Central air conditioning chilled water system water supply temperature and pressure cooperative control method and system, medium

Abstract

The application discloses a chilled water supply temperature and pressure collaborative control method and system for a central air conditioner, a medium and belongs to the technical field of energy-saving control of a chilled water supply system of a central air conditioner. The method comprises the following steps: obtaining terminal operation data to construct a terminal state frame; generating a terminal thermal inertia margin record representing the energy-saving disturbance capacity of the terminal; identifying a terminal capacity gap and distinguishing the cause type of the temperature not reaching the set temperature; generating a dew point and dewing constraint boundary; generating a temperature and pressure collaborative control instruction under the joint constraint of the thermal inertia margin, the capacity gap and the dewing constraint boundary; issuing the control instruction to the corresponding controller, generating an execution effect verification record and updating the control template application weight. The application makes a collaborative decision on the chilled water supply temperature reset and the pressure difference reset, avoids the mutual offset of the temperature and pressure control actions, and considers the comfort, dehumidification safety and energy-saving control through the terminal thermal inertia margin evaluation, the capacity gap identification and the dewing risk pre-judgment.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving control technology for central air conditioning chilled water systems, and relates to HVAC, building automation, energy-saving control of central air conditioning chilled water systems, chiller group control, water pump frequency conversion control and terminal comfort control. Specifically, it is a method and system for coordinated control of water supply temperature and pressure in a central air conditioning chilled water system, and a medium. Background Technology

[0002] Large office buildings, commercial complexes, hospital outpatient buildings, and R&D buildings in industrial parks typically employ central air conditioning systems comprised of chillers, chilled water pumps, cooling water systems, air handling units, fan coil units, fresh air handling units, and building automation systems. Chilled water supply temperature and chilled water pressure differential are the two most critical setpoints for chilled water side operation. When the supply water temperature is too low, chiller energy consumption increases; when the pressure differential is too high, pump energy consumption increases, and some terminals may experience high flow rates with small temperature differences. Setting the supply water temperature or pressure differential too conservatively, while ensuring cooling at the terminals, will result in consistently high energy consumption.

[0003] Existing projects already incorporate numerous solutions for resetting chilled water supply temperature, resetting chilled water differential pressure, optimizing chiller group control, and load forecasting control based on outdoor weather conditions. For example, the system can adjust the chilled water supply temperature based on outdoor temperature, return water temperature, chiller load rate, or historical energy efficiency; it can also adjust the chilled water differential pressure based on the opening degree of the most unfavorable terminal valve, branch pressure differential, or pump frequency. While these solutions contribute to energy conservation, they still tend to cause mutual constraints and insufficient coordination in actual buildings.

[0004] In terms of publicly available technologies, ASHRAE Guideline 36-2018 and its supplementary publications disclose an engineering approach for trimming and responding to setpoints such as chilled water supply temperature and differential pressure based on terminal requests; patent CN101393570A describes simulation and control methods for central air conditioning operation, including increasing chilled water supply temperature, changing terminal valve opening, and controlling chilled water pumps based on the terminal differential pressure of the most unfavorable loop; and patent CN114576812A relates to variable flow control in a time-varying chilled water system, which adjusts the chilled water pump speed based on the branch supply and return water temperature difference, valve opening, and supply and return pipe pressure.

[0005] From an engineering constraint perspective, GB 50736-2012 "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" has already put forward design and operation requirements for air conditioning hot and cold water systems, detection and control, and radiant cooling anti-condensation. GB 50189-2015 "Standard for Energy Conservation Design of Public Buildings" and GB 55015-2021 "General Specification for Energy Conservation and Renewable Energy Utilization in Buildings" also constrain air conditioning water systems from the perspectives of energy conservation in public buildings, efficiency of cold and heat sources and distribution systems. Therefore, this invention uses conventional measurable objects such as temperature, humidity, dew point, valve opening, branch pressure difference, supply and return water temperature difference, and energy consumption, and takes safety protection, dehumidification, and condensation conditions as prerequisite constraints.

[0006] A common problem is that supply water temperature reset and differential pressure reset belong to different control logics. Supply water temperature control aims to raise the chilled water supply temperature as much as possible to improve chiller efficiency, while differential pressure control aims to reduce the water pump pressure difference as much as possible to reduce pump power. If the two logics only consider their respective indicators, it is possible that after the supply water temperature is increased, the terminal valves open wide across a large area, and the differential pressure control compensates by increasing the pressure; or after the differential pressure is reduced, the terminal valves remain close to fully open for a long time, and the supply water temperature control misinterprets that cooling is needed. The end result is that the control actions swing back and forth, and the energy-saving effect is unstable.

[0007] Another problem is that the actual tolerance of the terminals varies. The tolerance for temperature drift differs between inner-zone meeting rooms, outer-zone offices, corridors, unoccupied rooms, temporary high-traffic areas, and areas occupied for extended periods. Traditional controls typically use terminal valve openings or zone temperatures as instantaneous quantities, lacking data on how much temperature drift a particular terminal can withstand over a future observation window. Consequently, the system cannot determine which areas can withstand short-term adjustments in energy-saving directions and which areas are no longer suitable for continued operation.

[0008] Furthermore, high humidity conditions can lead to dew point and dehumidification issues. During the rainy season, after rain when it's muggy, when the fresh air humidity load is high, or when there is a high density of people, simply raising the chilled water supply temperature may weaken the dehumidification capacity of the surface cooler, resulting in increased indoor relative humidity, high supply air moisture content, or localized stuffiness. For non-drainage terminals such as chilled beams and radiant terminals, simply lowering the chilled water supply temperature may introduce condensation risks. If temperature reset only considers sensible thermal comfort or chiller efficiency without incorporating dew point boundaries into a unified constraint, situations may arise where users are hesitant to use the equipment, receive complaints after use, or require frequent manual maintenance. Summary of the Invention

[0009] To address the problems in existing central air conditioning chilled water systems, such as supply water temperature reset and differential pressure reset canceling each other out or compensating in reverse, lack of structured utilization of terminal thermal inertia, insufficient dehumidification boundary under high humidity conditions, difficulty in pre-judging the risk of condensation at non-drainage terminals, and lack of feedback on execution results, this invention provides a method, system, and medium for coordinated control of supply water temperature and pressure in central air conditioning chilled water systems.

[0010] According to one aspect of the present invention, a method for coordinated control of supply water temperature and pressure in a central air conditioning chilled water system is provided, comprising: S1, acquiring operating data of each terminal of the central air conditioning chilled water system and constructing a terminal status frame; S2, generating a terminal thermal inertia margin record based on the terminal status frame, wherein the thermal inertia margin record is used to characterize the available thermal inertia margin of each terminal within a future preset observation window; S3, identifying the terminal capacity gap of each terminal based on the terminal status frame and generating dew point and condensation constraint boundaries, wherein the terminal capacity gap is used to distinguish the cause type of failure to reach the set temperature, and the dew point and condensation constraint boundaries are used to generate... Before generating the temperature and pressure coordinated reset control command, it is determined whether the candidate temperature and pressure adjustment action exceeds the humidity, dehumidification, or condensation boundary; S4, based on the terminal thermal inertia margin record, the terminal capacity gap, and the dew point and condensation constraint boundary, a temperature and pressure coordinated reset control command is generated. The temperature and pressure coordinated reset control command includes at least the chilled water supply temperature adjustment amount and the chilled water pressure difference adjustment amount; S5, the temperature and pressure coordinated reset control command is sent to the corresponding controller, an execution effect verification record is generated in the preset observation window, and the terminal thermal inertia margin record and the applicable weight of the control template are updated according to the execution effect verification record.

[0011] Preferably, the terminal status frame includes indoor temperature, indoor relative humidity or indoor dew point, terminal valve opening, terminal air supply or fan status, coil supply and return water temperature difference or corresponding branch supply and return water temperature difference, branch pressure difference, occupancy status, set temperature, and data reliability; the thermal inertia margin record includes the temperature deviation of the corresponding terminal, temperature change direction, allowable drift, occupancy priority, and available thermal inertia margin; the execution effect verification record includes the average comfort deviation before and after the control command execution, maximum comfort deviation, number of terminals with saturated valve positions, number of terminals with high flow risk due to low temperature difference, chilled water supply and return water temperature difference, chiller power, water pump power, dew point and condensation constraint boundary status, manual connection mark, and reasons for not meeting expectations.

