Method and system for intelligently adjusting and controlling water yield of hemodialysis equipment

Abstract

The invention discloses an intelligent water yield regulation control system for hemodialysis, which is characterized in that a variable frequency pump is triggered to dynamically modulate frequency by monitoring the liquid level of a balancer, the pressure and temperature of an RO (Reverse Osmosis) membrane and the water yield conductance in real time and combining with a liquid level change rate threshold value, so that the water yield can be regulated in a wide range of 2.0-4.5 T / H. Temperature compensation and a membrane life coefficient are introduced into the system to optimize the actual water yield, the demand is predicted through a moving average algorithm, and the adjustment frequency is reduced. After application, the water supply pressure is stabilized at 4 + / -0.2 bar, water is saved by more than 30%, and energy waste and backpressure risks caused by fixed water yield are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment of hemodialysis equipment, and more specifically, relates to a method and system for intelligently regulating and controlling the water production of hemodialysis equipment. Background Art

[0002] Currently, hemodialysis treatment requires the patient's blood to be removed from the body and exchanged with dialysate through a dialyzer to remove metabolic waste and excess water. Water production equipment is an indispensable component of hemodialysis treatment, and the stability and quality of its water output are directly related to the effectiveness of dialysis treatment and patient safety. However, most existing water production equipment relies on simple manual adjustment of reflux and discharge shut-off valves, or simple control of pumps and valves based on feedback from produced and concentrated water flow rates, to achieve the required water output. This simple, crude approach prevents the water production equipment from automatically and accurately adjusting its water output in response to changing operating conditions, often resulting in either constant or erratic water output. Furthermore, the overall level of automation and intelligence of the equipment is relatively low, and the need for manual adjustment inevitably increases the workload and skill requirements of maintenance personnel. Failure to adjust water output in a timely manner also leads to problems such as water and electricity waste.

[0003] Currently, the following working modes are mainly available on the market:

[0004] (1) Install a flow meter at the wastewater outlet of the reverse osmosis membrane to visually see the changes in the amount of reverse osmosis wastewater and manually adjust the water production according to the amount of wastewater. For example, patent CN201520738921.8 proposes a flow-adjustable ultrapure water machine for laboratory use.

[0005] (2) When the actual number of beds in the hospital is lower than the designed number of beds and patients are getting on and off the machines one after another, the designed operating water production volume far exceeds the actual patient demand, wasting energy and water resources. For example, CN202022137511.1 proposed a water production balance system for water production equipment for hemodialysis, which uses a two-stage reverse osmosis membrane (primary RO + secondary RO) to improve water quality, but the recovery rate is fixed (≤50%), and the concentrated water discharge volume cannot be dynamically adjusted according to the raw water quality, resulting in waste of water resources.

[0006] (3) The equipment is equipped with flow sensors to monitor the flow of produced water and concentrated water in real time, and automatically adjust the working status of the water pump or valve through the feedback mechanism to maintain the stability of the flow.

[0007] In response to the defects in water production efficiency and recovery rate optimization, water production dynamic regulation, key component life and maintenance, and lack of intelligence and predictive capabilities in the existing technologies, the present invention aims to develop a multi-dimensional, multi-conditional and predictive intelligent water production regulation and control method and system. Summary of the Invention

[0008] The present invention solves the following problems:

[0009] (1) Solve the problem that the designed water production far exceeds the actual water consumption, resulting in waste of water and electricity resources;

[0010] (2) Solve the problem of unstable water supply pressure when water consumption fluctuates greatly during the process of patients getting on and off the equipment;

[0011] (3) Solve the problem of abnormal back pressure in the water supply pipeline caused by the water supply volume being much greater than the water consumption;

[0012] (4) Solve the problems of single water production adjustment conditions, single adjustment method, poor adjustment performance, and simple control algorithm;

[0013] (5) Solve the problems of low level of equipment automation, intelligence and informationization and high manual workload.

