A Design Method and Device for Preventing Water Backflow and Water Cross-Flow in a Water Circuit without a Return Water Pipe

Abstract

The present application relates to the technical field of gas water heaters, and particularly to a design method and device for preventing water cross-flow in a water circuit without a return pipe. The method includes: obtaining the resistance values of the target cold water pipe, the target hot water pipe, the target water heater, and the target check valve in the to-be-installed zero-cold-water system without a return pipe; establishing a simulation model according to the relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet pre-stored; for each total water flow rate among the total water flow rates, inputting the total water flow rate into the simulation model, and outputting the pressure drop value of the check valve corresponding to the total water flow rate; performing linear fitting processing to obtain the corresponding relationship between the pressure drop value corresponding to the check valve and the total water flow rate; according to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe, querying the pressure drop value corresponding to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe, and using it as the critical pressure drop value corresponding to the to-be-installed zero-cold-water system without a return pipe. Using the present application can prevent water cross-flow.

Description

Technical Field

[0001] The present application relates to the technical field of gas water heaters, and particularly to a waterway anti-crossing design method and device for a waterway without a return pipe. Background Art

[0002] At present, the waterway without a return pipe consists of a cold water pipe, a hot water pipe, a water heater with a circulating pump, and a check valve. The check valve is set at the farthest end of the hot water usage point and connected to the cold water pipe, so that the gas water heater, the hot water pipeline, the check valve pipeline, and the cold water pipe form a circulating pipeline. The cold water in the circulating waterway is preheated inside the water heater by the circulating pump in advance, realizing hot water output immediately after startup and improving the bathing comfort of consumers.

[0003] Although the existing waterway without a return pipe meets the hot water demand of users without a return pipe, when the user does not use hot water, such as when opening the cold water switch, flushing the toilet or using the washing machine, the pressure in the cold water pipe drops instantaneously. If the resistance characteristic of the check valve cannot resist the water pressure, the water in the hot water pipe will push open the check valve and flow into the cold water pipe. At this time, after the gas water heater detects that the water flow in the hot water pipe exceeds the startup water flow of the water heater, it starts, resulting in the occurrence of water crossing. This situation not only wastes gas but also brings unnecessary troubles to users. Therefore, how to select a suitable check valve for different waterways without a return pipe has become an urgent problem to be solved. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a waterway anti-crossing design method and device for a waterway without a return pipe.

[0005] In a first aspect, a waterway anti-crossing design method for a waterway without a return pipe is provided. The method includes:

[0006] Obtain the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve in the zero-cold-water system without a return pipe to be installed;

[0007] According to the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve, and the relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet stored in advance, establish a simulation model;

[0008] For each total water flow rate among the total water flow rates, input the total water flow rate into the simulation model, and output the pressure drop value of the check valve corresponding to the total water flow rate;

[0009] Perform linear fitting on the pressure drop values of the check valve corresponding to the total water flow rates to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate;

[0010] According to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe, query the pressure drop value corresponding to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe in the corresponding relationship between the pressure drop value corresponding to the one-way valve and the total water flow rate, and use this pressure drop value as the critical pressure drop value corresponding to the to-be-installed zero-cold-water system without a return pipe.

[0011] As an alternative implementation, the obtaining of the cold water pipe resistance value, the hot water pipe resistance value, the water heater resistance value, and the one-way valve resistance value in the to-be-installed zero-cold-water system without a return pipe includes:

[0012] In the pre-stored corresponding relationship between the cold water pipe length and the cold water pipe resistance, query the cold water pipe resistance value corresponding to the cold water pipe length in the to-be-installed zero-cold-water system without a return pipe;

[0013] In the pre-stored corresponding relationship between the hot water pipe length and the hot water pipe resistance, query the hot water pipe resistance value corresponding to the hot water pipe length in the to-be-installed zero-cold-water system without a return pipe;

[0014] In the pre-stored corresponding relationship between the water heater volume and the water heater resistance, query the water heater resistance value corresponding to the water heater volume in the to-be-installed zero-cold-water system without a return pipe;

[0015] In the pre-stored corresponding relationship between the one-way valve model and the one-way valve resistance, query the one-way valve resistance value corresponding to the one-way valve model in the to-be-installed zero-cold-water system without a return pipe.

[0016] As an alternative implementation, the establishing of a simulation model according to the cold water pipe resistance value, the hot water pipe resistance value, the water heater resistance value, the one-way valve resistance value, and the pre-stored relative positions of the cold water pipe, the hot water pipe, the water heater, the one-way valve, the water inlet, and the water outlet includes:

[0017] Based on the fluid simulation software FLUENT, determine the cold water pipe resistance element, the hot water pipe resistance element, the water heater resistance element, and the one-way valve resistance element with equal resistance according to the input cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, and one-way valve resistance value;

[0018] Establish a simulation model according to the pre-stored relative positions of the cold water pipe, the hot water pipe, the water heater, the one-way valve, the water inlet, and the water outlet and the cold water pipe resistance element, the hot water pipe resistance element, the water heater resistance element, and the one-way valve resistance element.

