Self-adaptive adjustment control method for variable frequency water pump of heat supply pump unit

Abstract

The invention relates to a self-adaptive adjustment control method for a variable frequency water pump of a heat supply pump unit. Comprising the steps that S1, a lift-flow characteristic curve of a variable frequency water pump at each rotating speed is obtained, S2, according to the number of started user end equipment, the variable frequency water pump conducts frequency increasing and frequency decreasing operation, the flow and lift of the variable frequency water pump at each rotating speed are recorded, and a lift-flow characteristic curve of a current pipeline is obtained through fitting; s3, according to the determined required water flow, obtaining a working point in the current state and the rotating speed of the variable frequency water pump; s4, according to the flow feedback of each tail end, after the optimal working point in the current state is obtained, whether the current water flow of each tail end meets the rated flow of the tail end or not is checked; if yes, executing according to the current rotating speed, and if not, performing frequency modulation until the condition is met. According to the invention, the difficulty of real-time matching of lift and flow is effectively solved, and the stability and energy efficiency of the unit are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of dual-supply heat pump units, and more specifically, to a method for adaptively regulating and controlling a variable frequency water pump of a heat pump unit. Background Art

[0002] The traditional integrated two-way heat pump unit in China has cooling and heating functions. Its main equipment includes compressors, finned heat exchangers, shell-and-tube heat exchangers, water pumps, etc. In the domestic integrated two-way heat pump units, most manufacturers use fixed-frequency water pumps. In the early stage of design, the rated flow is calculated according to the rated capacity of the unit, and a relatively load-adapted water pump is selected from a series of water pumps. However, since the development of the water pump industry, its service and development targets are more user water supply, large-scale equipment water supply, and chemical use. Models developed specifically for heat pumps account for a small number. Therefore, it is inevitable that the load is large and the energy efficiency is poor in the design of heat pumps; if the model is small, the head and flow are insufficient, and the optimal solution cannot be achieved. During the operation of the unit, the fixed-frequency water pump has been running at the rated / fixed frequency, and the energy efficiency is also very poor. In the actual user scenario, the flow of the pipeline often changes greatly due to the start and stop of the fixed-frequency water pump, resulting in water hammer sound in the water system, affecting the user experience. Among the few manufacturers that use variable frequency water pumps, they generally determine the required flow rate by real-time monitoring of the cooling / heat required by the system, thereby controlling the speed of the water pump. There is a lack of calculation and matching of the head required by the system at this time. In addition, there is a general lack of judgment on the minimum head and minimum flow rate, and the reliability, stability and energy efficiency of the unit need to be improved. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art that lacks judgment and matching of head and minimum flow, resulting in low stability and energy efficiency of the unit, and to provide an adaptive adjustment control method for a variable frequency water pump of a heating pump unit, which effectively solves the difficulty of real-time matching of head and flow, and effectively improves the stability and energy efficiency of the unit.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for adaptively adjusting and controlling a variable frequency water pump of a heat pump unit is provided, comprising the following steps: S1. Obtain the head-flow characteristic curve of the variable frequency water pump at each speed S2. The variable frequency pump increases or decreases the frequency according to the number of user terminal devices turned on, and records the flow rate and head at each speed of the variable frequency pump, and fits the head-flow characteristic curve of the current pipeline; S3. Determine the required water flow rate according to the number of user terminal devices turned on, and obtain the optimal working point and the speed of the variable frequency pump under the current state; wherein the working point is the intersection of the head-flow characteristic curve of the pipeline and the head-flow characteristic curve of the variable frequency pump; S4. Based on the flow feedback from each terminal, after obtaining the optimal working point under the current state, check whether the current water flow of each terminal meets the rated flow of the terminal; if it meets, execute according to the current speed; if not, adjust the frequency until it meets.