[0014] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0015] In one aspect, the present invention provides a method for intelligently regulating water production in a hemodialysis device, wherein the device includes a balancer liquid level sensor, a pressure sensor, a secondary power frequency pump, and a secondary variable frequency pump, and comprises the following steps:

[0016] Step S1: Obtain the balancer liquid level height value, and preset three liquid level thresholds and change rates according to the total volume of the balancer: low liquid level, medium liquid level and high liquid level, as well as △ fast, △ slow and △ no;

[0017] Step S2: Determine whether the liquid level of the balancer is above the low liquid level and below the high liquid level. If so, calculate the rate of change of the liquid volume in the balancer according to the formula ΔV=ΔV1 / ΔT, where ΔV1 represents the change in the liquid volume in the balancer and ΔT represents the time interval;

[0018] Step S3: Different adjustment enable levels are set for the intelligent regulation of water production according to different situations. When the balancer liquid level is greater than the high liquid level or less than the low liquid level, the adjustment enable level is 0, indicating that the intelligent regulation should be exited; when the balancer liquid level is less than the high liquid level and greater than the low liquid level, the adjustment enable level is 1 or 2, indicating that the intelligent regulation should be turned on;

[0019] Step S4: When the adjustment enable level in step S3 is 1 or 2, the difference between the actual pressure value of the pressure sensor and the preset standard value is determined. When the actual pressure value of the pressure sensor is less than the preset standard value and the operating frequency of the secondary variable frequency pump is less than the preset first threshold frequency, the secondary variable frequency pump frequency increase action is executed; when the actual pressure value of the pressure sensor is less than or equal to the preset standard value and the operating frequency of the secondary variable frequency pump is greater than the preset second threshold frequency, the secondary variable frequency pump frequency reduction action is executed; otherwise, the secondary variable frequency pump frequency increase action is executed.

[0020] Preferably, after outputting the frequency adjustment completion signal in step S4, the method further includes:

[0021] Step S5: When the adjustment enable level in step S3 is 1 or 2, the standard water production is dynamically corrected based on the inlet water temperature and the reverse osmosis membrane usage time to obtain the actual reference water production. The calculation formula is:

[0022] Q 实 =Q 标 ×k1×k2

[0023] Among them, k1 is the temperature compensation coefficient, k2 is the membrane life attenuation coefficient, Q 实 is the actual water production, Q 标 is the standard water production;

[0024] Step S6: Taking the actual reference water production as the target value, the operating frequency of the secondary variable frequency pump and the start and stop status of the secondary power frequency pump are adjusted to make the water production flow rate match the water demand.

[0025] Preferably, after step S6, the method further includes:

[0026] Step S7: When the device is stable and |Q 实 -Q 标 | / Q 标 When ≤5%, the water production flow rate and the operating frequency of the secondary variable frequency pump are recorded at a fixed sampling interval, and the observation sequence is y1,…,y t , divide the sequence into t groups, and calculate the N-term moving average of the pump frequency at the end of each group. The calculation formula is as follows:

[0027]

[0028] by As the predicted value of pump frequency in the next period Pre-adjust the secondary variable frequency pump to The calculation formula is as follows:

[0029]

[0030] According to the above formula, the operating frequency corresponding to the water production demand in the next stage can be calculated to reduce the frequent intelligent adjustments caused by individual external factors.

[0031] In a second aspect, the present application further provides an intelligent water production adjustment system for a hemodialysis device, characterized in that it includes:

[0032] Balancer liquid level sensor;

[0033] Secondary RO membrane front pressure sensor and membrane back pressure sensor;

[0034] Produced water conductivity meter, temperature transmitter, produced water flow sensor;

[0035] Two-stage power frequency pump, two-stage variable frequency pump;

[0036] Central controller, connecting various sensors and actuators;

[0037] Pure water discharge valve, connected to the secondary water production pipeline.

[0038] Preferably, the central controller includes:

[0039] Liquid level change rate calculation module, used to calculate △V=△V1 / △T based on liquid level change △V1 and time △T;

[0040] Pressure-frequency synergy module for comparing actual pressure P 实 With standard pressure P 标 And output frequency adjustment instructions;

[0041] Temperature compensation module, stores temperature coefficient k1 and membrane life coefficient k2.

