Dual-energy coupling cross-regional collaborative cooling and heating system and flexible control method

Abstract

The invention relates to the technical field of heating, ventilation and air conditioning and regional energy systems, in particular to a dual-energy coupled cross-regional collaborative cooling and heating system and a flexible control method. The system is composed of heat pump unit units serving two independent areas, an electrode boiler auxiliary heat source unit, a frequency conversion circulating water system, a valve system and a flexible control system, part of heat pump units are designed to be capable of being switched across the areas, and energy supply complementation between the two areas is achieved; the flexible control method comprises five levels: self-adaptive frequency conversion adjustment of a single heat pump based on load and temperature deviation, time sequence cooperative operation of a plurality of heat pumps and a circulating pump in an area, and heat pump and electrode boiler dual-energy coupling and intelligent switching based on environment temperature and heat pump energy efficiency. Cross-region collaborative energy supply scheduling follows a local region priority and cross-region supplement principle and a safe redundancy and fault rapid switching mechanism under abnormal conditions. According to the invention, through intelligent prediction, dynamic matching and multi-energy cooperation, energy efficiency optimization and load balancing of the energy supply system are realized.

Description

Technical Field

[0001] This invention relates to the field of heating, ventilation, air conditioning and regional energy system technology, specifically to a dual-energy coupled cross-regional coordinated cooling and heating system and a flexible control method. Background Technology

[0002] Building operation energy consumption accounts for 21.7% of the total social energy consumption in China, of which HVAC systems account for more than 60% (data from the Ministry of Housing and Urban-Rural Development in 2024). Air source heat pumps can provide heating in winter and cooling in summer, and have a high coefficient of performance (COP), making them a key clean energy technology promoted by the national "dual carbon" strategy. However, due to the problem of low-temperature performance degradation, the energy supply capacity and efficiency decrease in extreme low-temperature weather. Conventional air source heat pump equipment is difficult to use in occasions with high energy supply safety requirements (such as hospitals). Increasing the energy supply power or using low-temperature air source heat pumps will increase investment and limit their application.

[0003] When an energy station supplies energy to multiple regions simultaneously, and the energy supply load curves of different regions are different, a cross-regional collaborative approach can be considered. Cross-regional collaboration has advantages such as load balancing and maximizing equipment resource utilization. It breaks down spatial barriers, upgrades from "passive response" to "active adaptation," and ultimately achieves reliable energy supply and optimal energy efficiency at all times. The energy supply plan can be optimized through cross-regional collaboration to reduce initial investment costs.

[0004] Hospitals, commercial complexes, and other public buildings experience large load fluctuations. Cross-zone collaboration can smooth out peak loads (e.g., calling on units in another zone when the load in one zone suddenly increases), avoiding the waste of equipment that is "overpowered." Dual-energy coupling (heat pump + boiler) under extreme weather conditions solves the problem of "low-temperature energy efficiency degradation" in traditional heat pump systems. The "dual-energy coupling, cross-zone collaboration" HVAC system of this invention features maximized equipment utilization (reducing construction investment costs), optimized operating costs, improved system stability and flexibility, and high flexibility in system upgrades. It can meet the heating and cooling needs of various zones in a large building complex while achieving a "double reduction" in costs (construction and operation) and carbon emissions. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the background technology by proposing a dual-energy coupled cross-regional coordinated cooling and heating system and a flexible control method.

[0006] The technical solution of this invention: a flexible control method for cross-regional coordinated cooling and heating with dual-energy coupling, the specific implementation steps of which include: S1. Based on the instantaneous power of each heat pump unit and the deviation between the indoor temperature of the service area and the set value, the compressor speed of each heat pump is adjusted in stages. When the load increases, high frequency operation is adopted; when the load is stable, medium and low frequency operation is adopted; and when the load is stable, deep energy-saving mode can be entered. When the load decreases, the frequency is gradually reduced to shutdown, and speed compensation is performed according to the extreme ambient temperature in winter and summer. S2. The total load rate of the area changes beyond a set range as a trigger signal, and the start-up and shutdown of multiple heat pumps and the speed adjustment of the circulation pump in the area are coordinated. The circulation pump is adjusted in a closed loop based on the pressure difference between the supply and return water and the flow rate, and is coordinated with the adjustment of the heat pump in a timely manner, including increasing the circulation pump speed in advance before the heat pump compressor speeds up, delaying the reduction of the circulation pump speed after the heat pump compressor speeds down, and keeping the circulation pump speed stable during the addition and removal of the heat pump. S3, under heating mode, the system operates in segments according to the outdoor ambient temperature. In the mild low temperature segment, the heat pump is the main heat source and the boiler is used for peak regulation. In the deep low temperature segment, the boiler is the main heat source and the heat pump operates at a low load to ensure basic operation. The boiler's start-up, shutdown and output power are dynamically controlled based on the ambient temperature and the heat pump's energy efficiency ratio. A tiered heating method of heat pump preheating and boiler secondary heating is adopted. S4. Following the principle of prioritizing this area and supplementing across areas, cross-area support is only triggered after all available heat pumps in this area are fully loaded. The switchable heat pumps in the other area are connected to the demand area's pipeline network through the valve switching of the circulation system, and are uniformly dispatched by the demand area. If there is still a load gap after all heat pumps in both areas are fully loaded, the electrode boiler is activated and heat is distributed to both areas as needed. S5. In cooling mode, when a single heat pump fails, the compressor speed of other units in the same area is increased first. If the power is still insufficient, cross-regional coordination is triggered. In heating mode, when a single heat pump fails, the power of other units in the same area is increased first. If the power is still insufficient, cross-regional coordination is triggered or the boiler is started. When cross-regional coordination fails, the compressor speed of the local unit is increased and a boiler is prepared to supplement the power. When a single boiler fails, another boiler is started and runs at full load, and the heating intensity in non-core areas is adjusted.

