结合，总结污水的流动、换热及污垢热阻的计算式；搭建了系统模拟平台，研究了污水换热器的换热特性及匹配特性，分析了直接式污水源热泵机组的性能。为污水源热泵系统的工程推广应用提供理论基础及技术支持。