Multi-heat-source staged buffer heat supply device for water source heat pump

Abstract

The utility model belongs to water source heat pump heating system supporting equipment technical field discloses a kind of for the multi-heat source grading buffer heating device of water source heat pump, the device includes at least two parallel waste heat source input circuit, high temperature, medium temperature, low temperature three-level mother tube, installation elevation gradually reduces three-stage buffer tank, medium temperature buffer tank forced homogenization loop, three-way output branch with regulating valve, mixed output main and PLC control cabinet.The utility model can realize the source head grading flow guide of multiple fluctuation industrial waste heat, cascade buffer storage, active temperature homogenization and closed-loop proportional deployment, solve the problem that existing technology waste heat mixed flow loss is big, output water temperature fluctuation is big, improve waste heat utilization efficiency, guarantee water source heat pump unit stable operation.

Description

Technical Field

[0001] This utility model belongs to the technical field of supporting equipment for water source heat pump heating systems, specifically relating to a multi-heat source graded buffer heating device for water source heat pumps. Background Technology

[0002] Industrial processes such as cooking, condensation, heat exchange, and cooling continuously discharge large amounts of process water with low-temperature waste heat. This type of waste heat is large in total and has high recovery value. Using it as the heat source input of a water source heat pump unit can achieve efficient utilization of waste heat through the temperature increase and efficiency enhancement of the heat pump, thereby significantly reducing the energy consumption and carbon emissions of the heating system.

[0003] Taking the liquor brewing industry as an example, the temperature of the condensate discharged from the distillation section can reach 70℃~90℃, and the temperature of the cooling water discharged from the saccharification, fermentation and other sections is generally in the range of 30℃~60℃. The drainage time of different sections is not synchronized, and the instantaneous flow rate of a single water source fluctuates greatly. If this fluctuating waste heat is directly connected to a conventional water source heat pump system, it will cause the inlet temperature of the heat pump heat source side to fluctuate greatly, exceeding the unit's allowable ±2℃ stable water intake range, which will lead to abnormal evaporation pressure or condensation pressure of the unit, compressor overload, and even trigger high pressure and low pressure protection shutdown, seriously affecting the continuous and stable operation of the heating system.

[0004] In existing technologies, the conventional solution to this problem is to first collect multiple waste heat sources into a common main pipe, and then send them to a single buffer tank for natural mixing and homogenization before outputting them to the heat pump unit. This solution has the following drawbacks: First, high-grade waste heat suffers significant irreversible loss. Waste heat of different temperature levels mixes indiscriminately at the front-end main pipe. According to thermodynamic principles, the usable value of heat is positively correlated with temperature. Premature mixing of high-temperature and low-temperature waste heat leads to the dilution of high-grade heat by the low-temperature water, resulting in irreversible loss of usable value and reduced waste heat utilization efficiency. Second, the temperature homogenization capacity is insufficient and the response speed is slow. A single buffer tank relies solely on natural convection for temperature homogenization. For large-capacity tanks of tens of cubic meters commonly used in engineering, the time for complete homogenization by natural convection is typically over 60 minutes, which cannot cope with the second- or minute-level temperature changes in industrial waste heat. The problems are as follows: First, the output water temperature fluctuates greatly, failing to meet the stable water intake requirements of the water source heat pump unit. Second, the system has poor adaptability and fault tolerance, lacking a graded isolation and tiered volume buffer structure, making it unable to cope with extreme conditions such as short-term large flow impacts from multiple water sources and synchronous flow interruptions, easily leading to problems such as overflow, cross-contamination, and backflow. At the same time, a single water tank cannot simultaneously meet the dual requirements of preserving high-grade waste heat and buffering large-volume flow. Third, the output temperature control accuracy is low. Existing solutions mostly use a single water tank for unified water output, which can only achieve coarse temperature adjustment through auxiliary heating or cold water replenishment. It cannot achieve precise temperature adjustment by mixing different grades of waste heat in proportion, nor can it prioritize the use of high-grade waste heat, further exacerbating energy waste. Summary of the Invention

[0005] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:

[0006] A multi-heat-source staged buffer heating device for a water source heat pump includes: at least two parallel waste heat source input circuits, each equipped with a temperature sensor, a flow meter, an inlet check valve, and a one-inlet-three-outlet distribution mechanism; the three outlets of the one-inlet-three-outlet distribution mechanism are respectively connected to a high-temperature main pipe, a medium-temperature main pipe, and a low-temperature main pipe; the high-temperature main pipe is connected to a high-temperature buffer tank, the medium-temperature main pipe is connected to a medium-temperature buffer tank, and the low-temperature main pipe is connected to a low-temperature buffer tank; the installation elevations of the high-temperature buffer tank, the medium-temperature buffer tank, and the low-temperature buffer tank decrease sequentially; a first overflow channel is provided between the high-temperature buffer tank and the medium-temperature buffer tank, and between the medium-temperature buffer tank and the low-temperature buffer tank... A second overflow channel is provided. The external part of the medium-temperature buffer tank is equipped with a homogenization loop including a water inlet pipe, a variable frequency circulating water pump, and a return water pipe. The high-temperature buffer tank, medium-temperature buffer tank, and low-temperature buffer tank are all equipped with tank temperature sensors, and the medium-temperature buffer tank is also equipped with a liquid level sensor. The high-temperature buffer tank is connected to the high-temperature output branch, the medium-temperature buffer tank is connected to the medium-temperature output branch, and the low-temperature buffer tank is connected to the low-temperature output branch. The high-temperature output branch, the medium-temperature output branch, and the low-temperature output branch are all equipped with electric regulating valves and outlet check valves. The high-temperature output branch, the medium-temperature output branch, and the low-temperature output branch all converge into a mixed output main pipe equipped with a main water supply pump and an end temperature sensor.

[0007] It also includes a PLC control cabinet connected to temperature sensors, flow meters, a one-in-three-out distribution mechanism, tank temperature sensors, liquid level sensors, variable frequency circulating water pumps, electric regulating valves, a main water supply pump, and terminal temperature sensors. The PLC control cabinet is used to control the corresponding one-in-three-out distribution mechanism to introduce the waste heat source into the corresponding main pipe according to the inlet temperature and instantaneous flow of each waste heat source input circuit, and to adjust the opening of the electric regulating valve on each output branch according to the detection values ​​of the terminal temperature sensor and each tank temperature sensor, so as to output the mixed water.