[0007] Preferably, in step S1, the phased adjustment specifically includes: When the instantaneous load rate exceeds 60% or the difference between the indoor temperature and the set value is ≥2℃, the compressor is controlled to start at 80% to 100% of the rated speed. When the instantaneous load rate is stable in the range of 30% to 50%, the compressor is controlled to run at 30% to 50% of the rated speed. After the set time is maintained in this state, it can enter the deep energy-saving mode and further reduce the speed to 25% to 35% of the rated speed. In cooling mode, when the instantaneous load rate is below 20% or the indoor temperature is 1°C below the set value, the compressor speed is gradually reduced to 20% to 30% of the rated speed, and cooling is suspended after the low load condition is maintained for a set time. In heating mode, when the instantaneous load rate is below 20% or the indoor temperature is 1°C above the set value, the compressor speed is gradually reduced to 20% to 30% of the rated speed, and heating is suspended after the low load condition is maintained for a set time.

[0008] Preferably, in step S2, the timing coordination specifically includes: When the control system commands a heat pump to increase the compressor speed, it sends a speed-up command to the circulating pump that is in operation in that area 10 seconds in advance. When the control system instructs a heat pump to reduce the compressor speed, it delays for ten seconds before sending a speed reduction command to the circulating pumps that are in operation in that area. During the critical transition period of starting or stopping the heat pump unit, the current speed of the circulating pump in operation should be kept unchanged, and the pump speed should be readjusted after the heat pump operation is stable.

[0009] Preferably, in step S3, the segmented operation is as follows: When the ambient temperature is between -5℃ and 5℃ and the average energy efficiency ratio of the heat pump is ≥2.0, the heat pump is controlled to bear 80% to 90% of the design heat load, and the boiler bears the peak load. When the ambient temperature is ≤-20℃, the heat pump is controlled to operate at 10% to 20% of its rated output, and the boiler undertakes 80% to 90% of the main heating load.

[0010] Preferably, in step S4, triggering cross-region support also requires the following conditions to be met simultaneously: There is a persistent load gap in the demand area; The switchable heat pumps in the support area still have available capacity after meeting the load demand of their own area; The above conditions must be met continuously for more than five minutes.

[0011] Preferably, in step S5, the handling of a single heat pump failure also includes: Immediately close the inlet and outlet valves of the faulty unit to isolate it from the circulating water system.

[0012] Preferably, step S3 further includes an antifreeze protection strategy: When the ambient temperature is ≤-20℃, at least one electrode boiler is forced to maintain a minimum output of 15% to 20% to ensure that hot water continues to circulate in the pipe network.

[0013] Preferably, step S2 further includes a system energy-saving optimization strategy: During preset low-load periods, the target differential pressure setting of the circulation system is automatically reduced and the minimum speed limit of the circulation pump is relaxed. When the total load factor of the region remains below the set threshold and no upward trend is predicted, the control system enters a sleep mode, the circulating pump maintains the minimum circulation flow at an extremely low speed, and all heat pump units are shut down or put on standby.

[0014] The technical solution of this invention: A dual-energy coupled cross-regional coordinated cooling and heating system, used to execute the above-mentioned dual-energy coupled cross-regional coordinated cooling and heating flexible control method, comprising: The heat pump unit includes at least two local heat pump units and one switchable heat pump unit located in the first zone, and at least two local heat pump units and one switchable heat pump unit located in the second zone. The switchable heat pump unit can be switched to the pipe network of another zone via a valve. The electrode boiler auxiliary heat source unit includes at least two electrode boilers, which are connected to the main supply and return water pipes of the first and second zones through a network of multiple electrically operated switching valves. The variable frequency circulating water system includes multiple variable frequency circulating pumps respectively installed in the first and second zones, as well as a variable frequency hot water circulating pump independently configured for the electrode boiler unit. The valve system includes electrically operated on / off valves installed at the inlet and outlet of each heat pump unit, a main valve installed on the main supply and return water pipes of each area, a coordinated switching valve for switching the pipelines of switchable heat pump units, and a boiler switching valve for guiding the flow of boiler hot water. The flexible control system is configured to execute control methods, including a data acquisition and monitoring module for data acquisition and monitoring, a load forecasting module for load prediction, an equipment capacity calculation and matching module for equipment capacity calculation and matching, a collaborative control algorithm module for executing collaborative control algorithms, and a safety protection and fault handling module for safety protection and fault handling.