[0012] Preferably, for the i-th end, the thermal inertia margin B can be used. i Determine as follows: B i =H i -max(0,T) i -Tset i -E i )-k r ·max(0,R)i )·W i -k s Sat i Where i is the end number, H i The allowable drift amount is determined according to occupancy priority, in degrees Celsius; T i Indoor temperature; Tset i To set the temperature; E i The comfort dead zone, measured in degrees Celsius; R i The rate at which the indoor temperature changes in the direction of deviation from the set temperature, expressed in degrees Celsius per minute; W i For observation window duration; Sat i Valve position saturation; k r k represents the dimensionless trend weight. s The saturation deduction weight is applied to the Celsius dimension; the valve position saturation Sat i According to Sat i =G i ·min{1,max[0,(V i The formula is determined by V(-Vsat) / (100%-Vsat)]}, where V i G represents the opening degree of the end valve. i The saturated effective gate coefficient is the valve opening V at the end of the valve. i When the indoor temperature exceeds the saturation threshold Vsat and continues to reach the saturation hold time Lsat, and the indoor temperature does not converge to the set temperature while the data is reliable and valid, G i =1, otherwise G i =0; when the i-th end is a representative end set consisting of multiple valves, Sat i The average value of the saturation of each valve in the set is calculated by weighting the service area, design flow rate, or terminal priority.

[0013] Preferably, in S3, the terminal capacity gap includes at least one of the following: insufficient differential pressure, unsuitable chilled water supply temperature, insufficient air-side capacity, insufficient heat exchange, risk of large flow rate due to low temperature difference, abnormal measurement point, and sudden occupancy. Specifically, if the terminal valve opening exceeds the saturation threshold, the branch differential pressure is lower than the branch differential pressure requirement, and the supply and return water temperature difference does not exhibit a large flow rate due to low temperature difference, it is judged as insufficient differential pressure. If the terminal valve opening exceeds the saturation threshold, the branch differential pressure is greater than or equal to the branch differential pressure requirement, the air-side condition is normal, and the chilled water supply temperature is insufficient, the terminal capacity gap is not considered as insufficient differential pressure. If the chilled water supply temperature is higher than the temperature threshold, and the dew point and condensation constraint boundaries allow for cooling, it is judged as an unsuitable chilled water supply temperature type; if the fan is not running, the air volume is lower than the air volume threshold, the air valve opening is abnormal, or the filter pressure difference exceeds the preset pressure difference range, it is judged as an insufficient air-side capacity type; if the terminal valve opening exceeds the saturation threshold, and the coil supply and return water temperature difference is continuously lower than the preset percentage of the design temperature difference for more than a preset time, it is judged as a low temperature difference and large flow risk type; if the terminal valve opening exceeds the saturation threshold, and the branch pressure difference meets the branch pressure difference requirement. If the air-side condition is normal and the chilled water supply temperature is within the allowable range, but the supply and return water temperature difference of the coil, the outlet air temperature, or the heat exchange near-temperature difference does not reach the corresponding threshold within a preset time period, or there is evidence of at least one heat exchange-side abnormality such as coil blockage, valve bypass, filter blockage, or hydraulic imbalance, it is judged as insufficient heat exchange type; if the data reliability is lower than the reliability threshold, or at least one of the measured values ​​of indoor temperature and humidity, valve opening, branch pressure difference, and supply and return water temperature exceeds the physical reasonable range, remains unchanged for more than a preset time period, experiences instantaneous jumps exceeding the change threshold, contradicts adjacent measuring points, or contradicts valve command feedback, it is judged as measuring point abnormality type; if at least one of the occupancy status of personnel occupancy, room schedule, meeting reservation, access control or personnel statistics, carbon dioxide concentration, and fresh air load in the terminal service area changes from unoccupied to occupied within a preset time window, or the increase in the number of occupants or occupancy level exceeds the occupancy change threshold, or this causes the rate or magnitude of change of sensible heat or latent heat load within the preset observation time to exceed the change threshold and the indoor temperature has not yet completed the response, it is judged as occupancy sudden change type.

[0014] Preferably, in S3, the dew point and condensation constraint boundary includes a dehumidification capacity boundary and a condensation protection boundary; the dehumidification capacity boundary is: when the indoor dew point is higher than the target dew point, the indoor relative humidity is higher than the set humidity, or the air conditioning unit is in a dehumidification request state, the increase in chilled water supply temperature is limited and the preset observation window is shortened; the condensation protection boundary is: for non-drainage terminals, based on the indoor dew point Tdp, the safety margin Mdew, and the measured temperature of the terminal surface or the predicted temperature of the terminal surface Tsurf estimated from the supply water temperature, it is determined whether Tsurf is less than or equal to the sum of Tdp and Mdew; if it is less than or equal to, it is determined that there is a risk of condensation and the reduction of chilled water supply temperature is prohibited until at least one of the following operations is completed: increasing the fresh air dehumidification capacity, closing the relevant branch, or reducing the load, the execution conditions are reassessed.

[0015] Preferably, the temperature and pressure coordinated reset control command includes at least the chilled water supply temperature adjustment amount, chilled water differential pressure adjustment amount, applicable branch, applicable terminal set, execution order, maximum single-step adjustment range, observation window, prohibition condition, rollback condition, and cause code; wherein, if the available thermal inertia margin of multiple occupied terminals is greater than the set balance, the dew point and condensation constraint boundary are in an allowable state, the valve saturation is lower than the preset saturation threshold, and the supply and return water temperature difference is within the normal range, then an energy-saving direction control command is generated. The energy-saving direction control command includes raising the chilled water supply temperature by a preset amount while simultaneously reducing or maintaining the chilled water differential pressure; if there are fewer than a preset number of terminal valve saturation values ​​greater than or equal to the preset saturation threshold, then the terminal capacity gap type is determined: if the terminal capacity gap is a differential pressure deficiency type and the supply and return water temperature difference is normal, then a differential pressure compensation control command is output; if the terminal capacity gap is a low temperature difference and large flow risk type, then simple pressure increase is prohibited, and a check or conservative maintenance control command is output; if the supply water temperature reset and differential pressure reset directions are opposite, then a cause code is generated.

[0016] Preferably, the prohibition conditions in the temperature and pressure coordinated reset control command include at least one of the following: chiller low flow protection, chilled water pump minimum frequency, chiller minimum outlet water temperature, antifreeze protection, sensor offline, terminal valve abnormality, non-drainage terminal condensation risk, high humidity dehumidification request, and manual lockout. When any prohibition condition is met, no energy-saving direction control command exceeding the limit will be output; only confirmation, observation, conservative maintenance, or rollback control commands will be output.

[0017] Preferably, in S5, the applicable weights for updating the control template include: calculating the instruction verification score Y: Y = w1·C + w2·Vrelief + w3·ΔTrelief + w4·Esave - w5·Gpenalty; where C represents the degree to which the comfort deviation has not increased or has been improved, and Vrelief represents the degree of valve position saturation relief, determined according to the proportion of the total decrease in valve position saturation before and after execution, Vrelief = Σ i max(0, Sat) i,pre -Sat i,post ) / max(Σ i Sat i,pre , ε), where Sat i,pre Sat i,postThe values ​​are: valve saturation before and after execution; ε is a very small positive number to avoid a denominator of zero; Vrelief uses the reduction ratio of the number of saturated ends as a simplified value when only the number of saturated ends can be obtained; ΔTrelief represents the degree of improvement in the supply and return water temperature difference; Esave represents the degree of reduction in the combined energy consumption of chiller power and water pump power; Gpenalty represents the normalized penalty term formed by dew point exceeding the limit, humidity exceeding the limit, condensation risk, manual connection, and hard boundary contact; w1 to w5 are configurable weights. When Y is higher than the verification threshold and no comfort complaints, humidity exceeding the limit, condensation risk, valve saturation increase, or manual connection occurs within the preset observation window, the applicable weight of the corresponding control template is increased; when Y is lower than the verification threshold or a hard boundary contact occurs, the applicable weight of the corresponding control template is decreased and the reason for not achieving the expected result is recorded. The control template is a reusable control rule corresponding to the operating condition type, and the applicable weight of the control template is the confidence or priority of selecting the corresponding control template under this operating condition.