[0008] Compared with the prior art, this utility model has the following advantages and beneficial effects: By using at least two parallel waste heat source input circuits, coupled with a temperature sensor, flow meter, inlet check valve, and a one-in-three-out distribution mechanism sequentially arranged on the circuit, and a high-temperature main pipe, a medium-temperature main pipe, and a low-temperature main pipe respectively connected to the three outlets of the distribution mechanism, it can be implemented in a PLC. Under the control of the control cabinet, based on the real-time temperature and instantaneous flow rate of each incoming water source, waste heat of different grades is diverted at the source to the corresponding temperature-grade main pipe. This avoids the dilution of high-grade heat and irreversible loss of calorific value caused by premature mixing of waste heat of different temperature grades. At the same time, the inlet check valve effectively prevents cross-flow and backflow caused by pressure differences between different waste heat source input circuits, ensuring the reliability of the front-end graded diversion. By connecting to the three-stage main pipe and installing high-temperature buffer tanks, medium-temperature buffer tanks, and low-temperature buffer tanks with progressively decreasing elevations, along with the first overflow channel between the high-temperature and medium-temperature buffer tanks and the second overflow channel between the medium-temperature and low-temperature buffer tanks, a tiered graded storage structure is formed. This achieves independent storage of waste heat of different grades, maximizing the preservation and utilization of high-grade waste heat, and also utilizes the elevation difference between the tanks to achieve... The gravity-fed recovery of overflow water avoids waste of waste heat resources. Simultaneously, the three-stage buffer structure effectively absorbs flow fluctuations from multiple incoming water sources, significantly improving the system's adaptability to complex water conditions. Furthermore, a forced homogenization loop consisting of an inlet pipe, a variable-frequency circulating pump, and a return pipe is installed outside the medium-temperature buffer tank. This actively drives the circulation of water within the tank, significantly accelerating temperature homogenization and eliminating localized hot and cold spots. This provides a stable, uniform water source for subsequent proportional adjustments, further reducing fluctuations in the output water temperature. Through high-temperature, medium-temperature, and low-temperature output branches connected to the three buffer tanks, along with electric regulating valves and outlet check valves on each branch, and a main output pipe containing a central water supply pump and end-point temperature sensors, the system can be controlled via PLC. Under the coordinated control of the control cabinet, the opening of the electric regulating valves of each output branch is precisely adjusted by combining the real-time detection values ​​of the terminal temperature sensor and the temperature sensors of each tank. This achieves closed-loop proportional mixing output of water of different grades. The outlet check valve can effectively prevent cross-flow and backflow between different branches, ensuring the accuracy and stability of temperature control. Finally, the PLC control cabinet links all detection and execution components of the entire process, from front-end graded flow guidance, mid-stage buffering and homogenization, to terminal proportional temperature control, forming a complete adaptive closed-loop control system. This system can effectively cope with complex operating conditions such as large fluctuations in temperature and flow rate of multiple waste heat sources, and even short-term flow interruptions. It provides the downstream water source heat pump unit with stable temperature and controllable quality heat source water, effectively preventing the heat pump unit from triggering high-pressure, low-pressure, or overload protection shutdowns due to fluctuations in inlet water temperature. While significantly improving the efficiency of industrial waste heat recovery and utilization, it also significantly improves the operational stability and continuous operation capability of the water source heat pump heating system. Attached Figure Description

[0009] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0010] Figure 1 This is a schematic diagram of the structure of a multi-heat source graded buffer heating device for a water source heat pump, provided as an embodiment of the present invention.

[0011] The attached diagram shows the markings and corresponding component names:

[0012] 1-Temperature sensor, 2-Flow meter, 3-Inlet check valve, 4-One-in-three-outlet distribution mechanism, 5-High temperature main pipe, 6-Medium temperature main pipe, 7-Low temperature main pipe, 8-High temperature buffer tank, 9-Medium temperature buffer tank, 10-Low temperature buffer tank, 11-First overflow channel, 12-Second overflow channel, 13-Water inlet pipe, 14-Variable frequency circulating water pump, 15-Return water pipe, 16-Tank temperature sensor, 17-Electric regulating valve, 18-Outlet check valve, 19-Main water supply pump, 20-End temperature sensor, 21-PLC control cabinet, 22-Mixed output main pipe. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with embodiments. The illustrative embodiments and descriptions of this utility model are for explanation only and are not intended to limit the scope of the utility model. The embodiments described below are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0014] In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other embodiments, well-known structures, materials, or methods are not specifically described to avoid obscuring the present invention. Unless otherwise specified, the materials, instruments, and reagents used in the following embodiments are commercially available. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0015] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0016] Example: This invention provides a multi-heat-source staged buffer heating device for water source heat pumps, providing integrated heating for multiple fluctuating industrial waste heat sources. The device includes: staged source collection, tiered volumetric buffering, active homogenization, and closed-loop proportional distribution. It addresses the problems of insufficient front-end mixing of multiple waste heat sources, inadequate temperature homogenization, large output temperature fluctuations, and weak system fault tolerance in existing technologies. This device is suitable for industrial scenarios with multiple intermittent, highly fluctuating process cooling water waste heat emissions, such as liquor brewing, food processing, pharmaceuticals, chemicals, and textile printing and dyeing. It can efficiently recover industrial waste heat while providing stable temperature and controllable quality inlet water to the water source heat pump unit, ensuring long-term stable and efficient operation of the water source heat pump system.

[0017] This embodiment describes a multi-heat-source graded buffer heating device for a water source heat pump, comprising: a multi-path waste heat source access module, a graded main pipe module, a cascade buffer module, a proportional manifold output module, and an electronic control linkage module. Each module is connected sequentially along the fluid flow direction and operates collaboratively under the control of the electronic control linkage module, achieving source grading, cascade storage, active homogenization, and precise distribution output of multiple fluctuating waste heat sources. The following is combined with... Figure 1 The composition and connection relationships of each module are explained below:

[0018] 1. Multi-channel waste heat source access module

[0019] The multi-channel waste heat source access module is the front-end inlet of the entire device. It is used to perform real-time status detection and graded diversion of each independent industrial waste heat water source, so as to avoid the mixing of waste heat of different grades at the front end and prevent high-grade heat from being diluted by low-temperature water.

[0020] The multi-channel waste heat source access module includes at least two parallel waste heat source input circuits. The number of waste heat source input circuits matches the number of waste heat emission sections in the industrial site. Each waste heat source input circuit corresponds to an independent industrial waste heat emission section. The waste heat source input circuits are independent of each other and not directly connected, preventing premature mixing of waste heat from different sections. In this embodiment, the multi-channel waste heat source access module includes two parallel waste heat source input circuits, corresponding to two waste heat emission sections, and each waste heat source input circuit is independent of the others.

