Method for adjusting a bypass valve of a heating circuit of an air conditioning system, air conditioning system and computer program

Abstract

A method for adjusting a bypass valve (5) between a flow (3) and a return (4) of a heating circuit (2) of an air conditioning system (1) is presented, wherein the heating circuit (2) also incorporates one or more consumers (9) and is connected to an air conditioning unit (11). The method comprises at least the following steps: a) performing a static hydraulic balancing of the heating circuit (2), b) determining a maximum pressure loss of the heating circuit (2) as a setting value for the bypass valve (5), and c) adjusting the bypass valve (5) according to the setting value determined in step b). The method enables a particularly precise calculation of a setting value for a bypass valve (5) and thus particularly energy-efficient and comfortable operation of the air conditioning system (1). A computer program and an air conditioning unit (11) are also presented.

Description

[0001] The invention relates to a method for adjusting a bypass valve of a heating circuit of an air conditioning system, an air conditioning system and a computer program.

[0002] Air conditioning systems are used to heat or cool buildings. These systems typically have one or more heating circuits to transfer heat into or out of the building's rooms. A heat transfer medium, often heating water, circulates within a heating circuit. A heating circuit can include multiple consumers, such as radiators, underfloor heating, or fan-assisted convectors. Heating appliances designed to burn fuel or heat pumps can be used as heat generators in the air conditioning system. Heat pumps can be used advantageously for both heating and cooling by reversing the refrigeration cycle.

[0003] Air conditioning systems typically include a bypass valve, also known as a relief valve, which is installed in a bypass line between the flow and return lines of a heating circuit. The bypass valve opens when a preset pressure drop is reached, thus ensuring a minimum or nominal flow rate, particularly when many or all valves of the consumers in the heating circuit are closed. The maximum pressure drop required to open the valve can be crucial for the functionality and efficiency of the air conditioning system. Such bypass valves are described, for example, in DE 40 39 644 A1, DE 10 20177 010 891 A1, and DE 10 2012 013 334 B4. Setting the pressure drop too low can result in insufficient supply to consumers in the heating circuit.An excessively high set pressure drop causes the bypass valve to open too late or not at all, thus preventing the required minimum or nominal flow rates from being maintained. A bypass valve is typically set to a theoretically calculated value or based on experience. A differential pressure valve used as a bypass valve is described as an example in EP 0 001 826 A1. Setting the differential pressure to a theoretically determined or experience-based value is very imprecise and, if it deviates from the optimal pressure for the heating circuit, can reduce the efficiency of the air conditioning system and also cause unpleasant noise in the area of ​​the consumer valves.

[0004] Based on this, the object of the invention is to propose a method for adjusting a bypass valve of a heating circuit of an air conditioning system, an air conditioning system, and a computer program that at least partially overcomes the problems of the prior art described above. In particular, it should enable the most precise possible adjustment of the bypass valve with minimal effort. Furthermore, the proposed method should not significantly complicate the configuration process of an air conditioning system.

[0005] These problems are solved by the features of the independent claims. Further advantageous embodiments of the solution proposed here are specified in the independent claims. It should be noted that the features listed in the dependent claims can be combined with one another in any technologically meaningful way and define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, which also presents further preferred embodiments of the invention.

[0006] This involves a method for adjusting a bypass valve, wherein the bypass valve is arranged between a flow and a return line of a heating circuit of an air conditioning system, and the heating circuit also includes one or more consumers and is connected to an air conditioning unit. The method comprises at least the following steps: a) Performing a static hydraulic balancing of the heating circuit, b) Determining a maximum pressure loss of the heating circuit as a setting value for the bypass valve, c) Setting the bypass valve according to the setting value determined in step b).

[0007] Steps a), b), and c) are performed at least once in the specified order during a regular procedure. This procedure is used, in particular, to determine and set a precise value for a bypass valve in a heating circuit. The procedure can be performed, especially during the installation of an air conditioning system.