[0019] As an alternative implementation, for each total water flow rate among the total water flow rates, inputting this total water flow rate into the simulation model and outputting the pressure drop value of the one-way valve corresponding to this total water flow rate includes:

[0020] For each of the total water flow rates, according to the total water flow rate input to the simulation model, output the water flow velocity of the one-way valve resistance element and the pressure drop value corresponding to the water flow velocity, and use this pressure drop value as the pressure drop value of the one-way valve corresponding to this total water flow rate.

[0021] As an optional implementation manner, the method further includes:

[0022] Input a test total water flow rate;

[0023] Obtain the water flow rate of the first hot water pipe of the actual model established based on the simulation model and the first overall pressure drop value between the water inlet and the water outlet;

[0024] Obtain the water flow rate of the second hot water pipe of the simulation model and the second overall pressure drop value between the water inlet and the water outlet;

[0025] Calculate the difference in water flow rate between the water flow rate of the first hot water pipe and the water flow rate of the second hot water pipe, and the difference in pressure drop between the first overall pressure drop value and the second overall pressure drop value;

[0026] If the absolute value of the ratio of the water flow rate difference to the water flow rate of the second hot water pipe is less than or equal to a preset first accuracy threshold, and the absolute value of the ratio of the pressure drop difference to the second overall pressure drop value is less than or equal to a preset second accuracy threshold, then the simulation model meets the preset accuracy requirements.

[0027] In a second aspect, there is provided a device for preventing water backflow in a water circuit without a return pipe, the device including:

[0028] A first acquisition module, configured to acquire the cold water pipe resistance value, the hot water pipe resistance value, the water heater resistance value, and the one-way valve resistance value in the zero-cold-water system to be installed without a return pipe;

[0029] A building module, configured to build a simulation model according to the cold water pipe resistance value, the hot water pipe resistance value, the water heater resistance value, the one-way valve resistance value, and the relative positions of the cold water pipe, the hot water pipe, the water heater, the one-way valve, the water inlet, and the water outlet stored in advance;

[0030] An output module, configured to input each total water flow rate among the total water flow rates into the simulation model and output the pressure drop value of the one-way valve corresponding to this total water flow rate;

[0031] A first processing module, configured to perform a linear fitting process on the pressure drop values of the one-way valves corresponding to the total water flow rates to obtain the corresponding relationship between the pressure drop values corresponding to the one-way valves and the total water flow rates;

[0032] A second processing module, configured to query, according to the maximum total water flow rate of the to-be-installed zero cold water system without a return water pipe, the pressure drop value corresponding to the maximum total water flow rate of the to-be-installed zero cold water system without a return water pipe in the corresponding relationship between the pressure drop value corresponding to the one-way valve and the total water flow rate, and use this pressure drop value as the critical pressure drop value corresponding to the to-be-installed zero cold water system without a return water pipe.

[0033] As an optional implementation manner, the obtaining module is specifically configured to:

[0034] Query, in the corresponding relationship between the cold water pipe length and the cold water pipe resistance stored in advance, the cold water pipe resistance value corresponding to the cold water pipe length in the to-be-installed zero cold water system without a return water pipe;

[0035] Query, in the corresponding relationship between the hot water pipe length and the hot water pipe resistance stored in advance, the hot water pipe resistance value corresponding to the hot water pipe length in the to-be-installed zero cold water system without a return water pipe;

[0036] Query, in the corresponding relationship between the water heater volume and the water heater resistance stored in advance, the water heater resistance value corresponding to the water heater volume in the to-be-installed zero cold water system without a return water pipe;

[0037] Query, in the corresponding relationship between the one-way valve model and the one-way valve resistance stored in advance, the one-way valve resistance value corresponding to the one-way valve model in the to-be-installed zero cold water system without a return water pipe.

[0038] As an optional implementation manner, the establishing module is specifically configured to:

[0039] Based on the fluid simulation software FLUENT, determine cold water pipe resistance elements, hot water pipe resistance elements, water heater resistance elements, and one-way valve resistance elements with equal resistance according to the input cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, and one-way valve resistance value;

[0040] Establish a simulation model according to the relative positions of the cold water pipe, hot water pipe, water heater, one-way valve, water inlet, and water outlet stored in advance and the cold water pipe resistance elements, hot water pipe resistance elements, water heater resistance elements, and one-way valve resistance elements.

[0041] As an optional implementation manner, the output module is specifically configured to:

[0042] For each total water flow rate among the total water flow rates, according to the total water flow rate input to the simulation model, output the water flow velocity of the one-way valve resistance element and the pressure drop value corresponding to the water flow velocity, and use this pressure drop value as the pressure drop value of the one-way valve corresponding to this total water flow rate.

