Centralized cold and heat source system and hydraulic balance adjustment method for centralized cold and heat source system

Abstract

The present invention provides a centralized cold and heat source system and a method for adjusting the hydraulic balance of the centralized cold and heat source system, wherein the centralized cold and heat source system includes: a high-temperature heat system, a low-temperature cold system, a high-temperature cold system and a low-temperature heat system. The high-temperature heat system includes a high-temperature heat main circuit, a high-temperature heat primary branch circuit, a high-temperature heat secondary branch circuit and a high-temperature heat tertiary branch circuit; the low-temperature cold system includes a low-temperature cold main circuit, a low-temperature cold primary branch circuit, a low-temperature cold secondary branch circuit and a low-temperature cold tertiary branch circuit; the high-temperature cold system includes a high-temperature cold main circuit, a high-temperature cold primary branch circuit, a high-temperature cold secondary branch circuit and a high-temperature cold tertiary branch circuit; the low-temperature heat system uses the low-temperature cold system and the pipelines of the high-temperature cold system, and the low-temperature heat system includes a connecting pipe connecting the low-temperature cold main circuit and the high-temperature cold main circuit, and a valve is arranged on the connecting pipe.

Description

Technical Field

[0001] The present invention relates to the field of air conditioning systems, and in particular to a centralized cold and heat source system and a hydraulic balance adjustment method for the centralized cold and heat source system. Background Art

[0002] In recent years, under the dual carbon goals of "carbon peak and carbon neutrality", all industries and fields have actively explored various paths to energy conservation and carbon reduction. In the field of building energy consumption, air conditioning is a major energy consumer, and the energy consumption of water pumps in centralized air conditioning systems accounts for more than 30% of the system's energy consumption. Whether the water distribution of each branch of the air conditioning water system is balanced directly affects the energy consumption of water pumps and the air conditioning effect of the service area.

[0003] In the actual operation of a large number of projects, the system has long had problems with low energy efficiency and high energy consumption of water pumps. Summary of the invention

[0004] The main purpose of the present invention is to provide a centralized cold and heat source system and a centralized cold and heat source system hydraulic balance adjustment method to solve the problem of high energy consumption of the centralized cold and heat source system in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a centralized cold and heat source system is provided, including: a high-temperature heat system, including a high-temperature heat main circuit, a high-temperature heat primary branch circuit, a high-temperature heat secondary branch circuit and a high-temperature heat tertiary branch circuit, a first butterfly valve is arranged on the high-temperature heat primary branch circuit and the high-temperature heat secondary branch circuit, a first dynamic balancing electric regulating valve and a radiator are arranged on the high-temperature heat third branch circuit, and the high-temperature heat system is supplied with water through a first water pump; a low-temperature cooling system, including a low-temperature cooling main circuit, a low-temperature cooling primary branch circuit, a low-temperature cooling secondary branch circuit and a low-temperature cooling third branch circuit, a first static balancing valve is arranged on the low-temperature cooling primary branch circuit, a second butterfly valve is arranged on the low-temperature cooling secondary branch circuit, and a low-temperature cooling A second dynamic balancing electric regulating valve and a first air-conditioning device are arranged on the third-level branch, and the low-temperature cooling system is supplied with water by a second water pump; the high-temperature cooling system includes a high-temperature cooling main circuit, a high-temperature cooling first-level branch, a high-temperature cooling second-level branch and a high-temperature cooling third-level branch, a second static balancing valve is arranged on the high-temperature cooling first-level branch, a third butterfly valve is arranged on the high-temperature cooling second-level branch, a third dynamic balancing electric regulating valve and a second air-conditioning device are arranged on the high-temperature cooling third-level branch, and the high-temperature cooling system is supplied with water by a third water pump; the low-temperature heat system adopts the pipelines of the low-temperature cooling system and the high-temperature cooling system, and the low-temperature heat system includes a connecting pipe connecting the low-temperature cooling main circuit and the high-temperature cooling main circuit, and a valve is arranged on the connecting pipe.

[0006] In one embodiment, the first air conditioning device includes a fan coil unit, a fresh air unit or an air conditioning unit.

[0007] In one embodiment, the second air conditioning device includes a dry fan coil unit or a fresh air unit.

[0008] According to another aspect of the present invention, a method for hydraulic balance adjustment of a centralized cold and heat source system is provided, and the centralized cold and heat source system is adopted, and the method for hydraulic balance adjustment of the centralized cold and heat source system includes: step S10: initial adjustment of the high-temperature heat system, the low-temperature cooling system and the high-temperature cooling system of the centralized cold and heat source system; step S20: operation adjustment of the system to be operated, wherein step S20 includes: step S21: judging whether to operate the low-temperature heat system, if yes, executing step S22, if not, executing step S23; step S22: closing the third water pump, and opening the valve on the connecting pipe, operating the low-temperature heat system, and achieving system flow balance by adjusting the frequency of the second water pump of the low-temperature cooling system; step S23: when the system is running to the maximum load, detecting the return water temperature of each primary branch of the system, and adjusting the valve on the primary branch with low return water temperature until the return water temperature of each primary branch is consistent; when the operating load changes, the system flow balance is achieved by adjusting the frequency of the water pump of the corresponding system.

