Energy conservation and carbon reduction evaluation method and system based on urban rainwater collection system

Abstract

The invention provides an energy conservation and carbon reduction evaluation method and system based on an urban rainwater collection system, and relates to the technical field of energy conservation and carbon reduction evaluation. The method comprises the following steps: processing a rainfall record of a city, and segmenting the rainfall record into discrete rainfall events; according to the method, a water supply and demand balance reliability model of a rainwater collection system of a single building is established through the water utilization rate of a drought period and the water utilization rate of a rainfall period in the single building, and the water supply and demand balance reliability of the rainwater collection system is solved by using the water supply and demand balance reliability model. When the water supply and demand balance reliability of the rainwater collection system reaches a set threshold value, the optimal rainwater collection capacity meeting the water supply and demand balance reliability of the rainwater collection system is calculated, and based on the optimal rainwater collection capacity, the amount of water which can be actually used for replacing traditional water supply through the rainwater collection system is evaluated; the power consumption and the carbon emission reduction which are reduced by urban scale annual water supply reduction are deduced, the calculation complexity is reduced, and the application universality of the method is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and carbon reduction assessment, and more specifically, to an energy conservation and carbon reduction assessment method and system based on an urban rainwater collection system. Background Art

[0002] Guided by the "dual carbon" goals, energy conservation and emission reduction in urban water supply systems have become a key focus of green infrastructure transformation and upgrading. Rainwater harvesting (RWH), as a key alternative to traditional water sources in urban water supply systems, has played a significant role in alleviating urban water resource shortages, reducing drainage loads, and improving the ecological environment in recent years. Especially when deployed on a large scale, RWH systems can, to a certain extent, replace urban tap water supply, thereby achieving a synergistic effect of energy conservation and carbon emission reduction.

[0003] In this context, rationally quantifying the carbon emissions reductions and energy savings of rainwater harvesting systems is crucial. Existing technologies quantify and compare the carbon emissions of urban rainwater harvesting systems with those of traditional drainage systems by defining a carbon emission accounting boundary for rainwater harvesting systems. This carbon emission accounting boundary encompasses both temporal and spatial dimensions. The temporal boundary considers the entire lifecycle of the rainwater harvesting system, calculating carbon emissions from the construction, operation, and demolition and renovation phases. The spatial boundary, on the other hand, accounts for carbon emissions from rainfall throughout its entire process, from runoff formation, infiltration and collection, storage and control, to reuse. Existing technologies utilize a full lifecycle assessment approach to calculate carbon emissions for rainwater harvesting systems, avoiding the one-sided focus on carbon reduction during the operational phase. However, these technologies decompose the entire lifecycle of rainwater harvesting systems into multiple cycles, including material production and transportation, construction, and system maintenance. This results in high computational complexity and reliance on a large amount of existing local rainfall data and rainwater harvesting system utilization rates. This ignores key factors such as the randomness of rainfall and its uneven geographical distribution, making it difficult to generalize to other regions and limiting its universal applicability. Summary of the Invention

[0004] To address the problems of high computational complexity and low universality in current energy-saving and carbon-reduction assessment methods for urban rainwater collection systems, the present invention proposes an energy-saving and carbon-reduction assessment method and system based on urban rainwater collection systems. The method evaluates the amount of water that can actually be used to replace traditional water supply through the rainwater collection system, and derives the reduced power consumption and carbon emissions caused by the reduction in annual water supply at the urban scale, thereby reducing the computational complexity and improving the universality of the method's application.

[0005] In order to achieve the above technical effects, the technical solutions of the present invention are as follows:

[0006] In the first aspect, this application proposes an energy conservation and carbon reduction assessment method based on an urban rainwater collection system, comprising the following steps:

[0007] Obtain rainfall records for a city within a T-time period and divide the rainfall records into discrete rainfall events;

[0008] The average effective rainwater collection area and runoff coefficient of the top of a single building in the city are obtained, and combined with the rainfall depth of a single rainfall event, the effective rainfall depth of a single building in a single rainfall event is calculated;

[0009] Obtain the water consumption rate during the dry period and the water consumption rate during the rainy period within a single building, establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and use the water supply and demand balance reliability model to solve the water supply and demand balance reliability of the rainwater collection system;

[0010] When the reliability of the water supply and demand balance of the rainwater collection system reaches the set threshold, the optimal rainwater collection capacity that meets the reliability of the water supply and demand balance of the rainwater collection system is calculated. Based on the optimal rainwater collection capacity, the reduced domestic water supply of a single building is calculated;

[0011] Count the buildings in the city that use rainwater collection systems, calculate the reduced electricity consumption due to the reduction in domestic water supply, and obtain the reduced carbon emissions due to the reduced electricity consumption.

