A method for temperature and flow control in a water purifier and the water purifier itself.

Abstract

This application discloses a temperature and flow control method for a water purifier and a water purifier in general. The method includes: determining the set outlet water temperature and set outlet water flow rate of the target water purifier; acquiring the real-time outlet water flow rate of the target water purifier, executing a flow control strategy, and confirming the theoretical outlet water flow rate of the target water purifier; acquiring the real-time outlet water temperature of the target water purifier, executing a temperature control strategy based on the set outlet water temperature, real-time outlet water temperature, set outlet water flow rate, and theoretical outlet water flow rate, and adjusting the duty cycle of the heat pump and the cold pump of the target water purifier based on the temperature control strategy to drive the target water purifier; the flow control strategy and the temperature control strategy operate synchronously. By monitoring the total water flow rate with only a single total outlet water flow meter, and automatically adjusting the duty cycles of the cold pump and heat pump according to the target outlet water temperature, it is not necessary to monitor the flow rate of each cold and hot water stream, and it can also achieve the purpose of automatically adjusting the mixing ratio of cold and hot water to achieve the set water temperature and flow rate.

Description

Technical Field

[0001] This application relates to the field of water purifiers, specifically to a temperature and flow control method for a water purifier and a water purifier. Background Technology

[0002] In existing water purifiers with heating tanks, the hot water temperature is generally only selectable in two ways: one is the temperature of the heating tank (usually boiling water), and the other is the temperature of the water mixed with tap water from the heating tank, typically between 50 and 60°C. However, due to the inconsistency of the temperature and flow rate of the externally supplied tap water, the water temperature after mixing with the hot water is not constant, resulting in a large temperature difference between different situations. The flow rate of the mixed water is also inconsistent, leading to inconsistent water output, which affects the user experience and prevents users from setting arbitrary temperatures.

[0003] To solve the above problems, in a disclosed prior art, flow detection devices are respectively installed in the cold water pipeline and the hot water pipeline. The flow detection devices detect the flow rate of hot and cold water, and in conjunction with the actual outlet water temperature detected by the temperature sensor and the user's set outlet water temperature, the water pumping device installed in the hot water pipeline and the cold water pipeline is adjusted to achieve a constant flow rate and ensure that the actual outlet water temperature reaches the set outlet water temperature.

[0004] The above method requires the simultaneous installation of flow detection devices in both the cold and hot water pipes to monitor the flow rates of both water. For example, using two flow meters to detect and simultaneously transmit flow data to the control module results in high overall costs and resource consumption of the control module. Furthermore, flow loss occurs when the cold and hot water are mixed, causing the final total outflow to be less than the theoretical sum of the two. Different error values ​​will occur under different set outflow rates and set outflow temperatures. To solve the error value problem, a total flow detection device needs to be added to the mixing outlet, further increasing the overall cost of the machine and the resource consumption of the control module, such as the control chip.

[0005] In another existing technology, the operating power of the hot water pump is determined by setting the outlet water temperature, and then the outlet water flow rate of the hot water pump is determined by the operating power of the hot water pump. Combined with the set outlet water flow rate, the outlet water flow rate of the cold water pump is determined, and then the operating power of the cold water pump is determined. By controlling the operating power of the hot water pump and the cold water pump, the total outlet water flow rate of the flow control device is controlled, thereby achieving the ratio adjustment of hot and cold water and mixing hot water of different temperatures.

[0006] In the aforementioned solution, when the cold water pump and hot water pump operate simultaneously, they influence each other, leading to errors in flow control and affecting the actual water flow rate. When the rated power of the two pumps is different, the pump with the higher actual water flow rate will create back pressure on the pump with the lower actual water flow rate. To reduce back pressure, the adjustment ratio range of the hot water pump and cold water pump is typically limited to make the data in the adjustment process more linear and ensure more accurate temperature control. However, this limitation on the adjustment ratio means that when a higher or lower temperature of hot water is required, the hot water pump and cold water pump cannot adjust further, resulting in a discrepancy between the final actual water temperature and the set water temperature, thus affecting the user experience.

