A method for water shortage alarm in drinking water equipment

Abstract

A method for water shortage alarm in drinking water equipment includes a flow meter, a zero-pressure valve, a water pump, and an instant heating component. The initial flow rate for the system's initial operating mode is calculated based on the power of the water pump and the instant heating component, as well as the accuracy of the flow meter. Simultaneously, the flow meter detects dynamic changes in the flow rate. When the flow rate change reaches a trigger value, a water shortage alarm is initiated. An anti-false alarm program is added, increasing the water pump power to provide feedback on whether the flow rate recovers, and incorporating this feedback into the system's judgment until a true water shortage is confirmed. Heating is stopped before actual steam is emitted. This achieves highly sensitive water shortage detection, while the anti-false alarm program reduces the possibility of misjudgment, maximizing system and user protection while ensuring stable and normal system operation.

Description

Technical Field

[0001] This invention relates to the field of drinking water equipment technology, and more particularly to a method for alarming water shortage in drinking water equipment. Background Technology

[0002] With the improvement of living standards and the increasing level of industrialization, various drinking water equipment is being used more and more widely and popularly, leading to continuous technological improvements in drinking water equipment. As technology continues to upgrade, people's demands for drinking water equipment are also increasing, with expectations for clean and hygienic drinking water, adjustable water temperature heating, and quick and uninterrupted access.

[0003] Currently, there are water dispensers on the market that incorporate instant heating technology. These devices use high-powered instant heating components to heat purified, drinkable water to a set temperature, providing instant drinking water at any temperature to meet various user needs, such as making formula, beverages, tea, and coffee. However, existing instant water dispensers still contain a purified water tank, which is susceptible to secondary contamination upon contact with air. This secondary contamination issue has garnered attention, leading the industry to gradually replace tankless instant water dispensers with tankless heating technology. Tankless heating technology directly draws, heats, and dispenses water. The biggest problem currently is water shortage detection. With direct heating, an alarm must immediately sound and stop the device if water is low, otherwise, high-temperature steam will be emitted, posing a significant safety hazard to users. Currently, water shortage detection is achieved through high-temperature alarms, which suffer from an inherent system delay. This results in insufficient sensitivity; often, high-temperature steam has already been generated before the alarm sounds and the device stops, still posing a considerable safety risk to users. Summary of the Invention

[0004] This invention addresses the above-mentioned technical problems by proposing a method for water shortage alarms in drinking water equipment. By selecting a suitable flow meter for the heating element and calculating the appropriate starting flow rate q1 based on the parameters of the flow meter and the heating element, precise flow variable control is used to trigger an alarm and interrupt the heating process before high-temperature steam is produced. This achieves highly sensitive water shortage detection, while incorporating a false alarm prevention program to reduce the possibility of misjudgment, maximizing the protection of the system and the user, and ensuring stable and normal system operation.

[0005] The present invention relates to a method for alarming water shortage in a drinking water device, wherein the drinking water device includes a flow meter, a zero-pressure valve, a water pump, and an instant heating component, wherein the water pump pumps water to supply the instant heating component, a zero-pressure valve is provided before the water pump, and a flow meter is provided at the inlet end of the zero-pressure valve, characterized in that the method for alarming water shortage includes the following steps:

[0006] S1: Start flow detection. Detect the flow rate when the system is first started. The preset initial heating flow rate of the system is q1. The system enters the working mode if the flow rate is greater than q1 by the flow meter.

[0007] S2: Dynamic water shortage detection. When the system is in normal working mode, if the flow meter detects a decrease in flow rate and the decrease reaches a preset value Δq = (1-k1q) related to the flow coefficient, the system is judged to be short of water.

[0008] S3: Anti-false judgment program. After S2 detects a decrease in flow and determines that the system is short of water, the anti-false judgment program will be triggered. The water pump voltage will be started up to the set value to determine whether the system flow rate meets the requirements under the set value.

