CN115076766A - Operation method for hydraulic balance of heat supply pipe network - Google Patents

Abstract

The invention relates to the technical field of heating systems, in particular to an operation method for hydraulic balance of a heating pipe network, including the establishment of a distributed heating transmission and distribution system in a primary network; a distributed transmission and distribution scheme for the entire network; The establishment of the heating transmission and distribution system includes: the determination of the zero pressure point; the analysis of the hydraulic working conditions of the heating system; the operation adjustment; the distributed transmission and distribution scheme of the whole network includes: the determination of the zero pressure point; the hydraulic working conditions of the heating system Analysis; Run Tuning. The operation method of the hydraulic balance of the heating pipe network is to set up a control platform based on data acquisition by setting up distributed circulating water pumps, wireless pressure sensors, remote transmission systems, and remote data management systems. The platform can change according to the outdoor heat load. , Automatically adjust the operating frequency of the pump, adjust the variable flow, prevent the hydraulic imbalance of the secondary network, ensure the stable and efficient operation of the distributed conveying system, and improve the heating efficiency.

Description

A kind of operation method about hydraulic balance of heating pipe network

technical field

The invention relates to the technical field of heating systems, in particular to a method for operating the hydraulic balance of a heating pipe network.

Background technique

With the continuous development of central heating and the increasing area of central heating, the main network in the old city was designed at an early age, and the rapid development of the city made the original pipe network unable to meet the operational needs. Conditions are not met. The actual operation effect is poor, and the hydraulic imbalance is serious. In order to meet the operation requirements of the most unfavorable station, the head of the main circulating water pump is increased, resulting in high operating pressure of the pipe network and waste of energy.

The advantages of using a distributed heating transmission and distribution system are: First, it can effectively improve the hydraulic working conditions of the primary network. Each heating network substation adjusts the operating parameters of the distributed water pumps according to the actual operation requirements, so as to solve the problem of large operating resistance and hydraulic pressure in the old pipe network. Second, it can effectively reduce the head of the heat source main circulating water pump, reduce the installed capacity of the water pump, and bring significant power saving effect, and at the same time can significantly reduce the overall operating pressure of the pipe network. Therefore, in recent years, the distributed heating transmission and distribution system has become an important direction for improving the efficiency of the centralized heating transmission and distribution links. At present, distributed heating and distribution systems are mostly limited to applications between heat sources, primary grids, and thermal stations. In the secondary network, heat inlet (building), and indoor heat user system, the traditional transmission method is basically maintained. In this way, the circulating water pump of the secondary network (thermal power station) is still set by the traditional design method, the heat users in the near section of the secondary network still have excessive capital head, and the hydraulic imbalance of the secondary network still exists. For this reason, the means to solve the hydraulic level of the secondary network is still to install various regulating valves and implement throttling regulation. So far, the technological advancement of the distributed transmission and distribution system has not been implemented in the secondary network and hot households. The system is fully reflected, so we propose an operation method about the hydraulic balance of the heating pipe network to solve the above-mentioned problems.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the present invention provides a method for operating the hydraulic balance of the heating pipe network, which solves the problems raised in the above-mentioned background art.

In order to achieve the above objects, the present invention is achieved through the following technical solutions: a method for operating the hydraulic balance of a heating pipe network, including the establishment of a primary network distributed heat supply and distribution system; a distributed transmission and distribution scheme for the entire network;

The establishment of the primary network distributed heat supply and distribution system includes: determination of zero pressure point; analysis of hydraulic working conditions of the heat supply system; operation adjustment;

The whole network distributed transmission and distribution scheme includes: determination of zero pressure point; analysis of hydraulic working conditions of heating system; operation adjustment; determination of distributed transmission and distribution system scheme; design principles of distributed transmission and distribution system;

The operation method about the hydraulic balance of the heating pipe network is composed of a distributed circulating water pump, a wireless pressure sensor, a remote transmission system, and a remote data management system. The remote transmission system uses the operator's 4G network, highly reliable LORA technology and Based on the fieldbus technology of in-station control, the data information of all control equipment and sensing equipment is collected by wire or wireless, and then the data is sent to the monitoring platform through GPRS, 3G, 4G, VPN or broadband, etc., and the remote data management system collects The data information of all cells in the area is analyzed, processed, stored and displayed.

