Variable flow control method for a return water mixed constant temperature heating system

Abstract

The application provides a variable flow control method for a return water mixing constant temperature heating system, and belongs to the technical field of heat exchangers, and comprises the following steps: monitoring the pressure and temperature of primary network water supply; monitoring the water mixing pressure in a water mixer; monitoring the pressure and temperature of secondary network water supply, i.e. user side water supply; monitoring the pressure and temperature of primary network return water; simultaneously setting standby water pumps at the secondary network water supply and the primary network return water, and setting an electric regulating valve at the primary network water supply; calculating the difference between the primary network water supply pressure and the water mixing pressure according to a derived formula; and adjusting the electric regulating valve according to the calculated pressure, so that the mixed water reaches the set user side water supply temperature. The electric regulating valve is adjusted in real time according to the derived formula, the stability of system heating is enhanced, the return water waste heat is fully utilized, heat loss is reduced, and energy saving and emission reduction are achieved.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and in particular to a variable flow control method for a mixed supply and return water constant temperature heating system. Background Technology

[0002] Energy activities such as power generation and heating are major sources of carbon emissions, so there is still much room for improvement in energy conservation in heating systems.

[0003] Heating systems can be categorized based on the connection method between the heat source and the heat user: direct-connection heating systems, indirect-connection heating systems, and mixing systems. Direct-connection heating systems require less investment and are simple to operate, but the small temperature difference between the supply and return water and the large flow rate result in significant heat loss. Indirect-connection heating systems offer advantages such as system stability, ease of hydraulic balance adjustment, and lower investment, but they require larger investment in heat exchange stations, suffer from greater heat loss, and incur higher maintenance costs.

[0004] The advantages of mixed-flow heating systems include low investment, easy hydraulic balance adjustment, simple operation, and more flexible heating. To reduce heat loss and fully utilize the system's heat capacity, this paper proposes a variable flow control method for a mixed-flow constant-temperature heating system. Summary of the Invention

[0005] The purpose of this invention is to provide a variable flow control method for heating systems that can reduce heat loss and make full use of system heat.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A variable flow control method for a mixed supply and return water constant temperature heating system, comprising:

[0008] Start the secondary network water pump ls3 or ls4;

[0009] When the flow rate equals the system flow rate Q, start water pump ls1 or ls2;

[0010] Let P2 - P1 = P3 - P1;

[0011] When T3 is less than the set temperature t, ΔP is calculated using the following formula.

[0012]

[0013] ΔP is changed by adjusting the valve;

[0014] Where P2 is the primary network water supply pressure, P1 is the mixing pressure in the mixer, P3 is the primary network return pressure, and ΔP is the difference between the primary network water supply pressure P2 and the mixing pressure P1. MAX Q is the upper limit of the system differential pressure. MAXQ is the system flow rate limit, t is the set user-side water supply temperature, T3 is the user-side water supply temperature, T1 is the primary network water supply temperature, and T2 is the primary network return water temperature.

[0015] Optionally, monitoring of the primary water supply pressure P2 and temperature T1 may also be included.

[0016] Optionally, monitoring the mixing pressure P1 in the mixer may also be included.

[0017] Optionally, monitoring of the secondary network water supply pressure P4 and temperature T3 may also be included.

[0018] Optionally, monitoring of the primary network return water pressure P3 and temperature T2 may also be included.

[0019] Optionally, it also includes installing standby water pumps at the secondary water supply point and the primary water return point, and installing an electric regulating valve at the primary water supply point.

[0020] Optionally, the regulating valve is adjusted according to the calculated pressure difference to achieve the set user-side water supply temperature after mixing.

[0021] The variable flow control method for a mixed supply and return water constant temperature heating system provided by this invention offers advantages over traditional heating systems, including lower investment, easier hydraulic balance adjustment, simpler operation, and more flexible heating. The electric regulating valve, based on a derived formula, performs real-time adjustments, enhancing the system's heating stability and fully utilizing waste heat from the return water to reduce heat loss, thus achieving energy conservation and emission reduction. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the variable flow control method for a mixed supply and return water constant temperature heating system provided in an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The purpose of this invention is to provide a variable flow control method for heating systems that can reduce heat loss and make full use of system heat.