[0018] According to another aspect of the present invention, a coordinated control system for the temperature and pressure of the chilled water supply of a central air conditioning system is provided, based on the coordinated control method for the temperature and pressure of the chilled water supply of a central air conditioning system as described above, comprising: a terminal state frame construction module, used to acquire operating data of each terminal of the central air conditioning chilled water system and construct a terminal state frame; a terminal thermal inertia margin recording module, used to generate a terminal thermal inertia margin record based on the terminal state frame, the thermal inertia margin record being used to characterize the available thermal inertia margin of each terminal within a future preset observation window; a terminal capacity gap module, used to identify the terminal capacity gap of each terminal based on the terminal state frame, the terminal capacity gap being used to distinguish the cause type of failure to reach the set temperature; and a dew point and condensation constraint module, used to generate... The dew point and condensation constraint boundary are used to determine whether candidate temperature and pressure adjustment actions exceed humidity, dehumidification, or condensation boundaries before generating temperature and pressure coordinated reset control commands. The temperature and pressure coordinated reset control command module is used to generate temperature and pressure coordinated reset control commands based on the terminal thermal inertia margin record, the terminal capacity gap, and the dew point and condensation constraint boundary. The temperature and pressure coordinated reset control commands include at least the chilled water supply temperature adjustment and the chilled water pressure differential adjustment. The execution effect verification module is used to generate an execution effect verification record in a preset observation window after the temperature and pressure coordinated reset control command is issued to the corresponding controller, and to update the terminal thermal inertia margin record and the applicable weight of the control template based on the execution effect verification record.

[0019] According to another aspect of the present invention, a storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the central air conditioning chilled water system supply temperature and pressure coordinated control method as described above.

[0020] The beneficial effects of this invention are: 1. This invention integrates the reset of chilled water supply temperature and the reset of chilled water differential pressure into the same control command for coordinated decision-making, thereby reducing the mutual cancellation phenomenon of one logic raising the temperature and the other logic raising the pressure.

[0021] 2. By recording the available thermal inertia margin of each terminal, the unmanned area, low priority area and area with slow change can withstand smaller energy-saving disturbances, while high priority or already overheated areas are protected.

[0022] 3. Differentiate between insufficient differential pressure, unsuitable chilled water supply temperature, insufficient air supply, insufficient heat exchange of coils, and abnormal measuring points by identifying end-capacity gaps, so as to avoid treating all discomfort as simply lowering the water temperature or raising the differential pressure.

[0023] 4. By using dew point and condensation constraint boundaries, the dehumidification capacity and condensation protection are brought forward to before the control command is generated, effectively avoiding the safety risks induced by energy-saving control. It is especially suitable for working conditions that are easily ignored by ordinary temperature control, such as the plum rain season, high wind and humidity load, cold beams and radiant terminals.

[0024] 5. Record the execution results through the execution effect verification record, so that the energy-saving strategy is not only limited to the change of set value, but can continuously judge whether comfort, valve saturation, supply and return water temperature difference and energy consumption have been truly improved. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart of the overall process for the central air conditioning chilled water temperature and pressure coordinated reset control method of the present invention; Figure 2 This is a schematic diagram of the end-effector thermal inertia margin recording and end-effector capability gap generation of the present invention; Figure 3 This is a schematic diagram of the dew point and condensation constraint boundary of the present invention; Figure 4 This is a schematic diagram of the temperature and pressure coordinated reset control command and execution effect verification record of the present invention; Figure 5 This is a schematic diagram of the central air conditioning chilled water temperature and pressure coordinated reset control system of the present invention. Detailed Implementation

[0026] The present invention will be further described in conjunction with the accompanying drawings and specific embodiments. The following embodiments are used to illustrate the technical solutions of the present invention and do not limit the scope of protection of the present invention.

[0027] 1. Definitions: In this invention, the terminus / air conditioning terminal refers to the object that actually obtains cooling capacity from the chilled water system and serves a room, area or branch, such as the surface cooler of an air conditioning unit, fan coil unit, chilled beam, radiant terminal, fresh air handling unit with chilled water coil, or a representative set of terminals under a branch.

[0028] The temperature and pressure coordination in this invention refers to the simultaneous generation of the chilled water supply temperature setpoint and the chilled water pressure difference setpoint in the same round of judgment, rather than simply placing two existing controllers side by side.

[0029] 2. Project boundary description: The following temperature thresholds, humidity thresholds, valve position thresholds, observation windows, and adjustment ranges are engineering specifications for ease of understanding. Different buildings can be configured according to design parameters, terminal types, building automation point tables, operating strategies, and owner comfort standards. They do not constitute a limitation on the scope of protection.

[0030] In this invention, the valve position saturation threshold, comfort dead zone, allowable drift, dew point target, humidity threshold, single-step adjustment range, observation window, and verification threshold can all be set by the operating unit according to the building's purpose and design parameters. For areas with strict temperature and humidity requirements, such as hospital operating rooms, laboratories, data centers, museums, and archives, the occupancy priority can be set to high level or directly set to not participate in energy-saving directional control commands.

[0031] This invention does not require replacement of the existing local control loops of chillers, water pumps, air conditioning units, or fan coil units. Existing equipment continues to operate according to its safety protection, start-stop interlocks, PID control, and manufacturer-defined group control logic. This invention outputs upper-level setpoint adjustment control commands, limit suggestions, observation windows, and rollback conditions; it does not bypass antifreeze, condensation, low flow, compressor protection, or manual authorization.

[0032] This invention does not replace the equipment manufacturer's protection logic, nor does it bypass antifreeze, low flow, compressor protection, cold beam condensation protection, or manual locking. When data is unreliable, protection status is abnormal, or manual locking occurs, the system prioritizes outputting confirmation and conservative maintenance control commands.

[0033] 3. Overall Approach: The overall control approach of this invention is as follows: First, acquire the operating data to construct the end state frame; second, generate the end thermal inertia margin record and end capacity gap based on the end state frame; third, generate the dew point and condensation constraint boundary; then, generate the temperature and pressure coordinated reset control command under the joint constraints of the margin record, capacity gap and constraint boundary; after issuing the control command, generate the execution effect verification record in the observation window, and update the thermal inertia margin record and the applicable weight of the control template according to the verification result.

[0034] Specifically, this invention first organizes the terminal states into terminal state frames under the same time caliber, then uses the terminal thermal inertia margin record to quantify the short-term drift capacity that each region can withstand, then uses dew point and condensation constraint boundaries to constrain the candidate adjustments of water supply temperature and pressure difference, and finally issues them in the form of temperature and pressure coordinated reset control commands, and verifies whether energy saving is truly achieved and whether the comfort and dew point boundaries have been exceeded through execution effect verification records. This method does not adjust the water supply temperature setpoint alone, nor does it adjust the pressure difference setpoint alone according to the most unfavorable terminal valve opening, but rather organizes the terminal state, thermal inertia margin, capacity gap, dew point and condensation constraint boundaries, temperature and pressure coordinated adjustment, and execution effect verification into a continuous control chain.

[0035] The functional relationships of the above four core objects are as follows: End-point thermal inertia margin records are used to identify ends that can withstand energy-saving disturbances and ends that require protection; Dew point and condensation constraint boundaries are used to define the range of water temperature or differential pressure adjustments that are permissible under current humidity, dehumidification, and condensation conditions. The temperature and pressure coordinated reset control command is used to record the adjustment direction, adjustment range, observation window and rollback conditions of the water supply temperature and pressure difference within the current control cycle. The implementation effect verification record is used to determine whether the adjustment has reduced energy consumption and has not amplified comfort deviation, humidity risk or equipment boundary risk.

[0036] Example 1: A method for coordinated control of water supply temperature and pressure in a central air conditioning chilled water system.

[0037] Reference Figure 1 The method includes: Step 1, construct the end state frame; The terminal status frame is constructed by acquiring the operating data (such as set temperature, actual indoor temperature, wind speed, etc.) of each terminal of the central air conditioning chilled water system. It can be obtained from the building automation system, air conditioning unit controller, fan coil unit controller, branch differential pressure sensor, chilled water supply and return temperature sensor, chiller group control system and energy consumption metering system.

[0038] Data in the end-state frame is aligned using the same timestamp or the same sampling window, and data reliability is recorded to prevent a sensor from being used for decision-making when it is offline, stuck, or undergoes a significant change.

[0039] In this invention, the terminal status frame includes indoor status, terminal status, waterside status, occupancy status, and credibility. See Table 1 for details.

[0040] Table 1. Key fields of the end-state frame: Indoor status Indoor temperature, relative humidity, dew point, set temperature Determining comfort deviation and humidity boundary End state Valve opening degree, fan status, air supply status, supply and return water temperature difference of coil or branch line Identify valve saturation, insufficient airflow, and insufficient heat exchange. Waterside status Branch pressure differential, main supply and return water temperatures, chiller and pump status Determine if there is room for adjustment in water supply temperature and pressure differential. Occupied status Number of occupants, schedule, room priority, manual locking Determine the allowable drift amount and control command priority. Credibility Offline, frozen, jump, conflicting points Decide whether to enter the confirmation control command. The terminal status frame is the unified data entry point of this invention. One terminal status frame can correspond to an air conditioning unit, a fan coil unit, a cooling beam, a radiant terminal, a VAV reheat zone, or a representative set of terminals under a branch.

