AT513311A1 - heating system - Google Patents

Abstract

Heating system for supplying at least one consumer (3, 13), comprising a heating boiler (1) having a boiler feed connection (1a) and a boiler return connection (1b), and a buffer memory (2) having an upper connection (2a) and a lower terminal (2b). A return line (16) connects the lower port (2b) of the buffer reservoir (2), the boiler return port (1b) and the consumer (3, 13) with each other. A four-way mixing valve (4, 14) has a consumer port (4a, 14a), a boiler port (4b, 14b), a buffer port (4c, 14c), and a return port (4d, 14d). The four-way mixing valve (4, 14) connects the load port (4a, 14a) either with the boiler connection (4b, 14b) or with the buffer connection (4c, 14c) and mixes the heat transfer medium from the return line (16) via the return connection (4d , 14d) too.

Description

1 16152

The invention relates to a method for operating a heating system with a boiler and a buffer storage, in which optionally from a boiler flow connection of a boiler or an upper port of a buffer heat transfer medium is supplied to a consumer and via a return line to a boiler return port of the boiler or a lower port of a buffer is returned.

Heating systems are increasingly being equipped with buffer tanks. This is systemically necessary for wood solid fuel boilers, but also allows for other types of fuel, the integration of alternative energy sources such as solar energy or facilitates the domestic water.

The advantages of charging the buffer storage by the boiler are that the energy available in the storage tank can be better utilized even if, for example, the temperature level is insufficient to prepare service water or operate the heating system. In this way it is possible to raise the temperature level in the buffer memory to the required level. A disadvantage of such a system is that the heating buffer is always lossy. During the heating season, these losses are primarily compensated by the boiler. As a result, the fuel consumption is increased and the system efficiency is reduced accordingly. In addition, the solar yield can be reduced because the volume that is heated by the automatic boiler is no longer available to the solar system.

From AT 6 833 U a method for operating a heating system with a buffer memory is known in which a mixing valve is used to control the temperature distribution and in particular to avoid harmful condensation phenomena in the boiler. However, the disadvantages described above can not be significantly reduced thereby.

Object of the present invention is to provide a method and a boiler, so that the above disadvantages are avoided and energy losses are largely minimized. 2/18 2

The essential aspect of the present invention is that is supplied by the mixing valve, the consumer either via a first heat rail or a third heat rail. The first heat rail while the line network between the boiler flow and the mixing valve is called, while the third heat rail, the line network between the upper port of the buffer and the mixing valve is called. In addition, a line network is provided as the second heat rail, which is arranged between the boiler return port, the lower port of the buffer reservoir and the consumer return port and also has a connection to the mixing valve. The mixing valve can thus not only provide in a conventional manner, the appropriate target temperature for the consumer by a variable proportion of cold heat transfer medium from the second heat rail is mixed, but also regulate the different operating modes depending on the heat supply in the buffer memory.

According to the invention, these objects are achieved in that the consumer is supplied via a mixing valve which selectively delivers a mixture of heat transfer medium from the boiler flow connection and the return line or a mixture of heat transfer medium from the upper port of a buffer and the return line to the consumer.

An important aspect of the invention is that the heating operation via the boiler can be largely decoupled from the buffer memory, so that it is possible, for example in the lack of solar energy, to completely empty the buffer memory thermally. It is preferred in this case if the mixing valve interrupts either the connection to the boiler flow connection of the boiler or to the upper connection of the buffer memory in each operating state. Thus, a complete decoupling can be achieved.

Preferably, the mixing valve is also fed via a consumer return connection with heat transfer medium. As already stated above, the functionality of the temperature control at the load can be taken over by the mixing valve.

In particular, it is advantageous if the method is operated so that when a consumer target temperature is below a buffer storage temperature at the upper port of the buffer, the boiler is turned off and over 3/18 3, the mixing valve prevents the connection to the boiler flow connection and the consumer target temperature is controlled by mixing hot heat transfer medium from the upper port of the buffer and cold heat transfer medium from the consumer return port.

On the other hand, the method is operated so that when a consumer target temperature is above a buffer storage temperature at the top of the buffer, the boiler is turned on and the connection to the boiler flow connection is opened via the mixing valve and the consumer set temperature by mixing hot Heat transfer medium from the boiler flow connection and is controlled by a cold heat transfer medium from the return line to the consumer.