[0015] Compared with the prior art, the above-mentioned technical solution of the present invention has the following beneficial technical effects: This invention designs a dual-energy coupled cross-regional coordinated cooling and heating system and a flexible control method. Through dual-energy coupling and cross-regional coordinated flexible control strategies, it achieves significant improvements in energy efficiency, reliability, and adaptability of the cooling and heating system. The system can intelligently schedule the coordinated operation of heat pump units and electrode boilers based on real-time load and environmental conditions. Under normal conditions, it prioritizes the use of high-efficiency heat pumps to meet the base load, and automatically switches to boilers for supplementation during extreme low temperatures or load peaks, thereby ensuring optimal energy utilization efficiency under all operating conditions. The cross-regional coordinated mechanism breaks down energy barriers between regions through switchable units and... Intelligent valves enable dynamic adjustment of load surplus and shortage, improving overall equipment utilization and system energy balance. Multi-level control methods achieve refined management from single-unit frequency conversion regulation to system-wide coordinated operation, effectively avoiding frequent equipment start-ups and shutdowns and hydraulic imbalances, enhancing system stability and response speed. Furthermore, embedded fault diagnosis and redundancy strategies can quickly switch energy sources or call upon backup resources when critical equipment malfunctions, significantly improving system resilience and continuous energy supply capability. This invention's entire solution balances the priority use of clean energy with a safe backup energy supply, possessing broad engineering applicability and scalability. Attached Figure Description

[0016] Figure 1 This is a framework diagram of a dual-energy coupled cross-regional coordinated cooling and heating system proposed in this invention; Figure 2 This is a flowchart of a dual-energy coupled cross-regional coordinated cooling and heating flexible control method proposed in this invention. Detailed Implementation

[0017] Example 1: The present invention proposes a dual-energy coupled cross-regional coordinated cooling and heating system, such as... Figure 1 As shown, it primarily serves two independent energy supply areas (Zone 1 and Zone 2), achieving energy coupling and synergy through physical pipelines and intelligent control, including: Heat pump unit: Zone 1 heat pump units: equipped with three evaporator-condenser heat pump coupled units, numbered A1-1, A1-2, and A1-3; each unit is an inverter model, and its cooling / heating power can be continuously adjusted within the range of 10% to 100% of the rated power; Zone 2 heat pump units: equipped with three evaporator-condenser coupled with heat pump units, numbered A2-1, A2-2, and A2-3; performance parameters are the same as those of the units in Zone 1. Cross-regional coupling design: Unit A1-1 in Zone 1 and Unit A2-1 in Zone 2 are specially designed as "switchable units"; through specific valve switching operations, Unit A1-1 can disconnect from the Zone 1 pipeline network and connect to the Zone 2 pipeline network for power supply; similarly, Unit A2-1 can also switch to the Zone 1 pipeline network for power supply; the remaining units (A1-2, A1-3, A2-2, A2-3) are "local units" that are fixed to serve this region; Auxiliary heat source unit for electrode boiler: The system is equipped with two electrode hot water boilers, numbered C1 and C2, as auxiliary and backup heat sources; the heating power of each boiler can be adjusted within the range of 5% to 100% of the rated power. This unit is connected to the main heating return and supply water pipes of Zone 1 and Zone 2 through a network of eight electrically operated switching valves (SV1 to SV8). By controlling the opening and closing combinations of these valves, various flexible operating conditions can be achieved, such as C1 or C2 supplying heat to Zone 1 alone, supplying heat to Zone 2 alone, distributing heat to both zones on demand at the same time, or taking over the full load of one boiler when one boiler fails. Variable frequency circulating water system: The main circulation system of the area is as follows: three variable frequency hot and cold water circulation pumps P1-1, P1-2, and P1-3 are configured in the first area and installed in parallel on the main water supply / return pipe of the first area; three variable frequency circulation pumps P2-1, P2-2, and P2-3 are symmetrically configured in the second area. Boiler circulation system: The electrode boiler unit is independently equipped with two variable frequency hot water circulation pumps CP1 (corresponding to C1) and CP2 (corresponding to C2). Valve system: Unit valves: Each heat pump unit (A1-1 to A2-3) is equipped with an electric on / off valve (such as V-A1-1-IN, V-A1-1-OUT) at both the inlet and outlet. Main valves for zones: Main valves V-A1-OUT, V-A1-IN and V-A2-OUT, V-A2-IN are respectively installed on the main water supply pipes and main water return pipes of zones one and two; Cross-zone coordination valves: key valves used to realize pipeline switching of switchable units (A1-1, A2-1), including the first zone coordination valves V-A1-S-IN and V-A1-S-OUT, and the second zone coordination valves V-A2-S-IN and V-A2-S-OUT; Boiler switching valves: as mentioned above, SV1 to SV8, are used to guide the flow of hot water in the boiler; Flexible control system: Its hardware includes an industrial controller, data acquisition modules (I / O modules), and a human-machine interface (HMI); the software integrates the following key functional modules: Data acquisition and monitoring module: Real-time acquisition of signals from all temperature, pressure, and flow sensors, as well as the operating status and fault signals of all water pumps, units, boilers, and valves; Load forecasting module: Built-in load forecasting model based on machine learning algorithm; the input of this model includes: historical load data for the same period, weather forecast for the next 24 hours (especially temperature), building schedule (such as outpatient hours, operating room opening schedule, etc.); the model can predict the cold / heat load change trend of Zone 1 and Zone 2 relatively accurately 15-30 minutes in advance; Equipment capacity calculation and matching module: calculates the real-time output and remaining available capacity of each operating heat pump unit in the system, as well as the current output and standby capacity of the electrode boiler. Collaborative control algorithm module: This is where the core control logic is located. Based on load forecast results, real-time monitoring data, and equipment capacity calculation results, it executes all control strategies and generates precise control commands for compressor frequency, water pump speed, valve opening and closing, and boiler power. Safety protection and fault handling module: Monitors key system parameters and executes preset safety interlocks and fault switching logic when abnormalities occur (such as over-temperature, over-pressure, or equipment failure).

