在加速试验条件下，在四个不同的美国城市运行了传统的燃气和电存储式家用热水器，以测量结垢对效率的影响，并评估常用水处理方法的优点和局限性。所选的四个试验地点都有硬水供应，具有预期的结垢趋势，位于俄亥俄州哥伦布；伊利诺伊州利斯；新墨西哥州罗斯韦尔；还有明尼苏达州的马歇尔。主要结论如下。在其中两个试验现场累积60磅（27千克）的水垢后（相当于估计20年的等效水垢累积），燃气热水器的效率逐渐下降约5%，而电热水器的效率保持不变。 然而，电加热器中的积垢导致电加热元件周期性故障，而在燃气加热器中，它导致燃烧器附近的罐金属温度升高。处理过的水（软化水、软化水加聚磷酸盐或硬水加聚磷酸盐）有效地减少了结垢，并倾向于降低金属试样在热水中的腐蚀速率。然而，在使用任何类型软化水的储罐中，牺牲镁阳极的消耗率要高得多，这可能间接导致这些储罐更快地发生腐蚀。这项研究提出了几项设计建议，预计可以最大限度地减少结垢和阳极氧化- 电加热器和正在开发的新型、更高效的燃气热水器存在腐蚀问题。单位:双引文:研讨会，ASHRAE交易，1986年，第92卷，pt。2B，波特兰，或

Conventional gas and electric storage-type residential water heaters were operated at four different U.S. cities under accelerated test conditions to measure the effect of scale buildup on efficiency and to assess the benefits and limitations of common water treatment methods. The four Selected test sites had hard water supplies with expected scale-forming tendencies and were located in Columbus, OH; Lisle, IL; Roswell, NM; and Marshall, MN.The main conclusions are as follows. After 60 lbs (27 kg) of scale buildup at two of the test sites (representing an estimated 20 years of equivalent scale buildup), the efficiency the gas water heaters gradually declined about 5%, while that of the electric water heaters remained constant. However, the buildup of scale in the electric heaters caused the electric heating element to fail periodically, and in the gas-fired heaters, it caused the tank metal temperatures near the burner to operate hotter. Treated water (either softened, softened plus polyphosphate, or hard plus polyphosphate) effectively reduced scale buildup and tended to reduce the corrosion rates of the metal test coupons in hot water. However, the sacrificial magnesium anodes were consumed at a much higher rate in the tanks using any type of softened water, and this could indirectly cause those tanks to experience corrosion sooner.Several design recommendations resulted from this study that are expected to minimize scale buildup and anode-corrosion problems in electric heaters and in the newer, more efficient, gasfired water heaters that are being developed.Units: Dual