Distributed intelligent heat supply network system

Abstract

The invention relates to the technical field of heat supply network systems, and discloses a distributed intelligent heat supply network system, which comprises a heat source pipe network, an urban main pipe network, a user main pipe network, valves, heat users, instruments, heat sources, controllers and frequency converters, and is characterized in that the heat source pipe network is connected with the heat sources and the urban main pipe network, the urban main pipe network is connected with the user main pipe network, and the valves are connected with the heat sources; the user main pipe network is connected with the heat users and the city main pipe network, and the valves are connected with the heat source pipe network, the city main pipe network and the user main pipe network. By adjusting the frequency converters at the heat users, the heat supply requirements of the heat users are met, and on-demand heat supply is truly achieved. The hydraulic imbalance problem of the system is eliminated, the heat supply efficiency is improved, and the heat supply quality is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of heating network systems, and in particular to a distributed intelligent heating network system. Background Art

[0002] With the rapid development of society, people's requirements for a better life are getting higher and higher, and heat users have higher and higher requirements for perceived temperature. Heating is gradually changing from standard heating to comfortable heating. This will also gradually increase the requirements for heating facilities and equipment.

[0003] In order to improve the safety and reliability of the heating network, many experts and scholars have proposed a ring heating network. However, due to unfavorable factors such as variable operating conditions and difficulty in system adjustment during operation, there are different degrees of isolation and decoupling operation in the actual operation process, which does not achieve the investment and construction purpose of the ring network. In order to give full play to the advantages of the ring network, a distributed intelligent heating network system is proposed. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a distributed intelligent heating network system to solve the problems raised in the above background technology.

[0006] (II) Technical solution

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a distributed intelligent heating network system, comprising a heat source network, a city main network, a user main network, a valve, a heat user, an instrument, a heat source, a controller and a frequency converter, wherein the heat source network is connected to the heat source and the city main network, the city main network is connected to the user main network, the user main network is connected to the heat user and the city main network, the valve is connected to the heat source network, the city main network and the user main network, the instrument and the frequency converter are all connected to the heat user through the controller, the heat source network connects the heat source and the city main network, transports high-temperature water at the heat source to the city main network, and transports low-temperature water from the city main network to the heat source for heating to increase the temperature, the city main network stores and transports the heat to each heat user main network, the user main network is used to link the heat user with the city main network, and transports the heat from the city main network to the heat user side, the valve is used to realize the switching of the operation and maintenance of the network, and the heat user is a group that needs heat, and their production and living needs are met by supplying their heat.

[0008] Preferably, the instrumentation includes a pressure sensor PT and a temperature sensor TT, the frequency converter is a water pump frequency converter, the instrumentation collects and transmits the operating parameters of the heating system, and ensures the heating capacity of the smart heating network system by adjusting the operating parameters. The heat source is the place where heat is produced. The controller analyzes and calculates the operating parameters, outdoor parameters, and heat user parameters, and sends the calculation results in the form of instructions to the system control device. The frequency converter is used to adjust the power of the water pump so that the circulation volume of the water pump is close to the ideal circulation volume of the smart heating network system.

[0009] (III) Beneficial effects

[0010] Compared with the prior art, the present invention provides a distributed intelligent heating network system, which has the following beneficial effects:

[0011] 1. The present invention satisfies the heating demand of heat users by adjusting the frequency converter at the heat users, truly realizes heating on demand, eliminates the problem of hydraulic imbalance in the system, improves heating efficiency, and ensures heating quality;

[0012] 2. The smart heating network system of the present invention can greatly reduce the operating pressure of the urban heating network system. When a fault occurs in the smart heating network, the fault point can be isolated through the valve of the smart heating network, reducing the affected area, improving the reliability of the system, and achieving the purpose of building a ring pipe network. While reducing the operating pressure, it will also greatly reduce the safety hazards of the urban heating network and improve the safety of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of a distributed intelligent variable frequency heating network system in a multi-heat source annular pipe network state of the present invention;

[0014] Figure 2 This is a quality control flow chart of the smart heating network system of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0016] Embodiment 1:

[0017] A distributed intelligent heating network system, please refer to Figure 1 and Figure 2, including a heat source network, a city main network, a user main network, a valve, a heat user, an instrument, a heat source, a controller and a frequency converter. The heat source network is connected to the heat source and the city main network, the city main network is connected to the user main network, the user main network is connected to the heat user and the city main network, the valve is connected to the heat source network, the city main network and the user main network, the instrument and the frequency converter are connected to the heat user through the controller, the heat source network connects the heat source and the city main network, transports high-temperature water at the heat source to the city main network, and transports low-temperature water from the city main network to the heat source for heating to increase the temperature, the city main network stores and transports the heat to each heat user main network, the user main network is used to link the heat user with the city main network, and transports the heat from the city main network to the heat user side, the valve is used to realize the switching of the operation and maintenance of the network, the heat user is a group that needs heat, and the production and living needs of the heat user are met by supplying their heat;

[0018] See also Figure 1 and Figure 2 The instrumentation includes a pressure sensor PT and a temperature sensor TT. The frequency converter is a water pump frequency converter. The instrumentation collects and transmits the operating parameters of the heating system. By adjusting the operating parameters, the heating capacity of the smart heating network system is guaranteed. The heat source is a place where heat is produced. The controller analyzes and calculates the operating parameters, outdoor parameters, and heat user parameters, and sends the calculation results to the system control device in the form of instructions. The frequency converter is used to adjust the power of the water pump to make the circulation volume of the water pump close to the ideal circulation volume of the smart heating network system.

[0019] Embodiment 2:

[0020] A distributed intelligent heating network system provided in Example 1 includes the following control methods:

[0021] Quality regulation (temperature regulation): By adjusting the temperature of the smart heating network system to ensure the heating capacity of the smart heating network system, the controller analyzes and calculates the collected real-time operating parameters. When the temperature of the smart heating network system cannot meet the heating needs of the heat users, the controller will send the instruction to increase the temperature of the smart heating network system to the heat source ABC. After receiving the controller's instruction, the heat source ABC will respond to the temperature increase in time. Through multiple similar analysis, calculation, instructions, and responses, the temperature of the smart heating network system is maintained within a reasonable temperature range;

[0022] Quantity regulation (circulation volume regulation): By adjusting the frequency conversion of the smart heating network system, the circulation volume of the smart heating network system reaches an ideal state. The controller analyzes and calculates the collected real-time operating parameters. When the circulation volume of heat user 5 cannot meet the heat demand, the controller will send an instruction to increase the circulation volume on the heat user side to the inverter at heat user 5. After receiving the controller instruction, the inverter at heat user 5 will make timely adjustments and responses. When the circulation volume at heat user 5 increases, the pressure of the city main network will decrease. When the pressure of the city main network decreases to the set value, the controller will send an instruction to increase the system pressure to the heat source. After receiving the pressure increase instruction, the heat source will respond to the pressure increase in time. Through multiple similar analysis, calculations, instructions, and responses, heat user 5 can reach an ideal heating state, and the pressure of the smart heating network system can be maintained within a reasonable range;

[0023] Quality coordination adjustment (temperature + circulation volume adjustment): By adjusting the operating temperature and circulation volume of the smart heating network system, the smart heating network system always maintains the required heating capacity. When the ideal heating state cannot be achieved by adjusting any of the above adjustment methods, the controller will combine the above two adjustment methods to analyze and calculate the accurate quality coordination adjustment instructions. The instructions will be sent to each adjustment device to adjust the system to the ideal state;

[0024] Indoor temperature compensation calculation: The smart heat network system collects, analyzes and calculates the indoor temperature of the heat user side, keeps the indoor temperature of the heat user side within the specified range, and reduces energy waste;

[0025] Outdoor temperature compensation calculation: With the rapid development of cities, urban heating networks are also growing. It takes at least three to five hours, and at most more than ten hours, for hot water to travel from the heat source to the heat user. In order to avoid the unreasonable phenomenon of "not being able to supply when needed, and not being able to use when not needed", and to keep the indoor temperature of heat users within a reasonable range, the smart heating network system collects the local weather forecast temperature, and performs compensation calculations 8-12 hours in advance based on the weather forecast temperature, so that the smart heating network system can be adjusted in advance according to the weather forecast temperature, ensuring that the heating capacity of the smart heating network system is sufficient, thus achieving a truly smart heating network adjustment system;