[0021] Each waste heat source input circuit is equipped with a temperature sensor 1, a flow meter 2, an inlet check valve 3, and a one-in-three-out distribution mechanism 4, which are arranged sequentially along the fluid flow direction to detect and classify the incoming water.

[0022] The temperature sensor 1 is a PT1000 platinum resistance temperature sensor with a measurement accuracy of no less than ±0.2℃ and a sampling frequency of no less than 1Hz. It can collect the instantaneous temperature of the incoming water in the corresponding waste heat source input circuit in real time and upload the temperature signal to the PLC control cabinet 21 as the basis for judging the waste heat temperature classification of that circuit. In this embodiment, the temperature sensor 1 is a PT1000 sensor with a measurement accuracy of ±0.1℃ and a sampling frequency of 2Hz to ensure the accuracy and real-time performance of the detection.

[0023] The flow meter 2 is an electromagnetic flow meter 2 or a vortex flow meter 2 with a measurement accuracy of not less than 0.5. It can collect the instantaneous flow rate and cumulative flow rate of the incoming water in the corresponding waste heat source input circuit in real time, and upload the flow signal to the PLC control cabinet 21 to determine whether the waste heat source is in an effective incoming water state.

[0024] The inlet check valve 3 is a silent, slow-closing check valve with a nominal pressure matching the design pressure of the corresponding waste heat source input circuit. Its opening pressure is no greater than 0.03 MPa. The inlet check valve 3 is installed downstream of the flow meter 2 and upstream of the one-in-three-out distribution mechanism 4. It prevents backflow and cross-contamination of media between different waste heat source input circuits due to pressure differences, and also avoids backflow of media from the downstream header pipe to the upstream process section, ensuring the safe operation of the upstream process equipment. In this embodiment, a DN80 silent, slow-closing check valve with a nominal pressure of 1.0 MPa is selected.

[0025] The one-in-three-out distribution mechanism 4 includes one inlet and three independent outlets. The three outlets are interlocked, allowing only one outlet to be fully open at any given time, while the other two are fully closed, preventing cross-flow between main pipes of different temperature ratings. The one-in-three-out distribution mechanism 4 can employ an integrated three-position four-way electric distribution valve with a valve body made of ductile iron or stainless steel, a sealing rating of at least IP67, and a response time of no more than 3 seconds. Alternatively, it can consist of three electric valves of the same specification, interlocked to form an equivalent one-in-three-out distribution valve group. In this embodiment, three DN80 electric on / off valves are selected to form the equivalent one-in-three-out distribution valve group. The inlets of the three electric on / off valves are connected to the outlets of their respective circuits, and the outlets of the three electric on / off valves are respectively connected to the subsequent high-temperature main pipe 5, medium-temperature main pipe 6, and low-temperature main pipe 7. By interlocking the three electric on / off valves, only one valve is allowed to open at a time, preventing cross-flow between different main pipes.

[0026] To achieve graded flow diversion, a high-temperature threshold T1, a medium-temperature threshold T2 (T1 > T2), and an effective flow rate threshold Q can be preset in the control logic. min And the status confirmation time t0. In this embodiment, based on the temperature distribution of waste heat from liquor brewing, a preset high-temperature threshold T1=45℃, a medium-temperature threshold T2=30℃, and an effective flow rate threshold Q are defined. min =2m³ / h and status confirmation time t0=5s. During device operation, the inlet water temperature T and instantaneous flow rate Q of each waste heat source input loop are collected in real time. When the instantaneous flow rate Q ≥ the effective flow rate threshold Q... min When the duration of the incoming water temperature T ≥ high temperature threshold T1 ≥ state confirmation time t0, the incoming water in the waste heat source input circuit is determined to be effective high temperature incoming water. The one-in-three-out distribution mechanism 4 of the waste heat source input circuit is controlled to switch to the outlet corresponding to the high temperature header 5, and the waste heat of the waste heat source input circuit is introduced into the high temperature header 5; when the instantaneous flow rate Q ≥ effective flow rate threshold Q min When the duration of the intermediate temperature threshold T2 < inlet water temperature T < high temperature threshold T1 is greater than or equal to the state confirmation time t0, the inlet water of the waste heat source input circuit is determined to be effective intermediate temperature inlet water. The one-inlet-three-outlet distribution mechanism 4 is controlled to switch to the outlet corresponding to the intermediate temperature header 6, and the waste heat of the waste heat source input circuit is introduced into the intermediate temperature header 6; when the instantaneous flow rate Q ≥ effective flow rate threshold Q min When the duration of the incoming water temperature T ≤ medium temperature threshold T2 is ≥ state confirmation time t0, the incoming water in the waste heat source input circuit is determined to be effective low-temperature incoming water. The one-in-three-outlet distribution mechanism 4 is controlled to switch to the outlet corresponding to the low-temperature header 7, and the waste heat of the waste heat source input circuit is introduced into the low-temperature header 7; when the instantaneous flow rate Q < effective flow rate threshold Q min If the incoming water in the waste heat source input circuit is deemed invalid, all outlets of the one-in-three-outlet distribution mechanism 4 will be closed to prevent backflow of the medium in the main pipe. By setting a status confirmation time t0, the frequent switching of the one-in-three-outlet distribution mechanism 4 caused by fluctuations in the incoming water temperature near the threshold critical point can be effectively avoided, thus extending the service life of the equipment and improving the stability of system operation.

[0027] Both the interlock control logic and the graded flow diversion control logic described above can be implemented using the standard control unit of the existing PLC control cabinet 21, or they can be implemented using a hard-wired control circuit consisting of an existing temperature controller (or temperature sensor 1), flow switch (or flow relay), time relay, intermediate relay, and valve interlock drive circuit. Their control principles are all based on existing conventional control methods that utilize temperature threshold comparison, effective flow determination, hysteresis anti-jitter, delay confirmation, and valve position interlock drive. Specifically, the control system receives temperature and flow signals from each waste heat source input circuit, performs threshold comparison on the temperature signals, determines the effective incoming water flow on the flow signals, and outputs valve switching signals in conjunction with delay confirmation, hysteresis anti-jitter, and valve position interlock logic. This achieves stable control of the one-inlet, three-outlet distribution mechanism 4, avoiding frequent switching under threshold critical conditions and improving system operational stability.

[0028] 2. Hierarchical main pipe module

[0029] Different grades of waste heat after front-end grading and diversion need to be sent to the subsequent storage stage through independent conveying channels to avoid mixing during the conveying process and reduce heat loss during the conveying process. Therefore, a graded main pipe module is set in this device to receive the front-end multi-channel waste heat source access module and the subsequent cascade buffer module.

