Dew-point temperature-based purification air conditioning seasonal differentiation energy-saving control method and system

Abstract

The application discloses a purification air conditioner seasonal differentiation energy-saving control method and system based on old purification air cabinet reconstruction. The reconstruction object is a purification air cabinet, fresh air pipe, return air pipe and air outlet pipe; an independent dehumidification module is embedded in the purification air cabinet, an independent humidification module is externally connected to the fresh air pipe, and a separate decoupling circuit and an interlocking relay are arranged. Total dehumidification and total humidification working conditions are divided according to the outdoor dew point as the only criterion, the independent dehumidification and humidification control circuits in the purification subsystem are physically independent, not coupled, and strictly mutually exclusive in dehumidification and humidification. In summer, two-stage cold quantity division and self-produced reheat replace electric reheat, and in winter, step heating and waste heat isohumidification. The original electric heating, cold water coil and electrode humidifier are downgraded to serve as peak shaving. The dew point criterion, double-module independent differentiation and strict mutual exclusion of dehumidification and humidification are indivisible. The interface energy consumption of the purification unit is reduced by 88% to 92%, and the overall energy consumption of the heating and ventilation system is reduced by 63% to 67%.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving control technology for building HVAC systems, specifically relating to a seasonally differentiated energy-saving control method and system for cleanroom air conditioning based on dew point temperature, which is particularly suitable for the renovation of old cleanroom air conditioning subsystems in places such as hospitals and cleanrooms. Background Technology

[0002] Cleanroom air conditioning subsystems in hospitals, cleanrooms, and other similar facilities typically serve clean areas such as operating rooms, ICUs, and laboratories. These systems are highly sensitive to both temperature and humidity, requiring precise temperature control of 22-26℃ and relative humidity of 40-60%. (The temperature and humidity ranges for clean areas described in this invention are general guidelines; specific projects should select sub-ranges according to local hospital / industry cleanroom regulations. For example, the cleanroom areas in Foshan, which this invention serves, are narrowed down to 22-26℃ and 50-60% relative humidity according to local hospital cleanroom regulations; all data cited below are based on this sub-range. This invention protects the control method itself and is not limited by specific sub-range values.) Boundary Declaration of the Modification Scope: The modification scope described in this invention is strictly limited to the cleanroom air conditioning subsystem and its external interfaces. Non-cleanroom terminals and their control strategies, water temperature settings, and differentiated cooling / heating control are not within the scope of this invention.

[0003] Scenario for Renovation: Many hospitals and other cleanrooms in my country, built around 2010, still rely on outdated air conditioning units to maintain temperature and humidity in critical clean areas such as operating rooms, ICUs, supply rooms, endoscopy centers, neonatal wards, and delivery rooms. These older cleanroom air handling units, according to engineering topology definitions, only serve the cleanroom area—providing clean air to the cleanroom area via coarse, pre-, and medium-efficiency filters and a final high-efficiency filter (i.e., "independent air supply duct for the cleanroom area," hereinafter the same), without supplying air to spaces outside the cleanroom area. The cleanroom air handling unit has three external interfaces: ① Fresh air duct (directly connected to the outside, introducing fresh outdoor air); ② Return air duct (cleanroom area → air handling unit, introducing return air from the cleanroom area); ③ Exhaust air duct (air handling unit → cleanroom area, supplying clean air to the cleanroom area); Exhaust air volume = Fresh air volume + Return air volume. The old air handling units and their associated central air conditioning systems generally have the following structural and operational characteristics: (1) Cooling and dehumidifying the air with chilled water coils, humidifying with electrode humidifiers, and reheating the air after condensation and dehumidification with electric heating; (2) The control system mostly uses the relative humidity threshold of the return air for humidity control, while relative humidity is closely related to temperature, and there is a natural delay in the operation of temperature and humidity control and online monitoring; therefore, the coupling of temperature and humidity control is specifically reflected in the internal friction condition that is easy to occur in winter when humidification and dehumidification alternate in a short period of time, and the internal friction condition of cold and heat when the chilled water proportional integral valve is fully open and the electric heating is fully open in summer; (3) The chilled water of the chilled water coil comes from the central air conditioning host or the dedicated air-cooled module host in summer and from the dedicated air-cooled module host in winter. Because dehumidification requires a lower temperature of chilled water, the overall chilled water temperature of the central air conditioning system is low in summer and chilled water also needs to be supplied in winter. (4) The humidification of the electrode humidifier and the reheating of the air after condensation and dehumidification by electric heating are both low-efficiency electric heating methods. In addition, the high-temperature water vapor humidified by the electrode humidifier condenses first when it encounters cold air, which raises the temperature of the purified air and requires the cooling water coil of the air handling unit to cool it down. Items (2), (3) and (4) result in the high energy consumption of the system throughout the year.

[0004] The renovation plan for completely dismantling and rebuilding such old cleanroom air handling units faces three major engineering challenges: high investment costs (including equipment investment, civil engineering coordination, and cleanliness re-inspection), long downtime (critical clean areas such as hospital operating rooms and ICUs cannot accept long-term shutdowns), and high cleanliness risks (demolition construction can easily damage the existing enclosure structure and airflow organization, and the re-inspection and re-operation cycle is long). Therefore, while retaining the original main structure of the old air handling unit and the original emergency redundant components (original electric heating module, original chilled water coil module, original electrode humidifier), an independent dehumidification module (dedicated to humidity control independent of the original main chilled water coil, embedded in the air handling unit using an embedded installation structure) and an independent humidification module (dedicated to preheating and isenthalpic humidification of fresh air in the purification area independent of the original electrode humidifier, externally installed with one hole on the upstream side wall of the fresh air duct valve of the purification air conditioning subsystem, connected via a flexible duct + round-to-square connector, the module has its own centrifugal fan for active pressurization and air supply, the original fresh air return path is not interrupted, dual sources are connected in parallel, and a matching blind plate allows for seasonal switching, the same below) is added—one embedded The in-line and external heat exchange modules form a spatial symmetry, clearly defining them as two independent heat exchange modules in terms of physical layout, providing a prerequisite for physical interlocking of the interlocking relays in the electrical control circuit. A new independent decoupling circuit (including circulating water pipes, circulating water pumps, mode-switching three-way valves, and external interfaces) is added to connect the independent dehumidification module, the independent humidification module, and the independent air supply duct of the purification area, undertaking the energy cascade utilization of condensation heat reheat, waste heat recovery humidification, and external heat source access. An interlocking intermediate relay is added to the electrical control circuit to physically interlock the start signals of the independent dehumidification module and the independent humidification module—forming a progressive modification scheme of "new module undertaking base load + original equipment undertaking peak shaving and emergency response." The modification boundary of this invention is strictly limited to the purification air handling unit itself and its external interfaces (according to the engineering convention of building electrical modification design—only drawing the scope of this modification and not drawing along the incoming cable to the power room). The water pipe routing outside the air handling unit and the details of the external heat / cold source host parameters are not within the scope of this specification; only the functional description of the external interfaces is used to depict their connection relationship. The above-mentioned renovation plan has become a realistic and feasible path for upgrading and replacing this type of old air conditioning purification system.

[0005] In the aforementioned renovation scenarios, the existing technologies still have the following problems regarding the control level of the original operation mode of the aforementioned old clean air handling units and similar existing renovation solutions.

[0006] Question 1: Dehumidification in clean areas during summer relies on low-temperature chilled water, resulting in extremely low energy efficiency. To meet the dehumidification needs of clean areas, traditional solutions supply 5-7℃ low-temperature chilled water to the clean air handling units. If the clean area and non-clean area share the same central air conditioning chilled water, the low-temperature chilled water will cause excessive condensation and dehumidification in the non-clean area, wasting cooling capacity; simultaneously, the low-temperature water supply leads to a significant decrease in the chiller's energy efficiency ratio. If the clean area uses independent air-cooled modules for cooling, the energy efficiency ratio of the air-cooled system is lower than that of the water-cooled system, and the added energy consumption from corresponding water pumps, etc., still results in a relatively high overall energy consumption for the cooling source system and a reduced overall reliability of the cooling source.

[0007] Question 2: High energy consumption of electric heating in cleanrooms during summer. Cleanrooms require constant temperature and humidity. In summer, dehumidification requires cooling and condensing the air before reheating. While traditional electric heating for air reheating is fast, it has high power consumption and low energy efficiency, necessitating careful consideration of the recovery and utilization of waste heat from air condensation. Summer often sees brief periods of extreme high temperature and humidity. Traditional control systems cannot precisely adjust the fresh air volume to reduce electric heating energy consumption; it's common to see situations where outdoor temperatures are high, yet the air handling unit's electric heating is operating at full power.

[0008] Problem 3: Severe internal heat loss in the cleanroom during winter. In winter, the cleanroom uses electrode humidifiers. When 100℃ steam encounters cold air, it first condenses and heats the air, causing it to overheat. This overheating necessitates cooling, which in turn causes further condensation and dehumidification. Simultaneously, the cooling coil continuously supplies cooling, and electric heating compensates for the temperature rise—cooling, electric heating, and electrode humidification operate concurrently, resulting in unnecessary mutual cancellation of cooling and heating, leading to extremely low system efficiency. There is a natural delay in return air temperature and humidity measurement, causing repeated oscillations and switching between humidification and dehumidification. It is common to see significantly cold weather outdoors, yet the chilled air handling unit still needs to continuously cool the cleanroom air handling unit.

[0009] Question 4: Inherent Defects of Traditional Series-Based Humidity Control. Traditional cleanroom air conditioning temperature and humidity control schemes execute the temperature control loop and the relative humidity control loop in series and alternately. During temperature control, if the relative humidity deviates significantly, and during humidity control, if the temperature deviates significantly, upper and lower thresholds are set for each process to prevent excessive deviation. Once either temperature or humidity control fails to meet the target, the system gets stuck in that process and continues to adjust, while the other target continues to deviate significantly from the set value. Throughout the year, this results in alternating deviations: "humidity deviates during temperature control, and temperature deviates during humidity control," making it difficult to simultaneously stabilize the air supply parameters in the cleanroom. Furthermore, since relative humidity is used instead of absolute humidity (dew point) as the humidity criterion, relative humidity itself is affected by temperature. When the temperature control process disturbs the indoor temperature, the displayed relative humidity value also fluctuates, further exacerbating the alternating deviations. This dual coupling of "series-based alternating execution + relative humidity criterion" is the deep-seated root cause of the low overall energy efficiency of traditional temperature and humidity control schemes throughout the year. From the control topology level, this provides a clear comparative space for the "parallel regulation of two independent control lines without alternation" methodology described in this invention.

[0010] Question 5: The inherent limitations of existing automatic seasonal mode switching routes based on enthalpy-humidity charts. In recent years, methods have emerged that use enthalpy-humidity chart zoning to automatically switch cleanroom fresh air conditioning systems between winter / summer / spring / autumn modes (a typical example is CN202511767732 "Automatic Control Method for Seasonal Mode of Cleanroom Fresh Air Conditioning Based on Enthalpy-Humidity Chart", 2026-05-06). (Publicly disclosed) This type of method uses the location of outdoor temperature and humidity in the enthalpy-humidity chart as the trigger for seasonal modes, which has the following shortcomings: (a) When using enthalpy or temperature-humidity composite parameters as criteria, the same enthalpy value can correspond to multiple different combinations of (temperature, relative humidity). In process scenarios such as orthopedic surgery, where enthalpy values ​​change within a short period of time, with significant temperature changes and relatively stable humidity, the purification control system's judgment on "whether to dehumidify or humidify" may have multiple solutions or boundary oscillations, and still cannot eliminate the contradictory state of switching between humidification and dehumidification from the source; (b) The "three-season mode switching" of this type of method has an intermediate transition state in the spring and autumn transition seasons. In the transition state, humidification and dehumidification are not strictly physically interlocked at the control logic level. The above limitations make the enthalpy-humidity chart zoning route have obvious shortcomings in terms of energy-saving potential, control stability, and engineering replicability.

[0011] Question 6: The surrounding high-power heat and cold sources and the cleanroom air conditioning system are physically independent and lack a joint supply integration interface. Inside large public buildings such as hospitals and industrial complexes, in addition to the cleanroom air conditioning system itself, there are multiple high-power heat and cold sources that exist simultaneously for a long time: the refrigeration room (including centrifugal chillers, screw chillers, and air-cooled modular units) continuously emits condensation heat into the atmosphere during the cooling season, and the air-cooled heat pump of the centralized hot water system emits evaporation cold into the atmosphere at the same time; In winter, the centralized hot water system emits evaporative cooling into the atmosphere during heating operation, while surrounding machine rooms and warehouses still require cooling. These surrounding energy systems and the cleanroom air conditioning system are physically independent—condensation heat is discharged into the atmosphere by cooling towers, process cooling loads are supplied by independent cold sources, and waste heat and waste cooling are discharged into the environment independently, resulting in large-scale energy waste. Even though the total heating and cooling volume of the surrounding energy systems does not perfectly match the cleanroom air conditioning demand at its peak throughout the year (condensation heat from refrigeration machine rooms is seasonal, and cold source usage is time-dependent), there is still significant room for integration during periods of overlapping base loads (such as the asynchronous condensation heat during winter weekdays and the non-synchronous preheating of fresh air by the cleanroom air conditioning, or the synchronous reheating of waste water from the power room during summer weekdays and the summer reheating by the cleanroom air conditioning). In existing technologies, the water circuits of old cleanroom air handling units (including the original state of the aforementioned old air handling units and existing similar renovation schemes) are all closed single chilled water mains, lacking external interfaces for recovering and utilizing non-cold waste heat. Physically, it is impossible to connect waste heat from surrounding high-power heat sources for winter fresh air preheating and humidification, nor can it connect waste cold from surrounding cold sources for summer supplemental cooling. At the same time, existing control strategies also lack time-scheduling logic, failing to achieve a non-perfectly matched joint supply mode where "the surrounding cold and heat sources and the cleanroom air conditioning demand overlap during peak hours, while non-overlapping hours are maintained by internal circulation within the unit." The dual lack of physical interfaces and time-scheduling logic has long shelved the integration potential of surrounding long-term high-power cold and heat sources, making it difficult to translate into a considerable energy-saving contribution to the cleanroom air conditioning system. Summary of the Invention

[0012] I. Technical problems to be solved 1. How to establish a unified seasonally differentiated control framework to achieve mutually exclusive operation and smooth switching between summer dehumidification and winter humidification in the purified area; 2. How to increase the chilled water supply temperature of the central air conditioning unit and improve the chiller's energy efficiency ratio while meeting the dehumidification requirements of the clean area; 3. How to eliminate the heat loss caused by the simultaneous operation of cooling and electric heating in the clean area during winter; 4. How to configure independent control loops for dehumidification and humidification functions within the air conditioning and purification subsystem, so as to achieve physical independence of the two modules at the hardware level and decoupling of their control logic level; 5. How to utilize the cooling and heating energy of the dehumidification process, as well as waste heat recovery, to drive humidification and achieve cascaded utilization of system energy; 6. How to replace enthalpy or temperature and humidity composite parameters with a single variable at the control criterion level to avoid multiple solutions and boundary oscillations in seasonal model judgments; 7. How to construct a physical interlock between humidification and dehumidification at the control logic level to prevent the transition state of their parallel operation from the source; 8. How to establish a time-limited, non-perfectly matched physical connection point between the existing air conditioning system and surrounding long-term high-power heat and cold sources (refrigeration room condensation heat, steam condensate waste heat, data center heat dissipation, process cooling load, etc.) to integrate the waste heat and waste cooling of surrounding energy systems into the energy cascade utilization loop of the cleanroom air conditioning system during the base load overlap period, so as to achieve synergistic energy saving between surrounding energy assets and cleanroom air conditioning needs.

