DE19710905C1 - Room heating system operating method - Google Patents

Abstract

The operating method is for a system having a heating medium heater (12), a circulation pump (28) to feed radiators (14), and feed and return temperature sensors (20,22). The functional feed temperature is maintained constant or almost constant, at the set feed temperature level for the lowest ambient temperature, during the complete heating period, or at least for that part of the heating period, in which the return temperature is higher than a set minimum level. With rising ambient temperature, the return temperature is reduced until it reaches a set minimum level, and then remains constant. The heating medium volume is controlled by regulator (26), so that functional feed and return temperatures can adjust dependant upon ambient temperature, and the water heater is regulated to achieve the set feed temperature.

Description

Technical field

The present invention relates to a method for operating a heat exchanger Care system for rooms with a heat generator unit, which is an energy source is supplied and which heats a heating medium, at least one heating surface unit that supplies the heating medium from the heat generator unit via a flow fed and discharged via a return to the heat generator unit and which emits the heat, a pump unit that circulates the heating medium inside rolls, a temperature sensor for the flow temperature, a Temperatursen sensor for the return temperature, a temperature sensor for the ambient or Outside temperature and / or room temperature and a control unit, depending on the flow temperature, return temperature and vice versa temperature and / or room temperature that supplied to the heating surface unit Heat quantity controls / regulates, whereby the course of the flow temperature and the The course of the return temperature depends on the ambient temperature is laid.

State of the art

Known heat supply systems of the type mentioned are usually equipped with a control system that adjusts the heating medium temperature to the ambient temperature, the supply temperature being mostly used. The systems are operated at a low ambient temperature with a relatively high heating medium temperature. In Fig. 3, the relationship between the heating medium temperature ϑ _H and the ambient temperature ϑ _U is shown schematically in a diagram. The dashed lines apply to the course of the function, in each case for the flow 50 and the return 52 . At a design outside temperature of z. B. -12 ° C, the flow temperature is z. B. 75 ° C (= design flow temperature). This decreases from z. B. 20 ° C as soon as the ambient temperature has reached 20 ° C. The return temperature 52 is at z. B. -12 ° C ambient temperature z. B. 60 ° C (= design return temperature) and decreases like the flow temperature to + 20 ° C with the ambient temperature.

For some time now, heat generators have been gaining a lot in heating technology temperature-dependent efficiencies (e.g. condensing boilers, solar panels ren) increasingly important. In order to achieve a clear ver To achieve consumption reduction, however, the heating return temperature must be less than approx. 50 ° C.

For this reason, the heating medium temperatures are generally set very low when using such devices. An embodiment is shown in the diagram according to FIG. 3 with dash-dotted functional curves. The flow 54 begins at -12 ° C ambient temperature with the value of z. B. 50 ° C and takes up to the value of z. B. from 20 ° C at an outside temperature of 20 ° C. The return 56 begins at an outside temperature of -12 ° C with the value of z. B. 40 ° C and decreases to the same value as the flow 54 at 20 ° C outside temperature.

Due to the low temperatures, the heat generator can do well all year round Work efficiency, which significantly reduces consumption becomes.

The disadvantage is that due to the low heating medium temperature (flow and return temperature) drastically larger heating surfaces are required are used to supply the respective rooms with the required heat flow This means a significant increase in the price of the entire system.

Furthermore, the primary energy expenditure for the overall system is thereby unnecessary maneuverably increased so that the total energy saving at least is severely impaired. Added to this is the so-called radiant heating due to the large heating surface requirement mostly no longer be executed can. In their place, heating surfaces must be provided that have a high Share of convection, which in terms of the health of users of the Heat supply systems is not optimal.

In order to avoid the disadvantages mentioned, various proposals have been made makes. DE 43 12 808 proposes to increase the speed of the pump control that there is a largely constant difference between the lead and Set return temperature.

However, the potential of an optimal consumption reduction is not exhausted because the return temperature depends on the exercise temperature is still relatively high.

DE 43 34 664 uses a method for specifying the heating temperature suggested that the most cost-effective using system-specific values  Pairing volume flow and heating temperature for the respective reverse exercise temperature.

Here, however, the flow temperature is dependent on the Ambient temperature not specified, so that especially when using Condensing boilers with increasing ambient temperature, unwanted, high Flow temperatures that can be higher than the design flow temperatures NEN, occur. This has the consequence that heating surface temperatures during the heating period temperatures that can endanger users, and that a desirable specification of the heating temperatures depending cannot take place from the ambient temperature. Depending on the specification of the Ausle supply flow and return temperature must also the heating surface size, which is important for the total cost of the heating system, larger than necessary to get voted.

Finally, a method is proposed in DE 32 35 364, the difference of Maintain flow and return temperature at a specified setpoint, or in To change depending on the return temperature.