[0012] In this technical solution, the city's rainfall records are first processed and divided into discrete rainfall events; the water consumption rate during the dry period and the water consumption rate during the rainy period in a single building are used to establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and the water supply and demand balance reliability model is used to solve the water supply and demand balance reliability of the rainwater collection system. When the water supply and demand balance reliability of the rainwater collection system reaches a set threshold, the optimal rainwater collection capacity that meets the water supply and demand balance reliability of the rainwater collection system is calculated. Based on the optimal rainwater collection capacity, the amount of water that can actually be used to replace traditional water supply through the rainwater collection system is evaluated, and the reduced electricity consumption and carbon emissions caused by the reduction in annual water supply at the urban scale are derived, which reduces the complexity of the calculation and improves the universality of the method application.

[0013] Preferably, the process of segmenting rainfall records into discrete rainfall events is:

[0014] Rainfall records whose rainfall depth did not reach the low rainfall threshold were eliminated;

[0015] Determine whether the rainfall depth of a rainfall event is less than the rainfall depth threshold. If so, merge the rainfall event into the rainfall event with the closest rainfall time and a rainfall depth greater than or equal to the rainfall depth threshold. If the rainfall depth is greater than or equal to the rainfall depth threshold, treat it as an independent rainfall event and segment it.

[0016] Determine whether the time interval between two rainfall events is less than the set minimum time interval. If so, merge the two consecutive rainfall events into one independent rainfall event. If the time interval between two rainfall events is greater than or equal to the set minimum time interval, separate the two rainfall records into two independent rainfall events.

[0017] Preferably, after dividing the rainfall record into discrete rainfall events, the method further comprises designing a probability density function obeyed by random variables of dry period duration, rainfall duration and rainfall depth of a single rainfall event in the rainfall record and calculating parameters of the probability density function;

[0018] The method used to calculate the parameters of the probability density function is the maximum likelihood estimation method, and the process is:

[0019] Calculate the dry period duration t of all independent rainfall events in the time period T n , rainfall duration t r and rainfall depth d r The mean of

[0020] Take the duration of drought period t n , rainfall duration t r and rainfall depth d r The inverse of the mean of the drought period is obtained as t n The random variable T n The probability density function of the rate parameter ψ, rainfall duration t r The random variable T r The probability density function of the rate parameter ξ, rainfall depth d r The random variable D r The rate parameter λ of the probability density function;

[0021] The probability density function P obeyed by the random variables of the three rainfall characteristic indicators is designed r , the expressions are:

[0022]

[0023] Among them, P r (T n =t n ) is the duration of the drought period t n The random variable T n The probability density function, P r (T r =t r ) is the rainfall duration t r The random variable T r The probability density function, P r (D r=d r ) is the rainfall depth d r The random variable D r The probability density function of .

[0024] Preferably, the vertical projection area of the building top from which rainwater can be collected is taken as the average effective rainwater collection area α on the top of a single building, and the proportion of rainfall converted into runoff is taken as the runoff coefficient Calculate the effective rainfall depth D of a single building in a single rainfall event eff , the calculation expression is:

[0025]

[0026] Among them, D r is the rainfall depth d r The random variable d f The depth of the first flush of rainfall.

[0027] Preferably, the average hourly water consumption during non-rainfall periods is used as the water consumption rate d1 of a single building during the dry period, the average hourly water consumption during rainfall periods is used as the water consumption rate d2 of a single building during the rainfall period, and the average proportion of time during which the rainwater collected in the rainwater collection system of a single building meets the total water demand in all rainwater collection cycles is used as the water supply and demand balance reliability r of the rainwater collection system of a single building. A water supply and demand balance reliability model of the rainwater collection system of a single building is established, and the expression is:

[0028]

[0029] Where v represents the rainwater storage capacity of the rainwater collection system of a single building, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

[0030] Preferably, the calculation satisfies the optimal rainwater collection capacity v that satisfies the reliability of the water supply and demand balance of the rainwater collection system. r , the expression is:

[0031]