[0013] II. Technical Solution This invention proposes a seasonally differentiated energy-saving control method and system for air-conditioning purification based on dew point temperature. The core innovation lies in using outdoor air dew point temperature as the sole criterion to construct a three-in-one, inseparable technical solution combination of "dual-module independent differentiation + seasonal differentiation + strict mutual exclusion." These three core anchor points—criteria anchor point, spatial anchor point (independently set control loops for the independent dehumidification module and independent humidification module within the purification subsystem), and execution anchor point—are essential technical features that cannot be separated and are implemented together. The absence of any one of them would prevent the complete technical solution of this invention from being achieved.

[0014] Criterion Anchor Point – Using outdoor dew point temperature as the sole criterion: The dew point temperature of air is an essential parameter reflecting the moisture content of air. At the same dew point temperature, the moisture content of the air remains constant regardless of temperature changes. This invention uses the outdoor air dew point temperature as the sole criterion for seasonal condition switching and overall humidity control direction determination. It does not introduce enthalpy, temperature-humidity composite parameters, or other seasonal model judgment parameters, nor does it introduce pre-defined spring / summer / autumn / winter season labels or date labels as input for condition switching. This single-variable decision avoids the "multiple solutions—boundary oscillations—mode conflicts" problem caused by multiple combinations of (temperature, humidity) corresponding to the same enthalpy value under the enthalpy criterion, and also eliminates the problem of control logic confusion caused by temperature changes when relative humidity is used as the control target.

[0015] Criterion Anchor Point Essential Argumentation—Preventing Over-Operation in Both Summer and Winter: Using dew point temperature as the sole criterion is not equivalent to "single-point control of a single parameter." Its essence is a two-way defense anchor point for "preventing over-humidification" in both summer and winter—preventing excessive dehumidification in summer and excessive humidification in winter—while enthalpy or composite temperature and humidity parameters cannot simultaneously fulfill the function of "over-humidification defense" in both directions with a single variable. Specifically: (I) "Over-dehumidification" defense line under the overall dehumidification operation in summer: The output of the independent dehumidification module is controlled by the indoor dew point temperature of the clean area as the only main control parameter. The dew point target is set at 10-14℃ neutral line (to meet the process requirements of 40-60% relative humidity in the clean area and keep the humidity within the safe bandwidth of allowable fluctuations). When the dew point has fallen into the 10-14℃ neutral line, the independent dehumidification module is scheduled according to "maintain current level" or "downgrade operation" to eliminate secondary problems such as secondary cooling waste, secondary reheat compensation energy consumption and physical discomfort caused by excessive air dryness caused by excessive dehumidification from the source. At the same time, the chilled water supply temperature of the central air conditioning unit is moderately raised according to the range defined in the claims. The chiller is freed from the dehumidification task and focuses on temperature control, and the energy efficiency ratio is significantly improved, forming an active anti-over-dehumidification defense line on the air supply side of the clean area in summer.

[0016] (II) "Over-humidification" defense line under overall humidification conditions in winter: The output of the independent humidification module is controlled by the indoor dew point temperature of the purified area as the sole main control parameter. The dew point target also uses the 10-14℃ neutral line as the safe fluctuation bandwidth. When the dew point has fallen into the 10-14℃ neutral line, the independent humidification module is scheduled to "maintain the current level" or "degrade operation" to prevent over-humidification. Because once over-humidification occurs, the old system must start the dehumidification module in reverse to remove excess moisture, thus forming a reverse internal friction cycle of "humidification → over-humidification → reverse dehumidification → reverse over-humidification → re-humidification". This reverse internal friction is one of the core causes of high energy consumption in traditional temperature and humidity composite control schemes in winter. The dew point neutral line (10-14℃) mechanism ensures that the humidity is allowed to fluctuate naturally within this safe range without triggering reverse operation - forming a complete echo with steps S4, 9, and 21 of weight 1, and jointly eliminating reverse internal friction from the source from the three layers of control criteria, control logic, and hardware execution.

[0017] (III) The Irreplaceability of the Two-Way Defense Line: When enthalpy is used as a criterion, the same enthalpy value can correspond to multiple combinations (temperature, humidity). When the control system judges whether "excessive dehumidification" or "excessive humidification" has occurred, multiple solutions will appear. It is impossible to simultaneously define the two defense lines of "preventing excessive dehumidification in summer" and "preventing excessive humidification in winter" on a single variable. The composite parameter criterion of temperature and humidity causes the "excess" judgment boundary to drift with temperature due to the coupling of the two parameters (temperature change leads to relative humidity change), and it also cannot serve as the anchor point of the two-way defense line. As the essential physical quantity reflecting the absolute water content of the air, dew point temperature can serve as the "preventing excessive" judgment with the same physical quantity, the same neutral bandwidth (10-14℃), and the same comparison relationship in both summer and winter. It is the only physically feasible choice for the anchor point of the two-way defense line. Therefore, "using dew point as the sole criterion" is not an engineering experience preference, but the only feasible physical criterion for the core control objective of "preventing excessive operation in both summer and winter". This is in complete correspondence with the "dew point temperature as the sole input parameter, without introducing enthalpy, without introducing a composite criterion of temperature and humidity, and without introducing seasonal labels" as defined in weight 19.

[0018] (iv) A two-layer dew point comparison architecture in which humidity control lines and temperature control lines are connected in parallel and independent, and do not alternate: The temperature and humidity decoupled differential control strategy of the present invention is further developed into a complete control philosophy at the methodological level: "two-layer dew point comparison + two-line parallel independent + asymmetric bandwidth + short-time over-limit exemption", which is fundamentally different from the traditional temperature and humidity series alternating control (see Background Technical Issue 4 for details).

[0019] ① Two-layer dew point comparison architecture: The dew point comparison of this invention is divided into two layers: static external comparison and dynamic internal comparison; The static external comparison compares the actual outdoor dew point temperature with the set dew point temperature of the clean area to determine the overall humidification or dehumidification condition of the current season. Based on this, the macro-level input and output of the humidification or dehumidification module is determined. Since the set temperature / dew point of the clean area is basically stable and the outdoor temperature / dew point is relatively stable in the direction of the indoor set value within the same season, this judgment is basically stable within the same season and belongs to the static judgment layer. The dynamic internal comparison compares the actual dew point temperature in the clean area with the set dew point temperature in the clean area to determine the start-up, shutdown and level adjustment of the modules that have been put into operation in real time. This judgment is performed in real time at the second / minute level and belongs to the dynamic judgment layer. The two layers are independent of each other and perform control functions at different time scales, together forming the complete criterion system for the humidity control line of this invention.

[0020] ②·The humidity control line and temperature control line are connected in parallel and independent, without alternation: The humidity control line and temperature control line of this invention are independently and parallelly regulated within the air-conditioning subsystem. Except for sharing the same operating condition judgment result (step S2), the control loops are completely physically independent and their execution logic is completely parallel. Neither line alternates until the other line reaches its target—the humidity line converges independently based solely on the dew point, and the temperature line converges independently based on external cooling / heating. The two lines advance synchronously in time and do not interfere with each other spatially. When the actual indoor dew point and actual indoor temperature reach their respective set values, the corresponding relative humidity naturally meets the process requirements. This parallel independent structure fundamentally eliminates the alternating deviation defect of traditional series-rotation schemes, where "humidity is biased when controlling temperature, and temperature is biased when controlling humidity," at the topological level. This is the core control philosophy that distinguishes this invention from traditional temperature and humidity control schemes.

[0021] ③ Humidity control line uses dew point as the sole criterion and does not consider temperature in decision-making: The adjustment logic of the humidity control line is simplified to "humidify when the air moisture content is insufficient and dehumidify when the air moisture content is excessive" - ​​the criterion is absolute humidity (dew point) rather than relative humidity, and the decision does not consider temperature conditions; this simplification allows the humidity control line to completely get rid of the disturbance of relative humidity criterion by temperature changes, and the humidity line itself can stably converge to the indoor set dew point, providing physical feasibility for the two lines to be connected in parallel and independently.

[0022] ④ The true purpose of distinguishing between overall operating conditions: The fundamental purpose of distinguishing between overall humidification and overall dehumidification operating conditions is not to prevent temperature disturbances, but to prevent repeated alternation between humidification and dehumidification in a short period of time. Humidification and dehumidification are two independent modules at the hardware level, with opposite execution directions. If the two modules are allowed to alternate according to humidity requirements at any time, there will be repeated switching between humidification and dehumidification at the second or minute level, forming a reverse internal friction cycle of "humidification → over-humidification → reverse dehumidification → re-humidification". This invention introduces a stabilizing layer of overall operating conditions, stabilizing the time scale of module input / output at the seasonal scale (determined by static external comparison) and limiting the time scale of module-level adjustment to the second level (determined by dynamic internal comparison). The two time scales are decoupled, fundamentally eliminating the reverse alternation at the module level.

[0023] ⑤ Temperature control line can be adjusted independently in real time as needed: The temperature control line can be adjusted independently in real time by the chilled water of the central air conditioning unit (under overall dehumidification) or the independent air-cooled heat pump unit (under overall humidification); the adjustment of the temperature line is not constrained by the humidity line and does not wait for the humidity line to reach the standard; since the humidification module adopts isenthalpic humidification (without introducing sensible heat) and the condensation waste heat of the dehumidification module is used for reheating through an independent decoupling closed loop (without leakage to disturb the indoor temperature), the disturbance of the humidity line to the temperature line is reduced to a negligible level in engineering, and the temperature line can independently and stably converge to the indoor set temperature.

[0024] ⑥ • Asymmetric bandwidth • Short-term out-of-bounds exemption • Dual-dimensional division of labor between dew point and relative humidity • Examples are not limited: (a) Dual-dimensional division of labor between dew point and relative humidity: The start-up signals for module activation and deactivation are strictly determined by the dynamic internal comparison between the indoor dew point temperature (absolute humidity index) and the set dew point temperature in the cleanroom. The dew point criterion is unaffected by temperature changes and constitutes the sole physical criterion for module activation and deactivation within the control system of this invention. Relative humidity serves as a display parameter that maintenance personnel can visually read at the cleanroom terminal and as a humidity index corresponding to human perception. It is used for project acceptance comparison, terminal observation, and operational status feedback. However, relative humidity is not used as a direct trigger for module activation and deactivation (to avoid control logic confusion caused by relative humidity being affected by temperature changes). Dew point = physical criterion (internal), relative humidity = visual display at the terminal (external), the two constituting a dual-dimensional index system of "internal and external division of labor".

[0025] (b) Asymmetric Bandwidth - Engineering Examples: At the specific engineering numerical level (taking the Foshan area hospital cleanroom RH 50-60%, median 55% as an example, other projects flexibly select the corresponding sub-range according to local or industry cleanroom regulations), under the overall dehumidification condition, the humidity setpoint is set towards the upper limit of RH (e.g., 57%), allowing RH to fluctuate within ±3% bandwidth between 54-60%, and allowing short periods below 54% but not below 50% (temporary shutdown without humidification due to excessive dehumidification); under the overall humidification condition, the humidity setpoint is set towards the lower limit of RH (e.g., 53%), allowing RH to fluctuate within ±3% bandwidth between 50-56%, and allowing short periods above 56% but not above 60% (temporary shutdown without dehumidification due to excessive humidification). The humidity setpoints for the two operating conditions are asymmetrically distributed within the total RH range of the cleanroom area—the humidification state is slightly lower than the limit, the dehumidification state is slightly higher than the limit, and the median value of 55% serves as the boundary reference between the two operating conditions—each has a ±3% allowable fluctuation bandwidth and a buffer zone is reserved between the upper and lower limits of the cleanroom RH.