[0018] Example 2: The present invention proposes a dual-energy coupled cross-regional coordinated cooling and heating flexible control method, which is applied to a dual-energy coupled cross-regional coordinated cooling and heating system proposed in Example 1, such as... Figure 2 As shown, it includes: S1. Set an adaptive frequency converter control program for a single heat pump unit. Based on the deviation between the instantaneous load rate of the area and the indoor temperature and the set value, adjust the compressor speed in stages: high-frequency start when the load increases (e.g., 80%-100%), medium-low frequency operation when stable (e.g., 30%-50%), and can enter a deep energy-saving mode when the load remains stable. When the load decreases, gradually reduce the frequency until shutdown, and automatically compensate for the speed according to extreme winter and summer temperatures to achieve precise energy supply and efficiency optimization. Specifically: Adjustment basis: The "instantaneous load rate" (the percentage of the current actual load to the total design load of the area) and the "deviation of the indoor average temperature from the set value" of the area served by the unit are used as the main input parameters; Load ramp-up control: When the indoor temperature deviates from the set value by ≥2℃ or the instantaneous load rate exceeds 60%, it is determined to be a period of rapid demand increase. The system instructs the compressor of the heat pump to start directly at a high frequency of 80%-100% of the rated speed, so that it can quickly reach a high heat exchange capacity state within 1-2 minutes and quickly close the gap between the room temperature and the set value. When the load rate drops to the range of 50%-70%, the control system switches the compressor speed to the medium frequency range (e.g., 50%-70% of the rated speed). During this stage, the system reads the data of the high-precision indoor temperature sensor every 30 seconds and makes a fine adjustment to the speed of the heat pump compressor. The adjustment range is controlled between ±5% and ±10% of the current speed, which aims to smooth the transition and avoid indoor temperature fluctuations and equipment wear caused by frequent and large speed adjustments. Load stabilization phase control: When the system determines that the load rate has stabilized in the 30%-50% range, it indicates that demand has entered a stable period. At this time, the control system instructs the heat pump compressor to operate at a low frequency of 30%-50% of its rated speed. Through the closed-loop PID control of the inverter, the indoor temperature fluctuations in the served area can be strictly controlled within a comfortable range of ±0.5℃. If the load rate (especially around 40%) is detected to be stable for more than 10 minutes, the control system automatically activates the "deep energy-saving mode". In this mode, the compressor speed will be further reduced to 25%-35% of the rated speed. This strategy will slightly sacrifice the response speed of temperature regulation (for example, the time from changing the set value to reaching a new steady state will be extended by 1-2 minutes), but it can be exchanged for a significant energy-saving effect of reducing the unit's energy consumption by 15%-20%. Load reduction phase control: When the load rate drops below 20%, or when the average indoor temperature is detected to be 1°C lower than the set value, the system begins to enter the load reduction program; the compressor speed is gradually and smoothly reduced to a low operating level of 20%-30% of the rated speed; if this low load state (load rate <15%) lasts for more than 10 minutes, the control system will issue a "pause cooling / heating" command: the compressor and condenser fan stop running, and only the indoor fan is kept running at the lowest speed to maintain air circulation to prevent zonal temperature stratification; once the load rate sensor detects that the demand has rebounded to above 25%, the compressor is immediately restarted, and the speed is gradually increased from the medium frequency to match the new load demand; Special environmental conditions compensation control: Winter low temperature operation: When the outdoor ambient temperature sensor reading is ≤-5℃, the control system automatically increases the "basic operating speed" of all operating heat pump units to no less than 50% of the rated speed; at the same time, it judges the defrosting demand based on the evaporator fin temperature and pressure difference, and only starts the defrosting program when the heating capacity is obviously insufficient, so as to avoid unnecessary heat loss. High-temperature operation in summer: When the outdoor ambient temperature is ≥35℃, in order to prevent the compressor exhaust temperature from being too high and triggering protective shutdown, the control system will limit its maximum operating speed to no more than 80% of the rated speed. Under this restriction, if the cooling load demand is still large, the system will meet the total cooling demand by extending the continuous operation time of a single unit, rather than blindly increasing the speed.