[0009] In one embodiment, step S10 includes: step S11: adjusting all valves in the system to be adjusted to the fully open position, adjusting the number and frequency of operation of the corresponding water pumps, so that the system flow is 1.1 to 1.2 times the design flow; step S12: using a self-adjustment method to adjust the dynamic balancing electric regulating valves on all three-level branches of the system to be adjusted; step S13: using a simple method to adjust the butterfly valves on all secondary branches of the system to be adjusted; step S14: determining whether the system to be adjusted is a high-temperature thermal system, if so, executing step S15, if not, executing step S16; step S15: using a simple method to adjust the butterfly valve on the high-temperature hot primary branch of the high-temperature thermal system; step S16: using a reference flow ratio method to adjust the static balancing valve on the primary branch of the low-temperature cooling system or the high-temperature cooling system.

[0010] In one embodiment, step S10 includes: step S11: adjusting all valves in the system to be regulated to the fully open position, adjusting the number and frequency of operation of the corresponding water pumps, so that the system flow is 1.1 to 1.2 times the design flow; step S12: adopting a self-adjustment method to adjust the dynamic balancing electric regulating valves on all three-level branches of the system to be regulated; step S13: adopting a combination of a reference flow ratio method and a simple method to adjust the butterfly valves on all secondary branches of the system to be regulated; step S14: determining whether the system to be regulated is a high-temperature thermal system, if so, executing step S15, if not, executing step S16; step S15: adopting a simple method to adjust the butterfly valve on the high-temperature hot primary branch of the high-temperature thermal system; step S16: adopting a reference flow ratio method to adjust the static balancing valve on the primary branch of the low-temperature cooling system or the high-temperature cooling system.

[0011] In one embodiment, step S12 includes: setting initial flow values ​​for all electric balancing control valves on the three-level branches of the system to be regulated according to the designed flow, and setting the order from far to near on the same branch.

[0012] In one embodiment, step S13 includes: step S131: determine the initial flow of each secondary branch of the system to be adjusted, and determine whether the deviation between the initial flow and the design flow is within 15%. If the deviation is within 15%, no adjustment is made; if not, step S132 is executed; step S132: calculate the deviation between the initial flow and the design flow of each secondary branch, sort them according to the size of the deviation value, and adjust the butterfly valve in order from large to small. The flow of the butterfly valve of each secondary branch needs to be adjusted to n% of the design flow. The larger the deviation value, the smaller the n value corresponding to the butterfly valve.

[0013] In one embodiment, step S16 includes: step S161: determine the initial flow of each primary branch of the system to be adjusted, calculate the ratio λ of the initial flow value to the design flow value, take the minimum value λmin as the reference value, and adjust the other branches in order from large to small until the λ value is equal to λmin; step S162: measure the initial flow of each primary branch of the system to be adjusted again, and determine whether the initial flow values ​​are equal. If they are equal, end the adjustment; if they are not equal, execute step S161.

[0014] By applying the technical solution of the present invention, the centralized cold and heat source systems in winter and summer both include two systems. The high-temperature heat system in winter mainly meets the heating demand of the radiator in the room, and the low-temperature hot water system mainly meets the heating demand of the first air-conditioning device and the second air-conditioning device (air-conditioning unit, fresh air unit and fan coil). The combination of the two better meets the comfort requirements in the room; the heat sources of the two hot water systems are different, and the dual heat source system can better guarantee the heating demand. In summer, the low-temperature cold system and the high-temperature cold system meet the requirements of the temperature and humidity independent control air-conditioning system. The high-temperature cold water system mainly meets the room cooling and cooling demand, and the low-temperature cold water system meets the room dehumidification and partial cooling and cooling demand. Compared with the traditional air-conditioning system with a set of low-temperature cold water, the temperature and humidity independent air-conditioning system using the dual cold source system has high comfort and no condensation water in the room because there is no cold wind in the room, and the indoor air-conditioning quality is good; on the other hand, the cold source is independently configured according to the high and low temperature systems, the efficiency of the high-temperature cold system is greatly improved, and the system is more energy-saving.

[0015] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 A partial structural schematic diagram of a high temperature heat system according to an embodiment of a centralized cold and heat source system of the present invention is shown;

[0018] Figure 2 A partial structural schematic diagram of a low-temperature cooling system according to an embodiment of a centralized cold and heat source system of the present invention is shown;

[0019] Figure 3 A partial structural schematic diagram showing a high temperature cooling system according to an embodiment of a centralized cooling and heating source system of the present invention; and

[0020] Figure 4 A flow chart of a centralized cold and heat source system hydraulic balance adjustment method according to the present invention is shown.

[0021] The above drawings include the following reference numerals:

[0022] 10. High-temperature heat system; 11. High-temperature heat primary branch; 12. High-temperature heat secondary branch; 13. High-temperature heat tertiary branch; 14. First butterfly valve; 15. First dynamic balancing electric regulating valve; 16. Radiator; 17. High-temperature heat main circuit; 20. Low-temperature cooling system; 21. Low-temperature cooling primary branch; 22. Low-temperature cooling secondary branch; 23. Low-temperature cooling tertiary branch; 24. First static balancing valve; 25. Second butterfly valve; 26. Second dynamic balancing electric regulating valve; 27. First air-conditioning device; 28. Low-temperature cooling main circuit; 30. High-temperature cooling system; 31. High-temperature cooling primary branch; 32. High-temperature cooling secondary branch; 33. High-temperature cooling tertiary branch; 34. Second static balancing valve; 35. Third butterfly valve; 36. Third dynamic balancing electric regulating valve; 37. Second air-conditioning device; 38. High-temperature cooling main circuit. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] like Figures 1 to 3 As shown, the centralized cold and heat source system of this embodiment includes: a high temperature heat system 10, a low temperature cold system 20, a high temperature cold system 30 and a low temperature heat system. Among them, the high temperature heat system 10 includes a high temperature heat main circuit 17, a high temperature heat primary branch 11, a high temperature heat secondary branch 12 and a high temperature heat tertiary branch 13, the high temperature heat primary branch 11 and the high temperature heat secondary branch 12 are provided with a first butterfly valve 14, the high temperature heat tertiary branch 13 is provided with a first dynamic balance electric regulating valve 15 and a radiator 16, and the high temperature heat system 10 is supplied with water through a first water pump. The low temperature cold system 20 includes a low temperature cold main circuit 28, a low temperature cold primary branch 21, a low temperature cold secondary branch 22 and a low temperature cold tertiary branch 23, the low temperature cold primary branch 21 is provided with a first static balance valve 24, the low temperature cold secondary branch 22 is provided with a second butterfly valve 25, the low temperature cold tertiary branch 23 is provided with a second dynamic balance electric regulating valve 26 and a first air conditioning device 27, and the low temperature cold system 20 is supplied with water through a second water pump. The high temperature cooling system 30 includes a high temperature cooling main circuit 38, a high temperature cooling primary branch circuit 31, a high temperature cooling secondary branch circuit 32 and a high temperature cooling tertiary branch circuit 33. A second static balancing valve 34 is provided on the high temperature cooling primary branch circuit 31, a third butterfly valve 35 is provided on the high temperature cooling secondary branch circuit 32, a third dynamic balancing electric regulating valve 36 and a second air conditioning device 37 are provided on the high temperature cooling tertiary branch circuit 33, and water is supplied to the high temperature cooling system 30 through a third water pump. The low temperature heat system uses the pipelines of the low temperature cooling system 20 and the high temperature cooling system 30. The low temperature heat system includes a connecting pipe connecting the low temperature cooling main circuit 28 and the high temperature cooling main circuit 38, and a valve is provided on the connecting pipe.

[0028] Applying the technical solution of this embodiment, the centralized cold and heat source systems in winter and summer both include two systems. The high-temperature heat system 10 in winter mainly meets the heating demand of the radiator 16 in the room, and the low-temperature hot water system mainly meets the heating demand of the first air-conditioning device 27 and the second air-conditioning device 37 (air-conditioning unit, fresh air unit and fan coil). The combination of the two better meets the comfort requirements in the room; the heat sources of the two hot water systems are different, and the dual heat source system can better guarantee the heating demand. In summer, the low-temperature cold system 20 and the high-temperature cold system 30 meet the requirements of the temperature and humidity independent control air-conditioning system, the high-temperature cold water system mainly meets the room cooling and cooling requirements, and the low-temperature cold water system meets the room dehumidification and partial cooling and cooling requirements. Compared with the traditional air-conditioning system with a set of low-temperature cold water, the temperature and humidity independent air-conditioning system using the dual cold source system has high comfort and no condensation water in the room, and the indoor air-conditioning quality is good because there is no cold wind in the room of the former air-conditioning system; on the other hand, the cold source is independently configured according to the high and low temperature systems, the efficiency of the high-temperature cold system is greatly improved, and the system is more energy-saving.

[0029] More importantly, in the actual operation of a large number of projects, due to the hydraulic imbalance of the pipeline system, in order to meet the most unfavorable pipeline flow demand, the water pump flow is in an overflow state, which eventually leads to the long-term existence of large flow and small temperature difference in the system, low system energy efficiency, and high water pump energy consumption. Applying the technical solution of this embodiment, each branch of each system is provided with a specific valve, and each valve is adjusted by a corresponding adjustment method before and during the operation of the system, so that the system flow is balanced, and finally the purpose of improving the system energy efficiency and reducing the energy consumption of the water pump is achieved.

[0030] It should be noted that, in this embodiment, the low-temperature heat system uses the pipelines of the low-temperature cooling system 20 and the high-temperature cooling system 30, and the low-temperature heat system includes a connecting pipe connecting the low-temperature cooling main circuit 28 and the high-temperature cooling main circuit 38, and a valve is provided on the connecting pipe. When the low-temperature heat system needs to be operated, the third water pump of the high-temperature cooling system 30 is turned off, and the valve on the connecting pipe is opened at the same time. The low-temperature heat system uses the second water pump to supply water. The above structure enables the low-temperature heat system of the centralized cold and heat source system to use the existing system pipelines, thereby greatly reducing the cost.

[0031] It should also be noted that each level of branch and main line includes a water supply pipeline and a return pipeline.

[0032] In this embodiment, the first air conditioning device 27 includes a fan coil unit, a fresh air unit or an air conditioning unit. The second air conditioning device 37 includes a dry fan coil unit or a fresh air unit.

[0033] According to the different requirements of the terminal equipment for hot and cold water temperatures, the centralized cold and heat source system is divided into two sets of heating and cooling systems in winter and summer. The division of each system, the corresponding cold and heat source form, the terminal air conditioning form and the design temperature of supply and return water are shown in Table 1.

[0034] Table 1 Basic information of centralized cooling and heating source system

[0035]

[0036] The details of the hierarchical branches and valve settings of each system are shown in Table 2.

