A method and system for operating a multi-stage pump for long-distance heating

Abstract

This invention belongs to the technical field of heating equipment, specifically relating to a method and system for operating multi-stage pumps for long-distance heating. It includes the following steps: S1, calculating the total heat load demand Q based on the heat load requirement; S2, calculating the supply and return water temperature difference ΔT in the pipeline network; S3, calculating the target flow rate m required by the pipeline network; S4, establishing and running a digital twin model of the pipeline network with functions for resistance calculation, frequency setting, head calculation, and power consumption calculation; S5, setting the frequency of each pump station separately, and calculating the head, total pipeline resistance, power consumption, total head, and total power consumption of each pump station; S6, verifying the rationality of the scheme; S7, evaluating the economic efficiency of the scheme. Existing technologies lack consideration for the operating efficiency of different pump sets, the overall power consumption performance of the pump sets, and the power consumption methods of the pump sets. They fail to reduce the overall energy consumption of the pump sets by matching the pressure boosting capabilities of each stage of the multi-stage pump set, thus having certain limitations in terms of economic efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of heating equipment, specifically relating to a method and system for operating a multi-stage pump for long-distance heating. Background Technology

[0002] Long-distance heating is a highly competitive approach to clean and intensive urban heating, effectively utilizing the heating capacity of large-scale combined heat and power (CHP) units within and around cities while reducing the need for scattered small boilers. Currently, several long-distance heating systems have been built and put into operation in northern China, including the Taikoo Long-Distance Heating Project, the Shijiazhuang Long-Distance Heating Project, and the Yimin Long-Distance Heating Project in the Hulunbuir high-altitude cold region. To achieve the long-distance transport of hot water, long-distance heating typically involves multiple booster pump sets. Considering factors such as terrain elevation and transport distance, each pump set differs in power consumption, head performance, and efficiency. By comprehensively considering the pump's efficient operating range and power consumption patterns, the operational economy of multi-stage pump sets in long-distance heating systems can be effectively improved, thus increasing efficiency.

[0003] Currently, the operation mode of multi-stage pump sets is usually determined by the heating network dispatching and operation personnel. In order to ensure the overall pressure and flow stability of the system, the heating network dispatching personnel usually start multiple booster pump sets under most operating flow conditions. This operation mode can ensure that the pressure before and after each pump set tends to be balanced, the pressure rise of a single pump set is small, the amount of operation during the operation adjustment process is reduced, and the water hammer pressure impact caused by pump failure is reduced.

[0004] Multistage pump operation is generally based on safety considerations, operating multiple pump sets to maintain system stability. However, it lacks consideration for the operating efficiency of different pump sets, the overall power consumption of the pump sets, and the power consumption methods of the pump sets. It fails to reduce the overall energy consumption of the pump sets by matching the pressure boosting capabilities of each stage of the multistage pump set, which has certain limitations in terms of economic efficiency. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for operating a multi-stage pump for long-distance heating, so as to solve the problem in the prior art that the overall energy consumption of the pump group cannot be reduced by matching the pressure boosting capacity of each stage of the multi-stage pump group.

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

[0007] A method for operating a multi-stage pump for long-distance heating includes the following steps:

[0008] S1. Calculate the total heat load demand based on the heat load requirement;

[0009] S2. Set the water supply temperature of the pipeline network, and calculate the temperature difference between the supply and return water of the pipeline network based on the supply and return water temperatures of the pipeline network.

[0010] S3. Calculate the target flow rate required by the pipeline network based on the total heat load demand and the temperature difference between the supply and return water in the pipeline network;

[0011] S4. Establish and run a digital twin model of the pipeline network. The digital twin model of the pipeline network consists of a theoretical calculation module and an identification and correction module, and has functions for resistance calculation, frequency setting, head calculation and power consumption calculation.

[0012] S5. Based on the target flow rate and the digital twin model of the pipeline network, set the frequency of each pump station, and calculate the head, total pipeline resistance, power consumption, total head, and total power consumption of each pump station.

[0013] S6. Verify the rationality of the scheme, that is, check whether the condition that the total resistance of the pipeline network is equal to the total head of the pumping station is met.