[0042] Preferably, the operating frequency adjustment range of the secondary variable frequency pump is 25-50Hz, and when the frequency is ≤25Hz, P 实 >P 标 When the secondary power frequency pump is turned off,

[0043] The intelligent control system of the present invention monitors the primary and secondary transmembrane pressure values, balancer liquid level value, conductivity value, water production value, secondary variable frequency pump operating frequency, inlet water temperature value, and reverse osmosis membrane usage time value in real time during the system operation process according to the number of patients and dialysis treatment needs. The above data is collected by the central controller, and the balancer liquid level and transmembrane pressure are used as the main factors, and their change rate is specifically calculated. Taking into account secondary factors such as conductivity, inlet water temperature, and reverse osmosis membrane usage time, the reference value of its standard water production is calculated. A high-performance central controller is used to achieve multi-dimensional and multi-conditional intelligent adjustment of water production. At the same time, the moving average method in the time series prediction algorithm is introduced to predict the water production required within a certain period of time in the future based on relevant historical data, thereby alleviating the problem of frequent adjustment, realizing dynamic and precise intelligent adjustment of water production, and constant pressure water supply, so that the system operates in the optimal working condition.

[0044] The present invention has the following beneficial effects:

[0045] (1) Intelligently adjust water production to meet the dialysis water needs of patients in different dialysis environments and improve water resource utilization efficiency;

[0046] (2) Reduce energy consumption and improve equipment efficiency through intelligent control;

[0047] (3) Reduce the risk of pressure buildup in the water supply pipeline and avoid water leakage caused by high-pressure operation;

[0048] (4) The pressure transmitter and the frequency converter work together to ensure stable water supply to the dialysis machine and improve the effect and safety of dialysis treatment; BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a system principle diagram provided by the present invention;

[0050] Figure 2 It is a flow chart of the method provided by the present invention;

[0051] Figure 3 It is a flow chart provided by a specific embodiment of the present invention. DETAILED DESCRIPTION

[0052] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

[0053] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0055] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are merely relational words determined for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure, and should not be understood as limitations on the present disclosure.

[0056] In this disclosure, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meaning of these terms in this disclosure based on specific circumstances, and they should not be construed as limiting this disclosure.

[0057] Ginseng Figure 1 and Figure 2 As shown, a method for intelligent regulation and control of water production for hemodialysis includes step S1: obtaining the liquid level height value of the balancer, and presetting three liquid level thresholds and change rates according to the total volume of the balancer: low liquid level, medium liquid level and high liquid level, as well as △ fast, △ slow and △ no;

[0058] Step S2: Determine whether the liquid level of the balancer is above the low liquid level and below the high liquid level. If so, calculate the rate of change of the liquid volume in the balancer according to the formula ΔV=ΔV1 / ΔT, where ΔV1 represents the change in the liquid volume in the balancer and ΔT represents the time interval;

[0059] Step S3: Different adjustment enable levels are set for the intelligent regulation of water production according to different situations. When the balancer liquid level is greater than the high liquid level or less than the low liquid level, the adjustment enable level is 0, indicating that the intelligent regulation should be exited; when the balancer liquid level is less than the high liquid level and greater than the low liquid level, the adjustment enable level is 1 or 2, indicating that the intelligent regulation should be turned on;

[0060] Step S4: When the adjustment enable level in step S3 is 1 or 2, the difference between the actual pressure value of the pressure sensor and the preset standard value is determined. When the actual pressure value of the pressure sensor is less than the preset standard value and the operating frequency of the secondary variable frequency pump is less than the preset first threshold frequency, the secondary variable frequency pump frequency increase action is executed; when the actual pressure value of the pressure sensor is less than or equal to the preset standard value and the operating frequency of the secondary variable frequency pump is greater than the preset second threshold frequency, the secondary variable frequency pump frequency reduction action is executed; otherwise, the secondary variable frequency pump frequency increase action is executed.

[0061] After the frequency adjustment completion signal is output in step S4, the method further includes:

[0062] Step S5: When the adjustment enable level in step S3 is 1 or 2, the standard water production is dynamically corrected based on the inlet water temperature and the reverse osmosis membrane usage time to obtain the actual reference water production. The calculation formula is:

[0063] Q 实 =Q 标 ×k1×k2

[0064] Among them, k1 is the temperature compensation coefficient, k2 is the membrane life attenuation coefficient, Q 实 is the actual water production, Q 标 is the standard water production;

[0065] Step S6: Taking the actual reference water production as the target value, the operating frequency of the secondary variable frequency pump and the start and stop status of the secondary power frequency pump are adjusted to make the water production flow rate match the water demand.

