CN118076836A - Heating system with automatic pressure difference setting - Google Patents

Heating system with automatic pressure difference setting Download PDF

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Publication number
CN118076836A
CN118076836A CN202280066687.1A CN202280066687A CN118076836A CN 118076836 A CN118076836 A CN 118076836A CN 202280066687 A CN202280066687 A CN 202280066687A CN 118076836 A CN118076836 A CN 118076836A
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CN
China
Prior art keywords
pressure difference
heating system
flow
pressure
setting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202280066687.1A
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Chinese (zh)
Inventor
博什蒂安·多伦茨
莱尔·查瓦里
内伊克·科兹耶克
博扬·莫丝兹
桑德罗·泰尔齐奇
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Danfoss AS
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Danfoss AS
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Publication of CN118076836A publication Critical patent/CN118076836A/en
Pending legal-status Critical Current

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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
    • F24D19/00—Details
    • F24D19/10—Arrangement or mounting of control or safety devices
    • F24D19/1006—Arrangement or mounting of control or safety devices for water heating systems
    • F24D19/1009—Arrangement or mounting of control or safety devices for water heating systems for central heating
    • F24D19/1015—Arrangement or mounting of control or safety devices for water heating systems for central heating using a valve or valves
    • F24D19/1036—Having differential pressure measurement facilities
    • 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
    • F24D10/00—District heating systems
    • F24D10/003—Domestic delivery stations having a heat exchanger
    • 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
    • F24D19/00—Details
    • F24D19/10—Arrangement or mounting of control or safety devices
    • F24D19/1006—Arrangement or mounting of control or safety devices for water heating systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H15/00—Control of fluid heaters
    • F24H15/20—Control of fluid heaters characterised by control inputs
    • F24H15/242—Pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H15/00—Control of fluid heaters
    • F24H15/30—Control of fluid heaters characterised by control outputs; characterised by the components to be controlled
    • F24H15/305—Control of valves
    • F24H15/31—Control of valves of valves having only one inlet port and one outlet port, e.g. flow rate regulating valves
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00—Control of flow
    • G05D7/06—Control of flow characterised by the use of electric means
    • G05D7/0617—Control of flow characterised by the use of electric means specially adapted for fluid materials
    • G05D7/0629—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
    • G05D7/0635—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means
    • 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
    • F24D2220/02—Fluid distribution means
    • F24D2220/0264—Hydraulic balancing valves
    • 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

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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)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Fluid Mechanics (AREA)
  • Steam Or Hot-Water Central Heating Systems (AREA)

Abstract

A method for balancing a heating system (1) is provided, the heating system (1) comprising a heat exchange unit (2), a pressure regulating unit (3), a main flow controller (10 a) and at least one heat consumer (4), wherein heat exchange takes place in the heat exchange unit (2) between a primary side fluid and a secondary side fluid, wherein the secondary side fluid is supplied to the at least one heat consumer (4), and wherein the pressure regulating unit (3) is arranged to control a pressure difference in a part of the heating system (1). -changing the pressure difference in a part of the heating system (1) by means of the pressure regulating unit (3) until a flow corresponding to a nominal flow is obtained in the part of the heating system (1). -selecting the pressure difference resulting in the nominal flow as the pressure difference setting of the pressure regulating unit (3).

Description

Heating system with automatic pressure difference setting
Technical Field
The present invention relates to a method of affecting the operation of a control valve by changing system parameters in a fluid flow system when the control valve is operated under conditions that would affect the overall operation of the fluid flow system. According to the invention, this is accomplished by introducing a balancing system adapted to balance the fluid flow system to an adjustable set point, wherein the balancing system comprises a set actuator capable of adjusting the set point in response to an operating value of the control valve. In a primary but non-limiting embodiment of the invention, the fluid flow system is a heating system connected to a district heating supply, wherein the fluid flow is controlled by a control valve, and wherein the balancing system is a pressure differential controller comprising a pressure differential valve actuator. The set point is related to the pressure differential.