[0032] Where α represents the average effective rainwater collection area on the top of a single building, represents the runoff coefficient, d1 represents the water consumption rate in a single building during the dry period, d2 represents the water consumption rate in a single building during the rainy period, r represents the reliability of the water supply and demand balance of the rainwater collection system of a single building, and ψ represents the duration of the dry period t n The random variable T n The rate parameter of the probability density function, ξ represents the duration of rainfall t rThe random variable T n The rate parameter of the probability density function, λ represents the rainfall depth d r The random variable D r The rate parameter of the probability density function, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

[0033] Preferably, the reduced domestic water supply V for a single building is calculated based on the optimal rainwater collection capacity. save , the expression is:

[0034] V save =min(v r +d2×t r ,D eff )

[0035] Among them, t r is the duration of rainfall, d2 is the water consumption rate during the rainfall period, and when it is in the rainfall period, the rainwater collection system directly collects rainwater to meet the water demand during the rainfall period.

[0036] Preferably, the statistics of buildings using rainwater collection units in the city are used to calculate the power consumption W reduced due to the reduction in domestic water supply. save , the expression is:

[0037]

[0038] Where N is the total number of buildings using rainwater harvesting units in the city, I is the total number of independent rainfall events, and EH is the average electricity consumption per cubic meter of water provided by the water supply system.

[0039] Preferably, the calculation of the carbon emissions reduced due to the reduction in power consumption is performed save , the expression is:

[0040]

[0041] in, It is the recommended value of carbon emission factor, which is used to measure the carbon dioxide emitted for each kilowatt-hour of electricity. It is the global warming potential coefficient of carbon dioxide, which is used to convert the emissions of various greenhouse gases into carbon dioxide emissions.

[0042] Secondly, this application also proposes an energy-saving and carbon-reduction assessment system based on an urban rainwater collection system, the system comprising:

[0043] The rainfall event segmentation module is used to obtain rainfall records within a certain city within a period of T and segment the rainfall records into discrete rainfall events;

[0044] The effective rainfall depth calculation module is used to obtain the average effective rainwater collection area and runoff coefficient on the top of a single building in the city, and combine it with the rainfall depth of a single rainfall event to calculate the effective rainfall depth of a single building in a single rainfall event;

[0045] The water supply and demand balance reliability calculation module is used to obtain the water consumption rate during the dry period and the water consumption rate during the rainy period in a single building, establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and use the water supply and demand balance reliability model to solve the water supply and demand balance reliability of the rainwater collection system;

[0046] The water supply calculation module is used to calculate the optimal rainwater collection capacity that meets the water supply and demand balance reliability of the rainwater collection system when the water supply and demand balance reliability of the rainwater collection system reaches a set threshold. Based on the optimal rainwater collection capacity, the reduced domestic water supply of a single building is calculated;

[0047] The electricity consumption and carbon emissions accounting module is used to count the buildings in the city that use rainwater collection systems, calculate the reduced electricity consumption due to the reduction in domestic water supply, and obtain the reduced carbon emissions due to the reduced electricity consumption.

[0048] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0049] The present invention proposes an energy-saving and carbon-reduction assessment method and system based on an urban rainwater collection system. First, the city's rainfall records are processed and divided into discrete rainfall events. Then, a water supply and demand balance reliability model of the rainwater collection system of a single building is established through the water consumption rate during the dry period and the water consumption rate during the rainy period in a single building. The water supply and demand balance reliability model is used to solve the water supply and demand balance reliability of the rainwater collection system. When the water supply and demand balance reliability of the rainwater collection system reaches a set threshold, the optimal rainwater collection capacity that meets the water supply and demand balance reliability of the rainwater collection system is calculated. Based on the optimal rainwater collection capacity, the amount of water that can actually be used to replace traditional water supply through the rainwater collection system is evaluated, and the reduced power consumption and carbon emission reduction caused by the reduction in annual water supply at the urban scale are derived, thereby reducing the complexity of the calculation and improving the universality of the method application. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram showing a flow chart of an energy-saving and carbon-reduction assessment method based on an urban rainwater collection system proposed in Example 1 of the present invention;

[0051] Figure 2 A distribution diagram showing the optimal rainwater collection capacity of rainwater collection systems for buildings in Guangzhou and the optimal rainwater collection capacity of rainwater collection systems for buildings in each district, as proposed in Example 2 of the present invention;

[0052] Figure 3A distribution diagram showing the average reduction in water supply to various buildings in Guangzhou City proposed in Example 2 of the present invention;

[0053] Figure 4 A structural diagram of an energy-saving and carbon-reduction assessment system based on an urban rainwater collection system proposed in Example 3 of the present invention is shown. DETAILED DESCRIPTION

[0054] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0055] In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the actual size;

[0056] It is understandable to those skilled in the art that descriptions of certain well-known contents may be omitted in the drawings.