[0008] The climate control system is a system for air conditioning, in particular for air conditioning at least one building. The climate control system is characterized in particular by an air conditioning unit and an associated heating circuit (supply circuit) for heat transfer, which requires hydraulic balancing for efficient operation. The heating circuit includes, in particular, a liquid medium as a heat transfer fluid, to which heat can be added and removed, or which can transport added heat. The heat transfer fluid is frequently water. The heat transfer fluid can circulate in the heating circuit, which is preferably closed, by means of a circulation pump as required. In this context, it should be noted that the term "heating circuit" does not imply a restriction to heating operation, but that a heating circuit can also be suitable for cooling operation.

[0009] In particular, the climate control system can be a heating system, typically comprising a heating circuit with a circulation pump. A heating system usually includes a heating unit containing a heat generator, such as a burner for oil, gas, or hydrogen as fuel, or a heat pump. The heat flow generated by the heat generator can be transferred to the heat transfer medium in the heating circuit and thus supplied to consumers (e.g., radiators, underfloor heating, or fan convectors) within the heating circuit. These consumers may include control valves for adjusting the flow rate and thus the heat output (or input) as needed. These control valves are often designed as thermostatic valves that automatically regulate room temperature. Electronically controlled control valves are also available; these can, for example, be integrated into a home network and enable remote transmission of control signals.Consumers typically also have a pre-setting valve, the permanent setting of which is determined as part of a static hydraulic balancing process. These pre-setting valves also allow for adjustment of the flow rate or flow resistance. Pre-setting and adjustment valves are often integrated into a single unit; for example, a common thermostatic valve typically offers a pre-setting option (as part of the static hydraulic balancing) and an adjustment valve for controlling heat transfer during the operation of the air conditioning system. In this respect, the pre-setting valve can define a range for the adjustment of the control valve.

[0010] The circulation pump in the heating circuit can be considered the most important component of the circuit, second only to the heat generator. The circulation pump generates a flow rate within the heating circuit, thereby supplying the heat provided by the heat generator to the connected consumers. For this purpose, the circulation pump can be located in the supply line between the bypass valve and the heat generator. In some heating systems, the circulation pump is integrated into the unit. The circulation pump achieves the flow rate by building up pressure (also known as the differential pressure between the pressure and suction sides of the pump). This pressure is counteracted by a pressure drop within the heating circuit. This pressure drop depends on the current degree of opening of the heating circuit, which is a measure of the number of consumers connected to the circuit in conjunction with the opening state of their control valves.The circulation pump can usually be operated in different pump operating modes and should be adapted to the individual needs of the specific heating circuit as part of the configuration of an air conditioning system.

[0011] The air conditioning system may include a bypass valve (overflow valve) located between the flow and return lines of the heating circuit, particularly within the housing of an air conditioning unit. The bypass valve is designed to open under a specific condition, which may involve a pressure differential between the flow and return lines. By adjusting the bypass valve, a maximum differential pressure can be set, at which point the bypass valve opens. This maximum differential pressure typically occurs during periods of low heat demand, when the thermostatic valves of the consumers are largely or completely closed. This ensures a minimum flow rate through the heat generator, reducing the pressure differential acting on the consumers.

[0012] As part of the planning of a climate control system, its design must ensure that it is adequately sized to supply a building with heating. This involves using data regarding the specific climatic conditions at the location and the structural characteristics of the building. During the design process, for example, the nominal output of an air conditioning unit and, for each room to be served, the size and heating output of the appliance can be determined to guarantee a reliable supply to the building by the climate control system. Based on the design of the climate control system (especially its dimensions, features, and / or operating mode), a specified heating and / or cooling output can be set or ensured under predetermined conditions.

[0013] Using a heating system as an example, the design process can determine the (maximum) output of a heat generator and size the consumers to be connected via a heating circuit to ensure a reliable heat supply under the specific climatic conditions at the location and the structural characteristics of the building to be supplied (especially its thermal insulation). Various methods are known for carrying out the design. For example, the specific wall, window, ceiling, and / or floor areas of each room to be supplied can be used to determine the specific (output) requirement and then select a specific consumer (e.g., radiator). Another (approximate) method uses (only) the floor areas of all rooms to be supplied and approximate information about the building's structural characteristics (thermal insulation, etc.).Heat losses) are taken into account to determine the demand and to dimension the climate system.

