A study on the reduction of CaCO3 fouling in hot-water storage tank by short pulse plasma application (rev 1 yc)

The present study investigated the feasibility of using plasma spark discharge to prevent mineral fouling on the coil heat exchanger in a hot-water storage tank, which is used in a large heat pump system. Experimental fouling test was conducted with spark discharges produced directly in water inside the tank. The overall heat transfer coefficient was determined from both flow rate and four temperatures measured at the inlet and outlet of the coil heat exchanger. The artificial hard water was used to accelerate the fouling process on the heat exchanger surface. The test results showed that the fouling in the coil heat exchanger was effectively suppressed using plasma application. For the case of 1250-ppm solution, the fouling resistance was reduced by 66% with plasma application compared with no-treatment case. The spark discharge plasma application can be a useful method to reduce the mineral fouling on the coil heat exchanger in a hot-water storage tank.