[0005] The present invention provides an adaptive regulation and control method for a variable frequency water pump of a heat pump unit. According to different usage conditions of user terminal equipment, the head-flow characteristic curve of the pipeline in each case is calculated by regulating the speed and frequency of the variable frequency water pump itself; the head requirement of the waterway is calculated by the head-flow characteristic curve of the pipeline, and the flow requirement is supplied on demand according to the actual usage of the user's terminal equipment, so that the flow change of the entire water system is small, the problem of water hammer is effectively solved, the stability of the system is improved, and the energy efficiency of the system is also improved; after the speed regulation is stabilized, a detection stage is added to further ensure the reliability of the water system.

[0006] Preferably, in step S1, the head-flow characteristic curve of the variable frequency water pump at each speed is obtained according to the data provided by the variable frequency water pump manufacturer or through testing; the real-time flow of the pipeline is monitored by the flow feedback function of the variable frequency water pump or by setting a flow meter at the outlet of the variable frequency water pump; the real-time head at the outlet of the variable frequency water pump is monitored by setting a pressure gauge at the outlet of the variable frequency water pump. The performance curve of the variable frequency water pump is generally the performance curve of the maximum speed specified in the specification, and the speed is automatically adjusted according to the system requirements. At this time, the characteristic curve moves up (preferably not more than 6%) and down (preferably not more than 40%) in parallel, and the head-flow performance curve of the corresponding variable frequency water pump at each speed can be obtained according to the manufacturer's data or tests.

[0007] The pipeline characteristic curve is numerically equal to , a is the comprehensive coefficient of pipeline resistance, Q is the water flow rate of the pipeline, but since the pipeline conditions of each user are inconsistent, the length, diameter, and number of elbows and tees are inconsistent, the accuracy of coefficient a cannot be guaranteed; further, the change of the end will cause the change of the pipeline characteristic curve, and the water pump frequency conversion will also cause the change of the water pump performance curve, but after stabilization, the two will be in a balance. Therefore, in the present invention, the intersection of the pipeline head-flow characteristic curve and the head-flow performance curve of the variable frequency water pump is set as the working point of the waterway at this time.

[0008] Preferably, in step S2, the variable frequency water pump is started and the frequency is increased to make the real-time flow rate Q of the unit 实 Reach the minimum flow rate Q of the unit min If Q 实 ±ΔQ=Q min , the unit runs stably at the minimum flow rate for the preset time; if Q 实 ±ΔQ is greater or less than Q minAfter running for a preset time, check again. If multiple checks fail to meet the requirements, stop the machine to troubleshoot the fault. ΔQ is the set allowable fluctuation range of water flow. After the equipment is started, first check whether the entire system can operate normally to ensure the stability of subsequent frequency modulation and avoid affecting stability and accuracy due to system failure.

[0009] Preferably, in step S2, it also includes determining the speed adjustment range of the variable frequency water pump of the current user, assuming that the speed adjustment range of the variable frequency water pump is R1~Rn: if the minimum flow speed r min ≤R1, then the current user's variable frequency pump speed adjustment range is R1~Rn; if the minimum flow speed r min >R1, then the current user's variable frequency water pump speed adjustment range is r min ~ Rn; the speed adjustment range is divided into three speed intervals, the first speed interval is r min / R1~(R1+ΔR), the second speed range is (R1+ΔR)~(R1+2ΔR), and the third speed range is (R1+2ΔR)~Rn; where ΔR=(Rn~R1) / 3. Assume that the speed adjustment range of the variable frequency water pump is 1800r~3200r; if the minimum flow speed r min ≤1800r, then the current user's variable frequency pump speed adjustment range is 1800r~3200r; if the minimum flow speed r min >1800r, then the current user's variable frequency water pump speed adjustment range is r min ~3200r; the speed adjustment range is divided into three speed intervals, the first speed interval is r min / 1800r~2300r, the second speed range is 2300r~2800r, and the third speed range is 2700r~3200r.

[0010] The present invention is based on the frequency conversion range of the variable frequency water pump and particularly emphasizes protective measures for the minimum flow of the unit. Moreover, through the flow feedback / flow meter real-time monitoring of the variable frequency water pump, the effect of removing the water flow switch can be achieved, thereby reducing costs and improving quality.