[0041] For each terminal, the terminal status frame preferably includes: indoor temperature T. i Set temperature Tset i Indoor relative humidity (RH) i or indoor dew point Tdp i End valve opening V i Fan or air supply status F i Coil water supply temperature Tws i , coil return water temperature Twr i Corresponding branch supply and return water temperatures, branch pressure difference DP β Occ status i Priority P i And data credibility Q i If some items are not arranged at the water temperature measurement point of each coil, the branch supply and return water temperature difference, the representative terminal temperature difference, or the heat exchange side index estimated by water volume and temperature can be used without affecting the implementation of the object chain of the present invention.

[0042] Data credibility Q i It is used to handle situations such as offline measurement points, long-term unchanged measurement points, sudden changes, conflicts with adjacent measurement points, and inconsistencies between valve commands and feedback. When Q i When the value is below the confidence threshold, the corresponding terminal does not directly participate in solving the control command for energy saving. Instead, it generates confirmation control commands, such as prompts to check the temperature and humidity sensor, valve actuator, or communication status.

[0043] Step 2: Generate the end thermal inertia margin record; Reference Figure 2 , Figure 2 This is a schematic diagram of the end-effector thermal inertia margin recording and end-effector capability gap generation of the present invention.

[0044] The terminal thermal inertia margin record is used to record the available thermal inertia margin of each terminal within a future observation window. To facilitate on-site implementation, this invention does not require the establishment of a complex building thermal network model. Instead, it uses interpretable margin indicators, such as engineering-obtainable temperature deviation, temperature change direction, occupancy status, allowable drift, valve saturation, observation window, and expected holding time, to comprehensively judge whether a terminal can still withstand small adjustments in energy-saving direction over a future period. For example, if the temperature in an unattended meeting room is close to the set value and the temperature change is gradual, it can be considered to still have a certain thermal inertia margin; if the temperature in a densely populated meeting room is already high, the valve is nearly fully open, and the temperature is still rising, then the thermal inertia margin is insufficient.

[0045] In this invention, for the i-th end, the thermal inertia margin B can be used. i Defined as: B i =H i -max(0,T) i -Tset i -E i )-k r ·max(0,R) i W i -k s Sat i ; Where i is the end number, H i The allowable drift amount is determined according to occupancy priority, H in densely populated or high-priority areas. i H in smaller, unoccupied, or low-priority areas i Larger; E i The comfort dead zone refers to the permissible range of room temperature fluctuation around the set temperature. Within this range, even if the room temperature deviates from the set temperature, the system does not consider comfort compromised and no control intervention is required; R i The rate at which indoor temperature changes in an uncomfortable direction (i.e., deviating from the set temperature) is typically understood as the rate of temperature increase during the cooling season and the rate of temperature decrease during the heating season; W i For observation window duration; Sat i Valve position saturation; k r and k s Configurable weights for the site.

[0046] Valve position saturation Sat i This value, ranging from 0 to 1, represents the saturation level of the valve at the i-th terminal. It is formed by two parts: first, determining whether the valve's high-open state is effective; then, calculating based on the extent to which the valve opening exceeds the saturation threshold. Preferably, Sat... i =G i ·min{1,max[0,(V i -Vsat) / (100%-Vsat)]};where G i Vsat is the saturation effective gate coefficient, and Vsat is the saturation threshold. When the valve opening V i The indoor temperature exceeds the saturation threshold Vsat and remains at saturation for a duration Lsat; the indoor temperature does not converge to the set temperature; and the data reliability Q is high. i When valid, G i =1, otherwise G i =0. If the i-th end corresponds to a single valve or a single coil, then Sat iThis indicates the saturation level of the valve or coil; if the i-th terminal corresponds to the representative terminal set under a branch, then Sat i The saturation of each valve can be weighted and averaged according to service area, design flow rate or terminal priority. Alternatively, in a simplified implementation, the proportion of valves in the set that exceed the saturation threshold can be used as the set saturation.

[0047] In the above formula, B i H i T i ,Tset i and E i The units are all in degrees Celsius, R i The unit is Celsius per minute, W i The unit is minutes, Sat i k is a dimensionless proportionality value. r The preferred weight is a dimensionless trend weight, k s The preferred method is a saturation deduction weight in Celsius. In engineering implementation, the comfort dead zone E... i The temperature can be between 0.5 degrees Celsius and 1.0 degrees Celsius, with the observation window W... i It can be taken from 5 to 30 minutes.

[0048] The meaning of this formula is: if a region is already too hot, the temperature is still rising, and the valve is close to being fully open, then its balance will be deducted, making it unsuitable as a target for energy-saving regulation.

[0049] When B i When the balance exceeds the preset threshold, it indicates sufficient balance, and the corresponding terminal can withstand a short-term, minor adjustment in the energy-saving direction. i When the balance is less than or equal to the preset balance threshold, it indicates that the balance is insufficient, and the corresponding terminal should not continue to undergo energy-saving direction adjustment (to protect the corresponding terminal). The preset balance threshold is also the applicable thermal inertia margin threshold, which can be a configurable value within the range of 0 degrees Celsius to 0.5 degrees Celsius.

[0050] The terminal thermal inertia margin record not only saves the current B i It also stores the impact of recent control commands on the terminal, such as whether the terminal complained, experienced valve saturation, or needed to revert after a water supply temperature increase. These records are used for subsequent adjustments to H. i Weights applicable to the observation window and control template.

[0051] Step 3: Identify end-capacity gaps; Terminal capacity gaps are used to determine why a certain area has not reached the set temperature, preventing the simplistic equation of high room temperature with insufficient cooling capacity and the resulting blind reduction of chilled water supply temperature, which could mask the actual problem. For example, if the terminal valve is open high, the room temperature does not drop, and the branch pressure differential is low, the pressure differential may be insufficient; if the valve is open high but the supply and return water temperature difference in the coil is very low, there may be a large flow rate due to a low temperature difference, insufficient heat exchange in the coil, or valve bypass; if the fan is not running or the filter is clogged, the air-side capacity is insufficient; if the temperature and humidity measurement data are unreliable, the measurement points should be verified first.

[0052] The present invention preferably classifies the terminal capacity gap into the following types: insufficient pressure difference, unsuitable chilled water supply temperature, insufficient wind side, insufficient heat exchange, high flow risk due to low temperature difference, abnormal measurement point, and sudden occupation.

[0053] The methods for identifying different types of capability gaps are as follows: Insufficient differential pressure type: When the opening degree V of the end valve is insufficient i High (exceeding the saturation threshold) and branch pressure difference DP β When the pressure difference is lower than the branch pressure difference requirement and the supply and return water temperature difference does not show a low temperature difference and large flow state, it should be judged as a pressure difference insufficiency type. Chilled water supply temperature inappropriate type: When V i When the temperature is too high (exceeding the saturation threshold), the branch pressure difference is sufficient (greater than or equal to the branch pressure difference requirement), the wind side condition is normal, but the water supply temperature is too high (above the temperature threshold) and the dew point and condensation constraint boundary allow for cooling, it can be judged as an unsuitable chilled water supply temperature. Insufficient airflow type: When the fan is not running, the air supply is insufficient (below the airflow threshold), the damper opening is abnormal, or the filter pressure difference is abnormal (exceeding the preset pressure difference range), it is judged as insufficient airflow type. Low temperature difference, large flow rate, high risk type: Calculate the supply and return water temperature difference ΔT of the coil. i =Twr i -Tws i (When there is no coil temperature difference measuring point, the supply and return water temperature difference of the corresponding branch can be used to represent the terminal temperature difference.) ΔT i The unit is degrees Celsius. If the opening degree V of the end valve... i High (exceeding the saturation threshold), but ΔT i If the temperature difference is consistently below 50% to 70% of the design temperature difference for an extended period (exceeding the preset duration), it indicates that further increasing the pressure difference may only increase the water volume without effectively improving heat exchange. This is identified as a low temperature difference and large flow rate risk type. Therefore, this invention restricts simple pressure increase control commands and prioritizes outputting coil, valve, filter, or hydraulic balance check prompts. Insufficient heat exchange type: when V i High (exceeding the saturation threshold), branch pressure difference DP βIf the branch pressure difference requirement is met, the fan or air supply status is normal and the chilled water supply temperature is within the allowable range, but the coil supply and return water temperature difference, air outlet temperature or heat exchange does not reach the corresponding threshold within the preset time, or there is evidence of abnormal heat exchange side such as coil blockage, valve bypass, filter blockage, hydraulic imbalance, etc., it is judged as insufficient heat exchange type. Measurement point anomaly type: when the data confidence level Q i If any of the measured values, such as indoor temperature and humidity, valve opening, branch pressure difference, supply and return water temperature, exceed the physically reasonable range, remain unchanged for a long time, change instantaneously beyond the change threshold, contradict adjacent measuring points, or contradict valve command feedback, it is judged as a measuring point abnormality. Occupancy mutation type: When the occupancy status changes abruptly, it is judged as occupancy mutation type. Occupancy status refers to the status of the area's usage intensity, such as personnel occupancy, room schedule, meeting reservation, access control or number of people, carbon dioxide concentration, and fresh air load. Mutation refers to the change from no one to someone within a preset time window, the increase in the number of people occupying or the increase in the occupancy level exceeding the occupancy change threshold, or the sudden increase in sensible heat or latent heat load (the rate of change / amplitude of change within the preset observation time exceeds the change threshold) and the indoor temperature has not yet completed the response.

