Development of Solar Assisted Heat Pump Water Heating Systems

太阳能辅助热泵热水系统的开发

• 批准号: RGPIN-2014-04295
• 负责人: Collins, Michael
• 金额: $ 1.75万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647942
• 关键词: Development; Solar; Assisted; Heat; Pump

The environmental impact and availability of standard energy sources has become increasingly important. It is also recognized that while the development of new energy sources is necessary, so too is a conscious effort towards conservation and smarter use of energy. Buildings have long been considered a primary focus for energy efficiency, with the most ambitious efforts aimed at net-zero energy targets. New and more efficient water heating strategies are critical to meeting this goal, as water heating is the second largest energy consumer in Canadian residences at approximately 18% of total energy consumption (19 GJ of energy per household).**Solar Domestic Water Heating (SDHW) systems have proven to be a cost effective and reliable method of water heating that reduces primary energy consumption in residential buildings. In northern climates, however, SDHW systems require a back-up heat source to provide additional thermal energy during period of insufficient solar input. One could use an electrical resistance heater to provide this back-up heating, where the ratio of heat input to electrical input is 1:1. Alternatively, one could use a heat pump, where the ratio of heat input to electrical input could be in the range of 3:1 or 10:1, depending on the operating conditions. From a thermodynamic perspective, using this electricity to run a heat pump is a far more efficient use of energy.**The synergistic combination of heat pump and SDHW technologies to provide hot water or air for domestic purposes is called a Solar Assisted Heat Pump (SAHP). In addition to being a better use of electricity, the inclusion of a heat pump will pre-cool the fluid going to the solar absorber. Colder fluid supply temperatures will reduce thermal losses from the absorber, thereby improving system efficiency and increasing system run-time in colder weather. More importantly, if the SAHP is capable of reverting to a standard SDHW system when the heat pump is not needed, there is potential that the system could meet the year round demands of an energy efficient building. Removing the need for back-up heat sources would have the added benefit of reducing the capital cost of the system. To get to that point, however, the systems need further development. In particular, component sizing and reliability, smart control strategies, and system interaction with building and occupant requirements need to be assessed in order for the SAHP to reach its maximum potential.**The proposed research will address some critical limitations of current SAHP technologies. The overarching goal is to develop robust, reliable, and economically viable SAHP systems, to develop design tools that will allow builders and homeowners to make informed choices about the technology, and to train HQP in fields related to solar energy and building sciences. Ultimately, this will benefit Canada by helping reduce the energy demands of buildings. Over the course of the next five years, the proposed program will address several shorter term objectives. Initially, several novel solar-only SAHP system configurations will be investigated both analytically and experimentally, resulting in accurate models of the systems. These models will be used to develop innovative control strategies which will allow the SAHP to operate at peak efficiency. Next, the compatibility of the systems with other novel energy efficient technologies, such as heat recovery and photovoltaic/solar thermal hybrids, will be assessed. Finally, the systems will be built and operated to assess system robustness in a real world setting. As with any building technology, the key to efficient operation is to understand and develop the system in the context of its location and usage characteristics.

标准能源的环境影响和可用性变得越来越重要。人们还认识到，尽管有必要开发新的能源，但有意识地努力保护和更智能地使用能源。长期以来，建筑物一直是能源效率的主要重点，最雄心勃勃的努力旨在净零能源目标。新的，更高效的水加热策略对于实现这一目标至关重要，因为水是加拿大住宅中第二大能源消费者，约占总能源消耗的18％（每个家庭能源19 gj）。但是，在北部气候下，SDHW系统需要备用热源，以在太阳能输入不足的时间内提供额外的热能。可以使用电阻加热器提供此备用加热，其中热输入与电输入的比率为1：1。另外，可以使用热泵，在该热泵中，取决于工作条件，热输入与电输入的比率可能在3：1或10：1的范围内。从热力学的角度来看，使用这种电能运行热泵是能量的有效利用。除了更好地利用电力外，加热泵还将预先冷却到太阳能吸收器的液体。较冷的液体供应温度将减少吸收剂的热损失，从而提高系统效率并在寒冷天气下增加系统运行时。更重要的是，如果SAHP能够在不需要热泵时恢复到标准的SDHW系统，则该系统有可能满足全年的节能建筑需求。消除对备用热源的需求将带来降低系统资本成本的额外好处。但是，要达到这一点，系统需要进一步开发。特别是，需要评估组件尺寸和可靠性，智能控制策略以及与建筑物和居住者要求的系统互动，以使SAHP发挥其最大潜力。**拟议的研究将解决当前SAHP技术的一些关键局限性。总体目标是开发健壮，可靠且经济上可行的SAHP系统，以开发设计工具，以使建筑商和房主能够对技术做出明智的选择，并在与太阳能和建筑科学有关的领域中培训HQP。最终，这将通过帮助减少建筑物的能源需求来受益。在接下来的五年中，该计划将解决几个较短的任期目标。最初，将在分析和实验中对几种新型的仅太阳能SAHP系统配置进行研究，从而导致系统的准确模型。这些模型将用于制定创新的控制策略，使SAHP能够以峰值效率运行。接下来，将评估系统与其他新型能源有效技术的兼容性，例如热恢复和光伏/太阳热杂种。最后，将建立和操作系统，以评估现实世界中的系统鲁棒性。与任何建筑技术一样，高效操作的关键是在其位置和使用特性的背景下理解和开发系统。