[0026] The relationship between the heating design thermal index (excluding pipe network and imbalance heat loss) is as follows:

[0027]

[0028] Where q d -Heating design thermal index, W / m 2 ;

[0029] q h ---Heat consumption index of buildings, W / m 2 ;

[0030] t in，d ---Indoor design temperature during heating period is 18℃;

[0031] t out ---Calculated outdoor temperature during heating period, ℃;

[0032] t in，a --- Average indoor temperature during heating period is 16℃;

[0033] t out，a --- Average outdoor temperature during heating period, ℃;

[0034] t d --- Natural temperature rise of indoor air caused by solar radiation and indoor free heat, ℃, generally 3-5℃, 3.8℃ for residential buildings;

[0035] The calculation formula for heating heat load is as follows:

[0036] Q=q d A×10 -6

[0037] Where Q-heating load, MW;

[0038] A-building heating area, m 2 ;

[0039] The basic formula for running adjustments:

[0040] When the hot water network is running in a stable state, if the heat loss along the pipe network is not considered, the heat supply of the network is equal to the heat released by the heat dissipation equipment of the heating user system, and it should also be equal to the heat load of the heating user. Assuming that the heating heat load is proportional to the change in the indoor and outdoor temperature difference, the basic formula for operation regulation can be obtained, that is,

[0041]

[0042] Or written as the calculation formula for supply and return water temperature:

[0043]

[0044] Δt′ s =0.5(t′ su +t′ re -2t′ in )

[0045] Δt′ j =t′ su -t′ re

[0046]

[0047] Where Δt′ s --- Design average calculated temperature difference of user radiator, ℃;

[0048] Δt′ j --- Design supply and return water temperature difference of secondary network, ℃;

[0049] Grel-relative flow ratio;

[0050] t su ---Water supply temperature, °C;

[0051] t re ---Return water temperature, °C;

[0052] t′ su --- Designed water supply temperature, °C;

[0053] t′ re ---Designed return water temperature, °C;

[0054] t in --Indoor heating design temperature is 18℃;

[0055] tout--a certain outdoor temperature, ℃;

[0056] t′ out ---Outdoor heating calculation temperature, ℃;

[0057] (You can substitute the weather forecast temperature into the formula for calculation);

[0058] b- The exponent value in the formula of the heat transfer coefficient K of the radiator. For commonly used radiators, b = 0.14 ~ 0.37;

[0059] Centralized adjustment method:

[0060] At the heat source (thermal power plant or heating boiler room), the supply and return water temperature and flow are adjusted according to the outdoor temperature. This is called centralized operation regulation, which is divided into four types: quality regulation, quantity regulation, quality regulation with staged flow change, and intermittent regulation:

[0061] 1. Quality adjustment

[0062] Throughout the heating season, the system flow rate maintains the design flow rate unchanged, that is, Grel = 1.0. As the outdoor temperature tout changes, only the water supply temperature is adjusted, which is called centralized mass regulation.

[0063] Substituting Grel = 1.0 into the basic adjustment formula, we get the concentrated mass adjustment formula:

[0064]

[0065] In formula (15-4) and formula (15-5), the design supply and return water temperatures are known values, and the local outdoor heating calculation temperature is also a known value. This formula can be used to calculate the supply and return water temperatures required for a certain area at any outdoor calculation temperature;

[0066] 2. Quantity adjustment:

[0067] During the entire heating season, the water supply temperature remains constant at the design value, i.e., t su =t′ su , adjust the heating system flow G and return water temperature t re , to adapt to the change of heat load, this kind of regulation is called centralized regulation, and its regulation formula is:

[0068]

[0069] The advantage of centralized quantity regulation is that it saves electricity, but the disadvantage is that the operation is complicated and requires a stepless speed regulation heat network circulating water pump. Currently, the price of this type of water pump is relatively high. Secondly, if the heat network flow is too small, it will have a certain impact on the user's flow distribution, which is easy to cause vertical thermal imbalance for the user.