[0054] Step 4: Generate dew point and condensation constraint boundaries; Reference Figure 3 , Figure 3 This is a schematic diagram of the dew point and condensation constraint boundary of the present invention.

[0055] Dew point and condensation constraint boundaries are a set of boundary judgments before the generation of control commands. They are used to determine whether candidate actions exceed humidity, dehumidification, or condensation boundaries before generating temperature and pressure coordinated reset control commands, rather than new valves, fittings, or sensors added on-site.

[0056] The dew point and condensation constraint boundaries include the dehumidification capacity boundary and the condensation protection boundary.

[0057] The dehumidification capacity boundary is used to handle high humidity conditions, primarily limiting the increase in chilled water supply temperature during periods of high humidity or dehumidification requests. For example, when the indoor dew point Tdp... i Above the target dew point, indoor relative humidity RH i When the humidity level exceeds the set value or the air conditioning unit has already requested dehumidification, the system restricts the increase of the chilled water supply temperature. This restriction does not absolutely prohibit the increase, but rather requires a smaller increase, a shorter observation window, and prioritizes differential pressure adjustment or branch adjustment that will not weaken the dehumidification capacity.

[0058] The condensation protection boundary is used to handle non-drainage terminals such as chilled beams, radiant ceilings, and radiant floors. It primarily limits further reduction of the chilled water supply temperature when there is a risk of condensation at these non-drainage terminals. For these non-drainage terminals, the system determines whether a candidate chilled water supply temperature could cause the terminal surface temperature to fall below the indoor dew point plus the safety margin, based on the indoor dew point (Tdp), the safety margin (Mdew), and the measured or estimated terminal surface temperature (Tsurf) from the supply water temperature. If Tsurf is less than or equal to the sum of Tdp and Mdew (i.e., Tsurf ≤ Tdp + Mdew), a condensation risk is identified, and the system prohibits further reduction of the chilled water supply temperature. Alternatively, it requires at least one of the following actions: increasing the fresh air dehumidification capacity, closing relevant branches, or reducing the load, before reassessing the execution conditions.

[0059] The safety margin (Mdew) within the condensation protection boundary can be taken as 0.5°C to 2.0°C. When there are non-drainage terminals such as cold beams, radiant ceilings, or radiant floors, it is advisable to determine the appropriate level based on the indoor dew point, surface temperature measurement points, or surface temperature estimated according to the water supply temperature. Dew point targets and humidity thresholds can be configured according to the building's purpose. For example, in ordinary comfort-air-conditioned areas, the upper limit of indoor relative humidity can be set at around 60%, or determined according to the operating unit's comfort standards, design documents, and building automation strategies.

[0060] Furthermore, dew point and condensation constraint boundaries can also include equipment protection boundaries and data trust boundaries to enhance the safety and reliability of system operation.

[0061] Equipment protection boundaries include the minimum chiller outlet water temperature, the maximum permissible chiller outlet water temperature, the minimum frequency of the chilled water pump, low flow protection for the chiller, antifreeze protection, and manual lockout status. These parameters together constitute the hard safety limits at the equipment level, ensuring that the system operates within a physically controllable range.

[0062] Data credibility boundaries include sensor offline status, sudden temperature and humidity fluctuations, contradictory valve command feedback, and abnormal branch pressure differences. When a data credibility boundary is triggered, the system prioritizes the confirmation process and will not make energy-saving adjustments exceeding the limit until the data is restored to credibility, in order to prevent erroneous operations based on unreliable data.

[0063] Among the aforementioned boundary protections, low flow protection for the chiller, antifreeze protection, manual locking, and large-scale sensor offline are considered hard prohibition conditions. Triggering any of these conditions will prevent the execution of energy-saving directional control commands exceeding the limit; the system will only output confirmation, observation, conservative maintenance, or rollback commands. High humidity dehumidification requests, some terminal units approaching the comfort boundary, and decreased reliability of data from individual terminals are considered limited observation conditions. The system allows for cautious execution of control actions while shortening the observation window and reducing the single-step adjustment amplitude, and continuously monitors the execution process. If the deteriorating trend does not improve, it will switch to a conservative maintenance or rollback strategy.

[0064] Step 5: Generate temperature and pressure coordinated reset control command; Reference Figure 4 , Figure 4 This is a schematic diagram of the temperature and pressure coordinated reset control command and execution effect verification record of the present invention.

[0065] The temperature and pressure coordinated reset control command is the core output object of this invention, used to specify the details of the current control action, including: the direction and magnitude of the rise and fall of the chilled water supply temperature, the direction and magnitude of the rise and fall of the chilled water pressure difference, the applicable branch and terminal set, the maximum single-step adjustment range, the observation window, the prohibition condition, the rollback condition, and the reason code. The temperature and pressure coordinated reset control command includes at least the following fields: command number, generation time, applicable branch, applicable terminal set, current value and adjustment amount of the chilled water supply temperature, current value and adjustment amount of the chilled water pressure difference, execution order, maximum single-step adjustment range, observation window, prohibition condition, rollback condition, and reason code.

[0066] In a preferred control logic, if the available thermal inertia margin Bᵢ at multiple occupied terminals is greater than the set balance, the dew point and condensation constraint boundaries are in an allowable state, the valve saturation is low, and the supply and return water temperature difference is within the normal range, the system generates an energy-saving directional control command, such as slightly increasing the chilled water supply temperature while simultaneously reducing or maintaining the chilled water pressure differential. Specifically, the single-step adjustment range of the supply water temperature can be 0.2 degrees Celsius to 1.0 degrees Celsius, the single-step adjustment range of the branch or main pipe pressure differential can be 2 kPa to 10 kPa, and the observation window can be 5 minutes to 30 minutes.

[0067] If a small number (less than the preset number) of terminal valve positions are saturated, the system will not immediately reduce the water supply temperature. Instead, it will first determine the type of capacity gap at that terminal: if the capacity gap indicates insufficient branch pressure difference and normal supply and return water temperature difference, the system will output a pressure difference compensation control command; if the capacity gap indicates a risk of low temperature difference and large flow, it will prohibit simple pressure increase and output a check or conservative maintenance control command.

[0068] If the high humidity dehumidification request is true, then raising the water supply temperature will be prohibited or restricted.

[0069] If the water supply temperature reset and differential pressure reset are in opposite directions (e.g., one is increased, and the other is decreased or maintained), the control command needs to provide a reason code to improve decision interpretability. For example, the reason code is defined as follows: The cause code TUP-DPKEEP indicates that when the terminal thermal inertia is sufficient (the available thermal inertia margin is greater than the set balance) and the dew point is permissible (the dew point and condensation constraint boundary are in the permissible state), the supply water temperature is increased and the pressure difference is maintained. The reason code TKEEP-DPUP indicates that the chilled water supply temperature will not be adjusted temporarily, and short-term pressure will be replenished for the most unfavorable branch (the branch with the lowest pressure difference and the largest opening of the terminal valve). The reason code TDOWN-DPKEEP indicates that the supply water temperature is reduced but the pressure is not increased when a high humidity dehumidification request is made or when the chilled water supply temperature is inappropriate. The reason code HOLD-CHECK indicates that the data is unreliable or the temperature difference is large, resulting in a high flow risk (exceeding the risk threshold). Confirm the issue first and do not make adjustments that exceed the limit.

