DE102018110439A1 - thermostatic head - Google Patents

Abstract

The invention relates to a thermostatic head for adjusting a radiator. According to the invention it is proposed that the thermostatic head cooperates with a first temperature sensor which detects the temperature in the flow of the radiator, that the thermostatic head cooperates with a second temperature sensor which detects the temperature in the return of the radiator, and that the thermostatic head an adjusting means for a Having valve in the flow or return of the radiator, with which adjusting means the flow rate of the heating medium through the radiator in dependence on the detected temperatures in the flow and return is adjustable.

Description

The invention relates to a thermostatic head for adjusting a radiator. Such thermostatic heads are known in a variety of embodiments and generally require no further explanation.

In general, the thermostatic heads cooperate with a radiator valve, which is mounted in the flow or in the return of a radiator in the heating system. The valve is opened or closed by a plunger with a valve plate, which is moved by the thermostat. The plunger can be actuated by an expanding liquid, by a bimetal or else by electrical or electronic adjusting means. The various embodiments are also known and therefore need no further explanation.

The thermostat head detects the room temperature and adjusts the valve accordingly. Often, however, a desired absolute value is not adjustable, but the thermostatic head is adjusted according to the well-being of the persons in the room to be heated. Then the thermostatic head keeps the room at this set temperature.

The thermostatic head regulates the flow of the heating medium through the radiator assigned to it and thus keeps the room temperature at the desired value. It is known for the energy-saving adjustment of heating systems and necessary to carry out a hydraulic balancing. In a hydraulic balancing the individual static heating surfaces or heating circuits of radiators or their presettable valves are adjusted so that at a predetermined flow temperature each room the required amount of heat is supplied to obtain the desired room temperature. For this purpose, the thermostatic head is adjusted so that the required flow of the heating medium, for. B. heating water, with the specified flow temperature provides the required amount of heat. This makes it possible, among other things, to promote the desired amount of heat into the rooms even at lower flow temperatures. The hydraulic adjustment in detail is basically known and therefore needs no further explanation.

It can be considerably reduced by a hydraulic balancing a heating system, the energy consumption and thus the heating costs. For this purpose, however, it is necessary that the radiators of the rooms to be heated are continuously flowed through with the lowest possible flow temperature and the lowest possible flow rate. Then the heating system can be operated energy-efficiently and optimally. Furthermore, it should be achieved that the return temperatures of the radiator are at the lowest possible and uniform level, so that the boiler does not clock, so jump on and go out, must. Furthermore, gas condensing boilers can really use the heat from the exhaust gas (condensing operation at return temperatures below approx. 55 ° C).

However, hydraulic balancing requires special valves that allow hydraulic balancing. These valves are set during heating commissioning according to the heat demand for each room. In older heating systems, the mounted valves are often not suitable for hydraulic balancing, so they need to be replaced. This is associated with increased staff and cost and longer downtime especially in large housing estates or tenements.

Furthermore, the valve setting values often have to be determined and calculated costly by including the pipe network system, the heat requirement and the room sizes.

The invention has the object of providing a thermostatic head in such a way that a hydraulic adjustment can be done without changing the valves or the calculation of the hydraulic balance.

The object is achieved according to the invention in that the thermostatic head cooperates with a first temperature sensor, which detects the temperature in the flow of the radiator, that the thermostatic head interacts with a second temperature sensor, which detects the temperature in the return of the radiator, and that the thermostatic head a Having adjusting means for a valve in the flow or return of the radiator, with which adjusting means the flow rate of the heating medium through the radiator in dependence on the detected temperatures in the flow and return is adjustable. The invention makes use of the fact that on the one hand the heat demand for maintaining the temperature in a room is known or can be determined. This heat demand Q must be supplied via the heating medium: $$\text{dQ}/\text{dt}=\text{dm}/\text{dt}\cdot \text{c}\cdot \left({\text{T}}_{\text{VL}}-{\text{T}}_{\text{RL}}\right)$$

With dm / dt = mass flow of the heating medium, t = time, c = specific heat capacity of the heating medium, T _VL = flow temperature and T _RL = return temperature. The required volume flow (dV / dt = (dm / dt) / ρ with ρ = density of the heating medium) for a certain amount of heat results from the temperature difference between flow and return.

By detecting the flow temperature and the return temperature at the radiator, it is possible to directly influence the heat released. If the temperature difference between flow and return is too high, too little heating medium flows through the radiator, and the return temperature is too low, starting from a set flow temperature. The result is that the heating burner clocks more often because the volume flow through the boiler is too low and a shortage of space occurs. If the difference is too low, the return temperature is too high. The consequence is a failure or reduction of the Gasbrennwerteffektes and a cyclic operation of the boiler by an excessive flow through the boiler. Both leads to an undersupply of radiators located further away radiator or flow noise in the radiators.

By specifying a temperature difference between flow and return to the hydraulic balancing the valve can be adjusted accordingly so that the required volume flow for the required heat demand flows through the radiator. It is not necessary to replace the valve itself but only the thermostatic head with the required temperature sensors. Longer downtimes and longer installation work on the heating system are therefore eliminated. By the thermostatic head according to the invention, the non-presettable heating valve is adjusted as if it had been adjusted by a hydraulic balance.