[0011] Preferably, the rated water flow is calculated according to the rated capacity of the unit, and 60% of the rated water flow of the unit is set as the minimum flow of the unit. The frequency corresponding to the minimum flow is the minimum flow speed r of the unit. min .

[0012] Preferably, the step S2 specifically includes: If the number of user terminal devices turned on n=1, the speed of the variable frequency pump changes from r min / R1, Nr rises every t seconds, and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed; If the number of user terminal devices turned on is n=2, the speed of the variable frequency water pump increases by Nr every t seconds from (R1+ΔR), and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed; If the number of user terminal devices turned on is n=3, the speed of the variable frequency water pump increases by Nr every t seconds from (R1+2ΔR), and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed.

[0013] Preferably, in step S2: If the number of user terminal devices turned on n=1, the maximum water flow value Q1 detected by the variable frequency water pump in the current speed range max <Q 总 , Q 总 is the total water flow required by the current water system, the variable frequency water pump speed is adjusted to the next speed range; if the minimum water flow value Q1 is detected min >Q 总 , then according to the minimum flow speed r min Run; when the detected water flow value Q1=Q 总 , according to the working points of each speed in the speed range, the head-flow characteristic curve of the current pipeline is fitted again; If the number of user terminal devices turned on n=2, the maximum water flow value detected by the variable frequency water pump in the current speed range is Q2 max <Q 总 , the variable frequency pump speed will be adjusted to the next speed range; if the minimum water flow value Q2 is detected min >Q 总 , the variable frequency water pump speed is adjusted to the next speed range; when the detected water flow value Q2=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the current pipeline is fitted again; If the number of user terminal devices turned on n=3, the maximum water flow value detected by the variable frequency water pump in the current speed range is Q3 max <Q 总 , it runs at the maximum speed; if the minimum water flow value detected is Q3 min >Q 总 , the variable frequency water pump speed is adjusted to the next speed range; when the detected water flow value Q3=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the current pipeline is fitted again.

[0014] In the stage of fitting the pipeline head-flow characteristic curve, the present invention increases and decreases the speed in different zones, so that the flow change of the entire water system is small, the problem of water hammer sound is effectively solved, and the service life of the system is increased.

[0015] Preferably, in step S3, the rated water flow required at each end is Q 末 When the user turns on a terminal device, the system water flow is slightly greater than Q 末 , use Q' 末 express; If the number of user terminal devices turned on n=1, Q 总 =Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on is n=2, Q 总 =2Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on n=3, Q 总 =3Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the pump needs to provide, and get the optimal speed of the pump.

[0016] Preferably, in step S4, the flow rate Q of the opened terminal device is detected. 检 , check the flow Q of each opened terminal device 检 Whether it meets the rated flow rate Q of the terminal equipment 末 , if Q 检 ≥Q 末 , it runs at the current speed; if Q 检 <Q 末 , then increase the speed of the variable frequency water pump until Q 检 ≥Q 末 The present invention adds a detection stage after the speed regulation is stabilized to further ensure the reliability of the water system.

[0017] The present invention also provides an adaptive regulation control system for a variable frequency water pump of a heat pump unit, comprising a heat pump unit, a variable frequency water pump connected to the water inlet end of the heat pump unit, a plurality of terminal devices connected to the water outlet end of the heat pump unit and arranged in parallel, a water tank connecting the variable frequency water pump and the terminal devices, a detection unit arranged in the water circuit for detecting water flow or pipeline pressure, and a controller communicatively connected to the variable frequency water pump and the detection unit, wherein the controller executes the adaptive regulation control method for the variable frequency water pump described above.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides an adaptive regulation and control method for a variable frequency water pump of a heat pump unit. According to different usage conditions of user terminal equipment, the head-flow characteristic curve of the pipeline in each case is calculated by regulating the speed and frequency of the variable frequency water pump itself; the head requirement of the waterway is calculated by the head-flow characteristic curve of the pipeline, and the flow requirement is supplied on demand according to the actual usage of the user's terminal equipment, so that the flow change of the entire water system is small, the problem of water hammer is effectively solved, the stability of the system is improved, and the energy efficiency of the system is also improved; after the speed regulation is stabilized, a detection stage is added to further ensure the reliability of the water system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flow chart of a method for adaptively adjusting and controlling a variable frequency water pump of a heat pump unit.