[0014] S7. Evaluate the economics of the solution, i.e., check whether it achieves the minimum or most reasonable power consumption cost;

[0015] S8. Develop a multi-stage pump economic dispatch plan and output it to the heating network dispatch personnel.

[0016] Optionally, the identification and correction module corrects the parameters in the theoretical calculation module using actual operating data.

[0017] Optionally, in step S5, the resistance-flow rate calculation formula for the segmented resistance between each pumping station is as follows:

[0018] ΔP n =a1Q 2 +a2Q+a3

[0019] The total resistance of the pipeline network is obtained from the segmented resistances between the pumping stations in the pipeline network:

[0020] ΔP 总 =∑ΔP n

[0021] Where n is the segment number between each pump station; a1, a2, and a3 are parameters determined by the identification and correction module; Q is the total heat load demand; ΔP n The resistance is divided into sections between each pumping station.

[0022] Optionally, in step S5, the head-flow rate calculation formula is:

[0023] ΔH n =a1m 2 +a2m+a3

[0024] The total head of the pumping station is equal to the sum of the heads of all the individual pumping stations:

[0025] ΔH 总 =∑ΔH n

[0026] Where n is the pump station number, a1, a2, and a3 are parameters determined by the identification and correction module; m is the target flow rate; ΔH n To determine the head of each pumping station.

[0027] Optionally, in step S5, the power consumption formula is:

[0028] E n =QgΔH / 3.6η

[0029] Total power consumption of the pumping station E 总 The sum of the power consumption of each pumping station:

[0030] E 总 =∑E n

[0031] Where n is the pump station number; Q is the target flow rate; g is the gravitational acceleration; ΔH is the head of each pump station; η is the pump efficiency; E n This consumes electricity for each pumping station.

[0032] Optionally, the pipeline network digital twin model also has flow calculation and temperature calculation functions.

[0033] Optionally, the water supply temperature T of the pipeline network g The return water temperature T of the pipeline network is a value between 65℃ and 95℃. h It is a value between 40℃ and 60℃.

[0034] Optionally, in step S7, the step of evaluating the economic efficiency of the scheme includes:

[0035] S71. Calculate the operating cost of each pumping station based on its power consumption and electricity price.

[0036] S72. Add up the operating costs of each pumping station to obtain the total operating cost;

[0037] S73. Compare the total operating costs under different schemes and select the scheme with the minimum or most reasonable cost.

[0038] Optionally, in step S8, the step of formulating a multi-stage pump economic dispatch plan and outputting it to the heating network dispatcher includes:

[0039] S81. Display the frequency, head, power consumption and other information of each pumping station on the screen in the form of a table or graph.

[0040] S82. Send the multi-stage pump economic dispatch plan to the heating network dispatcher in text or voice format.

[0041] An economical operating system for long-distance heating multi-stage pumps includes the following components:

[0042] The heat load demand calculation module provides the total heat load demand.

[0043] The pipeline heating setting module is used to set the pipeline water supply temperature, and the pipeline supply and return temperature difference calculation module calculates the pipeline supply and return water temperature difference based on the pipeline water supply temperature and the pipeline return water temperature.

[0044] The target flow calculation module is used to calculate the target flow required by the pipeline network based on the total heat load demand and the temperature difference between the supply and return water in the pipeline network.

[0045] A pipeline network digital twin model, which consists of a theoretical calculation module and an identification and correction module. The theoretical calculation module includes a pipeline network total resistance calculation module, a pump station frequency setting module, a pump station head calculation module, and a pump station power consumption calculation module.

[0046] Based on the target flow rate m and the digital twin model of the pipeline network, the frequency of each pump station is set, and the head, power consumption of each pump station, as well as the total resistance, total head, and total power consumption of the pipeline network are calculated.

[0047] The scheme rationality verification module is used to verify the rationality of the scheme and check whether the condition that the total resistance of the pipeline network equals the total head of the pumping station is met.

[0048] The scheme economic evaluation module is used to evaluate the economics of the scheme and check whether the minimum or most reasonable power consumption cost is achieved.