[0043] As an optional implementation manner, the device further includes:

[0044] An input module for inputting the total test water flow rate;

[0045] A second acquisition module for acquiring the water flow rate of the first hot water pipe of the actual model established based on the simulation model and the first overall pressure drop value between the water inlet and the water outlet;

[0046] A third acquisition module for acquiring the water flow rate of the second hot water pipe of the simulation model and the second overall pressure drop value between the water inlet and the water outlet;

[0047] A third processing module for calculating the water flow rate difference between the water flow rate of the first hot water pipe and the water flow rate of the second hot water pipe, and the pressure drop difference between the first overall pressure drop value and the second overall pressure drop value;

[0048] A fourth processing module for determining that the simulation model meets the preset accuracy requirement if the absolute value of the ratio of the water flow rate difference to the water flow rate of the second hot water pipe is less than or equal to a preset first accuracy threshold, and the absolute value of the ratio of the pressure drop difference to the second overall pressure drop value is less than or equal to a preset second accuracy threshold.

[0049] In a third aspect, a computer device is provided, including a memory and a processor. A computer program is stored on the memory and can run on the processor. When the processor executes the computer program, the method steps described in any item of the first aspect are implemented.

[0050] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method steps described in any item of the first aspect are implemented.

[0051] The present application provides a waterway anti-crossing water design method and device for a water system without a return pipe. The technical solutions provided by the embodiments of the present application at least bring the following beneficial effects: obtaining the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve in the to-be-installed zero-cold-water system without a return pipe; establishing a simulation model according to the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve, and the relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet prestored; for each total water flow rate among the total water flow rates, inputting the total water flow rate into the simulation model, and outputting the pressure drop value of the check valve corresponding to the total water flow rate; performing linear fitting processing on the pressure drop values of the check valve corresponding to the total water flow rates to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate; according to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe, querying the pressure drop value corresponding to the maximum total water flow rate of the to-be-installed zero-cold-water system in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate, and taking this pressure drop value as the critical pressure drop value corresponding to the to-be-installed zero-cold-water system. The present application simplifies the zero-cold-water pipeline of a household without a return pipe into a simplified model including a cold water pipe resistance unit, a hot water pipe resistance unit, a water heater resistance unit, a check valve resistance unit, a water inlet, and a water outlet, and based on the simplified model, uses fluid simulation software to establish a simulation model. Based on the simulation model, the flow velocities and pressure drops of the water heater, the cold and hot water pipes, and the check valve under different working conditions are obtained, fitted into flow velocity and pressure drop curves, and then fitted into the check valve design critical curves under different pipelines and different total water flow rates. When selecting a check valve, the check valve matching the zero-cold-water pipeline of a household without a return pipe can be selected according to the check valve design critical curves under different pipelines and different total water flow rates to effectively prevent the occurrence of the "crossing water" problem.

[0052] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0054] Figure 1 It is a flowchart of a waterway anti-crossing water design method provided by an embodiment of the present application;

[0055] Figure 2 It is a schematic diagram of a simplified model provided by an embodiment of the present application;

[0056] Figure 3 Flow chart of a method for judging the accuracy of a simulation model provided by an embodiment of the present application;

[0057] Figure 4 Structural schematic diagram of a non-return water pipe water path anti-water backflow design device provided by an embodiment of the present application;

[0058] Figure 5 Schematic diagram of a one-way valve critical pressure drop value curve under different pipelines and total water flow rates provided by an embodiment of the present application;

[0059] Figure 6 Structural schematic diagram of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0060] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

[0061] Next, a non-return water pipe water path anti-water backflow design method provided by an embodiment of the present application will be described in detail in combination with the specific implementation manners. Figure 1 Flow chart of a non-return water pipe water path anti-water backflow design method provided by an embodiment of the present application, as Figure 1 shown, the specific steps are as follows:

[0062] Step 101, obtain the resistance values of the cold water pipe, the hot water pipe, the water heater and the one-way valve in the to-be-installed non-return water pipe zero-cold water system.

[0063] In implementation, the to-be-installed non-return water pipe zero-cold water system includes a water heater with a preset volume, several types of one-way valves, a cold water pipe and a hot water pipe with a preset length. Technicians determine the resistance values and the resistance and pressure drop characteristics of the water heater, several types of one-way valves, the cold water pipe and the hot water pipe with a preset length through tests, and input them into a computer. The computer obtains the resistance values of the cold water pipe, the hot water pipe, the water heater and the one-way valve in the to-be-installed non-return water pipe zero-cold water system according to the cold water pipe length, the hot water pipe length, the water heater volume and the one-way valve model.

[0064] Optionally, the specific steps for the computer to obtain the resistance values of the cold water pipe, the hot water pipe, the water heater and the one-way valve in the to-be-installed non-return water pipe zero-cold water system are as follows:

[0065] In the corresponding relationship between the cold water pipe length and the cold water pipe resistance stored in advance, query the cold water pipe resistance value corresponding to the cold water pipe length in the to-be-installed non-return water pipe zero-cold water system;

[0066] In the pre-stored correspondence between the length of the hot water pipe and the resistance of the hot water pipe, query the resistance value of the hot water pipe corresponding to the length of the hot water pipe in the zero cold water system without a return pipe to be installed;

[0067] In the pre-stored correspondence between the volume of the water heater and the resistance of the water heater, query the resistance value of the water heater corresponding to the volume of the water heater in the zero cold water system without a return pipe to be installed;

[0068] In the pre-stored correspondence between the model number of the check valve and the resistance of the check valve, query the resistance value of the check valve corresponding to the model number of the check valve in the zero cold water system without a return pipe to be installed.