[0037] Table 2 Pipeline classification of each system

[0038]

[0039] Continued from the table

[0040]

[0041] like Figure 4 As shown, the present application also provides a method for adjusting the hydraulic balance of a centralized cold and heat source system. The embodiment of the method for adjusting the hydraulic balance of a centralized cold and heat source system of the present application adopts the above-mentioned centralized cold and heat source system. The method for adjusting the hydraulic balance of a centralized cold and heat source system includes: step S10: initially adjusting the high-temperature heat system 10, the low-temperature cooling system 20 and the high-temperature cooling system 30 of the centralized cold and heat source system; step S20: adjusting the operation of the system to be operated, wherein step S20 includes: step S21: judging whether to operate the low-temperature heat system, if yes, executing step S22, if not, executing step S23; step S22: closing the third water pump, and opening the valve on the connecting pipe, operating the low-temperature heat system, and adjusting the frequency of the second water pump of the low-temperature cooling system 20 to achieve system flow balancing; step S23: when the system is running to the maximum load, detecting the return water temperature of each primary branch of the system, and adjusting the valve on the primary branch with low return water temperature until the return water temperature of each primary branch is consistent; when the operating load changes, adjusting the frequency of the water pump of the corresponding system to achieve system flow balancing.

[0042] By applying the technical solution of this embodiment, before the centralized cold and heat source system is operated, the high-temperature heat system 10, the low-temperature cooling system 20 and the high-temperature cooling system 30 are initially adjusted so that each branch of the system reaches the designed flow, and then fine adjustments are made when each system is in operation. The above method can achieve the purpose of balancing the system flow. In addition, by applying the technical solution of this embodiment, since the low-temperature heat system adopts the pipelines of the low-temperature cooling system 20 and the high-temperature cooling system 30, when the low-temperature heat system is operated, the water volume of the low-temperature cooling and high-temperature cooling pipeline systems is small, and the system flow can be balanced by changing the frequency of the water pump. For other systems, during operation, it is necessary to adjust the valves on the primary branches by the reference flow ratio method until the return water temperature of each primary branch is consistent to ensure the balance of the system flow. The above method reduces the adjustment steps while ensuring a good system flow regulation effect, thereby improving the regulation efficiency.

[0043] It should be noted that the above return water temperature "consistent" includes absolute consistency and also includes the return water temperature difference being within a preset range (such as 1°C, 2°C, 3°C, etc.).

[0044] Step S10 includes: Step S11: adjusting all valves in the system to be adjusted to the fully open position, adjusting the number and frequency of operation of the corresponding water pumps, so that the system flow is 1.1 to 1.2 times the design flow; Step S12: using the self-adjustment method to adjust the dynamic balance electric regulating valves on all the three-level branches of the system to be adjusted; Step S13: using the reference flow ratio method and the simple method to adjust the butterfly valves on all the secondary branches of the system to be adjusted; Step S14: judging whether the system to be adjusted is a high-temperature heat system 10, if so, executing step S15, if not, executing step S16; Step S15: using the simple method to adjust the butterfly valve on the high-temperature heat primary branch 11 of the high-temperature heat system 10; Step S16: using the reference flow ratio method to adjust the static balance valve on the primary branch of the low-temperature cooling system 20 or the high-temperature cooling system 30. The above-mentioned adjustment method enables each branch of the system to quickly and accurately reach the design flow. It should be noted that it is also possible to first determine what system is to be adjusted, and then adjust the valves on the tertiary branch, the secondary branch, and the primary branch accordingly. Of course, in other embodiments, the simple method can also be used to adjust the butterfly valves on all the secondary branches of the system to be adjusted. In this embodiment, the combination of the reference flow ratio method and the simple method can be used to adjust the butterfly valves on all the secondary branches of the system to be adjusted, which can achieve the adjustment effect more accurately and quickly.

[0045] In this embodiment, step S12 includes: setting the initial flow value of all the electric balancing regulating valves on the three-level branch of the system to be adjusted according to the design flow, and the setting order is from far to near on the same branch. It should be noted that the above-mentioned "far" and "near" are relative to the previous branch, that is, the valve of the three-level branch close to the secondary branch is the closer valve, and the valve of the three-level branch far from the secondary branch is the farther valve. The above-mentioned adjustment method is simple, effective and efficient.

[0046] In this embodiment, step S13 includes: step S131: determine the initial flow of each secondary branch of the system to be adjusted, and determine whether the deviation between the initial flow and the design flow is within 15%. If the deviation is within 15%, no adjustment is made. If not, step S132 is executed; step S132: calculate the deviation between the initial flow and the design flow of each secondary branch, sort them according to the size of the deviation value, and adjust the butterfly valve in the order of the deviation value from large to small. The flow of the butterfly valve of each secondary branch needs to be adjusted to n% of the design flow. The larger the deviation value, the smaller the n value corresponding to the butterfly valve. The above adjustment method is simple, effective and efficient.

[0047] In this embodiment, step S16 includes: step S161: determine the initial flow of each primary branch of the system to be adjusted, calculate the ratio λ of the initial flow value to the design flow value, take the minimum value λmin as the reference value, and adjust the other branches in order from large to small until the λ value is equal to λmin; step S162: measure the initial flow of each primary branch of the system to be adjusted again, and determine whether the initial flow values ​​are equal. If they are equal, end the adjustment; if they are not equal, execute step S161.

[0048] The proposed adjustment methods for initial adjustment of each system and each branch are shown in Table 3

[0049] Table 3 The proposed adjustment methods for initial adjustment of each system and each branch

[0050]

[0051] The following describes the specific debugging steps using the low temperature cooling system as an example.

[0052] The first stage, initial adjustment:

[0053] (1) Open all valves in the system and adjust the balancing valve and electric regulating valve to the fully open position. Adjust the number and frequency of water pump operation to make the system flow rate 1.1 to 1.2 times the design flow rate.

[0054] (2) Set the initial flow values ​​of all electric balancing control valves on the 3-level branches according to the designed flow. Since the electric balancing valves will maintain the flow balance through self-adjustment in the later stage, the setting order can be from far to near on the same branch or according to the convenient route in the building.