The temperature sensor on the flow can be arranged in a simple manner on the thermostatic head and, for example, tap the flow temperature via the valve stem, which has at least approximately the temperature as the flow. The same applies if the valve is arranged in the return. The temperature sensor on the return can detect the temperature at the radiator outlet. The installation of this sensor from the outside of the return pipe is easily possible via thermal paste and a contact probe and a corresponding clamp.

Furthermore, it can be provided that the thermostatic head interacts with a third temperature sensor which detects the room temperature. It is expedient if the thermostatic head is adjustable to a desired room temperature. This setpoint temperature can be set by changing the temperature difference, so that the valve is opened further for a higher set room temperature.

This type of temperature control can be done particularly well with an electronic thermostatic head, as it can be readily equipped with the corresponding measurement signal inputs. It is therefore provided according to the invention that the adjusting means comprises an electric actuator, for example a servomotor, which is controlled by an electronic control to adjust the valve in dependence on the detected temperatures. The actuating means thus comprises measuring signal inputs for the flow temperature, the return temperature and, if appropriate, for the room temperature. From these values, the volume flow of the heating medium to be set by the radiator and thus the valve tappet position can be determined and adjusted. Finally, the valve stem is opened or closed until the return temperature for the required amount of heat for the desired room temperature is established.

It is useful if at least one temperature sensor works electronically and that the temperature sensor is connected to the return with a signal cable to the thermostat head on the flow or that the temperature sensor is connected to the flow with a signal cable to the thermostatic head on the return. The signal cable can easily be concealed behind an already mounted radiator and thus does not disturb the visual appearance. For new radiators can be provided that the signal cable runs within the Heizköpergehäuses. Then the temperature sensor on the return (or flow) can be pre-assembled, so that no additional installation is visible from the outside.

It can also be provided that at least one temperature sensor operates electronically and that the temperature sensor cooperates via a radio link with the thermostatic head. The energy supply required for this purpose can be done by batteries, which are exchanged during maintenance intervals, for example when reading the amount of heat consumed. In particular, replacement of the batteries at the radio transmitter can be performed when the batteries on the electronic thermostatic head are replaced.

The actuating means actuate the valve as a function of the temperature difference between the detected flow temperature, the detected return temperature and the room temperature. It is expedient if the actuating means keeps the temperature difference between the detected flow temperature and return temperature to an adjustable constant value. Then the heating system can always run in an optimized working area, so that the energy consumption is reduced.

The thermostatic head according to the invention eliminates the need for a presettable valve for hydraulic balancing. The limitation of the volume flow of the heating medium to Delivery of the required or desired amount of heat is done rather by the built-in conventional valve. In that case, it may happen that the valves are always in a partially closed state, in particular in the case of the radiators located further up the heating line. The flow channel is therefore relatively narrow and can easily clog. According to the invention, it is therefore provided that the electronic control activates a cleaning function such that the actuating means completely opens the valve in predeterminable time intervals for a predeterminable time. Then, the radiator for a short time, for example, applied for five to ten minutes with a high flow, be solved by the dirt particles in the valve seat and removed.

Above, the invention has been described with reference to an electronic thermostatic head. But it can also be equipped mechanically or hydraulically working thermostatic heads accordingly. Then it is provided that at least one temperature sensor has a heat-expanding liquid, and that the temperature sensor is connected to the return or flow via a capillary with the thermostatic head at the supply or at the return. The liquid of the remote temperature sensor works together with the other temperature sensor and, if necessary, with the room temperature sensor to the valve position, so that sets the same effect.

The invention will be explained in more detail below with reference to the schematic drawing. The single FIGURE shows a radiator with the thermostatic head according to the invention.

The radiator shown in the drawing 11 is traversed in a known manner by a heating medium, for example water, from the flow VL to the return RL. The radiator gives heat to the room 12 from where the radiator is mounted. The flow rate of the heating medium through the radiator 11 is over a valve 13 adjustable, via a thermostatic head 14 is set. For a higher room temperature, the thermostatic head 14 further turned up, so that the valve 13 opens and more heating medium the radiator 11 flows through. The room is supplied with more heat energy so that it gets warmer.

For a lower temperature, the thermostatic head 14 turned off, so that the valve 13 further closes and the flow rate of the heating medium through the radiator 11 gets smaller. The room 12 less heat energy is supplied so that the room temperature drops.

For a favorable operation of the heating system to which the radiator or underfloor heating is connected, it is expedient to carry out a hydraulic adjustment, by which the flow rate of the heating medium through the radiator to produce a predeterminable room temperature as a function of the flow temperature T _VL is preset. The default causes the radiator 11 flows through with a predetermined amount of heating medium, so that a predetermined amount of heat is emitted. For this purpose, presettable valves on the radiator are needed, which are often not available and must be retrofitted. This creates an increased installation effort.