[0057] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0058] The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent;

[0059] Example 1

[0060] This embodiment proposes an energy conservation and carbon reduction assessment method based on an urban rainwater collection system. The flow chart of this method is shown in Figure 1 , including the following steps:

[0061] Obtain rainfall records for a city over the past three years and divide the rainfall records into discrete rainfall events;

[0062] The average effective rainwater collection area and runoff coefficient of the top of a single building in the city are obtained, and combined with the rainfall depth of a single rainfall event, the effective rainfall depth of a single building in a single rainfall event is calculated;

[0063] Obtain the water consumption rate during the dry period and the water consumption rate during the rainy period within a single building, establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and use the water supply and demand balance reliability model to solve the water supply and demand balance reliability of the rainwater collection system;

[0064] When the reliability of the water supply and demand balance of the rainwater collection system reaches the set threshold, the optimal rainwater collection capacity that meets the reliability of the water supply and demand balance of the rainwater collection system is calculated. Based on the optimal rainwater collection capacity, the reduced domestic water supply of a single building is calculated;

[0065] Count the buildings in the city that use rainwater collection systems, calculate the reduced electricity consumption due to the reduction in domestic water supply, and obtain the reduced carbon emissions due to the reduced electricity consumption.

[0066] In this embodiment, the city's rainfall records are first processed and divided into discrete rainfall events. Then, a water supply and demand balance reliability model for the rainwater collection system of a single building is established based on the water consumption rate during the dry period and the water consumption rate during the rainy period within a single building. The water supply and demand balance reliability model is used to solve the water supply and demand balance reliability of the rainwater collection system. When the water supply and demand balance reliability of the rainwater collection system reaches a set threshold, the optimal rainwater collection capacity that meets the water supply and demand balance reliability of the rainwater collection system is calculated. Based on the optimal rainwater collection capacity, the amount of water that can actually be used to replace traditional water supply through the rainwater collection system is evaluated, and the reduced electricity consumption and carbon emissions caused by the reduction in annual water supply at the city scale are derived, thereby reducing the complexity of the calculation and improving the universality of the method application.

[0067] Example 2

[0068] In this embodiment, the process of segmenting rainfall records into discrete rainfall events is as follows:

[0069] Rainfall records whose rainfall depth did not reach the low rainfall threshold were eliminated;

[0070] Determine whether the rainfall depth of a rainfall event is less than the rainfall depth threshold. If so, merge the rainfall event into the rainfall event with the closest rainfall time and a rainfall depth greater than or equal to the rainfall depth threshold. If the rainfall depth is greater than or equal to the rainfall depth threshold, treat it as an independent rainfall event and segment it.

[0071] Determine whether the time interval between two rainfall events is less than the set minimum time interval. If so, merge the two consecutive rainfall events into one independent rainfall event. If the time interval between two rainfall events is greater than or equal to the set minimum time interval, separate the two rainfall records into two independent rainfall events.

[0072] Specifically, low rainfall threshold = 0.1 mm, rainfall depth threshold = 50 mm, and minimum time interval = 6 hours.

[0073] In this embodiment, after dividing the rainfall record into discrete rainfall events, the method further includes designing a probability density function obeyed by random variables of the dry period duration, rainfall duration, and rainfall depth of a single rainfall event in the rainfall record and calculating parameters of the probability density function;

[0074] The method used to calculate the parameters of the probability density function is the maximum likelihood estimation method, and the process is:

[0075] Calculate the duration of the drought period t for all independent rainfall events within three years n , rainfall duration t r and rainfall depth d r The mean of

[0076] Take the duration of drought period t n , rainfall duration t r and rainfall depth d r The inverse of the mean of the drought period is obtained as t n The random variable T n The probability density function of the rate parameter ψ, rainfall duration t r The random variable T r The probability density function of the rate parameter ξ, rainfall depth d r The random variable D r The rate parameter λ of the probability density function;

[0077] The probability density function P obeyed by the random variables of the three rainfall characteristic indicators is designed r , the expressions are:

[0078]

[0079] Among them, P r (T n =t n ) is the duration of the drought period t n The random variable T n The probability density function, P r (T r =t r ) is the rainfall duration t r The random variable T r The probability density function, P r (D r =d r ) is the rainfall depth d r The random variable D r The probability density function of .