[0070] The temperature and pressure coordinated reset control command includes at least one of the following prohibition conditions: chiller low flow protection, chilled water pump minimum frequency, chiller minimum outlet water temperature, antifreeze protection, sensor offline, terminal valve malfunction, risk of condensation at non-drainage terminals, high humidity dehumidification request, and manual lockout. When any of the above hard prohibition conditions are met, the system will not output energy-saving directional control commands exceeding the limit, but will only output confirmation, observation, conservative maintenance, or rollback control commands. This mechanism ensures that the energy-saving control strategy of this invention is executed within the equipment safety permission range, without bypassing the underlying protection logic such as chiller units, chilled water pumps, antifreeze, condensation, and manual lockout.

[0071] Step 6: Generate execution effect verification record; After the temperature and pressure coordinated reset control command is executed, the system generates an execution effect verification record in the observation window. The verification record quantitatively evaluates the control effect by comparing the comfort deviation, number of valve-saturated terminals, risk of large flow rate due to low temperature difference, supply and return water temperature difference, chiller power, pump power, and dew point and condensation constraint status before and after the control command execution. The verification record at least records the average comfort deviation, maximum comfort deviation, number of valve-saturated terminals, number of terminals with large flow rate risk due to low temperature difference, chilled water supply and return water temperature difference, chiller power, pump power, dew point and condensation constraint status, manual connection mark, and reasons for not meeting expectations before and after execution. If the control command achieves energy-saving effects and does not cause comfort deterioration or humidity problems, the applicable weight of the corresponding control template is increased; if it does not meet expectations, the reason for failure is recorded and the weight of the corresponding template is reduced. Furthermore, the execution effect verification record will be fed back into the calculation of thermal inertia margin, used for dynamic calibration and correction of the available thermal inertia margin value and corresponding calculation parameters required for the next round of decision-making.

[0072] This invention defines a command verification score Y, which is used to evaluate the execution results of control commands in terms of comfort, valve position, temperature difference, energy consumption, and constraint boundaries. Y=w1·C+w2·Vrelief+w3·ΔTrelief+w4·Esave-w5·Gpenalty; Where C represents the degree to which the comfort deviation is not amplified or is improved, that is, the improvement of the room temperature deviation from the set temperature. C = (comfort deviation before execution - comfort deviation after execution) / comfort deviation before execution; Vrelief represents the degree of relief from valve position saturation, and is preferably determined by the proportion of the decrease in the total valve position saturation before and after execution. Vrelief = Σ i max(0, Sat) i,pre -Sat i,post ) / max(Σ i Sat i,pre , ε), where Sat i,pre Sat i,post Vrelief represents the valve saturation before and after execution, respectively, and ε is a very small positive number to avoid the denominator being zero. This definition reflects both the reduction in the number of saturated ends and the decrease in the degree of valve saturation. In a simplified implementation where only the number of saturated ends can be obtained, Vrelief can be degenerated into Vrelief = (number of saturated ends before execution - number of saturated ends after execution) / number of saturated ends before execution. ΔTrelief represents the degree of improvement in the supply and return water temperature difference, that is, the extent to which the supply and return water temperature difference approaches the set value. ΔTrelief = (temperature difference after execution - temperature difference before execution) / (set temperature difference - temperature difference before execution). Esave represents the degree of reduction in combined energy consumption of chiller power and water pump power. Esave = (Total power before execution - Total power after execution) / Total power before execution. Gpenalty represents the normalized penalty term for constraint boundaries and manual intervention. Sources include dew point exceeding limits, humidity exceeding limits, condensation risk, manual intervention, and violation of hard prohibition conditions. After weighting, it is limited to 0 to 1 and can be determined according to Gpenalty=min{1,λ1·Ddew+λ2·Drh+λ3·Icond+λ4·Imanual+λ5·Ihard}; where Ddew is the normalized degree of dew point exceeding the target dew point or dew point boundary, Drh is the normalized degree of indoor relative humidity exceeding the humidity threshold, Icond indicates whether condensation risk occurs, Imanual indicates whether manual intervention occurs, Ihard indicates whether hard prohibition conditions are violated, and λ1 to λ5 are the penalty weights. w1 to w5 are the on-site configurable weights.

[0073] The above-mentioned C, Vrelief, ΔTrelief, Esave, and Gpenalty are all dimensionless evaluation quantities between 0 and 1. Among them, C, ΔTrelief, and Esave can be normalized by dividing the difference before and after execution by the baseline or target difference before execution, while Gpenalty is weighted and normalized by boundary out-of-bounds quantities and event flags. Y is a dimensionless comprehensive score. This score is used to evaluate whether the control command achieves the expected result and is not used as a direct control formula for the underlying equipment.

[0074] If Y is higher than the verification threshold, and no comfort complaints, humidity exceeding the limit, condensation risk, valve saturation increase, or manual intervention occur within the observation window, then the applicable weight of the corresponding control template is increased; if Y is lower than the verification threshold or a hard boundary is touched, then the applicable weight of the corresponding control template is decreased and the reason for not achieving the expected result is recorded.

[0075] The control template is a reusable temperature and pressure coordinated control rule preset or modified through historical operation for a certain type of operating condition. It includes at least the applicable conditions, water supply temperature action, differential pressure action, single-step limit, observation window, prohibition conditions, rollback conditions, and reason code. The applicable conditions are used to determine whether the current operating condition matches the control template. The applicable weight of the control template indicates the confidence or priority of using the template in subsequent similar operating conditions. This weight is dynamically adjusted according to the execution effect verification score. A higher verification score increases the weight, and vice versa. The reasons for not meeting the expectations are recorded to continuously optimize control decisions. The rollback condition refers to the pre-set condition used to determine whether the current control action should be canceled or rolled back to the previous safe state. In the temperature and pressure coordinated reset control command, the triggering factors for the rollback condition include, but are not limited to, an increase in valve saturation, an increase in humidity, dew point touch (exceeding the limit), manual intervention, or prohibition conditions. The hard boundary refers to the safety, protection, or physical constraints in the system that cannot be violated, namely, the prohibition conditions listed in Section VI, Temperature and Pressure Coordinated Reset Control Command. Hard boundary touch means that any prohibition condition is met.

[0076] This invention integrates water supply temperature and pressure differential into a single control command for joint decision-making, overcoming the problem of "cooling commands and pressurization commands canceling each other out" in traditional separate control systems. Through terminal thermal inertia margin assessment, it protects high-priority or already overheated areas while tapping into the energy-saving potential of low-priority, low-load areas. By classifying terminal capacity gaps, it accurately identifies the causes of discomfort, avoiding blind cooling or pressurization and reducing misoperation and ineffective energy consumption. By pre-positioning dew point and condensation protection at the decision-making stage, it effectively avoids safety risks induced by energy-saving control. By integrating the above mechanisms with closed-loop verification of execution effects, it achieves refined and adaptive energy-saving control of the chilled water system.

[0077] Example 2: A coordinated control system for temperature and pressure of chilled water supply in a central air conditioning chilled water system.

[0078] Based on the overall concept of Embodiment 1 above, this embodiment provides a central air conditioning chilled water system supply temperature and pressure coordinated control system to implement the above embodiments and preferred embodiments. Details that have been described will not be repeated.

[0079] Reference Figure 5 , Figure 5 This is a schematic diagram of the central air conditioning chilled water temperature and pressure coordinated reset control system of the present invention, as shown below. Figure 5 As shown, the system includes: The terminal status frame construction module is used to acquire the operating data of each terminal of the central air conditioning chilled water system (such as terminal controllers, air conditioning units, fan coil units, cooling beams, radiant terminals, branch differential pressure sensors, main supply and return water temperatures, chillers, water pumps, etc.). After preprocessing, the terminal status frame is constructed. The preprocessing operations include sampling alignment (time synchronization, unifying the time base), anomaly cleaning (removing outliers), and credibility judgment (comprehensively evaluating and quantifying the data quality in terms of completeness, consistency, timeliness, accuracy, and validity). The end thermal inertia margin recording module is used to generate thermal inertia margin records for each end based on the end state frame. The thermal inertia margin records are used to characterize the available thermal inertia margin of each end within a future preset observation window. The end capability gap module is used to identify the end capability gap of each end based on the end status frame. The end capability gap is used to distinguish the cause of the failure to reach the set temperature. The dew point and condensation constraint module is used to generate dew point and condensation constraint boundaries. The dew point and condensation constraint boundaries are used to determine whether the candidate temperature and pressure adjustment action crosses the humidity, dehumidification or condensation boundary before generating the temperature and pressure coordinated reset control command. The temperature and pressure coordinated reset control command module is used to generate temperature and pressure coordinated reset control commands based on the terminal thermal inertia margin record, the terminal capacity gap and the dew point and condensation constraint boundary. The temperature and pressure coordinated reset control commands include at least the chilled water supply temperature adjustment amount and the chilled water pressure difference adjustment amount. The execution effect verification module is used to generate an execution effect verification record in a preset observation window after the temperature and pressure coordinated reset control command is sent to the corresponding controller, and update the end thermal inertia margin record and the applicable weight of the control template according to the execution effect verification record. At the same time, the constraint boundary statistics are also updated synchronously to provide a basis for the boundary conditions of subsequent control cycles. It also includes a verification record library, a control template library, and interfaces with building automation systems, chiller group controllers, chilled water pump controllers, and branch differential pressure controllers.

