System for the Heating of Two Mutually Separated Liquids

Abstract

The invention relates to a system for heating two mutually separated liquids, wherein a first liquid is intended for heating a building and wherein the second liquid is tap water.

1 . A system for heating two mutually separated liquids, wherein a first liquid is intended for heating a building and wherein the second liquid is tap water, which system comprises:
 a device for heating the first liquid, the device comprising:
 a housing with an air feed, a fuel feed and a flue gas discharge; 
 a burner disposed in the housing for combusting fuel and air supplied to the burner while releasing flue gases, which burner is connected on the one hand for medium throughflow to the fuel feed and the air feed and is connected on the other for medium throughflow to the flue gas discharge; 
 a first heat exchanger connected for medium throughflow to the flue gas discharge for the purpose of transferring heat from the flue gases to the first liquid in order to heat the first liquid; 
   a second heat exchanger disposed downstream of the first heat exchanger for transferring residual heat from the flue gases to the tap water in order to preheat the tap water;   a third heat exchanger disposed downstream of the first heat exchanger and the second heat exchanger for transferring heat from the first liquid to the preheated tap water in order to further heat the preheated tap water,   characterized by   a reservoir for storing tap water, which reservoir is disposed downstream of the third heat exchanger and connected for medium throughflow thereto by means of a first conduit, wherein the conduit debouches in an upper part of the reservoir such that the tap water heated in the third heat exchanger is delivered during use into the upper part of the reservoir, and wherein the reservoir is on the other hand connected for medium throughflow by means of a second conduit to the second heat exchanger and disposed upstream thereof, which second conduit is connected to a lower part of the reservoir for the purpose of supplying tap water from the lower part of the reservoir to the second heat exchanger.   
     
     
         2 . The system as claimed in  claim 1 , further comprising a draw-off conduit which debouches in an upper part of the reservoir for the purpose of drawing off the heated tap water stored in the reservoir. 
     
     
         3 . The system as claimed in  claim 1 , wherein the reservoir comprises a tube which is disposed vertically therein and via which the conduit is connected to the reservoir, wherein the tube encloses the conduit and debouches in the upper part of the reservoir via a first opening, wherein the conduit debouches at a predetermined height in the tube, and wherein the tube has a number of second openings debouching in the reservoir, each at a predetermined height which is lower than the height at which the conduit debouches in the tube, for the purpose of delivering tap water at a temperature lower than a maximum temperature of the tap water to the reservoir such that the tap water is delivered via this second opening to the reservoir where the temperature of the tap water is equal to or lower than the temperature of the tap water stored at this height. 
     
     
         4 . The system as claimed in  claim 3 , wherein the predetermined height lies at between 40-75% of the height of the reservoir, preferably between 50-65% of the height of the reservoir, more preferably at about 60% of the height of the reservoir. 
     
     
         5 . The system as claimed in  claim 3 , wherein the tube comprises three second openings which preferably debouch in the reservoir at respectively between 15-20%, 22-28% and 30-35% of the height of the reservoir. 
     
     
         6 . The system as claimed in  claim 1 , wherein the tube is manufactured from a thermally non-conductive material. 
     
     
         7 . The system as claimed in  claim 2 , further comprising a three-way valve, which three-way valve is connected for medium throughflow to the second heat exchanger on the one hand and to the second conduit and the draw-off conduit on the other, wherein the three-way valve is adjusted such that at a random moment either the second conduit or the draw-off conduit is connected for medium throughflow to the second heat exchanger for the purpose of feeding to the second heat exchanger tap water coming from either the second conduit or the draw-off conduit such that tap water present either at the bottom of the reservoir or at the top of the reservoir is supplied to the second heat exchanger. 
     
     
         8 . The system as claimed in  claim 7 , wherein the three-way valve is set such that the draw-off conduit is connected for medium throughflow to the second heat exchanger only when power for heating the building is demanded which lies below a minimum power which can be supplied by the device for heating the first liquid. 
     
     
         9 . The system as claimed in  claim 7 , wherein the three-way valve is set such that, when the reservoir is filled with a predetermined percentage or more of heated tap water, the draw-off conduit is connected for medium throughflow to the second heat exchanger. 
     
     
         10 . The system as claimed in  claim 9 , wherein the predetermined percentage lies between 70-100%. 
     
     
         11 . The system as claimed in  claim 9 , comprising a number of temperature sensors disposed at predetermined heights in the reservoir for measuring the temperature of the tap water at this height, and wherein the three-way valve is adjustable on the basis of the measured temperatures.