Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D19/00—Details
  • F24D19/10—Arrangement or mounting of control or safety devices
  • F24D19/1006—Arrangement or mounting of control or safety devices for water heating systems
  • F24D19/1066—Arrangement or mounting of control or safety devices for water heating systems for the combination of central heating and domestic hot water
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D10/00—District heating systems
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
  • Y02B30/17—District heating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E20/00—Combustion technologies with mitigation potential
  • Y02E20/14—Combined heat and power generation [CHP]

Definitions

• Heating system for space heating and tap water heating.
• the invention relates to a heating system for space heating and tap water heating by the same heating medium, comprising a regulator which decreases respectively increases the flow of the heating medium to a space heating device if a monitoring means signals an increased respectively decreased demand for tap water heat, and a heat exchanger between heating medium and tap water, said monitoring means monitors therefor the temperature of a wall, which is in direct heat exchanging relationship with the cold water in the supply conduit of the heat exchanger and is positioned such that it is heated by the heating medium.
• Such a system is known in various embodiments.
• a flow-through water heater for tap water heating is connected to a boiler through open supply- and discharge connections, where by the monitoring means is mounted on said boiler such, that if no water is tapped said means are heated by the water heater through heat conduction.
• Said mondtoring means actuates at. circulation valve in the space heating system, such that when warm water is tapped the connection between the space heating system and the boiler is interrupted and a circulation can be maintained in said system.
• the invention aims to improve known systems of this type such that also in a small scale configuration a high efficiency is achievable in a cheap embodiment.
• a system as mentioned above is according to the invention characterized in that said wall is furthermore at the other side in direct heat exchanging relationship with the heating medium at such a spot in the path thereof, that it flows along said spot if it flows to the heat exchanger for tap water heating, and that said regulator opens and closes the supply of the heating mediumn to the heat exchanger for tap water heating at respectively lower and higher temperature of said wall.
• the system according to the invention has small dimensions, has associated with said dimensions low insulation losses and therefore a high efficiency, whereas the heat exchanger can advantageously be so configurated that at the main distant tap point, hot tap water of the right temperature is immediately available.
• the regulator influences more directly the flow of the heating medium to the tap water heater and because the regulator tries, to maintain a constant temperature of said wall, along which the heating medium flows if it heats the tap water, it is possible to keep the temperature of the tap water constant within broad limits nearly independent of the tapped water volume and the temperature of the heating medium.
• the invention further relates to a more specified realisation of this principle, both for installations with their own heating source (boiler) and for installations connected to a district heating system, which will become clear from the following description of some embodiments of ( parts of ) a system according to the invention, illustrated in the accompanying figures.
• a heating source for installations with their own heating source (boiler) and for installations connected to a district heating system
• Fig. 1 a diagram of a system according to a preferred embodiment of the invention
• Fig. 2 a sectional view along line II-II in Fig.3 through the regulatd&j as used in said system;
• Fig. 3 a sectional view along line III-III in Fig.2 through said regulator;
• Fig. 4 a possible embodiment of a heat exchanger for the tap water heating
• Figs. 5, 6 and 7 show possible embodiments of the tube respectively the tube system of this heat exchanger.
• the system according to Fig. 1 comprises a boiler 1, a space heating device 2, such as a set of radiators, a heat exchanger 3 for tap water heating and tap points, of which one is shown and referenced by 4.
• a regulator 5 is mounted in the conduit 6, through which the heating medium arrives from boiler 1.
• the regulator connects said conduit 6 to a conduit 7 leading to said device 2 or to a conduit 8 leading to said tap water heat exchanger 3.
• a return conduit 9 the medium from device 2 or heat exchanger 3 returns back into the boiler, for which purpose the exchanger 3 is connected to conduit 9 by return conduit 12.
• This option should be considered in particular if not a boiler 1 is used as heating source, but an external source such as in a district heating system, whereby it is important and often required that the return flow has a low temperature.
• the boiler 1 is then substituted by a supply conduit 15, which supplies external heated medium at high temperature, and a return conduit 16, which returns medium after withdrawing a part of the heat therefrom.
• a shaft 17 is journalled in appropriate guidances in the housing of the regulator to be movable in axial direction in said housing and said shaft supports a valve body 18, movable between an upper seat 19 and a lower seat 20.
• the conduit 6 (Fig. 1) is connected, which supplies heating medium from the boiler. This port is communicating via a passage along seat 19 and through space 22 to conduit 7 leading to the space heating device 2 and via a passage along seat 20 and through space 23 to conduit 11 leading to the tap water heater (exchanger 3).
• Space 23 contains a tubular body 24, which is mounted with sealing rings 25 in holding rings 26 of heat insulating material, for instance a temperatureproof hard plastic, porcelain or the like, which are sealingly mounted in the house of regulator 5.
• This body can, as shown, be configurated as a simple short tubelet, for instance of copper alloy.
• the interior of the tubular body 24 is communicating with conduit 10 via a port 27, which conduit 10 supplies cold tap water. Tap water flowing through the tubelet 24, and can thereafter leave the housing of the regulator at 28 (Fig.3), flowing to conduit 11, which leads to heat exchanger 3.
• tubular body 24 is provided with a temperature sensor 29 , mounted in a tubelet which is thermally insulated from the regulator housing, such that also a medium tight passage through the wall of the housing for a sensor line connected to said sensor is provided.
• a control amplifier is installed, with a drive motor for shaft 17, which is actuated dependent of the signals of said sensor, whereby an overload protection can be realised based on signaling of the fact that valve body 18 has reached one of its seats.