The host computer system of the remote data management system adopts B/S structure or C/S structure, all data is stored in the database system, and the data display is in the form of web pages, which are visually displayed with various graphics and curves, and can be displayed on other computers without Under the condition of installing any software, log in to the system directly through the browser, and view the relevant data with the corresponding user name and password.

Preferably, the determination of the zero pressure point in the establishment of the primary network distributed heat supply and distribution system is specifically: in the water pressure diagram of the distributed heat supply and distribution system, the water supply pressure line and the return water pressure line of the main line exist. After the intersection, the water supply pressure is lower than its corresponding return water pressure.

Preferably, the analysis of the hydraulic working conditions of the heating system in the establishment of the primary network distributed heating transmission and distribution system is specifically as follows: the distributed water pump is selected according to the circulating flow and head assumed by the water pump, and the flow rate is based on the supply assumed by the water pump. The heat area and heat index are determined, and the lift is calculated from the zero pressure point, and is determined according to the circulation resistance of the main line and branch line that the pump needs to overcome.

Preferably, the operation adjustment during the establishment of the primary network distributed heat supply and distribution system is specifically: developing an advanced automatic control system based on the optimized operation of water pump variable frequency speed regulation to ensure stable and efficient operation of the distributed heat supply and distribution system.

Preferably, the determination of the zero pressure point in the whole network distributed transmission and distribution scheme is specifically: in the whole network distributed transmission and distribution system, the heat source main circulating water pump only undertakes the heat medium circulation inside the heat source, and the external circulation flow is determined by Distributed user pumps are provided, and can also be selected in the middle of the pipe network or other parts according to needs.

Preferably, the analysis of the hydraulic working conditions of the heating system in the distributed transmission and distribution scheme of the whole network is as follows: the selection of the distributed water pump needs to determine its flow and head, the flow is determined according to the user's heat index and area, and the head is zero pressure. The point is the starting point, the pressure loss and determination of the main trunk line and the branch line.

Preferably, the operation adjustment in the whole network distributed transmission and distribution scheme is specifically as follows: in the process of the primary network heating adjustment, the quality adjustment method is usually adopted according to the difference of outdoor temperature.

Preferably, the determination of the distributed transmission and distribution system scheme in the whole network distributed transmission and distribution scheme is specifically: using Geopipe hydraulic calculation software to perform pipe network modeling and simulation calculation, According to Trangen's Law:

Among them: G _i - the flow rate of each pipe section of the heating system, t/h;

ΔH _i is the pressure drop loss of each pipe section of the heating system;

η - pump efficiency;

N _{0 -} the theoretical total power of the circulating water pump calculated by Trangen's law, kW;

N The total power of the circulating water pump, Kw.

Preferably, the design principles of the distributed transmission and distribution system in the distributed transmission and distribution scheme of the whole network are as follows: the selection of the distributed water pump: the selection of the flow and the head of the distributed water pump must meet the requirements under various working conditions;

Pump outlet valve setting: In the combined operation of variable frequency and multi-pump, the working characteristic curve of the pump and the resistance curve of the pipe network also change at any time. In the actual operation process, it is necessary to grasp the change of the working point of the pump in time, and take necessary control measures; Check valve settings;

Bypass status of pipeline: When the entire pipeline is running, ensure that the bypass network of any main pipeline or branch pipeline is in a closed state.

The invention provides a method for operating the hydraulic balance of the heating pipe network, which has the following beneficial effects:

1. The operation method of the hydraulic balance of the heating pipe network is to set up a control platform based on data acquisition by setting up distributed circulating water pumps, wireless pressure sensors, remote transmission systems, and remote data management systems. When the load changes, the operating frequency of the pump is automatically adjusted, and the variable flow is adjusted to prevent the hydraulic imbalance of the secondary network, ensure the stable and efficient operation of the distributed conveying system, and improve the heating efficiency.