[0080] In this embodiment, the vertical projection area of the building top from which rainwater can be collected is taken as the average effective rainwater collection area α on the top of a single building, and the proportion of rainfall converted into runoff is taken as the runoff coefficient. Calculate the effective rainfall depth D of a single building in a single rainfall event eff , the calculation expression is:

[0081]

[0082] Among them, D r is the rainfall depth d r The random variable d f The depth of the first flush of rainfall.

[0083] In this embodiment, the average hourly water consumption during non-rainfall periods is used as the water consumption rate d1 of a single building during the dry period, the average hourly water consumption during rainfall periods is used as the water consumption rate d2 of a single building during the rainfall period, and the average proportion of time during which the rainwater collected in the rainwater collection system of a single building meets the total water demand during all rainwater collection cycles is used as the water supply and demand balance reliability r of the rainwater collection system of a single building. A water supply and demand balance reliability model of the rainwater collection system of a single building is established, and the expression is:

[0084]

[0085] Where v represents the rainwater storage capacity of the rainwater collection system of a single building, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

[0086] In this embodiment, the calculation satisfies the optimal rainwater collection capacity v that satisfies the reliability of the water supply and demand balance of the rainwater collection system. r , the expression is:

[0087]

[0088] Where α represents the average effective rainwater collection area on the top of a single building, represents the runoff coefficient, d1 represents the water consumption rate in a single building during the dry period, d2 represents the water consumption rate in a single building during the rainy period, r represents the reliability of the water supply and demand balance of the rainwater collection system of a single building, and ψ represents the duration of the dry period t n The random variable T n The rate parameter of the probability density function, ξ represents the duration of rainfall t r The random variable T n The rate parameter of the probability density function, λ represents the rainfall depth d r The random variable D r The rate parameter of the probability density function, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

[0089] Specifically, taking Guangzhou as an example, the optimal rainwater collection capacity of the rainwater collection system of each building in Guangzhou and the optimal rainwater collection capacity distribution of the rainwater collection system of buildings in each district are shown in the figure below: Figure 2 shown

[0090] In this embodiment, the reduced domestic water supply volume V for a single building is calculated based on the optimal rainwater collection capacity. save , the expression is:

[0091] V save =min(v r+d2×t r ,D eff )

[0092] Among them, t r is the duration of rainfall, d2 is the water consumption rate during the rainfall period, and when it is in the rainfall period, the rainwater collection system directly collects rainwater to meet the water demand during the rainfall period.

[0093] Specifically, the distribution map of the average reduction in water supply for each building in Guangzhou is as follows: Figure 3 shown.

[0094] In this embodiment, the buildings using rainwater collection units in the city are counted and the power consumption W reduced due to the reduction of domestic water supply is calculated. save , the expression is:

[0095]

[0096] Where N is the total number of buildings using rainwater harvesting units in the city, I is the total number of independent rainfall events, and EH is the average electricity consumption per cubic meter of water provided by the water supply system.

[0097] In this embodiment, the calculation of the carbon emissions reduced due to the reduction in power consumption is save , the expression is:

[0098]

[0099] in, It is the recommended value of carbon emission factor, which is used to measure the carbon dioxide emitted for each kilowatt-hour of electricity. It is the global warming potential coefficient of carbon dioxide, which is used to convert the emissions of various greenhouse gases into carbon dioxide emissions.

[0100] Specifically, the recommended average carbon dioxide emission factors for electricity in each province are shown in Table 1.

[0101] Table 1

[0102]

[0103]

[0104] Example 3

[0105] This embodiment proposes an energy-saving and carbon-reduction assessment system based on an urban rainwater collection system. Figure 4 ,include:

[0106] The rainfall event segmentation module is used to obtain rainfall records of a city over the past three years and segment the rainfall records into discrete rainfall events;

[0107] The effective rainfall depth calculation module is used to obtain the average effective rainwater collection area and runoff coefficient on the top of a single building in the city, and combine it with the rainfall depth of a single rainfall event to calculate the effective rainfall depth of a single building in a single rainfall event;