[0055] (3) After setting the electric balancing control valves on all three-level branches, measure the initial flow of each secondary branch, such as Figure 2 The initial flow rates of the secondary branches 1-1, 1-2, 1-3, and 1-4 under branch 1 are measured respectively. Since the secondary branch valves are ordinary butterfly valves with poor regulation capability, no adjustment is required if the initial flow rate and the design flow rate deviation are within 15%. If the deviation is more than 15%, sort by deviation and adjust in descending order, such as Figure 2 Assuming that the deviation order of the secondary branches on branch 1 is 1-4, 1-3, 1-2, and 1-1, the flow on branch 1-4 will be adjusted to 80-85% of the design flow, branch 1-3 will be adjusted to 85-90% of the design flow, branch 1-2 will be adjusted to 90-95% of the design flow, and branch 1-1 will not be adjusted.

[0056] According to this method, all secondary branches under other primary roads are adjusted in sequence. From the above adjustment process, it can be seen that the adjustment of secondary branches actually adopts a combination of the reference flow ratio method and the simple adjustment method.

[0057] (4) After all secondary branches are regulated, the initial flow of all primary branches is measured, and the ratio λ of the initial flow value to the design flow value is calculated. Figure 2 The three primary branches in the 1 , 2 , 3 , take the branch with the smallest λ value as the reference branch, and the minimum value λmin as the reference value. Adjust the other branches in the order of λ value from large to small until the λ value is equal to λmin. When adjusting other branches, the reference value λmin changes. Therefore, it is necessary to adjust repeatedly 2 to 3 times until the λ values ​​of all branches are basically equal.

[0058] (5) Adjust the number and frequency of running water pumps until the total flow of the system reaches the design flow. According to the principle of proportional regulation, each branch of the system reaches the design flow, and the regulation process ends.

[0059] The second stage is operation adjustment:

[0060] After the completion of the above first stage, the initial distribution of flow is completed. The later operation needs to be adjusted in combination with the actual load conditions. The operation adjustment is relatively simple and needs to be adjusted when the load is maximum. First, the three-level branch is automatically adjusted by the electric balancing valve according to the indoor load status. The second-level branch is no longer adjusted during the operation stage. The first-level branch is adjusted according to the return water temperature of each branch, and the branch balancing valve with lower return water temperature is appropriately adjusted to the return water temperature of each branch is basically the same. When the load changes in the later stage, the system flow will be balanced by the frequency conversion of the water pump. Referring to the above steps, the low-temperature cooling system, high-temperature cooling system, and high-temperature heating system are adjusted separately. The specific debugging methods for each system are slightly different, so they will not be repeated one by one.

[0061] Regarding the regulation of the high-temperature thermal system, due to the vertical imbalance in the current heating, it is planned to complete the initial adjustment of the system before the heating season or at the beginning of the heating period. During the heating operation, each floor of each building and the problem rooms will be tested one by one, and the operation will be adjusted through measures such as setting the temperature control valve in the room and adjusting the balancing valve on the branch lines on each floor, so as to achieve basically consistent temperatures in each room on each floor.

[0062] In addition, the following preparations need to be made before initial commissioning:

[0063] (1) Collect and familiarize yourself with the drawings and materials, and conduct on-site inspections to determine whether the valve configurations of each branch of the system are consistent with the design drawings. Collect technical information from various balancing valve manufacturers, and establish contact with valve suppliers and installation units.

[0064] (2) Draw a detailed hydraulic distribution system diagram for each system based on the design drawings provided and the actual situation on site. Adjust the series and parallel relationship between valves as needed and number the valves that need to be adjusted. A table is required when making adjustments.

[0065] (3) Calculate the ideal flow rate (design flow rate) of each branch that needs to be adjusted. The ideal flow rate of each branch is determined as follows: if the design flow rate is calibrated on the drawing, it shall be determined according to the design flow rate calibrated on the drawing (the low-temperature cooling system and the high-temperature cooling system, the water distributor and each branch have calibrated the first-level branch design flow rate); if the design flow rate is not calibrated on the drawing, it shall be determined by multiplying the sum of the design flow rates of all equipment on the branch by the simultaneous use coefficient. The simultaneous use coefficient is determined by dividing the sum of the equipment design flow rates by the total design flow rate. If the first-level branch flow rate is known, the simultaneous use coefficient shall be calculated for each branch separately. If the first-level branch flow rate is unknown, the same use coefficient shall be determined according to the total design flow rate.

[0066] (4) Prepare the tables required for balancing and the equipment, tools and materials used for debugging.

[0067] (5) Check whether all shut-off valves, balancing valves and other valves are in normal positions and whether the switches are flexible; check whether the filter screen of the dust collector and the filter screen are clean; and whether the system has air collection. It is particularly important to ensure that the dust collector can work normally without dirt blockage before debugging, otherwise all subsequent work will become invalid. Therefore, if the dust collector and the filter screen are found to be dirty and blocked through inspection, the filters with problems need to be cleaned one by one before the next debugging work can be carried out.

[0068] (6) Start the circulation pump and check whether all water pumps are operating normally, whether the system pressure and temperature are normal, and whether the system constant pressure is normal.