[0020] Figure 2 This is a schematic diagram of the system structure in Example 3.

[0021] In the attached drawings: 10, heat pump unit; 20, variable frequency water pump; 30, terminal equipment; 40, water tank; 51, first pressure gauge; 52, flow meter; 53, second pressure gauge. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific implementation methods. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams, not actual drawings, and cannot be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0023] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0024] Embodiment 1 This embodiment is a first embodiment of a method for adaptively adjusting and controlling a variable frequency water pump of a heat pump unit. Figure 1 As shown, the following steps are included: S1. Obtain the head-flow characteristic curve of the variable frequency water pump at each speed S2. The variable frequency pump increases or decreases the frequency according to the number of user terminal devices turned on, and records the flow rate and head at each speed of the variable frequency pump, and fits the head-flow characteristic curve of the current pipeline; S3. Determine the required water flow rate according to the number of user terminal devices turned on, and obtain the optimal working point and the speed of the variable frequency water pump under the current state; wherein the working point is the intersection of the head-flow characteristic curve of the pipeline and the head-flow characteristic curve of the variable frequency water pump.

[0025] S4. Based on the flow feedback from each terminal, after obtaining the optimal working point under the current state, check whether the current water flow of each terminal meets the rated flow of the terminal; if it meets, execute according to the current speed; if not, adjust the frequency until it meets.

[0026] In step S1, the head-flow characteristic curve of the variable frequency water pump at each speed is obtained according to the data provided by the variable frequency water pump manufacturer or through testing; the real-time flow of the pipeline is monitored through the flow feedback function of the variable frequency water pump or by setting a flow meter at the outlet of the variable frequency water pump; the real-time head of the outlet of the variable frequency water pump is monitored by setting a pressure gauge at the outlet of the variable frequency water pump. The performance curve of the variable frequency water pump is generally the performance curve of the maximum speed specified in the specification book, and the speed is automatically adjusted according to the system requirements. At this time, the characteristic curve moves up (preferably not more than 6%) and down (preferably not more than 40%) in parallel. The head-flow performance curve of the corresponding variable frequency water pump at each speed can be obtained according to the manufacturer's data or tests.

[0027] The pipeline characteristic curve is numerically equal to , a is the comprehensive coefficient of pipeline resistance, Q is the water flow rate of the pipeline, but since the pipeline conditions of each user are inconsistent, the length, diameter, and number of elbows and tees are inconsistent, the accuracy of coefficient a cannot be guaranteed; further, the change of the end will cause the change of the pipeline characteristic curve, and the water pump frequency conversion will also cause the change of the water pump performance curve, but after stabilization, the two will be in a balance. Therefore, in the present invention, the intersection of the pipeline head-flow characteristic curve and the head-flow performance curve of the variable frequency water pump is set as the working point of the waterway at this time.

[0028] In this embodiment, the rated water flow is calculated according to the rated capacity of the unit, and 60% of the rated water flow of the unit is set as the minimum flow of the unit. The frequency corresponding to the minimum flow is the minimum flow speed r of the unit. min .

[0029] In step S2, the variable frequency water pump starts and increases the frequency to make the real-time flow rate Q 实 Reach the minimum flow rate Q of the unit min If Q 实 ±ΔQ=Q min , the unit runs stably at the minimum flow rate for the preset time; if Q 实 ±ΔQ is greater or less than Q min After running for a preset time, check again. If multiple checks fail to meet the requirements, stop the machine to troubleshoot the fault. ΔQ is the set allowable fluctuation range of water flow. After the equipment is started, first check whether the entire system can operate normally to ensure the stability of subsequent frequency modulation and avoid affecting stability and accuracy due to system failure.