[0026] (c) Avoiding Natural Return Air Delay and Over-Adjustment: The return air temperature and humidity measurement in the air-conditioning subsystem has a natural delay, and there is a structural time lag between module action and terminal sensor response. If bandwidth protection is not implemented and a target setting of "accuracy to a specific numerical point" is pursued, it will result in repeated module start-stop cycles, over-adjustment, and energy waste due to excessive dehumidification / humidification. The ±3% fluctuation bandwidth described in this invention is precisely to absorb the overshoot caused by this natural return air delay—the overshoot caused by the delay is absorbed within the ±3% bandwidth, and further overshoot is absorbed within the buffer zone between the bandwidth and the upper and lower limits of the clean zone RH due to the mutual exclusion of overall dehumidification and overall humidification. Even if the system structural time lag is large, it is actually difficult to exceed the upper and lower limits of the clean zone RH and trigger reverse operation, while avoiding the energy waste caused by excessive adjustment in pursuit of high precision from the source.

[0027] (d) Example and non-limiting statement: The specific values ​​mentioned in this paragraph (53%, 57%, ±3% fluctuation bandwidth, 55% median value, 10-14℃ dew point neutral line, 5% buffer, etc.) are all example data. The present invention protects the control logic method itself of "dew point physical criterion-driven + relative humidity terminal display + asymmetric bandwidth + ±3% fluctuation + short-term over-limit exemption + reverse operation prohibition". The specific values ​​can be flexibly selected according to the process requirements of different clean areas and do not constitute a limitation on the scope of protection of the present invention.

[0028] The above six methodologies, together with the three inseparable control anchors (unique dew point criterion / independent differentiation of dual modules / strict mutual exclusion physical interlocking), constitute the complete control philosophy of this invention. The absence of any one link will prevent the achievement of the overall technical effect of "stable air supply parameters in the purification zone + dual compliance of temperature and humidity + significant improvement in comprehensive energy efficiency throughout the year".

[0029] Spatial Anchor Point – Independent control loops for the independent dehumidification and humidification modules within the air conditioning and purification subsystem, along with decoupled and differentiated temperature and humidity control: Based on the different requirements of hardware actuators for summer dehumidification and winter humidification, independent control loops are configured for independent dehumidification modules and independent humidification modules, and a differentiated control strategy of temperature and humidity decoupling and division of labor is implemented.

[0030] • Independent dehumidification module control loop: Equipped with dedicated start / stop signals, temperature and humidity sensors, pure refrigerant refrigeration loop, condenser side reheat interface, and excess heat transfer proportional integral valve, etc.; Under overall dehumidification conditions, it undertakes the humidity control load of the purified area, while the chilled water of the central air conditioning unit mainly undertakes the temperature control load, realizing the decoupling of temperature control and humidity control; Under overall humidification conditions, it is forcibly locked to the off state by the operating condition interlock. • Independent humidification module control loop: Equipped with dedicated start / stop signals, circulating water pump / proportional integral valve, waste heat recovery heat source interface, and fresh air preheating interface; Under overall humidification conditions, it undertakes the humidity control load of the purified area, the fresh air preheating section undertakes the primary heating load (mandatory), and the independent dehumidification module connects to an external heat source via an external interface to undertake the secondary heating load (optional); Under overall dehumidification conditions, it is forcibly locked into a disabled state by the operating condition interlock. • The control loops of the two modules are physically independent at the hardware level and operate completely independently at the control logic level, except for sharing the same operating condition judgment result; they are uncoupled and do not affect each other; they only share mutual exclusion signals on the interlocking relays.

[0031] Seasonal differences: Based on the comparison between the outdoor air dew point temperature and the set dew point temperature inside the clean area, determine the current overall humidity control direction: • Overall dehumidification mode (summer): Outdoor dew point is higher than indoor set dew point, dehumidification is required. • Overall humidification mode (winter): Outdoor dew point is lower than indoor set dew point, humidification is required. • There is no transition between the two operating conditions; dehumidification and humidification will never be performed simultaneously.

[0032] Execution anchor point – the strictly mutually exclusive physical interlocking operation of the independent dehumidification module and the independent humidification module: The independent dehumidification module and the independent humidification module operate strictly mutually exclusively, forming a physical interlock at the control logic level—only one of them is allowed to be in the start state at any given time, and simultaneous operation is prohibited, nor is a transitional operation mode for parallel operation set. The physical interlock can be implemented in one or more combinations of the following ways: (a) Boolean mutual exclusion logic (XOR or interlocked relay); (b) electrical hard interlock using a shared switching switch or interlocked intermediate relay; (c) a three-state machine of "dehumidification operation—both stopped—humidification operation"; the switching of operating conditions strictly follows the sequence of "first stop the current module—confirm the humidity drop to a safe range—then enable the reverse module," and during the switching process, there is at least a transitional shutdown period where both are stopped, and there is absolutely no transitional operation period where both operate in parallel. This fundamentally eliminates the problem of repeated oscillation switching between humidification and dehumidification in traditional solutions, and distinguishes it from the potential risk of parallel operation of both modules in the spring and autumn transitional states of enthalpy-humidity chart zoning routes.

[0033] Specific measures for overall dehumidification in summer: 1. Activate the independent dehumidification module to handle the dehumidification load of the clean area. 2. The chilled water supply temperature of the central air conditioning unit is moderately increased within the range specified in the claims, freeing the chiller from dehumidification tasks and significantly improving its energy efficiency ratio. 3. The refrigerant condensation heat from the independent dehumidification module is used for reheating to replace electric heating. 4. The refrigerant evaporation cooling capacity of the independent dehumidification module is used for deep condensation dehumidification of the purified air. 5. Independent dehumidification module: If the air reheat four-way hot water coil is connected to an external proportional integral valve, excess heat can be transferred for external heating or dissipation, thereby protecting the compressor and regulating the amount of air reheat heat. 6. Discontinue the use of inefficient and energy-intensive standby air-cooled modules and replace them with a water-cooled central air conditioning system for cooling. 7. Two-stage cooling system: The first stage uses the existing chilled water coils of the purification air handling unit to pre-cool the mixed fresh and return air from its initial state to 14~18℃ / RH≥90% (primarily sensible heat cooling, supplemented by condensation dehumidification, effectively serving as peak-shaving dehumidification in hot and humid weather); the second stage uses an independent dehumidification module to deeply condense and dehumidify the pre-cooled portion of the purified air to saturation; finally, the independent dehumidification module reheats the air to the supply air state via a self-circulation reheat path or a refrigerant + water solution. 8. Self-generated reheat instead of electric reheat: The condensation heat of the independent dehumidification module's refrigeration cycle is transferred to the hot water coil via a self-circulating reheat path or a refrigerant + water solution path, performing isohumidity reheat on the deeply dehumidified air. No external electric heating or additional heat source supply is required, forming a "compressed dehumidification loop with self-generated reheat". 9. Retention and downgrading of original components: The original chilled water coil is retained for main cooling in summer and peak cooling under extreme conditions; the original electric heating module is retained as an emergency heating component in case of dehumidification module failure.

[0034] Specific measures for overall humidification operation in winter: 10. Activate the independent humidification module to preheat and isenthalpically humidify the fresh air in the purified area. 11. The heating source is hot water (produced by independent air-cooled heat pump units corresponding to each purification area) or waste heat (waste heat recovered and utilized from the surrounding machine rooms in winter, including waste heat generated from cooling). 12. During winter shutdown and maintenance of the central air conditioning unit, the cooling source for the cleanroom will be replaced by an independent air-cooled heat pump unit (independent of the central air conditioning unit) for each cleanroom, eliminating internal cooling and heating losses. 13. Replacing electric heating with hot water coil heating or refrigerant condensing coil heating increases the energy efficiency ratio from 1.0 to over 3.0 (if waste heat generated from cooling in the surrounding computer rooms of the cleanroom is recovered and utilized, the overall energy efficiency ratio of the combined cooling and heating system will be even higher). 14. Reduce or eliminate the use of electrode humidifiers to avoid a vicious cycle of overheating and cooling caused by steam humidification. 15. Isoenthalpic humidification does not inject additional heat into the air, and heating and humidification do not interfere with each other. 16. Tiered heating base load: The independent humidification module's fresh air preheating section serves as the primary heating stage (main, mandatory), while the independent dehumidification module's hot water coil provides secondary heating (auxiliary, optional) when connected to an external heat source; the two stages operate synchronously in series along the airflow direction, jointly covering the basic heating needs of the air-conditioning system in winter, avoiding reliance on electric heating or high-power operation of a single hot water coil for reheating in winter. 17. Retention of original components and emergency use: The original electric heating module, after being configured with reduced power, will be retained as a rapid peak-shaving heating component (to supplement heat when the outdoor temperature drops suddenly or the base load of the two-stage heating is insufficient); the original electrode humidifier will be retained as an emergency humidification component when the independent humidification module fails and stops, and will not be used as a normal humidification method.

[0035] III. Beneficial Effects Effect 1: Establishing a unified framework for controlling seasonal differences

[0036] This invention proposes for the first time a three-dimensional control framework based on dew point temperature as a unified criterion, which integrates the independent desiccation module and the independent humidification module control loops within the purification subsystem into a unified technical solution. This framework decouples the independent desiccation module and the independent humidification module control loops (spatial dimension), differentiates the desiccation strategies for summer and humidification for winter (time dimension), and integrates the mutually exclusive operation logic of desiccation and humidification (execution dimension).

[0037] Effect 2: Significantly improved energy efficiency ratio of the chiller Under summer operating conditions, after the independent dehumidification module undertakes the dehumidification task of the clean area, the chilled water supply temperature of the central air conditioning unit is moderately increased within the range defined in the claims, resulting in a significant improvement in the chiller's COP / IPLV. The required cooling capacity or number of units required under the same operating conditions is reduced; for example, previously two 1000-ton centrifugal chillers needed to be operated, now only one 1000-ton centrifugal chiller and one 300-ton screw chiller are required at most. The overall energy consumption of the chillers and their pumps is significantly reduced, thereby significantly improving the system's energy efficiency ratio.

[0038] Effect 3: Eliminates internal friction between hot and cold. In winter, the central air conditioning unit does not participate in cooling the clean area; instead, the cooling source for the clean area is switched to the independent air-cooled heat pump units (independent of the central air conditioning unit) corresponding to each clean area, completely eliminating the internal heat loss caused by simultaneous operation of "cooling + electric heating"; isenthalpic humidification does not inject additional heat into the air, avoiding the vicious cycle of overheating and cooling caused by traditional electrode humidification. Internal heat loss is drastically reduced, and system energy efficiency is significantly improved.

[0039] Effect 4: Energy cascade utilization Summer: The condensation heat of the independent dehumidification module is used for reheating (replacing electric heating, increasing the energy efficiency ratio from 1.0 to over 3.0), and the cooling capacity is used for pre-cooling chilled water return (reducing the load on the main unit). Winter: Use hot water or waste heat recovery to heat fresh air (replacing electric heating, increasing the energy efficiency ratio from 1.0 to over 3.0; if it is a system that recovers and utilizes waste heat from the winter cooling area to achieve combined cooling and heating, the energy efficiency ratio will be even higher).

[0040] Effect 5: Stable air supply quality in the purification zone After the control loops of the independent dehumidification module and the independent humidification module are completely physically independent: under dehumidification mode, the dew point of the supply air in the purification zone is stably controlled within the neutral line of 10-14℃; the condensation dehumidification process and the reheating process are clearly separated and do not interfere with each other; under humidification mode, the fresh air preheating and isenthalpic humidification in the purification zone are tiered and regulated; temperature and humidity are regulated independently and are not coupled; the humidification process does not introduce 100℃ steam (there is no additional sensible heat, thus reducing the cooling condensate inside the purification air handling unit); the modification and maintenance have little or no impact on the purification air handling unit, and the quality of the purified air is stable.

[0041] Effect 6: Improved humidity control stability The mutually exclusive operation strategy fundamentally eliminates the problem of repeated oscillations and switching between humidification and dehumidification. The dew point temperature fluctuation in the clean area is controlled within ±1℃, and the temperature and humidity are simultaneously stabilized after decoupling control.

[0042] Effect 7: The air conditioning system has significant overall energy-saving effect. Key contribution: The annual electricity consumption of the air conditioning system has decreased from approximately 3.09 million kWh (peak in 2019) to approximately 1.51 million kWh (trough in 2025), a reduction of more than 50%, resulting in a reduction of approximately 1.58 million kWh of electricity consumption per year. Note: The above data comes from engineering experiments, not rigorous scientific research control experiments; the statistical scope corresponds to approximately 4339㎡ of "fully clean area in use" (including 6 areas: operating room, ICU, second-stage neonatal, supply room, delivery room, and endoscopy center), excluding semi-clean areas and unused clean areas.

[0043] Effect 8: Gradual renovation retains the original equipment investment. After introducing independent dehumidification and humidification modules, the original electric heating module, chilled water coil module, and electrode humidifier of the purification air handling unit are not removed, but their roles are redefined: the electric heating module is configured with reduced power to serve as a rapid peak-shaving heating component or an emergency heating component in case of module failure, with a response speed superior to water circuit regulation; the chilled water coil is retained as the main cooling component in summer, and works in conjunction with the refrigerant evaporation coil of the dehumidification module to condense and dehumidify the air; the electrode humidifier is retained as an emergency humidification component in winter. This gradual transformation approach, where "new modules handle the base load + original equipment handles peak shaving and emergency response," preserves the original equipment investment to the greatest extent, avoids a one-size-fits-all removal and replacement, and allows the energy-saving transformation of the old purification air conditioning system to proceed step by step without affecting the original emergency redundancy.

[0044] IV. Fundamental differences from the closest prior art (CN202511767732) The most recent prior art, CN202511767732, "Automatic Control Method for Seasonal Mode of Cleanroom Fresh Air Conditioning Based on Enthalpy-Humidity Chart" (published on 2026-05-06), discloses a method for automatically switching between winter / summer / spring / autumn modes of cleanroom fresh air conditioning using an enthalpy-humidity chart partitioning approach. This invention differs substantially from this closest prior art in the following three fundamental features, which constitute an inseparable combination of technical features that distinguish this invention from the closest prior art.