[0070] 3. Change the quality regulation of flow in stages:

[0071] Since continuous changes in flow are difficult to control, simple centralized quantity regulation is generally not used, but quality regulation that changes the flow in stages. That is, the entire heating period is divided into several stages according to the outdoor temperature. A larger flow rate is used in the stage with lower outdoor temperature, and a smaller flow rate is used in the stage with higher outdoor temperature. However, in each stage, the flow rate is kept fixed and quality regulation that changes the water supply temperature is used, so that the relative flow rate G rel =φ=constant, and substitute it into the basic formula of operation regulation, we can get the formula of staged variable flow regulation, that is:

[0072]

[0073] In formula (15-8) and formula (15-9), the parameters with superscript "'" are under design conditions, and those without superscript are under any outdoor temperature. in =t in ′=18℃, so it is used to replace m in operation adjustment;

[0074] See also Figure 2 , quality adjustment control process:

[0075] (1) The controller collects indoor and outdoor temperatures and the heating temperature of the heat exchange station through control lines 1, 2, and 4, and calculates the ideal indoor temperature under the current outdoor temperature through the controller. The calculated value is compared with the current collected value. The comparison result is converted into a temperature increase or decrease instruction, which is sent to the heat source through control line 3. The heat source will adjust according to the instruction. As the adjustment cycle continues, the control value will be infinitely close to the calculated value.

[0076] (2) The controller will collect weather forecast temperature and heat source temperature 8-12 hours in advance through control lines 5 and 3. The controller will calculate the reasonable temperature range of the city main network and send the range command to the heat source through control line 3. The heat source will be adjusted step by step in advance according to the controller's instructions to avoid excessive thermal stress in the pipe network in a short period of time due to too fast adjustment, which will damage the city heating pipe network system.

[0077] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0078] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A distributed intelligent heat network system, comprising a heat source network, a city main network, a user main network, valves, heat users, instruments, heat sources, controllers and frequency converters, characterized in that: The heat source pipeline is connected to the heat source and the city main network, the city main network is connected to the user main network, the user main network is connected to the heat user and the city main network, the valve is connected to the heat source pipeline, the city main network and the user main network, and the instruments and converters are connected to the heat users through controllers.

2. A distributed intelligent heating network system according to claim 1, characterized in that: The instrumentation includes a pressure sensor PT and a temperature sensor TT, and the frequency converter is a water pump frequency converter.

3. A control method for a distributed intelligent heating network system according to any one of claims 1-2, characterized in that: The following control methods are included: Quality regulation: By adjusting the temperature of the smart heating network system, the heating capacity of the smart heating network system is guaranteed. The controller analyzes and calculates the collected real-time operating parameters. When the temperature of the smart heating network system cannot meet the heating needs of the heat users, the controller will send an instruction to increase the temperature of the smart heating network system to the heat source ABC. After receiving the controller instruction, the heat source ABC responds by raising the temperature. Quantity adjustment: By adjusting the frequency conversion of the smart heating network system, the circulation volume of the smart heating network system reaches the ideal state. The controller analyzes and calculates the collected real-time operating parameters. When the circulation volume of the heat user cannot meet the heat demand, the controller will send the instruction to increase the circulation volume on the heat user side to the inverter at the heat user. After receiving the controller instruction, the inverter at the heat user will make timely adjustments and responses. When the circulation volume at the heat user increases, the pressure of the city main network will decrease. When the pressure of the city main network drops to the set value, the controller will send the instruction to increase the system pressure to the heat source. After receiving the pressure increase instruction, the heat source will respond with a pressure increase; Quality coordination adjustment: By adjusting the operating temperature and circulation volume of the smart heating network system, the smart heating network system always maintains the required heating capacity. When the ideal heating state cannot be achieved by adjusting any of the above adjustment methods, the controller will combine the two adjustment methods of quality adjustment and quantity adjustment, analyze and calculate the accurate quality coordination adjustment instructions; and send the instructions to each adjustment device to adjust the system to the ideal state.

Images