Background
As is well known, in heating systems, such as those used for district heating, where a remotely supplied heating fluid heats domestic water and water supplied to the heating (e.g., floor heating and radiator), one of the prerequisites for good operation (e.g., no oscillations and no noise) control is to use a pressure differential controller for balancing the pressure differential across the system (e.g., heating system).
If the pressure difference is not properly selected, there is a risk of failure, such as pressure oscillations and noise in the system. The pressure difference controller is used to maintain a pressure difference in the system regardless of the pressure difference in the supply network and the consumption in the system. The pressure differential controller is also used to create a hydraulic balance in the network.
The use of pressure difference controllers in the substation and district heating network will maintain hydraulic balance in the network, ensuring a good distribution of water in the supply network, and may achieve a desired pressure level in the network, resulting in a sufficient heat supply in the network. Proper balancing ensures that the amount of circulating water in the network can be limited, thereby providing reduced costs for water circulation. Because of the balance of the network, the pressure drop across, for example, a substation or a control valve is always a designed pressure drop and no extra energy is required for the pressure pump.
Most problems occur when the control valve is almost closed, leaving only a small through-flow, at which time control becomes difficult and may cause oscillations.
Disclosure of Invention
It is an object of embodiments of the present invention to provide a method for balancing a heating system such that oscillations in the heating system are eliminated or significantly reduced.
The present invention provides a method for balancing a heating system comprising a heat exchange unit, a pressure regulating unit, a main flow controller and at least one heat consumer, wherein heat exchange takes place in the heat exchange unit between a primary side fluid and a secondary side fluid, wherein the secondary side fluid is supplied to the at least one heat consumer, and wherein the pressure regulating unit is arranged to control a pressure difference in a part of the heating system, the method comprising the steps of:
-varying the pressure difference in a part of the heating system by means of the pressure regulating unit until a flow corresponding to a nominal flow is obtained in the part of the heating system, and
-Selecting a pressure difference resulting in the nominal flow as a pressure difference setting of the pressure regulating unit.
Accordingly, the present invention provides a method for balancing a heating system. In this context, the term "heating system" should be interpreted to mean a system providing heating, for example in the form of room heating and/or domestic water heating. The heating system may be, for example, a home heating system.
In this context, the term "balancing" should be interpreted to mean controlling the pressure difference across the heating system in a suitable manner, thereby ensuring a good distribution of fluid throughout the heating system in order to ensure an energy efficient heating system.
The heating system comprises a heat exchange unit, a pressure regulating unit, a main flow controller and at least one heat consumption device. In the heat exchange unit, heat exchange takes place between a primary side fluid and a secondary side fluid, wherein the primary side of the heat exchanger may be connected to a heating installation, for example in the form of a district heating network, geothermal heating system, solar heating system, etc. At least one heat consumer is arranged at the secondary side of the heat exchanger and thereby supplies a secondary side fluid to the at least one heat consumer.
The pressure regulating unit is arranged to control a pressure difference in a part of the heating system. Accordingly, the pressure adjusting unit is used to perform balancing of the heating system. The part of the heating system in which the pressure difference is controlled by the pressure regulating unit may be, for example, a primary side supply line, a primary side return line, a secondary side supply line, or a secondary side return line.
The main flow controller is arranged to control fluid flow in the heating system, for example in the same part of the heating system as in which the pressure difference is controlled by the pressure regulating unit. The primary flow controller may be in the form of a valve, for example.
In the method according to the invention, the pressure difference is initially changed in a part of the heating system by means of the pressure regulating unit. The pressure differential is varied until a flow corresponding to the nominal flow is obtained in the portion of the heating system. In this context, the term "nominal flow" should be interpreted to mean a flow at which the heating system is operating properly in steady state. The nominal flow is sometimes referred to as the "design flow". The flow may be, for example, a flow through a primary flow controller.
Accordingly, the pressure difference adjusting unit is operated in such a manner as to change or adjust the pressure difference in a certain portion of the heating system. At the same time, the flow in that portion of the heating system is monitored and compared to the nominal flow.
