Abstract: Provided is a method for controlling a cascade boiler system, and the method includes a) operating the number of boilers set in an initial operation state, b) detecting a supply water temperature and a returned water temperature of the primary side of the hydro-separator and a supply water temperature and a returned water temperature of the secondary side, and calculating a flow rate corrected by the hydro-separator using the detected temperatures, c) calculating a set temperature serving as the supply water temperature of the primary side that is able to maintain the supply water temperature of the secondary side when the supply water temperature of the secondary side is within a set range of a target temperature while maintaining the initial operation state, and d) calculating the number of boilers that are able to maintain the calculated set temperature, and controlling an operation of the boilers according to the number.

Abstract: The present invention relates to a method for manufacturing a low density inorganic powder insulator having a low density molded structure using expanded perlite without a binder and a mold machine for manufacturing the same, and more particularly, to a technology of uniformly dispersing perlite particles having a shape of irregular fragments of glass using expanded perlite to form a framework among synthetic silica to improve molding strength even at a low density, thereby reducing thermal conductivity (conduction and convection blocking) due to a low density and an increase in a specific surface area.

Abstract: A method for controlling a parallel operation of a multi-water heater in which a plurality of water heaters are connected to each other in parallel, according to the present invention, comprises: measuring the temperature of direct water that flows into the multi-water heater; sensing a set temperature set by a user; calculating a temperature difference between the set temperature and the direct water temperature; and changing a reference value to additionally operate or stop each water heater according to the calculated temperature difference, thereby efficiently operate the multi-water heater even though the circumstance and conditions of use are changed.

Abstract: The present invention relates to a thermal insulator using closed cell expanded perlite. The thermal insulator using closed cell expanded perlite of the present invention includes: expanded perlite 10 to 84 wt %ç, including dried and expanded perlite ore particles, having a surface with a closed cell shape, as an active ingredient; a liquid binder 15 to 85 wt %; and a reinforcing fiber 0.25 to 5 wt %. Accordingly, the present invention provides a thermal insulator, which enhances the rigidity of expanded perlite, minimizes porosity and gaps between the expanded perlite particles, by reducing compression ratio during compression molding, which results in lower density, improves constructability by lowering thermal conductivity, reduces material and energy costs and can reduce the area required for equipment installation by reducing the thickness of the thermal insulator.

Abstract: A method for controlling the temperature of hot water through an operation of a circulation pump according to the present invention includes: judging whether a user uses the hot water; judging whether one of the circulation pump operating modes is selected; and circulating the hot water in an outflow pipe to an inflow pipe by operating the circulation pump provided on a bypass pipe connecting the inflow pipe which direct water enters and the outflow pipe through which heated hot water flows out to each other when the user uses the hot water and selects one of the circulation pump operating modes, thereby controlling a temperature difference of the hot water that flows out from a water heater to be reduced.

Abstract: The present invention relates to a thermal insulator using closed cell expanded perlite. The thermal insulator using closed cell expanded perlite of the present invention includes: expanded perlite 10 to 84 wt %,ç, including dried and expanded perlite ore particles, having a surface with a closed cell shape, as an active ingredient; a liquid binder 15 to 85 wt %; and a reinforcing fiber 0.25 to 5 wt %. Accordingly, the present invention provides a thermal insulator, which enhances the rigidity of expanded perlite, minimizes porosity and gaps between the expanded perlite particles, by reducing compression ratio during compression molding, which results in lower density, improves constructability by lowering thermal conductivity, reduces material and energy costs and can reduce the area required for equipment installation by reducing the thickness of the thermal insulator.

Abstract: In a hot water supply system, a heat exchanger transfers heat from a heating device to inflow water to supply the inflow water at a user-set temperature. A flow sensor measures a flow rate of inflow water. A water tank stores outflow water discharged from the heat exchanger. A first temperature sensor, installed on an inlet pipe through which the inflow water flows, measures a temperature of the inflow water. A second temperature sensor, installed on an outlet pipe through which the outflow water flows, measures a temperature of the outflow water discharged from the heat exchanger. A controller includes an input unit to receive input from a user, wherein the controller controls an operation of the heating device based on at least one of: (1) comparison between the user-set temperature and the temperature of the outflow water; (2) variation in the flow rate; or (3) any combination thereof.