The thermostatic head shown in the drawing 14 is designed as an electronic thermostatic head and includes an electronic control 15 with which an actuating means or an actuator, for example a servomotor 16 is controlled to the valve 13 over a pestle 17 or to operate a spindle. The control 15 captures the flow temperature for this purpose T _VL in the flow VL and the return temperature TRL in the return of the radiator 11 , The valve 13 is by the servomotor 16 depending on the temperature difference T _VL - T _RL adjusted to increase or decrease the flow rate of the heating medium through the radiator so as to maintain the temperature spread at a preset value.

oder $$\text{dQ}/\text{dt}=\text{dV}/\text{dt}\cdot \text{c}/\mathrm{\rho }\cdot \left({\text{T}}_{\text{VL}}-{\text{T}}_{\text{RL}}\right)$$

ab. Die Wärmemenge kann daher durch das Erfassen der Vorlauf- und der Rücklauftemperatur unmittelbar eingestellt werden.The for the radiator 11 in the context of the hydraulic balancing amount of heat to be delivered depends on the temperature difference according to the equation $$\text{dQ}/\text{dt}=\text{dm}/\text{dt}\cdot \text{c}\cdot \left({\text{T}}_{\text{VL}}-{\text{T}}_{\text{RL}}\right)$$

or $$\text{dQ}/\text{dt}=\text{dV}/\text{dt}\cdot \text{c}/\mathrm{\rho }\cdot \left({\text{T}}_{\text{VL}}-{\text{T}}_{\text{RL}}\right)$$

from. The amount of heat can therefore be adjusted directly by detecting the flow and the return temperature.

The flow temperature T _VL can through a temperature sensor 18 in the lead VL be recorded. The temperature sensor can also be arranged in the thermostatic head and the temperature on the plunger 17 tapping, since this in the metallic and thus thermally conductive contact with the valve body in the valve 13 stands, which has the flow temperature.

The return temperature TRL is through a temperature sensor 19 detected, which is arranged or mounted in or on the return of the radiator. This can be done by a clamp, by which the temperature sensor is attached to the return heat-conducting. The power supply for the temperature sensor and the signal line for control 15 can via a signal cable 20 carried out in the radiator housing or behind the radiator 11 runs.

Both thus detected temperature signals are used as input for the electronic control 15 used. It can still be a room sensor 21 be provided, which detects the room temperature. The room temperature is also an input for the electronic control 15 ,

The servomotor 16 becomes dependent on the determined temperature difference T _VL - T _RL and the room temperature is controlled to the valve 13 to open or close. The room temperature can be used as a default for the temperature difference to be maintained. It is thus possible to supply the required amount of heat regardless of the flow temperature to a room, without a presettable valve is required. Rather, the adjustment of the volume flow of the heating medium by the conventional valve itself.

Claims (11)

Thermostatic head for adjusting a radiator (11), characterized in that the thermostatic head (14) cooperates with a first temperature sensor (18) which detects the temperature in the flow (VL) of the radiator (11) that the thermostatic head (14) with a second temperature sensor (19) cooperating, which detects the temperature in the return (RL) of the radiator (11), and that the thermostatic head (14) an adjusting means (16) for a valve (13) in the flow (VL) or return (RL) of the radiator (11), with which adjusting means (16) the flow rate of the heating medium through the radiator (11) in dependence on the detected temperatures in the flow (VL) and in the return (RL) is adjustable. Thermostatic head after Claim 1 , characterized in that the thermostatic head (14) cooperates with a third temperature sensor (21) which detects the room temperature. Thermostatic head after Claim 1 or 2 , characterized in that the thermostatic head (14) is adjustable to a desired room temperature. Thermostatic head according to one of the Claims 1 to 3 characterized in that the adjusting means (16) comprises an electric servomotor controlled by an electronic control (15) to adjust the valve (14) in dependence on the detected temperatures. Thermostatic head according to one of the Claims 1 to 3 , characterized in that at least one temperature sensor (18, 19, 21) operates electronically and that the temperature sensor (19) is connected at the return (RL) with a signal cable (20) to the thermostatic head (14) at the flow (VL) or the temperature sensor on the supply line is connected to the thermostat head on the return line with a signal cable. Thermostatic head after Claim 5 , characterized in that the signal cable extends within the Heizköpergehäuses. Thermostatic head after Claim 4 , characterized in that at least one temperature sensor operates electronically and that the temperature sensor cooperate via a radio link with the thermostatic head. Thermostatic head according to one of the Claims 1 to 7 , characterized in that the adjusting means (16) actuate the valve in dependence on the temperature difference between the detected flow temperature and the detected return temperature. Thermostatic head after Claim 8 , characterized in that adjusting means keeps the temperature difference between the detected flow temperature and return temperature to an adjustable constant value. Thermostatic head after Claim 4 , characterized in that the electronic control controls a cleaning function such that the actuating means completely opens the valve in predeterminable time intervals for a predeterminable time. Thermostatic head according to one of the Claims 1 to 3 , characterized in that at least one temperature sensor has a heat-expanding liquid, and that the temperature sensor is connected to the return or flow via a capillary tube with the thermostatic head on the flow or on the return.

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