[0045] Difference 1 (Criterion Dimension): Unique Criterion vs. Enthalpy Partition The closest existing technology uses the location of outdoor temperature and humidity on the enthalpy-humidity chart as the trigger for seasonal modes. Essentially, it relies on "enthalpy or temperature-humidity composite parameters" as the criterion, leading to multiple solutions and boundary oscillations caused by the same enthalpy corresponding to multiple (temperature, humidity) combinations. This invention uses outdoor air dew point temperature as the sole criterion for seasonal mode switching, without introducing enthalpy, temperature-humidity composite parameters, or other seasonal mode judgment parameters, nor does it introduce pre-defined seasonal or date labels. Seasonal mode switching is determined solely by a univariate comparison between "outdoor dew point vs. the dew point set in the purification zone," eliminating multiple solutions from the outset.

[0046] Difference 2 (Structural Dimension): Independent dual-module differentiation within the purification subsystem vs. integrated coil system in the whole unit The closest existing technology is aimed at cleanroom fresh air conditioning units and can only be used for new cleanroom construction projects or the renovation of old cleanroom air handling units. This invention clearly separates the dehumidification and humidification functions within the cleanroom air conditioning subsystem into two independent modules: an independent dehumidification module (embedded installation, handling summer dehumidification base load + self-generated reheat) + an independent humidification module (external installation, handling winter fresh air preheating + isenthalpic humidification base load) + an independent decoupling circuit (mode switching three-way valve for physical isolation) + an interlocking relay (electrical hard interlock). These four hardware components form an inseparable whole. The two modules are equipped with independent control circuits, circulating water circuits, airflow interfaces, and cold / heat source interfaces. Except for sharing the same operating condition judgment results, the control circuits of the two modules are physically independent at the hardware level and operate completely independently at the control logic level, without coupling. The fundamental source of energy-saving potential lies in this independent dual-module differentiation—temperature and humidity control are assigned to dedicated actuators in both operating conditions, achieving complete decoupling between the two. Simultaneously, it provides the physical basis for two energy-saving pathways: self-generated reheat replacing electric reheat in summer and waste heat-driven humidification in winter. The modular design allows for the selection of one or both modules based on site conditions and needs, minimizing disruption to existing cleanroom operations and ensuring cleanroom safety while minimizing energy consumption.

[0047] Difference 3 (Execution Dimension): Strict Physical Interlocking vs. Three-Season Transitional Mode with Potential Parallelism The closest approximation to existing technology, the "three-season mode switching (winter / summer / spring / autumn)", has an intermediate transitional state during the spring and autumn transition season. In this transitional state, humidification and dehumidification processes may run in parallel, without establishing a strict physical interlock at the control logic level. This invention establishes a strict physical interlock between independent dehumidification and independent humidification modules at the control logic level—achieved through one or more combinations of Boolean mutual exclusion logic, interlocking intermediate relays, or a three-state machine of "dehumidification operation—both stopped—humidification operation". Only one of the two systems is allowed to be running at any given time; parallel operation is prohibited. During the switching of operating conditions, there must be at least a transitional shutdown period during which both systems stop. This physically eliminates the possibility of parallel operation from the control logic level.

[0048] The above three distinctions—criteria anchor point, spatial anchor point, and execution anchor point—are an inseparable combination of technical features that constitute the substantial technical contribution of this invention that distinguishes it from the closest prior art. The absence of any one of them would not constitute the complete technical solution of this invention.

[0049] V. The Synergistic Relationship Between the Control Method / System of the Invention and the Modified Hardware Carrier Unified Statement: The control method (claim 1) and control system (claim 12) described in this invention can only be fully implemented on a modified, older cleanroom air handling unit hardware platform. This hardware platform consists of five core hardware components— The independent dehumidification module (embedded installation), the independent humidification module (external installation), the independent air supply duct for the purification zone, the independent decoupling circuit (including external interface and mode switching three-way valve), and the interlocking relay—these five hardware components work together to form the physical carrier of the three-in-one core control anchor point (criteria / space / execution) of this invention. The table below lists the one-to-one correspondence and inseparable collaborative relationship between the five hardware components and the core control anchor point of this invention.

[0050] Summary of core collaborative relationships: one Independent dehumidification module (embedded) S3 Cleanroom Temperature and Humidity Dual-Parameter Decoupling Control It is independent of the original chilled water coil and is dedicated to humidity control; without this module, temperature and humidity are always simultaneously changed by the same integrated coil, making the S3 dual-parameter decoupling physically impractical. two Independent humidification module (external type) Winter primary heating base charge + isenthalpic humidification + waste heat driven humidification Independent of the original electrode humidifier, this unit is dedicated to fresh air preheating and isenthalpic humidification, and features a waste heat recovery interface. Without this module, the electrode humidifier's 100°C steam would inevitably inject additional sensible heat, making isenthalpic humidification impossible. three Independent air duct in the clean area The S3 purification subsystem uses a shared physical execution channel to decouple the dehumidification and humidification functions within its internal dehumidification subsystem. The cleanroom air handling unit has three external interfaces: ① Fresh air duct (directly connected to the outside, introducing fresh outdoor air); ② Return air duct (cleanroom area → air handling unit, introducing return air from the cleanroom area); ③ Outlet air duct (air handling unit → cleanroom area, supplying clean air to the cleanroom area). The fresh air duct has a coarse filter at the front end, the cleanroom air handling unit has a pre-filter + medium-efficiency filter, and the outlet air duct has a high-efficiency filter at the end. This system is dedicated to the clean air circulation within the cleanroom area and serves as a shared physical execution channel for the independent dehumidification control module and the independent humidification control module, allowing for time-sharing mode switching. This ensures the physical feasibility of decoupling the dehumidification and humidification functions within the cleanroom subsystem. Four Independent decoupling circuit The condensation heat reheat, waste heat recovery humidification, and external power supply described in claims 13 / 14 / 15 / 16 / 18 The original old air handling unit had a single water circuit and no decoupling loop; after the renovation, an independent decoupling loop was added, making it physically feasible to achieve summer condensation heat reheat (including both pure refrigerant and refrigerant + water dual-track systems), winter hot water or waste heat driven humidification, and external power supply. five Interlocking relay S4 and the strict physical interlock described in claim 21 The software-level "mutual exclusion" code can be bypassed; the interlocking intermediate relays forcefully lock the two to prevent them from being powered on simultaneously at the hardware electrical circuit level, thus giving the S4 physical interlock a strong hardware constraint that cannot be bypassed.

[0051] The essence of the collaborative four-way expansion—independent decoupling loop external interface: a combined cooling and heating hub for long-term surrounding heat and cold sources. The external interface and combined cooling and heating supply of the independent decoupling loop described in claims 13, 14, 15, 16, 17, and 18 not only serve the reuse of condensation heat and waste heat-driven humidification within the unit (this aspect has been fully undertaken by the aforementioned Coordination 4), but its deeper essence is that the external interface constitutes a physical access point connecting this system with the energy systems surrounding the hospital / industrial complex, upgrading this system from an "independent energy-saving control system" to a "connected-supply node of the hospital / industrial complex energy system." This essence can be demonstrated from the following three dimensions, forming a complete echo with the aforementioned background technology "Problem Six".

[0052] (i) The "two-way access" capability of the external interface is the physical basis for the integration of surrounding high-power cold and heat sources: The three ports of the mode switching three-way valve are respectively connected to the water-side interface of the condensing heat exchange tank, the water-side interface of the hot water coil, and the interface for external hot water supply / interconnection to external heat sources. The hardware supports two combined supply modes at the same time - the "external hot water supply" mode is to supply excess condensation heat (typical temperature 38~45℃) generated by the operation of the independent dehumidification module to the surrounding domestic hot water, low-temperature hot water terminals or process heating circuits through the external interface in summer; the "interconnection to external heat sources" mode is to allow hot water generated by the surrounding energy system (such as condensation hot water in the refrigeration room, waste heat of steam condensate in the boiler room, waste heat of cooling water in the power room water-cooled air conditioner, domestic hot water return water, and waste hot water from the independent air-cooled heat pump units corresponding to each purification area) to flow back into the inlet of the hot water coil of the independent dehumidification module through the external interface, as an external heat source for the secondary heating base load of the purification area in winter, while the needs of the surrounding cooling areas are also met. This two-way access capability is the direct solution to the limitation mentioned in Question 6, which states that "the surrounding energy system and the air purification system are physically independent of each other, and their energy is emitted into the environment by each system, resulting in large-scale waste."

[0053] (II) "Time-bound, non-perfectly matched combined heat and cooling" is the core scheduling logic of the external interface: the total amount of heating and cooling, peak periods, and temperature levels of the surrounding energy systems are not perfectly matched with the needs of the cleanroom air conditioning system—the condensing heat of the chiller room and the winter heating demand of the cleanroom air conditioning are mismatched, the domestic hot water load is diurnal, and the process cooling load is shift-based; however, combined heat and cooling ≠ total matching. The engineering value of combined heat and cooling lies in the "integration of overlapping base load periods"—the condensing heat of the chiller room during summer workdays is synchronized with the summer reheat of the cleanroom air conditioning, and the waste heat of the cooling water in the power room during winter workdays is synchronized with the winter fresh air preheating, all of which can be directly combined heat and cooling during overlapping periods; during non-overlapping periods, the independent decoupling loop of the unit maintains self-circulation. The three-mode switching mechanism of the mode switching three-way valve, namely "self-circulation reheat (excess heat for external heating) / external chilled water supply / connection to external heat source", provides the physical realization of this "time-bound, non-perfectly matched combined heat and cooling", making it a schedulable engineering solution at the hardware level.

[0054] (III) The "connectable power supply node" is the essential feature that distinguishes this system from existing technologies: Existing technologies (including the enthalpy-humidity diagram zoning method in CN202511767732, the original state of old purification air handling units, and existing similar retrofit schemes) are all closed-loop air conditioning control systems—the water circuit is a single chilled water / hot water main, without independent decoupling loops, without mode switching three-way valves, and without external interfaces. The control layer also lacks time-scheduling logic for coordination with surrounding energy systems, and can only save energy within the unit's internal circulation. The system described in this invention, through the external interface of an independent decoupling loop and the mode switching three-way valve, physically upgrades from a closed-loop air conditioning control system to an open-loop connectable power supply node, enabling bidirectional co-supply with surrounding energy systems such as refrigeration rooms, boiler rooms, power rooms, domestic hot water systems, and process cold sources during periods of overlapping base loads. The physical structure upgrade of the "closed-loop → interconnected power supply node" is one of the essential differences between this system and the existing technology (including CN202511767732), and is explicitly reflected in claims 15, 16, and 18 through technical features such as "external heat source connection mode", "bidirectional interface for external hot water supply / interconnection to external heat source", and "three-mode switching of the mode switching three-way valve".

[0055] Declaration of indivisibility: The above five synergistic relationships constitute an inseparable overall synergistic relationship between the control method / control system described in this invention and the modified hardware carrier. Without any one of the five hardware structural features, the core control anchor points corresponding to the control method / system described in this invention cannot be physically implemented, nor can they produce all the technical effects described in this specification. Conversely, even if the above hardware structural features are present, without implementing the three core control anchor points described in this invention (i.e., the criterion / space / execution three anchor points declared in the "three-in-one inseparable overall technical feature combination" at the end of weight 1 / weight 12), the energy-saving potential of the modified hardware carrier cannot be fully released. Attached Figure Description

[0056] Figure 1 System overall schematic diagram Connection relationships between the central air conditioning unit, the independent dehumidification module and independent humidification module in the clean area, the external interface of the independent decoupling loop, and the control system. Figure 2 Dew Point Judgment and Seasonal Differentiation Control Flowchart The complete logic of outdoor dew point → overall operating condition assessment → spatial differentiation strategy → seasonal differentiation execution Figure 3 Summer overall dehumidification system schematic diagram Independent dehumidification module + chiller collaboration + two-stage cooling capacity division + self-generated reheat dual-track system (pure refrigerant solution, or refrigerant + water solution). Figure 4 Winter overall humidification system schematic diagram Independent humidification module + waste heat recovery + isenthalpic humidification + cooling-to-heating switching + elimination of internal cooling and heating losses Figure 5 Mutually exclusive operation and humidity safety fluctuation range diagram Dehumidification / humidification three-state machine mutual exclusion logic + dew point neutral bandwidth + graded adjustment + relative humidity terminal control + ±3% fluctuation bandwidth diagram Figure 6 Energy efficiency comparison diagram Comparison of annual energy consumption between traditional solutions and the proposed solution Figure 7 Water circuit diagram before purification system renovation Overall schematic diagram of the central air conditioning, air-cooled modules and clean air handling units, and the water circuit before the renovation of the non-clean area. Figure 8 Before the purification system was upgraded - air circuit diagram Overall diagram of the air circuit before the purification system renovation Figure 9 Overall Dehumidification Phase After Purification System Upgrade - Water Circuit Diagram Schematic diagram of water circuit changes during the overall dehumidification phase after the purification system upgrade Figure 10 Overall Dehumidification Phase After Purification System Upgrade - Air Circuit Diagram Schematic diagram of air circuit changes during the overall dehumidification phase after the purification system upgrade Figure 11 Overall Humidification Phase After Purification System Upgrade - Water Circuit Diagram Schematic diagram of water circuit changes during the overall humidification phase after the purification system upgrade Figure 12 Overall Humidification Phase of the Purification System After Modification - Air Circuit Diagram Schematic diagram of the changes in the air circuit during the overall humidification phase after the purification system modification Detailed Implementation

[0057] Hardware Carrier Description of Examples: The specific implementation methods described in this invention are all based on the hardware carrier of a modified old cleanroom air conditioning subsystem. The hardware carriers of Examples 1 to 4 below are derived from a preliminary modification case of an old cleanroom air conditioning unit put into operation in 2008 in the operating department of a tertiary hospital. The original state of the unit before the modification was: a single integrated heat exchange coil (dehumidification and cooling coupled, located in the cleanroom air handling unit), the original old cleanroom air handling unit was dedicated to supplying air to the cleanroom area (passing through coarse + primary + medium filtration stages and terminal high-efficiency filters, only serving the cleanroom area), a single chilled water main pipeline (without an independent decoupling circuit), and an independent electrical circuit for the electrode humidifier (without an interlocking mechanism with the chilled water coil dehumidification); in winter, the cooling load of the cleanroom area was undertaken by the independent air-cooled heat pump units corresponding to each cleanroom area (independent of the central air conditioning unit).

