SBIR Phase I: Heat Pipe for Ground Source Heat Pump

这个小型企业创新研究（SBIR）第一阶段项目将开发一种地球热交换器，它比目前可用的地源热泵具有更低的安装成本、更低的运行成本和更小的占地面积。尽管地源热泵技术具有效率优势，但高昂的地面回路安装成本是其被广泛接受的主要障碍。通过用“热管”装置取代循环液体管道，“热管”装置由封闭管道组成，其中含有饱和工作流体，该流体在热管内的不同位置循环蒸发和冷凝，从而提高了地球与热泵制冷剂之间的传热效率。热管换热器在加热模式下不需要电力，在冷却模式下只需要非常少量的电力。一种蒸汽压低、无毒、廉价且不会对地下水造成潜在污染的新型工作流体已经被发现。该项目的成功完成将使热管换热器的安装和操作更加经济。这项研究的更广泛/商业影响是更多地采用地源热泵，这是最有效的加热和冷却手段。热管将具有较低的内部热阻，并将使用比CLPS更大的管径，这将增加单位长度的接触表面积。这将减少钻孔/挖沟，简化安装，降低安装成本。安装成本和占地面积的显著降低可以增加新建筑和改造应用的采用。到2012年，全球对暖通空调设备的需求将以每年5%的速度增长，超过700亿美元。美国市场以每年3.2%的速度增长，2009年超过140亿美元。这项新技术将被授权给热泵制造商。

This Small Business Innovation Research (SBIR) Phase I project will develop an earth heat exchanger that has a lower installation cost, lower operating cost, and smaller footprint than the currently available ground source heat pumps. High ground loop installation costs are the primary barrier to broader acceptance of ground source heat pump technology despite its efficiency advantage. By replacing the circulating liquid pipes with a "heat-pipe" arrangement which consists of a closed pipe containing a saturated working fluid which is cyclically evaporated and condensed at different locations within the heat-pipe, heat transfer efficiency between the earth and the heat pump refrigerant is increased. A heat-pipe heat exchanger would require no electricity in heating mode and only a very small amount of electricity in cooling mode. A novel working fluid which has a low vapor pressure, is non-toxic, inexpensive, and is not a potential ground water contaminant has been identified. Successful completion of this project will result in a heat-pipe exchanger that is more economical to install and operate.The broader/commercial impacts of this research are increased adoption of ground source heat pumps, the most efficient means of heating and cooling. The heat-pipe will have a lower internal thermal resistance and will use a larger pipe diameter than CLPS which will increase the contact surface area per unit length. This will allow less boring/trenching, will simplify installation, and will lower installation costs. A significant reduction in the cost and footprint of installations could increase adoption in both new building and retrofit applications. World demand for HVAC equipment will rise more than five percent per year through 2012, exceeding $70 billion. The US market is growing at 3.2% per year and exceeded $14B in 2009. The new technology will be licensed to heat pump manufacturers.