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
  • F24D3/00—Hot-water central heating systems
  • F24D3/10—Feed-line arrangements, e.g. providing for heat-accumulator tanks, expansion tanks ; Hydraulic components of a central heating system
• • 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
  • F24D3/00—Hot-water central heating systems
  • F24D3/10—Feed-line arrangements, e.g. providing for heat-accumulator tanks, expansion tanks ; Hydraulic components of a central heating system
  • F24D3/1008—Feed-line arrangements, e.g. providing for heat-accumulator tanks, expansion tanks ; Hydraulic components of a central heating system expansion tanks
• • 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
  • F24D3/00—Hot-water central heating systems
  • F24D3/10—Feed-line arrangements, e.g. providing for heat-accumulator tanks, expansion tanks ; Hydraulic components of a central heating system
  • F24D3/1008—Feed-line arrangements, e.g. providing for heat-accumulator tanks, expansion tanks ; Hydraulic components of a central heating system expansion tanks
  • F24D3/1016—Tanks having a bladder
• • 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
  • F24D2220/00—Components of central heating installations excluding heat sources
  • F24D2220/04—Sensors
  • F24D2220/046—Pressure sensors

Definitions

• the invention relates to a heat transport system with an assembly of a cold or heat source having connected thereto a conduit system with heat exchangers, and an expansion device connected to the assembly.
• the heat transport system is here of a type which functions with a closed liquid circuit along the heat exchangers and the cold or heat source and under pressure during operation.
• Incorporated on the one hand as source in the liquid circuit is a heating boiler or cold pump or the like in which heat or cold is fed to the liquid circulating in the circuit.
• Incorporated on the other hand in the liquid circuit are radiators and/or convectors or other heat exchangers by means of which cold or heat is relinquished from the liquid to spaces for cooling or heating.
• An air transport system can be applied instead of or in addition to convectors and radiators.
• the invention likewise relates to a cooling installation although, for the sake of the readability of the application, the invention is described hereinbelow only with reference to a heating device.
• Devices of this type comprise an expansion device, usually comprising a liquid reservoir or expansion tank, which takes up the extra volume of liquid created by expansion resulting from heating of the liquid.
• an expansion device usually comprising a liquid reservoir or expansion tank, which takes up the extra volume of liquid created by expansion resulting from heating of the liquid.
• a safety valve is mounted in order to prevent an overpressure in the liquid circuit or the assembly.
• a heating device of this type is described in the European patent (application) s EP 0947777 and EP 0740759 or NL 9400106.
• a feature of this expansion device known from said documents is that a lower pressure prevails in the reservoir or expansion tank relative to the pressure in the liquid circuit (assembly) .
• a pump is used to return liquid into the assembly with the liquid circuit during cooling.
• This pump is situated in a connecting conduit between the assembly with the liquid circuit and the expansion device, and is intended to overcome the pressure difference between the liquid in the reservoir of the expansion device and the liquid in the assembly with the liquid circuit.
• the higher pressure in the assembly with the liquid circuit In order to take up liquid from the assembly with the liquid circuit, during heating of the liquid and the resulting volume increase, use is made of the higher pressure in the assembly with the liquid circuit.
• the liquid By opening of a valve present for this purpose in the connecting conduit between the assembly with the liquid circuit and the expansion device, the liquid can flow into the expansion device from the assembly with the liquid circuit where the higher pressure prevails, to the expansion tank or reservoir of the expansion device until the pressure in the assembly with the liquid circuit has reached a desired lower value.
• the pump and the valve can be activated by a switch mechanism or control, wherein a small decrease or increase in pressure in the assembly with the liquid circuit activates respectively the pump or the valve.
• the valve must be equipped for this purpose with an auxiliary drive.
• the pressure regulation of the assembly with the liquid circuit has hereby become automatic. The pressure of the liquid in the assembly will continue to be held constant within a desired, usually small bandwidth.
• a great problem in dimensioning of the pump and the valve in the known configurations is that undesirable hydraulic effects can occur. If a pump capacity is too great, a pressure can rise uncontrollably high in the assembly with the liquid circuit. Too small a choice of pump capacity has the consequence that, as a result of the decrease in the liquid volume, the cooling process in the assembly with the liquid circuit cannot be followed, resulting in too low a pressure in the assembly with the liquid circuit.
• a similar problem applies for the valve in the connecting conduit between the assembly with the liquid circuit and the expansion device. A valve dimensioned too large allows the pressure in the assembly with the liquid circuit to fall uncontrolledly quickly.
