Closed water system added with standby water source

Abstract

The invention provides a closed water system added with a standby water source, and relates to the technical field of thermal power generation, the closed water system comprises a closed water tank, an overflow pipe is arranged on the closed water tank, a water outlet of the closed water tank is connected with a water conveying pipeline, the water outlet end of the water conveying pipeline is communicated with a water using element, and the water outlet end of the water using element is communicated with a water return pipeline; the water outlet end of the water return pipeline is communicated with a water inlet of the closed water tank, a closed pump is arranged on the water conveying pipeline, the water conveying pipeline is further communicated with a standby pipeline, the standby pipeline is arranged on the water outlet side of the closed pump, a pressure pump is arranged on the standby pipeline, and the water inlet end of the standby pipeline is communicated with the desalted water mother pipe. When the closed pump breaks down and cannot supply water to the water using element, the standby pipeline is connected to supply water to the water conveying pipeline, normal operation of the closed water system is guaranteed, meanwhile, through connection of the standby pipeline, automatic water supplementing of the water conveying pipeline is achieved, stability of the circulating water amount in the closed water system is guaranteed, and the service life of the closed water system is prolonged. And the automatic adjustment of the circulating water quantity is realized.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power generation, and in particular to a closed water system for increasing a backup water source. Background Art

[0002] During the operation of a thermal power plant, a closed water system provides cooling water for turbine and boiler auxiliary machines. The air dehumidification of the boiler air compressor is also carried out through a closed water system. If there is a leak in the exchange device, air will enter the closed water system, causing cavitation in the closed pump, and thus failing to provide cooling for the various auxiliary machines. If the cause cannot be quickly identified, the gas cannot be effectively removed by the exhaust device alone. Summary of the invention

[0003] The present invention provides a closed water system with an additional standby water source, which is used to solve the defect in the prior art that after air enters the cooling water system, the closed water pump will be cavitated, thereby failing to provide cooling for various auxiliary machines.

[0004] On the one hand, the present invention provides a closed water system with an additional backup water source, comprising: a closed water tank, an overflow pipe is arranged on the closed water tank, the water outlet of the closed water tank is connected to a water supply pipeline, the water outlet end of the water supply pipeline is connected to a water-using element, the water outlet end of the water-using element is connected to a return water pipeline, the water outlet end of the return water pipeline is connected to a water inlet of the closed water tank, a closed pump is arranged on the water supply pipeline, the water supply pipeline is also connected to a backup pipeline, the backup pipeline is arranged on the water outlet side of the closed pump, a booster pump is arranged on the backup pipeline, and the water inlet end of the backup pipeline is connected to a desalted jellyfish pipe.

[0005] Preferably, a control system is also included, and the control system includes:

[0006] Parameter monitoring module, used to monitor the operating parameters of the closed water system and adjust the output flow of the closed pump;

[0007] A water source control module is used to control the output status of the standby pipeline;

[0008] The fault alarm module is used to alarm after a fault occurs in the closed water system.

[0009] Preferably, the operating parameters of the closed water system include: water flow temperature, water flow rate, water pressure, liquid level height inside the closed water tank and water quality, and the parameter monitoring module includes:

[0010] A temperature monitoring unit is used to monitor the water flow temperature inside the water pipeline;

[0011] A flow monitoring unit, used to monitor the water flow inside the water pipeline;

[0012] A pressure monitoring unit, used to monitor the water pressure inside the water pipeline;

[0013] A liquid level monitoring unit, used to monitor the liquid level inside the closed water tank;

[0014] A water quality monitoring unit, used to monitor the water quality of the water flow inside the water pipeline;

[0015] The automatic regulating unit regulates the output flow of the closed pump when the water flow rate or the water pressure inside the water pipeline is higher than the corresponding maximum prescribed allowable value.