[0030] In step S2, it also includes determining the speed adjustment range of the variable frequency water pump of the current user, assuming that the speed adjustment range of the variable frequency water pump is R1~Rn: if the minimum flow speed r min ≤R1, then the current user's variable frequency pump speed adjustment range is R1~Rn; if the minimum flow speed r min >R1, then the current user's variable frequency water pump speed adjustment range is r min ~ Rn; the speed adjustment range is divided into three speed intervals, the first speed interval is r min / R1~(R1+ΔR), the second speed range is (R1+ΔR)~(R1+2ΔR), and the third speed range is (R1+2ΔR)~Rn; among which, ΔR=(Rn~R1) / 3.

[0031] The present invention is based on the frequency conversion range of the variable frequency water pump and particularly emphasizes protective measures for the minimum flow of the unit. Moreover, through the flow feedback / flow meter real-time monitoring of the variable frequency water pump, the effect of removing the water flow switch can be achieved, thereby reducing costs and improving quality.

[0032] Step S2 specifically includes: If the number of user terminal devices turned on n=1, the speed of the variable frequency pump changes from r min / R1, Nr rises every t seconds, and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed; If the number of user terminal devices turned on is n=2, the speed of the variable frequency water pump increases by Nr every t seconds from (R1+ΔR), and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed; If the number of user terminal devices turned on is n=3, the speed of the variable frequency water pump increases by Nr every t seconds from (R1+2ΔR), and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed.

[0033] In addition, in step S2: If the number of user terminal devices turned on n=1, the maximum water flow value Q1 detected by the variable frequency water pump in the current speed range max <Q 总 , Q 总 is the total water flow required by the current water system, the variable frequency water pump speed is adjusted to the next speed range; if the minimum water flow value Q1 is detected min >Q 总 , then according to the minimum flow speed r min Run; when the detected water flow value Q1=Q 总 , according to the working points of each speed in the speed range, the head-flow characteristic curve of the current pipeline is fitted again; If the number of user terminal devices turned on n=2, the maximum water flow value detected by the variable frequency water pump in the current speed range is Q2 max <Q 总 , the variable frequency pump speed will be adjusted to the next speed range; if the minimum water flow value Q2 is detected min >Q 总 , the variable frequency water pump speed is adjusted to the next speed range; when the detected water flow value Q2=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the current pipeline is fitted again; If the number of user terminal devices turned on n=3, the maximum water flow value detected by the variable frequency water pump in the current speed range is Q3 max <Q 总 , it runs at the maximum speed; if the minimum water flow value detected is Q3 min >Q 总 , the variable frequency water pump speed is adjusted to the next speed range; when the detected water flow value Q3=Q总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the current pipeline is fitted again.

[0034] When the detected water flow value Q1=Q 总 / Q2=Q 总 / Q3=Q 总 , indicating that there is an optimal water flow operating point in this range. In this case, the rotation speed in this range should be fine-tuned to fit a more accurate pipeline head-flow characteristic curve.

[0035] In the stage of fitting the pipeline head-flow characteristic curve, the present invention increases and decreases the speed in different zones, so that the flow change of the entire water system is small, the problem of water hammer sound is effectively solved, and the service life of the system is increased.

[0036] In step S3, the rated water flow required at each terminal is Q 末 When the user turns on a terminal device, the system water flow is slightly greater than Q 末 , use Q' 末 express; If the number of user terminal devices turned on n=1, Q 总 =Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on is n=2, Q 总 =2Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on n=3, Q 总 =3Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the pump needs to provide, and get the optimal speed of the pump.

[0037] In step S4, the flow rate Q of the opened terminal device is detected 检 , check the flow Q of each opened terminal device 检 Whether it meets the rated flow rate Q of the terminal equipment 末 , if Q 检 ≥Q 末 , it runs at the current speed; if Q 检 <Q 末, then increase the speed of the variable frequency water pump until Q 检 ≥Q 末 The present invention adds a detection stage after the speed regulation is stabilized to further ensure the reliability of the water system.