[0049] The multi-stage pump economic dispatch scheme formulation module is used to formulate multi-stage pump economic dispatch schemes and output them to the heating network dispatchers.

[0050] The beneficial effects of this invention are as follows:

[0051] This invention provides a method and system for operating multi-stage pumps in long-distance heating systems. For long-distance heating systems containing multiple booster pump stations, starting from the heat load demand, it calculates the output of each pump group and formulates an optimized operation scheme for the multi-stage pump groups. Combined with the actual system, this reduces the power consumption cost of the long-distance heating system and creates economic benefits. Attached Figure Description

[0052] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0053] Figure 1 This is a schematic diagram of an embodiment of a multi-stage pump operation method and system for long-distance heating according to the present invention.

[0054] Figure 2 This diagram illustrates a long-distance heating system with multiple pump stations, representing an embodiment of a multi-stage pump operation method and system for long-distance heating according to the present invention.

[0055] Figure 3 This is a comparison diagram showing the optimization of a long-distance heating multi-stage pump operation method and system embodiment under low load.

[0056] Figure 4 This is a comparison diagram showing the optimization of a long-distance heating multi-stage pump operation method and system embodiment under high load.

[0057] The modules are as follows: 1-Heat load demand calculation module, 2-Pipeline network temperature setting module, 3-Pipeline network supply and return temperature difference calculation module, 4-Target flow calculation module, 5-Theoretical calculation module, 6-Identification and correction module, 7-Pipeline network digital twin model, 8-Pipeline network total resistance calculation module, 9-Pump station frequency setting module, 10-Pump station head calculation module, 11-Pump station power consumption calculation module, 12-Scheme rationality verification module, 13-Scheme economic evaluation module, and 14-Multi-stage pump economic dispatch scheme formulation module. Detailed Implementation

[0058] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0059] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0060] like Figure 1 As shown, an embodiment of a long-distance heating multi-stage pump operation method includes the following steps:

[0061] S1. Calculate the total heat load demand Q based on the heat load requirement;

[0062] S2, Set the water supply temperature of the pipe network T g And according to the water supply temperature T of the pipeline network g and the return water temperature T of the pipe network h Calculate the supply and return water temperature difference ΔT in the pipe network;

[0063] S3. Calculate the target flow rate m required by the pipeline network based on the total heat load demand Q and the supply and return water temperature difference ΔT.

[0064] S4. Establish and run the pipeline network digital twin model 7. The pipeline network digital twin model 7 consists of a theoretical calculation module 5 and an identification and correction module 6, and has functions for resistance calculation, frequency setting, head calculation and power consumption calculation.

[0065] S5. Based on the target flow rate m and the digital twin model 7 of the pipeline network, set the frequency of each pump station, and calculate the head, total pipeline resistance, power consumption, total head, and total power consumption of each pump station.

[0066] S6. Verify the rationality of the scheme, that is, check whether the condition that the total resistance of the pipeline network is equal to the total head of the pumping station is met.

[0067] S7. Evaluate the economics of the solution, i.e., check whether it achieves the minimum or most reasonable power consumption cost;

[0068] S8. Develop a multi-stage pump economic dispatch plan and output it to the heating network dispatch personnel.

[0069] Specifically, the heat load demand in S1 refers to the amount of heat required to maintain room thermal balance per unit time. The total heat load demand can be calculated using methods such as the unit index method, the demand factor method, and the utilization factor method.

[0070] It should be noted that heat load demand refers to the urban heat index, with units of W / m². 2 Multiplying this by the heating area equals the total heat load demand, in W.

[0071] In step S2, the calculation formula can be: ΔT = T g -T h ΔT is the temperature difference between the supply and return water in the pipe network, T g T represents the water supply temperature of the pipeline network. h This refers to the return water temperature of the pipeline network.

[0072] In step S3, the calculation formula can be:

[0073] In step S4, specifically, the pipeline network digital twin model 7 is a calculation model. The pipeline network digital twin model 7 consists of a theoretical calculation module 5 and an identification and correction module 6. The theoretical calculation module 5 can have resistance calculation function, frequency setting function, head calculation function and power consumption calculation function. The theoretical calculation module 5 can also include a pipeline network total resistance calculation module 8, a pump station frequency setting module 9, a pump station head calculation module 10 and a pump station power consumption calculation module 11; the functions are realized through modules.