[0066] Step S7: When the device is stable and |Q 实 -Q 标 | / Q 标 When ≤5%, the water production flow rate and the operating frequency of the secondary variable frequency pump are recorded at a fixed sampling interval, and the observation sequence is y1,…,y t , divide the sequence into t groups, and calculate the N-term moving average of the pump frequency at the end of each group. The calculation formula is as follows:

[0067]

[0068] by As the predicted value of pump frequency in the next period Pre-adjust the secondary variable frequency pump to The calculation formula is as follows:

[0069]

[0070] According to the above formula, the operating frequency corresponding to the water production demand in the next stage can be calculated to reduce the frequent intelligent adjustments caused by individual external factors.

[0071] The present invention mainly relates to an intelligent control system for regulating the water production of this product, mainly involving the level LT1 of the balancer, the second-stage industrial frequency pump PUMP3, the second-stage water production variable-frequency pump PUMP4, the conductivity acquisition instrument CT2, the temperature transmitter TT, the pressure transmitters PT3 and PT4, and the flow sensor FI3 in the water production equipment for hemodialysis. It is characterized in that a high-performance central controller is set up. The central controller collects process physical quantities such as pressure, flow, temperature, level, and conductivity, and after specific calculations, converts them into control signals to control the start, stop, and operating frequency of two second-stage water production pumps, so as to achieve intelligent regulation of the water production.

[0072] In the water production equipment for hemodialysis, the main function of the balancer is to balance the water inlet volume and the water outlet volume and maintain the level at a certain value. Since the relationship between the water inlet volume and the water outlet volume is not linear, when the water consumption suddenly increases or decreases, the level of the balancer will also change accordingly. Therefore, according to the change of the level within a certain period of time, the change of the water consumption can be inferred. The specific method is as follows: A level sensor LT1 is configured in the balancer, and the analog quantity signal of 4-20 mA of the level is converted into a digital quantity signal through an analog-to-digital conversion module and transmitted to the central controller. The central controller calculates the liquid volume in the balancer according to the level signal, and calculates the liquid volume in the balancer by means of timing, so as to determine the change rate of the liquid volume in the balancer, and thus determine the change of the hemodialysis water consumption within a certain period of time, as the control enabling condition for implementing intelligent regulation. The steps of the method controlled by the central controller are as follows:

[0073] (1) The central controller first sets three reference values of the balancer level H, namely the low level, the medium level, and the high level, which are represented by H low, H medium, and H high respectively. Their relationship is H low < H medium < H high. Then, according to the three level values, four regions can be divided: below the low level, between the low level and the medium level, between the medium level and the high level, and above the high level. Since the situations below the low level and above the high level need to be avoided during normal two-stage water production, the central controller mainly calculates the change rate of the liquid volume in the region above the low level and below the high level. Three criteria can be established according to the change rate: fast change, slow change, and basically no change, which are represented by △ fast, △ slow, and △ none respectively. Their relationship is △ fast > △ slow > △ none.

[0074] (2) When the balancer level is in the region above the low level and below the high level, at every certain time interval △T, the central controller calculates the liquid volume V in the balancer according to the signal of the level sensor, and at the same time calculates the change amount △V1 of the liquid volume in the balancer within the time △T and the change rate △V of the liquid volume in the balancer. △V = △V1 / △T.

[0075] (3) The central controller implements control over the intelligent regulation of water production based on the following situations, and sets different regulation enabling levels according to different situations.