[0069] In implementation, technicians conduct experiments on cold and hot water pipes of different lengths, different types of check valves, and water heaters of different volumes to determine the correspondence between the length of the cold water pipe and the resistance of the cold water pipe, the correspondence between the length of the hot water pipe and the resistance of the hot water pipe, the correspondence between the volume of the water heater and the resistance of the water heater, and the correspondence between the model number of the check valve and the resistance of the check valve, and input them into the computer so that the computer can determine the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve according to the actual situation of the zero cold water system without a return pipe to be installed.

[0070] Step 102, establish a simulation model according to the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve, and the pre-stored relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet.

[0071] In implementation, since the real zero cold water pipeline without a return pipe in a household is very complex, if modeling is based on the real zero cold water pipeline without a return pipe, the calculation amount is huge. And problems such as the roughness of the pipeline wall surface, the machining accuracy of the adapter, and the dripping of some local pipelines will have a great impact on the calculation accuracy. Therefore, the computer equivalently generates corresponding resistance units in the simulation software according to the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve, namely, the cold water pipeline resistance unit, the hot water pipeline resistance unit, the water heater resistance unit, and the check valve resistance unit. The computer establishes a simplified model corresponding to the real zero cold water pipeline without a return pipe according to each resistance unit and the pre-stored relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet, and establishes a simulation model based on the simplified model. Figure 2 It is a schematic diagram of a simplified model provided by an embodiment of the present application, as Figure 2 shown, where 210 is the water outlet, 220 is the cold water pipeline resistance unit, 230 is the check valve resistance unit, 240 is the water inlet, 250 is the water heater resistance unit, and 260 is the hot water pipeline resistance unit.

[0072] Optionally, the specific steps for the computer to establish a simulation model based on the cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, check valve resistance value, and the pre-stored relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet are as follows:

[0073] Based on the fluid simulation software FLUENT, determine the cold water pipe resistance element, hot water pipe resistance element, water heater resistance element, and check valve resistance element with equal resistance according to the input cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, and check valve resistance value;

[0074] Establish a simulation model according to the pre-stored relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet and the cold water pipe resistance element, hot water pipe resistance element, water heater resistance element, and check valve resistance element.

[0075] Step 103, for each total water flow rate among the total water flow rates, input the total water flow rate into the simulation model and output the pressure drop value of the check valve corresponding to the total water flow rate.

[0076] In implementation, the computer, for each total water flow rate among the total water flow rates, inputs the total water flow rate into the simulation model and outputs the pressure drop value of the check valve corresponding to the total water flow rate.

[0077] Step 104, perform linear fitting on the pressure drop values of the check valve corresponding to the total water flow rates to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate.

[0078] In implementation, the computer performs linear fitting on the pressure drop values of the check valve corresponding to the total water flow rates to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate.

[0079] Step 105, according to the maximum total water flow rate of the zero cold water system without a return pipe to be installed, query the pressure drop value corresponding to the maximum total water flow rate of the zero cold water system without a return pipe to be installed in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate, and use this pressure drop value as the critical pressure drop value corresponding to the zero cold water system without a return pipe to be installed.

[0080] In implementation, the computer, according to the maximum total water flow rate of the zero cold water system without a return pipe to be installed, queries the pressure drop value corresponding to the maximum total water flow rate of the zero cold water system without a return pipe to be installed in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate, and uses this pressure drop value as the critical pressure drop value corresponding to the zero cold water system without a return pipe to be installed. Figure 5 This is a schematic diagram of the critical pressure drop value curve of the check valve under different pipelines and total water flow rates provided by the embodiment of the present application. As Figure 5As shown in the figure, taking the water heater volume as fixed and the cold and hot water pipes having the same length as an example, when both the cold and hot water pipes are 15 meters long, according to this figure, the critical pressure drop values of the check valve corresponding to each total water flow rate on the curve corresponding to the 15-meter-long cold and hot water pipes can be determined, and the computer can output these critical pressure drop values so that users or technicians can select a check valve with a pressure drop value higher than this critical pressure drop value when selecting a check valve, thereby meeting the requirements of the one-way valve opening pressure (pressure drop value) of the zero cold water system without a return pipe in the home and effectively preventing the occurrence of water cross-flow.

[0081] Optionally, according to the method provided in this application, a simulation model can also be established based on the unequal lengths of the cold and hot water pipes or different volumes of the water heater, and then the relationship curve between the pressure drop value of the check valve and the total water flow rate corresponding to cold and hot water pipes of different lengths or water heaters can be obtained to meet the requirements of check valve selection.

