AU9140301A

AU9140301A - Central heating for rooms to be heated

Info

Publication number: AU9140301A
Application number: AU91403/01A
Authority: AU
Inventors: Albert Bauer
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-11-20
Filing date: 2001-11-19
Publication date: 2002-05-23
Also published as: EP1207357A3; JP2002195581A; CA2363340A1; DE10057416A1; EP1207357A2

Description

AUSTRALIA

Patents Act 1990 Albert Bauer COMPLETE SPECIFICATION STANDARD PATENT 0* Invention Title: Central heating for rooms to be heated The following statement is a full description of this invention including the best method of performing it known to us:- CENTRAL HEATING FOR ROOMS TO BE HEATED The invention pertains to a central heating system for rooms to be heated according to the type specified in the preamble of Claim 1.

Known central heating systems generally have a heat source and a line system for transporting a thermal medium to the individual rooms. As a rule, water is used as the thermal medium.

Depending on the complexity of the heating system, the line system is composed of several subcircuits which extend, for instance, in individual floors of a multistory building. The subcircuits are supplied by vertical lines.

As a rule, a subcircuit of the line system consists of separate subcircuit supply and return lines, at least one line barrier and several heating circuits parallel to one another connected to the subcircuit supply and return lines. A heating circuit can have only one heating element or several heating elements arranged in series and connected 15 via supply and return lines to the supply and return lines of the subcircuit.

In the supply line, a line barrier is arranged at the start of each subcircuit. The line barrier ensures a uniform distribution of water in the subcircuits. It is intended thereby to minimize irregular flow through the heating circuits and thus the heating elements because of, for instance, the long distance from the vertical supply line or to S 20o frictional losses due to pipe curvatures.

The regulation or control of desired room temperature is accomplished by way of valves, specifically, temperature control valves, inserted into the heating circuits. The valve aperture and thus the volume flow of thermal medium flowing into the heating circuits or heating elements is regulated by a pressure-sensitive actuator. A spring acts in the closing direction on the actuator.

Known central heating systems have the disadvantage that the installed circuit barriers produce pressure gradients of varying magnitudes independently of the flow amount. The hysteresis of the valves increases or is displaced; in particular, the individual temperature settings of the individual rooms cannot be guaranteed.

If the central heating system is operating in the full load range, then there is a high flow velocity of the thermal medium in the line system. Associated with this high flow velocity, however, is a high pressure gradient at the circuit barriers. This has the consequence that a smaller differential pressure is present at the valves for controlling the flow of the thermal medium and thus a larger differential force consisting of differential pressure and spring force acts in the closing direction on the actuator. The S actuator is consequently pressed in the closing direction, so that the volume flow of thermal medium decreases. The premature valve closure induced thereby has the result 15 that the room temperature set/desired at the valves is not reached. In order to reach the desired room temperature nonetheless, manual readjustment at the valves is required, which is linked to increased energy consumption and increasing costs.

A similar phenomenon occurs in the partial load range of the central heating unit.

0 0. Because of the then prevailing low flow velocity of the thermal medium, only a small 0.ooo S 20 pressure gradient can be observed at the circuit barriers. This has the consequence that a higher pressure is present at the valves inserted into the heating circuits and therefore a lower differential pressure acts in the closing direction on the actuator. The actuator is thereby pressed less in the closing direction. Because of the elevated pressure, the valves close with a temporal offset, that is to say, at higher room temperatures. This is once again associated with elevated energy consumption and rising costs.

The invention is based on the problem of refining a central heating system for rooms to be heated according to the type specified in the preamble of Claim 1 such that energy savings are achieved by avoiding the aforementioned disadvantages with a simple design.

This problem is solved by the characterizing features of Claim 1 in conjunction with the features of its preamble.

The invention is based on the insight that, by setting a nearly constant pressure level in the line system of the heating system, particularly at the valves, large energy savings and a reduction of operating costs are possible.