[0019] S2. Set a collaborative control program for multiple heat pumps and circulating pumps within a region. A change in the region's total load rate exceeding ±10% serves as a trigger signal, triggering collaborative control of heat pump start-up and shutdown and circulating pump speed adjustment. The circulating pump performs closed-loop regulation based on the supply and return water pressure difference and flow rate, maintaining timing coordination with the heat pump regulation: the heat pump speed is increased 10 seconds before acceleration and decreased 10 seconds after deceleration, maintaining a stable pump speed during acceleration / deceleration. At night or under low load, it automatically reduces pressure difference, speed, or even enters sleep mode. That is, within a single region (zone 1 or zone 2), multiple heat pump units and circulating water pumps are treated as a whole and coordinated by the control system, based on the principles of "load linkage, energy efficiency priority, and hydraulic balance," specifically: Coordination trigger signal: The "total instantaneous load rate" of the region is used as the core coordination signal; when the change in the total load rate exceeds ±10%, the cluster adjustment procedure is triggered. Equipment start-up and shutdown (addition / reduction) coordination: Based on the total load factor, decide whether to start or stop one heat pump unit; For example, when the total load rate of Zone 1 continues to rise from 65% to 80%, the system may determine that it is necessary to start up Unit A1-2; the issuance of the add / remove unit command will simultaneously trigger the adjustment preparation of the circulating pump. Fine-tuning of the circulating pump: The speed regulation of the circulating pump follows the following sub-strategies, and is strictly coordinated with the heat pump regulation in terms of timing: Strategy 1: Adjustment based on supply and return water pressure difference (main strategy): Install a pressure difference sensor between the regional supply and return water mains; set a target pressure difference range for the control system (e.g., 0.15-0.2 MPa); when the measured pressure difference is 10% higher than the upper limit of the target value, gradually reduce the circulation flow rate by decreasing the total speed of the circulation pump by 5% every 30 seconds; conversely, when the measured pressure difference is 10% lower than the lower limit of the target value, gradually increase the speed; this strategy can automatically adapt to changes in the opening of the terminal valves and maintain the hydraulic balance of the system. Strategy 2: Verification and adjustment based on design flow rate (auxiliary strategy): The total circulation flow rate is monitored in real time by an electromagnetic flow meter on the main pipe; if the flow rate is consistently lower than 80% of the design flow rate, the system will exceed the differential pressure signal and forcibly increase the speed of the circulation pump to ensure sufficient water circulation; at the same time, the system monitors the opening of the electric valves of important branch lines at the end. If it is found that the opening of most valves is consistently lower than 50%, it is determined that the overall flow rate of the system is too high, and the speed of the circulation pump will be gradually reduced until the average valve opening returns to the efficient adjustment range of 60%-80%; Timing coordination with heat pump output: Adjustment 1: Anticipatory Adjustment: When the control system instructs a heat pump to increase the compressor speed to increase output, it will send an acceleration command to the circulation pump in that area 10 seconds in advance; this ensures that when the heat exchange capacity of the heat pump is enhanced, the water flow through its condenser / evaporator has increased synchronously, avoiding the problem of reduced heat exchanger efficiency due to "small flow rate and large temperature difference"; Adjustment 2: Lag adjustment: When the heat pump reduces its speed, the corresponding circulation pump's speed reduction command will be executed 10 seconds later; this ensures that during the transition period of the heat pump's output reduction, there is still enough flow to remove the remaining heat, preventing abnormal rise or fall of the working fluid temperature in the heat exchanger. Stability priority during heat pump unit startup and shutdown: During the critical 2-3 minute transition period when the heat pump unit starts or stops, the control system will "freeze" the speed adjustment of the circulating pump and maintain the current speed unchanged; after the heat pump unit's operating status stabilizes (current and water temperature tend to be stable), the circulating pump speed will be recalculated and adjusted according to the new total system load; this effectively avoids hydraulic shock and pressure fluctuations caused by sudden changes in flow rate. System-wide energy-saving optimization strategy: Mode 1: Night and Low Load Mode: During the preset low load period (e.g., from 22:00 to 6:00 the next day), the control system automatically lowers the target differential pressure setting to 0.1-0.15MPa, and at the same time relaxes the minimum speed limit of the circulating pump from the usual 30% to 20% of the rated speed, further reducing the energy consumption of the water pump. Mode 2: System hibernation mode: When the total load rate of the area is below 20% for 30 consecutive minutes and is not expected to rise in the short term, the system enters "hibernation mode". In this mode, the circulating pump operates at a very low speed of 15% of the rated speed, maintaining only the minimum circulation flow required to prevent pipe freezing or gas accumulation. All heat pump units are in a stopped or standby state.