In this way, the respective operating situations can be taken into account in an efficient manner.

A particular advantage of the present method is that it is possible to optimally supply different consumers. Thus, for example, floor or Deckenheizkreise and Radiatorheizkreise and optionally external heat exchanger for domestic water can be supplied with the respectively required for them and optimum temperature level, without affecting the overall efficiency of the system. This is inventively achieved in that the individual consumers each have their own mixing valve is assigned.

A particularly favored embodiment variant of the method according to the invention is provided if, via a follow-up extension section, optionally heat transfer medium is conveyed from the boiler flow connection to the upper connection of the buffer store. The overrun extension section serves to allow charging of the buffer by the boiler specifically to achieve optimum operation here, if at low heat demand efficient operation of the boiler is not possible and at most too frequent switching on and off should be feared, then can be achieved in this way by using the buffer memory, an improvement in plant efficiency.

Furthermore, the present invention relates to a heating system for supplying at least one consumer, with a boiler, a 4/18 4

Boiler feed connection and a boiler return port, and with a buffer memory having an upper port and a lower port, wherein the boiler flow connection of the boiler is connected to a mixing valve, which communicates with a consumer. According to the invention, this heating system is characterized in that the mixing valve continues to communicate with both the upper port of the buffer reservoir and a return line connecting the lower port of the buffer reservoir, the boiler return port and a consumer.

In particular, the mixing valve is designed to mix a variable flow rate of the heat transfer medium from the return line to a consumer supplied flow rate. The mixing valve is also preferably designed to selectively interrupt the connection to the boiler supply connection or to the upper connection of the buffer storage.

The invention also relates to a mixing valve, which can be used for a heating system of the type described above, having a consumer connection, a boiler connection, a buffer connection and a return connection, wherein the consumer connection is in a variable relationship with another connection and with the return connection, wherein the additional connection is either the boiler connection or the buffer connection. The variable ratio is adjusted as usual in mixing valves by appropriate cross-sectional ratios. The mixing valve can be designed as an actual valve, ie seat valve, as a cock, as a slide, as a piston-cylinder arrangement or as a composite component of several components.

As a result, the present invention will be explained in more detail with reference to the embodiments illustrated in FIGS.

1 is a circuit diagram of a first embodiment of the invention, and FIG. 2 is a circuit diagram of an alternative embodiment of the invention.

In the embodiment 1, a heating system with a boiler 1, a buffer memory 2, a first consumer 3, a second consumer 13, a first mixing valve 4 and a second mixing valve 14 is shown. The boiler 1 5/18 5 provides in operation at a boiler flow connection la hot heat transfer medium available. About the first heat rail LI this heat transfer medium is fed to the mixing valves 4, 14 and fed to a boiler connection 4b and 14b. The mixing valves 4, 14 provide this heat transfer medium either to consumer connections 4a and 14a available, which are connected to consumer lines L4 and L14, in each of which a heating pump 5 or 15 is provided to supply the consumers 3, 13 with hot heat transfer medium , Of the consumers 3, 13, the heat transfer medium continues to flow in a return system with return lines 16, which is referred to here as the second heat rail L2. Depending on the hydraulic conditions, this second heat rail L2 leads the heat transfer medium to a boiler return connection 1b or to a lower connection 2b of the buffer store 2. In addition, the second heat rail L2 is also connected to a return connection 4d or 14d of the mixing valves 4, 14.

A third heat rail L3 in each case connects a buffer connection 4c, 14c of the mixing valves 4, 14 to an upper connection 2a of the buffer memory 2.

The heating system of Fig. 2 corresponds largely to that of Fig. 1 with the difference that at the boiler flow connection la additionally a follower extension section L3a branches, which is part of the third heat rail L3. In this follower extension section 3a, which thus establishes a direct connection between the boiler flow connection la and the upper connection 2a of the buffer memory 2, a follower pump 6 is provided.

As a result, the operation of the heating system according to the invention will be explained.

In principle, a distinction must be made between an operating state in which the temperature in the buffer store is sufficient to supply a consumer 3, 13 and an operating state in which this is not the case. Subsequently, a distinction must be made between a large heat demand and a low heat requirement.