According to the invention, therefore, each heating circuit is assigned a flow .0.0 limiter inserted in the supply or return line, independently of the number of heating S elements in the heating circuit. A constant pressure level at the valves can thereby be 15 guaranteed in a simple manner.

In order to ease the design of larger heating systems consisting of vertical lines and several subcircuits, the installation of flow limiters is now done exclusively in the supply and return lines of the heating circuits. The circuit barriers previously utilized are now unnecessary.

It is of no consequence whether a heating circuit contains only one heating element or several heating elements connected in series. The flow limiter in the heating circuit may be installed in the supply flow line, optionally upstream or downstream of a valve, as well as in the return flow line.

Depending on the embodiment of the invention, the flow limiter and the valve may be designed as an integral structural unit.

The flow limiters are designed so that an equally large pressure gradient is achieved at all flow limiters, independently of the existing pressure conditions and, in particular, independently of the size, number and construction of the heating element in a heating circuit.

The installation site of the flow limiters in the individual heating circuits may be consistent or different for all subcircuits of a heating system.

So that good maintenance of the system can be assured, the flow limiters are inserted interchangeably into the line network.

According to one embodiment of the invention, the flow limiters are laid out such that an equally large pressure gradient is achieved at all flow limiters, independently of the existing pressure conditions and, in particular, independently of the size, number and construction of the heating elements of a heating circuit. This is important when 15 heating elements of different size, which are supplied differently by differing amounts of o thermal medium per unit time, are employed. The flow limiter is thus designed in regard to its size as a function of the size of the heating element and as a function of the S pressure in the line network.

Additional characteristics and advantages may be deduced from the description below of an embodiment of the invention in conjunction with the drawing. Shown is: Figure 1, a schematic circuit diagram of a central heating system according to the invention in a building consisting of several floors.

Figure 1 schematically shows a building 2 that comprises a service room 4 in the basement for accommodating the heat source 6 and three heated stories 8a-8c, namely ground floor 8a, first upper floor 8b and second upper floor 8c. Three subcircuits 12a- 12c which are part of a central heating unit 10 according to the invention are installed in building 2. Subcircuit 12a extends in ground floor 8a, subcircuit 12b in first upper floor 8b, and subcircuit 12c in second upper floor 8c.

Subcircuits 12a-12c each have a supply flow line 18 and a return flow line which run separately. Subcircuits 12a-12c are connected to heat source 6 via vertical lines 14 and 16, each also having a supply flow and a return flow.

In each heated story 8a-8c, three heating circuits 32-36 are connected to the corresponding subcircuit 12a-12c. Every heating circuit 32-36 is connected via an inflow line 24 to outflow 18 of the associated subcircuit 12a-12c and via a return flow line 30 to S return flow 20 of the associated subcircuit 12a-2c. While the first two heating circuits 32 and 34 each have one heating element 22, two heating elements 22 are arranged in 15 series in the third illustrated heating circuit 36. The diameters of supply flow line 18 and return flow line 20 of a subcircuit 12a-12c are identical.

A thermostat valve 28 for regulating the room temperature is inserted in the supply flow line 24 of each heating circuit 32-36.

A flow limiter 26 is installed in supply flow line 24 or return flow line 30 of each 20 heating circuit 32. The installation site of flow limiter 26 in supply line 24 or return line of each heating circuit 32-36 is identical inside a given subcircuit 12a-12c, but the installation site differs for each individual one of the three subcircuits 12a-12c. In subcircuit 12a, flow limiter 26 is downstream of the thermostat valve 28 in supply line 24 of each heating circuit 32-36, and in subcircuit 12b, flow limiter 26 is upstream of thermostat valve 28 in supply line 24 of each heating circuit 32-36. In subcircuit 12c, flow limiter 26 is inserted in return line 30 of each heating circuit 32-36 and thus downstream of thermostat valve 28 and the heating element 22 or heating elements 22.