[0108] The water supply and demand balance reliability calculation module is used to obtain the water consumption rate during the dry period and the water consumption rate during the rainy period in a single building, establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and use the water supply and demand balance reliability model to solve the water supply and demand balance reliability of the rainwater collection system;

[0109] The water supply calculation module is used to calculate the optimal rainwater collection capacity that meets the water supply and demand balance reliability of the rainwater collection system when the water supply and demand balance reliability of the rainwater collection system reaches a set threshold. Based on the optimal rainwater collection capacity, the reduced domestic water supply of a single building is calculated;

[0110] The electricity consumption and carbon emissions accounting module is used to count the buildings in the city that use rainwater collection systems, calculate the reduced electricity consumption due to the reduction in domestic water supply, and obtain the reduced carbon emissions due to the reduced electricity consumption.

[0111] In this embodiment, the process of segmenting rainfall records into discrete rainfall events is as follows:

[0112] Rainfall records whose rainfall depth did not reach the low rainfall threshold were eliminated;

[0113] Determine whether the rainfall depth of a rainfall event is less than the rainfall depth threshold. If so, merge the rainfall event into the rainfall event with the closest rainfall time and a rainfall depth greater than or equal to the rainfall depth threshold. If the rainfall depth is greater than or equal to the rainfall depth threshold, treat it as an independent rainfall event and segment it.

[0114] Determine whether the time interval between two rainfall events is less than the set minimum time interval. If so, merge the two consecutive rainfall events into one independent rainfall event. If the time interval between two rainfall events is greater than or equal to the set minimum time interval, separate the two rainfall records into two independent rainfall events.

[0115] Specifically, low rainfall threshold = 0.1 mm, rainfall depth threshold = 50 mm, and minimum time interval = 6 hours.

[0116] In this embodiment, after dividing the rainfall record into discrete rainfall events, the method further includes designing a probability density function obeyed by random variables of the dry period duration, rainfall duration, and rainfall depth of a single rainfall event in the rainfall record and calculating parameters of the probability density function;

[0117] The method used to calculate the parameters of the probability density function is the maximum likelihood estimation method, and the process is:

[0118] Calculate the duration of the drought period t for all independent rainfall events within three years n , rainfall duration t r and rainfall depth d r The mean of

[0119] Take the duration of drought period t n , rainfall duration t r and rainfall depth d r The inverse of the mean of the drought period is obtained as t n The random variable T n The probability density function of the rate parameter ψ, rainfall duration t r The random variable T r The probability density function of the rate parameter ξ, rainfall depth d r The random variable D r The rate parameter λ of the probability density function;

[0120] The probability density function P obeyed by the random variables of the three rainfall characteristic indicators is designed r , the expressions are:

[0121]

[0122] Among them, P r (T n =t n ) is the duration of the drought period t n The random variable T n The probability density function, P r (T r =t r ) is the rainfall duration t r The random variable T r The probability density function, P r (D r =d r ) is the rainfall depth d r The random variable D r The probability density function of .

[0123] In this embodiment, the vertical projection area of the building top from which rainwater can be collected is taken as the average effective rainwater collection area α on the top of a single building, and the proportion of rainfall converted into runoff is taken as the runoff coefficient. Calculate the effective rainfall depth D of a single building in a single rainfall event eff , the calculation expression is:

[0124]

[0125] Among them, D r is the rainfall depth d r The random variable d f The depth of the first flush of rainfall.

[0126] In this embodiment, the average hourly water consumption during non-rainfall periods is used as the water consumption rate d1 of a single building during the dry period, the average hourly water consumption during rainfall periods is used as the water consumption rate d2 of a single building during the rainfall period, and the average proportion of time during which the rainwater collected in the rainwater collection system of a single building meets the total water demand during all rainwater collection cycles is used as the water supply and demand balance reliability r of the rainwater collection system of a single building. A water supply and demand balance reliability model of the rainwater collection system of a single building is established, and the expression is:

[0127]

[0128] Where v represents the rainwater storage capacity of the rainwater collection system of a single building, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

[0129] In this embodiment, the calculation satisfies the optimal rainwater collection capacity v that satisfies the reliability of the water supply and demand balance of the rainwater collection system. r , the expression is:

[0130]

[0131] Where α represents the average effective rainwater collection area on the top of a single building, represents the runoff coefficient, d1 represents the water consumption rate in a single building during the dry period, d2 represents the water consumption rate in a single building during the rainy period, r represents the reliability of the water supply and demand balance of the rainwater collection system of a single building, and ψ represents the duration of the dry period t n The random variable T n The rate parameter of the probability density function, ξ represents the duration of rainfall t r The random variable T n The rate parameter of the probability density function, λ represents the rainfall depth d r The random variable D r The rate parameter of the probability density function, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

[0132] In this embodiment, the reduced domestic water supply volume V for a single building is calculated based on the optimal rainwater collection capacity. save , the expression is:

[0133] Vsave =min(v r +d2×t r ,D eff )

[0134] Among them, t r is the duration of rainfall, d2 is the water consumption rate during the rainfall period, and when it is in the rainfall period, the rainwater collection system directly collects rainwater to meet the water demand during the rainfall period.