[0082] As an optional implementation manner, for each total water flow rate among the total water flow rates, the specific steps of inputting this total water flow rate into the simulation model and outputting the pressure drop value of the check valve corresponding to this total water flow rate are as follows:

[0083] For each total water flow rate among the total water flow rates, according to this total water flow rate input into the simulation model, output the water flow velocity of the water flow resistance element of the check valve and the pressure drop value corresponding to the water flow velocity, and use this pressure drop value as the pressure drop value of the check valve corresponding to this total water flow rate.

[0084] As an optional implementation manner, Figure 3 is a flowchart of a method for judging the accuracy of the simulation model provided by the embodiment of this application. As Figure 3 shown, the specific steps for the computer to determine whether the accuracy of the simulation model meets the preset accuracy requirements are as follows:

[0085] Step 301, input the test total water flow rate;

[0086] Step 302, obtain the first hot water pipe water flow rate of the actual model established based on the simulation model and the first overall pressure drop value between the water inlet and the water outlet;

[0087] Step 303, obtain the second hot water pipe water flow rate of the simulation model and the second overall pressure drop value between the water inlet and the water outlet;

[0088] Step 304, calculate the difference in water flow rate between the first hot water pipe water flow rate and the second hot water pipe water flow rate, and the difference in pressure drop between the first overall pressure drop value and the second overall pressure drop value;

[0089] In step 305, if the absolute value of the ratio of the water flow difference to the water flow of the second hot water pipe is less than or equal to a preset first precision threshold, and the absolute value of the ratio of the pressure drop difference to the second overall pressure drop value is less than or equal to a preset second precision threshold, the simulation model meets the preset precision requirements.

[0090] In implementation, Table 1 is a data table for testing the precision of a simulation model provided in this embodiment, as shown in Table 1:

[0091] Table 1

[0092] Total flow rate L / min Water flow rate of the first hot water pipe L / min Water flow rate of the second hot water pipe L / min Accuracy First overall pressure drop value (Kpa) Second overall pressure drop value (Kpa) Accuracy 10.7540 2.7540 3.1326 12.1% 19.1 19.6 2.5% 12.4100 3.2433 3.6864 12.1% 24.4 25.2 3.2% 14.3660 4.0327 4.3320 6.9% 31.3 32.7 4.4% 16.1000 4.4333 4.9020 9.6% 38.1 40.2 5.3% 17.6160 4.9493 5.3964 8.3% 45.3 47.4 4.5% 19.0810 5.2477 5.8680 10.6% 52.5 54.9 4.5% 22.4960 6.4960 6.9780 6.9% 70.4 74.7 5.7% 24.5330 7.3663 7.6416 3.6% 80.1 87.9 9.1%

[0093] Among them, the total flow rate is the water flow rate input to the water inlet, the water flow rate of the first hot water pipe is the water flow rate of the hot water pipe measured based on the actual model, the water flow rate of the second hot water pipe is the water flow rate of the hot water pipe output based on the simulation model, the first overall pressure drop value is the pressure drop value between the water inlet and the water outlet measured based on the actual model, and the second overall pressure drop value is the pressure drop value between the water inlet and the water outlet measured based on the simulation model. According to Table 1, it can be obtained that the precision of the water flow rate of the hot water pipe is within 10%, and the precision of the overall pressure drop at the water inlet and outlet is within 5%. Then, the simulation model meets the preset precision requirements. If the preset precision requirements are not met, the flow velocity and pressure drop curves and binomials in the simulation model need to be modified again. The specific method is to fit new flow velocity and pressure drop curves and obtain polynomials.

[0094] An embodiment of the present application provides a method for preventing water cross-flow in a water circuit without a return pipe. Obtain the resistance values of the cold water pipe, hot water pipe, water heater, and check valve in the zero-cold-water system without a return pipe to be installed; establish a simulation model based on the resistance values of the cold water pipe, hot water pipe, water heater, and check valve, as well as the relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet pre-stored; for each total water flow rate among the total water flow rates, input the total water flow rate into the simulation model and output the pressure drop value of the check valve corresponding to the total water flow rate; perform a linear fitting process on the pressure drop values of the check valve corresponding to the total water flow rates to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate; according to the maximum total water flow rate of the zero-cold-water system without a return pipe to be installed, query the pressure drop value corresponding to the maximum total water flow rate of the zero-cold-water system without a return pipe in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate, and use this pressure drop value as the critical pressure drop value corresponding to the zero-cold-water system without a return pipe to be installed. The present application simplifies the zero-cold-water pipeline of a household without a return pipe into a simplified model including a cold water pipe resistance unit, a hot water pipe resistance unit, a water heater resistance unit, a check valve resistance unit, a water inlet, and a water outlet, and based on the simplified model, uses fluid simulation software to establish a simulation model. Based on the simulation model, obtain the flow velocity and pressure drop under different working conditions of the water heater, cold and hot water pipes, and check valve, fit them into a flow velocity-pressure drop curve, and then fit them into a critical design curve of the check valve under different pipelines and different total water flow rates. When selecting a check valve, a check valve matching the zero-cold-water pipeline of a household without a return pipe can be selected according to the critical design curve of the check valve under different pipelines and different total water flow rates to effectively prevent the occurrence of the "water cross-flow" problem.