[0076] (3.1) When H < Hlow, it indicates that the water consumption is extremely large and the water inflow of the balancer cannot keep up. At this time, to protect each water production pump, stop the water production pump, and intelligent regulation should be exited, with the regulation enabling level being 0;

[0077] (3.2) When H > Hhigh, it indicates that the water consumption is extremely small or almost no water is used, and intelligent regulation should be exited, with the regulation enabling level being 0;

[0078] (3.3) When Hlow < H < Hhigh and △V < 0, |△V| ≥ △none, it indicates that the overall water consumption is stable, the water inflow and water use tend to be balanced, and intelligent regulation can be enabled, with the regulation enabling level being 1; (3.4) When Hlow < H < Hhigh and △V < 0, |△V| ≥ △slow, it indicates that the overall water consumption is gradually increasing instantaneously, and intelligent regulation is enabled, with the regulation enabling level being 2;

[0079] (3.5) When Hlow < H < Hhigh and △V < 0, |△V| ≥ △fast, it indicates that the overall water consumption is increasing rapidly instantaneously, and intelligent regulation is enabled, with the regulation enabling level being 2;

[0080] (3.6) When Hlow < H < Hhigh and △V > 0, |△V| ≥ △slow, it indicates that the overall water consumption is gradually decreasing instantaneously, and intelligent regulation can be enabled, with the regulation enabling level being 1;

[0081] (3.7) When Hlow < H < Hhigh and △V > 0, |△V| ≥ △fast, it indicates that the overall water consumption is decreasing rapidly instantaneously, and intelligent regulation is enabled, with the regulation enabling level being 2;

[0082] The change rate of the liquid volume in the balancer is used as the enabling condition for the intelligent regulation of water production. When the regulation enabling level is 0, intelligent regulation is not executed. When the regulation enabling level is 1, intelligent regulation is selectively executed according to the actual situation. When the regulation enabling level is 2, intelligent regulation must be executed.

[0083] In addition to the rate of change of the balancer liquid level, the rate of change of the produced water pressure is also used as an execution condition for the intelligent regulation of the produced water volume. When the water consumption is relatively low, if the equipment still maintains the previous water production, the pipeline pressure will rise to 2-3 times the preset pressure, and the back pressure on the water production side of the secondary reverse osmosis membrane will also far exceed the allowable value. When the water consumption increases, the amount of water in the pipeline decreases, and the pressure decreases accordingly. Therefore, detecting the produced water pressure can directly reflect the change in water consumption and can be used as an execution condition for the intelligent regulation of the produced water volume. The specific method is: a pressure sensor PT3 and PT4 are respectively set at the inlet and outlet of the secondary reverse osmosis membrane, and the analog signal of the pressure 4~20mA is converted into a digital signal through the analog conversion module and transmitted to the central controller, and the operating frequency of the secondary variable frequency pump PUMP4 is transmitted to the central controller. The central controller uses the rate of change of the membrane pressure and the operating frequency of the variable frequency pump as the execution condition for the intelligent regulation of the produced water volume. The steps of the method implemented by the central controller are:

[0084] (1) Set the standard value of the pressure before the membrane. When the actual pressure is between 0.5 and 1.2 times the standard value, the intelligent adjustment can be turned on and the adjustment enable level is 1;

[0085] (2) The standard value of the water supply pipe pressure after the membrane is set and is represented by "P standard", the actual pressure PT4 value collected by the central controller is represented by "P real", and the operating frequency value of the secondary variable frequency pump PUMP4 collected by the central controller is represented by "F". The control relationship between the three is as follows:

[0086] (2.1)P 实 <P 标 , F<50HZ, indicating that the water consumption increases instantly, and the operating frequency of the secondary variable frequency pump PUMP4 will increase, making Pactual=Pstandard;

[0087] (2.2)P 实 <P 标 , F=50HZ, indicating that the water consumption is maximum at the moment, and the operating frequency of the secondary variable frequency pump PUMP4 is at the maximum;

[0088] (2.3)P 实 >P 标 ,F>25HZ, indicating that the water consumption becomes smaller instantly, and the operating frequency of the secondary variable frequency pump PUMP4 will decrease, making Pactual=Pstandard;

[0089] (2.4)P 实 >P 标 ,F<25HZ, indicating that the water consumption is the smallest at the moment, and the secondary frequency conversion pump PUMP4 is running at the lower limit frequency. At this time, shut down the secondary power frequency pump PUMP3, increase the operating frequency of the secondary frequency conversion pump PUMP4, so that P 实 =P 标 ;