2. For the operation method of the hydraulic balance of the heating pipe network, the remote data management system collects the data information of all control equipment and sensing equipment by wire or wireless through the network, highly reliable LORA technology and fieldbus technology based on in-station control. , and then uniformly send the data to the monitoring platform through GPRS, 3G, 4G, VPN or broadband, etc., to ensure that the data can be quickly fed back and the timeliness of the data. In addition, the data is displayed on a web page, and users can log in to the system to view, More realistic and transparent.

Description of drawings

1 is a schematic structural diagram of a system architecture of the present invention;

Fig. 2 is the structural representation of the distributed pump design of the present invention;

Fig. 3 is the hydraulic diagram of the distributed pump design scheme of the present invention;

Figure 4 is the water pressure diagram of the traditional design scheme;

Figure 5 is the water pressure diagram before reconstruction;

Fig. 6 is the hydraulic pressure diagram after the transformation of the present invention;

FIG. 7 is a schematic structural diagram of the system flow of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

1 and 7, the present invention provides a technical solution: an operation method for hydraulic balance of a heating pipe network, including the establishment of a primary network distributed heating transmission and distribution system; a distributed transmission and distribution scheme for the entire network;

The establishment of a distributed heating transmission and distribution system in the primary network includes: the determination of the zero pressure point; the analysis of the hydraulic conditions of the heating system; the operation adjustment;

The whole network distributed transmission and distribution scheme includes: determination of zero pressure point; hydraulic condition analysis of heating system; operation adjustment; determination of distributed transmission and distribution system scheme; design principles of distributed transmission and distribution system;

The operation method of the hydraulic balance of the heating pipe network consists of distributed circulating water pumps, wireless pressure sensors, remote transmission systems, and remote data management systems. Fieldbus technology collects data information of all control equipment and sensing equipment through wired or wireless, and then sends the data to the monitoring platform through GPRS, 3G, 4G, VPN or broadband, etc., and the remote data management system collects all cells in the area. data information for analysis, processing, storage and display.

The host computer system of the remote data management system adopts B/S structure or C/S structure. All data is stored in the database system. The data display is in the form of web pages, with a variety of graphs, curves, etc. for intuitive display, and can be installed on other computers without any installation. Under the conditions of the software, log in to the system directly through the browser, and view the relevant data with the corresponding user name and password.

Please refer to Figure 1. The determination of the zero pressure point in the establishment of the primary network distributed heat supply and distribution system is as follows: In the water pressure diagram of the distributed heat supply and distribution system, the water supply pressure line and the return water pressure line of the main line exist. At the intersection point, the water supply pressure after the intersection point is lower than its corresponding return water pressure. The heat source main circulation pump only needs to overcome the hot water circulation resistance inside the heat source and the circulation resistance of the main line close to the heat source, while the circulation of the main line and branch lines far from the heat source (near the user) is required. Resistance is overcome by distributed water pumps located at substations of the heat grid.

Please refer to Figure 1. The analysis of the hydraulic conditions of the heating system in the establishment of the primary network distributed heating transmission and distribution system is as follows: the distributed water pump is selected according to the circulating flow and head it undertakes, and the flow rate is based on the heating area undertaken by the pump. The head is determined based on the zero pressure point, and is determined according to the circulation resistance of the main line and branch line that the pump needs to overcome. The selection of the pump should not only be based on the design conditions, but also comprehensively consider the typical operating conditions in actual operation. To determine, it is necessary to use powerful hydraulic simulation analysis software to model and carry out a working condition simulation calculation analysis.