[0007] Therefore, there is an urgent need for a solution that can reduce the use of flow detection devices and the overall resource consumption of the control module, while not limiting the adjustment ratio of hot and cold water pumps. Summary of the Invention

[0008] To address the aforementioned issues, this application proposes a temperature and flow control method for a water purifier and a water purifier in general. This method monitors the total water flow rate only using a total outlet flow meter, and automatically adjusts the duty cycle of the cold pump and heat pump based on the set outlet water temperature. This reduces resource consumption while not limiting the adjustment ratio of hot and cold water mixing. The method specifically includes:

[0009] Based on user needs, the set outlet water temperature and set outlet water flow rate of the target water purifier are determined; the real-time outlet water flow rate of the target water purifier is obtained, and flow control is performed based on the set outlet water flow rate and the real-time outlet water flow rate to confirm the theoretical outlet water flow rate of the target water purifier; the real-time outlet water temperature of the target water purifier is obtained, and temperature control is performed based on the set outlet water temperature, the real-time outlet water temperature, the set outlet water flow rate, and the theoretical outlet water flow rate; the heat pump duty cycle and cold pump duty cycle of the target water purifier are correlated and adjusted based on the temperature control to drive the target water purifier; the flow control and the temperature control operate synchronously.

[0010] In one example, the step of associating and adjusting the heat pump duty cycle and cold pump duty cycle of the target water purifier based on temperature control specifically includes: determining the heat pump duty cycle of the target water purifier based on the set outlet water temperature and the real-time outlet water temperature; and synchronously adjusting the cold pump duty cycle of the target water purifier according to the set outlet water flow rate or the theoretical outlet water flow rate based on the heat pump duty cycle.

[0011] In one example, the step of associating and adjusting the heat pump duty cycle and cold pump duty cycle of the target water purifier based on temperature control specifically includes: determining the cold pump duty cycle of the target water purifier based on the set outlet water temperature and the real-time outlet water temperature; and synchronously adjusting the heat pump duty cycle of the target water purifier according to the set outlet water flow rate or the theoretical outlet water flow rate based on the cold pump duty cycle.

[0012] In one example, the temperature control first adjusts the heat pump duty cycle and the cold pump duty cycle based on the set water flow rate until the theoretical water flow rate of the target water purifier is determined.

[0013] In one example, determining the theoretical water flow rate of the target water purifier based on the set water flow rate and the real-time water flow rate specifically includes: determining the water volume difference of the target water purifier using the real-time water flow rate and the set water flow rate; inputting the water volume difference into the flow loop model to confirm the flow control of the water purifier and obtain the theoretical water flow rate of the target water purifier.

[0014] In one example, in the flow loop model, the cold pump duty cycle and / or heat pump duty cycle of the water purifier are adjusted by the water volume difference until the real-time water flow rate reaches the set water flow rate.

[0015] In one example, before performing temperature control, the method includes: determining the temperature difference of the target water purifier using the set outlet water temperature and the real-time outlet water temperature; inputting the temperature difference into the duty cycle model to confirm the temperature control of the target water purifier.

[0016] In one example, in the duty cycle loop model, the cold pump duty cycle and heat pump duty cycle of the water purifier are adjusted by the temperature difference until the real-time outlet water temperature reaches the set outlet water temperature.

[0017] In one example, the speed ratio between the first adjustment speed of the flow control and the second adjustment speed of the temperature control is higher than a preset threshold.

[0018] This application also provides a water purifier, comprising: a mixing unit, the mixing unit including a cold water pump, a hot water pump, and a mixing pipeline; a detection unit, the detection unit including a temperature sensor and a flow meter, both the temperature sensor and the flow meter being located at the outlet end of the mixing unit; a control unit, the control unit being used to receive information from the detection unit, receive user instructions, and control the operating status of the mixing unit; and a purification unit, the purification unit being connected to the inlet end of the mixing unit, for purifying raw water.

[0019] The method proposed in this application can bring the following beneficial effects:

[0020] 1. The total water flow is monitored by a single main water flow meter. The duty cycle of the cold pump and the heat pump is automatically adjusted according to the set outlet water temperature. It is not necessary to monitor the flow rate of each cold and hot water channel. This reduces the need for a flow meter and can still achieve the purpose of automatically adjusting the mixing ratio of cold and hot water to achieve the set water temperature and flow rate. At the same time, the solution in this application is not affected by the back pressure when the water is mixed and there is no need to limit the mixing ratio of cold and hot water. It can meet different set outlet water temperatures and improve the user experience.