[0016] Preferably, the water source control module includes:

[0017] An operation evaluation unit, used to evaluate the operation status of the water pipeline;

[0018] A state determination unit, used to determine the output state of the standby pipeline;

[0019] The water source control unit is used to control the working state of the booster pump.

[0020] Preferably, the operating state of the water pipeline includes being polluted and being unpolluted, and the operation evaluation unit includes:

[0021] A first calculation subunit, used for calculating a first operation evaluation value;

[0022] Wherein, S1 is the first operation evaluation value; δ, ε, μ are weight coefficients of the pH value of water, dissolved oxygen content in water and turbidity of water respectively; L is the actual pH value of water in the water pipeline; L0 is the optimal ideal value of the preset pH value; L M0 is the maximum allowable deviation between the pH value and the optimal ideal pH value; R M is the maximum allowable value of dissolved oxygen content in the water in the water pipeline; R is the actual dissolved oxygen content in the water in the water pipeline; R0 is the optimal ideal value of dissolved oxygen content in the water; Z is the actual turbidity value of the water in the water pipeline; Z0 is the optimal ideal value of turbidity of the water; Z M The maximum permissible turbidity of water in the preset water pipeline;

[0023] The state evaluation subunit, when the first operation evaluation value is greater than a preset first threshold value, the evaluation result is contaminated, otherwise the evaluation result is not contaminated.

[0024] Preferably, the output status of the standby pipeline includes: not outputting water source, outputting supplementary water source to the water delivery pipeline, and serving as the only water source for the water delivery pipeline, and the status determination unit includes:

[0025] The operating status acquisition subunit is used to obtain the operating status of the water pipeline

[0026] A second calculation subunit, used for calculating a second operation evaluation value;

[0027] Wherein, S2 is the second operation evaluation value; α, β, and γ are weight coefficients of the flow rate in the water pipeline, the water pressure in the water pipeline, and the water flow temperature in the water pipeline, respectively; Q s is the actual flow rate in the water pipeline; Q x is the flow demand value of the water pipeline; P s is the actual water pressure in the water supply management; P x T is the standard value of water pressure in the water pipeline; s is the actual water flow temperature in the water delivery management; T x is the specified standard value of water pressure in the water pipeline; || is the absolute value symbol;

[0028] The state determination subunit determines that when the operating state of the water supply pipeline is contaminated, the output state of the backup pipeline is determined to be the only water source for the water supply pipeline; otherwise, further judgment is made based on the second operating evaluation value. When the second operating evaluation value is greater than a preset second threshold value, the output state of the backup pipeline is determined to be a supplementary water source output for the water supply pipeline; otherwise, the output state of the backup pipeline is determined to be no water output.

[0029] Preferably, the working state of the booster pump includes not working and working at a specified output flow rate, and the water source control unit includes:

[0030] A state calling subunit is used to call the output state of the standby pipeline;

[0031] The first flow output subunit, when the output state of the standby pipeline is no water output, the working state of the booster pump is not working, when the output state of the standby pipeline is the only water source for the water delivery pipeline, the working state of the booster pump is to work with the flow demand value of the water delivery pipeline as the output flow;

[0032] A flow calculation unit, used for calculating a target working flow value of the booster pump when the output state of the standby pipeline is to output a supplementary water source to the water delivery pipeline;

[0033] The second flow output unit is used for when the output state of the standby pipeline is to output a supplementary water source to the water delivery pipeline, the working state of the booster pump is to work with the target working flow value of the booster pump 8) as the output flow.