When the nominal flow is reached, the pressure difference is recorded and it can be concluded that, under the prevailing operating conditions, the pressure difference will lead to the nominal flow. Therefore, the pressure difference is selected as the pressure difference setting of the pressure adjusting means. Thus, when the pressure differential accommodating unit is subsequently operated in accordance with the set point, the pressure differential accommodating unit will also operate in a manner that seeks to obtain a nominal flow in that portion of the heating system. Thereby, a proper fluid flow through the heating system is also obtained, with no or only limited oscillations in the fluid flow.
The method may further include the step of setting the flow rate in the portion of the heating system to a maximum flow rate prior to the step of varying the pressure differential.
According to this embodiment, the above-described method is performed when the fluid flow through the portion of the heating system in which the pressure difference is controlled is as high as possible. This may be achieved, for example, by fully opening one or more valves (e.g., including a primary flow controller). The pressure differential is then varied so that the flow through the portion of the heating system gradually approaches a nominal flow, which is typically lower than the maximum flow.
The step of varying the pressure differential may comprise: the pressure regulating unit is initially set at a starting set pressure difference. According to this embodiment, a starting point for the pressure difference is selected before the above-described method is started. The initial set pressure difference may be, for example, the lowest possible setting or another predefined setting. Alternatively, the initial set pressure difference may simply be the current pressure difference setting at the start of the method, or the measured pressure difference.
The step of changing the pressure difference may be performed by changing a setting of the pressure regulating unit. According to this embodiment, the pressure difference is changed by gradually or stepwise changing the setting provided to the pressure adjusting unit. When the setting of the pressure regulating unit is changed, the pressure regulating unit will then operate in such a way that it tries to reach an actual pressure difference equal to the setting. Whereby the actual pressure difference varies according to the variation of the set value. This is a simple, accurate and reliable way of varying the pressure difference.
The step of varying the pressure difference may be performed in a stepwise manner, and the method may further comprise: for each step-wise change in pressure differential, measuring the flow in the portion of the heating system after a waiting period dt has elapsed in time.
According to this embodiment, the step of changing the pressure difference is performed as follows. The pressure differential is changed step by step and then a waiting period dt is allowed to elapse to allow the system to reach an equilibrium state. When the waiting period dt has elapsed, the flow rate of the portion in which the pressure difference in the heating system has changed is measured. The measured flow rate may then be compared to a nominal flow rate to determine if the nominal flow rate has been reached. By allowing a waiting period dt to elapse before measuring the flow, it can be ensured that the measured flow actually corresponds to the set pressure difference. If the nominal flow has not been reached, the process is repeated starting with a gradual change in the pressure difference.
The waiting period dt may be a constant period. Alternatively, the waiting period dt may be dependent on the pressure difference setting. As another alternative, the wait period dt may depend on the difference between the measured flow and the nominal flow in the portion of the heating system, e.g., with a longer wait period when the difference between the measured flow and the nominal flow is large, and a decrease in wait period when the measured flow approaches the nominal flow.
The step of varying the pressure differential may comprise: the pressure difference is ramped up (ramping up) at a constant rate. According to this embodiment, the pressure difference is initially at a low level and gradually increases when the above-described method is performed. This can be done in a stepwise manner or in a continuous manner.
The step of varying the pressure differential may be performed based on whether the flow in the portion of the heating system is above or below the nominal flow. For example, if the flow rate is lower than the nominal flow rate, the flow rate should be increased by changing the pressure differential so as to cause the nominal flow rate to be reached. Therefore, in this case, the pressure difference should be changed in such a way that an increase in flow rate can be expected. Similarly, if the flow rate is higher than the nominal flow rate, the pressure differential should be changed in such a way that a decrease in flow rate can be expected.