[0095] It should be understood that although Figure 1 and Figure 3 the steps in the flowcharts of Figure 1 and Figure 3 are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover,

[0096] at least a part of the steps in

[0097] The embodiment of the present application further provides a water path anti-cross-flow design device without a return water pipe, as Figure 4 shown. The device includes:

[0098] A first acquisition module 410, configured to acquire the cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, and check valve resistance value in the zero cold water system without a return water pipe to be installed;

[0099] A building module 420, configured to build a simulation model according to the cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, check valve resistance value, and the relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet prestored;

[0100] An output module 430, configured to input each total water flow rate into the simulation model for each total water flow rate, and output the pressure drop value of the check valve corresponding to the total water flow rate;

[0101] A first processing module 440, configured to perform linear fitting processing on the pressure drop values of the check valve corresponding to each total water flow rate to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate;

[0102] A second processing module 450, configured to query the pressure drop value corresponding to the maximum total water flow rate of the zero cold water system without a return water pipe to be installed in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate according to the maximum total water flow rate of the zero cold water system without a return water pipe to be installed, and use the pressure drop value as the critical pressure drop value corresponding to the zero cold water system without a return water pipe to be installed.

[0103] As an optional implementation manner, the first acquisition module 410 is specifically configured to:

[0104] Query the cold water pipe resistance value corresponding to the cold water pipe length in the zero cold water system without a return water pipe to be installed in the corresponding relationship between the cold water pipe length and the cold water pipe resistance prestored;

[0105] Query the hot water pipe resistance value corresponding to the hot water pipe length in the zero cold water system without a return water pipe to be installed in the corresponding relationship between the hot water pipe length and the hot water pipe resistance prestored;

[0106] Query the water heater resistance value corresponding to the water heater volume in the zero cold water system without a return water pipe to be installed in the corresponding relationship between the water heater volume and the water heater resistance prestored;

[0107] Query the check valve resistance value corresponding to the check valve model in the zero cold water system without a return water pipe to be installed in the corresponding relationship between the check valve model and the check valve resistance prestored.

[0108] As an optional implementation manner, the building module 420 is specifically configured to:

[0109] Based on the fluid simulation software FLUENT, according to the input cold water pipe resistance value, hot water pipe resistance value, water heater resistance value and check valve resistance value, determine the cold water pipe resistance element, hot water pipe resistance element, water heater resistance element and check valve resistance element with equal resistance;

[0110] According to the relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet and water outlet stored in advance and the cold water pipe resistance element, hot water pipe resistance element, water heater resistance element and check valve resistance element, establish a simulation model.

[0111] As an optional implementation manner, the output module 430 is specifically used for:

[0112] For each total water flow rate among the total water flow rates, according to the total water flow rate input to the simulation model, output the water flow velocity of the check valve resistance element and the pressure drop value corresponding to the water flow velocity, and use the pressure drop value as the pressure drop value of the check valve corresponding to the total water flow rate.

[0113] As an optional implementation manner, the device further includes:

[0114] An input module 460, configured to input a test total water flow rate;

[0115] A second acquisition module 470, configured to acquire the first hot water pipe water flow rate of the actual model established based on the simulation model and the first overall pressure drop value between the water inlet and the water outlet;

[0116] A third acquisition module 480, configured to acquire the second hot water pipe water flow rate of the simulation model and the second overall pressure drop value between the water inlet and the water outlet;

[0117] A third processing module 490, configured to calculate the water flow rate difference between the first hot water pipe water flow rate and the second hot water pipe water flow rate, and the pressure drop difference between the first overall pressure drop value and the second overall pressure drop value;

[0118] A fourth processing module 4110, configured to determine that the simulation model meets the preset accuracy requirement if the absolute value of the ratio of the water flow rate difference to the second hot water pipe water flow rate is less than or equal to a preset first accuracy threshold, and the absolute value of the ratio of the pressure drop difference to the second overall pressure drop value is less than or equal to a preset second accuracy threshold.