[0074] Each pumping station corresponds to a pumping station frequency setting module 9, a pumping station head calculation module 10, and a pumping station power consumption calculation module 11. The scheme is to set the frequency of each pumping station and formulate an operation plan for multi-stage pump groups by setting different frequencies for each pumping station.

[0075] In the preferred embodiment, step S6 can verify the rationality of the scheme through the scheme rationality verification module 12 or manually. It can determine whether the total resistance of the pipeline network is equal to the total head of the pumping station at different frequencies. If the total resistance of the pipeline network is equal to the total head of the pumping station, the scheme can be used normally. If the total resistance of the pipeline network is not equal to the total head of the pumping station, the scheme is unusable. The frequency of each pumping station is reset, the calculation is recalculated, and the rationality of the scheme is re-verified.

[0076] In step S7, multiple available schemes are obtained. The scheme economic evaluation module 13 can be used to check whether the minimum or most reasonable power consumption cost is achieved, or the economics of the scheme can be evaluated manually. The above multiple schemes are compared, and the scheme with the minimum or most reasonable power consumption cost is selected.

[0077] In step S8, a multi-stage pump economic dispatch plan is formulated based on the selected scheme and output to the heating network dispatch personnel.

[0078] As a preferred example, the identification and correction module 6 corrects the parameters in the theoretical calculation module 5 using actual operating data.

[0079] As a specific example of the above embodiment, in step S5, the resistance-flow rate calculation formula for the segmented resistance between each pumping station is as follows:

[0080] ΔP n =a1Q 2 +a2Q+a3

[0081] The total resistance of the pipeline network is obtained from the segmented resistances between the pumping stations in the pipeline network:

[0082] ΔP 总 =∑ΔP n

[0083] Where n is the segment number between each pump station; a1, a2, and a3 are the parameters determined by the identification and correction module 6; Q is the total heat load demand; ΔP n The resistance is divided into sections between each pumping station.

[0084] As a specific example, in step S5, the head-flow rate calculation formula is:

[0085] ΔH n =a1m 2 +a2m+a3

[0086] The total head of the pumping station is equal to the sum of the heads of all the individual pumping stations:

[0087] ΔH 总 =∑ΔH n

[0088] Where n is the pump station number, a1, a2, and a3 are parameters determined by the identification and correction module 6; m is the target flow rate; ΔH n To determine the head of each pumping station.

[0089] As a specific example of the above embodiment, in step S5, the power consumption formula is:

[0090] E n =QgΔH / 3.6η

[0091] Total power consumption of the pumping station E 总 The sum of the power consumption of each pumping station:

[0092] E 总 =∑E n

[0093] Where n is the pump station number; Q is the target flow rate; g is the gravitational acceleration; ΔH is the head of each pump station; η is the pump efficiency; E n This consumes electricity for each pumping station.

[0094] As a preferred example, the pipeline digital twin model 7 also has flow calculation and temperature calculation functions.

[0095] As a specific example, the water supply temperature T in the pipe network g It can be a value between 65℃ and 95℃, and the return water temperature T in the pipe network. h The temperature is between 40°C and 60°C.

[0096] As a specific example, step S7, which involves evaluating the economics of the proposed solution, further includes:

[0097] S71. Calculate the operating cost of each pumping station based on its power consumption and electricity price.

[0098] S72. Add up the operating costs of each pumping station to obtain the total operating cost;

[0099] S73. Compare the total operating costs under different schemes and select the scheme with the minimum or most reasonable cost.

[0100] As a specific example, step S8, which involves formulating a multi-stage pump economic dispatch plan and outputting it to the heating network dispatchers, also includes:

[0101] S81. Display the frequency, head, power consumption and other information of each pumping station on the screen in the form of a table or graph.

[0102] S82. Send the multi-stage pump economic dispatch plan to the heating network dispatcher in text or voice format.