[0090] The conditions affecting the water production volume, in addition to the water production pressure, are also related to the inlet water temperature and the service time of the reverse osmosis membrane. The inlet water temperature and the service time control factor of the reverse osmosis membrane are also added in this intelligent water production volume regulation method. Since this water treatment equipment for hemodialysis is equipped with a water temperature compensation device, the temperature is generally controlled at about 25°C. According to the relationship between the water production volume of the reverse osmosis membrane and the temperature, the consideration of the temperature system is added in the control method, such as the water production temperature coefficient k1 at the standard 25°C, as the standard reference value of the water production flow rate. The service time of the reverse osmosis membrane is directly proportional to the conductivity of the produced water. The longer the service time, the larger the conductivity value of the produced water. The relationship coefficient K2 between the service time of the membrane and the conductivity of the produced water is added in the control method. The standard output is represented by "Q standard", and the actual output is represented by "Q actual". Then the reference value of the intelligent regulation of the water production volume is:

[0091] Since the water production volume may be stable within a certain value range for a long time during the stable water production of the system, in order to eliminate the adjustment variable caused by an accidental factor. A prediction of the operating state requirements for a period of time in the future based on historical data is also added in this control method. The specific method is: when the system is producing water normally, start to circularly count the water production flow rate and the corresponding operating frequency.

[0092] (1) Record a data of the water production flow rate every n minutes, continuously count for m hours, and then take the average value of these data.

[0093] (2) Compare the average value of the water production flow rate with the standard value. When the difference between the two is less than 5%, it means that the water production and water use of the whole system are stable, and the basic trend of the predicted target water production volume fluctuates around the standard value. A pre-control model of the operating frequency corresponding to the target water production volume can be established by using a simple moving average method.

[0094] (3) Establish a prediction model of the operating frequency. First, divide the 60m / n groups of operating frequencies recorded into t equal parts. Let the observation sequence be y1,…,, and take the number of terms N of the moving average <t. The calculation formula of the simple moving average value at one time is:

[0095]

[0096] The established operating frequency model:

[0097]

[0098] According to the above formula, the operating frequency corresponding to the operating water production volume requirement in the next stage can be deduced to reduce the frequent intelligent regulation caused by the influence of individual external factors. When the changes in the water production volume and the operating frequency data are greater than 5%, it means that the external water use fluctuates greatly, and the system intelligently regulates the water production volume in real time to ensure the stability of water use.

[0099] The invention also has the following beneficial effects:

[0100] (1) Based on the characteristics of the operation of dialysis machines and blood purification departments, this new technology is used to intelligently adjust the operating conditions of the hemodialysis water production equipment to ensure that the pressure on the secondary water production side is 4 bar without large fluctuations;

[0101] (2) According to the changes in water demand such as patients getting on and off the machine and nighttime circulation, the equipment operating conditions are intelligently adjusted to save energy and reduce emissions, thereby improving resource utilization;

[0102] (3) Automatically collect and update data on rated operating conditions, automatically compare abnormal data, and analyze and adjust the causes of abnormalities.

[0103] Example

[0104] like Figure 3 As shown, taking the hemodialysis equipment with a rated water output of 3.6T / H (water temperature 25℃) as an example, the pure water pipeline is made of stainless steel, the pipe length is 300m, the pipe diameter is DN32, and the inlet water temperature is about 25℃.

[0105] After enabling two-stage water production mode, when the balancer liquid level is above the mid-level, electric valve FV3 opens, starting the first-stage variable-frequency pump PUMP2 and initiating low-pressure flushing. When the flushing time reaches the set time, electric valve FV3 closes, maintaining the initial level of the first-stage variable-frequency pump PUMP2, and the high-flow, low-pressure flushing ends. Normal two-stage water production begins. The first-stage variable-frequency pump PUMP1 starts, followed by a 5-second delay. The second-stage variable-frequency pump PUMP4 starts, followed by a 2-second delay. Diaphragm valves 101, 201, and 202 are adjusted to a certain opening to maintain a pressure of 8-10 bar before the reverse osmosis membrane. The second-stage permeate pressure PT4 is monitored, with a constant pressure of 4 bar. After a period of stable system operation, the second-stage permeate flow rate FI3 and the operating frequency of the second-stage variable-frequency pump PUMP4 are recorded. The balancer liquid level LT1 is monitored, and the rate of change of the liquid volume in the balancer determines whether to enable intelligent regulation. The second-stage permeate pressure PT4 is monitored, and the rate of change of the pressure determines whether to enable intelligent regulation. By intelligently adjusting the operating frequency of the secondary variable frequency pump PUMP4 and the operating status of the secondary power frequency pump PUMP3, the water supply pressure is always stable at 4 bar, the water production flow rate is within the standard range (2.4±0.2T / H~4.5±0.2T / H), and the secondary water quality conductivity is <10μS / cm.

