Hard water scale formation and mitigation at higher temperatures

随着英国逐渐远离化石燃料，电动热泵系统将在家庭和商业设施中提供热水和供暖方面发挥关键作用：这些系统已经广泛应用于没有天然气的地方。热泵依赖于冷凝器中的有效传热，这会受到水中存在的硬度盐引起的污垢层（水垢）的形成的影响。水垢的形成随着水温的增加而增加：下一代热泵系统的目标是在85- 90 ℃下供水，因此需要不需要使用化学剂量的可持续缓解方法。该研究的主要目的是：（i）在热泵运行条件下开发板式换热器中结垢形成的定量模型，以便这些模型可以被设计为最小化污垢层的生长速率;（ii）量化表面处理和水预处理策略对这些较高温度下污垢速率的影响，以及（iii）确定换热器后被动捕获技术的有效性，以防止从热水中分离的污垢或污垢前体。

Electrically powered heat pump systems will play a key role in providing hot water and heating in domestic and commercial installations as the UK moves away from fossil fuels: these systems are already widely used in locations without ready access to natural gas. Heat pumps rely on efficient heat transfer in condensers, which is compromised by the formation of fouling layers (water scale) arising from hardness salts present in the water. Scale formation increases with water temperature: the next generation of heat pump systems aim to deliver water at 85-90C, so sustainable mitigation methods are required that do not require the use of chemical dosage. The key aims of the research are:(i) to develop quantitative models of scale formation in plate heat exchangers under heat pump operating conditions, so that these can be designed to minimise the rate of growth of fouling layers; (ii) to quantify the impact of surface treatment and water pretreatment strategies on fouling rates at these higher temperatures, and (iii) to determine the effectiveness of post-exchanger passive capture technologies to prevent detached scale or fouling precursors from the heated water.