[0103] As another embodiment, a long-distance heating multi-stage pump economical operation system includes the following components:

[0104] Heat load demand calculation module 1 provides the total heat load demand;

[0105] Pipeline heating setting module 2 is used to set the pipeline water supply temperature, and pipeline supply and return temperature difference calculation module 3 calculates the pipeline supply and return water temperature difference based on the pipeline water supply temperature and pipeline return water temperature.

[0106] Target flow calculation module 4 is used to calculate the target flow required by the pipeline network based on the total heat load demand and the temperature difference between the supply and return water of the pipeline network;

[0107] The pipeline network digital twin model 7 consists of a theoretical calculation module 5 and an identification and correction module 6. The theoretical calculation module 5 includes a pipeline network total resistance calculation module 8, a pump station frequency setting module 9, a pump station head calculation module 10, and a pump station power consumption calculation module 11.

[0108] Based on the target flow rate m and the digital twin model 7 of the pipeline network, the frequency of each pump station is set, and the head, power consumption of each pump station, as well as the total resistance, total head, and total power consumption of the pipeline network are calculated.

[0109] The scheme rationality verification module 12 is used to verify the rationality of the scheme and check whether the condition that the total resistance of the pipeline network is equal to the total head of the pumping station is met.

[0110] The scheme economic evaluation module 13 is used to evaluate the economics of the scheme and check whether the minimum or most reasonable power consumption cost is achieved.

[0111] The multi-stage pump economic dispatch scheme formulation module 14 is used to formulate multi-stage pump economic dispatch schemes and output them to the heating network dispatchers.

[0112] like Figure 2 As shown, taking a long-distance heating project as an example, the long-distance heating system includes six pumping stations. The first station uses plant power, while the remaining five pumping stations use purchased power. The cost of plant power is significantly lower than the cost of purchased power. The pump operation mode is optimized under both low-load and high-load flow conditions. Using the above-mentioned economical operation method for multi-stage pumps in long-distance heating, two reasonable schemes can be developed: the first is to operate only the first station pumping unit, and the second is to operate both the first station pumping unit and the pressure-reducing station pumping unit. The water pressure diagrams and power consumption for the two operation modes are shown below. Figure 3 As shown, by comparing different power consumption structures, it can be found that activating only the primary pump unit can significantly reduce the use of externally purchased electricity, thereby lowering electricity costs. Under high load flow, two reasonable operating schemes can also be formulated: the first is for all pump stations to operate at the same frequency, and the second is for the primary pump station to operate at a high frequency while other pump stations operate at a low frequency. The water pressure diagrams and power consumption for the two operating modes are shown below. Figure 4As shown, by comparing different power consumption structures, it can be found that only using the first station at high frequency and other pump stations at low frequency can effectively reduce the use of purchased electricity, thereby reducing electricity costs.

[0113] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A method for operating a multi-stage pump for long-distance heating, characterized in that: Includes the following steps: S1. Calculate the total heat load demand based on the heat load requirement; S2. Set the water supply temperature of the pipeline network, and calculate the temperature difference between the supply and return water of the pipeline network based on the supply and return water temperatures of the pipeline network. S3. Calculate the target flow rate required by the pipeline network based on the total heat load demand and the temperature difference between the supply and return water in the pipeline network; S4. Establish and run a pipeline network digital twin model (7). The pipeline network digital twin model (7) consists of a theoretical calculation module (5) and an identification and correction module (6), and has resistance calculation function, frequency setting function, head calculation function and power consumption calculation function. The identification and correction module (6) corrects the parameters in the theoretical calculation module (5) through actual operating data. The pipeline network digital twin model (7) also has flow calculation function and temperature calculation function. S5. Based on the target flow rate and the digital twin model of the pipeline network (7), set the frequency of each pump station respectively, and calculate the head, total resistance of the pipeline network, power consumption, total head and total power consumption of each pump station respectively, so as to obtain the scheme for the operation of the multi-stage pump group. S6. Verify the rationality of the scheme and check whether it meets the condition that the total resistance of the pipeline network is equal to the total head of the pumping station. S7. If the total resistance of the pipeline network equals the total head of the pumping station, evaluate the economic efficiency of the scheme and check whether it achieves the minimum or most reasonable power consumption cost. The steps for evaluating the economic efficiency of the scheme include: S71. Calculate the operating cost of each pumping station based on its power consumption and electricity price. S72. Add up the operating costs of each pumping station to obtain the total operating cost; S73. Compare the total operating costs under different schemes and select the scheme with the minimum or most reasonable cost. S8. If the solution achieves the minimum or most reasonable power consumption cost, formulate a multi-stage pump economic dispatch plan and output it to the heating network dispatch personnel.