However, the course of the heating medium temperatures is not dependent on this speed of the ambient temperature, but depending on the load of the Heating system, influenced. The difference between the flow and return temperatures should be equal neither kept at a predetermined setpoint, or depending on the return temperature set in the heating network.

The difference between the flow and return temperatures is therefore not attempted to be kept as large as possible during the entire heating period, which means in particular especially when using heaters with temperature-dependent efficiencies not achieve the optimal mode of operation with the greatest possible efficiency becomes.

Presentation of the invention

The present invention has the technical problem or the object based on the prior art mentioned, the disadvantages shown to bypass and a method of operating a heat supply system to be specified, which ensures reliable and safe operation and at which has a low energy consumption.

The inventive method is characterized by the features of the independent An given 1. Advantageous design and further training are opposed the dependent claims.  

The inventive method is accordingly characterized in that the functionally predetermined spreading curve (difference between the lead temperature and the return temperature) depending on the environment exercise temperature or reaching a desired room temperature or the fulfillment of the heating task compared to the known predetermined chaff tion course is increased and that the maximum flow temperature of the Ausle supply flow temperature corresponds. The invention proceeds from the consideration that the mean heating surface temperature for the design of the heating surface size temperature (a suitable mean value from the flow and return temperature) is giving, while the level of efficiency of the heat generator in the we depends largely on the heating return temperature.

The fact that, according to the invention, the spread of the heating system (difference between flow and return temperature) is selected as large as possible, one Relatively high average heating surface temperature can be achieved while at the same time A relatively low return temperature depending on the ambient temperature rature, whereby the heat generator can work with high efficiency without that as a result the heating surfaces must be enlarged. It can also do that Room temperature can be recorded in order to fulfill the heating task, namely reaching and maintaining predetermined room temperatures, too controlled lieren.

A preferred embodiment of the method according to the invention is distinguished characterized in that the flow temperature is independent of the ambient temperature remains constant, whereby a preferred further training is characterized net that the set course of the flow temperature at least at low Ambient temperature is constant and the specified course of the return temperatures temperature as a function of the ambient temperature, at least at higher temperatures exercise temperature is constant.

This makes practical temperature ranges of the method according to the invention characterized in that the flow temperature in the area of low ambient temperatures tur in the range between 60 ° C and 95 ° C and the return temperature tur in the range of low ambient temperatures in the range between 50 ° C and 80 ° C and in the high ambient temperature range between 20 ° C and 25 ° C is set.

A functional technical implementation of the method according to the invention succeeds by influencing the heating medium flow depending from the ambient temperature, e.g. B. by changing the pumped pump volume flow or by more or less throttling the heating medium vo  lumen flow, e.g. B. via the thermostatic valves on the heating surfaces. Here will preferably a variable-speed pump unit is used in one embodiment, which is acted upon by the control unit.

In the case of power-controlled heating units, the heat supply is controlled in this way ert / regulated that the functionally specified flow temperature reaches becomes.

For heat generators with constant or only slightly variable The process can achieve heating power by interposing a buffer memory will be realized. Here, for. B. the pump between the storage and Heizflä Chen as well as the pump between the heat generator and the buffer storage in the rotation number can be influenced.

Further embodiments and advantages of the invention result from the Examples given below.

Brief description of the drawing

The invention and advantageous embodiments and developments thereof ben are based on the examples shown in the drawing described and explained in more detail. The ent to the description and the drawing Taking features can be used individually or in groups of any Combination can be applied according to the invention. Show it:

Fig. 1 shows a schematic block diagram of a heat supply system,

Fig. 2 shows a schematic diagram of the relationship between the course of the flow temperature and return temperature as a function of the ambient temperature and

Fig. 3 is a schematic diagram of the course of the flow temperature and return temperature as a function of the ambient temperature in known heat supply systems.

Ways of Carrying Out the Invention

A heat supply system 10 has a heat generating device 12 to which an energy carrier is supplied from the outside, which is symbolically represented in FIG. 1 by the arrow 60 .

The heat generating device 12 heats a heating medium which reaches the heating surface units 14 via a run 16 and is fed back to the heat generating device 12 via a return 18 . In the lead a temperature sensor 20 is present, which measures the temperature of the heating medium in the lead and emits corresponding signals to a control / regulating unit 26 . Likewise, a temperature sensor 22 is provided in the return line 18, which measures the temperature in the return line 18 and corresponding outputs signals to the control / regulating unit 26th Finally, there is also a temperature sensor 24 which measures the ambient temperature (outside temperature) and emits appropriate signals to the control unit 26 . In addition, the room temperature can be detected by a sensor 25 and the signals can be sent to the control unit 26 .