[0020] S3. A dual-energy coupling and intelligent switching program for the heat pump and electrode boiler is set, operating in segments according to ambient temperature: -5℃ to 5℃, the heat pump is the main power source (handling 80%-90% of the load), with the boiler handling peak loads; ≤-20℃, the boiler is the main power source (80%-90%), with the heat pump operating at low load (10%-20%). The boiler is dynamically started and stopped based on ambient temperature and the heat pump COP value, using a tiered approach of heat pump preheating + boiler secondary heating. It also features low-temperature antifreeze and rapid fault switching functions. This strategy is specifically designed for winter heating conditions, solving the problem of low-temperature performance degradation in air-source heat pumps, prioritizing cleanliness while ensuring safety. Specifically: Load and energy efficiency segmented coordination mechanism: (1) Mild low temperature range (ambient temperature -5℃~5℃): Air source heat pump is the absolute dominant heat source; when the average operating energy efficiency ratio (COP) of the heat pump unit is ≥2.0, the control system schedules the heat pump to undertake 80%-90% of the design heat load in this area; the electrode boiler is in hot standby state and is only started when the instantaneous load has an abnormal peak that exceeds the current total output capacity of the heat pump, undertaking 10%-20% of the peak load, and then shutting down; (2) Deep low temperature section (ambient temperature ≤ -20℃): The efficiency of the heat pump drops significantly in this section (COP may be ≤ 1.2); the control system switches to the joint operation mode of "heat pump backup + boiler main force"; the heat pump units that are still running are instructed to maintain a low load of 10%-20% of the rated output, in order to keep the heat pump system running and prevent freezing and other problems; at the same time, the electrode boiler is started as the main heat source, undertaking 80%-90% of the main heating load; this avoids the heat pump from operating at high energy consumption under extremely low energy efficiency, and also utilizes its ability to preheat return water; Dynamic switching control logic: Condition 1: Boiler start-up trigger condition: The control system continuously monitors two key parameters - outdoor ambient temperature and the average COP of the heat pump during operation; when the ambient temperature is ≤ -3℃ and the average COP of the heat pump is below 1.6 for 10 minutes, it is determined that the heat pump system has entered the inefficient range; the control system immediately starts the electrode boiler and instructs it to increase its output to more than 50% within 3 minutes to share the load with the heat pump; Condition 2: Boiler shutdown conditions: When the ambient temperature rises above 0℃ and the average COP value of the operating heat pump recovers to above 2.2 and remains stable, the control system begins to gradually reduce the load of the electrode boiler; first, its output is slowly reduced to within 10% of the "hot standby" state, and after maintaining this state for a period of time to confirm that the heat pump can independently meet the demand, the boiler is completely shut down. Cascade heating energy efficiency optimization: To fully utilize the relative energy efficiency advantage of heat pumps at low temperatures, the system adopts a cascade heating process. The heat pump unit first heats the system's return water temperature from a lower value (e.g., 35℃) to an intermediate temperature (45℃-55℃). Then, this preheated water flows through the electrode boiler, where it undergoes secondary heating to reach the final required supply water temperature (55℃-60℃). Compared to heating entirely from low temperatures by the boiler, this method reduces the boiler's total power consumption. Safety and fault response strategies: (1) Freeze protection: When the ambient temperature is ≤-20℃, regardless of the load demand, the control system will force at least one electrode boiler to maintain 15%-20% of the minimum output, so that the hot water it produces will continue to circulate in the pipe network, providing basic freeze protection for the entire system; (2) Seamless switching of heat pump failure: If a heat pump or a group of heat pumps stops due to an alarm caused by a compressor failure, the control system can detect it within 3 seconds; it will quickly increase the output of the electrode boiler to the required level within 3 minutes, or start the standby heat pump unit to ensure that the heating load is not interrupted and the fluctuation of the system water supply temperature is controlled within the allowable range.

[0021] S4. Set up a cross-regional collaborative energy supply dispatching procedure, following the principle of "priority to this region, supplementation to other regions." Cross-regional support will only be triggered after all heat pumps in this region are at full load, with a 5-minute delay to prevent accidental activation. Connect the standby heat pump from another region to the demand region's pipeline network via a valve switching mechanism, allowing for unified dispatch. If there is still a load shortfall of more than 5% even when both heat pumps in both regions are at full load, the electrode boiler will be activated proportionally to supplement the load. The boiler can flexibly distribute heat to both regions, specifically as follows: The control system always follows the principle of "local priority, cross-regional supplementation"; that is, it prioritizes the use of all heat pump resources in the local area (including local units and switchable units in the local area) to meet the local load; only after all available heat pumps in the local area have reached full load output (100%), if there is still a load gap, will it request support from another area. Detailed process for example, "Load shortage in Zone 1, requesting support from Zone 2": (1) Resource allocation sequence in this area: When the load in the first area increases, the control system starts up in sequence: Step 1: Prioritize starting and adjusting the frequency converters of local units A1-2 and A1-3 to match the load; Step 2: If A1-2 and A1-3 both reach 100% output but are still insufficient, start the switchable unit A1-1 in this area and connect it to the first area's pipeline network to supply energy to this area (at this time, A1-1 is not used as an inter-area backup). (2) Cross-regional coordination trigger judgment: When all three units A1-1, A1-2 and A1-3 are running at full load, the control system calculates the load gap of the first zone in real time; at the same time, it continuously monitors the operating status of the heat pump system in the second zone; triggering cross-regional coordination requires two conditions to be met at the same time: ① There is a continuous load gap in the first zone; ② The switchable unit A2-1 in the second zone still has remaining available capacity after prioritizing the load demand of the second zone itself; (3) Anti-malfunction delay: In order to prevent frequent cross-regional switching due to short-term (such as a few minutes) load fluctuations, the system is set with a 5-minute judgment delay; that is, the above triggering conditions must be met continuously for more than 5 minutes before the control system will officially issue a cross-regional coordination command. (4) Implement cross-regional collaboration: Valve switching: The flexible control system automatically executes the valve operation sequence: First, it closes the original inlet and outlet valves (V-A2-1-IN and V-A2-1-OUT) of Unit A2-1 in Zone 2, disconnecting it from the local pipeline network of Zone 2; then, it opens the Zone 2 coordination valves (V-A2-S-IN and V-A2-S-OUT), connecting the pipeline of A2-1 to the dedicated inter-zone pipeline; at the same time, it ensures that the corresponding coordination valves (V-A1-S-IN and V-A1-S-OUT) in Zone 1 are in the open state; Transfer of control: Logically, the control of unit A2-1 is transferred from "local unit in zone 2" to "supplementary unit in zone 1"; its operating frequency is no longer determined by the load in zone 2, but is uniformly scheduled by the total load control algorithm of zone 1, and it operates in coordination with A1-1, A1-2 and A1-3. Hydraulic system adjustments: The circulation pumps in Zone 1 (P1-1~P1-3) will have their speeds readjusted based on the new total load (including the addition of A2-1); the circulation pumps in Zone 2 (P2-1~P2-3) will have their speeds readjusted based on the local load after the output of A2-1 has been reduced. Ultimate supplement after both zones are fully loaded: Electrode boiler commissioning: When all heat pump units in Zone 1 and Zone 2 (including units currently providing cross-zone support) have reached 100% full-load operation, but the total heating / cooling capacity of the system is still more than 5% lower than the total demand, the system is determined to enter an "extreme load state". At this time, the flexible control system will activate the final energy supplementation plan - put the electrode boiler into operation. Power distribution: The control system distributes output commands to the two electrode boilers (C1, C2) according to the real-time total load deficit ratio; for example, if the total deficit is 30% of the design load, C1 and C2 may each be instructed to bear 15% of the load; the distribution algorithm can take into account the boiler's operating time balance. Cross-zone heating distribution: Hot water produced by the boiler can be flexibly distributed through switching valves (SV1-SV8); for example, if the gap in the first zone is much larger than that in the second zone, valves can be set to make the boiler hot water mainly flow to the first zone, and only a small amount flow to the second zone to maintain the base temperature; Exit mechanism: When the total output of the heat pump system recovers its redundancy due to load reduction, the control system prioritizes reducing and stopping the electrode boiler; the boiler shutdown threshold is set at a load gap of less than 2%, with a buffer zone reserved to avoid frequent start-ups and shutdowns at critical points.