[0030] The graded main pipe module comprises multiple independent and unconnected main pipes, with each main pipe corresponding to one outlet in the multi-source waste heat source access module. In this embodiment, the graded main pipe module includes three main pipes: a high-temperature main pipe 5, a medium-temperature main pipe 6, and a low-temperature main pipe 7. The three outlets of the aforementioned one-in-three-out distribution mechanism 4 are respectively connected to the high-temperature main pipe 5, the medium-temperature main pipe 6, and the low-temperature main pipe 7, enabling independent transport of waste heat at different temperature levels. All three main pipes can be made of seamless steel pipes, with the outer wall of the seamless steel pipes covered with a polyurethane insulation layer to form an insulated transport structure. A protective outer shell is provided outside the insulation layer. The nominal diameter of the main pipes is calculated and determined based on the maximum design flow rate of the corresponding section. Furthermore, the three main pipes are laid in the same direction to ensure that the friction resistance along the path from each waste heat source input circuit to the corresponding buffer tank is consistent, avoiding pressure interference between different circuits.

[0031] 3. Cascade buffer module

[0032] Different grades of waste heat, which are independently transported by the graded main pipe module, need to be stored in stages. At the same time, temperature homogenization and flow fluctuation buffering are achieved to provide a stable water source for subsequent temperature regulation. Therefore, the high-grade waste heat is preserved, the medium-temperature water body is actively homogenized, and the large-volume flow buffer is achieved through the cascade buffer module.

[0033] The cascade buffer module includes a high-temperature buffer tank 8, a medium-temperature buffer tank 9, and a low-temperature buffer tank 10. All three are vertical, pressure-bearing, insulated storage tanks (the outer wall can be covered with a polyurethane insulation layer). Their installation elevations decrease sequentially; that is, the lowest safe liquid level of the high-temperature buffer tank 8 is higher than the highest overflow liquid level of the medium-temperature buffer tank 9, and the lowest safe liquid level of the medium-temperature buffer tank 9 is higher than the highest overflow liquid level of the low-temperature buffer tank 10. The purpose of this elevation difference is to provide gravity-fed overflow for the cascade, eliminating the need for an additional transfer pump to allow overflow water from the previous buffer tank to flow to the next, thus reducing energy consumption. The high-temperature buffer tank 8 is connected to the high-temperature main pipe 5, the medium-temperature buffer tank 9 is connected to the medium-temperature main pipe 6, and the low-temperature buffer tank 10 is connected to the low-temperature main pipe 7, enabling independent storage of waste heat of different grades. For example, the installation reference elevation of the high-temperature buffer tank 8 is 1.5m higher than that of the medium-temperature buffer tank 9, and the installation reference elevation of the medium-temperature buffer tank 9 is 1.5m higher than that of the low-temperature buffer tank 10, providing sufficient gravity flow conditions for the cascade overflow.

[0034] To fully recover the overflow water from the previous buffer tank and prevent backflow of the medium into the next buffer tank, a first overflow channel 11 is provided between the high-temperature buffer tank 8 and the medium-temperature buffer tank 9. The inlet of the first overflow channel 11 is connected to the overflow port of the high-temperature buffer tank 8, and the overflow port is located at the highest safe liquid level on the side wall of the high-temperature buffer tank 8. The outlet of the first overflow channel 11 is connected to the return port of the medium-temperature buffer tank 9. A first one-way check valve is provided on the first overflow channel 11. This valve is a vertical check valve that only allows the medium to flow unidirectionally from the high-temperature buffer tank 8 to the medium-temperature buffer tank 9. Similarly, a second overflow channel 12 is provided between the medium-temperature buffer tank 9 and the low-temperature buffer tank 10. The inlet of the second overflow channel 12 is connected to the overflow port of the medium-temperature buffer tank 9, and the overflow port is located on the side wall of the medium-temperature buffer tank 9 at the position corresponding to the highest safe liquid level. The outlet of the second overflow channel 12 is connected to the return port of the low-temperature buffer tank 10. A second one-way check valve is provided on the second overflow channel 12, which only allows liquid to flow unidirectionally from the medium-temperature buffer tank 9 to the low-temperature buffer tank 10. In this embodiment, both the first overflow channel 11 and the second overflow channel 12 use DN80 pipelines and are equipped with vertical check valves of corresponding specifications to ensure smooth overflow while preventing backflow.

[0035] To monitor the operating status of the buffer tanks in real time, high-temperature buffer tank 8, medium-temperature buffer tank 9, and low-temperature buffer tank 10 are each equipped with a tank temperature sensor 16, which can collect the water temperature in the corresponding buffer tank in real time. The medium-temperature buffer tank 9 is also equipped with a level sensor, which is a submersible hydrostatic level gauge or a radar level gauge with a measurement accuracy of not less than 0.5 class, and can collect the level signal in the medium-temperature buffer tank 9 in real time. In this embodiment, the tank temperature sensor 16 on the medium-temperature buffer tank 9 is a multi-point temperature measurement component, including three temperature measurement points evenly arranged along the height of the tank, respectively set at 10% (lower), 50% (middle), and 90% (upper) of the effective height of the tank. It can collect the water temperature at different heights in the tank in real time. Therefore, the temperature distribution of the water in the tank is determined based on the temperature difference between the upper and lower temperature measurement points, thereby adjusting the operating status of the subsequent homogenization loop. The level sensor uses a 0.5 class submersible hydrostatic level gauge to ensure the accuracy of level detection.

[0036] Furthermore, the high-temperature buffer tank 8 is used to store high-grade waste heat. Therefore, the inlet is located at the center of the upper end cap on the top of the tank, and the outlet is located on the upper part of the side wall of the tank, corresponding to 80% to 90% of the effective height of the tank. This inlet placement utilizes the characteristic that high-temperature water has a lower density than low-temperature water, allowing the incoming high-temperature water to naturally form a stable high-temperature water layer on the upper part of the tank. During discharge, the upper high-temperature water is preferentially extracted, structurally reducing the impact of low-temperature water inside the tank on the output water temperature, thus achieving the preservation and storage of high-grade waste heat. Simultaneously, to cope with situations where there is no effective high-temperature water supply from the front end, an electric heater is also installed inside the high-temperature buffer tank 8. The electric heater uses a U-shaped stainless steel electric heating tube, and the total power is calculated and determined according to the system's minimum heating requirements. The electric heater is installed at the bottom of the tank, with its lowest installation elevation higher than the tank's lowest safe liquid level elevation to prevent the electric heater from burning dry above the liquid surface.