[0014] Once the design is complete, the heating system can be installed. After installation and before initial commissioning, the heating system should be configured. In particular, a static hydraulic balancing of the heating system should be carried out.

[0015] When configuring a climate control system, a multitude of parameters can be stored to configure and coordinate the heat generator, heating circuit, and climate control system. Static hydraulic balancing ensures that the heating circuit's consumers receive the required flow rates of heat transfer fluid for optimal heating of each room.

[0016] Static hydraulic balancing is usually performed manually by a qualified technician, especially in smaller air conditioning systems, such as those found in single-family homes. This involves adjusting the pre-setting valves of the consumers, possibly in different branches (zones) of the heating circuit, to achieve an optimal and consistent flow rate of the heat transfer fluid through each consumer. Newer air conditioning units or circulation pumps may feature software solutions to assist the technician in performing static hydraulic balancing. For example, a wireless connection can be established between a mobile device (such as a smartphone) and the circulation pump and / or the air conditioning unit, informing the technician when an optimal flow rate is reached while adjusting the pre-setting valves.

[0017] Static hydraulic balancing can also be performed using a pipe network calculation. The method of calculating the hydraulic balancing, and thus the necessary flow rates of the individual consumers, is fundamentally similar whether using a pipe network calculation or software-supported implementation, and includes the following points: Recording of room data of the rooms to be supplied, in particular room size and data of the installed consumer, carrying out a heating load calculation, determining the heat output of the consumers, determining a required volume flow of the heat transfer medium for each consumer, and adjusting the presetting valves of the consumers for the determined volume flow.

[0018] The invention is based on the idea of ​​calculating / determining a setting value for the bypass valve using data from the static hydraulic balancing.

[0019] As per step a), a static hydraulic balancing can be performed. The result is that the pre-setting valves of the consumers are adjusted so that each consumer receives an optimal flow rate. Alternatively, data from a pipe network calculation, i.e., a computational hydraulic balancing, can be recorded.

[0020] According to step b), the maximum pressure loss of the heating circuit can be determined as a setting for the bypass valve. The maximum pressure loss can also be understood as the required residual delivery head with the control valves of the consumers fully open. This determination can be carried out using measurement techniques.

[0021] According to one embodiment, determining the maximum pressure loss in step b) may include at least the following steps: b1) Fully opening all control valves of the consumers in the heating circuit, b2) Operating the circulation pump at rated power, b3) Measuring the maximum pressure loss.

[0022] Steps b1), b2), and b3) can be performed at least once in the specified order. Measuring the maximum pressure loss according to step b3) can be done, in particular, by the control electronics of the circulation pump, or by a process-executing control unit reading the data from the control electronics of the circulation pump. Alternatively, the maximum pressure loss can also be determined by pressure sensors installed in the heating circuit before and after the circulation pump.

[0023] According to an alternative approach, the maximum pressure loss can also be calculated as part of a pipe network analysis. However, the effort required for a pipe network analysis is high, and values ​​and parameters are determined through estimations and assumptions. In contrast, the maximum pressure loss is measured under real-world conditions when using a method with steps b1), b2), and b3), and is therefore advantageous.

[0024] As per step c), the bypass valve can now be adjusted to the setting value determined in step b). Specifically, the adjustment valve can be set to a value that is 5 percent to 15 percent higher than the maximum pressure loss determined in step b). This ensures that the circulation pump can operate at nominal power when the heating circuit is fully open (all adjustment valves of all consumers in the heating circuit are fully open). The bypass valve can be adjusted manually by a qualified technician or automatically by an actuator on the bypass valve.

[0025] The procedure, in particular the execution of steps b1), b2), and b3), can advantageously be automated or computer-assisted, for example, by a control unit of the air conditioning system. If the (adjustment) valves of the consumers cannot be opened electronically by the executing computer during step b), an instruction to open all (adjustment) valves can be issued. After all (adjustment) valves have been opened (manually), confirmation of the opening can be issued, and the procedure can be continued by the computer.