[0080] Each module can be deployed in a building automation server, energy management platform, chiller plant group control platform, or edge controller. For buildings with existing building automation systems, this invention mainly adds logic for organizing higher-level objects, generating control commands, determining boundaries, and writing back verification records, without requiring replacement of field terminals and chiller hardware.

[0081] Application Example 1: Morning rush hour in an office building.

[0082] After the morning rush hour, staff gradually arrived at their posts in the inner areas of an office building, and some meeting rooms began to be used. While the outer areas were affected by solar radiation, the room temperature was not yet high. After collecting end-point status frames, the system found that most areas B were unoccupied or had low occupancy.i The space is relatively high, but both meeting rooms B are spacious. i The humidity is low and the valve opening is increasing. The dew point and condensation constraint boundaries indicate normal humidity, and the dehumidification request is not strong. Instead of directly raising the water supply temperature across the entire building, the system generates a branch-level temperature and pressure coordinated reset control command: slightly raising the water supply temperature and lowering the differential pressure for the low-occupancy branch, maintaining the water supply temperature and differential pressure for the branch containing the conference room, and setting a shorter observation window. After execution, if the comfort deviation in the low-occupancy branch does not increase and the pump power decreases, the execution effect verification record increases the applicable weight of this type of control template.

[0083] Application Example 2: High humidity during the plum rain season.

[0084] During the rainy season, the indoor relative humidity in a commercial complex is high, and the fresh air unit is in dehumidification request mode. Traditional energy-saving strategies may raise the chilled water supply temperature when the room temperature is close to the set value. In this invention, the dew point and condensation constraint boundary identify that the indoor dew point is higher than the target dew point, and the high humidity dehumidification request is established. Therefore, the temperature and pressure coordinated reset control command prohibits raising the supply water temperature, and only allows small differential pressure adjustments or maintenance on branches that do not increase the humidity risk. If the humidity recovers in the observation window and the valve position is not saturated, the system gradually increases the supply water temperature adjustment range.

[0085] Application Example 3: Low temperature difference and large flow rate.

[0086] A valve at the end of a certain floor is consistently open at a high position, but the temperature difference between the supply and return water in the coil is low, and the water pump frequency is also high. If the pressure difference is adjusted only by opening the valve to its maximum position, the system will continue to pressurize, leading to even higher pump energy consumption. This invention identifies this end-point as a high-flow-rate, low-temperature-difference risk area by identifying a capacity gap at the end point, limiting simple pressure-boosting control commands and outputting confirmation control commands to check the coil filter, valve bypass, hydraulic balance, and air-side status. If the supply and return water temperature difference recovers after confirmation, normal temperature and pressure coordinated reset is then implemented.

[0087] Application Example 4: Condensation protection for cold beams or radiant ends.

[0088] In a certain office area, chilled beams or radiant ceiling panels are used as non-drainage terminals. In the afternoon, localized areas experience higher temperatures. If only room temperature and valve opening are considered, the system might tend to lower the chilled water supply temperature. In this invention, the dew point and condensation constraint boundaries are first read from the indoor dew point, relative humidity, and non-drainage terminal type for that area. The condensation risk is then assessed by combining the terminal surface temperature measurement points or the predicted surface temperature estimated from the supply water temperature. If the predicted surface temperature is lower than the indoor dew point plus a safety margin, the temperature and pressure coordinated reset control command does not allow further reduction in the supply water temperature. Instead, it outputs conservative actions such as increasing the fresh air dehumidification capacity, limiting related branches, maintaining or slightly adjusting the pressure difference, and extending the observation window. This avoids pushing non-drainage terminals into a condensation risk trap for short-term cooling.

[0089] The present invention also provides a storage medium storing a computer program, wherein the computer program is configured to execute the steps in the above method embodiments when running.

[0090] Optionally, in this embodiment, the storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0091] The sequence numbers of the above embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The descriptions of each embodiment in the above embodiments have different emphases; for parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0092] In the embodiments provided above, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or unit components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between units or modules, and may be electrical or other forms.

[0093] If the integrated module is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for coordinated control of temperature and pressure in the chilled water supply of a central air conditioning system, characterized in that, include: S1, acquire the operating data of each terminal of the central air conditioning chilled water system, and construct the terminal status frame; S2, Based on the end state frame, generate an end thermal inertia margin record, the thermal inertia margin record being used to characterize the available thermal inertia margin of each end within a future preset observation window; S3. Based on the terminal status frame, identify the terminal capability gap of each terminal and generate dew point and condensation constraint boundary. The terminal capability gap is used to distinguish the cause of failure to reach the set temperature. The dew point and condensation constraint boundary are used to determine whether the candidate temperature and pressure adjustment action crosses the humidity, dehumidification or condensation boundary before generating the temperature and pressure coordinated reset control command. S4. Based on the joint constraints of the terminal thermal inertia margin record, the terminal capacity gap and the dew point and condensation constraint boundary, a temperature and pressure coordinated reset control command is generated. The temperature and pressure coordinated reset control command includes at least the chilled water supply temperature adjustment amount and the chilled water pressure difference adjustment amount. S5, the temperature and pressure coordinated reset control command is sent to the corresponding controller, an execution effect verification record is generated in the preset observation window, and the end thermal inertia margin record and the applicable weight of the control template are updated according to the execution effect verification record.

2. The method for coordinated control of temperature and pressure in the chilled water supply system of a central air conditioning system according to claim 1, characterized in that, The terminal status frame includes indoor temperature, indoor relative humidity or indoor dew point, terminal valve opening, terminal air supply or fan status, coil supply and return water temperature difference or corresponding branch supply and return water temperature difference, branch pressure difference, occupancy status, set temperature and data reliability. The thermal inertia margin record includes the temperature deviation at the corresponding end, the direction of temperature change, the allowable drift, the occupancy priority, and the available thermal inertia margin; The execution effect verification record includes the average comfort deviation, maximum comfort deviation, number of valve saturation terminals, number of terminals with high flow risk due to low temperature difference, chilled water supply and return temperature difference, chiller power, water pump power, dew point and condensation constraint boundary status, manual connection mark, and reasons for not meeting expectations before and after the execution of the control command.

3. The method for coordinated control of water supply temperature and pressure in a central air conditioning chilled water system according to claim 1, characterized in that, For the i-th end, the thermal inertia margin B can be used. i Determine as follows: B i =H i -max(0,T) i -Tset i -E i )-k r ·max(0,R) i )·W i -k s Sat i Where i is the end number, H i The allowable drift amount is determined according to occupancy priority, in degrees Celsius; T i Indoor temperature; Tset i To set the temperature; E i The comfort dead zone, measured in degrees Celsius; R i The rate at which the indoor temperature changes in the direction of deviation from the set temperature, expressed in degrees Celsius per minute; W i For observation window duration; Sat i Valve position saturation; k r k represents the dimensionless trend weight. s Saturation deduction weight for Celsius units; The valve position saturation Sat i According to Sat i =G i ·min{1,max[0,(V i The formula is determined by V(-Vsat) / (100%-Vsat)]}, where V i G represents the opening degree of the end valve. i The saturated effective gate coefficient is the valve opening V at the end of the valve. i When the indoor temperature exceeds the saturation threshold Vsat and continues to reach the saturation hold time Lsat, and the indoor temperature does not converge to the set temperature while the data is reliable and valid, G i =1, otherwise G i =0; when the i-th end is a representative end set consisting of multiple valves, Sat i The average value of the saturation of each valve in the set is calculated by weighting the service area, design flow rate, or terminal priority.