[0038] The present embodiment provides an adaptive regulation and control method for a variable frequency water pump of a heat pump unit. According to different usage conditions of user terminal equipment, the variable frequency water pump itself regulates speed and frequency to calculate the head-flow characteristic curve of the pipeline in each case; the head requirement of the waterway is calculated through the head-flow characteristic curve of the pipeline, and the flow requirement is supplied on demand according to the actual usage of the user's terminal equipment, so that the flow change of the entire water system is small, the problem of water hammer is effectively solved, the stability of the system is improved, and the energy efficiency of the system is also improved; after the speed regulation is stabilized, a detection stage is added to further ensure the reliability of the water system.

[0039] Embodiment 2 This embodiment is a second embodiment of a heat pump unit variable frequency water pump adaptive regulation control method, comprising the following steps: Step 1: In heating mode, the unit runs and the variable frequency water pump starts.

[0040] Step 2: Start the variable frequency water pump, slowly increase the frequency for 1 minute, detect the real-time flow rate Q of the unit, and make the real-time flow rate of the unit reach the minimum flow rate r of the unit after 1 minute min , at this time the speed is the minimum flow speed of the unit r min : If the real-time flow rate of the unit Q = Q min (±0.1m^3 / h), stable operation at the minimum flow platform of the unit for 15s If the real-time flow rate of the unit Q> or <Q min (±0.1m^3 / h), test again after 15s; if the conditions are not met three times, report a water flow switch failure and shut down to troubleshoot.

[0041] Step 3: The unit's minimum flow platform runs stably for 15 seconds.

[0042] Step 4: Determine the current user's water pump speed adjustment range. In this embodiment, the frequency adjustment range of the variable frequency water pump is 1800r~3200r: If the minimum flow rate speed r min ≤1800r, the current user's pump speed adjustment range is 1800r-3200r If the minimum flow rate speed r min >1800r, then the current user's pump speed adjustment range is r min -3200r Furthermore, the speed adjustment range is divided into three intervals: the first speed interval is rmin / 1800r-2300r, the second speed range 2300r-2800r, the third speed range 2700r-3200r.

[0043] Step 5: Check the number of user terminal devices turned on: (1) If the number of user terminal devices turned on n=1, the speed of the variable frequency water pump changes from r min / 1800r, rise 100r every 10s, and record the flow rate and head at each speed; 1 minute later, fit the head-flow characteristic curve of the pipeline through the working points of each speed.

[0044] If the flow value Q1 is detected at each speed in this range max <Q 总 , the pump speed is adjusted to the next interval; If Q1 min >Q 总 , running at the minimum flow rate and speed, indicating that the variable frequency pump is too large; When Q1=Q 总 , according to the working points of each speed in the interval, the pipeline characteristic curve is fitted again.

[0045] (2) If n = 2, the speed of the variable frequency water pump increases from 2300r to 100r every 10s, and the flow rate and head at each speed are recorded; after 1 minute, the head-flow characteristic curve of the pipeline is fitted through the working points at each speed.

[0046] If the flow value Q2 is detected at each speed in this range max <Q 总 , the pump speed is adjusted to the next interval; If the flow value Q2 is detected at each speed in this range min >Q 总 , the pump speed is modulated to the next interval; When Q2=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the pipeline is fitted again.

[0047] (3) If n = 3, the speed of the variable frequency water pump increases from 2700r to 100r every 10s, and the flow rate and head at each speed are recorded; after 1 minute, the head-flow characteristic curve of the pipeline is fitted through the working points at each speed.

[0048] If the flow value Q3 is detected at each speed in this range max <Q 总 , running at the maximum speed, indicating that the variable frequency pump is too small; If the flow value Q3 is detected at each speed in this range min >Q总 , the pump speed is modulated to the next interval; When there exists Q3=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the pipeline is fitted again.

[0049] Step 6: Determine the total water flow required by the current water system based on the number of terminal openings: Q 总 =nQ' 末 , the rated water flow required at each end is Q 末 When the user turns on a terminal device, the system water flow is slightly greater than Q 末 , use Q' 末 express.

[0050] If the number of user terminal devices turned on n=1, Q 总 =Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on is n=2, Q 总 =2Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on n=3, Q 总 =3Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the pump needs to provide, and get the optimal speed of the pump.