[0034] Preferably, the flow calculation unit calculates the target working flow value of the booster pump based on the following steps;

[0035] Step 1: Based on the water pressure requirement of the water delivery pipeline (3), a first flow rate candidate value and a second flow rate candidate value are calculated;

[0036] Among them, Q m11 is the first flow alternative value; Q m12 is the second flow rate alternative value; Q s is the actual flow rate in the water pipeline; P s is the actual water pressure in the water supply management; P x is the specified standard value of water pressure in the water pipeline; ρ is the density of water; A is the pipe diameter of the water pipeline;

[0037] Step 2: Based on the output flow rate allowable range of the booster pump, one of the first flow rate candidate value and the second flow rate candidate value that is within the output flow rate allowable range of the booster pump is selected as the water pressure calculation candidate value;

[0038] Step 3: Calculate the alternative value of flow calculation;

[0039] Q m2 =Q x -Q s ; Among them, Q m2 Calculate alternative values ​​for flow rate; Q s is the actual flow rate in the water pipeline; Q x is the flow demand value of the water pipeline;

[0040] Step 4: Obtaining a target working flow value of the booster pump based on the water pressure calculation candidate value and the flow calculation candidate value;

[0041] Q m =max(Q m1 , Q m2 ), where Q m is the target working flow value of the booster pump; Q m1 Calculate the alternative value for water pressure; Q m2 Calculates alternative values ​​for flow.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] When a closed pump fails and cannot supply water to water-using components, water is supplied to the water supply pipeline by connecting to the backup pipeline, thereby ensuring the normal operation of the closed water system. At the same time, automatic water replenishment of the water supply pipeline is achieved through the access of the backup pipeline. When the amount of water stored in the closed water tank is too much, the excess water can flow out through the overflow pipe of the closed water tank, thereby ensuring the stability of the circulating water volume inside the closed water system and realizing automatic adjustment of the circulating water volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 It is a structural schematic diagram of the present invention.

[0046] Reference numerals:

[0047] 1. Closed water tank; 2. Overflow pipe; 3. Water supply pipeline; 4. Water-using elements; 5. Return pipeline; 6. Closed pump; 7. Spare pipeline; 8. Pressure pump; 9. Desalination jellyfish pipe. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0049] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0050] Example 1

[0051] An embodiment of the present invention provides a closed water system for adding a backup water source, comprising: a closed water tank 1, an overflow pipe 2 is arranged on the closed water tank 1, the water outlet of the closed water tank 1 is connected to a water supply pipeline 3, the water outlet end of the water supply pipeline 3 is connected to a water use element 4, the water outlet end of the water use element 4 is connected to a return water pipeline 5, the water outlet end of the return water pipeline 5 is connected to the water inlet of the closed water tank 1, a closed pump 6 is arranged on the water supply pipeline 3, the water supply pipeline 3 is also connected to a backup pipeline 7, the backup pipeline 7 is arranged on the water outlet side of the closed pump 6, a booster pump 8 is arranged on the backup pipeline 7, and the water inlet end of the backup pipeline 7 is connected to a desalted jellyfish pipe 9.

[0052] In this embodiment, the water-using element 4 includes a steam turbine auxiliary machine, a boiler auxiliary machine and a boiler air compressor.

[0053] The beneficial effects of the above technical solution are:

[0054] When the closed pump 6 fails and cannot supply water to the water-using element 4, the water supply pipeline 3 is supplied with water by connecting to the backup pipeline 7, thereby ensuring the normal operation of the closed water system. At the same time, through the connection of the backup pipeline 7, automatic water replenishment of the water supply pipeline 3 is achieved. When the amount of water stored in the closed water tank 1 is too much, the excess water can flow out through the overflow pipe 2 of the closed water tank 1, thereby ensuring the stability of the circulating water volume inside the closed water system and realizing automatic adjustment of the circulating water volume.

[0055] Example 2

[0056] On the basis of embodiment 1, a control system is also included, and the control system includes:

[0057] A parameter monitoring module, used to monitor the operating parameters of the closed water system and adjust the output flow of the closed pump 6;

[0058] A water source control module, used to control the output state of the standby pipeline 7;

[0059] The fault alarm module is used to alarm after a closed water system fails.