By way of example, individual operating states for a consumer are explained on the basis of the different boundary conditions. It should be noted that due to the particular embodiment of the invention different operating conditions may occur for different consumers. 6/18 6

In the following examples, it is assumed without restriction of the general public of a boiler with 15 kW of power, which can be modulated up to a partial load of 30%. a. ^ Buffer storage loaded, large heat demand at the consumer

It is assumed that the consumer 3 heat transfer medium with a target temperature of 60 ° C should be provided. In the buffer memory 2 is located in the region of the upper port 2 a heat transfer medium with a temperature of 80 ° C before. The temperature in the return system (second heat rail L2) is 40 ° C.

In order to meet the heat demand of, for example, 12 kW of the consumer 3, a flow of about 516 l / h must be led to the consumer when a heat capacity of the heat transfer medium of 1.162 kW / kgK assumes .. This flow rate of 516 l / h at a temperature of 60 ° C is provided in the mixing valve by mixing a flow rate of 258 l / h at 80 ° C via the third heat rail L3 and a flow rate of 258 l / h via the second heat rail L2. The boiler 1 is in this case completely decoupled from the hydraulic system and out of service. b. ^ Buffer storage charged, small heat demand at the consumer

The temperature levels are analogous to the above example a.), It is only assumed that the consumer 3 is given a heat demand of 5 kW. This is supplied via a flow 215 l / h in the load line L4, which is provided in each case half of the third heat rail L3 and the second heat rail L2. c. ^ Buffer discharge, high heat demand at the consumer

Here it is assumed that the temperature of the heating medium in the buffer tank 2 is consistently 40 ° C. Thus, the target temperature at the consumer 3 can not be achieved by the buffer memory 2. In this case, the boiler 1 provides heat transfer medium with a temperature of 80 ° C in the first heat rail LI and indeed with a flow rate of 258 l / h. In the mixing valve 4, a further flow rate of 258 l / h from the second heat rail L2 with a temperature of 7/18 7 40 ° C is added, so that the consumer 3 a flow rate of 516 l / h with a temperature of 60 ° C to Is made available. d. ^ Buffer discharge, small heat demand at the consumer

Again, the temperature levels are analogous to the above example c.). It is merely the consumer a flow 215 l / h made available, which in turn consists of half of a heat flow from the first heat rail LI and from the second heat rail L2.

In the case of an automatic boiler, by way of derogation, the boiler temperature, which is the reference variable for the modulation, is lowered to 60 ° C and the flow rate is correspondingly increased by controlling the mixing valve. e. ^ Different heating circuits with different

Temperaturanforderunaen

The above examples c.) And d.) Can be varied, for example, insofar as in addition to the consumer 3 with a target temperature of 60 ° C another consumer 13, for example a floor heating circuit, with a set temperature of 35 ° C is present. In this case, the first consumer 3 is operated by the boiler 1 as in Examples c.) And d.), While the second consumer 13 in Examples a.) And b.) Is supplied by the buffer memory 2. f. 1 operation according to Fia. 2 with maturity extension

In order to operate the boiler regardless of the current heat demand in an optimal operating point and to avoid frequent switching on and off of the boiler with low heat demand, a follower extension can be provided, as shown in FIG. In this case, the excess heat of the boiler is used to charge the buffer tank 2 via the boiler 1, in which case the follower pump 6 is turned on, which feeds hot heat transfer medium from the boiler inlet connection la into the third heat rail L3. As a result, the buffer tank 2 flows through from top to bottom and is "charged" with a hot heat transfer medium. 8/18 8

The present invention makes it possible to represent with simple means in an energy-efficient manner different operating states of heating systems and to use energy optimally. 9.18

Claims (17)