[0009] S4: If the anti-false alarm procedure determines that the error is not a false alarm, the system will shut down the instant heating component; if the anti-false alarm procedure determines that the error is a false alarm, the system will maintain the current working mode and keep dynamic water shortage detection.

[0010] The flow rate decrease Δq = (1 - k1q), where k1 is the alarm flow rate decrease coefficient, and the formula for calculating k1 is as follows:

[0011] ηPt=CqρtΔT=Ck1qρtΔT3+kΔT2

[0012] Q – Heat, measured in joules (J);

[0013] η – Efficiency, which is 96% according to the parameters provided by the supplier;

[0014] C – Specific heat capacity; the specific heat capacity of water is 4.2 * 10⁻⁶. 3 J / (kg·℃) is equivalent to 4.2 J / (g·℃);

[0015] P – Power, measured in watts (W);

[0016] ρ—density; the density of water is 1 g / ml, 1 g / cm³. 3 ;

[0017] t — time, in seconds

[0018] q – flow rate, in ml / min

[0019] ΔT — Normal outlet water temperature difference, in degrees Celsius (°C)

[0020] ΔT2 — The temperature difference between the boiling point and the normal outlet water temperature, in degrees Celsius (°C).

[0021] ΔT3 — The temperature difference between the boiling point and the normal inlet water temperature, in degrees Celsius (°C).

[0022] k1 — Flow rate reduction coefficient

[0023] k – the heat capacity of the heating element and its interior, which is approximately 50 J / g in this case, as determined experimentally.

[0024] In step S1, entering the working mode means starting heating, and at the same time, the flow rate is detected by a flow meter.

[0025] In step S1, if the system flow rate is not detected to reach q1, the water pump voltage is increased, and the system flow rate is checked again to see if it reaches q1. If it does not reach q1, an alarm for water shortage is triggered.

[0026] The minimum flow rate q1 for system startup is determined by calculation, using the following formula:

[0027] Q = ηPt = CmΔT

[0028] ηPt=CqρtΔT

[0029]

[0030] Q – Heat, measured in joules (J);

[0031] η – Efficiency, 96% according to the parameters provided by the supplier;

[0032] C – Specific heat capacity; the specific heat capacity of water is 4.2 * 10⁻⁶. 3 J / (kg·℃) is equivalent to 4.2 J / (g·℃);

[0033] P – Power, measured in watts (W);

[0034] ρ—density; the density of water is 1 g / ml, 1 g / cm³. 3 ;

[0035] t — time, in seconds;

[0036] q – flow rate, in ml / min;

[0037] T2 – Outlet water temperature, in degrees Celsius (°C);

[0038] T1—Inlet water temperature, in degrees Celsius (°C);

[0039] m — mass, measured in grams.

[0040] In the anti-false judgment procedure of step S3, when the flow rate drops beyond the set value, the anti-false judgment procedure is performed. First, the water pump voltage is increased, the flow rate under high pressure is detected, and it is determined whether the flow rate has recovered. If the flow rate has not recovered, it is determined that there is a water shortage. If the flow rate has recovered, the current working mode is maintained.

[0041] This invention addresses the aforementioned water shortage alarm method that uses fixed flow rate detection. Instead, it employs a flow meter for real-time flow rate monitoring. Not only is a flow rate set to initiate the operating mode based on the specific parameters of the water pump and instantaneous heating component, but the flow meter also detects the flow rate drop Δq. Once the drop exceeds a set value, the system determines that the system is short of water and triggers a false alarm prevention procedure. The overall design concept is to achieve highly sensitive and false alarm-proof real-time flow rate detection by using the initial flow rate q1 and the dynamic change Δq, thus avoiding dangerous situations such as steam spray and improving equipment safety. Attached Figure Description

[0042] Figure 1 This is a system structure diagram of a water shortage alarm for a drinking water device according to the present invention;

[0043] Figure 2 This is a system flowchart of a water shortage alarm method for drinking water equipment according to the present invention;