• a by-pass conduit 14 shown in dashlines can be mounted between the conduits 7 and 9 as will be described later.
• this device is as follows: If there is no demand for warm tap water the boiler 1 will provide the space heating device 2 with heating medium in the usual way through conduit 6 and regulator 5, in which situation the valve body 18 is In the lowest position in Fig. 2 onto seat 20, such that the medium which enters at 21 leaves the regulator through 22 to conduit 7. Through the return conduit 9 the cooled medium returns to the boiler. In a district heating system this heated medium enters through 15 and flows, cooled down, back through 16. The whole housing of regulator 5 is now hot and the hot heating medium which earlier flowed for tap water heating through seat 20 to space 23, as well as the initially cold tap water in the tubelet 24, have also reached approximately the temperature ofcthe housing 5 after a sufficient long stand still. However, after a considerable period of time without any demand for space heating or tap water, the situation is different as will be described below.
• the distances between the isolating rings 26 and space 23 around the tubular body are chosen relative to the inner diameter of the tubular body 24, such that the surfaces of the passages for the heating medium and the tap water have a certain relationship to each other. This relationship is such that the flow rates of the heating medium and the tap water are equal at average entering temperature of the heating medium and of the (cold) tap water and at the desired final temperature of the tap water (which is approximately equal to the temperature of the heating medium at the output of exchanger 3).
• the control amplifier is configurated such that it tries to maintain a fixed set temperature of the tubular body 24 by increasing or decreasing the opening between the valve body 18 and the seat 20.
• the heat flow from the heating medium via the wall of the tubular body 24 to the (still cold) tap water, and associated therewith the temperature of the tubular body 24, which is measured by the temperature sensor 29, is defined by the flow rate of the heating medium and of the cold tap water, by the temperature of the heating medium and the tap water respectively, and by the surfaces of the tubular body 24, respectievely in contact with the heating medium and the tap water.
• the relationship between both said surfaces is chosen such that the final temperature of the tap water remains for the present purpose sufficiently constant within broad limits.
• the device is insensitive for pressure variations in the heating medium and tap water because only the flow speed in and around the trubular body 24 has any influence.
• a speed variation caused by pressure differences for instance along the seat 20 is compensated by another setting of valve body 18.
• the speed of the tap water in the tubular body 24 will also change or reduce to zero as result of which the temperature measured by sensor 29 changes and the opening between the valve body 18 and the seat is changed or completely closed.
• the heat exchanger 3 will.be described now.
• such a heat exchanger can be configurated as a long double walled tube, which ends preferably near one of the tap points (e.g. 4).
• heat exchanger 3 needs of course a external insulation 30, but the assembly can be maintained relatively thin. If the main tap point is placed so near to the regulator 5 that the shortest distance therebetween is smaller than the preferred length of heat exchanger 3, embodied tubular, then this tube can have a meandering shape along some distance or along the entire distance, i.e. partitially folded back, with some insulation therebetween, as is shown in Fig. 4. Preferably the three tube sections are not in a same plane but situated in a triangular pattern to maintain a small external diameter.
• a heat exchanger 13 If a heat exchanger 13 is applied one can build this together with the exchanger 3 as two adjacent double walled tubes in the same insulation, with inputs 8 and 11, a tap water conduit 10 to the regulator and the return conduit 12 at the end of this assembly near the regulator 5.
• Fig. 5 shows how the external tube can be pinched locally to contact and so support the internal tube, which pinching can be done for instance with a simple pair of pliers at uniform intervals of for instance 30 cm. Also a helically extending wire, for instance of metal, could be positioned between the internal and external tube.
• Fig. 6 shows a ribbed tube, at which tube ribs are extending straight or helically. A smooth tube can be externally mounted to form the double walled heat exchanger.
• Fig. 7 shows a double walled tube, made integrally with bridges 31 for the connection between the internal and external tube. This tube can be used as internal tube, by which an almost complete "double barrier" is created between tap water and (possibly polluted) heating medium. Heat exchangers according Fig. 5 and therefrom derivated can be fairly easily bent at site.
• the following may be useful: if a heat exchanger 13 is used, the quantity of heat medium has to be smaller and the internal dimensions of the regulator have to be adapted.
• the boiler comprises in a known way an own return (by-pass) conduit to maintain circulation, and normally also comprises a circulation pump.
• a circulation pump is often switched off in time periods during which no space heating is required.
• the heat exchanger 3 adapts the final temperature of the tap water. This is possible by correctly selecting the volume of the tap water and that of the heating medium in the exchanger 3 without counting for insulation losses, in other words by using appropriate tube diameters.
• a more elegant solution comprises of course that the temperature of the exchanger 3 is measured at a convenient place and that at a deviating (lower) temperature a signal is delivered to the regulator 5 to let the heating medium flow to the exchanger 3, without withdrawing tap water. After adaption, this second signal can be easily processed together with the signal of the temperature sensor 29 in the control amplifier. In this way the temperature of the exchanger 3 can be much better maintained constant in time periods in which no tap water is withdrawn, than with the described process in which a volume of heating medium is supplied depending onto the circumstances.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Steam Or Hot-Water Central Heating Systems (AREA)

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• 1981
  • 1981-10-26 NL NL8104824A patent/NL8104824A/nl not_active Application Discontinuation
• 1982
  • 1982-10-25 WO PCT/NL1982/000039 patent/WO1983001499A1/en not_active Ceased
  • 1982-10-25 EP EP82903191A patent/EP0091931A1/de not_active Withdrawn

Non-Patent Citations (1)

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