The method may further comprise the step of transmitting, by a remote controller, a pressure difference setting signal to a setting actuator of the pressure difference adjusting unit. According to this embodiment, the pressure difference adjusting unit is controlled by a remote controller, i.e. the remote controller defines a desired pressure difference setting and transmits a setting signal indicative of the desired pressure difference to the pressure difference adjusting unit. The setting actuator of the pressure difference adjusting unit then actuates the appropriate pressure adjusting element of the pressure difference adjusting unit in accordance with the received pressure difference setting signal, i.e. in order to try to reach the desired pressure difference.
Alternatively, the pressure difference regulating unit may be controlled by means of a local or internal controller.
The step of changing the pressure difference may be performed in dependence of the current pressure difference setting. According to this embodiment, the current or present pressure difference setting specifies the way in which the pressure difference change is performed, e.g. as to whether the pressure difference should be increased or decreased, at what rate, etc.
The heating system may also include a flow measurement device. The flow measuring device may for example be used for measuring the flow in a part of the heating system in which the pressure difference is changed, in order to determine whether the nominal flow has been reached.
The invention also provides a controller suitable for executing the method. The controller may be a remote controller or it may be a local controller, such as an internal controller of the pressure difference regulating unit.
Drawings
The invention will now be described in further detail with reference to the accompanying drawings, in which:
FIG. 1 illustrates an exemplary heating system in which a method according to the present invention may be implemented;
FIG. 2 illustrates an exemplary pressure differential controller comprised of a valve coupled to a pressure responsive actuator, an adjustable biasing device, and a set actuator; and
Fig. 3 is a flowchart illustrating automatic pressure differential setting in a substation according to an embodiment of the present invention.
Detailed Description
Detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
Fig. 1 illustrates an exemplary heating system 1 that supplies heating fluid to one or more heat consumers 4. The heating fluid is supplied to the heat exchange unit 2 at the primary side through the primary side supply line 6 at a primary side supply temperature T 11 and returned through the primary side return line 7 at a primary side return temperature T 12. The heating fluid is also referred to as primary side fluid.
The primary side main lines 6,7 are connected to any type of heating installation, such as district heating networks, geothermal heating systems, solar heating systems, etc., or a combination thereof.
In the illustrated embodiment, the heat exchanger unit 2 is connected to a secondary side heating system by a secondary side supply line 8 and a secondary side return line 9. In the heat exchanger unit 2, heat is exchanged between the secondary side fluid and the primary side fluid passing through the heat exchanger unit 2. This provides a secondary fluid which is supplied to the secondary side supply line 8 at a local supply temperature T 22 and returned to the heat exchanger 2 through the secondary side return line 9 at a secondary side return temperature T 21.
The secondary side heating system includes one or more heat consumers 4, such as radiators, floor heating systems, water hoses, etc., and any required flow controllers 10, such as valves and/or thermostats (thermostat).
The heating system 1 further comprises a pressure regulating unit 3, which pressure regulating unit 3 is positioned at the primary side supply line 6 in the illustrated embodiment and is adapted to maintaining a substantially constant pressure in the heating system 1. This allows hydraulic balancing of the primary side fluid flow independent of pressure fluctuations. The same advantages can be obtained by alternatively positioning the pressure regulating unit 3 at the primary side return line 7.
Alternatively or additionally, the pressure regulating unit 3 may be adapted to achieve hydraulic balancing of the secondary side fluid, and thus the pressure regulating unit 3 may be positioned at the secondary side supply line 8 or the secondary side return line 9.
The controller 5 may be positioned in data exchange communication with the pressure regulating unit 3, wherein the data exchange communication may be of any type, such as wireless, wired, digital, analog, etc. The controller 5 may for example be adapted to provide a set point pressure difference signal to the pressure regulating unit 3.
The temperature sensor 11 may be positioned to measure the temperature of the fluid in the heating system 1, for example to measure the temperature of the inlet and outlet of the primary and secondary sides of the heat exchanger 2 (T 11、T12、T21、T22). A temperature sensor (not shown) may also be positioned in connection with each heat consumer 4 for measuring any or all of the inlet and outlet temperatures of the passing secondary fluid(s) and/or the ambient temperature(s). The consumer of the heat consumer(s) 4 may request a certain temperature of the space accommodating a certain heat consumer (e.g. a living room), which will be reflected in the measured ambient temperature and/or the inlet temperature and outlet temperature of the heat consumer 4. For example, it may be reflected in the difference between the inlet temperature and the outlet temperature of the heat consumer 4.