Please refer to Figure 1. The operation adjustment during the establishment of the primary network distributed heat supply and distribution system is as follows: due to errors in user heat load statistics, differences between the actual operating conditions of the pipe network and theoretical operating conditions, etc., the flow rate of the distributed water pump , The lift cannot fully meet the engineering design requirements, which will still lead to the hydraulic imbalance problem of uneven flow distribution of each heating network substation in actual operation. In the early and late stages of heating, the circulation flow of the heating network is greatly reduced, and the variable frequency operation of the distributed water pump may still not meet the operating needs. The heat transmission and distribution system operates stably and efficiently. The system can automatically optimize and adjust the output power of each distributed water pump according to the heat load change of each heat network substation of the system, and adjust the variable flow to accurately meet the heating demand.

Please refer to Figure 1. The determination of the zero pressure point in the distributed transmission and distribution scheme of the whole network is as follows: in the distributed transmission and distribution system, there is a situation where the water supply pressure is lower than its corresponding return water pressure, that is, in the water pressure diagram, the supply pressure There is an intersection point between the return water pressure line. In the distributed transmission and distribution system of the whole network, the main circulation pump of the heat source is only responsible for the circulation of the heat medium inside the heat source, while the external circulation flow is provided by the distributed user pump. The middle of the net or other parts.

Please refer to Figure 1. The analysis of the hydraulic conditions of the heating system in the distributed transmission and distribution scheme of the whole network is as follows: the selection of the distributed water pump needs to determine its flow and head. The flow is determined according to the user's heat index and area, and the head is zero pressure The point is the starting point, and the pressure loss of the main line and the branch line is determined. When selecting the pump model, different operating conditions should be simulated, so advanced hydraulic calculation software should be used for calculation.

Please refer to Figure 1. The operation adjustment in the distributed transmission and distribution scheme of the whole network is as follows: during the selection of the distributed transmission and distribution system, due to the error of the user's heat load statistics, the difference between the actual operating conditions of the pipeline and the ideal operating conditions, etc. Its flow and head cannot fully meet the engineering design requirements, which will lead to unbalanced flow distribution of the system during actual operation, resulting in hydraulic imbalance. In the process of primary network heating regulation, quality and When the outdoor temperature is high at the beginning and the end of the heating period, the circulating water volume is reduced, and the power frequency operation of the pump cannot meet the operation demand.

Please refer to Figure 2-4. The determination of the distributed transmission and distribution system scheme in the whole network distributed transmission and distribution scheme is as follows: use Geopipe hydraulic calculation software to carry out pipe network modeling and simulation calculation, and determine the pump selection through multi-condition simulation analysis. Parameters, set the variable frequency water pump in the outlet pipe of the pipe network and keep the original regulating valve. When the water pump is used, the valve should be in the fully open position, and the heat source pump should be set separately. The heat source pump is integrated with the user pump. Langen's Law:

Among them: G _i - the flow rate of each pipe section of the heating system, t/h;

ΔH _i is the pressure drop loss of each pipe section of the heating system,;

η - pump efficiency;

N _{0 -} the theoretical total power of the circulating water pump calculated by Trangen's law, kW;

N The total power of the circulating water pump, Kw.

According to the calculation of the total power consumption reduction, the actual saving is the sum of the throttling ΔHi of each branch line. Compared with the traditional design scheme, the total installed power of the circulating water pump in the modified design scheme can be reduced by more than 30%.

The design principles of the distributed transmission and distribution system in the distributed transmission and distribution scheme of the whole network are as follows: the selection of distributed water pumps: the selection of the flow and head of the distributed water pump should meet the requirements of various working conditions; when the head of the power plant is fixed, Simulate the operating conditions under different flow rates, so as to select the pumps that work in the high-efficiency area according to the flow rate and the pressure head used by the user, so that the distributed pump can adapt to the working needs of various operating conditions.