[0044] Figure 3 This is a system flowchart illustrating the specific calculation process of a water shortage alarm method for drinking water equipment according to the present invention;

[0045] Among them: 10, flow meter; 20, zero-pressure valve; 30, water pump; 40, instant heating component. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0047] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0048] Please refer to the attached document. Figure 1This invention is a method for water shortage alarm in tankless instant hot water equipment. Please refer to Table 1, which shows the detection effect of existing conventional systems using a fixed flow meter under heating conditions. Using fixed flow meter detection, it can be seen that the water temperature significantly exceeds the boiling point before the water shortage alarm is triggered. In other words, the whole machine first exhibits steam emission before the water shortage alarm is triggered and the heating is stopped. However, in reality, a relatively dangerous steam emission phenomenon has already occurred, posing an operational safety hazard.

[0049] 1 26 31 507.6923 2 26 80 507.6923 3 25 84 507.6923 4 25 87 484.6154 5 25 88 484.6154 6 25 89 484.6154 7 25 90 461.5385 8 25 91 461.5385 9 25 92 438.4615 10 25 91 438.4615 11 25 92 438.4615 12 25 92 438.4615 13 25 93 438.4615 14 25 94 438.4615 15 25 94 415.3846 16 25 94 438.4615 17 25 95 415.3846 18 24 93 415.3846 19 24 96 415.3846 20 24 95 438.4615 21 24 95 415.3846 22 24 95 415.3846 23 24 95 438.4615 24 24 95 415.3846 25 24 95 415.3846 26 24 95 415.3846 27 24 95 415.3846 28 24 95 438.4615 29 24 95 438.4615 30 24 95 438.4615 31 24 97 300 32 28 102 253.8462 33 water shortage 161.5385 34 Stop 4! 161.5385 35 Stop 4! 161.5385

[0050] Table 1: Data Table for Fixed Flow Measurement

[0051] Please refer to the attached document. Figure 1 and attached Figure 2 This invention addresses the aforementioned water shortage alarm method that uses fixed flow rate detection. Instead, it employs a flow meter for real-time flow rate monitoring. Not only is a flow rate set to initiate the operating mode based on the specific parameters of the water pump and instantaneous heating component, but the flow meter also detects the flow rate drop Δq. Once the drop exceeds a set value, the system determines that the system is short of water and triggers a false alarm prevention procedure. The overall design concept is to achieve highly sensitive and false alarm-proof real-time flow rate detection by using the initial flow rate q1 and the dynamic change Δq, thus avoiding the dangerous situation of steam spray and improving equipment safety.

[0052] The present invention relates to a method for alarming water shortage in a drinking water device. The drinking water device includes a flow meter 10, a zero-pressure valve 20, a water pump 30, and an instant heating component 40. The water pump 30 pumps water to supply the instant heating component 40. A zero-pressure valve 20 is provided before the water pump 30. A flow meter 10 is provided at the inlet end of the zero-pressure valve 20, using a volumetric flow meter scheme. The flow meter 10 must be installed at the inlet end of the zero-pressure valve 20 to ensure that the resistance generated by the flow meter 10 does not affect the flow rate of the water pump 30. Then, the zero-pressure valve 20 is connected, and the outlet end of the zero-pressure valve 20 is connected to the water pump and the instant heating component.

[0053] The method for triggering a water shortage alarm is characterized by comprising the following steps:

[0054] S1: Start flow detection. Detect the flow rate when the system is first started. The preset initial heating flow rate of the system is q1. The system enters the working mode if the flow rate is greater than q1 by the flow meter.