[0060] Preferably, the operating parameters of the closed water system include: water flow temperature, water flow rate, water pressure, liquid level height inside the closed water tank 1 and water quality, and the parameter monitoring module includes:

[0061] A temperature monitoring unit, used to monitor the water flow temperature inside the water delivery pipeline 3;

[0062] A flow monitoring unit, used to monitor the water flow inside the water delivery pipeline 3;

[0063] A pressure monitoring unit, used to monitor the water pressure inside the water delivery pipeline 3;

[0064] A liquid level monitoring unit, used to monitor the liquid level inside the closed water tank 1;

[0065] A water quality monitoring unit, used to monitor the water quality of the water flow inside the water delivery pipeline 3;

[0066] The automatic regulating unit regulates the output flow of the closed pump 6 when the water flow rate or the water pressure in the water delivery pipeline 3 is higher than the corresponding maximum prescribed allowable value.

[0067] In this embodiment, the items of water quality monitoring include: pH value, solution oxygen content, and turbidity.

[0068] The beneficial effects of the above technical solution are:

[0069] By monitoring the operating parameters of the closed water system and adjusting the output flow of the closed pump 6 according to the detection data, it is ensured that the operating parameters of the closed water system are within the corresponding allowable range during normal operation, thereby achieving self-regulation of the closed water system.

[0070] Example 3

[0071] Based on Example 2, the water source control module includes:

[0072] An operation evaluation unit, used to evaluate the operation status of the water delivery pipeline 3;

[0073] A state determination unit, used to determine the output state of the standby pipeline 7;

[0074] The water source control unit is used to control the working state of the booster pump 8.

[0075] Preferably, the operating state of the water delivery pipeline 3 includes being polluted and being unpolluted, and the operation evaluation unit includes:

[0076] A first calculation subunit, used for calculating a first operation evaluation value;

[0077] Wherein, S1 is the first operation evaluation value; δ, ε, μ are weight coefficients (values ​​greater than 0 and less than 1) of the pH value of water, the dissolved oxygen content in water, and the turbidity of water, respectively; L is the actual pH value of the water in the water pipeline 3; L0 is the optimal ideal value of the preset pH value; L M0 is the maximum allowable deviation between the pH value and the optimal ideal pH value; R M is the maximum allowable value of dissolved oxygen content in the water in the water pipeline 3; R is the actual dissolved oxygen content in the water in the water pipeline 3; R0 is the optimal ideal value of dissolved oxygen content in the water; Z is the actual turbidity value of the water in the water pipeline 3; Z0 is the optimal ideal value of turbidity of the water; Z M is the maximum permissible turbidity of water in the preset water delivery pipeline 3;

[0078] The state evaluation subunit, when the first operation evaluation value is greater than a preset first threshold value, the evaluation result is contaminated, otherwise the evaluation result is not contaminated.

[0079] Preferably, the output states of the standby pipeline 7 include: no water output, supplementary water output to the water delivery pipeline 3, and serving as the only water source for the water delivery pipeline 3. The state determination unit includes:

[0080] The operating status acquisition subunit is used to acquire the operating status of the water delivery pipeline 3.

[0081] A second calculation subunit, used for calculating a second operation evaluation value;

[0082] Wherein, S2 is the second operation evaluation value; α, β, γ are weight coefficients (values ​​greater than 0 and less than 1) of the flow rate in the water pipeline 3, the water pressure in the water pipeline 3, and the water flow temperature in the water pipeline 3, respectively; Q s is the actual flow rate in the water pipeline 3; Q x is the flow demand value of water pipeline 3; P s is the actual water pressure in the water supply management; P x is the specified standard value of water pressure in water pipeline 3; T s is the actual water flow temperature in the water delivery management; T x is the specified standard value of water pressure in water pipeline 3; || is the absolute value symbol;

[0083] The state determination subunit determines that when the operating state of the water supply pipeline 3 is contaminated, the output state of the backup pipeline 7 is determined to be the only water source for the water supply pipeline 3; otherwise, further judgment is made based on the second operating evaluation value. When the second operating evaluation value is greater than the preset second threshold value, the output state of the backup pipeline 7 is determined to be a supplementary water source output for the water supply pipeline 3; otherwise, the output state of the backup pipeline 7 is determined to be no water output.