4. The method for coordinated control of temperature and pressure in the chilled water supply system of a central air conditioning system according to claim 1, characterized in that, In S3, the terminal capacity gap includes at least one of the following: insufficient pressure difference, unsuitable chilled water supply temperature, insufficient wind-side capacity, insufficient heat exchange, risk of large flow rate due to low temperature difference, abnormal measurement point, and sudden occupation. Among them, if the opening degree of the terminal valve exceeds the saturation threshold, the branch pressure difference is lower than the branch pressure difference requirement, and the supply and return water temperature difference does not show a low temperature difference and large flow state, it is judged as a pressure difference insufficient type. If the opening of the terminal valve exceeds the saturation threshold, the branch pressure difference is greater than or equal to the branch pressure difference requirement, the wind side condition is normal, the chilled water supply temperature is higher than the temperature threshold, and the dew point and condensation constraint boundary allow for cooling, it is judged as an unsuitable chilled water supply temperature type. If the fan is not running, the air volume is lower than the air volume threshold, the air valve opening is abnormal, or the filter pressure difference exceeds the preset pressure difference range, it is judged as insufficient air-side capacity. If the opening of the terminal valve exceeds the saturation threshold and the temperature difference between the supply and return water of the coil remains lower than the preset percentage of the design temperature difference for a period of time, it is judged as a high-flow-rate low-temperature-difference-risk type. If the opening of the terminal valve exceeds the saturation threshold, the branch pressure difference meets the branch pressure difference requirement, the air side condition is normal and the chilled water supply temperature is within the allowable range, but the coil supply and return water temperature difference, the outlet air temperature or the heat exchange near temperature difference does not reach the corresponding threshold within the preset time, or there is evidence of at least one heat exchange side abnormality such as coil blockage, valve bypass, filter blockage, or hydraulic imbalance, it is judged as insufficient heat exchange type. If the data reliability is lower than the reliability threshold, or if at least one of the measured values ​​of indoor temperature and humidity, valve opening, branch pressure difference, and supply and return water temperature exceeds the physical reasonable range, remains unchanged for more than the preset time, changes instantaneously beyond the change threshold, contradicts adjacent measuring points, or contradicts valve command feedback, it is judged as a measuring point abnormality. If at least one of the following occupancy statuses in the end-service area changes from unoccupied to occupied within a preset time window, or if the increase in the number of occupants or the occupancy level exceeds the occupancy change threshold, or if this causes the rate or magnitude of change of sensible or latent heat load to exceed the change threshold within a preset observation time and the indoor temperature has not yet completed its response, it is judged as an occupancy mutation.

5. The method for coordinated control of water supply temperature and pressure in a central air conditioning chilled water system according to claim 1, characterized in that, In S3, the dew point and condensation constraint boundary includes a dehumidification capacity boundary and a condensation protection boundary; The dehumidification capacity boundary is: when the indoor dew point is higher than the target dew point, the indoor relative humidity is higher than the set humidity, or the air conditioning unit is in a dehumidification request state, the increase in the chilled water supply temperature is limited and the preset observation window is shortened. The condensation protection boundary is as follows: For non-drainage terminals, based on the indoor dew point Tdp, safety margin Mdew, and the measured terminal surface temperature or the predicted terminal surface temperature Tsurf estimated from the supply water temperature, it is determined whether Tsurf is less than or equal to the sum of Tdp and Mdew; if it is less than or equal to, it is determined that there is a risk of condensation and the reduction of the chilled water supply temperature is prohibited until at least one of the following operations is completed: improving the fresh air dehumidification capacity, closing the relevant branch, or reducing the load, the execution conditions are reassessed.

6. The method for coordinated control of water supply temperature and pressure in a central air conditioning chilled water system according to claim 1, characterized in that, In S4, the temperature and pressure coordinated reset control command includes at least the chilled water supply temperature adjustment amount, chilled water pressure differential adjustment amount, applicable branch, applicable terminal set, execution order, maximum single-step adjustment range, observation window, prohibition condition, rollback condition, and reason code. If the available thermal inertia margin of multiple occupied terminals is greater than the set balance, the dew point and condensation constraint boundary are in an allowable state, the valve position saturation is lower than the preset saturation threshold, and the supply and return water temperature difference is within the normal range, then an energy-saving directional control command is generated. The energy-saving directional control command includes raising the chilled water supply temperature by a preset amount while simultaneously reducing or maintaining the chilled water pressure difference. If there are fewer than the preset number of terminal valve positions with saturation greater than or equal to the preset saturation threshold, then determine the type of terminal capacity gap: if the terminal capacity gap is of the differential pressure insufficient type and the supply and return water temperature difference is normal, then output a differential pressure compensation control command; if the terminal capacity gap is of the low temperature difference and large flow risk type, then prohibit simple pressure increase and output a check or conservative maintenance control command. If the water supply temperature reset and differential pressure reset are in opposite directions, a reason code will be generated.

7. The method for coordinated control of water supply temperature and pressure in a central air conditioning chilled water system according to claim 6, characterized in that, The prohibited conditions in the temperature and pressure coordinated reset control command include at least one of the following: chiller low flow protection, chilled water pump minimum frequency, chiller minimum outlet water temperature, antifreeze protection, sensor offline, terminal valve abnormality, non-drainage terminal condensation risk, high humidity dehumidification request, and manual lockout. When any prohibition condition is met, no energy-saving direction control command exceeding the limit will be output; only confirmation, observation, conservative maintenance, or rollback control commands will be output.

8. The method for coordinated control of temperature and pressure in the chilled water supply system of a central air conditioning system according to claim 1, characterized in that, In S5, the weights applicable to updating the control template include: Calculate the instruction verification score Y: Y = w1·C + w2·Vrelief + w3·ΔTrelief + w4·Esave - w5·Gpenalty; where C represents the degree to which the comfort deviation has not increased or has been improved, and Vrelief represents the degree of relief of valve saturation, determined according to the proportion of the total decrease in valve saturation before and after execution, Vrelief = Σ i max(0, Sat) i,pre -Sat i,post ) / max(Σ i Sat i,pre , ε), where Sat i,pre Sat i,post These represent the valve position saturation before and after execution, respectively. ε is a very small positive number to avoid the denominator being zero. When only the number of saturated ends can be obtained, Vrelief uses the reduction ratio of the number of saturated ends as a simplified value. ΔTrelief represents the degree of improvement in the supply and return water temperature difference. Esave represents the degree of reduction in the combined energy consumption of chiller power and water pump power. Gpenalty represents the normalized penalty term formed by dew point exceeding the limit, humidity exceeding the limit, condensation risk, manual connection and hard boundary contact. w1 to w5 are configurable weights. When Y is higher than the verification threshold and no comfort complaints, humidity exceeding the limit, condensation risk, valve saturation increase, or manual intervention occur within the preset observation window, the applicable weight of the corresponding control template is increased; when Y is lower than the verification threshold or a hard boundary is touched, the applicable weight of the corresponding control template is decreased and the reason for not achieving the expected result is recorded. The control template is a reusable control rule corresponding to the working condition type, and the applicable weight of the control template is the confidence level or priority of selecting the corresponding control template under this working condition.

9. A coordinated control system for temperature and pressure of chilled water supply in a central air conditioning system, based on the coordinated control method for temperature and pressure of chilled water supply in a central air conditioning system according to any one of claims 1 to 8, characterized in that, include: The terminal status frame construction module is used to acquire the operating data of each terminal of the central air conditioning chilled water system and construct the terminal status frame. The end thermal inertia margin recording module is used to generate an end thermal inertia margin record based on the end state frame. The thermal inertia margin record is used to characterize the available thermal inertia margin of each end within a future preset observation window. The end capability gap module is used to identify the end capability gap of each end based on the end status frame. The end capability gap is used to distinguish the cause of the failure to reach the set temperature. The dew point and condensation constraint module is used to generate dew point and condensation constraint boundaries. The dew point and condensation constraint boundaries are used to determine whether the candidate temperature and pressure adjustment action crosses the humidity, dehumidification or condensation boundary before generating the temperature and pressure coordinated reset control command. The temperature and pressure coordinated reset control command module is used to generate temperature and pressure coordinated reset control commands based on the terminal thermal inertia margin record, the terminal capacity gap and the dew point and condensation constraint boundary. The temperature and pressure coordinated reset control commands include at least the chilled water supply temperature adjustment amount and the chilled water pressure difference adjustment amount. The execution effect verification module is used to generate an execution effect verification record in a preset observation window after the temperature and pressure coordinated reset control command is sent to the corresponding controller, and to update the end thermal inertia margin record and the applicable weight of the control template according to the execution effect verification record.

10. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the central air conditioning chilled water system supply temperature and pressure coordinated control method as described in any one of claims 1 to 8.

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