• pressure in the assembly with the liquid circuit can possibly rise too high when, due to rapid heating, the expansion of the liquid in the assembly with the liquid circuit proceeds more rapidly than the quantity of liquid which can be discharged via the valve from the assembly with the liquid circuit to the reservoir or expansion tank of the expansion device.
• control of the pressure in the assembly with the liquid circuit will not be achieved without problem, and undesirable defects can occur as a result of extreme pressure peaks.
• Both the pump and the valve in the connecting conduit between the assembly with the liquid circuit and the expansion device are in practice usually dimensioned too large, and are subsequently modified to the specific conditions by additional measures.
• a measure can consist of a soft-start control with which the pump motor is brought slowly to speed, or a load-dependent rotation speed control by means of for instance a frequency converter.
• a hand-operated second valve with choke function can be arranged connected in series to the valve in order to realize a desired liquid speed.
• Another problem of known heating systems or an entirely different order relates to the setting into operation of an expansion device of this type with pump and valve.
• the pump still contains air, it functions poorly or not at all.
• the hydraulic properties of a pump are only shown to advantage when the pump is fully filled with liquid and contains no air or gas.
• the present invention relates to a solution with which in simple manner the ideal effective liquid flow can always be found in the assembly, both during the pump action or the intake action via the valve, and whereby the pump in determined preferred embodiments can moreover be automatically vented.
• valve with variable opening between the assembly with the liquid circuit and the valve, with optionally a second connection to the suction side of the pump, between preferably a non-return valve and the pump, it has become possible to regulate the liquid flow in both directions with a standard pump without rotation speed control and a standard valve without an additional valve with choke function.
• pump with valve pump with valve
• Figure 1 shows a heating installation 24 with an expansion provision 1 in an embodiment according to the invention
• Figure 2 shows a heating installation 24 with conventional expansion provision 2
• Figure 3 shows an example relating to a circuit of valve 24 with variable passage in an embodiment according to the invention
• Figure 4 shows a detail of an alternative embodiment relative to that of figure 1;
• Figure 5 shows an additional embodiment relative to that of figure 4 ;
• Figure 6 shows an alternative embodiment relative to figure 1;
• Figures 7 and 8 show operating modes in separate operating situations of the expansion device in the heating system according to the invention;
• Figure 9 shows an additional alternative embodiment with some similarity to that of figure 6;
• Figure 1 shows how automatic pressure regulation takes place in hydraulic-mechanical manner in expansion device 1 according to the invention.
• a pressure sensor 11 transmits the system pressure in the assembly with liquid circuit 25 to a usually electronically controlled (not shown) control unit with which expansion device 1 is actuated. Because of temperature variations in the assembly with liquid circuit 25, the volume of the liquid present therein is subject to changes. An increase in the liquid volume will cause a pressure increase in the assembly with liquid circuit 25, and the reverse takes place when the liquid volume decreases.
• pump 4 and a valve 24 with variable passage, in particular controllable valve 5 in combination with valve 24, the liquid volume in liquid circuit 25, and consequently the system pressure therein, can be held almost constant, or at least constant within a predetermined bandwidth.
• Figure 3 shows the overall control of the pressure regulation.
• valve 5 is opened and simultaneously herewith valve 24 with variable passage is activated to the 'open' position (from the closed position) .
• the variable passage of valve 24 will always reciprocate in slowed manner from the closed position to the opened position, and vice versa.
• Particular use is made according to the present invention of this slowing effect (slow reciprocation between closed and open) , in addition to the possibility of fixedly holding any intermediate position.
• a time duration between the open and closed position of the variable passage of valve 24 can amount to as much as about 10 seconds or more, although a shorter time duration need not be a problem. In the case of a faster action valve the movement of the drive can after all be repeatedly interrupted.
• valve 24 with variable opening is opened slowly or is at least gradually opened increasingly further.
• the variable opening of valve 24 is activated (further) to the *open' position as soon as the first parallel line below the ideal pressure line is reached.
• Pump 4 is activated when the extreme (lower) limit value for the system pressure in the assembly with liquid circuit 24 has been reached.
• Valve 24 is also activated, with variable opening from fully open to the closed position.
• Figure 1 subsequently shows how the liquid can be circulated via connecting conduits 6 and 7 and the assembly with liquid circuit 25 without the installation pressure changing. This is possible because the variable opening of valve 24 is still situated in opened position. By making the variable passage of valve 24 smaller, the desired pressure increase in the system pressure in liquid circuit 25 is eventually reached or, if this takes place sooner, the desired system pressure. The variable opening of valve 24 remains in the position reached.
• FIG. 1 shows a liquid circuit 25 with a conventional expansion device 2 without the new valve with variable passage 24.
• FIG. 1 shows a liquid circuit 25 with a conventional expansion device 2 without the new valve with variable passage 24.