[0021] 2. Based on temperature control, the duty cycle of the cold pump or the duty cycle of the heat pump can be calculated separately, and then another duty cycle can be calculated based on the existing duty cycle, so that the real-time water flow and temperature of the water purifier are close to or equal to the set value, thus improving the control accuracy.

[0022] 3. When adjusting the outlet flow rate and outlet temperature, the flow control is faster when the flow control and temperature control are running synchronously. The duty cycle is adjusted first based on the set outlet flow rate until the outer loop completes one cycle to obtain the theoretical outlet flow rate. Then, the theoretical outlet flow rate is used as the adjustment standard for the temperature control duty cycle, which improves the response speed and accuracy.

[0023] 4. When performing flow control, the duty cycle of a single pump can be adjusted individually to make the real-time outflow equal to the set outflow, thus improving the accuracy of the adjustment.

[0024] 5. When adjusting the temperature, the duty cycle of the cold pump and the heat pump is adjusted to ensure that the overall real-time water flow rate of the water purifier remains unchanged, thus improving the accuracy of the adjustment.

[0025] 6. By setting the speed ratio between flow control and temperature control, it is possible to prevent the flow rate adjustment from being too slow and affecting the duty cycle adjustment of the cold pump and heat pump. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0027] Figure 1 This is a schematic flowchart of a temperature and flow control method for a water purifier according to an embodiment of this application;

[0028] Figure 2 This is a modular schematic diagram of a water purifier according to an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of an inner and outer loop control strategy for a water purifier in an embodiment of this application;

[0030] Figure 4This is a data diagram related to a water purifier temperature and flow control method in an embodiment of this application. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0033] Figure 1 This is a schematic flowchart illustrating a temperature and flow control method for a water purifier, provided for one or more embodiments of this specification. This method is applied to the water purifier disclosed in this application, such as... Figure 2 As shown, the system includes: a mixing unit 201, which includes a cold water pump, a hot water pump, and a mixing pipeline; a detection unit 202, which includes a temperature sensor and a flow meter, both located at the outlet of the mixing unit; a control unit 203, which receives information from the detection unit, receives user commands, and controls the operation of the mixing unit; and a water purification unit 204, which is connected to the inlet of the mixing unit and is used to purify the raw water.

[0034] This process can be executed by the water purifier's control unit, and certain input parameters or intermediate results in the process can be manually adjusted to help improve accuracy.

[0035] The analysis method involved in the embodiments of this application can be implemented by a terminal device or a server, and this application does not impose any special limitations on it. For ease of understanding and description, the following embodiments are all described in detail using a server as an example.

[0036] It should be noted that the server can be a single device or a system composed of multiple devices, i.e., a distributed server. This application does not make any specific limitations in this regard.

[0037] like Figure 1 As shown in the figure, this application provides a temperature and flow control method for a water purifier, including:

[0038] S101: Based on user needs, determine the set outlet water temperature and set outlet water flow rate of the target water purifier.

[0039] First, based on the user's setting instructions, the set outlet water temperature and set outlet water flow rate of the target water purifier given by the user are determined. This setting instruction can be manually canceled or changed by the user. When no other instructions from the user are received, the set outlet water temperature and set outlet water flow rate contained in the setting instruction are used as the reference data. In the subsequent adjustment process, the real-time outlet water flow rate and real-time outlet water temperature of the water purifier are made close to or equal to the above reference data.

[0040] S102: Obtain the real-time water flow rate of the target water purifier, perform flow control based on the set water flow rate and the real-time water flow rate, and confirm the theoretical water flow rate of the target water purifier.