Pump outlet valve setting: In the combined operation of variable frequency multi-pump, the working characteristic curve of the pump and the resistance curve of the pipe network also change at any time. In the actual operation process, it is necessary to grasp the change of the working point of the pump in time, and take necessary control measures. In operation, it is generally regulated by distributed pumps instead of valves, but in addition to the use of water pump frequency conversion regulation, such as the original electric regulating valve can be retained, so that the operation regulation under different working conditions can be adjusted with the migration of the zero pressure difference point, and the regulating valve can also be used. Adjustment, under normal conditions, the valve is used to adjust before the zero pressure difference point, and the pump is used to adjust after the zero pressure difference point;

The pump outlet check valve is set. When the pump starts, it is not necessary to close the pump outlet valve. The setting of the check valve can protect the pump; when the return water pressure is higher than the water supply pressure, it can prevent local short circuit caused by insufficient pump lift. loop, the situation where the user is not hot happens.

Bypass status of pipeline: When the entire pipeline is running, ensure that the bypass network of any main pipeline or branch pipeline is in a closed state.

Example 1: Please refer to Figures 5 and 6. Before the transformation of the distributed heating transmission and distribution system is adopted, in order to ensure sufficient resource head of the terminal heating network substation, the main circulating water pump of the heat source must be set with a higher head. The terrain of the main heat source is high, which will cause the pressure operation at the lower point of the terrain to be close to the design pressure of 1.6MPa, and the operating pressure of the entire pipeline network is relatively high.

Taking the transformation unit as an example, the pressure difference between the inlet and outlet of the first station of the heat source is 0.95MPa, the internal resistance loss of the heat source is considered to be 15mH2O, and the head of the main circulating water pump is 110m. The total circulating water volume of the heat source is 7000t/h, and the pump efficiency is calculated as 75%. Calculate the pump power:

Among them: N-pump shaft power kW;

M - pump head;

η - pump efficiency;

The centralized heat source single-group pump operation mode is adopted, and the total pump power is 2780Kw. If multiple pumps are used in parallel operation, the total pump power needs to be increased.

From the analysis of the water pressure diagram after the transformation, it can be concluded that after the transformation of the distributed heat supply and distribution system, the head of the main circulating water pump of the heat source can be greatly reduced, thereby reducing the installed capacity or operating power of the pump, and at the same time, the operating pressure of the entire heating network can be reduced. It is particularly important to improve the safety of pipeline network operation at low terrain.

The pressure difference between the inlet and outlet of the first station of the power plant is 0.3MPa, considering the resistance loss in the station of 15mH2O, so the lift of the main heat source circulating water pump is 45m, the circulating flow remains unchanged at 7000t/h, and the power of the main circulating water pump of the power plant is 1150KW.

The total installed power of the water pump of the distributed heating transmission and distribution system:

Through GeoPipe software simulation calculation, the capital pressure of each heating network substation is determined, and the total installed power of each distributed water pump is calculated to be 790kW.

In summary, after the implementation of the renovation, the total power of the heat network water pump is reduced from 2780KW to 1940KW, a decrease of 30%. The operating pressure of the pipe network is reduced by 0.3MPa.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention; the terms "first", "second", "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, and unless otherwise Clearly stipulated and defined, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or a Electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (9)