2. The method for operating a multi-stage pump for long-distance heating according to claim 1, characterized in that: In step S5, the formula for calculating the resistance-flow rate of the segmented resistance between each pumping station is as follows: The total resistance of the pipeline network is obtained from the segmented resistances between the pumping stations in the pipeline network: Where n is the segment number between each pumping station; , , The parameters determined by the identification and correction module (6); Total heat load demand; The resistance is divided into sections between each pumping station.

3. The method for operating a multi-stage pump for long-distance heating according to claim 1, characterized in that: In step S5, the head-flow rate calculation formula is: The total head of the pumping station is equal to the sum of the heads of all the individual pumping stations: Where n is the number of each pumping station , , The parameters determined by the identification and correction module (6); For target traffic; To determine the head of each pumping station.

4. The method for operating a multi-stage pump for long-distance heating according to claim 1, characterized in that: In step S5, the power consumption formula is: Total power consumption of the pumping station The sum of the power consumption of each pumping station: Where n is the number of each pump station; For target traffic; It is the acceleration due to gravity; To determine the head of each pumping station; For water pump efficiency; This consumes electricity for each pumping station.

5. The method for operating a multi-stage pump for long-distance heating according to claim 1, characterized in that: The water supply temperature of the pipeline network The return water temperature of the pipe network is a value between 65°C and 95°C. It is a value between 40°C and 60°C.

6. The method for operating a multi-stage pump for long-distance heating according to claim 1, characterized in that: Step S8, the step of formulating a multi-stage pump economic dispatch plan and outputting it to the heating network dispatching personnel, includes: S81. Display the frequency, head, power consumption and other information of each pumping station on the screen in the form of a table or graph. S82. Send the multi-stage pump economic dispatch plan to the heating network dispatcher in text or voice format.

7. An economical operation system for long-distance heating multi-stage pumps, characterized in that: Includes the following parts: The heat load demand calculation module (1) provides the total heat load demand; The pipeline heating setting module (2) is used to set the pipeline water supply temperature, and the pipeline supply and return temperature difference calculation module (3) calculates the pipeline supply and return water temperature difference based on the pipeline water supply temperature and the pipeline return water temperature. The target flow calculation module (4) is used to calculate the target flow required by the pipeline network based on the total heat load demand and the temperature difference between the supply and return water of the pipeline network. The pipeline network digital twin model (7) consists of a theoretical calculation module (5) and an identification and correction module (6). The theoretical calculation module (5) includes a pipeline network total resistance calculation module (8), a pump station frequency setting module (9), a pump station head calculation module (10), and a pump station power consumption calculation module (11). Based on target traffic The pipeline network digital twin model (7) sets the frequency of each pump station and calculates the head, power consumption of each pump station, and the total resistance, total head, and total power consumption of the pipeline network. The identification and correction module (6) corrects the parameters in the theoretical calculation module (5) using actual operating data. The pipeline network digital twin model (7) also has flow calculation and temperature calculation functions. The scheme rationality verification module (12) is used to verify the rationality of the scheme and check whether the scheme meets the condition that the total resistance of the pipeline network is equal to the total head of the pumping station. The scheme economic evaluation module (13) is used to evaluate the economics of the scheme and check whether the scheme achieves the minimum or most reasonable power consumption cost. The steps for evaluating the economics of the scheme include: Calculate the operating cost of each pumping station based on its power consumption and electricity price; sum the operating costs of each pumping station to obtain the total operating cost; compare the total operating costs under different schemes and select the scheme with the minimum or most reasonable cost. The multi-stage pump economic dispatch scheme formulation module (14) is used to formulate multi-stage pump economic dispatch schemes and output them to the heating network dispatchers.

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