Structure for controlling temperature of hot-water supply from waste heat recovery system using three-way valve or mixing valve, and structure for controlling temperature of hot-water supply from waste heat recovery system using heat exchanger in hot-water tank

Abstract

The present invention relates to a structure for controlling a temperature of hot-water supply from a waste heat recovery system, and more particularly, to a structure for controlling a temperature of hot-water supply from a waste heat recovery system using a three-way valve capable of stably supplying hot water at a hot-water supply setting temperature during hot-water supply use using the three-way valve and saving energy to improve system efficiency, in a waste heat recovery system recycling waste heat.

1 . A structure for controlling a temperature of hot-water supply from a waste heat recovery system using a three-way valve, comprising:
 a hot-water tank having a waste heat exchanger for recovering waste heat from a waste heat source to generate hot water, a heating heat exchanger for exchanging heat using the hot water so as to provide heating, and a temperature sensor for checking a temperature of the hot water, to store the hot water heat-exchanged by the waste heat exchanger;   a boiler heating the heat-exchanged hot water from the hot-water tank to satisfy a temperature set by a user for heating and hot-water supply and supplying the heated hot water to a heating space and a hot-water supply space;   a three-way valve installed in a hot-water line introduced from the hot-water tank to the boiler to selectively supply hot water or direct water flowing from the hot-water tank to the boiler; and   a controller controlling the three-way valve to block the hot water flowing in from the hot water tank and supplying the direct water to the boiler when it is checked by the temperature sensor that the temperature of the hot-water tank is 0° C. to 10° C. lower than the hot-water supply setting temperature of the boiler.   
     
     
         2 . A structure for controlling a temperature of hot-water supply from a waste heat recovery system using a mixing valve, comprising:
 a hot-water tank having a waste heat exchanger for recovering waste heat from a waste heat source to generate hot water, a heating heat exchanger for exchanging heat using the hot water so as to provide heating, and a temperature sensor for checking a temperature of the hot water, to store the hot water heat-exchanged by the waste heat exchanger;   a boiler heating the heat-exchanged hot water from the hot-water tank to satisfy a temperature set by a user for heating and hot-water supply and supplying the heated hot water to a heating space and a hot-water supply space;   a mixing valve installed in a hot-water line introduced from the hot-water tank into the boiler to mix hot water flowing in from the hot-water tank with direct water and supplying the mixed water to the boiler; and   a controller  150  controlling the mixing valve after determining the amount of direct water to be mixed in the hot-water line to which the hot water of the hot-water tank is discharged when it is checked by the temperature sensor that the temperature of the hot-water tank is 0° C. to 10° C. lower than the hot-water supply setting temperature of the boiler  120 .   
     
     
         3 . The structure of  claim 2 , wherein the controller uses a PID control algorithm using feedback to determine the amount of direct water to be mixed in the hot-water line to which the hot water of the hot-water tank is discharged. 
     
     
         4 . A structure for controlling a temperature of hot-water supply from a waste heat recovery system using a heat exchanger in a hot-water tank, comprising:
 a hot-water tank having a waste heat exchanger for recovering waste heat from a waste heat source to generate hot water, a heating heat exchanger for exchanging heat using the hot water so as to provide heating, and a temperature sensor for checking a temperature of the hot water, to store the hot water heat-exchanged by the waste heat exchanger;   a boiler heating the heat-exchanged hot water from the hot-water tank to satisfy a temperature set by a user for heating and hot-water supply and supplying the heated hot water to a heating space and a hot-water supply space;   a three-way valve installed in a hot-water line introduced from the boiler into the heating space to selectively supply a heat medium flowing in from the boiler to the heating space or a recirculated water line; and   a controller controlling the three-way valve to block the heat medium flowing in from the boiler into the heating space and directly introducing the heat medium into the heating heat exchanger of the hot-water tank through the recirculated water line so as to heat the hot water of the hot-water tank when it is checked by the temperature sensor that the temperature of the hot-water tank is 0° C. to 10° C. lower than the hot-water supply setting temperature of the boiler.   
     
     
         5 . The structure of  claim 4 , further comprising:
 a three-way valve having different inlets each connected to the recirculated water line and a water outlet line of the heating heat exchanger and an outlet connected to a heating recirculation water port of the boiler to selectively supply a heat medium introduced from the recirculated water line or a heat medium introduced from the heating heat exchanger to the boiler,   wherein the controller controls the three-way valve to block the heat medium discharged from the water outlet line of the heating heat exchanger and introduces the heat medium discharged from the recirculated water line into the boiler when the temperature of the heat medium discharged from the recirculated water line is determined to be higher than the hot water temperature of the hot-water tank using the temperature sensor.