In many heating systems 1, the separation between the primary side heating system and the secondary side heating system is formed by a substation 12 comprising the heat exchange unit 2. In addition, the substation 12 may include other devices such as a temperature sensor 11, a flow controller (e.g., a valve and/or thermostat), a main flow controller 10a, a pressure regulating unit 3, and an optional controller 5. Thus, the substation 12 may be installed and connected as a link between the primary side flow systems 6,7 and the secondary side flow systems 8, 9 and as a line with the associated heat consumer 4 and other components.
In general, many devices in the heating system 1, such as the flow control devices 10, 10a (e.g. in the form of valves and/or thermostats), the pressure regulating unit 3, the heat exchange unit 2 and thus the substation 12 observe non-linear and dynamic behaviour. This affects the secondary side supply temperature T 22 of the output of the heat exchange unit 2 in a non-linear manner, for example when the secondary side flow changes. Similarly, a change in pressure on the primary side will also affect the secondary side supply temperature T 22.
The controller 5 is adapted to control and regulate the operation of the heating system 1, such as the flow, pressure and temperature of the fluid into and out of the heat exchange unit 2. The controller 5 may comprise a processor and operate as, for example, a PI or PID controller, which is referred to in this section as a PI or PID controller. The controller 5 may also comprise a memory storing required parameters such as data about operating points, operating data and nominal data or settings.
In this context, the operating point refers to the actual value of the heating system 1 in the steady state and the possible value of the substation 12.
The operating point of the substation 12 may be defined by several variables, such as the primary side flow rate, the secondary side flow rate, the inlet temperatures T 11 and T 21 of the heat exchange unit 2 (i.e. the temperature of the fluid supplied to the heat exchange unit 2, i.e. the primary side supply temperature T 11 and the secondary side return temperature T 21), the pressure difference over the primary flow controller 10a, etc. For the heating system 1 itself, the operating point may additionally comprise the inlet temperature and/or the outlet temperature of the heat consumer(s) 4, etc. In the present invention, a selected number of such variables may be used as data inputs.
In the present disclosure, the operation data refers to actual data measured or operated in the heating system 1 in general, or in the substation 12 more specifically. These data include measured data such as heat exchanger primary inlet temperature T 11, heat exchanger primary outlet temperature T 12, heat exchanger secondary inlet temperature T 22, heat exchanger secondary outlet temperature T 21, and corresponding primary and secondary side flows. This may include the latest data or a plurality of actually measured and known data, e.g. the latest N measured values, N being any natural number, possibly stored in the memory of the controller 5 or in the cloud.
The nominal data or settings are generally referred to as set operating data such as the primary inlet temperature T 11, the primary outlet temperature T 12, the secondary inlet temperature T 22, the secondary outlet temperature T 21, and the corresponding primary and secondary side flows of the heat exchanger 2. These are values that the controller 5 aims to obtain in the heating system 1 by controlling. Typically "nominal data" is also referred to as "design data", such as design flow and design pressure.
The nominal data or set point need not be the same as the data for the operating point because the dynamic requirements of the heating system 1 may "move" the set operation away from steady state. In this case, the controller 5 operates to keep the operating value stable and at least close to the nominal value or set point. The controller 5 is intended to maintain T 22 at a desired set point regardless of the operating point (e.g., secondary stream or primary inlet temperature T 11) changes.