In thermostat valves 28 that are opened in the majority of cases, for instance, differently high flow velocities of the thermal medium occur in central heating system By providing flow limiters 26 in supply flow line 24 or return flow line 30 of each heating circuit 32-36, an essentially constant flow velocity in central heating system 10 results.

Because of the essentially constant flow velocities, pressure fluctuations inside the line system of central heating system 10 are avoided, in particular, in supply flow lines 24 and return flow lines 30 of each heating circuit 32, and thus at temperature control valves 28. Consequently the hysteresis of the thermostat valves 28 with respect to one another remains unchanged. This has the advantage that the room temperature is more precisely regulated and thus manual resetting of the room temperature is no longer 15 necessary; consequently energy savings are achieved..

The invention is characterized in that considerable energy can be saved by the central installation of flow limiters in supply flow line 24, optionally upstream or .oo.oi S• downstream of thermostat valve 28, or in return flow line 30 of each heating circuit 32.

°20 List of reference numerals 2 Building 4 Service area 6 Heat source 8 8a-8c Floors Central heating system 12a-12c Subcircuits 14 Vertical line supply 16 Vertical line return 18 Supply line of a subcircuit Return line of a subcircuit 22 Heating element 24 supply flow line of a heating circuit 26 Flow limiter 28 Thermostat/temperature control valve 30 Return flow line of a heating circuit S 32 First heating circuit 34 Second heating circuit :15 36 Third heating circuit ooooo* *o o*o o

Claims

1. Central heating unit for rooms to be heated of one or more buildings with a line network with outgoing and return lines, at least one flow limiter arranged in the line network, a fluid as thermal medium in the line network, several heating circuits, each connected to the line network in parallel to one another via inflow and outflow lines, each having a valve for regulation/control of room temperature and at least one heating element, characterized in that a flow limiter, which is inserted into inflow or outflow line, is associated with each heating circuit.

2. Central heating unit according to Claim 1, characterized in that the line network consists of several subcircuits, arranged, in particular, in different floors of a building, to which subcircuits heating circuits are connected in parallel to one another.

3. Central heating system according to Claim 2, characterized in that subcircuits are supplied via supply lines, such as vertical lines.

4. Central heating system according to Claim 1 or 2, characterized in that flow 1 limiters are inserted exclusively into supply flow or return flow lines of heating circuits.

Central heating system according to one of the preceding claims, characterized in that flow limiter is installed in supply flow line of a heating circuit.

6. Central heating system according to Claim 5, characterized in that flow limiter S:is upstream of valve. •20

7. Central heating system according to Claim 5, characterized in that flow limiter is downstream of valve.

8. Central heating system according to Claim 1-4, characterized in that flow limiter is installed in return flow line of a heating circuit.

9. Central heating system according to Claim 2 and, in particular, one of Claims 3-8, characterized in that the installation site of flow limiters in supply flow or return flow line of heating circuits is uniform for all heating circuits of a subcircuit.

Central heating system according to Claim 9, characterized in that the installation site of flow limiters in supply flow or returnflow line of heating circuits is different in at least two subcircuits.

11. Central heating system according to one of Claims 1-8, characterized in that the installation site of flow limiters in supply flow or return flow line of heating circuits is uniform for all heating circuits in the line system.

12. Central heating system according to one of the preceding claims, characterized in that flow limiter is interchangeably inserted into the line network.

OoO* S"13. Central heating system according to one of the preceding claims, characterized in that valve and flow limiter form a structural unit.

14. Central heating system according to one of the preceding claims, characterized in that flow limiters are designed such that an equally large pressure gradient is realized at all flow limiters, independently of the existing pressure conditions and, in particular, independently of the size, number and construction of the heating elements of a heating circuit. 20o Dated this nineteenth day of November 2001 Albert Bauer Patent Attorneys for the Applicant: FB RICE CO