[0058] The unit was modified according to the five core hardware components described in this invention (see the unified description in the section on collaborative relationships). Key points of the modification: (1) The original main structure and components of the air handling unit remain almost unchanged, and the original cold water coil is freed from the condensation and dehumidification function. The newly added independent dehumidification module adopts an embedded installation structure and is embedded in the space between the original cold water coil and the original electric heater of the air handling unit. The newly added independent humidification module adopts an external installation structure and is arranged on an interface on the side before the air valve of the fresh air duct of the air handling unit. (2) The air supply duct of the purification area is kept independent in the purification air cabinet (the original filter section remains unchanged). The water routing outside the air cabinet is an extension of the building HVAC renovation and is not discussed in this manual. (3) Add an independent decoupling loop (circulating water pipeline, circulating water pump, mode switching three-way valve and external interface, three modes: self-circulating reheat / external hot water supply / connection to external heat source), connecting the condenser side of the independent dehumidification module, the built-in hot water coil, the heating coil before the wet curtain of the independent humidification module and the external waste heat recovery pipeline; (4) Add an interlocking intermediate relay to physically interlock the start signals of the independent dehumidification module and the independent humidification module; (5) The original electric heating module, the original cold water coil module, and the original electrode humidifier are retained and their roles are redefined (see claims 17 and 18).

[0059] Example 1: Overall Dehumidification Conditions in Summer Operating conditions: A tertiary hospital in southern China, with an outdoor temperature of 35℃, relative humidity of 80%, and outdoor dew point temperature of approximately 31.5℃ in summer; the indoor temperature of the clean area is set at 24℃, and the dew point temperature is set at 12℃. S1. Parameter Acquisition and Dew Point Calculation: Outdoor weather station collects T... out=35℃, RH out = 80%, T is obtained according to the Magnus formula. dp out≈31.5℃; Indoor sensor data collection T in=24.5℃, RHin=55%, according to the rapid estimation method T dp in≈T in- (100-RH in) / 5 to get T dp approximately 15.5℃; S2. Overall operating condition judgment (based solely on dew point): T dp out=31.5℃ > T dp set=12℃ → Overall dehumidification mode; S3. Differentiated control strategy execution (the control loops of the independent dehumidification module and the independent humidification module within the purification subsystem are set independently): Independent dehumidification module control loop (active state): The independent dehumidification module is activated, with indoor dew point temperature as the main control parameter (dew point deviation ΔT_dp≈2℃, independent dehumidification module operates at full load); the chilled water supply temperature is moderately increased within the range defined in the claims, and the chiller COP is significantly improved; the condensation heat of the independent dehumidification module is used for reheating (replacing electric heating and saving more than 60% of electric heating power), and the cooling capacity is used for deep condensation and dehumidification of the purified air through the refrigerant evaporation coil; the temperature of the purified area is controlled by the chilled water flow rate and the reheat heat of the purified air (the opening of the proportional integral valve), and the humidity is controlled by the independent dehumidification module, with temperature and humidity decoupled; S4. Strictly mutually exclusive operation: When the independent humidification module stops, the humidification start signal is forcibly locked to "stop," and the state machine level constitutes a single state of "dehumidification operation," with no transition period between the two. The independent humidification module's circulating water pump stops, the waste heat recovery pipeline electric valve closes, and the preheating coil of the wet curtain is not used, resulting in an overall state of shutdown, power outage, and water outage; Special Circumstances Handling: When the outdoor dew point rises to 33°C or above before heavy rain, temporarily adjust the fresh air / exhaust air volume in the purification area (reduce the fresh air frequency and exhaust air frequency) to reduce the total moisture load entering the room, and maintain full-load operation of the independent dehumidification module; Results: The energy efficiency ratio is significantly improved after the chiller water supply temperature is moderately increased within the range specified in the claims; the energy consumption of electric heating reheat is reduced by more than 60%; the dew point of the air supply in the purification zone is stabilized within the neutral line, and the waste of cooling capacity is reduced by about 30%; the energy consumption of the purification unit interface is significantly reduced; at the same time, the control loops of the two modules are completely independent, and the humidification module stops running, loses power and water during dehumidification operation, and cannot run idle and lose energy.

[0060] Example 2: Overall Humidification Operation in Winter Operating conditions: A tertiary hospital in southern China, with an outdoor temperature of 8°C, relative humidity of 55%, and outdoor dew point temperature of approximately 0°C in winter; the indoor temperature of the cleanroom is set at 24°C, and the dew point temperature is set at 12°C. S1. Parameter Acquisition and Dew Point Calculation: Outdoor weather station collects T... out=8℃, RH out = 55%, according to the Magnus formula, T is obtained. dp out≈0℃; Indoor sensor data collection T in=23.5℃, RH Given in=35%, T is obtained using the rapid estimation method. dp in≈10.5℃; S2. Overall operating condition judgment (based solely on dew point): T dp out=0℃ < T dp set=12℃ → Overall humidification operation; S3. Differentiated control strategy execution (the control loops of the independent dehumidification module and the independent humidification module within the purification subsystem are set independently): Independent humidification module control loop (active): The independent humidification module is activated to preheat and humidify the fresh air; the heat source is hot water (45℃, using hot water coils to heat the fresh air) generated by the independent air-cooled heat pump units (independent of the central air conditioning unit) in each purification zone, or waste heat from the cooling water of the water-cooled air conditioner in the power room (water temperature 30℃, the humidification module's own compressor and heat exchange tank absorb heat from the cooling water, using refrigerant condensate coils to heat the fresh air); the fresh air is preheated to about 24℃ by the water-air heat exchanger and then is enthalpically humidified through a wet film, raising the fresh air dew point to about 12℃; variable frequency circulating water... The pump precisely controls the hot water flow rate based on the preheated fresh air temperature (the refrigerant system controls heat by compressor frequency), ensuring that the heating amount matches the return air temperature requirements (incidentally, it also controls the humidification intensity, but does not participate in active humidity control, i.e., temperature and humidity control are decoupled); the central air conditioning unit does not participate in cooling the clean area in winter, and the cold source for the clean area is handled by the independent air-cooled heat pump units corresponding to each clean area, with hot water coil heating replacing electric heating; the electrode humidifier only provides peak humidification during extreme dry and cold weather, or as a backup humidifier when a new humidification module fails; eliminating the internal heat loss caused by the simultaneous operation of "cooling + electric heating"; Independent dehumidification module control loop (interlocked shutdown state): The dehumidification start signal is forcibly locked to "stop", the refrigeration cycle stops, the electric valve of the evaporator side circuit is closed, and the reheat interface of the condenser side is disabled; S4. Strictly Exclusive Operation: When the independent dehumidification module shuts down, the dehumidification start signal is forcibly locked to "stop," creating a single "humidification operation" state at the state machine level. Since the outdoor dew point is much lower than the indoor set dew point in winter, there is no sudden need for dehumidification during humidification. If the dehumidification module is in refrigerant-water or hot water coil mode for reheating the air, the mode switching three-way valve switches to external heat source mode, providing secondary heating for the air handling unit and coordinating with the primary heating of the humidification module. If the dehumidification module is in pure refrigerant mode, it is in a shutdown and power-off state. Effects: Eliminates internal heat loss, improving system energy efficiency by approximately 40%; hot water coil heating replaces electric heating, increasing the energy efficiency ratio from 1.0 to over 3.0; reduces electrode humidifier investment by over 70%; if humidification is driven by recovering waste heat from surrounding cold sources, the system energy efficiency ratio is even higher; humidity control oscillations are eliminated, and stability is significantly improved.

[0061] Example 3: Low-intensity, graded operation under overall humidification or dehumidification conditions during the transition season Technical Background: This invention clarifies methodologically that "there are only two overall operating conditions throughout the year—overall dehumidification and overall humidification." The spring and autumn transition seasons do not constitute an independent third operating condition, but rather belong to the low-intensity grading stage of their respective overall operating conditions. Specifically: during the spring temperature rise, the outdoor dew point is generally still lower than the indoor set dew point, belonging to the low-intensity grading stage of the overall humidification condition; during the autumn temperature drop, the outdoor dew point is generally higher than the indoor set dew point, belonging to the low-intensity grading stage of the overall dehumidification condition. Two sub-examples (3a, 3b) are shown respectively.

[0062] Example 3a: Spring - The transitional season from cold to hot (belonging to overall dehumidification conditions - low intensity classification L0-L1) Operating conditions: Taking Foshan as an example, in spring (from late February to mid-April), the outdoor temperature is 15-30℃, the relative humidity is 60-95%, and the outdoor dew point temperature is about 10-22℃; the indoor temperature of the clean area is set at 24-25℃ and the dew point is set at 12℃. S2 Static External Dew Point Comparison: T dp spring temperature ≈ 10-21℃, T dp set = 12℃ → The outdoor dew point is generally higher than the indoor set dew point. The temperature is low and the humidity is high in this season, so it is judged as the overall dehumidification condition (it does not constitute an independent condition in spring and the humidification module will not be activated). S3 Two-wire parallel independent control: • Humidity control line: The independent dehumidification module is put into operation, and the independent humidification module is forcibly locked into a shutdown state by the operating condition interlock; the humidity line switches in real time between L0 (shutdown hold) and L1 (relative low power) based on the dynamic internal comparison results between the actual indoor dew point and the set dew point. When the actual indoor dew point is slightly lower than the set dew point, the module temporarily stops (enters L0); when it is higher than the set dew point, it dehumidifies at a relatively low power (enters L1); the humidification module is not started under any circumstances. • Temperature control line: The chilled water of the air-cooled module is adjusted independently in real time as needed (the water supply temperature is moderately raised above the traditional lower limit value according to the range described in weight 6, and the machine can be shut down in cold weather) to stabilize the temperature of the purification zone at 25-26℃; the humidity line and the temperature line are synchronized in time and do not interfere with each other in space. Key points of handling: In spring, there may be short-term events where cold air from the north moves southward, causing a sudden drop in outdoor temperature and relative humidity. However, the South China region is generally in the period of humid weather and plum rains, requiring dehumidification. Since the humidity line of the independent dehumidification module in the purification area has converged independently to the set dew point, the actual indoor relative humidity is stably controlled within the set fluctuation bandwidth (55-60% in this project as an example), and short-term periods below 55% are allowed but not below 50%. Even if the humidity line is in the L0 shutdown state during a certain period in autumn, the humidification module will not be activated. The occasional "light humidification demand" in autumn is attributed to the overall dehumidification condition being downgraded to L0 (module temporary shutdown) rather than the activation of the reverse module at the methodological level of this invention, thus eliminating the repeated alternation of dehumidification and humidification from the source.

[0063] Example 3b: The transitional season from hot to cold - autumn (belonging to the overall humidification condition - low intensity classification L0-L1) Operating conditions: Taking Foshan as an example, in autumn (approximately late October to the end of November), the outdoor temperature is 12-30℃, the relative humidity is 43-80%, and the outdoor dew point temperature is approximately 2-18℃; the indoor temperature of the clean area is set at 25-26℃, and the dew point is set at 12℃. S2 Static External Dew Point Comparison: T dp out (autumn) ≈ 2-18℃, T dp set = 12℃ → The outdoor dew point is generally higher than or close to the indoor set dew point. This season is judged as the overall humidification condition (this does not constitute an independent condition in autumn and the dehumidification module will not be activated). S3 Two-wire parallel independent control: • Humidity control line: The independent humidification module is put into operation, and the independent dehumidification module is forcibly locked into a shutdown state by the operating condition interlock; the humidity line switches in real time between L0 (shutdown hold) and L1 (low power) based on the dynamic internal comparison results between the actual indoor dew point and the set dew point. When the actual indoor dew point is slightly higher than the set dew point, the module temporarily stops (enters L0); when it is slightly lower than the set dew point, low power humidification is applied (enters L1); the dehumidification module is not started under any circumstances. • Temperature control line: Each cleanroom zone is independently adjusted in real time as needed by its corresponding independent air-cooled heat pump unit to stabilize the temperature of the cleanroom zone at 24-25℃; the humidity line and temperature line are synchronized in time and do not interfere with each other in space. Key points of handling: Occasionally, cold air from the north may move southward in autumn, causing short-term events such as a sudden drop in outdoor temperature and a sudden increase in relative humidity. However, since the humidity line of the independent humidification module in the purification area has converged independently to the set dew point, the actual indoor relative humidity is stably controlled within the set fluctuation bandwidth (50-55% in this project as an example), and short-term fluctuations above 55% are allowed but not above 60%. Even if the humidity line is in the L0 shutdown state all day on a certain day in spring, the dehumidification module will not be activated. The occasional "mild dehumidification demand" in autumn is attributed to the classification of the overall humidification condition down to L0 (module temporary shutdown) rather than the activation of the reverse module at the methodological level of this invention, thus eliminating the repeated alternation of humidification and dehumidification from the source.