[0084] Preferably, the working state of the booster pump 8 includes not working and working at a specified output flow rate, and the water source control unit includes:

[0085] The state calling subunit is used to call the output state of the standby pipeline 7;

[0086] The first flow output subunit, when the output state of the standby pipeline 7 is no water output, the working state of the booster pump 8 is not working, and when the output state of the standby pipeline 7 is the only water source of the water delivery pipeline 3, the working state of the booster pump 8 is to work with the flow demand value of the water delivery pipeline 3 as the output flow;

[0087] A flow calculation unit, used for calculating a target working flow value of the booster pump 8 when the output state of the standby pipeline 7 is to output a supplementary water source to the water delivery pipeline 3;

[0088] The second flow output unit is used for when the output state of the backup pipeline 7 is to output a supplementary water source to the water delivery pipeline 3, the working state of the booster pump 8 is to work with the target working flow value of the booster pump 8 as the output flow.

[0089] Preferably, the flow calculation unit calculates the target working flow value of the booster pump 8 based on the following steps;

[0090] Step 1: Based on the water pressure requirement of the water delivery pipeline 3, a first flow rate candidate value and a second flow rate candidate value are calculated;

[0091] Among them, Q m11 is the first flow alternative value; Q m12 is the second flow rate alternative value; Q s is the actual flow rate in the water delivery pipeline 3; P s is the actual water pressure in the water supply management; P x is the specified standard value of the water pressure of the water delivery pipeline 3; ρ is the density of water; A is the pipe diameter of the water delivery pipeline 3;

[0092] Step 2: Based on the output flow rate allowable range of the booster pump 8, one of the first flow rate candidate value and the second flow rate candidate value that is within the output flow rate allowable range of the booster pump 8 is selected as the water pressure calculation candidate value;

[0093] Step 3: Calculate the alternative value of flow calculation;

[0094] Q m2 =Q x -Q s ; Among them, Q m2 Calculate alternative values ​​for flow rate; Q s is the actual flow rate in the water pipeline 3; Q x is the flow demand value of water pipeline 3;

[0095] Step 4: Obtaining a target working flow value of the booster pump 8 based on the water pressure calculation candidate value and the flow calculation candidate value;

[0096] Q m =max(Q m1 , Q m2 ), where Q m Q is the target working flow value of the booster pump 8; m1 Calculate the alternative value for water pressure; Q m2In this embodiment, the flow demand value of the water delivery pipeline 3 is the sum of the flow demand values ​​of all water-using components 4 .

[0097] The beneficial effects of the above technical solution are:

[0098] By regularly evaluating the operating status of the water delivery pipeline 3 , it is determined whether the backup pipeline 7 needs to be activated, thereby ensuring that the backup pipeline 7 is activated in time after an abnormality occurs in the water delivery pipeline 3 .

[0099] When evaluating the operating status of the water pipeline 3, by calculating the first operating evaluation value, it is determined whether the inside of the water pipeline 3 is contaminated, so as to determine whether it is necessary to shut down the closed pump 6 and use the backup pipeline 7 to supply water to the water pipeline 3, so as to ensure that the water quality of the water flowing inside the water pipeline 3 is qualified, and to avoid the water with unqualified water quality circulating in the water pipeline 3 for a long time, causing the water pipeline 3 to be blocked.

[0100] When it is determined that the operating status of the water pipeline 3 is uncontaminated, the second operating evaluation value is calculated based on the actual flow, actual water pressure and actual temperature inside the water pipeline 3, so as to determine whether it is necessary to supplement the water source input to the water pipeline 3 by starting the backup pipeline 7, thereby ensuring that the operating parameters of the water pipeline 3 are maintained within the allowable range.