[0025] To achieve the above objectives, the present invention provides a variable flow rate control method for a mixed supply and return water constant temperature heating system, comprising:

[0026] Start the secondary network water pump ls3 or ls4;

[0027] When the flow rate equals the system flow rate Q, start water pump ls1 or ls2;

[0028] Let P2 - P1 = P3 - P1;

[0029] When T3 is less than the set temperature t, ΔP is calculated using the following formula.

[0030]

[0031] ΔP is changed by adjusting the valve;

[0032] Where P2 is the primary network water supply pressure, P1 is the mixing pressure in the mixer, P3 is the primary network return pressure, and ΔP is the difference between the primary network water supply pressure P2 and the mixing pressure P1. MAX Q is the upper limit of the system differential pressure. MAX Q is the system flow rate limit, t is the set user-side water supply temperature, T3 is the user-side water supply temperature, T1 is the primary network water supply temperature, and T2 is the primary network return water temperature.

[0033] In one embodiment, the method further includes monitoring the primary water supply pressure P2 and temperature T1.

[0034] In one embodiment, the mixing pressure P1 in the mixer is also monitored.

[0035] In one embodiment, the method further includes monitoring the secondary water supply network, i.e., the user-side water supply pressure P4 and temperature T3.

[0036] In one embodiment, the method further includes monitoring the primary network return water pressure P3 and temperature T2.

[0037] In one embodiment, a backup water pump is installed at the secondary water supply network and the primary water return network respectively, and an electric regulating valve is installed at the primary water supply network.

[0038] In one embodiment, the regulating valve adjusts according to the calculated pressure difference to achieve the set user-side water supply temperature after mixing. The adjustment via the electric regulating valve can achieve real-time regulation, improve the stability of heating, make full use of the waste heat of the return water, reduce heat loss, and achieve energy-saving effect.

[0039] In one embodiment, ΔP can also be the difference between the primary return water pressure P3 and the mixing water pressure P1.

[0040] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0041] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A variable flow rate control method for a mixed supply and return water constant temperature heating system, characterized in that, include: Start the secondary network water pump ls3 or ls4; When the flow rate equals the system flow rate Q, start the water pump ls1 or ls2 located in the primary network return water pipeline; make P 2- P 1= P 3- P 1; when T When the temperature is less than the set temperature t, the following formula is used to calculate... , ； Change by adjusting the valve This ensures that the mixed water supply temperature reaches the set user-side water supply temperature t. in, P 2 represents the primary water supply pressure. P 1. Mixing pressure in the mixer P 3 represents the primary network return water pressure. For the primary network water supply pressure P 2 and mixing pressure P The difference of 1 This is the upper limit of the system differential pressure. This is the system's maximum traffic limit. The system flow rate is given by t, where t is the set user-side water supply temperature. For the user-side water supply temperature, For the primary water supply temperature, This refers to the return water temperature of the primary network.

2. The variable flow control method for a mixed supply and return water constant temperature heating system according to claim 1, characterized in that, Also includes: water supply pressure of the primary network P 2. Temperature T 1. Conduct monitoring.

3. The variable flow control method for a mixed supply and return water constant temperature heating system according to claim 1, characterized in that, Also includes: Mixing pressure in the mixer P 1. Conduct monitoring.

4. The variable flow control method for a mixed supply and return water constant temperature heating system according to claim 1, characterized in that, Also includes: Water supply pressure in the secondary network P 4. Temperature T 3. Conduct monitoring.

5. The variable flow control method for a mixed supply and return water constant temperature heating system according to claim 1, characterized in that, Also includes: For the primary network return water pressure P 3. Temperature T 2. Conduct monitoring.

6. The variable flow control method for a mixed supply and return water constant temperature heating system according to claim 1, characterized in that, Also includes: A backup water pump is installed at both the secondary water supply network and the primary water return network, and an electric regulating valve is installed at the primary water supply network.

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