[0064] Operation and maintenance preparation sequence for seasonal phase transition (level downgrading within the same overall operating condition vs. cross-phase module operation and maintenance preparation) Seasonal transitions can occur in two ways: • Within the same overall operating condition, the humidification intensity is increased or decreased (e.g., switching from low-intensity overall dehumidification in spring to high-intensity overall dehumidification in summer, or switching from low-intensity overall humidification in autumn to low-to-high-intensity overall humidification in winter): No module maintenance intervention is required. The humidification intensity is increased from low-intensity level L0 / L1 to high-intensity level L3 / L4 within the same operating module. The humidity and temperature lines still operate independently in parallel. The electrical interlocking status and physical installation status of the two modules remain unchanged. • Maintenance preparation for transitioning between overall operating conditions: The independent dehumidification module (embedded in the space occupied by the original integrated heat exchange coil of the purification air handling unit) and the independent humidification module (externally installed on the upstream side wall of the fresh air duct valve) have an asymmetry in physical installation. The independent dehumidification module, being embedded inside the purification air handling unit, is difficult to disassemble and remove during stable operation and must remain stationary in the unit. The independent humidification module, being an external branch, can be seasonally installed and removed using flexible ducts and blind flanges. Therefore, during the stable overall dehumidification phase (such as summer), the independent humidification module is physically removed due to power and water outages (water and electricity duct interfaces are disconnected, the wet curtain water tank is emptied, the module is removed from the unit, and a comprehensive inspection and maintenance process is initiated). During the stable overall humidification phase (such as winter), the independent dehumidification module remains in the unit without activating the dehumidification function (its condenser-side hot water coil can passively utilize external heat sources for secondary heating under the "refrigerant + water scheme"), and simultaneously enters the comprehensive inspection and maintenance process. The core task of switching between different overall operating conditions (such as switching from overall dehumidification to overall humidification in autumn, or from overall humidification to overall dehumidification in spring) is not "automatic electrical switching during operation", but "module maintenance preparation and physical installation status switching during the seasonal transition period". Specifically, it is executed in the following order: "deactivate the currently running module - after module maintenance inspection / installation and disassembly (both modules are installed in place during the transition period, one in use and one on standby) - then activate the reverse module". During the transition, there is at least a transitional downtime period in which both modules are stopped. Dehumidification and humidification will never be running simultaneously. For details, see the "Maintenance Supplement: Seasonal Physical Disassembly and Assembly Differentiation Scheme" section of Example 4.

[0065] The fundamental difference from existing enthalpy-humidity map zoning routes This switching sequence differs fundamentally from the existing enthalpy-humidity chart zoning routes (CN202511767732, etc.) "automatic switching of three-season mode": the existing enthalpy-humidity chart zoning routes treat spring and autumn as an independent third operating condition (transitional state), and humidification and dehumidification may run in parallel under the transitional state; this invention clearly states that "there are only two major overall operating conditions throughout the year, and spring and autumn belong to the low-intensity grading stage of the corresponding overall operating conditions respectively". Under the spring and autumn operating conditions, humidification and dehumidification are interlocked at the hardware level, and the reverse module will not be activated under any circumstances, thus eliminating the risk of parallel operation under the transitional state from the methodological root.

[0066] Example 4: Year-round operation plan for an integrated system of independent dehumidification and humidification modules Background: A hospital's cleanroom air conditioning system is equipped with both independent dehumidification and humidification modules, while retaining the original chilled water coil module, electrode humidifier, and electric heating module. This constitutes a progressive retrofit system where "the new module handles the base load + the original equipment handles peak shaving and emergency response." The set temperature for the cleanroom area is 22~26℃, and the set dew point temperature is 12℃.

[0067] Overall dehumidification operation in summer: Steps S1-S2 are the same as in Example 1, and the dew point judgment result is the overall dehumidification condition; The S3 cleanroom implements a two-stage cooling capacity division and self-generated reheat (including a dual-track system of "pure refrigerant solution" and "refrigerant + water solution"): • First stage (original chilled water coil of the clean air handling unit): The chilled water supply temperature of the main unit is allowed to be raised above the traditional lower limit to the range described in weight 6. The chilled water coil pre-cools the air mixed with indoor return air from its initial state (typically 26~30℃ / medium humidity) to 14~18℃ / RH≥90%, undertaking the pre-cooling load mainly for sensible heat cooling and supplemented by condensation dehumidification. • Second stage (independent dehumidification module refrigerant evaporator): The evaporation temperature is controlled at 5℃ (below the dew point and above 2℃ to prevent surface condensation from freezing), deeply condensing and dehumidifying the low-temperature, high-humidity air pre-cooled by the first stage to saturation. • Reheat (condenser side of independent dehumidification module): Choose one of the following two paths or combine them according to the actual project requirements— Pure refrigerant solution: The refrigerant condenser coil of the independent dehumidification module is placed directly in the reheat section of the airflow channel after deep dehumidification, and the air after deep dehumidification is directly DX condensed and reheated to the supply air state - simple and direct, direct use of heat, no intermediate heat exchange links; Refrigerant + Water Solution: The hot water coil of the independent dehumidification module is placed in the reheat section of the airflow channel after deep dehumidification. The refrigerant condensation heat is used to heat the circulating water to 38~42℃ via a water-cooled heat exchange tank. After the circulating water enters the hot water coil, it heats the deeply dehumidified air to the same humidity level and then to the air supply state. When there is too much reheat heat, hot water can be supplied to the outside through the external interface. The refrigerant condensation temperature is limited by the water temperature to protect the compressor and maximize the deep dehumidification capacity of the refrigerant evaporation coil. • The original electric heating module of the blower unit is retained and will only be put into emergency use in case of heating coil failure.

[0068] Overall humidification operation in winter: Steps S1-S2 are the same as in Example 2, and the dew point determination result is the overall humidification condition; S3 cleanroom area implements stepped heating base load: • Primary heating (independent humidification module, preheating coil before the evaporative cooling pad): Utilizing waste heat recovery (45°C hot water generated by the independent air-cooled heat pump units corresponding to each purification zone during heating operation, or heat absorption from the circulating water in the cooling zone by a refrigerant compressor) to preheat the dry, cold outdoor fresh air (around 5-12°C) to approximately 22°C in winter, bearing the main base load for air heating in winter; the preheated fresh air then enters the evaporative cooling pad section for isenthalpic humidification. • Secondary heating (independent dehumidification module hot water coil, only provided under the "refrigerant + water solution"): The internal refrigeration cycle of the independent dehumidification module stops, and the condenser side does not generate its own heat source; the mode switching three-way valve switches to the external heat source connection mode, and the 45~50℃ hot water generated by the external air source heat pump unit flows into the hot water coil through the external interface (without passing through the water-cooled heat exchange tank), or through the refrigerant four-way valve to convert the refrigerant evaporation coil into a refrigerant condensation coil (the cooling capacity is carried to other areas that need cooling in winter through the external circulating water to achieve combined cooling and heating), and reheats the mixed air after primary heating and isenthalpic humidification, so that the return air temperature and humidity reach the qualified range. • The cooling source of the clean area is provided by the independent air-cooled heat pump unit (independent of the central air conditioning unit) corresponding to each clean area. The central air conditioning unit is shut down for maintenance in winter. The independent air-cooled heat pump unit can be shut down in low temperature and low humidity weather, eliminating the phenomenon of internal heat loss due to excessive cooling in low temperature weather. • The original electric heating module can be retained after being configured with reduced power as an auxiliary rapid peak-shaving heating component for extreme cold weather in winter, and can only be put into short-term supplementary heat when the outdoor temperature drops sharply or the base load of the two-stage heating is temporarily insufficient. • The original electrode humidifier will be retained, and will only be used as an emergency humidification component when the independent humidification module fails and stops operating; it will not be used as a regular humidification method. S4 Strictly Mutually Exclusive Operation: The independent dehumidification module (summer operation) and the independent humidification module (winter operation) are strictly mutually exclusive, forming an electrical transient interlock at the control logic level, and simultaneously forming a physical maintenance mutual exclusion at the seasonal scale (see the "Maintenance Supplement: Seasonal Physical Disassembly and Assembly Differentiation Scheme" section of this embodiment for details); the spring and autumn transition seasons are handled according to the "belonging to the low-intensity classification stage of the corresponding overall operating condition" as described in Embodiment 3 (autumn belongs to the overall humidification operating condition L0-L1, spring belongs to the overall dehumidification operating condition L0-L1, and the reverse module is not started under any circumstances). When switching between overall operating condition stages, the sequence is "first stop the current module - after module maintenance check / installation and disassembly in place - then start the reverse module". During the switching process, there is at least a transitional shutdown period in which both are stopped.

[0069] Effect: In summer, the two-stage cooling capacity division of labor raises the main unit's water supply temperature within the range described in Article 6, significantly improving the main unit's COP; the independent dehumidification module generates its own reheat (either a pure refrigerant solution or a refrigerant + water solution can be used), completely eliminating the energy consumption of the original electric heating reheat; the original chilled water coils serve as the main cooling source, retaining the original equipment investment; In winter, the tiered heating base load covers basic heating needs with a first stage (waste heat preheating) + a second stage (external heat pump hot water reheating). The original electric heating is downgraded and only used for rapid peak adjustment. The overall heating energy consumption is reduced by about 65% compared to the traditional pure electric heating solution. The original electric heating, original chilled water coil, and original electrode humidifier are all retained and their roles have been redefined. There was no one-size-fits-all removal and replacement. The original emergency redundancy is fully retained. This embodiment also verifies the synergistic energy-saving effect of using "independent dehumidification module + independent humidification module" in combination compared to single-module retrofit, the engineering feasibility of the "gradual retrofit" concept, and the engineering compatibility of the "pure refrigerant solution" and "refrigerant + water solution" dual-track system during summer reheat.

[0070] Operations and maintenance supplement: Seasonal physical disassembly and assembly differentiation solutions: The independent dehumidification module and the independent humidification module described in this invention have an asymmetry in their physical installation. The independent dehumidification module is embedded in the space occupied by the original integrated heat exchange coil of the purification air handling unit, forming a permanent component inside the purification air handling unit. The independent humidification module is externally installed, connected to the upstream side wall of the fresh air duct valve of the purification air conditioning subsystem via a flexible duct and a round-to-square connecting air outlet, forming a detachable branch outside the purification air handling unit. Based on this asymmetry in physical installation, this embodiment provides a differentiated seasonal operation and maintenance scheme for the two modules under year-round operation, constituting a mutually exclusive supplement to the seasonal physical operation and maintenance mutual exclusion of the electrical interlocking described in claim 18.

[0071] Stable overall dehumidification phase (e.g., summer): The independent dehumidification module starts operating and assumes the humidity control load; the independent humidification module is in a physical shutdown state with power and water supply cut-off—the electrical circuit start signal is interlocked and forcibly locked to "stop," further executing physical maintenance actions such as "disconnecting the water circuit interface, emptying the wet curtain water tank, stopping and de-energizing the circulating water pump, closing the electric valve of the waste heat recovery pipeline, installing blind flanges to seal the connection ports of the fresh air duct and flexible air duct, and removing the entire module from its position," and entering a comprehensive inspection and maintenance process (including wet curtain descaling / water circuit leak detection / air valve and blind flange inspection). At this stage, the independent humidification module is in a complete physical shutdown state of "electrical shutdown + water and air duct disconnection + unit removal + entering comprehensive maintenance."

[0072] Stable overall humidification phase (e.g., winter): The independent humidification module starts operating to handle humidity control (including fresh air preheating + isenthalpic humidification); the independent dehumidification module remains in its location without dehumidification function—the refrigeration cycle is shut down, the evaporator-side circuit electric valve is closed, and the condenser side does not act as a self-generated heat source; however, the condenser-side hot water coil of the independent dehumidification module passively utilizes an external heat source as a secondary heating component under the "refrigerant + water scheme" (the mode switching three-way valve switches to the "connect to external heat source" mode, and external waste hot water or heat pump hot water flows back into the hot water coil inlet through the external interface), simultaneously entering a comprehensive inspection and maintenance process (including evaporator coil cleaning / water-side circuit leak detection / compressor maintenance). During this stage, the independent dehumidification module is in a mixed state of "dehumidification function locked down + location retained + passive utilization of hot water coil + entering comprehensive maintenance".

[0073] The handover period between different overall operating conditions (such as late autumn / early winter, late spring / early summer): During the handover period, both modules are in the installed position and the water, electricity and air ducts are connected and in place. The independent humidification module is put back into the unit from the exit state (the wet curtain water tank is refilled, the water, electricity and air duct interfaces are reconnected, the blind plate is removed, and the module is returned to its original position). The independent dehumidification module is switched back from the passive use state of secondary heating to its own operation preparation state. Under the electrical interlock protection, the two modules are executed in the order of "first stop the currently running module → after the set transition shutdown period → start the reverse module". During the handover period, although the two modules are physically in the unit, they are still strictly mutually exclusive at the electrical level (one is in use and the other is standby). At any given time, only one of them is in the start state.

[0074] The aforementioned "seasonal physical disassembly and assembly differentiation scheme" and the electrical interlock described in claim 18 constitute a complete two-layer mutual exclusion system of the present invention: "electrical transient interlock (second-level action) + seasonal physical maintenance mutual exclusion (disassembly / removal from the unit)." The electrical layer interlocks at the second-level action level, while the physical layer mutually excludes disassembly and assembly at the seasonal scale. This ensures that at any given moment, only one of the two components actually participates in the operation of the air-conditioning system, fundamentally eliminating the technical possibility of repeated alternation between humidification and dehumidification. This seasonal disassembly and assembly differentiation scheme has both dual engineering benefits: it reduces the electrical standby energy consumption, water circuit crosstalk risk, and component wear of non-operating components through seasonal physical withdrawal, while ensuring the long-term operational reliability of the module through comprehensive inspection and maintenance once per season. This constitutes the unique engineering feature of the present invention, distinguishing it from conventional "equipment always-online" maintenance schemes.