[0026] According to a further embodiment, the described method can be carried out as part of, or following, a computer-aided static hydraulic balancing. The computer can be used for automated data acquisition and automated generation of the hydraulic balancing report. Likewise, the computer can support the acquisition of measured values ​​by bringing the climate control system into a state of operation to be measured; for example, a computer can cause the circulation pump to build up a specific pressure or switch to a specific pump operating mode.

[0027] Another aspect being considered is the proposal for a climate control system. This system comprises at least one air conditioner, a heating circuit with at least one consumer, a circulation pump for circulating a heat transfer fluid within the heating circuit, and a control unit. The control unit can be electrically connected to at least the circulation pump and the air conditioner to enable the exchange of signals and / or data.

[0028] In addition, a computer program (product) is proposed, comprising commands that cause a computer to carry out a procedure presented here. When executed by a computer, the computer program can, in particular, perform all or some of the proposed procedure steps. Specifically, steps a) and b) can be performed by a computer. Adjusting the bypass valve can only be done using a computer program if the bypass valve is equipped with an actuator, thus enabling adjustment by computer control. Alternatively, the computer program can output the setting value for the bypass valve, determined in step b) or using a procedure with steps b1) to b3), to a display device, and this value is then set by a qualified technician on the bypass valve.

[0029] For this purpose, the computer program may establish a connection to a network, such as the Internet, and / or a data connection to a mobile device and / or to a (control and monitoring unit) of an air conditioning system.

[0030] The computer program can be executed, in particular, on a control unit of the climate control system. Alternatively, the computer program can also be executed on a mobile device (mobile phone), especially in conjunction with software to support the performance of hydraulic balancing.

[0031] The details, features, and advantageous configurations discussed in connection with the procedure may also occur in the climate system and computer program proposed here, and vice versa. In this respect, full reference is made to the explanations provided therein for a more detailed characterization of the features.

[0032] This document describes a method for adjusting a bypass valve in a heating circuit of an air conditioning system, an air conditioning system, and a computer program that at least partially solve the problems described with reference to the state of the art. In particular, the method, the computer program, and the air conditioning system contribute to a particularly precise adjustment of the bypass valve and can thus improve energy efficiency, operational reliability, and user comfort, especially by preventing noise pollution at particularly high differential pressures.

[0033] Furthermore, the invention can be implemented particularly easily, as no structural changes to a climate system may be necessary.

[0034] The invention and its technical context are explained in more detail below with reference to the accompanying figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the situations described in the figures and combine them with other components and findings from the present description. It should be emphasized that the figures, and especially the depicted dimensions, are only schematic. They show: Fig. 1: a sequence of a procedure proposed here, Fig. 2: a climate system proposed here, and Fig. 3: parameter profiles that can occur when carrying out a procedure proposed here.

[0035] Fig. 1 Figure 1 shows an exemplary and schematic representation of a procedure proposed here. The procedure is used to adjust a bypass valve 5 of an air conditioning system 1, particularly before initial commissioning. The sequence of steps a), b), and c), depicted in blocks 110, 120, and 130, can occur during a regular procedure.

[0036] Fig. 2Figure 1 also shows, by way of example and schematically, a proposed climate system 1, which in this example is implemented as a heating system. Climate system 1 can include an air conditioning unit 11, here implemented as a heating unit with a heat generator 10 that is operatively connected to a heat exchanger and can thus transfer heat to a heat transfer medium circulating in heating circuit 2. Heating circuit 2 has a flow 3 and a return 4. A circulation pump 14 can be provided to circulate the heat transfer medium in heating circuit 2; this pump can be arranged in the flow 3 between the heat generator 10 and a bypass valve 5. Heat transfer medium can be supplied to consumers 9 via the flow 3 of heating circuit 2 and returned to the air conditioning unit 11 via a return 4. Each consumer 9 can have an adjustment valve 6, comprising a pre-adjustment valve for setting a flow resistance as part of a static hydraulic balancing.Furthermore, the adjustment valve allows for the adjustment of the heat output and can be designed as a thermostatic valve. To enable automated static hydraulic balancing, the pre-setting valves of the adjustment valves 6 can be equipped with actuators that can be controlled, for example, via a wireless connection. The consumers 9 can be radiators, convectors, or surface heating systems such as underfloor or wall heating.