[0037] It should be noted that the start / stop status and output power of the electric heater can be achieved using existing control methods. Specifically, the start / stop status of the electric heater can be jointly controlled based on the temperature and liquid level signals within the high-temperature buffer tank 8: when the tank temperature is lower than the preset minimum protection temperature and the liquid level is higher than the minimum protection level, the electric heater is activated; when the tank temperature rises to the preset stop temperature, the electric heater is deactivated; when the liquid level is lower than the minimum protection level, the electric heater is deactivated or its activation is prohibited to prevent dry burning. Furthermore, the output power of the electric heater can be adjusted in stages or continuously based on the tank temperature signal. Specifically, existing temperature controllers, SCR power controllers, or PLC analog output control modules can be used to adjust the input power of the electric heater according to the deviation between the tank temperature and the target temperature. In another embodiment, the heating drive module can also be controlled by combining the liquid level signal and the temperature signal, where the liquid level signal is mainly used for low-level interlock protection, and the temperature signal is mainly used for power regulation and start / stop control.

[0038] The intermediate-temperature buffer tank 9 is used to store medium-grade waste heat and improves homogenization efficiency through active homogenization, providing a stable water source with uniform temperature for subsequent proportional temperature control. Therefore, a homogenization loop is provided outside the intermediate-temperature buffer tank 9, which includes a water inlet pipe 13, a variable frequency circulating water pump 14, and a return water pipe 15. The inlet of the water pipe 13 is connected to the outlet at the bottom of the medium-temperature buffer tank 9, and the outlet of the water pipe 13 is connected to the inlet of the variable frequency circulating water pump 14, which is used to draw out the low-temperature water at the bottom of the medium-temperature buffer tank 9. The variable frequency circulating water pump 14 is a horizontal centrifugal variable frequency pump with a frequency adjustment range of 0~50Hz. The head and flow rate are calculated and determined according to the effective volume of the medium-temperature buffer tank 9, which is used to provide power for water circulation in the medium-temperature buffer tank 9. The inlet of the return water pipe 15 is connected to the outlet of the variable frequency circulating water pump 14, and the outlet of the return water pipe 15 is connected to the return port on the side wall of the medium-temperature buffer tank 9, which is used to send the pressurized water back into the medium-temperature buffer tank 9.

[0039] To further improve the homogenization effect and avoid overflow caused by the return water impacting the liquid surface, the inlet of the return water pipe 15 is arranged tangentially relative to the inner wall of the medium-temperature buffer tank 9, and the axis of the return water pipe 15 is inclined downwards at 15° to 30° relative to the horizontal plane. Its inlet position corresponds to the lower part of the medium-temperature buffer tank 9 (such as 30% to 40% of the effective height of the medium-temperature buffer tank 9). The purpose of arranging the return water pipe 15 in this way is to form a stable rotating flow field in the tank through tangential water inlet, which drives the upper and lower layers of water in the tank to generate convection, thereby improving the efficiency of temperature homogenization. At the same time, the downward inclined return water direction and the inlet position in the lower part of the medium-temperature buffer tank 9 allow the return water to act directly on the low-temperature water in the lower part of the tank, avoiding the liquid surface turbulence caused by the return water directly impacting the liquid surface and reducing the risk of overflow.

[0040] To achieve adaptive control of the homogenization loop, a temperature non-uniformity threshold ΔT can be set in the control logic. max The overflow warning level H1 and the maximum safe level H2 are set in the control logic of this embodiment, and a temperature non-uniformity threshold ΔT is set in the control logic. max =2℃. During operation, the temperature of the upper, middle, and lower measuring points of the intermediate-temperature buffer tank 9 is collected in real time. The temperature difference ΔT between the upper and lower measuring points is calculated, and the real-time liquid level H inside the tank is also collected. When the temperature difference ΔT ≥ the temperature non-uniformity threshold ΔT... maxWhen the real-time liquid level H < overflow warning level H1, the variable frequency circulating water pump 14 is started, and its operating frequency is linearly adjusted according to the temperature difference ΔT. The larger the temperature difference ΔT, the higher the operating frequency of the variable frequency circulating water pump 14, the larger the circulation flow, and the stronger the homogenization effect. When the overflow warning level H1 ≤ real-time liquid level H < maximum safe liquid level H2, the maximum operating frequency of the variable frequency circulating water pump 14 is limited to below the preset safe frequency threshold, reducing the circulation flow, minimizing the disturbance of the return water to the liquid surface, and preventing accidental overflow. When the real-time liquid level H ≥ maximum safe liquid level H2, the variable frequency circulating water pump 14 is stopped to eliminate the disturbance of the return water to the liquid surface and ensure normal overflow of the overflow channel. Through the adaptive control of the homogenization loop, the temperature difference between the upper and lower layers in the medium-temperature buffer tank 9 can be effectively controlled, providing a stable medium-temperature water source for subsequent proportional temperature adjustment.

[0041] It should be noted that the adaptive control of the homogenization loop can be achieved using existing temperature difference controllers, standard control units of PLC control cabinet 21, and existing frequency converters. Its control principle is based on conventional control methods such as temperature difference judgment, variable frequency speed regulation, frequency upper limit limiting, and shutdown control. Specifically, when the temperature difference ΔT between different temperature measuring points in the intermediate temperature buffer tank 9 reaches a preset start-up threshold, the variable frequency circulating water pump 14 can be started. The PLC control cabinet 21, temperature difference controller, or other existing control output units output control signals according to a preset correspondence, causing the frequency converter to adjust the operating frequency of the variable frequency circulating water pump 14 according to the control signal. This preset correspondence can be linear, thus linearly adjusting the operating frequency of the variable frequency circulating water pump 14 based on the magnitude of the temperature difference ΔT. Furthermore, to prevent the variable frequency circulating water pump 14 from operating at excessively high speeds for extended periods, its maximum operating frequency can be limited to below a preset safe frequency threshold using the maximum output frequency parameter or upper limit frequency parameter of the existing frequency converter.

[0042] When the temperature difference ΔT drops below the preset stop threshold, the variable frequency circulating water pump 14 can be controlled to stop running. In one embodiment, an existing differential temperature controller can be used to directly output a pump stop signal. In another embodiment, the PLC can also send a stop command or cancel the frequency setting signal to the frequency converter directly after detecting that the temperature difference ΔT is lower than the preset stop threshold, so as to stop the variable frequency circulating water pump 14.