• a particular feature of expansion device 1 in figure 1 is that reservoir 3 is embodied without membrane 27 as utilized in the known configuration according to figure 2.
• the particular embodiment of expansion device 1 makes it possible to generate a below-atmospheric pressure at liquid levels in the lower part of reservoir 3, whereby degassing of the liquid can be effected very well .
• valve 24 can be embodied with a position recognition, whereby it is possible to pre-activate the desired passage to a desired position (from the control unit) . It is however also possible to apply a simple drive without position indication for valve 24 with variable passage. In this case the control unit (not shown) measures the speed or liquid flow and adjusts the variable passage of valve 24 thereto.
• valve 5 When a valve 5 with a greater capacity than required is applied in pump 4, it is readily possible using the variable passage of valve 24 to operate a large operating range of smaller heating or cooling systems, such as liquid circuit 25, using a standard version of expansion device 1.
• a further important advantage of the invention relates to setting of expansion device 1 of figure 1 into operation.
• the assembly with liquid circuit 25 and expansion device 1 will - even after being fully filled with liquid - possibly contain enclosed quantities of gas at vital parts such as a pump 4, and therefore be unable to function.
• a pump 4 be vented and fully filled with water without manual intervention being necessary.
• valve 24 By holding valve 24 with variable passage in fully opened position it is necessary to wait a short time to vent enclosed gases via vent 19, for instance a float vent associated with pump 4, and to then start pump 4.
• This pump 4 can now circulate water substantially without pressure difference via connecting conduits 6 and 7 and liquid circuit 25 until all enclosed gases have been removed. Once filled with liquid, pump 4 is fully operational.
• check valve 28 is further arranged between valve 24 with variable passage, in particular (as shown more clearly in figure 4) a motor valve 24, and pump 4.
• check valve 28 serves, during intake of water from assembly 25 to expansion tank 3, to prevent water flowing in opposite direction through pump 4, this being undesirable.
• expansion device 30 according to figure 4 further differs from that of figure 1 in that check valve 28 with the whole connection between motor valve 24 and the suction side of pump 4 is removed. Many of the advantages intended with the device can then still be realized.
• the expansion device 31 differs again from that of figures 1 and 4 in that a pressure-regulated valve 29 is arranged, in particular parallel to valve 24 with variable and preferably also adjustable passage and to the usual valve 5 or shutter for intake of liquid from assembly 25.
• a pressure-regulated valve 29 is arranged, in particular parallel to valve 24 with variable and preferably also adjustable passage and to the usual valve 5 or shutter for intake of liquid from assembly 25.
• An additional overpressure safety can hereby be realized, wherein the pressure-regulated safety valve 29 is opened at a fixed preset pressure value in assembly 25 with liquid circuit 25 in order to admit liquid from the assembly to expansion device 31, and in particular expansion tank 3 (not shown in figure 5).
• a connection can also be arranged from motor valve 24 to the suction side of pump 4, as in the configuration according to figure 1.
• the embodiment of figure 6 differs from the foregoing embodiments in that pump 4 is incorporated in a pump unit 32 having therein motor valve 4, non-return valves 12, 28 and the driven valve 5.
• a temperature sensor 33 is moreover arranged in the same pump unit.
• a compact configuration of the whole expansion device 34 can be realized by providing these elements in a combined unit 32.
• a measuring sensor 10 measures the weight of the whole expansion tank 3. By determining the weight of the expansion tank beforehand, i.e. without it being filled with heat transfer liquid, the amount of water (liquid) in expansion tank 3 can be derived in simple manner on the basis of the change in weight of expansion tank 3 with water therein. The filling level can thus also be derived, this in relation to the volume of expansion tank 3.
• a further pressure sensor 35 is herein arranged which measures the pressure in the gas part of expansion tank 3.
• Two valves are arranged here in combination with pressure sensor 35. These two valves 36,37 serve to draw in air or to allow escape of air subject to a pressure recorded by pressure sensor 35. The operation is as follows.
• air can be drawn in via valve 36 in the case of a fall in the pressure in the expansion tank of for instance 0.3 bar.
• second valve 37 is opened to allow this excess to escape.
• Such a higher pressure in the gas in the expansion tank is for instance the result of an increase in the expansion liquid in expansion tank 3.
• Air or gas at atmospheric pressure can thus be blown off.
• An operating pressure in expansion tank 3 lies here between -0.3 and 0 bar relative to the atmospheric pressure. A considerable improvement can thus be provided for the purpose of degassing of heat transfer liquid. This is because an additional method can thus be provided for degassing the heat transfer fluid in expansion tank 3 relative to the already provided option with float valve 22.