[0069] The following is an introduction to the commonly used balancing valves

[0070] (1) Static balancing valve

[0071] The static balancing valve is a regulating valve with a special digital locking function. It adopts a DC valve body structure and has better equal percentage flow characteristics. It can reasonably distribute the flow and effectively solve the problem of uneven room temperature in the heating (air conditioning) system. At the same time, it can accurately adjust the pressure drop and flow to improve the liquid flow state in the pipe network system, so as to achieve the purpose of pipe network liquid balance and resource saving. The valve is equipped with an opening degree indicator, an opening degree locking device and a small pressure measuring valve for flow measurement. As long as the balancing valve of appropriate specifications is installed on each branch and user entrance, and locked after one-time debugging with a special intelligent instrument, the total water volume of the system can be controlled within a reasonable range, thus overcoming the unreasonable phenomenon of "large flow, small temperature difference". It can be installed on the water supply pipe or the return pipe. It is generally installed on the return pipe, especially for high-temperature loops. In order to facilitate debugging, it should be installed on the return pipe. Static balancing valves are generally suitable for constant-flow air conditioning and heating systems, especially in some different-flow constant-flow air conditioning and heating systems. When the resistance loss between the farthest loop and the nearest loop cannot be balanced by adjusting the pipe diameter, setting a static balancing valve can make it easier to achieve hydraulic balance between the loops.

[0072] (2) Dynamic balancing valve

[0073] Dynamic balancing valves are divided into two types: flow control (dynamic flow control valve) and pressure difference control, which are selected according to actual needs. Dynamic balancing valves are used to solve the branch pressure difference balance problem caused by the frequent operation of temperature control valves in each terminal device. Therefore, dynamic balancing valves are suitable for variable flow systems. The difference between them and static balancing valves is that static balancing valves need to be locked after one-time debugging through a dedicated intelligent instrument to control the total water volume of the system within a reasonable range, but each change requires the valve to be re-locked through the instrument. The dynamic one is self-powered, relying on the pressure change of the medium itself in the pipe network to automatically maintain a constant flow.

[0074] (3) Integrated dynamic balancing electric control valve

[0075] The integrated dynamic balancing electric control valve is a product that integrates dynamic balancing and electric regulation. It adopts a new design concept, which enables the control valve to dynamically balance the pressure changes of the system when the pressure fluctuates during the actual operation of the system. Therefore, the flow characteristic curve of this dynamic balancing electric valve is consistent with the ideal flow characteristic curve when it is working, without deviation. The special design ensures that the adjustment of the electric valve is only affected by the standard control signal, and is not affected by the pressure fluctuation of the system. Moreover, the flow rate corresponding to any opening position of the electric valve is unique and constant. For the HVAC system, this means that the heat (cold) delivered by the electric valve at any adjustment position is stable. Therefore, this electric valve is particularly suitable for variable flow systems with large system load changes. It has the characteristics of strong anti-interference ability, stable working state and high regulation accuracy. It avoids the disadvantage of traditional electric valves that their flow changes with system pressure fluctuations even at the same opening position. The dynamic balancing electric control valve keeps this flow unchanged. When the instruction changes, the opening of the electric valve changes, and a new flow value is designed. The balancing valve keeps the new flow unchanged. In this way, it can be unaffected by the outside world, while keeping the flow of the equipment unchanged, making the system regulation more stable. In recent years, air conditioning equipment (air conditioning units) in variable flow air conditioning systems usually use this type of valve to control the temperature of the target area through flow, dynamically balance the pressure changes of the system, and prevent the flow regulation between two or more terminal devices from interfering with each other, greatly shortening the system debugging time. Therefore, this system is highly efficient and energy-saving.

[0076] The following are some detailed adjustment methods.

[0077] (1) Proportional method (benchmark flow ratio method)

[0078] The proportional method is the reference flow ratio method. Its basic principle is that when the resistance coefficient of each heat user is constant, the adjustment of the upstream end of the system will cause the flow of each heat user to change proportionally. That is, when the valves of each heat user are not adjusted, the adjustment of the upstream end of the system will make the change of the flow of each heat user follow the law of consistent proportional imbalance. When the total flow in the thermal system fluctuates within a certain range, the water flow ratio of the parallel pipelines in the system remains unchanged. Generally speaking, when the total flow changes within the range of +30%, the flow ratio between the parallel pipelines remains unchanged. Adjust all valves (stop valves, regulating valves) in the system to the fully open position, and the temperature control valve is opened to the maximum. Measure the actual flow at each balancing valve according to the number of the balancing valve, and calculate the ratio of the actual flow to the design flow between the balancing valves in each parallel balancing valve group. Analyze the balancing valves in the parallel valve group through the flow ratio, take the balancing valve with the least flow ratio as the reference valve, and take the flow ratio of this valve as the reference flow ratio. Keep the reference valve unchanged, and adjust the flow of other balancing valves to the reference flow ratio in turn. Repeat the adjustment two or three times. Start adjusting from the last level of parallel valve group and gradually adjust to the first level. Adjust the flow at the first level balancing valve to the required theoretical flow. Due to the differences in the pipeline flow and valve elbows and other accessories of each branch of the parallel system, the pressure difference at both ends of the parallel balancing valve is not equal. Therefore, when adjusting the latter balancing valve, it will affect the previous balancing valve that has been adjusted, resulting in errors. Therefore, it is necessary to adjust repeatedly several times to control the error within 5%. The proportional method is simple in principle and has a good effect, but the balancing valve is measured too many times, the on-site adjustment is cumbersome, and the workload is large. It is not suitable for projects with many branches, complex pipelines, and large scale.