Depending on the signals from the temperature sensors 20 , 22 , 24 and possibly 25 , the control / regulating unit 26 regulates the heat generating device 12 and a pump unit 28 arranged in the flow or return.

A heating curve example according to which the heat supply system is operated is shown schematically in a diagram in FIG. 2. The course 40 of the flow temperature and the course 42 of the return temperature is designed such that there is a large spread S between the two courses and that the flow temperature and the return temperature are constant in two separate ambient temperature ranges. The diagram has an area 30 schematically indicated in FIG. 2 on the abscissa with relatively low ambient temperatures and constant flow temperatures and a wide area 34 with ambient temperatures up to 20 ° C., where the return temperature is constant.

The course 40 of the flow temperature begins at 90 ° C and remains in this range even with increasing ambient temperature. At higher ambient temperatures, the curve then drops to 20 ° C with a convex curvature.

The course 42 of the return temperature begins at 70 ° C at an ambient temperature of -12 ° C. It drops relatively quickly with a concave curvature to a temperature of just over 20 ° C in order to then remain constant. The dashed curve 41 represents the mean value between the flow 40 and the return 42 .

With the heating curves shown it is achieved on the one hand that the current flow temperature cannot exceed the specified design flow temperature, so that a risk from excessive heating medium temperatures is excluded and that the course 41 of the mean temperature ϑ _{H, center} of the flow and return temperature for large Areas kept relatively high who can, so that a high heating surface heat flow can be achieved. In addition, the return temperature is largely kept below 50 ° C, so that, for example, condensing boilers can be used, which then work with high efficiency. At the same time, heating surfaces can be used, which emit most of the heat through radiation, which is very pleasant for the users of the heat supply system. An enlargement of the heating surface as in the known systems in low temperature operation is not necessary.

With the illustrated method for operating a heat supply system operation with low fuel consumption is possible. At the same time it will enables the same amount of heat to be available with a smaller heating surface to deliver. This reduces the primary energy and costs for the Overall system clear.

Claims (5)

1. Method for operating a heat supply system for rooms with

• - A heat generator unit ( 12 ), which is supplied with an energy source and which heats a heating medium,
• at least one heating surface unit ( 14 ) which is supplied with the heating medium from the heat generator unit ( 12 ) via a flow ( 16 ) and is discharged via a return line ( 18 ) to the heat generator unit ( 12 ) and which emits the heat,
• - a circulation pump ( 28 ) which transports the heating medium,
• - a temperature sensor ( 20 ) for the flow temperature (ϑ _{H, V} ),
• - a temperature sensor ( 22 ) for the return temperature (ϑ _{H, R} ),
• - A temperature sensor ( 24 ) for the ambient or outside temperature (ϑ _U ) and / or ( 25 ) for the respective room temperature (ϑ _R ) and
• - A control unit ( 26 ) which, depending on the flow temperature (ϑ _{H, V} ), return temperature (ϑ _{H, R} ), possibly ambient temperature (ϑ _U ) and / or room temperature (ϑ _R ), corresponds to the heating surface unit ( 14 ) The amount of heat supplied controls the flow temperature (ϑ _{H, V} ) and the return temperature (ϑ _{H, R} ) depending on the ambient temperature (ϑ _U ) or room temperature (ϑ _R ) ,
• - characterized in that the functionally predetermined Vorlauftempe temperature during the entire heating period or at least for the part of the heating period in which the return temperature is greater than a predetermined minimum value, is kept constant or approximately constant on the design flow temperature defined at the lowest ambient temperature and the Return temperature decreases with increasing ambient temperature until it reaches a predetermined minimum value and from this also remains constant, whereby the circulating mass of the heating medium is regulated by the control unit ( 26 ) so that the functionally predetermined temperatures depend on the flow and return can adjust from the ambient temperature and the heat generator unit is controlled so that the given flow temperature is reached.

2. The method according to claim 1, characterized in that the conveyed volume flow of the circulation pump functionally specified depending on the ambient temperature and is set by a control unit. 3. The method according to claim 1, characterized in that the difference generated by the circulation pump pressure depending on the ambient temperature ben and is set by a control unit. 4. The method according to claim 1, characterized in that the set return temperature, or temporal change of the same, or the room temperature, or their temporal changes change, from a control unit as a measure of the adjustment and setting volume flow is used. 5. The method according to claim 1, characterized in that

• a buffer storage unit is used between the heat generator unit and the heating surface unit,
• the heating medium is transported from the heat generation unit to the buffer storage unit by means of a pump unit and this is regulated in such a way that the functionally predetermined flow temperature is reached as a function of the ambient temperature,
• - In the flow or return between the buffer storage unit and Heizflächenein unit, a pump unit with variable speed is used, which is acted upon by the control unit.