Claims

1. Claim 1 (Independent claim – Method) A seasonally differentiated energy-saving control method for air conditioning systems based on the retrofitting of old cleanroom air handling units. The method is applied to the modified air conditioning subsystem for purification, which only serves the purification area and whose external interface is physically independent from the space outside the purification area. The purification area is sensitive to both temperature and humidity. The purification air conditioning subsystem includes a fresh air duct, a return air duct, an outlet air duct, a purification air handling unit, and an independent decoupling circuit and interlocking relays connecting the aforementioned components. The object of the modification is the air handling unit and its fresh air duct of the air purification and air conditioning subsystem. The modified air conditioning and purification subsystem includes the following hardware structure: The newly added independent dehumidification module adopts an embedded installation structure and is embedded in the space between the original cold water coil and electric heating of the purification air cabinet. It is independent of the original cold water coil and electric heating and is dedicated to the dehumidification of water vapor condensation and air reheating of the purification air cabinet. The newly added independent humidification module adopts an external installation structure. It has a hole on the upstream side wall of the fresh air duct valve of the purification air cabinet and is connected through a flexible air duct and a round-to-square connecting air outlet. The module has a built-in centrifugal fan to actively pressurize and deliver air. The original fresh air return path is not interrupted. It has dual sources connected in parallel and merges. It is equipped with a blind plate that can be switched seasonally. It is independent of the original electrode humidifier and is dedicated to the preheating and isenthalpic humidification of fresh air in the purification area. Independent air duct system, including: air inlet, temperature and humidity control, fan, and ductwork (as needed). The independent dehumidification module draws in purified air from the air handling unit under negative pressure through the inlet. The air first passes through a refrigerant evaporator coil for cooling, causing water vapor to condense and dehumidify. Then, it passes through a heating coil for heating, further reducing relative humidity. Finally, the air is pressurized by the fan and delivered to the air handling unit's outlet duct, thus achieving dehumidification. The independent humidification module draws in fresh outdoor air under negative pressure through the inlet. The air first passes through a coarse filter, then through a heating coil for heating, then through a wet curtain for humidification, increasing relative humidity. Finally, the air is pressurized by the fan and delivered to the air handling unit's fresh air inlet through a flexible duct, thus achieving humidification.

2. An independent decoupling loop connecting the independent dehumidification module, the independent humidification module and the independent air duct of the purification area, the independent decoupling loop including a circulating water pipeline, a circulating water pump, a mode switching three-way valve and an external interface, which undertakes the energy cascade utilization of condensation heat reheat, waste heat recovery humidification and external heat source access; An interlocking relay is installed in the electrical control circuit between the start signal of the independent dehumidification module and the start signal of the independent humidification module, forcibly locking the two from being powered on simultaneously at the hardware electrical circuit level; Its characteristic is that it includes the following steps: S1. Real-time acquisition of outdoor air temperature and relative humidity, calculation of outdoor air dew point temperature; real-time acquisition of air temperature and relative humidity of return air from the clean air handling unit, calculation of indoor dew point temperature in the clean area. S2. The outdoor air dew point temperature is used as the sole criterion for seasonal operating condition switching and overall humidity treatment direction. Enthalpy, temperature-humidity composite parameters, or other seasonal mode judgment parameters are not introduced. Based on the comparison between the outdoor air dew point temperature and the set dew point temperature of the clean area, the overall humidity treatment direction of the current operating condition is determined: when the outdoor dew point temperature is higher than the set dew point temperature, it is determined to be an overall dehumidification operating condition; when the outdoor dew point temperature is lower than the set dew point temperature, it is determined to be an overall humidification operating condition; there is no transitional state between the overall dehumidification operating condition and the overall humidification operating condition where dehumidification and humidification are performed simultaneously. S3. Within the air conditioning subsystem, the control loops of the independent dehumidification module and the independent humidification module are set to be independent of each other, and a temperature and humidity decoupling and differentiated control strategy is implemented—the humidity control line and the temperature control line are independent of each other, controlled in parallel, and do not alternate. The humidity control line uses the return air dew point temperature of the purification air handling unit as the sole criterion and switches the start and stop of the independent dehumidification module (under overall dehumidification conditions) and the independent humidification module (under overall humidification conditions) as needed. The humidity control line does not consider the temperature status in the decision-making process, but only adjusts the start and stop of the module and the level based on the comparison between the actual indoor dew point and the set dew point. The condensation waste heat is used as a by-product for reheating through an independent decoupling loop and does not participate in the humidity decision-making. The temperature control line uses the return air temperature of the purification air handling unit as the criterion, and adjusts the cooling capacity of the original chilled water coil (cooling) and the heating capacity of the heating coil of the independent dehumidification module / independent humidification module (heating) as needed. The control loops of the two modules, apart from sharing the same operating condition judgment result, are physically independent at the hardware level and operate completely independently at the control logic level, without coupling or switching between them; when the actual indoor dew point and the actual indoor temperature reach their respective set values, the corresponding relative humidity will naturally meet the standard, as detailed below: Under overall dehumidification conditions, the independent dehumidification module control loop is activated: the humidity control line uses the independent dehumidification module to handle the basic load of dehumidification in the clean area. The original chilled water coil of the clean air handling unit mainly handles the temperature control load (with incidental condensation dehumidification effect, actually handling the peak load of dehumidification). The chilled water supply temperature in the original chilled water coil is allowed to be increased, reducing the condensation dehumidification effect during cooling, thus decoupling temperature control from humidity control; simultaneously, the independent humidification module and its control loop are completely shut down due to water and power outages. The temperature control line adjusts the opening of the proportional integral valve on the chilled water pipe of the original chilled water coil of the clean air handling unit to control the cooling capacity of the air, and adjusts the opening of the proportional integral valve on the hot water pipe flowing to the outside of the dehumidification module to control the heat of air reheating (if the independent dehumidification module is equipped with a water-cooled heat exchange tank, circulating water pump, valve group, etc.). Under overall humidification conditions, the independent humidification module control loop is activated: the humidity control line uses the independent humidification module to preheat and isenthalpically humidify the fresh air in the purification air handling unit, reducing or eliminating the investment of the original electrode humidifiers in the purification area. The central air conditioning unit does not participate in cooling the purification area in winter. The cold source of the purification area is instead undertaken by the independent air-cooled heat pump unit (independent of the central air conditioning unit) corresponding to each purification area, eliminating the internal heat loss caused by the original "continuous cooling of the main unit + electric heating to compensate for the temperature rise" operation. At the same time, the independent dehumidification module control loop is forcibly locked to the shutdown state by the operating condition interlock, and its refrigeration cycle is shut down, the electric valve of the evaporator side circuit is closed, and the reheat interface of the condenser side is disabled. S4. The independent dehumidification module and the independent humidification module operate strictly mutually exclusively, forming a physical interlock at the control logic level. At any given time, only one of the independent dehumidification module and the independent humidification module is allowed to be in the start state. Simultaneous operation of the two is prohibited, and no transitional operation mode for parallel operation is set. Under the overall dehumidification condition, only the independent dehumidification module operates, and under the overall humidification condition, only the independent humidification module operates. The humidity in the purified area is allowed to fluctuate within a safe range without triggering reverse operation. Among them, the "using outdoor dew point temperature as the sole criterion" in step S2, the "independent setting of control loops for independent dehumidification modules and independent humidification modules within the purification air conditioning subsystem and differentiated control of temperature and humidity decoupling" in step S3, and the "strictly mutually exclusive physical interlocking operation of independent dehumidification modules and independent humidification modules" in step S4 are implemented together as an inseparable whole technical feature combination. The absence of any one of them does not constitute the complete technical solution of this invention.

3. Claim 2 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S2, under overall dehumidification mode, the independent dehumidification module uses the indoor dew point temperature of the purified area as the main control parameter, and adjusts the cooling output of the dehumidification module in stages according to the deviation between the indoor dew point temperature and the set dew point temperature; under overall humidification mode, the independent humidification module uses the indoor dew point temperature of the purified area as the main control parameter, and adjusts the heating power and humidification amount of the humidification module in stages according to the deviation between the indoor dew point temperature and the set dew point temperature.

4. Claim 3 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, under overall dehumidification conditions, the condensation heat generated by the independent dehumidification module during operation is mainly used for reheating the air in the purified area, replacing the original electric heating reheating device (the energy efficiency ratio is increased from 1.0 for electric heating to over 3.0 for heat pump heating); the cooling capacity generated by the independent dehumidification module during operation is used to perform deep dehumidification of the water vapor in the filtered and cooled purified air inside the air handling unit through the refrigerant evaporation coil, thereby allowing the original chilled water temperature of the purified air handling unit to be moderately increased, thereby reducing the load on the external cooling host and improving energy efficiency.

5. Claim 4 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, under the overall humidification condition, the independent humidification module uses a heating coil to preheat the fresh air: its heat source is one or a combination of the following—hot water generated during the operation of the air-cooled module, and waste heat carried by the cooling water of the water-cooled air conditioner in the power room; the heating coil can be either a hot water heating coil or a refrigerant condensation heating coil; after the fresh air is preheated, it enters the wet film humidification section for isenthalpic humidification. The higher air temperature after preheating accelerates the evaporation of moisture on the surface of the wet film and improves the humidification efficiency.

6. Claim 5 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 4 is characterized in that: The heat supply of the independent humidification module is precisely controlled by the frequency conversion adjustment or start / stop control of the variable frequency circulating water pump through the temperature control line, or the opening degree adjustment of the proportional integral valve, or the frequency conversion adjustment or start / stop control of the refrigerant variable frequency compressor.

7. Claim 6 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, under the overall dehumidification condition, the setpoint of the chilled water supply temperature of the central air conditioning unit is increased from the traditional 5-7℃ to 7-12℃. Due to the increase in supply water temperature, the chiller energy efficiency ratio is significantly improved. The purification area is undertaken by an independent dehumidification module to bear the basic dehumidification load. The cooling capacity of the central air conditioning unit or air-cooled module is freed from the main dehumidification task to focus on temperature control, and incidentally has the effect of peak dehumidification load.

8. Claim 7 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, the control loop of the independent dehumidification module and the control loop of the independent humidification module are each configured with their own start / stop signals, their own circulating water loop, and their own air circulation loop interface. Except for sharing the same operating condition judgment result from step S2, the control loops of the two modules are physically independent at the hardware level and decoupled at the control logic level. Under the overall dehumidification condition, the control loop of the independent dehumidification module independently performs the dual-parameter decoupling division of temperature and humidity, and the control loop of the independent humidification module and its circulating water loop are forcibly locked in a disabled state. Under the overall humidification condition, the control loop of the independent humidification module independently performs the division of fresh air preheating and isenthalpic humidification, and the control loop of the independent dehumidification module and its cooling cycle are forcibly locked in a disabled state.

9. Claim 8 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, under the overall humidification condition, the strategy for eliminating internal heat loss in the purification area is as follows: hot water coil heating replaces electric heating, and the energy efficiency ratio is increased from 1.0 for electric heating to more than 3.0 for heat pump heating or hot water heating; the independent humidification module adopts isenthalpic humidification, and no additional heat is injected into the air during the humidification process, so the heating and humidification do not interfere with each other.

10. Claim 9 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S4, the safe humidity fluctuation range is as follows: when the indoor dew point temperature in the clean area fluctuates between 10-14℃, the reverse operation is not triggered; when the dew point temperature deviates from the set value and the duration exceeds the set threshold, the output level of the currently running dehumidification module or humidification module is adjusted, and the reverse operation mode is not switched.

11. Claim 10 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, when the outdoor dew point temperature rises suddenly in special weather conditions under the overall dehumidification operation of the purification area, the air volume of the fresh air and exhaust air in the purification area is temporarily adjusted to reduce the total dehumidification load; the special weather conditions include before heavy rain or rainstorm and after rain in hot weather.

12. Claim 11 (dependent claim) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: It also includes step S5 – continuous monitoring and feedback optimization: continuously monitoring the temperature and humidity of the purification area, the energy consumption of the purification air handling unit, and the operating parameters of the independent dehumidification module and the independent humidification module; dynamically adjusting the flow rate of cold or hot water supplied to the purification air handling unit from the outside and the module output level; continuously optimizing the temperature of cold or hot water supplied to the purification air handling unit from the outside; and achieving continuous optimization of system energy efficiency.