[0135] In this embodiment, the buildings using rainwater collection units in the city are counted and the power consumption W reduced due to the reduction of domestic water supply is calculated. save , the expression is:

[0136]

[0137] Where N is the total number of buildings using rainwater harvesting units in the city, I is the total number of independent rainfall events, and EH is the average electricity consumption per cubic meter of water provided by the water supply system.

[0138] In this embodiment, the calculation of the carbon emissions reduced due to the reduction in power consumption is save , the expression is:

[0139]

[0140] in, It is the recommended value of carbon emission factor, which is used to measure the carbon dioxide emitted for each kilowatt-hour of electricity. It is the global warming potential coefficient of carbon dioxide, which is used to convert the emissions of various greenhouse gases into carbon dioxide emissions.

[0141] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for energy conservation and carbon reduction assessment based on urban rainwater collection system, characterized in that: The following steps are involved: Obtain rainfall records for a city within a T-time period and divide the rainfall records into discrete rainfall events; The average effective rainwater collection area and runoff coefficient of the top of a single building in the city are obtained, and combined with the rainfall depth of a single rainfall event, the effective rainfall depth of a single building in a single rainfall event is calculated; Obtain the water consumption rate during the dry period and the water consumption rate during the rainy period within a single building, establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and use the water supply and demand balance reliability model to solve the water supply and demand balance reliability of the rainwater collection system; When the reliability of the water supply and demand balance of the rainwater collection system reaches the set threshold, the optimal rainwater collection capacity that meets the reliability of the water supply and demand balance of the rainwater collection system is calculated. Based on the optimal rainwater collection capacity, the reduced domestic water supply of a single building is calculated; Count the buildings in the city that use rainwater collection systems, calculate the reduced electricity consumption due to the reduction in domestic water supply, and obtain the reduced carbon emissions due to the reduced electricity consumption.

2. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 1 is characterized in that: The process of segmenting rainfall records into discrete rainfall events is as follows: Rainfall records whose rainfall depth did not reach the low rainfall threshold were eliminated; Determine whether the rainfall depth of a rainfall event is less than the rainfall depth threshold. If so, merge the rainfall event into the rainfall event with the closest rainfall time and a rainfall depth greater than or equal to the rainfall depth threshold. If the rainfall depth is greater than or equal to the rainfall depth threshold, treat it as an independent rainfall event and segment it. Determine whether the time interval between two rainfall events is less than the set minimum time interval. If so, merge the two consecutive rainfall events into one independent rainfall event. If the time interval between two rainfall events is greater than or equal to the set minimum time interval, separate the two rainfall records into two independent rainfall events.

3. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 2 is characterized in that: After dividing the rainfall record into discrete rainfall events, the method further includes designing a probability density function obeyed by random variables of dry period duration, rainfall duration and rainfall depth of a single rainfall event in the rainfall record and calculating parameters of the probability density function; The method used to calculate the parameters of the probability density function is the maximum likelihood estimation method, and the process is: Calculate the dry period duration t of all independent rainfall events in the time period T n , rainfall duration t r and rainfall depth d r The mean of Take the duration of drought period t n , rainfall duration t r and rainfall depth d r The inverse of the mean of the drought period is obtained as t n The random variable T n The probability density function of the rate parameter ψ, rainfall duration t r The random variable T r The probability density function of the rate parameter ξ, rainfall depth d r The random variable D r The rate parameter λ of the probability density function; The probability density function P obeyed by the random variables of the three rainfall characteristic indicators is designed r , the expressions are: Among them, P r (T n =t n ) is the duration of the drought period t n The random variable T n The probability density function, P r (T r =t r ) is the rainfall duration t r The random variable T r The probability density function, P r (D r =d r ) is the rainfall depth d r The random variable D r The probability density function of .

4. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 3 is characterized in that: The vertical projection area of the building top from which rainwater can be collected is taken as the average effective rainwater collection area α on the top of a single building, and the proportion of rainfall converted into runoff is taken as the runoff coefficient. Calculate the effective rainfall depth D of a single building in a single rainfall event eff , the calculation expression is: Among them, D r is the rainfall depth d r The random variable d f The depth of the first flush of rainfall.

5. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 4 is characterized in that: The average hourly water consumption during non-rainfall periods is taken as the water consumption rate d1 of a single building during the dry period, the average hourly water consumption during rainfall periods is taken as the water consumption rate d2 of a single building during the rainfall period, and the average proportion of time during which the rainwater collected in the rainwater collection system of a single building meets the total water demand in all rainwater collection cycles is taken as the water supply and demand balance reliability r of the rainwater collection system of a single building. A water supply and demand balance reliability model of the rainwater collection system of a single building is established, which is expressed as follows: Where v represents the rainwater storage capacity of the rainwater collection system of a single building, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

6. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 5 is characterized in that: The calculation satisfies the optimal rainwater collection capacity v of the rainwater collection system to meet the water supply and demand balance reliability. r , the expression is: Where α represents the average effective rainwater collection area on the top of a single building, represents the runoff coefficient, d1 represents the water consumption rate in a single building during the dry period, d2 represents the water consumption rate in a single building during the rainy period, r represents the reliability of the water supply and demand balance of the rainwater collection system of a single building, and ψ represents the duration of the dry period t n The random variable T n The rate parameter of the probability density function, ξ represents the duration of rainfall t r The random variable T n The rate parameter of the probability density function, λ represents the rainfall depth d r The random variable D r The rate parameter of the probability density function, d f Indicates the first flushing depth of the top of a single building during a rainfall event.

7. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 6 is characterized in that: Based on the optimal rainwater collection capacity, the reduced domestic water supply V for a single building is calculated. save , the expression is: V save =min(v r +d2×t r ,D eff ) Among them, t r is the duration of rainfall, d2 is the water consumption rate during the rainfall period, and when it is in the rainfall period, the rainwater collection system directly collects rainwater to meet the water demand during the rainfall period.

8. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 7 is characterized in that: The statistics of buildings using rainwater collection units in the city are used to calculate the reduction in electricity consumption W due to the reduction in domestic water supply. save , the expression is: Where N is the total number of buildings using rainwater harvesting units in the city, I is the total number of independent rainfall events, and EH is the average electricity consumption per cubic meter of water provided by the water supply system.

9. The energy conservation and carbon reduction assessment method based on the urban rainwater collection system according to claim 8 is characterized in that: The calculation above shows the reduction in carbon emissions E due to the reduction in electricity consumption. save , the expression is: in, It is the recommended value of carbon emission factor, which is used to measure the carbon dioxide emitted for each kilowatt-hour of electricity. It is the global warming potential coefficient of carbon dioxide, which is used to convert the emissions of various greenhouse gases into carbon dioxide emissions.

10. An energy-saving and carbon-reduction assessment system based on an urban rainwater collection system, characterized in that: The system is used to implement the method according to any one of claims 1 to 9, comprising: The rainfall event segmentation module is used to obtain rainfall records within a certain city within a period of T and segment the rainfall records into discrete rainfall events; The effective rainfall depth calculation module is used to obtain the average effective rainwater collection area and runoff coefficient on the top of a single building in the city, and combine it with the rainfall depth of a single rainfall event to calculate the effective rainfall depth of a single building in a single rainfall event; The water supply and demand balance reliability calculation module is used to obtain the water consumption rate during the dry period and the water consumption rate during the rainy period in a single building, establish a water supply and demand balance reliability model for the rainwater collection system of a single building, and use the water supply and demand balance reliability model to solve the water supply and demand balance reliability of the rainwater collection system; The water supply calculation module is used to calculate the optimal rainwater collection capacity that meets the water supply and demand balance reliability of the rainwater collection system when the water supply and demand balance reliability of the rainwater collection system reaches a set threshold. Based on the optimal rainwater collection capacity, the reduced domestic water supply of a single building is calculated; The electricity consumption and carbon emissions accounting module is used to count the buildings in the city that use rainwater collection systems, calculate the reduced electricity consumption due to the reduction in domestic water supply, and obtain the reduced carbon emissions due to the reduced electricity consumption.

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