[0055] The minimum flow rate q1 for system startup is determined by calculation, using the following formula:

[0056] Q = ηPt = CmΔT

[0057] ηPt=CqρtΔT

[0058]

[0059] Q – Heat, measured in joules (J);

[0060] η – Efficiency, 96% according to the parameters provided by the supplier;

[0061] C – Specific heat capacity; the specific heat capacity of water is 4.2 * 10⁻⁶. 3 J / (kg·℃) is equivalent to 4.2 J / (g·℃);

[0062] P – Power, measured in watts (W);

[0063] ρ—density; the density of water is 1 g / ml, 1 g / cm³. 3 ;

[0064] t — time, in seconds;

[0065] q – flow rate, in ml / min;

[0066] T2 – Outlet water temperature, in degrees Celsius (°C);

[0067] T1 – Inlet water temperature, in °C (degrees Celsius).

[0068] m — mass, measured in grams.

[0069] First, determine the power P of the heating element, the tolerance (typically +5%-10%), the specific heat capacity k of the heating element and the internal water, and the operating voltage range (assuming 220V±15%). Then, the power range of the heating element is...

[0070]

[0071] The minimum flow rate of the entire unit is calculated based on the lowest power and lowest inlet water temperature of 0℃.

[0072] Q = ηPt = CmΔT

[0073] ηPt=CqρtΔT

[0074]

[0075] Therefore, the optimal calculated flow rate for the water shortage alarm is 187 ml / min.

[0076] The specifications of flow meters are generally as follows: there is a corresponding relationship between frequency and flow rate. The following table shows the specifications of flow meters and the conversion data according to the specification sheet.

[0077]

[0078] The system detection frequency is an integer. The frequency of 187 ml / min is 8.1 Hz. The flow rate of 8 Hz is 184 ml / min, which is the value of the starting flow rate q1. The flow rate of 1 Hz is 23 ml / min.

[0079] The heating element assembly has a heat capacity of 50 J / g and an outlet water temperature of 95℃. Simultaneously, the flow rate is set at 400 ml / min, the inlet water temperature is 25℃, the outlet water temperature is 95℃, and the time calculation period is 1 second, with a temperature difference of 5℃ from boiling.

[0080] S2: Dynamic water shortage detection. When the system is in normal operating mode, if the flow meter detects a decrease in flow rate and the decrease reaches Δq = (1 - k1q) when the pump voltage remains constant, then the system is judged to be short of water. Theoretically, the system flow rate should not change when the pump voltage remains constant, so the only possible factor that could cause a change is water shortage.

[0081] S3: Anti-false judgment program. The above detection conditions are all based on water shortage detection under non-fixed conditions. However, the actual detection will also be affected by the accuracy of the flow meter. Therefore, an anti-false judgment program needs to be added to prevent the program from being too sensitive and stopping the machine from heating from time to time when there is no water shortage.

[0082] After S2 detects a decrease in flow and determines that the system is short of water, it will trigger the anti-false judgment program, start the water pump voltage to the set value, and determine whether the system flow meets the requirements under the set value.

[0083] S4: If the anti-false alarm procedure determines that the error is not a false alarm, the system will shut down the instant heating component; if the anti-false alarm procedure determines that the error is a false alarm, the system will maintain the current working mode and keep dynamic water shortage detection.

[0084] The flow rate decrease Δq = (1 - k1q), where k1 is the alarm flow rate decrease coefficient.

[0085] The formula for calculating k1 is as follows:

[0086] ηPt=CqρtΔT=Ck1qρtΔT3+kΔT2

[0087] Q – Heat, measured in joules (J);

[0088] η – Efficiency, which is 96% according to the parameters provided by the supplier;

[0089] C – Specific heat capacity; the specific heat capacity of water is 4.2 * 10⁻⁶. 3 J / (kg·℃) is equivalent to 4.2 J / (g·℃);

[0090] P – Power, measured in watts (W);

[0091] ρ—density; the density of water is 1 g / ml, 1 g / cm³. 3 ;

[0092] t — time, in seconds

[0093] q – flow rate, in ml / min

[0094] ΔT — Normal outlet water temperature difference, in degrees Celsius (°C)

[0095] ΔT2 — The temperature difference between the boiling point and the normal outlet water temperature, in degrees Celsius (°C).