[0043] The cryogenic buffer tank 10 is used to store low-grade waste heat and to buffer the volumetric throughput and flow fluctuations of the entire device. Therefore, the inlet of the cryogenic buffer tank 10 is located at the center of the bottom of the tank, and the outlet of the cryogenic buffer tank 10 is located at the lower part of the side wall of the tank, corresponding to 20% to 30% of the effective height of the tank. This allows the cryogenic water to enter from the bottom of the tank and slowly fill from bottom to top, which can effectively reduce the impact of the incoming water on the liquid surface inside the tank and avoid liquid level detection errors caused by violent fluctuations in the liquid level. In addition, the outlet is located at the bottom of the tank, which can also ensure stable water output under low liquid level conditions.

[0044] To meet the flow buffering requirements of the entire system, the effective volume of the low-temperature buffer tank 10 must be greater than that of the medium-temperature buffer tank 9. The effective volume of the medium-temperature buffer tank 9 should not be less than that of the high-temperature buffer tank 8, and the effective volume of the low-temperature buffer tank 10 should not be less than the sum of the effective volumes of the high-temperature buffer tank 8 and the medium-temperature buffer tank 9. The principle behind this volume ratio is that the low-temperature buffer tank 10, as the final volume buffer unit of the entire system, needs to withstand the flow fluctuation impact of the entire system, including short-term large flow impacts from multiple upstream water sources, overflow water collection from the two upstream buffer tanks, and continuous water supply guarantee when upstream water flow is interrupted. This volume ratio can effectively absorb flow fluctuations, prevent system overflow, and extend the continuous heating time under flow interruption conditions.

[0045] In addition, to ensure the safe operation of the three buffer tanks, the tops of the high-temperature buffer tank 8, the medium-temperature buffer tank 9, and the low-temperature buffer tank 10 are all equipped with breather valves with flame-arresting function. The opening pressure of the breather valve is matched with the design pressure of the tank body to balance the pressure fluctuations in the gas phase space caused by the rise and fall of the liquid level and temperature changes, avoid the risk of positive pressure overpressure or negative pressure collapse of the tank body, and at the same time prevent the water in the tank from directly contacting the outside air, reducing heat loss and oxidation corrosion of the water.

[0046] In summary, the waste heat transported by the graded main pipe module enters the corresponding buffer tanks: the high-temperature water in the high-temperature buffer tank 8 forms a stable high-temperature water layer at the top and is preferentially output from the upper outlet of the high-temperature buffer tank 8 to maintain high-grade waste heat. When the liquid level in the high-temperature buffer tank 8 reaches the maximum safe level, the excess water flows by gravity into the medium-temperature buffer tank 9 through the first overflow channel 11, achieving full heat recovery; the water in the medium-temperature buffer tank 9 is rapidly homogenized through the homogenization loop. When the liquid level reaches the maximum safe level, the excess water flows by gravity into the low-temperature buffer tank 10 through the second overflow channel 12; the low-temperature buffer tank 10 collects the low-temperature incoming water and the overflow water from the previous two stages. The above volume ratio absorbs the flow fluctuations of the entire system, ensuring continuous water supply to the system.

[0047] 4. Proportional bus output module

[0048] Different grades of water, after being stored and homogenized by the cascade buffer module, need to be mixed proportionally to achieve precise control of the output water temperature, so as to provide a stable heat source water for the water source heat pump unit. Therefore, this device uses a proportional manifold output module to mix water of different grades to achieve high-precision control of the output temperature.

[0049] The proportional manifold output module includes a high-temperature output branch connected to the high-temperature buffer tank 8, a medium-temperature output branch connected to the medium-temperature buffer tank 9, and a low-temperature output branch connected to the low-temperature buffer tank 10. Each output branch is equipped with an electric regulating valve 17 and an outlet check valve 18 sequentially along the fluid flow direction. The downstream ends of the three output branches converge into the mixing output manifold 22. The electric regulating valve 17 can be an electric proportional regulating valve with equal percentage flow characteristics, a regulating accuracy of not less than 0.5%, and an adjustable ratio of not less than 100:1. It is used to continuously regulate the outlet flow of the corresponding branch to achieve proportional mixing of water at different temperatures. The outlet check valve 18 can be a silent, slow-closing check valve, installed downstream of the electric regulating valve 17. It is used to prevent the medium in the mixing output manifold 22 from flowing back into the buffer tank, and to avoid crossflow between different output branches due to pressure differences, ensuring the independent regulating performance of each branch.

[0050] To ensure uniform mixing and stable delivery of water of different grades, a static mixer, a main water supply pump 19, a terminal temperature sensor 20, and a pressure sensor are sequentially installed along the fluid flow direction on the mixing output main pipe 22. The static mixer can be an SK or SX type, used to thoroughly mix high-temperature, medium-temperature, and low-temperature water from different branches within a short distance, avoiding temperature detection errors caused by uneven mixing. The main water supply pump 19 can be a horizontal centrifugal variable frequency pump, used to provide power for transporting the mixed heat source water, pressurizing and delivering it to the heat source side inlet of the water source heat pump unit. Variable frequency adjustment can adapt to different inlet water flow requirements of the heat pump unit. The terminal temperature sensor 20 can be a PT1000 platinum resistance temperature sensor 1, with a measurement accuracy of not less than ±0.2℃ and a sampling frequency of not less than 1Hz, used to detect the actual temperature of the output water after mixing in real time, providing a basis for closed-loop temperature regulation.

[0051] To achieve stable control of the output water temperature, a target output temperature T can be preset in the control logic. s and temperature tolerance ΔT s During device operation, the actual output temperature T detected by the terminal temperature sensor 20 is collected in real time. outSimultaneously, the temperatures Ts of high-temperature buffer tank 8, Tz of medium-temperature buffer tank 9, and Td of low-temperature buffer tank 10 are collected, and a proportional-integral-derivative (PID) closed-loop control is employed. Specifically, the control strategy is as follows: when the actual output temperature T... out <Temperature of high-temperature buffer tank 8 Ts - Temperature tolerance ΔT> s When the high-temperature output branch electric regulating valve 17 is opened, the opening degree of the valve is increased first to improve the mixing ratio of high-temperature water and quickly increase the output temperature; when the opening degree of the high-temperature output branch electric regulating valve 17 reaches more than 90%, the actual output temperature T out Still less than the temperature of the high-temperature buffer tank 8 Ts - temperature allowable deviation ΔT s At this time, further increase the opening of the electric regulating valve 17 in the medium-temperature output branch to assist in increasing the output temperature; when the actual output temperature T out >High-temperature buffer tank 8 temperature Ts + allowable temperature deviation ΔT s When the high-temperature output branch electric regulating valve 17 is closed, the opening degree of the valve is reduced first to decrease the mixing ratio of high-temperature water and quickly reduce the output temperature; when the opening degree of the high-temperature output branch electric regulating valve 17 is closed to below 10%, the actual output temperature T out Still greater than the temperature of the high-temperature buffer tank (Ts) + allowable temperature deviation ΔT s At the same time, the opening of the electric regulating valve 17 in the medium-temperature output branch is reduced, while the opening of the electric regulating valve 17 in the low-temperature output branch is increased to help lower the output temperature. This regulation strategy prioritizes the use of high-grade high-temperature waste heat, minimizing its waste and improving energy efficiency. Simultaneously, through PID closed-loop regulation, the fluctuation range of the output water temperature can be controlled within ±ΔT. s Within this range, it meets the water inlet requirements of the water source heat pump unit.