[0119] The embodiment of the present application provides a water path anti-cross-flow design device without a return water pipe. Among them, the first acquisition module 410 is used to acquire the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve in the zero-cold-water system without a return water pipe to be installed; the establishment module 420 is used to establish a simulation model according to the resistance values of the cold water pipe, the hot water pipe, the water heater, and the check valve, and the relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet stored in advance; the first output module 430 is used to input each total water flow rate among the total water flow rates into the simulation model and output the pressure drop value of the check valve corresponding to the total water flow rate; the first processing module 440 is used to perform linear fitting processing on the pressure drop values of the check valve corresponding to each total water flow rate to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate; the second processing module 450 is used to query the pressure drop value corresponding to the maximum total water flow rate of the zero-cold-water system without a return water pipe to be installed in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate, and use this pressure drop value as the critical pressure drop value corresponding to the zero-cold-water system without a return water pipe to be installed. The present application simplifies the zero-cold-water pipe water path of a household without a return water pipe into a simplified model including a cold water pipe resistance unit, a hot water pipe resistance unit, a water heater resistance unit, a check valve resistance unit, a water inlet, and a water outlet. Based on the simplified model, a simulation model is established using fluid simulation software. Based on the simulation model, the flow rates and pressure drops of the water heater, cold and hot water pipes, and check valve under different working conditions are obtained, and the flow rate and pressure drop curves are fitted, and then the critical design curves of the check valve under different pipelines and different total water flow rates are fitted. When selecting a check valve, a check valve matching the zero-cold-water pipe water path of a household without a return water pipe can be selected according to the critical design curves of the check valve under different pipelines and different total water flow rates to effectively prevent the occurrence of the "cross-flow" problem.

[0120] For the specific limitations of the water path anti-cross-flow design device without a return water pipe, reference can be made to the limitations of the water path anti-cross-flow design method without a return water pipe in the above text, which will not be elaborated here. Each module in the above water path anti-cross-flow design device without a return water pipe can be implemented in whole or in part by software, hardware, and their combinations. The above modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0121] In one embodiment, a computer device is provided, as Figure 6 shown, including a memory and a processor. A computer program that can run on the processor is stored on the memory. When the processor executes the computer program, the method steps of the above water path anti-cross-flow design without a return water pipe are implemented.

[0122] In one embodiment, a computer-readable storage medium stores a computer program which, when executed by a processor, implements the steps of the method for preventing water backflow and water mixing in a water circuit without a return pipe as described above.

[0123] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in this application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0124] It should be noted that in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or device including a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article, or device including the said element.

[0125] It should also be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for display, data for analysis, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0126] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiment.

[0127] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0128] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A waterway anti-water backflow design method without a water return pipe, characterized in that The method includes: Obtaining the resistance values of the cold water pipe, hot water pipe, water heater, and check valve in the zero - cold - water system without a return water pipe to be installed; Establishing a simulation model based on the resistance values of the cold water pipe, hot water pipe, water heater, and check valve, and the relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet stored in advance; For each total water flow rate among the total water flow rates, inputting the total water flow rate into the simulation model and outputting the pressure drop value of the check valve corresponding to the total water flow rate; Performing linear fitting on the pressure drop values of the check valve corresponding to each total water flow rate to obtain the corresponding relationship between the pressure drop value of the check valve and the total water flow rate; According to the maximum total water flow rate of the zero - cold - water system without a return water pipe to be installed, querying the pressure drop value corresponding to the maximum total water flow rate of the zero - cold - water system without a return water pipe to be installed in the corresponding relationship between the pressure drop value of the check valve and the total water flow rate, and using this pressure drop value as the critical pressure drop value corresponding to the zero - cold - water system without a return water pipe to be installed; The establishing a simulation model based on the resistance values of the cold water pipe, hot water pipe, water heater, and check valve, and the relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet stored in advance includes: Based on the fluid simulation software FLUENT, determining the cold water pipe resistance element, hot water pipe resistance element, water heater resistance element, and check valve resistance element with equal resistance according to the input resistance values of the cold water pipe, hot water pipe, water heater, and check valve; Establishing a simulation model according to the relative positions of the cold water pipe, hot water pipe, water heater, check valve, water inlet, and water outlet stored in advance and the cold water pipe resistance element, hot water pipe resistance element, water heater resistance element, and check valve resistance element.

2. The method according to claim 1, wherein The obtaining the resistance values of the cold water pipe, hot water pipe, water heater, and check valve in the zero - cold - water system without a return water pipe to be installed includes: Querying the resistance value of the cold water pipe corresponding to the cold water pipe length in the zero - cold - water system without a return water pipe to be installed in the corresponding relationship between the cold water pipe length and the cold water pipe resistance stored in advance; Querying the resistance value of the hot water pipe corresponding to the hot water pipe length in the zero - cold - water system without a return water pipe to be installed in the corresponding relationship between the hot water pipe length and the hot water pipe resistance stored in advance; Querying the resistance value of the water heater corresponding to the water heater volume in the zero - cold - water system without a return water pipe to be installed in the corresponding relationship between the water heater volume and the water heater resistance stored in advance; Querying the resistance value of the check valve corresponding to the check valve model in the zero - cold - water system without a return water pipe to be installed in the corresponding relationship between the check valve model and the check valve resistance stored in advance.

3. The method according to claim 1, wherein The for each total water flow rate among the total water flow rates, inputting the total water flow rate into the simulation model and outputting the pressure drop value of the check valve corresponding to the total water flow rate includes: For each total water flow rate among the various total water flow rates, according to the total water flow rate input to the simulation model, output the water flow velocity of the check valve resistance element and the pressure drop value corresponding to the water flow velocity, and use this pressure drop value as the pressure drop value of the check valve corresponding to this total water flow rate.