[0101] When the output state of the backup pipeline 7 is to output a supplementary water source to the water supply pipeline 3, the target working flow values ​​of the two booster pumps 8 are first obtained based on the flow and water pressure required to be supplemented by the water supply pipeline 3. By selecting the target working flow value with a larger value as the actual target working flow value, it is ensured that the flow and water pressure inside the water supply pipeline 3 are within the corresponding allowable range at the same time, thereby ensuring the normal operation of the water supply pipeline 3.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A closed water system with an additional backup water source, characterized in that: include: A closed water tank (1) is provided with an overflow pipe (2), a water outlet of the closed water tank (1) is connected to a water delivery pipeline (3), a water outlet end of the water delivery pipeline (3) is connected to a water-using element (4), a water outlet end of the water-using element (4) is connected to a return water pipeline (5), a water outlet end of the return water pipeline (5) is connected to a water inlet of the closed water tank (1), a closed pump (6) is provided on the water delivery pipeline (3), a spare pipeline (7) is also connected to the water delivery pipeline (3), the spare pipeline (7) is provided on the water outlet side of the closed pump (6), a booster pump (8) is provided on the spare pipeline (7), and a water inlet end of the spare pipeline (7) is connected to a desalted jellyfish pipe (9).

2. A closed water system for increasing a backup water source according to claim 1, characterized in that: It also includes a control system, which includes: A parameter monitoring module, used to monitor the operating parameters of the closed water system and adjust the output flow of the closed pump (6); A water source control module, used to control the output state of the standby pipeline (7); The fault alarm module is used to alarm after a fault occurs in the closed water system.

3. A closed water system for increasing a backup water source according to claim 2, characterized in that: The operating parameters of the closed water system include: water flow temperature, water flow rate, water pressure, liquid level height inside the closed water tank (1) and water flow quality. The parameter monitoring module includes: A temperature monitoring unit, used to monitor the water flow temperature inside the water delivery pipeline (3); A flow monitoring unit, used to monitor the water flow inside the water delivery pipeline (3); A pressure monitoring unit, used to monitor the water pressure inside the water delivery pipeline (3); A liquid level monitoring unit, used to monitor the liquid level inside the closed water tank (1); A water quality monitoring unit, used to monitor the water quality of the water flow inside the water delivery pipeline (3); The automatic regulating unit regulates the output flow of the closed pump (6) when the water flow rate or the water pressure in the water delivery pipeline (3) is higher than the corresponding maximum permitted value.

4. A closed water system for increasing a backup water source according to claim 3, characterized in that: The water source control module includes: An operation evaluation unit, used to evaluate the operation status of the water delivery pipeline (3); A state determination unit, used to determine the output state of the standby pipeline (7); The water source control unit is used to control the working state of the booster pump (8).

5. A closed water system for adding a backup water source according to claim 4, characterized in that: The operation status of the water pipeline (3) includes being polluted and being unpolluted, and the operation evaluation unit includes: A first calculation subunit, used for calculating a first operation evaluation value; Wherein, S1 is the first operation evaluation value; δ, ε, μ are weight coefficients of the pH value of water, the dissolved oxygen content in water and the turbidity of water respectively; L is the actual pH value of water in the water pipeline (3); L0 is the optimal ideal value of the preset pH value; L M0 is the maximum allowable deviation between the pH value and the optimal ideal pH value; R M is the maximum permissible value of the dissolved oxygen content in the water in the water pipeline (3); R is the actual dissolved oxygen content in the water in the water pipeline (3); R0 is the optimal ideal value of the dissolved oxygen content in the water; Z is the actual turbidity value of the water in the water pipeline (3); Z0 is the optimal ideal value of the turbidity of the water; Z M is the maximum permissible turbidity of water in the preset water delivery pipeline (3); The state evaluation subunit, when the first operation evaluation value is greater than a preset first threshold value, the evaluation result is contaminated, otherwise the evaluation result is not contaminated.