9 PATENT REQUIREMENTS 1. Method for operating a heating system with a boiler and a buffer storage, in which optionally from a boiler flow connection (la) of a boiler (1) or an upper terminal (2a) of a buffer storage (2) heat transfer medium to a consumer (3, 13) supplied is returned via a return line (16) to a boiler return port (lb) of the boiler (1) or a lower port (2b) of a buffer memory (2), characterized in that the consumer (3, 13) via a mixing valve (4 , 14), which is optionally a mixture of heat transfer medium from the boiler flow connection (la) and the return line (16) or a mixture of heat transfer medium from the upper port (2a) of a buffer memory (2) and from the return line (16) to the consumer (3 , 13). 2. The method according to claim 1, characterized in that the mixing valve (4, 14) in each operating state either the connection to the boiler flow connection (la) of the boiler (1) or to the upper port (2a) of the buffer memory (2) interrupts. 3. The method according to claim 1 or 2, characterized in that when a consumer target temperature is below a buffer storage temperature at the upper port of the buffer memory (2), the boiler (1) is switched off and via the mixing valve (4, 14 ) the connection to the boiler flow connection (la) is suppressed and the consumer set temperature by mixing hot heat transfer medium from the upper port (2a) of the buffer memory (2) and from a cold heat transfer medium from the return line (16) to the consumer (3, 13) regulated becomes. 4. The method according to any one of claims 1 to 3, characterized in that when a consumer set temperature above a buffer storage temperature at the upper port (2a) of the buffer memory (2), the boiler (1) is turned on and over Mixing valve (4, 14) the connection to the boiler flow connection (la) is opened and the consumer 10/18 10 set temperature by mixing hot heat transfer medium from the boiler flow connection (la) and a cold heat transfer medium from the return line (16) to the consumer (3 13). 5. The method according to any one of claims 1 to 4, characterized in that a first consumer (3) and at least one further consumer (13) by a first mixing valve (4) and at least one further mixing valve (14) are supplied. 6. The method according to any one of claims 1 to 5, characterized in that the heat transfer medium by a between the mixing valve (4, 14) and the consumer (3, 13) arranged heating pump (5, 15) is conveyed. 7. The method according to any one of claims 1 to 6, characterized in that via a follower extension section (L3a) optionally heat transfer medium from the boiler flow connection (la) to the upper port (2a) of the buffer memory (2) is promoted. 8. Heating system for supplying at least one consumer (3, 13), with a boiler (1) having a boiler flow connection (la) and a boiler return port (lb), and with a buffer memory (2) having an upper terminal (2a ) and a lower connection (2b), wherein the boiler flow connection (la) of the boiler (1) is connected to a mixing valve (4, 14) which is in communication with a consumer (3, 13), characterized in that the Mixing valve (4, 14) further communicates with both the upper port (2a) of the buffer memory (2) and with a return line (16) connecting the lower port (2b) of the buffer memory (2), the boiler return port (lb) and a consumer (3, 13) interconnects. 9. Heating installation according to claim 8, characterized in that the mixing valve (4, 14) is adapted to mix a variable flow rate of the heat transfer medium from the return line (16) to a consumer (3, 13) supplied flow rate of the heat transfer medium. 11/18 11 10. Heating system according to claim 8 or 9, characterized in that the mixing valve (4, 14) is adapted to selectively interrupt the connection to the boiler flow connection (la) or the upper port (2a) of the buffer memory (2). 11. Heating installation according to one of claims 8 to 10, characterized in that a heating pump (5, 15) between the mixing valve (4, 14) and the consumer (3, 13) is arranged. 12. Heating system according to one of claims 8 to 11, characterized in that a Nachlaufverlängerungsabschnitt (L3a) between the boiler supply port (la) and the upper port (2a) of the buffer memory (2) is provided. 13. Heating system according to claim 12, characterized in that in the wake extension section (L3a), a follower pump (6) is provided. 14. Heating system according to one of claims 12 or 13, characterized in that follower extension section (L3a) represents a direct hydraulic connection between the boiler flow connection (la) and the upper port (2a) of the buffer memory (2). 15. Heating system according to one of claims 8 to 14, characterized in that a first consumer (3) with a first mixing valve (4) and at least one further consumer (13) with at least one further mixing valve (14) is connected. 16. mixing valve for a heating system according to one of claims 8 to 15, characterized in that the mixing valve (4, 14) has a consumer connection (4a, 14a), a boiler connection (4b, 14b), a buffer connection (4c, 14c) and a Return port (4d, 14d) and that the consumer port (4a, 14a) in a variable ratio to another port and to the return port (4d, 14d) is in communication, the further port optionally the boiler port (4b, 14b) or the buffer terminal (4c, 14c) is. 12/18 12 17. Mixing valve according to claim 16, characterized in that when connecting the boiler connection (4b, 14b) to the load connection (4a, 14a) the buffer connection (4c, 14c) is interrupted and that upon connection of the buffer connection with the consumer connection (4a, 14a ) of the (4c, 14c) boiler connection (4b, 14b) is interrupted. 2012 09 13 Ba / St 13/18