The main flow controller 10a in the illustration is positioned at the primary side supply line 6, but may alternatively be positioned at the primary side return line 7, at the secondary side supply line 8, or at the secondary side return line 9, similar to the pressure regulating unit 3. The primary flow controller 10a may optionally be integrated into the pressure regulating unit 3, thereby forming a shared pressure and flow control unit. The main flow controller 10a may be connected to an actuator to adjust its valve opening (valve opening), wherein the actuator may be remotely controlled, for example by the controller 5. In the illustration of fig. 1, a main flow controller 10a in the form of a valve and a pressure regulating unit 3 are indicated as part of the substation 12.
By incorrect commissioning of the substation 12 for example, it can be observed that the primary side nominal flow (setpoint flow in the primary side lines 6, 7) has never been reached, and therefore the required energy cannot be supplied to the heat consumer 4 to sufficiently energize it, causing discomfort to the consumer. In the case of higher demand, this results in the secondary side supply temperature T 22 falling below the desired set point.
Focusing on the control of the temperature of the secondary side and assuming that the pressure of the primary side of the heat transfer unit 2 is stable, one cause of flow oscillations in the heating system 1 may be attributed to the operating point of the substation 12.
When the substation 12 is operating away from its nominal operating point (e.g., flow, temperature, etc. operating setting), such as the nonlinearity of the primary flow controller 10a in combination with the nonlinear heat exchanger unit 2, the PI controller 5 may cause an oscillating response of the primary flow controller 10 a. This in turn causes oscillations of the flow, which inherently propagate through the nonlinear heat exchanger unit 2. Oscillations caused by poor control may affect energy measurements, increase wear, etc. due to phase shifts between temperature and flow.
It is well known that in a heating system 1, one of the prerequisites for a well-functioning (e.g. oscillation-free and noise-free) control is the use of a pressure difference controller (e.g. a pressure regulating unit 3) for controlling the pressure difference across the system 1 and thus the hydraulic balance ensuring the hydraulic balance in the network (e.g. heating system 1).
Such a pressure difference controller 3 is used to maintain the pressure difference in the system irrespective of the pressure difference in the supply network and the consumption in the system.
The pressure regulating unit 3 according to the invention may comprise any type of pressure regulating valve suitable for controlling the pressure difference of the fluid as a whole or in a part of the heating system 1, and which pressure regulating valve may thus be in pressure communication with two locations of the heating system 1, the pressure difference between the two locations being the pressure difference. In the illustrated embodiment of fig. 1, these two locations are located on the inlet side and the outlet side, respectively, on the primary flow controller 10 a. Thus, the pressure regulating unit 3 is positioned to maintain a constant pressure differential over the main flow controller 10a to a given set point pressure differential that can be adjusted. One such exemplary pressure regulating valve can be found, for example, in European patent publication 3093729.
Fig. 2 illustrates an exemplary pressure differential controller or pressure differential regulating unit 3 comprising a valve 10b connected to a pressure responsive actuator 3 a. The pressure responsive actuator 3a may be formed as a diaphragm connected to a valve stem for changing the valve opening of the valve 10b. Both sides of the diaphragm are in pressure communication with two locations in the heating system 1, such as on the primary flow controller 10a illustrated in fig. 1.
The pressure setting may be changed by an adjustable biasing means 3b in the form of a spring element acting on the diaphragm. The setting actuator 3c is connected to the adjustable biasing means 3b to change the tension of the adjustable biasing means 3 b. The setting actuator 3c may include a processor and a memory, and may be in data exchange communication with an external device (e.g., the controller 5 illustrated in fig. 1). In one embodiment, the controller 5 may form part of the setting actuator 3 c.
The pressure difference regulating unit 3 is used in the substation 12 and the heating system 1 to maintain hydraulic balance to ensure good distribution of fluid to ensure energy efficiency of the heating system 1.
For example, when the main flow controller 10a is almost closed, only a small through-flow is left, at which time control becomes difficult and oscillation may be caused, thereby causing a problem.
In order to ensure an energy efficiency balance of the heating system 1, the pressure difference setting according to the invention is therefore adjusted according to the pressure difference setting algorithm on the main flow controller 10 a. In particular, since the pressure difference regulating unit 3 regulates in accordance with the pressure difference setting signal associated with the setpoint, it aims to find the setpoint pressure difference for the pressure difference regulating unit 3, so as to maintain this pressure difference independent of the static disturbance of the supply network connected by the primary side lines 6, 7.