[0052] It should be noted that the above-mentioned PID closed-loop regulation can be implemented using existing control methods. Its control principle is based on existing conventional closed-loop control methods that perform proportional, integral, and derivative calculations based on the deviation between the feedback quantity and the setpoint, and adjust the valve opening or actuator position according to the calculation results. Specifically, the existing temperature controller or the PID standard control unit of the PLC control cabinet 21 can be used. The actual temperature collected by the terminal temperature sensor 20 or the tank temperature sensor 16 is used as the feedback quantity, and the preset target temperature is used as the setpoint. The control signal is output according to the existing PID control method to control the electric regulating valve 17 to open, close, or maintain its position, thereby achieving closed-loop regulation of the mixed output temperature. Furthermore, when it is necessary to adjust the electric regulating valves 17 on multiple output branches sequentially, existing sequential control or split-range control methods can be used. That is, first, the first branch electric regulating valve 17 is controlled to operate within its corresponding control range. When the first branch reaches the preset opening limit or the corresponding control range limit, the second branch electric regulating valve 17 is then controlled to operate, and then the third branch electric regulating valve 17 is controlled to operate.

[0053] 5. Electrical control linkage module

[0054] To ensure safe operation and continuous heating under extreme conditions, the electrical control linkage module is also equipped with cascade overflow safety logic and backup heating logic to achieve safety protection and backup heating for the entire system.

[0055] The cascade overflow safety logic is used to prevent system overflow when a large flow rate impact occurs at the front end. Overflow warning levels, maximum safe levels, and over-high level warning values ​​can be set for the three buffer tanks in the control logic. During operation, for the high-temperature buffer tank 8, when the liquid level reaches the overflow warning level, the opening of the electric regulating valve 17 on the high-temperature output branch is increased first to increase the consumption rate of high-temperature water and lower the liquid level in the tank. If the liquid level continues to rise to the maximum safe level, the excess water automatically flows by gravity into the medium-temperature buffer tank 9 through the first overflow channel 11. For the medium-temperature buffer tank 9, when the liquid level reaches the overflow warning level, the operating frequency of the variable frequency circulating water pump 14 is reduced, and the opening of the electric regulating valve 17 on the medium-temperature output branch is increased to lower the liquid level in the tank. If the liquid level continues to rise to the maximum safe level, the excess water automatically flows by gravity into the low-temperature buffer tank 10 through the second overflow channel 12. For the cryogenic buffer tank 10, when the liquid level in the tank reaches the overflow warning level, the opening of the electric regulating valve 17 of the cryogenic output branch is increased to increase the consumption rate of cryogenic water; if the liquid level continues to rise to the ultra-high liquid level warning value, an audible and visual alarm signal is triggered, and an alarm signal is sent to the user's central control system to remind the operation and maintenance personnel to handle it in time and avoid system overflow.

[0056] The backup heating logic is used to maintain the system's continuous heating capacity in extreme conditions where there is no effective water supply from the upstream end. The backup temperature T can be set in the control logic.min and minimum protection level H min During operation, the flow signals of all waste heat source input loops are collected in real time. When the flow rate of all loops is lower than the effective flow rate threshold Q, the system will detect the flow rate. min If the duration exceeds the preset time, the system is determined to be in a state of no effective water supply; at this time, if the temperature inside the high-temperature buffer tank 8 is lower than the minimum protection temperature T... min The control cabinet starts the electric heater to provide auxiliary heating to the water in the high-temperature buffer tank 8; when the temperature in the high-temperature buffer tank 8 reaches T... min When the temperature deviation exceeds +△T (preset temperature deviation), the electric heater is stopped to maintain a stable temperature inside the tank; when the liquid level in the high-temperature buffer tank 8 falls below the minimum protection level H... min In case of emergency, the electric heater is forcibly stopped to prevent it from burning dry and being damaged, thus ensuring equipment safety.

[0057] It should be noted that:

[0058] (1) The cascade overflow safety logic can be implemented by using existing liquid level detection elements, liquid level alarm elements, relay interlock circuits or standard control units of PLC control cabinet 21 in conjunction with valves, circulating water pumps and other actuators. Its control principle belongs to the existing conventional control method based on liquid level signals for early warning, interlocking and actuator control. Specifically, when the liquid level of high temperature buffer tank 8 reaches the preset overflow warning level, an early warning signal can be output, and the electric regulating valve 17 on the high temperature output branch can be opened to give priority to the output of liquid in high temperature buffer tank 8; when the liquid level of high temperature buffer tank 8 continues to rise to the highest safe level, the excess liquid flows into medium temperature buffer tank 9 through the first overflow channel 11. When the liquid level of medium temperature buffer tank 9 reaches the preset overflow warning level, the variable frequency circulating water pump 14 outside medium temperature buffer tank 9 can be controlled to reduce the operating frequency or stop operation, thereby reducing the disturbance of liquid in the tank; when the liquid level of medium temperature buffer tank 9 continues to rise to the highest safe level, the excess liquid flows into low temperature buffer tank 10 through the second overflow channel 12. When the liquid level in the cryogenic buffer tank 10 reaches the preset high liquid level warning value, an alarm can be triggered, and the electric regulating valve 17 on the cryogenic output branch can be opened wider, thereby accelerating the liquid output from the cryogenic buffer tank 10.