[0051] Step 7: Detect the flow feedback Q of the opened terminal 检 , check the water flow Q before each opened terminal 检 Whether the rated flow Q at the end is met 末 : If Q 检 ≥Q 末 , the speed remains unchanged If Q 检 <Q 末 , increase the pump speed until Q 检 ≥Q 末 .

[0052] Embodiment 3 This embodiment is an embodiment of a heat pump unit 10 variable frequency water pump 20 adaptive regulation control system. Figure 2 As shown, in this embodiment, a heat pump unit 10 is included, a variable frequency water pump 20 connected to the water inlet end of the heat pump unit 10, a plurality of terminal devices 30 connected to the water outlet end of the heat pump unit 10 and arranged in parallel, a water tank 40 connecting the variable frequency water pump 20 and the terminal device 30, a detection unit arranged in the water path for detecting water flow or pipeline pressure, and a controller communicatively connected to the variable frequency water pump 20 and the detection unit, wherein the controller executes the adaptive adjustment control method of the variable frequency water pump 20 described in Embodiment 1 or Embodiment 2.

[0053] The inspection unit includes a first pressure gauge 51 and a flow meter 52 arranged on the main pipeline, and a second pressure gauge 53 arranged on the outlet pipeline of each terminal device 30 .

[0054] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for adaptively regulating and controlling a variable frequency water pump of a heat pump unit, characterized in that: The following steps are involved: S1. Obtaining the head-flow characteristic curve of the variable frequency water pump at each speed; S2. The variable frequency pump increases or decreases the frequency according to the number of user terminal devices turned on, and records the flow rate and head at each speed of the variable frequency pump, and fits the head-flow characteristic curve of the current pipeline; S3. Determine the required water flow rate according to the number of user terminal devices turned on, and obtain the optimal working point and the speed of the variable frequency pump under the current state; wherein the working point is the intersection of the head-flow characteristic curve of the pipeline and the head-flow characteristic curve of the variable frequency pump; S4. Based on the flow feedback from each terminal, after obtaining the optimal working point under the current state, check whether the current water flow of each terminal meets the rated flow of the terminal; if it meets, execute according to the current speed; if not, adjust the frequency until it meets.

2. The heat supply pump unit variable frequency water pump adaptive regulation control method according to claim 1 is characterized in that: In step S1, the head-flow characteristic curve of the variable frequency water pump at each speed is obtained according to the data provided by the variable frequency water pump manufacturer or through testing; the real-time flow of the pipeline is monitored by the flow feedback function of the variable frequency water pump or by setting a flow meter at the outlet of the variable frequency water pump; the real-time head at the outlet of the variable frequency water pump is monitored by setting a pressure gauge at the outlet of the variable frequency water pump.

3. The adaptive regulation and control method of the variable frequency water pump of the heat pump unit according to claim 1 is characterized in that: In step S2, the variable frequency water pump starts and increases the frequency to make the real-time flow rate Q 实 Reach the minimum flow rate Q of the unit min If Q 实 ±ΔQ=Q min , the unit runs stably for the preset time at the minimum flow rate; If Q 实 ±ΔQ is greater or less than Q min After running for a preset time, check again. If multiple checks are not satisfied, stop the machine to troubleshoot the fault; where ΔQ is the set allowable fluctuation range of water flow.

4. The heat supply pump unit variable frequency water pump adaptive regulation control method according to claim 3, characterized in that: In step S2, it also includes determining the speed adjustment range of the variable frequency water pump of the current user, assuming that the speed adjustment range of the variable frequency water pump is R1~Rn: if the minimum flow speed r min ≤R1, then the current user's variable frequency pump speed adjustment range is R1~Rn; if the minimum flow speed r min >R1, then the current user's variable frequency water pump speed adjustment range is r min ~Rn; the speed adjustment range is divided into three speed intervals, the first speed interval is r min / R1~(R1+ΔR), the second speed range is (R1+ΔR)~(R1+2ΔR), and the third speed range is (R1+2ΔR)~Rn; among which, ΔR=(Rn~R1) / 3.