6. A closed water system for adding a backup water source according to claim 5, characterized in that: The output states of the standby pipeline (7) include: not outputting water, outputting supplementary water to the water delivery pipeline (3), and serving as the only water source for the water delivery pipeline (3). The state determination unit includes: The operating status acquisition subunit is used to acquire the operating status of the water delivery pipeline (3) A second calculation subunit, used for calculating a second operation evaluation value; Wherein, S2 is the second operation evaluation value; α, β, and γ are weight coefficients of the flow rate in the water pipeline (3), the water pressure in the water pipeline (3), and the water flow temperature in the water pipeline (3), respectively; Q s is the actual flow rate in the water pipeline (3); Q x is the flow demand value of the water pipeline (3); P s is the actual water pressure in the water supply management; P x is the specified standard value of the water pressure in the water pipeline (3); T s is the actual water flow temperature in the water delivery management; T x is the specified standard value of the water pressure in the water pipeline (3); || is the absolute value symbol; The state determination subunit determines that when the operating state of the water supply pipeline (3) is contaminated, the output state of the backup pipeline (7) is determined to be the sole water source for the water supply pipeline (3); otherwise, further judgment is made based on the second operating evaluation value; when the second operating evaluation value is greater than a preset second threshold value, the output state of the backup pipeline (7) is determined to be a supplementary water source output for the water supply pipeline (3); otherwise, the output state of the backup pipeline (7) is determined to be no water source output.

7. A closed water system for adding a backup water source according to claim 6, characterized in that: The working state of the booster pump (8) includes not working and working at a specified output flow rate. The water source control unit includes: A state calling subunit, used for calling the output state of the standby pipeline (7); The first flow output subunit, when the output state of the standby pipeline (7) is no water output, the working state of the booster pump (8) is not working, and when the output state of the standby pipeline (7) is to serve as the only water source for the water delivery pipeline (3), the working state of the booster pump (8) is to work with the flow demand value of the water delivery pipeline (3) as the output flow; A flow calculation unit, used for calculating a target working flow value of the booster pump (8) when the output state of the standby pipeline (7) is to output a supplementary water source to the water delivery pipeline (3); The second flow output unit is used for, when the output state of the standby pipeline (7) is to output a supplementary water source to the water delivery pipeline (3), the working state of the booster pump (8) is to work with the target working flow value of the booster pump (8) as the output flow.

8. A closed water system for adding a backup water source according to claim 7, characterized in that: The flow calculation unit calculates the target working flow value of the booster pump (8) based on the following steps; Step 1: Based on the water pressure requirement of the water delivery pipeline (3), a first flow rate candidate value and a second flow rate candidate value are calculated; Among them, Q m11 is the first flow alternative value; Q m12 is the second flow rate alternative value; Q s is the actual flow rate in the water pipeline (3); P s is the actual water pressure in the water supply management; P x is the specified standard value of the water pressure of the water delivery pipeline (3); ρ is the density of water; A is the pipe diameter of the water delivery pipeline (3); Step 2: Based on the allowable range of the output flow rate of the booster pump (8), one of the first flow rate candidate value and the second flow rate candidate value that is within the allowable range of the output flow rate of the booster pump (8) is selected as the water pressure calculation candidate value; Step 3: Calculate the alternative value of flow calculation; Q m2 =Q x -Q s ; Among them, Q m2 Calculate alternative values ​​for flow rate; Q s is the actual flow rate in the water pipeline (3); Q x is the flow demand value of the water delivery pipeline (3); Step 4: obtaining a target working flow value of the booster pump (8) based on the water pressure calculation candidate value and the flow calculation candidate value; Q m =max(Q m1 , Q m2 ), where Q m is the target working flow value of the booster pump (8); Q m1 Calculate the alternative value for water pressure; Q m2 Calculates alternative values ​​for flow.

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