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获得性已变得越来越重要。人们还认识到，虽然开发新能源是必要的，但有意识地努力节约和更明智地使用能源也是必要的。长期以来，建筑一直被认为是提高能效的主要关注点，最雄心勃勃的努力是实现净零能源目标。新的更高效的热水策略对实现这一目标至关重要，因为水加热是加拿大住宅的第二大能源消耗，约占总能源消耗的18%(每户19GJ)。**太阳能家用热水(SDHW)系统已被证明是一种成本效益高且可靠的水加热方法，可以降低住宅建筑的一次能源消耗。然而，在北方气候中，SDHW系统需要一个备用热源，以便在太阳能输入不足的时期提供额外的热能。可以使用电阻加热器来提供这种备用加热，其中热输入和电输入的比例为1：1。或者，可以使用热泵，根据运行条件的不同，热输入和电输入的比例可以在3：1或10：1的范围内。从热力学的角度来看，利用这种电力来运行热泵是一种更有效的能源利用方式。**热泵和SDHW技术的协同结合，为家庭提供热水或空气，被称为太阳能辅助热泵(SAHP)。除了更好地利用电力外，热泵还可以预冷流向太阳能吸收器的流体。较低的流体供应温度将减少吸收塔的热损失，从而提高系统效率并延长系统在较冷天气下的运行时间。更重要的是，如果SAHP能够在不需要热泵的情况下恢复到标准的SDHW系统，那么该系统就有可能满足节能建筑的全年需求。消除对备用热源的需求将会带来额外的好处，即降低系统的资本成本。然而，要达到这一点，这些系统需要进一步开发。特别是，需要评估部件尺寸和可靠性、智能控制策略以及系统与建筑物和居住者要求的相互作用，以使SAHP发挥其最大潜力。**拟议的研究将解决当前SAHP技术的一些关键限制。总体目标是开发强大、可靠和经济可行的SAHP系统，开发设计工具，使建筑商和房主能够就该技术做出明智的选择，并在与太阳能和建筑科学相关的领域培训HQP。最终，这将有助于减少建筑物的能源需求，从而使加拿大受益。在接下来的五年中，拟议的计划将解决几个短期目标。首先，将对几种新型的纯太阳能SAHP系统配置进行分析和实验研究，从而建立准确的系统模型。这些模型将被用来开发创新的控制策略，使SAHP能够以最高效率运行。下一步，将评估这些系统与其他新型节能技术的兼容性，如热回收和光伏/太阳能热混合动力。最后，将构建和运行这些系统，以在真实世界环境中评估系统的健壮性。与任何建筑技术一样，有效运行的关键是根据系统的位置和使用特点来理解和开发系统。