[0041] In this step, the current real-time water flow rate of the target water purifier is obtained through a flow monitoring device. In one embodiment of this example, the current real-time water flow rate is detected by a total flow meter installed at the outlet of the mixing pipe and transmitted to the value control module. The control module performs flow control by comparing the real-time water flow rate with the set water flow rate. Specifically, when the real-time water flow rate is greater than the set water flow rate, the output of the cold water pump or hot water pump is reduced, and vice versa. That is, in this embodiment, the outer loop flow control is specifically performed by comparing the set water flow rate and the real-time water flow rate given by the user. The purpose of the flow control is to make the real-time water flow rate of the water purifier close to or equal to the set water flow rate.

[0042] After the above flow control is completed, the theoretical water flow rate of the target water purifier can be obtained for subsequent adjustment. It should be noted that the theoretical water flow rate here is the sum of the cold water pump flow rate and the hot water pump flow rate after the flow control is completed. The specific method of obtaining it is to obtain the cold water pump flow rate and the hot water pump flow rate that are continuously adjusted and finally stabilized during the flow control process, and then sum the cold water pump flow rate and the hot water pump flow rate. Since there will be flow loss when cold water and hot water meet, the final mixed water flow rate will be relatively reduced. Therefore, the theoretical water flow rate obtained by calculation will be slightly higher than the set water flow rate.

[0043] The flow control process obtains the theoretical outflow rate to solve the flow loss problem that occurs during the mixing of water. This reduces the back pressure effect of the pump with a high real-time outflow velocity on the pump with a low real-time outflow velocity, eliminates the flow velocity calculation error caused by the mixing of two water streams, and eliminates the need to limit the adjustment ratio of the cold water pump or hot water pump during the adjustment process. This allows the pump to work at any duty cycle, meet the needs of different set outflow temperatures, and improve the user experience.

[0044] S103: Obtain the real-time outlet water temperature of the target water purifier, perform temperature control based on the set outlet water temperature, the real-time outlet water temperature, the set outlet water flow rate and the theoretical outlet water flow rate, and adjust the heat pump duty cycle and cold pump duty cycle of the target water purifier based on the temperature control to drive the target water purifier, and the temperature control and flow control operate synchronously.

[0045] After obtaining the theoretical outlet flow rate through the outer loop flow control, the real-time outlet water temperature of the target water purifier is acquired. Then, based on the user-provided set outlet water temperature, set outlet flow rate, and theoretical outlet flow rate, the inner loop temperature control of the target water purifier is executed. During the temperature control process, the heat pump duty cycle and cold pump duty cycle of the target water purifier are initially set based on the set outlet water temperature and set outlet flow rate. Then, by comparing the real-time outlet water temperature with the set outlet water temperature, the heat pump duty cycle and cold pump duty cycle are further adjusted. Specifically, when the real-time outlet water temperature is higher than the set outlet water temperature, the heat pump duty cycle is decreased or the cold pump duty cycle is increased; when the real-time outlet water temperature is lower than the set outlet water temperature, the cold pump duty cycle is increased or the heat pump duty cycle is decreased, so that the real-time outlet water temperature is close to or equal to the set outlet water temperature.

[0046] In the above temperature control process, after the real-time outlet water temperature stabilizes, the specific values ​​of the cold pump duty cycle and the hot pump duty cycle are determined so that they simultaneously satisfy the requirements of the cold water pump outlet flow rate and the hot water pump flow rate and the set outlet flow rate or theoretical outlet flow rate, so as to achieve the effect of constant temperature and constant flow water output of the water purifier.

[0047] In this embodiment, as Figure 3 As shown, the outer loop flow control in step S102 and the inner loop temperature control in step S103 operate synchronously. While the outer loop flow control is calculating, the duty cycle of the cold pump and the heat pump is adjusted simultaneously to make the real-time water flow close to or equal to the set water flow. The overall goal is to make the real-time water flow and real-time water temperature of the water purifier close to or equal to the set values. Under the control method improved in this embodiment, the temperature control and flow control are a long-term continuous operation process. When the user changes the set water flow and set water temperature at any time, the adjustment can be made quickly, improving the user experience.