[0106] (1) During the equipment commissioning phase or before patients are put on the machine, the consumption of pure water for hemodialysis is extremely small. If the equipment maintains a water output of 3.6 T / H, the pipeline pressure will rise to 2-3 times the preset pressure, and the back pressure on the water production side of the secondary reverse osmosis membrane will also far exceed the allowable value, resulting in a decrease in equipment stability and an increase in the risk of pipeline leakage. By monitoring the fluctuations in water consumption, the water production can be reduced to about 2.0 T / H by adjusting the water pump frequency to maintain stable pipeline pressure and no back pressure on the water production side.

[0107] (2) When the dialysis room is running at full capacity, or the dialysis machine is in the disinfection stage (the water demand increases by 20% compared with the normal dialysis stage), in order to ensure the stability of the water supply pipeline pressure, the system is operated at a higher frequency, and the water production is increased by 25% based on the rated water production to meet the supply demand and avoid water shortage or low pressure alarm of the dialysis machine;

[0108] (3) After the water production system is stable, record the water production and operating frequency. Collect data once every minute for 2 hours continuously, and take the average value of 120 water production data. When the value is between 3.42 and 3.78T / H (with the rated water production of 3.6T / H as the standard value), it means that the water production is stable, and the approximate operating frequency in the next cycle can be predicted. Using the moving average, divide the 120 operating frequencies into 6 equal parts, take the average value of every 20 data, and take the average number of items as 4. The operating frequency pattern of the 7th 20 minutes is as follows:

[0109]

[0110] (4) Automatically collect and store equipment operation data, establish a large database of the specific working conditions of each device, compare and analyze the real-time operation data with the database, and automatically adjust in abnormal situations to ensure that the equipment operates in the best working conditions.

[0111] (5) In summer, the temperature is high. A temperature transmitter is installed on the secondary water production side to monitor the outlet water temperature. When the temperature exceeds the temperature that the human body can withstand (which can be set), the system automatically discharges from FV14 until the temperature drops below the set lower limit temperature to ensure the patient's dialysis safety.

[0112] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A method for intelligently regulating water production in a hemodialysis device, wherein the device comprises a balancer level sensor, a pressure sensor, a secondary power frequency pump, and a secondary variable frequency pump, characterized in that: The following steps are involved: Step S1: Obtain the balancer liquid level height value, and preset three liquid level thresholds and change rates according to the total volume of the balancer: low liquid level, medium liquid level and high liquid level, as well as △ fast, △ slow and △ no; Step S2: Determine whether the liquid level of the balancer is above the low liquid level and below the high liquid level. If so, calculate the rate of change of the liquid volume in the balancer according to the formula ΔV=ΔV1 / ΔT, where ΔV1 represents the change in the liquid volume in the balancer and ΔT represents the time interval; Step S3: Different adjustment enable levels are set for the intelligent regulation of water production according to different situations. When the balancer liquid level is greater than the high liquid level or less than the low liquid level, the adjustment enable level is 0, indicating that the intelligent regulation should be exited; when the balancer liquid level is less than the high liquid level and greater than the low liquid level, the adjustment enable level is 1 or 2, indicating that the intelligent regulation should be turned on; Step S4: When the adjustment enable level in step S3 is 1 or 2, the difference between the actual pressure value of the pressure sensor and the preset standard value is determined. When the actual pressure value of the pressure sensor is less than the preset standard value and the operating frequency of the secondary variable frequency pump is less than the preset first threshold frequency, the secondary variable frequency pump frequency increase action is executed; when the actual pressure value of the pressure sensor is less than or equal to the preset standard value and the operating frequency of the secondary variable frequency pump is greater than the preset second threshold frequency, the secondary variable frequency pump frequency reduction action is executed; otherwise, the secondary variable frequency pump frequency increase action is executed.