[0079] (2) Compensation method

[0080] The basis of the compensation method is the proportional method. This method relies on the adjustment of the balancing valve at the upstream end of the heating system to compensate for the change in system resistance caused by the adjustment at the downstream end, so it is called the compensation method. Specifically, in order to ensure that the flow at the balanced balancing valve in the system is not affected by other balancing adjustments, its pressure drop must be kept unchanged. The method is to change the opening of the balancing valve at the upper level to keep the pressure drop of the debugged valve unchanged when debugging other balancing valves, but never change the opening of the debugged valve. The advantage of this method is that the balancing valve of each heat user is measured only once, which relatively reduces manpower, but this method requires that all levels of branches are equipped with perfect balancing valves, otherwise it is impossible to keep the pressure drop of the debugged valve unchanged through the opening of the upper level balancing valve. In addition, this method requires three groups of personnel at the same time (the end reference user, the user to be adjusted, and the upper level branch total balancing valve). In view of the fact that the valve setting on the branch of this project is not suitable for this method, this method is not used in the following plan.

[0081] (3) Simple and fast method

[0082] The simple and quick method is a simple, easy and practical method proposed based on the long-term practice of other adjustment methods. 2 For building heating systems, the transition flow rate during the regulation process generally varies within the range of ±20% of the ideal flow rate. When a user opens a certain user's regulating valve, the flow rate of other users decreases; when a certain user's regulating valve is closed, the flow rate of other users tends to increase. Under normal circumstances, the users of a system that has not been initially regulated are all in the fully open position, so the regulation here should be carried out during the process of closing the valve. The basic steps of regulation are as follows: fully open all valves in the system, adjust the number of water pumps or the frequency converter to make the total circulation flow rate 1.1 to 1.2 times the design flow rate. Taking the heat exchange station as the benchmark, from near to far, the nearest branch line and user, adjust its transition flow rate to 80-85% of the design flow rate, the closer branch line and user, adjust the transition flow rate to 85-90% of the design flow rate, the farther branch line and user, adjust the transition flow rate to 90-95% of the design flow rate, and the farthest user flow rate to 95-100% of the design flow rate. During the adjustment process, if a branch line or a user still fails to reach the required transition flow when the regulating valve is fully opened, skip the branch line or the user and continue to adjust in the established order. After the last user is adjusted, recheck the running flow of the branch line or the user. If the deviation from the ideal flow exceeds 20%, check and eliminate the relevant faults. The simple and fast method is simple and easy to operate, with good adjustment effect, and is suitable for energy supply areas of 100,000 m 2 Cooling and heating systems on the left and right.

[0083] (4) Self-regulation method

[0084] The main feature of this method is that it relies on a self-operated regulating valve to automatically adjust and control the flow. At present, the self-operated dynamic pressure difference balancing valve and integrated electric balancing regulating valve used in variable flow systems automatically adjust the flow required by the system within a certain range through the set value, and each loop is only affected by the load changes in its own area, but not by the pressure fluctuations in the system, so it is easy to reach and maintain a balanced state. Therefore, the self-operated regulation method is based on various forms of self-operated regulating valves configured in the terminal system. The initial setting of the self-operated regulating valve is completed during the initial adjustment of the system, and the balance state is achieved and maintained through self-regulation in the later stage. The self-operated pressure difference balancing valve and the integrated electric balancing regulating valve set the pressure difference or flow of the balancing valve according to the design flow and the manufacturer's technical data.

[0085] According to the regulation method of the embodiment of the present application, the flow rate of each branch of the system is regulated, and the flow rate deviation can be controlled within 10%. In addition, after completing the hydraulic balance commissioning, combined with the adjusted state, a set of secondary station operation control strategies can be output, which is expected to reduce the energy consumption of water pump transmission and distribution by more than 10%.

[0086] It should be noted that the benchmark for a 10% drop in water pump energy consumption after hydraulic balance adjustment is the water pump energy consumption before hydraulic balance adjustment. The reason why this solution can reduce water pump energy consumption is: before the hydraulic balance adjustment, because the system was not hydraulically balanced before operation, in order to ensure the water volume at the end of the most unfavorable branch, the flow of the circulating water pump can only be increased to meet the needs of the most unfavorable end. At this time, the flow of other branches is in an overflow state. Therefore, the overall operation of the system presents a large flow and small temperature difference state. The water pump energy consumption (power consumption) is in a cubic relationship with the flow of the water pump, that is, the larger the flow of the water pump, the higher the energy consumption; after adjustment according to this solution, the hydraulic imbalance problem is solved, and the large flow and small temperature difference state is effectively alleviated. The water pump energy consumption will decrease, and it is estimated that the water pump energy consumption will decrease by more than 10%.