1. a kind of operation method about the hydraulic balance of heating pipe network, it is characterized in that: comprise the establishment of a network distributed heating transmission and distribution system; the whole network distributed transmission and distribution scheme; The establishment of the primary network distributed heat supply and distribution system includes: determination of zero pressure point; analysis of hydraulic working conditions of the heat supply system; operation adjustment; The whole network distributed transmission and distribution scheme includes: determination of zero pressure point; analysis of hydraulic working conditions of heating system; operation adjustment; determination of distributed transmission and distribution system scheme; design principles of distributed transmission and distribution system; The operation method about the hydraulic balance of the heating pipe network is composed of a distributed circulating water pump, a wireless pressure sensor, a remote transmission system, and a remote data management system. The remote transmission system uses the operator's 4G network, highly reliable LORA technology and Based on the fieldbus technology of in-station control, the data information of all control equipment and sensing equipment is collected by wire or wireless, and then the data is sent to the monitoring platform through GPRS, 3G, 4G, VPN or broadband, etc., and the remote data management system collects The data information of all cells in the area is analyzed, processed, stored and displayed. The host computer system of the remote data management system adopts B/S structure or C/S structure, all data is stored in the database system, and the data display is in the form of web pages, which are visually displayed with various graphics and curves, and can be displayed on other computers without Under the condition of installing any software, log in to the system directly through the browser, and view the relevant data with the corresponding user name and password. 2. A method for operating the hydraulic balance of a heating pipe network according to claim 1, characterized in that: the determination of the zero pressure point in the establishment of the primary network distributed heat supply and distribution system is specifically: In the water pressure diagram of the heat supply and distribution system, there is an intersection between the water supply pressure line and the return water pressure line of the main line, and the water supply pressure after the intersection is lower than the corresponding return water pressure. 3. A kind of operation method about the hydraulic balance of heating pipe network according to claim 1, it is characterized in that: the hydraulic condition analysis of the heating system in the establishment of the primary network distributed heat supply and distribution system is specifically: The distributed water pump is selected according to the circulating flow and head it undertakes. The flow is determined according to the heating area and heat index that the pump undertakes. Resistance is ok. 4. An operation method for hydraulic balance of heating pipe network according to claim 1, characterized in that: the operation adjustment during the establishment of the primary network distributed heat supply and distribution system is specifically: research and development of advanced technology based on water pump frequency conversion The automatic control system with speed regulation and optimized operation ensures the stable and efficient operation of the distributed heating and distribution system. 5. A method for operating the hydraulic balance of a heating pipe network according to claim 1, characterized in that: the determination of the zero pressure point in the distributed transmission and distribution scheme of the whole network is specifically: a network distributed transmission and distribution system Among them, the heat source main circulating water pump only undertakes the heat medium circulation inside the heat source, and the external circulating flow is provided by the distributed user pump, or it can be selected in the middle of the pipe network or other parts according to the needs. 6. A method for operating the hydraulic balance of a heating pipe network according to claim 1, wherein the analysis of the hydraulic working conditions of the heating system in the distributed transmission and distribution scheme of the whole network is as follows: a distributed water pump The selection of the type needs to determine its flow and head, the flow is determined according to the user's thermal index and area, the head is based on the zero pressure point, and the pressure loss of the main line and branch lines is determined. 7 . The method for operating the hydraulic balance of the heating pipe network according to claim 1 , wherein the operation adjustment in the distributed transmission and distribution scheme of the whole network is specifically: during the heating adjustment process of the primary network, 8 . According to the different outdoor temperature, the method of quality and adjustment is usually adopted. 8. A method for operating the hydraulic balance of a heating pipe network according to claim 1, characterized in that: the determination of the distributed transmission and distribution system scheme in the whole network distributed transmission and distribution scheme is specifically: using Geopipe hydraulic The calculation software carries out the modeling and simulation calculation of the pipeline network, and through the simulation analysis of multiple working conditions, the selection parameters of the pump are determined. According to Trangen's law:

Among them: G _i - the flow rate of each pipe section of the heating system, t/h; ΔH _i is the pressure drop loss of each pipe section of the heating system; η - pump efficiency; N _{0 -} the theoretical total power of the circulating water pump calculated by Trangen's law, kW; N The total power of the circulating water pump, Kw. 9. A method for operating the hydraulic balance of a heating pipe network according to claim 1, characterized in that: the design principle of the distributed transmission and distribution system in the distributed transmission and distribution scheme of the whole network is specifically: Selection: The selection of the flow and head of the distributed water pump should meet the requirements of various working conditions; Pump outlet valve setting: In the combined operation of variable frequency and multi-pump, the working characteristic curve of the pump and the resistance curve of the pipe network also change at any time. In the actual operation process, it is necessary to grasp the change of the working point of the pump in time, and take necessary control measures; Check valve settings; Bypass status of pipeline: When the entire pipeline is running, ensure that the bypass network of any main pipeline or branch pipeline is in a closed state.

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