2. The method according to claim 1, characterized in that After the frequency adjustment completion signal is output in step S4, the method further includes: Step S5: When the adjustment enable level in step S3 is 1 or 2, the standard water production is dynamically corrected based on the inlet water temperature and the reverse osmosis membrane usage time to obtain the actual reference water production. The calculation formula is: ， in, is the temperature compensation coefficient, is the membrane life attenuation coefficient, is the actual water production, is the standard water production; Step S6: Taking the actual reference water production as the target value, the operating frequency of the secondary variable frequency pump and the start and stop status of the secondary power frequency pump are adjusted to make the water production flow rate match the water demand.

3. The method according to claim 2, characterized in that After step S6, the method further includes: Step S7: When the device is stable, When the water production flow rate and the operating frequency of the secondary variable frequency pump are recorded at a fixed sampling interval, the observation sequence is y1,…, , divide the sequence into t groups, and calculate the N-term moving average of the pump frequency at the end of each group. The calculation formula is as follows: ， by As the predicted value of pump frequency in the next period , pre-adjust the secondary variable frequency pump to The calculation formula is as follows: ， According to the above formula, the operating frequency corresponding to the water production demand in the next stage can be calculated to reduce the frequent intelligent adjustments caused by individual external factors.

4. An intelligent water production adjustment system for hemodialysis equipment, characterized in that: include: The data acquisition module includes: a liquid level sensor installed in the balancer, pressure sensors installed at the inlet and outlet of the secondary reverse osmosis membrane, a temperature transmitter to monitor the inlet water temperature, a conductivity collector to detect the conductivity of the produced water, and a flow sensor to measure the produced water flow rate; The central controller is connected to the data acquisition module by signal, and is internally configured with: a dynamic compensation unit for performing temperature compensation and membrane life attenuation compensation on the standard water production according to the inlet water temperature and the accumulated use time of the reverse osmosis membrane, and outputting the actual reference water production after compensation; The regulation enable decision unit is used to generate a regulation enable level signal based on the liquid level signal, pressure signal and preset liquid level threshold and pressure threshold; the prediction and pre-control unit is used to generate a frequency prediction value based on the historical water production flow and water pump frequency data when the system is stable; The execution module includes: a secondary water production frequency conversion pump controlled by the central controller, whose operating frequency is driven by the adjustment enable level signal and / or the frequency prediction value; a secondary water production power frequency pump controlled by the central controller, whose start and stop status is driven by the adjustment enable level signal.

5. The system according to claim 4, characterized in that: The dynamic compensation unit includes: a temperature compensation submodule, which has built-in data on the corresponding relationship between the water production of the reverse osmosis membrane and the temperature, and outputs a temperature compensation coefficient based on the deviation between the real-time inlet water temperature and 25 degrees Celsius; a membrane attenuation compensation submodule, which outputs a membrane life attenuation coefficient based on the ratio of the initial conductivity of the reverse osmosis membrane to the real-time conductivity.

6. The system according to claim 4, wherein: The prediction and pre-control unit includes: a data sampling circuit that records the water production flow rate and the operating frequency of the secondary water production variable frequency pump at fixed time intervals; a moving average calculation circuit that generates a frequency prediction value by performing equal-weighted average calculation on multiple sets of frequency data collected within a continuous statistical period.

7. The system according to claim 4, characterized in that: The fixed time interval is one minute, the continuous statistical duration is two hours, the number of groupings of the multiple sets of frequency data is six, and the number of data items for the equal-weighted average calculation is four.

8. The system according to claim 4, characterized in that: The regulation enable decision unit includes: a liquid level comparator, which outputs a regulation enable level signal when the liquid level value is between a low liquid level threshold and a high liquid level threshold and the absolute value of the liquid level change rate exceeds a preset change rate threshold; and a pressure comparator, which outputs a regulation enable level signal when the produced water pressure value exceeds the range of 0.5 times to 1.2 times the standard pressure value.

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