[0048] The pump's duty cycle refers to the input voltage duty cycle. For example, for a DC pump with a rated voltage of 24V and a rated flow rate of 1.2L / min, when the input voltage duty cycle is 50%, the actual average voltage drops to 12V. Due to the reduced supply voltage, the pump speed decreases, and the pump's output flow rate also decreases, attenuating to approximately 0.6L / min. Although the pump's duty cycle and actual flow rate are not perfectly linear, they are generally close to a certain linear relationship. Ignoring linearity errors, a simple formula can be used to derive the relationship between pump flow rate and duty cycle, as follows: Measuring the flow rate of a cold water pump operating alone and its duty cycle shows that the cold water pump flow rate equals the product of the cold water pump coefficient and the cold water pump duty cycle. Measuring the flow rate of a hot water pump operating alone and its duty cycle shows that the hot water pump flow rate equals the product of the hot water pump coefficient and the hot water pump duty cycle.

[0049] In one specific embodiment of this example, when adjusting the heat pump duty cycle and cold pump duty cycle of the target water purifier based on temperature control, the heat pump duty cycle of the target water purifier can be determined first based on the set outlet water temperature and the real-time outlet water temperature, and then the cold pump duty cycle of the target water purifier can be adjusted synchronously based on the heat pump duty cycle and the set outlet water flow rate or the theoretical outlet water flow rate. The cold pump duty cycle of the target water purifier can be determined based on the set outlet water temperature and the real-time outlet water temperature. Then, based on the cold pump duty cycle, the heat pump duty cycle of the target water purifier can be adjusted synchronously according to the set outlet water flow rate or the theoretical outlet water flow rate. Since this embodiment strongly correlates the heat pump duty cycle and the cold pump duty cycle by setting the outlet water flow rate or calculating the theoretical outlet water flow rate, the control module only needs to determine one of the heat pump duty cycle or the cold pump duty cycle to accurately adjust the cold water pump and the hot water pump at the same time, so that the real-time outlet water temperature is close to or equal to the set outlet water temperature. At the same time, there is no need to install flow meters to detect the cold water flow rate and hot water flow rate after the cold water pump and the hot water pump, which reduces the hardware setup cost and the resource occupation of the control module. That is, only one total outlet water flow meter needs to be set to monitor the total water flow rate, which can also achieve the purpose of automatically adjusting the mixing ratio of cold water and hot water to achieve the set water temperature and water volume.

[0050] Furthermore, when adjusting the temperature control in the inner loop, the user-defined set water output is first obtained. Since temperature control and flow control are performed simultaneously, and the adjustment speed of temperature control is generally set relatively fast, the duty cycle of the chiller and heat pump is first adjusted based on the set water output flow rate to complete the initial temperature control. This process continues until the flow control in the outer loop completes one cycle and the theoretical water output flow rate is obtained. Then, the theoretical water output flow rate is used instead of the set water output flow rate as the adjustment standard for the duty cycle of the inner loop.

[0051] In one example, when determining the theoretical water flow rate of the target water purifier based on the set water flow rate and the real-time water flow rate, it is necessary to determine the water volume difference between the real-time water flow rate and the set water flow rate. Specifically, this difference can be calculated by measuring the difference between the real-time water volume and the set water flow rate. This water volume difference is then input into the flow loop model to obtain the theoretical water flow rate of the target water purifier in the current flow control cycle. Furthermore, during flow regulation, the duty cycle of a single pump can be adjusted individually to achieve flow adjustment. In this case, the duty cycle of the cold pump and / or the heat pump of the water purifier can be adjusted in the flow loop model using the water volume difference until the real-time water flow rate reaches the set water flow rate. The above PID control adjustment and the PID model utilize discrete PID formulas to calculate and obtain the theoretical water flow rate, thereby adjusting the real-time water flow rate to ultimately maintain consistency with the set water flow rate.

[0052] In one embodiment, before performing temperature control based on the set outlet water temperature, real-time outlet water temperature, set outlet water flow rate, and theoretical outlet water flow rate, it is also necessary to formulate temperature control based on the set outlet water temperature and real-time outlet water temperature. Specifically, it is necessary to determine the temperature difference of the target water purifier by setting the outlet water temperature and real-time outlet water temperature, and then input the temperature difference into the duty cycle loop model to confirm the temperature control of the target water purifier.