The algorithm manipulates several components 3, 10a, e.g. sub-stations 12, to achieve a nominal flow through the main flow controller 10a. The flow may be measured in any suitable manner and by any suitable means, such as by a flow measurement device 13, such as a calorimeter or flowmeter, etc., which may be permanently connected as part of the substation 12 or heating system 1, or connected as desired. As illustrated in fig. 1, the flow measuring device 13 may be positioned on the primary side of the heat exchange unit 2, on the primary side supply line 6 or on the primary side return line 7.
The basic method includes varying 130 the pressure differential until a flow corresponding to the nominal flow is measured. The change of the pressure difference can be accomplished by changing the pressure difference setting of the pressure difference adjusting unit 3.
Fig. 3 illustrates the process, including a first step 100A of setting the primary flow controller 10A in a set position (e.g., a fully open position or another defined setting) prior to initiating a change 130 in pressure differential.
Another step 100B includes setting the pressure difference adjusting unit 3 to the initial set pressure difference. This may be the lowest possible setting, another predefined setting, or may simply be one that is present at the start of the algorithm, or even the actual pressure difference measured, if this does not correspond to a setting.
Then, a waiting period 110 may be introduced before checking 120A, 120B whether the respective main flow controller 10A and pressure difference regulating unit 3 are in the requested setting. If not, another time period 110 is waited. In one embodiment, a maximum aggregation time period or number of time periods is included. If a problem occurs in the heating system 1, the substation 12, the main flow controller 10a or the pressure difference adjusting unit 3 such that no setting is obtained, the algorithm will not continue but stop and possibly indicate an error.
For each change 130 in pressure differential, the flow is measured after a waiting period dt has elapsed in time. The waiting period dt in time may be constant, depending on the pressure difference setting, depending on the measured flow difference from the nominal flow, for example starting with a larger waiting period dt and then decreasing this waiting period as they approach each other.
In one embodiment, the change in pressure differential may ramp up at a constant rate. This may be the case if the pressure differential setting (step 100B) is set to a minimum value. If the pressure differential setting (step 100B) is set to a maximum value, an alternative may be to ramp down at a constant rate.
The change in pressure differential may be based on whether the measured flow is less than or greater than the nominal flow. For example, if the setting of the pressure difference is selected according to the setting at the start of the algorithm (step 100B), the variation may depend on the maximum of the measured flow and the nominal flow.
The step of varying the pressure difference may also be related to the difference between the measured flow rate and the nominal flow rate.
The pressure difference signal may be transmitted by a remote controller 5 in communication with the setting actuator 3 c.
When the measured flow 140 corresponds to the nominal flow, the current setting is set to the system set pressure differential and the algorithm stops 150. The heating system 1 returns to the normal operation of the heating system 1.
The new system set pressure difference may be stored in the controller 5 and/or the set actuator 3 c.
The algorithm may begin with the input of operational data 200, the operational data 200 including, for example, a current pressure differential and a current set pressure differential.
The algorithm may be processed by the controller 5 or possibly in the setting actuator 3c, each case comprising the required means, such as a processor and a memory.