[0037] The bypass valve 5 can be arranged between the flow 3 and return 4 of the heating circuit 2. When the bypass valve 5 is open, heat transfer fluid can flow from the flow 3 into the return 4, thus ensuring the circulation of a minimum volume flow through the heat generator 10.

[0038] A control unit 8 can be configured to regulate and control the operation of the heat generator 10 or the air conditioning unit 11. For this purpose, the control unit 8 can be electrically connected to the circulation pump 7 and the heat generator 10, as well as to other devices, for example, temperature sensors in the flow 3 and return 4, or, if applicable, actuators of the control valves 6.

[0039] In block 110, a static hydraulic balancing of heating circuit 2 of the air conditioning system 1 can be carried out in step a). For this purpose, a wireless connection can be established between a mobile device (e.g., a smartphone) and the circulation pump 7 and / or the air conditioning unit 11, and a specialist can be informed when an optimal flow rate is reached during the adjustment of the presetting valves of the control valves 6.

[0040] In block 120, according to step b), the maximum pressure loss of heating circuit 2, i.e., an opening condition or setting value for the bypass valve 5, can be determined. For this purpose, all control valves 6 of heating circuit 2 can be fully opened and the circulation pump 7 operated at maximum flow rate. The maximum pressure loss of the circulation pump 7 can then be determined, in particular measured.

[0041] In block 130, the setting value determined in step b) can now be set on bypass valve 5 according to step c). This can be done manually by entering the value on an adjustment device of bypass valve 5 or, if present, by controlling an actuator of bypass valve 5. In particular, a value 5 percent to 15 percent higher than the maximum pressure loss determined in step b) can be set. Reference symbol list

[0042] 1. Air conditioning system 2. Heating circuit 3. Flow 4. Return 5. Bypass valve 6. Adjustment valve 7. Circulation pump 8. Control unit 9. Consumer 10. Heat generator / heat exchanger 11. Air conditioner

Claims

1. Method for adjusting a bypass valve (5) between a flow line (3) and a return line (4) of a heating circuit (2) of an air conditioning system (1), wherein the heating circuit (2) also incorporates one or more consumers (9) and is connected to an air conditioning unit (11), comprising at least the following steps: a) carrying out a static hydraulic balancing of the heating circuit (2), b) determining a maximum pressure loss of the heating circuit (2) as a setting value for the bypass valve (5), c) adjusting the bypass valve (5) according to the setting value determined in step b).

2. Method according to claim 1, wherein the determination of the maximum pressure loss in step b) comprises the following steps: b1) Completely opening all adjustment valves of the consumers (9) of the heating circuit (2), b2) Operating the circulation pump (14) at rated power, b3) Measuring the maximum pressure loss.

3. Method according to one of the preceding claims, wherein in step c) the bypass valve (5) is set to a value in a range of 5 percent to 15 percent greater than the maximum pressure loss determined in step b).

4. Method according to one of the preceding claims, wherein the static hydraulic balancing of the heating circuit (2) in step a) is carried out computer-aided.

5. Air conditioning system (1) comprising an air conditioning unit (11), a heating circuit (2) with at least one consumer (9) and a circulation pump (14) for circulating a heat transfer medium in the heating circuit (2) and a control and regulating unit (13) as well as means arranged to carry out a method according to claim 2.

6. Computer program comprising instructions which cause a computer to carry out steps b1) to b3) of a method according to claim 2 with an air conditioning system (1) according to claim 5.

7. Computer program according to claim 6, wherein the computer program is configured to support the implementation of step a) of a method according to claim 1.

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