5. The heat pump unit variable frequency water pump adaptive regulation control method according to claim 4, characterized in that: According to the rated capacity of the unit, calculate the rated water flow, set 60% of the rated water flow of the unit as the minimum flow of the unit, and the frequency corresponding to the minimum flow is the minimum flow speed r of the unit. min .

6. The heat pump unit variable frequency water pump adaptive regulation control method according to claim 4, characterized in that: The step S2 specifically includes: If the number of user terminal devices turned on n=1, the speed of the variable frequency pump changes from r min / R1, Nr rises every t seconds, and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed; If the number of user terminal devices turned on is n=2, the speed of the variable frequency water pump increases by Nr every t seconds from (R1+ΔR), and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed; If the number of user terminal devices turned on is n=3, the speed of the variable frequency water pump increases by Nr every t seconds from (R1+2ΔR), and the flow rate and head at each speed are recorded; after running for a preset time, the head-flow characteristic curve of the current pipeline is fitted through the working points at each speed.

7. The heat pump unit variable frequency water pump adaptive regulation control method according to claim 6, characterized in that: In step S2: If the number of user terminal devices turned on n=1, the maximum water flow value Q1 detected by the variable frequency water pump in the current speed range max <Q 总 , Q 总 is the total water flow required by the current water system, the variable frequency water pump speed is adjusted to the next speed range; if the minimum water flow value Q1 is detected min >Q 总 , then according to the minimum flow speed r min Run; when the detected water flow value Q1=Q 总 , according to the working points of each speed in the speed range, the head-flow characteristic curve of the current pipeline is fitted again; If the number of user terminal devices turned on n=2, the maximum water flow value detected by the variable frequency water pump in the current speed range is Q2 max <Q 总 , the variable frequency pump speed will be adjusted to the next speed range; if the minimum water flow value Q2 is detected min >Q 总 , the variable frequency water pump speed is adjusted to the next speed range; when the detected water flow value Q2=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the current pipeline is fitted again; If the number of user terminal devices turned on n=3, the maximum water flow value detected by the variable frequency water pump in the current speed range is Q3 max <Q 总 , it runs at the maximum speed; if the minimum water flow value detected is Q3 min >Q 总 , the variable frequency water pump speed is adjusted to the next speed range; when the detected water flow value Q3=Q 总 , according to the working points of each speed in the interval, the head-flow characteristic curve of the current pipeline is fitted again.

8. The heat pump unit variable frequency water pump adaptive regulation control method according to claim 7, characterized in that: In step S3, the rated water flow required at each terminal is Q 末 When the user turns on a terminal device, the system water flow is slightly greater than Q 末 , use Q' 末 express; If the number of user terminal devices turned on n=1, Q 总 =Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on is n=2, Q 总 =2Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the water pump needs to provide, and get the optimal speed of the water pump; If the number of user terminal devices turned on n=3, Q 总 =3Q' 末 , through the head-flow characteristic curve of the current pipeline and the total water flow Q required by the current water system 总 , get the current pipeline pressure loss, that is, the minimum head that the pump needs to provide, and get the optimal speed of the pump.

9. The heat pump unit variable frequency water pump adaptive regulation control method according to claim 8, characterized in that: In step S4, the flow rate Q of the opened terminal device is detected 检 , check the flow Q of each opened terminal device 检 Whether it meets the rated flow rate Q of the terminal equipment 末 , if Q 检 ≥Q 末 , it runs at the current speed; if Q 检 <Q 末 , then increase the speed of the variable frequency water pump until Q 检 ≥Q 末 .

10. A heat pump unit variable frequency water pump adaptive regulation control system, comprising a heat pump unit, a variable frequency water pump connected to the water inlet of the heat pump unit, a plurality of terminal devices connected to the water outlet of the heat pump unit and arranged in parallel, a water tank connecting the variable frequency water pump and the terminal devices, a detection unit arranged in the water channel for detecting water flow or pipeline pressure, and a controller connected to the variable frequency water pump and the detection unit in communication, characterized in that: The controller executes the variable frequency water pump adaptive adjustment control method according to any one of claims 1 to 9.

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