13. Claim 12 (Independent Claim – System) A seasonally differentiated energy-saving control system for cleanroom air conditioning based on the retrofitting of old cleanroom air handling units. The system retrofits the cleanroom air handling units and their fresh air ducts, return air ducts, and outlet air ducts. The retrofitted system is applied to the cleanroom air conditioning subsystem. The cleanroom air conditioning subsystem includes fresh air ducts, return air ducts, outlet air ducts, cleanroom air handling units, and independent decoupling circuits and interlocking relays connecting the aforementioned components, serving only the cleanroom area. The cleanroom area is highly sensitive to both temperature and humidity (non-cleanroom terminal units and their control strategies, water temperature settings, and differentiated cooling / heating control are not within the scope of this invention). The system is characterized by including the following control modules and the following retrofitted hardware structure as the physical implementation basis of the control modules: Control module section: The dew point calculation module calculates the outdoor air dew point temperature and the indoor dew point temperature in the clean area in real time. The operating condition judgment module uses the outdoor air dew point temperature as the sole criterion, without introducing enthalpy, temperature and humidity composite parameters or other seasonal mode judgment parameters. Based on the comparison between the outdoor air dew point temperature and the set dew point temperature in the clean area, it determines whether the current condition is overall dehumidification or overall humidification. There is no transitional state between the two operating conditions where dehumidification and humidification are performed simultaneously. The independent dehumidification control module, through an independent dehumidification dedicated control loop, controls the independent dehumidification module to undertake the dehumidification load of the purification area under the overall dehumidification condition, and makes the chilled water of the central air conditioning unit mainly undertake temperature control. After the deep dehumidification is completed, the independent decoupling loop takes over the condensation heat to implement self-generated reheating of the air after deep dehumidification, forming an independent loop control of the dehumidification function inside the purification subsystem. The independent humidification control module, through its dedicated humidification control loop, is physically independent and uncoupled from the independent dehumidification control module at the control loop level. Under overall humidification conditions, it controls the independent humidification module to preheat and isenthalpically humidify the fresh air in the purification area. Waste heat drives the humidification coil through an independent decoupling loop, and the central air conditioning unit does not participate in cooling the purification area in winter. Instead, the cold source for the purification area is handled by the independent air-cooled heat pump units (independent of the central air conditioning unit) corresponding to each purification area, thus forming an independent loop control for the humidification function within the purification subsystem. The mutually exclusive operation module forms a physical interlock at the control logic level to ensure that the independent dehumidification module and the independent humidification module operate strictly mutually exclusively—only one of them is allowed to be in the start state at any given time, and the two are prohibited from operating in parallel. The humidity in the purified area is allowed to fluctuate within a safe range without triggering reverse operation. The modified hardware structure (serving as the physical basis for the aforementioned control module): The newly added independent dehumidification module is independent of the original central air conditioning unit's chilled water coil and is dedicated to humidity treatment in the purified area, forming the physical actuator of the independent dehumidification control module under dehumidification conditions. The newly added independent humidification module is independent of the original electrode humidifier and is dedicated to the preheating and isenthalpic humidification of the fresh air in the purification area, forming the physical actuator of the independent humidification control module under humidification conditions. The cleanroom has an independent air duct, and the cleanroom air handling unit has three external interfaces: ① Fresh air duct (directly connected to the outside, introducing fresh outdoor air); ② Return air duct (cleanroom area → air handling unit, introducing return air from the cleanroom area); ③ Air outlet duct (air handling unit → cleanroom area, supplying clean air to the cleanroom area). The fresh air duct has a coarse filter at the front end, the cleanroom air handling unit has a pre-filter + medium-efficiency filter, and the air outlet duct has a high-efficiency filter at the end. It is dedicated to the clean air circulation in the cleanroom area and serves as a shared physical execution channel for the independent dehumidification control module and the independent humidification control module to be used in a time-sharing manner through mode switching. Together, they constitute the physical basis for the independent and differentiated decoupling control of the two modules. An independent decoupling loop connects the independent dehumidification module, the independent humidification module, and the independent air duct. It includes a circulating water pipeline, a circulating water pump, a mode switching three-way valve, and an external interface. It undertakes the energy cascade utilization of condensation heat reheat, waste heat recovery humidification, and external heat source access, and constitutes the common physical basis for the energy cascade utilization of the independent dehumidification control module and the independent humidification control module under two operating conditions. An interlocking relay is installed in the electrical control circuit between the start signal of the independent dehumidification module and the start signal of the independent humidification module. It forcibly locks the two modules from being powered on at the hardware electrical circuit level, thus forming the hardware physical implementation basis of the mutually exclusive operation module. The system comprises the following three components: the "dew point as the sole criterion" of the operating condition judgment module; the "dual-module independent differential decoupling control under independent control loop" of the independent dehumidification control module and the independent humidification control module; and the "strict mutual exclusion physical interlock" of the mutually exclusive operation module. These three components are combined as an inseparable whole technical feature to form this system.

14. Claim 13 (Dependent claim – the independent dehumidification module’s ability to generate its own reheat from condensation heat and its interface with external heating) The seasonally differentiated energy-saving control system for air conditioning based on dew point temperature according to claim 12 is characterized in that: The independent dehumidification module has the capability of self-generating reheat from condensation heat and an interface for external heat supply. (a) In the pure refrigerant scheme, the condenser side of the independent dehumidification module refrigeration cycle is directly placed in the air reheat section, and the air after deep dehumidification is directly reheated, which is simple, direct and heat is directly utilized; (b) In the refrigerant + water scheme, the condenser side of the independent dehumidification module's refrigeration cycle is connected to the hot water coil of the air reheat section via the circulating water circuit of the independent decoupling circuit, and the air after deep dehumidification is indirectly reheated with hot water; when there is too much reheat heat, it can be sent out through the external interface of the independent decoupling circuit, the refrigerant condensation temperature is limited by the water temperature to protect the compressor, and the deep dehumidification capacity of the refrigerant evaporation side is maximized.

15. Claim 14 (Dependent claim – External access specification and combined cooling and heating interface capability for independent humidification module) The seasonally differentiated energy-saving control system for air conditioning based on dew point temperature according to claim 12 is characterized in that: The independent humidification module adopts an external installation structure. It has one hole on the upstream side wall of the fresh air duct valve of the purification air conditioning subsystem, and is connected to the air outlet through a flexible air duct and a round-to-square connector. The module has a built-in centrifugal fan to actively pressurize and supply air. The original fresh air return path is not interrupted. The dual sources are connected in parallel to the fresh air duct. The matching blind plate can be switched seasonally. When the heating coil of the independent humidification module is hot water, it has the ability to recover waste heat heat source interface. The heat source is the waste heat carried by the circulating water generated by the independent air-cooled heat pump unit corresponding to each purification zone when it is producing hot water or cooling. The independent humidification module achieves heating-driven humidification by precisely controlling the heat supply through a variable frequency circulating water pump or a proportional integral valve, or achieves "waste heat-driven humidification" by precisely controlling the heat supply by adjusting the refrigerant compressor frequency.

16. Claim 15 (Dependent Claim – Application Rules of Two-Stage Cooling Division and Self-Produced Reheat in Summer) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: under overall dehumidification conditions, a two-stage cooling capacity division and self-generated reheat collaborative processing rule is adopted for the purification area: The first stage of cooling capacity is provided by chilled water from the central air conditioning unit through the chilled water coil of the purification air handling unit. It pre-cools the air after the return air and fresh air of the purification air handling unit from the initial state to a low temperature and high humidity state of 14~22℃ and relative humidity ≥90%. It undertakes the pre-cooling load mainly for sensible heat cooling and supplemented by condensation dehumidification. In fact, it has the effect of undertaking the peak load of air condensation dehumidification, which is particularly obvious in outdoor high temperature and high humidity weather. The second stage of cooling capacity is provided by the independent dehumidification module for deep dehumidification. It further condenses and dehumidifies the low-temperature and high-humidity air after the first stage of pre-cooling to a saturated state, thus undertaking the deep dehumidification load. It actually has the effect of undertaking the basic load of air condensation and dehumidification, which is particularly obvious in outdoor low-temperature and high-humidity weather. The reheating process is achieved by the refrigerant condensing heat exchanger of the independent dehumidification module itself, which transfers heat to the hot water coil via a self-circulating reheating path or a refrigerant + water scheme path. This process heats the deeply dehumidified air to the supply air state with equal humidity. The reheating heat comes directly from the condensing heat of the refrigeration cycle of this module, without the need for external electric heating or additional heat source supply, thus forming a "compressed dehumidification loop self-generated reheat to replace electric reheat". Through the above two-stage division of cooling capacity, the chilled water supply temperature of the central air conditioning unit can be increased from the traditional 5~7℃ to 9~12℃, the condensation dehumidification intensity of the unit is reduced and the energy efficiency ratio is significantly improved; at the same time, the condensation heat of the independent dehumidification module is used for the isohumid reheat of this loop, realizing the dual utilization of cooling and heating capacity.

17. Claim 16 (Dependent Claim – Application Rules for Winter Stepped Heating Base Load) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: Under overall humidification conditions, a single-stage heating base load or a stepped heating base load consisting of a single-stage and a two-stage heating system can be used for the purified area. The rules for applying the heating base load are as follows: The primary heating is undertaken by the fresh air preheating section of the independent humidification module, which preheats the dry and cold outdoor fresh air in winter to create temperature conditions for subsequent humidification and undertakes the main base load for heating the air in the purification area in winter. Secondary heating is undertaken by the independent dehumidification module, which connects to an external heat source through its external interface. The hot water generated by the external heat pump unit flows back into the hot water coil inlet of the independent dehumidification module through the external interface, or it converts the refrigerant evaporation coil into a refrigerant condensation coil through a refrigerant four-way valve (where the cooling capacity is carried to other areas for winter cooling through external circulating water). This reheats the mixed air after primary heating and isenthalpic humidification, and undertakes the auxiliary base load for heating the air in the purified area during winter. The primary and secondary heating are synchronized in time and connected in series along the airflow direction in space, together covering the basic heating needs of the air purifier in winter, avoiding reliance on electric heating or high-power operation of a single hot water coil for reheating in winter.

18. Claim 17 (Dependent Claim – Retention and Downgrading of Original Components) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: The original electric heating module, chilled water coil module, and electrode humidifier of the purification air handling unit are retained and their roles are redefined after the introduction of the independent dehumidification module and independent humidification module, forming a gradual transformation scheme in which "the new module undertakes the base load, and the original equipment is downgraded for peak shaving and emergency response": The original electric heating module is retained and its power configuration is appropriately reduced to serve as a rapid peak-shaving heating load. In extreme outdoor low temperatures and when the two-stage heating base load is temporarily insufficient to supplement heat, or when the heating base load experiences a brief failure, the original electric heating module is put into emergency mode. The original chilled water coil module is retained and used as the main cooling load in summer and the dehumidification and peak-shaving load under extreme high temperature and high humidity conditions, in conjunction with the two-stage cooling capacity division of the independent dehumidification module. The original electrode humidifier will be retained, but will only be used as an emergency humidification component when the independent humidification module fails and stops in winter, and will not be used as a regular humidification method. By retaining and downgrading as described above, the original equipment investment is preserved to the greatest extent possible, avoiding a one-size-fits-all approach of dismantling and replacing equipment.

19. Claim 18 (Dependent Claim – System-Level Operation Rules and Priority Division of Labor) The seasonally differentiated energy-saving control system for air conditioning based on dew point temperature according to claim 12 is characterized in that: The original electric heating module of the purification air handling unit is retained after being configured with reduced power as a heating component for rapid peak adjustment or emergency use; the original cold water coil module is retained as the main cooling component in summer; and the original electrode humidifier is retained as an emergency humidification component in winter. The independent dehumidification module, independent humidification module, original electric heating module, original cold water coil module, and original electrode humidifier are operated in the control system according to the priority of "new modules undertaking base load, and original equipment undertaking peak shaving and emergency response".

20. Claim 19 (Dependent Claim - Criterion Anchor Refinement) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S2, the outdoor air dew point temperature is used as the sole criterion for further limitation as follows: The outdoor air dew point temperature is directly calculated from the real-time collected outdoor dry-bulb temperature and outdoor relative humidity using the Magnus formula or an equivalent dew point calculation formula. The outdoor air dew point temperature serves as the sole input parameter for determining seasonal operating conditions. The control system does not introduce enthalpy parameters for seasonal mode or operating condition zoning, does not introduce composite criteria composed of outdoor temperature and outdoor humidity for seasonal mode or operating condition zoning, and does not introduce pre-defined spring / summer / autumn / winter season labels or date labels as inputs for operating condition switching. All triggering conditions for seasonal operating condition switching are determined by a single comparison relationship between the outdoor dew point temperature and the set indoor dew point temperature of the clean area. The comparison relationship is a single-variable decision logic of "dehumidification if it is greater than the outdoor dew point temperature, humidification if it is less than the outdoor dew point temperature, and maintenance of the current operating condition if it is within the set bandwidth".

21. Claim 20 (Dependent Claim – Spatial Anchor Refinement) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S3, "independent control loop settings and temperature and humidity decoupling differentiated control for the independent dehumidification module and independent humidification module within the air conditioning subsystem" are further defined as follows: The independent dehumidification module is equipped with dedicated start / stop signals, dew point / humidity sensors, an evaporator-side circulating water circuit (or a pure refrigerant refrigeration circuit), a condenser-side reheat interface, and a mode-switching three-way valve branch interface, forming a dehumidification division control circuit independent of the independent humidification module. In this control circuit, humidity is assigned to the independent dehumidification module, while temperature is assigned to the proportional integral valve of the chilled water flow of the original chilled water coil of the purification air handling unit and the proportional integral valve of the dehumidification module supplying external heat in the (refrigerant + water scheme) dehumidification module. The temperature control variable and the humidity control variable are independently PID regulated or graded regulated in the controller and are not coupled to each other. The independent humidification module is equipped with dedicated start / stop signals, a circulating water pump / proportional integral valve, a waste heat recovery heat source interface, a fresh air preheating interface, and a mode switching three-way valve branch interface, forming a humidification division control loop independent of the independent dehumidification module. In the control loop, humidity is assigned to the independent humidification module, while temperature control is jointly undertaken by the fresh air preheating section and the secondary preheating section of the independent dehumidification module. The independent dehumidification module control circuit and the independent humidification module control circuit, apart from sharing the same operating condition judgment result (from step S2), are physically independent at the hardware level and operate completely independently at the control logic level. They are not coupled to each other and do not affect each other. The control circuits of the two modules only share the mutually exclusive enable signal on the interlock relay.

22. Claim 21 (Dependent Claim - Execution Anchor Refinement) The seasonally differentiated energy-saving control method for air-conditioning purification based on dew point temperature according to claim 1 is characterized in that: In step S4, the phrase "strictly mutually exclusive physical interlocking operation of the independent dehumidification module and the independent humidification module" is further defined as follows: The physical interlock is implemented in the control system in one or more of the following ways: (a) the start signal of the independent dehumidification module and the start signal of the independent humidification module constitute Boolean mutual exclusion logic (XOR or interlocking relay) in the controller, and when one of them is "start", the other is forcibly locked to "stop"; (b) the electrical control circuits of the independent dehumidification module and the independent humidification module share the same switching switch or interlocking intermediate relay, and the hardware level prohibits the two from being powered on at the same time; (c) the control system sets up a unified "module operation state machine", which only allows three states: "dehumidification module running - both stopped - humidification module running", and does not allow the state of "dehumidification module and humidification module running at the same time"; The switching process strictly follows the sequence of "first deactivating the currently running module—confirming that the humidity has fallen back to a safe fluctuation range—then activating the reverse module." During the switchover process, there is at least one transitional shutdown period in which both systems stop, but there is never a transitional runtime period in which both systems run in parallel.

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