• the embodiment of 40 of figure 9 shows a strong resemblance to the embodiment of figure 6, but differs therefrom in respect of the following aspects and features.
• a pressure sensor 41 measures the pressure in the water section in expansion tank 3, 26 from a lowest point.
• a second pressure sensor 38 measures the pressure in a liquid column 39, the end of which extends into the centre of expansion tank 3, 26. Because water from liquid circuit 25 flows into expansion tank 3, 26 via liquid column 39 at each intake, column 39 continuously remains almost wholly filled with water. The liquid level or volume of the water in the water section in expansion tank 3, 26 will always vary in response to the temperature in liquid circuit 25.
• the liquid level is the same at the outflow end of liquid column 39, halfway along expansion tank 3, 26.
• the liquid level or the volume in the upper half of expansion tank 3, 26 can then be derived from historical measurement values relating to the lower half, and relates to liquid column 39 increased by the gas pressure.
• the liquid column can further be provided with measures to further enhance degasification, such as turbulence generating means for the purpose of further enhancing release of gases from the liquid.
• turbulence generating means can thus be formed by ratchet rings in liquid column 39.
• Typical of the measured pressure values in the upper part of expansion tank 3, 26 is that the pressures of both pressure sensors 41, 38 will always equal each other because the same liquid column with gas pressure is applicable.
• Valve 36 with which air can be drawn in, is in this embodiment a spring-loaded valve which opens in one direction at a pressure difference of preferably 0.3 bar, and remains closed in the opposite direction.
• Valve 37 along which air can escape, opens in one direction almost without pressure difference, and remains closed in an opposite direction.
• an excess of gas in expansion tank 3, 26 can result in opening of second valve 37 in order to allow this excess to escape.
• the just above-atmospheric pressure in the gas in the expansion tank is for instance the result of an increase in the expansion liquid in expansion tank 3, 26.
• Air or gas which has separated from the water as a result of the low pressure, and is situated in the water section of expansion tank 3, 26, can thus be blown off at atmospheric pressure via vent or float valve 22.
• an operating pressure in expansion tank 3 also lies here between -0.3 and 0 bar relative to atmospheric pressure as maintained in expansion tank 26 of figure 2. A considerable improvement can thus be provided for the purpose of degassing heat transfer liquid.
• valves 36, 37, as well as being controlled in mechanical manner as a spring-loaded embodiment, can also be controlled by a switching mechanism or control in interaction with the recorded pressure in expansion tank 3, 26.
• Figures 7 and 8 each show three situations demonstrating how unique the positioning of motor valve 24 is in combination with the other components of expansion device 1.
• the pump 40 in the embodiment of figure 9, as can be seen in the top view of figure 7, can always start substantially without pressure difference, it has become very simple to expel possible air inclusions in the pump. This is because the system pressure is available here at both the suction side and the pressure side of the pump, whereby the pump action, after switch-on, generates sufficient thrust to discharge via (float) vent 19 any air possibly still present in the pump housing.
• An additional great advantage is that the electricity supply can be used for feedback to the mains or to charge a battery with which the control system with a number of basic functions such as valve control can be powered.
• control system can have available a self-generated operating voltage, this provides, in addition to an energy-saving, a greater operational reliability, for instance in the case of (mains) power outage.
• a water dynamo 42 is also incorporated in figure 11.
• the functions and advantages of water dynamo 42 in figure 11 are the same as that of figure 10, with the difference that water dynamo 42 is not connected to the inlet of the pump. The pump cannot therefore be vented in the above described manner.
• a tube 43 is further arranged under vent 22 ⁇ embodied here with protection against return flow) on the expansion tank, relating to an embodiment with a membrane .
• Such a recorded position of motor valve 24 can be useful in respect of recording operating modes, subsequent monitoring, for instance after a breakdown, and normal operating modes.
• Such a recorded position can moreover be preset and utilized in a determined operating mode, at least if such an operating mode is detected by approximation. Fine adjustment relative to such a recorded value can then take place easily without an interactive process requiring different iterations in order to arrive at a desired setting of the motor valve. This contributes toward the simplicity and therefore elegance of the activation and the control and the monitoring of motor valve 24.

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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)
• Details Of Reciprocating Pumps (AREA)
• Steam Or Hot-Water Central Heating Systems (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Cites Families (13)

• 2008
  • 2008-11-28 NL NL1036252A patent/NL1036252C2/nl not_active IP Right Cessation
• 2009
  • 2009-04-22 EP EP09734468.3A patent/EP2281151B1/de active Active
  • 2009-04-22 WO PCT/NL2009/050215 patent/WO2009131450A2/en active Application Filing

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