[0096] ΔT3 — The temperature difference between the boiling point and the normal inlet water temperature, in degrees Celsius (°C).

[0097] k1 — Flow rate reduction coefficient

[0098] k – the heat capacity of the heating element and its interior, which is approximately 50 J / g in this case, as determined experimentally.

[0099] Assuming a flow rate of 400 ml / min, an inlet water temperature of 25℃, an outlet water temperature of 95℃, a temperature difference of 5℃ from boiling point, and a time calculation period of 1 second.

[0100]

[0101] The calculated value is k1 = 0.81

[0102] That is, the flow rate decrease is (1-0.81)*400=76ml / min. Considering the data error during control, it is necessary to accurately detect the flow rate of 76ml / min within ±1Hz. That is, the detection accuracy per 1Hz should be at least 76 / 2=38ml / min, and it is better to use an accuracy of less than 76 / 3=25ml / min.

[0103] In step S1, if the system flow rate is not detected to reach q1, the water pump voltage is increased, and the system flow rate is checked again to see if it reaches q1. If it does not reach q1, an alarm for water shortage is triggered.

[0104] In the anti-false judgment procedure of step S3, when the flow rate drops beyond the set value, the anti-false judgment procedure is performed. First, the water pump voltage is increased, the flow rate under high pressure is detected, and it is determined whether the flow rate has recovered. If the flow rate has not recovered, it is determined that there is a water shortage. If the flow rate has recovered, the current working mode is maintained.

[0105] Please refer to the attached document. Figure 3 Based on the above description and the specific calculations using the input data, the workflow can be summarized as follows:

[0106] 1. First, start the water pump to confirm that the water supply is normal and reaches 184ml / min;

[0107] 2. If the system water supply reaches 184ml / min, the heating function will be activated. If the system flow rate does not reach 184ml / min, the heating will be turned off and the water pump voltage will be increased. If the detected flow rate recovers, the heating function will be activated. If it does not recover, the heating and water pump supply will be stopped, and a water shortage alarm will be triggered.

[0108] 3. If the system enters normal heating mode, and the system flow rate is monitored, if the flow rate drops by more than 70 ml / min while the pump voltage remains constant, heating is turned off, the pump voltage is increased, and the flow rate under high pressure is monitored to determine if the system flow rate recovers. If the detected flow rate recovers, the heating function is resumed; otherwise, heating and water pump supply are stopped, and a water shortage alarm is triggered.

[0109] In summary: The system detects water shortage by maintaining a fixed flow rate when the system is static, and by detecting changes in flow rate when the system is dynamic. To prevent false alarms, the pump voltage is increased before the water shortage alarm is triggered, and the system determines whether the water shortage is detected by checking if the flow rate recovers. An additional false alarm prevention program is added to reconfirm the water shortage status.

[0110] 1 24 91 438.4615 2 24 93 438.4615 3 24 92 438.4615 4 24 94 438.4615 5 24 93 415.3846 6 24 94 415.3846 7 24 94 415.3846 8 24 95 415.3846 9 24 95 415.3846 10 24 95 415.3846 11 24 97 415.3846 12 24 96 392.3077 12.1 392.3077 12.2 369.2308 12.3 stop2 346.1538

[0111] Table 4: Improved Data Table for Alarm Using Dynamic Flow Detection

[0112] The table above shows the effect of using flow rate changes for alarm during heating. As you can see, the water shortage alarm is triggered even when the outlet water temperature has hardly changed, providing maximum protection for both the system and the user.

[0113] In summary, the beneficial effects of this invention are that it uses a flow meter to detect the flow rate in real time, eliminating the influence of the power of the water pump on the flow rate change, in order to determine whether there is a water shortage. At the same time, in order to avoid the occurrence of steam spraying due to the delay in the heating process, a flow rate drop Δq related to the flow coefficient is introduced into the system. By verifying the preset value, a highly sensitive water shortage detection is achieved. At the same time, the anti-false judgment function can also avoid false alarm triggering, which not only improves the safety of equipment use, but also ensures the normal functioning.