[0053] Furthermore, in the duty cycle loop model, after setting temperature control based on the temperature difference, it is necessary to keep the flow rate constant. At this time, it is necessary to adjust the duty cycles of both the chiller and the heat pump simultaneously. Therefore, it is necessary to adjust the duty cycles of the chiller and heat pump of the water purifier based on the aforementioned temperature difference until the real-time outlet water temperature reaches the set outlet water temperature.

[0054] In one embodiment, flow control is relatively slower than temperature control. Specifically, the speed ratio between the first adjustment speed of flow control and the second adjustment speed of temperature control is higher than a preset threshold. The purpose of setting this threshold is to prevent the outer loop adjustment from affecting the inner loop duty cycle adjustment, which would lead to large fluctuations and instability in the real-time outlet water temperature due to the excessively fast adjustment frequency of the inner loop. Specifically, the preset threshold can reach 20 to 50 times. Within this range, the inner loop temperature control process is relatively stable. When the speed ratio is lower than 20, it is easy to affect the inner loop. When it is higher than 50, the temperature control frequency of the inner loop is too low compared to the outer loop, resulting in inaccurate temperature adjustment. There will be a large error between the real-time outlet water temperature and the set outlet water temperature, affecting the user experience. In other embodiments, in addition to the PID control method mentioned above, bang-bang control or pure proportional control can also be used to calculate and control the theoretical outlet water flow.

[0055] In this embodiment, as Figure 3 As shown, the control process of the outer loop flow control is as follows: obtain the user's set outlet flow rate and the target water purifier's current real-time outlet flow rate, determine the theoretical outlet flow rate based on the set outlet flow rate and the real-time outlet flow rate, and input the theoretical outlet flow rate into the inner loop temperature control; the control process of the inner loop temperature control is as follows: obtain the user's set outlet temperature and the target water purifier's current real-time outlet temperature, determine the duty cycle of one of the pumps based on the set outlet temperature and the real-time outlet temperature, then determine the first output flow rate of the first pump based on the duty cycle, then determine the second output flow rate of the second pump based on the theoretical outlet flow rate and the first output flow rate, and finally determine the duty cycle of the second pump based on the second output flow rate.

[0056] Specifically, taking the first pump as a heat pump and the second pump as a cold pump as an example: After determining the duty cycle of the heat pump, the flow rate of the hot water pump is determined using the following formula:

[0057] S 热 =A 热 *PWM 热

[0058] Among them, S 热 A is the output flow rate of the hot water pump. 热 For the duty cycle coefficient of the hot water pump, PWM 热 This represents the heat pump duty cycle. Then, based on the theoretical outlet water flow rate and the heat pump outlet water flow rate, the chilled water pump flow rate is determined using the following formula:

[0059] S 理论 =S 热 *S 冷

[0060] Among them, S 理论 S is the theoretical outflow rate. 冷 Let be the output flow rate of the chilled water pump. Then, based on the output flow rate and the chilled water pump duty cycle coefficient, determine the chilled water pump's duty cycle using the following formula:

[0061] S 冷 =A 冷 *PWM 冷

[0062] Among them, A 冷 For the duty cycle coefficient of the cold pump, PWM 冷 This refers to the duty cycle of the cold pump.

[0063] In the specific implementation process of this embodiment, the flow rate and temperature of the water purification system equipped with the corresponding structure and pipeline are detected, and the relevant measurement data are as follows: Figure 4As shown, taking cold water at 25℃, hot tank insulation temperature at 80℃, cold pump maximum flow rate at 1200ml / min, and heat pump maximum flow rate at 2000ml / min as an example, the water flow rate is set to 1500ml / min and the water temperature is set to 60℃. Although flow control and temperature control are performed simultaneously, the flow control is slower than the temperature control, so it can be considered that temperature control is performed first.

[0064] Temperature control process: The actual temperature is detected. When the actual temperature is greater than or less than the set outlet water temperature of 60℃, the heat pump duty cycle is decreased or increased according to the PID control until the real-time outlet water temperature T is reached. 实际 Approximately equal to or equal to the set outlet water temperature T 设定 (Error less than ±1℃), and based on the theoretical outflow rate S 理论 (i.e., the total calculated flow rate in the table data) The duty cycle of the cold pump is calculated. Since the inner and outer loops operate synchronously, the duty cycle of the inner loop is first adjusted with a set outflow rate of 1500 ml / min. The resulting duty cycle of the heat pump is 47.73%, and the duty cycle of the cold pump is 45.45%. That is, the heat pump flow rate is 955 ml / min and the cold pump flow rate is 545 ml / min. At the same time, the inner loop continues to circulate to keep the actual temperature stable at around 60℃.

