{"id":645,"date":"2007-03-01T20:49:54","date_gmt":"2007-03-01T20:49:54","guid":{"rendered":"https:\/\/informatech.energir.com\/?p=645"},"modified":"2021-04-15T15:34:28","modified_gmt":"2021-04-15T20:34:28","slug":"direct-contact-technology-operation-applications-and-savings","status":"publish","type":"post","link":"https:\/\/informatech.energir.com\/?p=645&lang=en","title":{"rendered":"Direct contact technology: Operation, applications and savings"},"content":{"rendered":"

Hot water boilers using direct contact heat transfer between combustion gases and water are recognized for their high energy efficiency. To achieve this full energy potential, it is essential to use them in a suitable application.<\/p>\n

Operating principle<\/p>\n

The heat transfer principle is simple (Figure 1). High-temperature combustion gases in the region of the flame become saturated with water by evaporation of descending water. This water vapour condenses again when it comes into contact with the stainless steel nodules, kept relatively cold by the water jets at the inlet. At the outlet of this nodule section, the combustion gases encounter an even colder environment as they pass under the cold shower. The combustion gases thus are cooler and exit the water heater at a temperature close to the water inlet temperature.<\/p>\n

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Figure 1: Direct contact water heater<\/figcaption><\/figure>\n\"\"<\/a><\/p>\n

The colder the water temperature at the water heater inlet, the colder the products of natural gas combustion will be when they emerge, and the closer they will propel the direct contact water heater’s thermal efficiency to 100%.<\/p>\n

Given that the combustion gases come into direct contact with water, it is important to verify whether the low concentrations of contaminants coming from these gases have an effect on the process. If such is the case, it is possible to operate with a primary and secondary loop system. This prevents the process water from coming into contact with the water from the water heater. Given that this technology triggers condensation of combustion products, natural gas becomes the choice energy source. In some applications, these water heaters can reach a thermal efficiency of 99%.<\/p>\n

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Typical applications recommended<\/td>\n<\/tr>\n
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