[0059] (2) The guaranteed heating logic can be implemented using existing low-limit temperature control, differential start-stop control, low liquid level interlock cut-off control, and electric heating drive control loops. Its control principle belongs to the existing conventional control method based on temperature detection, liquid level protection, and auxiliary heating start-stop. Specifically, when the instantaneous flow rate of each waste heat source input loop is lower than the preset effective flow rate threshold, and the temperature of the high-temperature buffer tank 8 is lower than the preset guaranteed temperature, the electric heater in the high-temperature buffer tank 8 can be started to provide auxiliary heating for the liquid in the high-temperature buffer tank 8; when the temperature of the high-temperature buffer tank 8 rises to the preset stop temperature, the electric heater is stopped; when the liquid level of the high-temperature buffer tank 8 is lower than the minimum protection liquid level, the electric heater is cut off or its start is prohibited to prevent the electric heater from dry burning. Furthermore, the low-limit temperature maintenance and differential start-stop method, the low liquid level interlock cut-off method, and the control method of the electronic boiler temperature controller can all be implemented using existing conventional control units.

[0060] It should be understood that the terms "system," "device," "unit," and / or "module" as used in this specification are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0061] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0062] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

[0063] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

Claims

1. A multi-heat-source staged buffer heating device for a water source heat pump, characterized in that, include: At least two parallel waste heat source input circuits are provided. The waste heat source input circuits are equipped with a temperature sensor (1), a flow meter (2), an inlet check valve (3), and a one-in-three-outlet distribution mechanism (4) in sequence. The three outlets of the one-in-three-outlet distribution mechanism (4) are respectively connected to the high-temperature main pipe (5), the medium-temperature main pipe (6), and the low-temperature main pipe (7). The high-temperature main pipe (5) is connected to the high-temperature buffer tank (8), the medium-temperature main pipe (6) is connected to the medium-temperature buffer tank (9), and the low-temperature main pipe (7) is connected to the low-temperature buffer tank (10). The installation elevations of the high-temperature buffer tank (8), the medium-temperature buffer tank (9), and the low-temperature buffer tank (10) decrease in sequence. A first overflow channel (11) is provided between the high-temperature buffer tank (8) and the medium-temperature buffer tank (9), and a second overflow channel is provided between the medium-temperature buffer tank (9) and the low-temperature buffer tank (10). The medium-temperature buffer tank (9) is equipped with a homogenization loop consisting of a water inlet pipe (13), a variable frequency circulating water pump (14), and a return water pipe (15). The high-temperature buffer tank (8), the medium-temperature buffer tank (9), and the low-temperature buffer tank (10) are all equipped with tank temperature sensors (16), and the medium-temperature buffer tank (9) is also equipped with a liquid level sensor. The high-temperature buffer tank (8) is connected to the high-temperature output branch, the medium-temperature buffer tank (9) is connected to the medium-temperature output branch, and the low-temperature buffer tank (10) is connected to the low-temperature output branch. The high-temperature output branch, the medium-temperature output branch, and the low-temperature output branch are all equipped with electric regulating valves (17) and outlet check valves (18). The high-temperature output branch, the medium-temperature output branch, and the low-temperature output branch all converge into a mixed output main pipe equipped with a main water supply pump (19) and an end temperature sensor (20). It also includes a PLC control cabinet (21) connected to a temperature sensor (1), a flow meter (2), a one-in-three-out distribution mechanism (4), a tank temperature sensor (16), a liquid level sensor, a variable frequency circulating water pump (14), an electric regulating valve (17), a main water supply pump (19), and an end temperature sensor (20). The PLC control cabinet (21) is used to control the corresponding one-in-three-out distribution mechanism (4) to introduce the waste heat source into the corresponding main pipe according to the inlet temperature and instantaneous flow of each waste heat source input circuit, and to adjust the opening of the electric regulating valve (17) on each output branch according to the detection value of the end temperature sensor (20) and each tank temperature sensor (16) to output the mixed water.

2. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The inlet of the high temperature buffer tank (8) is located at the top or upper end of the tank body, and the outlet of the high temperature buffer tank (8) is located on the upper side wall of the tank body at a position corresponding to 80% to 90% of the effective height of the tank body.

3. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1 or 2, characterized in that, The high-temperature buffer tank (8) is equipped with an electric heater; the electric heater is an immersion electric heating tube; the electric heater is installed at the bottom of the high-temperature buffer tank (8); the PLC control cabinet (21) is connected to the electric heater.

4. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The first overflow channel (11) is provided with a first one-way check valve that allows liquid to flow from the high temperature buffer tank (8) to the medium temperature buffer tank (9); the second overflow channel (12) is provided with a second one-way check valve that allows liquid to flow from the medium temperature buffer tank (9) to the low temperature buffer tank (10).

5. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The inlet of the return water pipe (15) is tangentially arranged relative to the inner wall of the medium temperature buffer tank (9), and the axis of the return water pipe (15) is inclined downward at 15° to 30°. The inlet position of the return water pipe (15) corresponds to 30% to 40% of the effective height of the medium temperature buffer tank (9). The tank temperature sensor (16) on the medium-temperature buffer tank (9) is a multi-point temperature measurement component, which includes multiple temperature measurement points respectively set in the upper, middle and lower parts of the medium-temperature buffer tank (9).

6. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The inlet of the low-temperature buffer tank (10) is located at the bottom of the tank body, and the outlet of the low-temperature buffer tank (10) is located at the lower part of the side wall of the tank body, corresponding to 20% to 30% of the effective height of the tank body.

7. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The effective volume of the low-temperature buffer tank (10) is greater than that of the medium-temperature buffer tank (9), the effective volume of the medium-temperature buffer tank (9) is not less than that of the high-temperature buffer tank (8), and the effective volume of the low-temperature buffer tank (10) is not less than the sum of the effective volumes of the high-temperature buffer tank (8) and the medium-temperature buffer tank (9).

8. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The high-temperature buffer tank (8) and the low-temperature buffer tank (10) are respectively equipped with liquid level detection elements, which are connected to the PLC control cabinet (21).

9. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The top of the high-temperature buffer tank (8), the medium-temperature buffer tank (9) and the low-temperature buffer tank (10) are all equipped with a breather valve.

10. A multi-heat-source staged buffer heating device for a water source heat pump according to claim 1, characterized in that, The one-in-three-out distribution mechanism (4) is a three-position four-way electric distribution valve or an equivalent one-in-three-out distribution valve group formed by multiple electric valves through interlock control. All three main pipes are made of seamless steel pipes, and the outer walls of all three main pipes are covered with polyurethane insulation layer. The three main pipes are laid in the same direction. The electric regulating valve (17) on each output branch is an electric proportional regulating valve with equal percentage flow characteristics. The main water supply pump (19) is a variable frequency centrifugal water pump.

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