4. The method according to claim 1, characterized in that, The method further includes: Input a test total water flow rate; Obtain the water flow rate of the first hot water pipe of the actual model established based on the simulation model and the first overall pressure drop value between the water inlet and the water outlet; Obtain the water flow rate of the second hot water pipe of the simulation model and the second overall pressure drop value between the water inlet and the water outlet; Calculate the difference in water flow rate between the water flow rate of the first hot water pipe and the water flow rate of the second hot water pipe, and the difference in pressure drop between the first overall pressure drop value and the second overall pressure drop value; If the absolute value of the ratio of the water flow rate difference to the water flow rate of the second hot water pipe is less than or equal to a preset first precision threshold, and the absolute value of the ratio of the pressure drop difference to the second overall pressure drop value is less than or equal to a preset second precision threshold, then the simulation model meets the preset precision requirements.

5. A waterway anti-cross-flow design device without a return water pipe, characterized in that The device includes: A first acquisition module, configured to acquire the cold water pipe resistance value, the hot water pipe resistance value, the water heater resistance value, and the check valve resistance value in the to-be-installed zero-cold-water system without a return pipe; A building module, configured to build a simulation model according to the cold water pipe resistance value, the hot water pipe resistance value, the water heater resistance value, the check valve resistance value, and the relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet stored in advance; An output module, configured to, for each total water flow rate among the various total water flow rates, input this total water flow rate to the simulation model and output the pressure drop value of the check valve corresponding to this total water flow rate; A first processing module, configured to perform linear fitting processing on the pressure drop values of the check valves corresponding to the various total water flow rates to obtain the corresponding relationship between the pressure drop value corresponding to the check valve and the total water flow rate; A second processing module, configured to, according to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe, query the pressure drop value corresponding to the maximum total water flow rate of the to-be-installed zero-cold-water system without a return pipe in the corresponding relationship between the pressure drop value corresponding to the check valve and the total water flow rate, and use this pressure drop value as the critical pressure drop value corresponding to the to-be-installed zero-cold-water system without a return pipe; The building module is specifically configured to: Based on the fluid simulation software FLUENT, according to the input cold water pipe resistance value, hot water pipe resistance value, water heater resistance value, and check valve resistance value, determine cold water pipe resistance elements, hot water pipe resistance elements, water heater resistance elements, and check valve resistance elements with equal resistance; Build a simulation model according to the relative positions of the cold water pipe, the hot water pipe, the water heater, the check valve, the water inlet, and the water outlet stored in advance and the cold water pipe resistance elements, the hot water pipe resistance elements, the water heater resistance elements, and the check valve resistance elements.

6. The device according to claim 5, characterized in that The acquisition module is specifically configured to: In the corresponding relationship between the cold water pipe length and the cold water pipe resistance stored in advance, query the cold water pipe resistance value corresponding to the cold water pipe length in the to-be-installed zero-cold-water system without a return pipe; In the corresponding relationship between the pre-stored length of the hot water pipe and the resistance of the hot water pipe, query the resistance value of the hot water pipe corresponding to the length of the hot water pipe in the to-be-installed zero-cold-water system without a return pipe; In the corresponding relationship between the pre-stored volume of the water heater and the resistance of the water heater, query the resistance value of the water heater corresponding to the volume of the water heater in the to-be-installed zero-cold-water system without a return pipe; In the corresponding relationship between the pre-stored one-way valve model and the resistance of the one-way valve, query the resistance value of the one-way valve corresponding to the one-way valve model in the to-be-installed zero-cold-water system without a return pipe.

7. The device according to claim 5, characterized in that, The output module is specifically configured to: For each total water flow rate among the total water flow rates, according to the total water flow rate input to the simulation model, output the water flow velocity of the one-way valve resistance element and the pressure drop value corresponding to the water flow velocity, and use the pressure drop value as the pressure drop value of the one-way valve corresponding to the total water flow rate.

8. The device according to claim 5, characterized in that The device further includes: An input module, configured to input a test total water flow rate; A second acquisition module, configured to acquire a first hot water pipe water flow rate of an actual model established based on the simulation model and a first overall pressure drop value between the water inlet and the water outlet; A third acquisition module, configured to acquire a second hot water pipe water flow rate of the simulation model and a second overall pressure drop value between the water inlet and the water outlet; A third processing module, configured to calculate a difference in water flow rate between the first hot water pipe water flow rate and the second hot water pipe water flow rate, and a difference in pressure drop between the first overall pressure drop value and the second overall pressure drop value; A fourth processing module, configured to determine that the simulation model meets a preset accuracy requirement if the absolute value of the ratio of the water flow rate difference to the second hot water pipe water flow rate is less than or equal to a preset first accuracy threshold, and the absolute value of the ratio of the pressure drop difference to the second overall pressure drop value is less than or equal to a preset second accuracy threshold.

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