[0065] Flow control process: When the real-time outlet water flow rate is greater than or less than the set outlet water flow rate of 1500 ml / min, the duty cycle of the chiller and / or heat pump is reduced or increased according to the PID control until the real-time outlet water flow rate S is reached. 实际 Approximately equal to or equal to the set output flow rate S 设定 (Error less than ±10 ml / min). For example, if the total actual output flow rate after PID adjustment is 1505 ml / min, the theoretical outlet flow rate S can be calculated using the PID discrete formula. 理论 The flow rate is 1580 ml / min (this value is due to flow loss when mixing water from the cold pump and the heat pump; the sum of the output flow rates of the cold and heat pumps will be greater than the total actual flow rate). The theoretical outlet flow rate S is input into the inner loop. 理论 The inner loop readjusts the duty cycle of the cold pump and the heat pump based on this value to stabilize the temperature at 60℃, resulting in a heat pump duty cycle of 52% and a cold pump duty cycle of 50%. The inner and outer loops continuously cycle and control each other, with the inner loop adjusting faster than the outer loop, achieving the effect of stabilizing temperature and flow while reducing the influence of the outer loop on the inner loop adjustment.

[0066] Re-running the control method of this embodiment, taking the cold water temperature of 25℃, the hot tank insulation temperature of 80℃, the maximum flow rate of the cold pump of 1200ml / min, and the maximum flow rate of the heat pump of 2000ml / min as an example, the set water flow rate is 1500ml / min, the set temperature is 50 degrees, and the real-time water flow rate after outer loop adjustment is 1510ml / min. During the process of adjusting the real-time water flow rate to the set water flow rate, due to the synchronous adjustment of the inner and outer loops and the existence of system errors, it is difficult to adjust it to be exactly equal to the set water flow rate. In actual operation, an error within 0-10ml / min is allowed. The existence of this error has little impact on the subsequent temperature control and flow control cycle process.

[0067] Specifically, the temperature control process involves detecting the actual temperature. When the actual temperature is greater than or less than the set outlet water temperature by 50°C, the heat pump duty cycle is adjusted according to the PID controller until the real-time outlet water temperature T is reached. 实际 Approximately equal to or equal to the set outlet water temperature T 设定 Meanwhile, based on the theoretical outflow rate S 理论 The duty cycle of the chiller was calculated. Since the inner and outer loops operate synchronously, the duty cycle of the inner loop was first adjusted with a set outflow rate of 1500 ml / min. The resulting duty cycle of the heat pump was 34.09%, and the duty cycle of the chiller was calculated to be 68.18%, which means the heat pump flow rate was 682 ml / min and the chiller flow rate was 818 ml / min. At the same time, the inner loop was continuously circulated to keep the actual temperature stable at around 50℃.

[0068] Flow control process: When the real-time outlet water flow rate is greater than or less than the set outlet water flow rate of 1500 ml / min, the duty cycle of the chiller and / or heat pump is reduced or increased according to the PID control until the real-time outlet water flow rate S is reached. 实际 Approximately equal to or equal to the set output flow rate S 设定 For example, if the total actual output flow rate after PID regulation is 1510 ml / min, the theoretical outlet flow rate S can be calculated using the PID discrete formula. 理论 The theoretical outflow rate S is 1600 ml / min. 理论 The inner ring then readjusts the duty cycles of the cold pump and the heat pump based on this value to stabilize the temperature at 50°C, resulting in a heat pump duty cycle of 40% and a cold pump duty cycle of 75%.