[0114] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present invention without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A method for alarming water shortage in a drinking water device, the drinking water device comprising a flow meter, a zero-pressure valve, a water pump, and an instant heating component, wherein the water pump pumps water to supply the instant heating component, a zero-pressure valve is provided before the water pump, and a flow meter is provided at the inlet end of the zero-pressure valve, characterized in that, The water shortage alarm method includes the following steps: S1: Start flow detection. Detect the flow rate when the system is first started. The preset initial heating flow rate of the system is q1. The system enters the working mode if the flow rate is greater than q1 by the flow meter. S2: Dynamic water shortage detection. When the system is in normal operating mode, and the pump voltage remains constant, the flow meter detects a decrease in flow rate, and the decrease reaches a preset value related to the flow coefficient. If so, the system is considered to be short of water; S3: Anti-false judgment program. After S2 detects a decrease in flow and determines that the system is short of water, the anti-false judgment program will be triggered. The water pump voltage will be started up to the set value to determine whether the system flow rate meets the requirements under the set value. S4: If the anti-false alarm procedure determines that the error is not a false alarm, the system shuts down the instant heating component; if the anti-false alarm procedure determines that the error is a false alarm, the system maintains the current operating mode and keeps dynamically detecting water shortage; the preset value for the flow rate decrease... ,in The alarm flow rate reduction coefficient, And the aforementioned The calculation formula is as follows: ； Q – Heat, measured in joules (J); —Efficiency, according to the parameters provided by the supplier, is 96%; C—Specific heat capacity. The specific heat capacity of water is 4.2*10³J / (kg·℃), which is 4.2J / (g·℃). P – Power, measured in watts (W); ρ—density, the density of water is 1g / ml, 1g / cm³; t — time, in seconds; q – flow rate, in ml / min; —The normal water temperature difference is expressed in degrees Celsius (°C). —The temperature difference between the boiling point and the normal outlet water temperature, expressed in degrees Celsius (°C). —The temperature difference between the boiling point and the normal inlet water temperature, expressed in degrees Celsius (°C). —This represents the flow rate reduction coefficient; K — the heat capacity of the heating element and its interior, which is 50 J / g in this case, as determined by experiments.

2. The method for alarming water shortage in drinking water equipment according to claim 1, characterized in that, In step S1, entering the working mode means starting heating, and at the same time, the flow rate is detected by a flow meter.

3. The method for alarming water shortage in drinking water equipment according to claim 1, characterized in that, In step S1, if the system flow rate is not detected to reach q1, the water pump voltage is increased, and the system flow rate is checked again to see if it reaches q1. If it does not reach q1, an alarm for water shortage is triggered. The minimum flow rate q1 for system startup is determined by calculation, using the following formula: ； Q – Heat, measured in joules (J); —Efficiency, 96% according to the parameters provided by the supplier; C—Specific heat capacity. The specific heat capacity of water is 4.2*10³J / (kg·℃), which is 4.2J / (g·℃). P – Power, measured in watts (W); ρ—density, the density of water is 1g / ml, 1g / cm³; t — time, in seconds; q – flow rate, in ml / min; —Outlet water temperature, in degrees Celsius (°C); —Inlet water temperature, in degrees Celsius (°C); m — mass, measured in grams.

4. The method for alarming water shortage in drinking water equipment according to claim 1, characterized in that, In the anti-false judgment procedure of step S3, when the flow rate drops beyond the set value, the anti-false judgment procedure is performed. First, the water pump voltage is increased, the flow rate under high pressure is detected, and it is determined whether the flow rate has recovered. If the flow rate has not recovered, it is determined that there is a water shortage. If the flow rate has recovered, the current working mode is maintained.

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