[0022] S5. Anomaly handling and safety redundancy control are configured. When a single heat pump fails, other units in the same zone are prioritized for boosting, triggering cross-zone coordination or early boiler startup. If cross-zone coordination fails, the local unit is increased in load and a boiler is prepared for backup. When a single boiler fails, another boiler operates at full load with a moderately relaxed temperature control range in non-core areas to ensure continuous safe system operation. In other words, it incorporates comprehensive fault diagnosis and emergency handling logic to ensure the system maintains core functions even when some equipment fails. Specifically: Single heat pump unit failure: When a heat pump (e.g., A1-2) experiences a fault alarm and shuts down, the control system immediately executes the following: (1) Close the inlet and outlet electric valves of the unit to isolate it from the water system; (2) Prioritize increasing the output of other healthy units (A1-3) in the same area to the maximum limit; (3) If the load increase of the units in the same area is still insufficient to make up for the load gap, the “cross-regional coordination” strategy should be evaluated and implemented immediately, and available resources in another area should be called up (A2-1), or the electrode boiler should be activated in advance as a supplement. Cross-regional coordination pipeline or valve failure: If a cross-regional coordination valve (such as V-A1-S-OUT) is detected to be malfunctioning and unable to open, or if there is a leak in the coordination pipeline, making cross-regional power supply physically impossible: (1) Control system alarm and lock cross-regional collaborative function; (2) In the affected demand areas (such as the first area originally planned to receive assistance), the output limit of its local units may be temporarily relaxed (within the range of equipment safety), and "demand-side response" may be activated in advance, such as slightly adjusting the temperature setpoint of non-critical areas; (3) At the same time, we plan to put the electrode boiler into operation in advance to make up for the energy supply gap caused by the inability to coordinate across regions. Single electrode boiler failure: When one electrode boiler (e.g., C1) fails: (1) The control system immediately closes its inlet and outlet valves to isolate it; (2) Instruct another healthy boiler (C2) to quickly increase its output to its maximum capacity (100%). (3) To avoid overload, the system can simultaneously activate the "load classification management" strategy, for example, temporarily relax the temperature control accuracy requirements for non-core functional areas such as public corridors and halls (allowing them to fluctuate by ±2℃ based on the set value) to ensure stable heating in core areas such as operating rooms and wards.

[0023] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A flexible control method for cross-regional coordinated cooling and heating with dual-energy coupling, characterized in that, Its specific implementation steps include: S1. Based on the instantaneous power of each heat pump unit and the deviation between the indoor temperature of the service area and the set value, the compressor speed of each heat pump unit is adjusted in stages. When the load increases, high frequency operation is adopted; when the load is stable, medium and low frequency operation is adopted; and when the load is stable, deep energy-saving mode can be entered. When the load decreases, the frequency is gradually reduced to shutdown, and speed compensation is performed according to the extreme ambient temperature in winter and summer. S2. The total load change rate of the area exceeds the set range as the trigger signal, and the start-up and shutdown of multiple heat pumps and the speed adjustment of the circulation pump in the area are coordinated. The circulation pump is adjusted in a closed loop based on the supply and return water pressure difference and flow rate, and is coordinated with the heat pump adjustment in a timely manner, including increasing the circulation pump speed in advance before the heat pump compressor speeds up, delaying the reduction of the circulation pump speed after the heat pump compressor speeds down, and keeping the circulation pump speed stable during the heat pump addition and subtraction. S3, under heating mode, the system operates in segments according to the outdoor ambient temperature. In the mild low temperature segment, the heat pump is the main heat source and the boiler is used for peak regulation. In the deep low temperature segment, the boiler is the main heat source and the heat pump operates at a low load to ensure basic operation. The boiler's start-up, shutdown and output power are dynamically controlled based on the ambient temperature and the heat pump's energy efficiency ratio. A tiered heating method of heat pump preheating and boiler secondary heating is adopted. S4. Following the principle of prioritizing this area and supplementing across areas, cross-area support is only triggered after all available heat pumps in this area are fully loaded. The switchable heat pumps in another area are connected to the demand area's pipeline network through the valve switching of the circulation system, and are uniformly dispatched by the demand area. In the heating mode, if there is still a load gap after all heat pumps in both areas are fully loaded, the electrode boiler is activated and heat is distributed to both areas as needed. S5. In cooling mode, when a single heat pump fails, the compressor speed of other units in the same area is increased first. If the power is still insufficient, cross-regional coordination is triggered. In heating mode, when a single heat pump fails, the power of other units in the same area is increased first. If the power is still insufficient, cross-regional coordination is triggered or the boiler is started. When cross-regional coordination fails, the compressor speed of the local unit is increased and a boiler is prepared to supplement the power. When a single boiler fails, another boiler is started and runs at full load, and the heating intensity in non-core areas is adjusted.

2. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 1, characterized in that, In step S1, the phased adjustment specifically includes: When the instantaneous load rate exceeds 60% or the indoor temperature deviation is ≥2℃, the compressor is controlled to start at 80% to 100% of its rated speed. When the instantaneous load rate is stable in the range of 30% to 50%, the compressor is controlled to run at 30% to 50% of the rated speed. After the set time is maintained in this state, it can enter the deep energy-saving mode and further reduce the speed to 25% to 35% of the rated speed. In cooling mode, when the instantaneous load rate is below 20% or the indoor temperature is 1°C below the set value, the compressor speed is gradually reduced to 20% to 30% of the rated speed, and cooling is suspended after the low load condition is maintained for a set time. In heating mode, when the instantaneous load rate is below 20% or the indoor temperature is 1°C above the set value, the compressor speed is gradually reduced to 20% to 30% of the rated speed, and heating is suspended after the low load condition is maintained for a set time.

3. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 2, characterized in that, In step S2, timing coordination specifically involves: When the control system commands a heat pump to increase the compressor speed, it sends a speed-up command to the circulating pump that is in operation in that area 10 seconds in advance. When the control system instructs a heat pump to reduce the compressor speed, it delays for ten seconds before sending a speed reduction command to the circulating pumps that are in operation in that area. During the critical transition period of starting or stopping the heat pump unit, the current speed of the circulating pump in operation should be kept unchanged, and the pump speed should be readjusted after the heat pump operation is stable.

4. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 3, characterized in that, In step S3, the segmented operation is as follows: When the ambient temperature is between -5℃ and 5℃ and the average energy efficiency ratio of the heat pump is greater than or equal to 2.0, the heat pump is controlled to bear 80% to 90% of the design heat load, and the boiler bears the peak load. When the ambient temperature is ≤-20℃, the heat pump is controlled to operate at 10% to 20% of its rated output, and the boiler undertakes 80% to 90% of the main heating load.

5. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 4, characterized in that, In step S4, triggering cross-region support also requires the following conditions to be met simultaneously: There is a persistent load gap in the demand area; The switchable heat pumps in the support area still have available capacity after meeting the load demand of their own area; The above conditions must be met continuously for more than five minutes.

6. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 5, characterized in that, In step S5, the handling of a single heat pump failure also includes: Immediately close the inlet and outlet valves of the faulty unit to isolate it from the circulating water system.

7. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 1, characterized in that, Step S3 also includes antifreeze protection strategies: When the ambient temperature is ≤-20℃, at least one electrode boiler is forced to maintain a minimum output of 15% to 20% to ensure that hot water continues to circulate in the pipe network.

8. The dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to claim 1, characterized in that, Step S2 also includes system energy-saving optimization strategies: During preset low-load periods, the target differential pressure setting of the circulation system is automatically reduced and the minimum speed limit of the circulation pump is relaxed. When the total load factor of the region remains below the set threshold and no upward trend is predicted, the control system enters a sleep mode, the circulating pump maintains the minimum circulation flow at an extremely low speed, and all heat pump units are shut down or put on standby.

9. A dual-energy coupled cross-regional coordinated cooling and heating system, used to execute the dual-energy coupled cross-regional coordinated cooling and heating flexible control method according to any one of claims 1 to 8, characterized in that, include: The heat pump unit includes at least two local heat pump units and one switchable heat pump unit located in the first zone, and at least two local heat pump units and one switchable heat pump unit located in the second zone. The switchable heat pump unit can be switched to the pipe network of another zone via a valve. The electrode boiler auxiliary heat source unit includes at least two electrode boilers, which are connected to the main supply and return water pipes of the first and second zones through a network of multiple electrically operated switching valves. The variable frequency circulating water system includes multiple variable frequency circulating pumps respectively installed in the first and second zones, as well as a variable frequency hot water circulating pump independently configured for the electrode boiler unit. The valve system includes electrically operated on / off valves installed at the inlet and outlet of each heat pump unit, a main valve installed on the main supply and return water pipes of each area, a coordinated switching valve for switching the pipelines of switchable heat pump units, and a boiler switching valve for guiding the flow of boiler hot water. The flexible control system is configured to execute control methods, including a data acquisition and monitoring module for data acquisition and monitoring, a load forecasting module for load prediction, an equipment capacity calculation and matching module for equipment capacity calculation and matching, a collaborative control algorithm module for executing collaborative control algorithms, and a safety protection and fault handling module for safety protection and fault handling.

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