[0087] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0088] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0089] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for adjusting the hydraulic balance of a centralized cold and heat source system, using a cold and heat source system, comprising: A high-temperature heat system (10) comprises a high-temperature heat main circuit (17), a high-temperature heat primary branch circuit (11), a high-temperature heat secondary branch circuit (12) and a high-temperature heat tertiary branch circuit (13); the high-temperature heat primary branch circuit (11) and the high-temperature heat secondary branch circuit (12) are provided with a first butterfly valve (14); the high-temperature heat tertiary branch circuit (13) is provided with a first dynamic balance electric regulating valve (15) and a radiator (16); the high-temperature heat system (10) is supplied with water by a first water pump; A low-temperature cooling system (20) comprises a low-temperature cooling main circuit (28), a low-temperature cooling primary branch circuit (21), a low-temperature cooling secondary branch circuit (22) and a low-temperature cooling tertiary branch circuit (23); the low-temperature cooling primary branch circuit (21) is provided with a first static balancing valve (24); the low-temperature cooling secondary branch circuit (22) is provided with a second butterfly valve (25); the low-temperature cooling tertiary branch circuit (23) is provided with a second dynamic balancing electric regulating valve (26) and a first air conditioning device (27); the low-temperature cooling system (20) is supplied with water by a second water pump; and the first air conditioning device (27) comprises a fan coil unit, a fresh air unit or an air conditioning unit; A high-temperature cooling system (30) comprises a high-temperature cooling main circuit (38), a high-temperature cooling primary branch circuit (31), a high-temperature cooling secondary branch circuit (32) and a high-temperature cooling tertiary branch circuit (33); the high-temperature cooling primary branch circuit (31) is provided with a second static balancing valve (34); the high-temperature cooling secondary branch circuit (32) is provided with a third butterfly valve (35); the high-temperature cooling tertiary branch circuit (33) is provided with a third dynamic balancing electric regulating valve (36) and a second air conditioning device (37); the high-temperature cooling system (30) is supplied with water by a third water pump; and the second air conditioning device (37) comprises a dry fan coil unit or a fresh air unit; A low-temperature heat system, using the pipelines of the low-temperature cooling system (20) and the high-temperature cooling system (30), wherein the low-temperature heat system comprises a connecting pipe connecting the low-temperature cooling main circuit (28) and the high-temperature cooling main circuit (38), wherein a valve is provided on the connecting pipe, and wherein the hydraulic balance adjustment method of the centralized cold and heat source system comprises: Step S10: performing initial adjustment on the high-temperature heat system (10), the low-temperature cooling system (20) and the high-temperature cooling system (30) of the centralized cold and heat source system; Step S20: performing operation adjustment on the system to be operated, wherein the step S20 includes: Step S21: determine whether to operate the low temperature heat system, if yes, execute step S22, if no, execute step S23; Step S22: turn off the third water pump, open the valve on the connecting pipe, run the low-temperature heating system, and adjust the frequency of the second water pump of the low-temperature cooling system (20) to achieve system flow balance; Step S23: When the system is running to the maximum load, the return water temperature of each primary branch of the system is detected, and the valves on the primary branches with low return water temperatures are adjusted until the return water temperatures of each primary branch are consistent; when the operating load changes, the frequency of the water pump of the corresponding system is adjusted to achieve system flow balancing.

2. The method for adjusting the hydraulic balance of a centralized cold and heat source system according to claim 1, characterized in that: The step S10 comprises: Step S11: adjust all valves in the system to be adjusted to the fully open position, and adjust the number and frequency of operation of the corresponding water pumps to make the system flow rate 1.1 to 1.2 times the design flow rate; Step S12: using a self-adjusting method to adjust the dynamic balancing electric regulating valves on all three-level branches of the system to be adjusted; Step S13: using a simple method to adjust the butterfly valves on all secondary branches of the system to be adjusted; Step S14: determine whether the system to be adjusted is a high-temperature thermal system (10), if yes, execute step S15, if no, execute step S16; Step S15: using a simple method to adjust the butterfly valve on the high-temperature heat primary branch (11) of the high-temperature heat system (10); Step S16: using the reference flow ratio method to adjust the static balancing valve on the primary branch of the low-temperature cooling system (20) or the high-temperature cooling system (30).

3. The method for adjusting the hydraulic balance of a centralized cold and heat source system according to claim 1, characterized in that: The step S10 comprises: Step S11: adjust all valves in the system to be adjusted to the fully open position, and adjust the number and frequency of operation of the corresponding water pumps to make the system flow rate 1.1 to 1.2 times the design flow rate; Step S12: using a self-adjusting method to adjust the dynamic balancing electric regulating valves on all three-level branches of the system to be adjusted; Step S13: using a combination of the reference flow ratio method and the simplified method to adjust the butterfly valves on all secondary branches of the system to be adjusted; Step S14: determine whether the system to be adjusted is a high-temperature thermal system (10), if yes, execute step S15, if no, execute step S16; Step S15: using a simple method to adjust the butterfly valve on the high-temperature heat primary branch (11) of the high-temperature heat system (10); Step S16: using the reference flow ratio method to adjust the static balancing valve on the primary branch of the low-temperature cooling system (20) or the high-temperature cooling system (30).

4. The method for adjusting the hydraulic balance of a centralized cold and heat source system according to claim 3, characterized in that: The step S12 includes: setting the initial flow values ​​of all the electric balancing regulating valves on the three-level branches of the system to be regulated according to the designed flow, and the setting order is from far to near on the same branch.

5. The method for adjusting the hydraulic balance of a centralized cold and heat source system according to claim 3, characterized in that: The step S13 comprises: Step S131: Determine the initial flow of each secondary branch of the system to be adjusted, and determine whether the deviation between the initial flow and the design flow is within 15%. If the deviation is within 15%, no adjustment is made; if not, execute step S132; Step S132: Calculate the deviation between the initial flow and the design flow of each secondary branch, sort them according to the size of the deviation value, and adjust the butterfly valve in descending order of the deviation value. The flow of the butterfly valve of each secondary branch needs to be adjusted to n% of the design flow. The larger the deviation value, the smaller the n value corresponding to the butterfly valve.

6. The method for adjusting the hydraulic balance of a centralized cold and heat source system according to claim 3, characterized in that: The step S16 comprises: Step S161: Determine the initial flow of each primary branch of the system to be adjusted, calculate the ratio λ of the initial flow value to the design flow value, take the minimum value λmin as the reference value, and adjust the other branches in the order of λ value from large to small until the λ value is equal to λmin; Step S162: Measure the initial flow of each primary branch of the system to be adjusted again, and determine whether the initial flow values ​​are equal. If they are equal, end the adjustment; if they are not equal, execute step S161.

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