[0069] This invention primarily addresses the user's desire for a high flow rate of hot water. Therefore, the water purifier incorporates a built-in heating tank that heats the water to 80°C. When hot water is needed, if the water temperature is above 80°C, hot water can be dispensed directly. If the water temperature is below 80°C, cold and hot water can be mixed. A single total flow meter monitors the total water flow rate and automatically adjusts the duty cycle of the cold and hot pumps based on the set outlet temperature. This eliminates the need to monitor the flow rate of each individual cold and hot water stream, reducing the need for a separate flow meter while still achieving the desired flow rate and temperature.

[0070] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device and medium embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the description of the method embodiments.

[0071] The devices and media provided in this application are one-to-one with the methods. Therefore, the devices and media also have similar beneficial technical effects as their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A temperature flow control method for a water purifier, characterized by, The method comprises the following steps: determining the set outlet water temperature and the set outlet water flow rate of a target water purifier based on user demand; obtaining the real-time outlet water flow rate of the target water purifier, performing flow control based on the set outlet water flow rate and the real-time outlet water flow rate, and confirming the theoretical outlet water flow rate of the target water purifier; obtaining the real-time outlet water temperature of the target water purifier, performing temperature control based on the set outlet water temperature, the real-time outlet water temperature, the set outlet water flow rate, and the theoretical outlet water flow rate, correlating and adjusting the duty cycle of the heat pump and the duty cycle of the cold pump of the target water purifier based on the temperature control, and driving the target water purifier; the flow control and the temperature control are synchronously operated; the correlating and adjusting of the duty cycle of the heat pump and the duty cycle of the cold pump of the target water purifier based on the temperature control specifically comprises: determining the duty cycle of the heat pump of the target water purifier based on the set outlet water temperature and the real-time outlet water temperature; synchronously adjusting the duty cycle of the cold pump of the target water purifier according to the set outlet water flow rate or the theoretical outlet water flow rate based on the duty cycle of the heat pump; or determining the duty cycle of the cold pump of the target water purifier based on the set outlet water temperature and the real-time outlet water temperature; synchronously adjusting the duty cycle of the heat pump of the target water purifier according to the set outlet water flow rate or the theoretical outlet water flow rate based on the duty cycle of the cold pump.

2. The method of claim 1, wherein, In the temperature control, the duty cycle of the heat pump and the duty cycle of the cold pump are adjusted based on the set outlet water flow rate first until the theoretical outlet water flow rate of the target water purifier is determined.

3. The method of claim 1, wherein, The confirming of the theoretical outlet water flow rate of the target water purifier based on the set outlet water flow rate and the real-time outlet water flow rate specifically comprises: determining the water quantity difference of the target water purifier through the real-time outlet water flow rate and the set outlet water flow rate; inputting the water quantity difference into a flow loop model to confirm the flow control of the water purifier and obtain the theoretical outlet water flow rate of the target water purifier.

4. The method of claim 3, wherein, In the flow loop model, the duty cycle of the cold pump and / or the duty cycle of the heat pump of the water purifier are adjusted through the water quantity difference until the real-time outlet water flow rate reaches the set outlet water flow rate.

5. The method of claim 1, wherein, Before the temperature control is performed, the method comprises: determining the temperature difference of the target water purifier through the set outlet water temperature and the real-time outlet water temperature; inputting the temperature difference into a duty cycle loop model to confirm the temperature control of the target water purifier.

6. The method of claim 5, wherein, In the duty cycle loop model, the duty cycle of the cold pump and the duty cycle of the heat pump of the water purifier are adjusted through the temperature difference until the real-time outlet water temperature reaches the set outlet water temperature.

7. The method of claim 1, wherein, The speed multiple between the first adjustment speed of the flow control and the second adjustment speed of the temperature control is higher than a preset threshold.

8. A water purifier characterized by comprising: The method comprises the following steps: a water mixing unit, which comprises a cold water pump, a hot water pump, and a water mixing pipeline; a detection unit, which comprises a temperature sensor and an outlet water flow meter, and the temperature sensor and the outlet water flow meter are arranged at the outlet end of the water mixing unit; a control unit, which is used for receiving information of the detection unit, receiving instructions of a user, and controlling the operating state of the water mixing unit; the control unit performs the temperature and flow control method for a water purifier according to any one of claims 1-7. A water purification unit is in communication with the water inlet end of the water mixing unit for purifying raw water.

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