Reference numerals
1-Heating system
2-Heat exchange Unit
3-Pressure regulating unit
3 A-adjustable pressure responsive actuator
3 B-Adjustable biasing means
3 C-setting actuator
4-Heat consuming device
5-Controller
6-Primary side supply line
7-Primary side return line
8-Secondary side supply line
9-Secondary side return line
10-Flow controller
10 A-Main flow controller
10 B-valve
11-Temperature sensor
12-Substation
13-Flow measuring device
100A-set the primary flow controller 10A in the fully open position prior to initiating the ramp up of the pressure differential
100B-setting the pressure regulating unit 3 to the initial set pressure differential
110-Wait for a period of time
120A-check if the primary flow controller 10A is in the requested setting
120B-check if the pressure differential accommodating unit 3 is in the requested setting
130-Change pressure differential
140-When the measured flow corresponds to the nominal flow, the current setting is set to the system pressure differential
150-Exit algorithm and return to normal operation of heating System 1
200-Running data
T 11 Primary side supply temperature
T 12 Primary side Return temperature
T 21 Secondary side Return temperature
T 22 Secondary side supply temperature

Claims (14)

1. A method for balancing a heating system (1), the heating system (1) comprising a heat exchange unit (2), a pressure regulating unit (3), a main flow controller (10 a) and at least one heat consumer (4), wherein heat exchange takes place in the heat exchange unit (2) between a primary side fluid and a secondary side fluid, wherein the secondary side fluid is supplied to the at least one heat consumer (4), and wherein the pressure regulating unit (3) is arranged to control a pressure difference in a part of the heating system (1), the method comprising the steps of:
-varying the pressure difference in a part of the heating system (1) by means of the pressure regulating unit (3) until a flow corresponding to a nominal flow is obtained in the part of the heating system (1), and
-Selecting the pressure difference resulting in the nominal flow as the pressure difference setting of the pressure regulating unit (3).
2. The method of claim 1, further comprising: a step of setting the flow rate in the portion of the heating system (1) to a maximum flow rate before the step of changing the pressure difference.
3. The method of claim 1 or 2, wherein the step of varying the pressure differential comprises: the pressure regulating unit (3) is initially set at a starting set pressure difference.
4. Method according to any of the preceding claims, wherein the step of changing the pressure difference is performed by changing a setting of the pressure regulating unit (3).
5. The method according to any of the preceding claims, wherein the step of varying the pressure difference is performed in a stepwise manner, and wherein the method further comprises: for each step-by-step change in pressure difference, measuring the flow in the portion of the heating system (1) after a waiting period dt has elapsed in time.
6. The method of claim 5, wherein the wait period dt is a constant period of time.
7. The method of claim 5, wherein the wait period dt is dependent on the pressure differential setting.
8. A method according to claim 5, wherein the waiting period dt depends on the difference between the measured flow in the part of the heating system (1) and the nominal flow.
9. The method of any one of the preceding claims, wherein the step of varying the pressure differential comprises: the pressure difference is ramped up at a constant rate.
10. A method according to any one of the preceding claims, wherein the step of varying the pressure difference is performed based on whether the flow in the portion of the heating system (1) is higher or lower than the nominal flow.
11. The method according to any of the preceding claims, further comprising the step of transmitting a pressure difference setting signal by a remote controller (5) to a setting actuator (3 c) of the pressure difference adjusting unit (3).
12. A method according to any of the preceding claims, wherein the step of varying the pressure difference is performed in dependence of a current pressure difference setting.
13. The method according to any one of the preceding claims, wherein the heating system (1) further comprises a flow measuring device (13).
14. A controller (5) adapted to perform the method according to any of the preceding claims.
CN202280066687.1A 2021-12-14 2022-11-25 Heating system with automatic pressure difference setting Pending CN118076836A (en)

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DKPA202170616 2021-12-14
DKPA202170616 2021-12-14
PCT/EP2022/083247 WO2023110361A1 (en) 2021-12-14 2022-11-25 Heating system with automatic differential pressure setting

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Publication number Priority date Publication date Assignee Title
CN102216691B (en) * 2008-07-25 2014-07-16 贝利莫控股公司 Method for the hydraulic compensation and control of a heating or cooling system and compensation and control valve therefor
DE102010022763A1 (en) * 2010-06-05 2011-12-08 Oventrop Gmbh & Co. Kg Method for automatic hydraulic balancing in fluid-carrying systems
IT1402031B1 (en) * 2010-10-14 2013-08-28 Fimcim Spa AIR-CONDITIONING SYSTEM
DK180259B1 (en) 2015-03-26 2020-09-17 Danfoss As A method of operating a valve actuator for a balancing valve

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