Water-cooled direct expansion air conditioning unit with constant temperature and humidity function

Abstract

The present application relates to air conditioning unit technical field, specifically to a kind of water-cooled direct expansion air conditioning unit with constant temperature and humidity function, including air pipe and direct expansion evaporator being arranged in the air pipe, the air pipe is equipped with baffle, the baffle is fixedly arranged along horizontal direction, and located downstream of the direct expansion evaporator, the baffle separates into heat exchange air duct and bypass air duct in the air pipe, the heat exchange air duct is located bypass air duct upside.This application can adjust the opening degree of the air valve of heat exchange air duct and bypass air duct according to the dynamic change of condensing pressure of refrigeration system, realize the adaptive matching of air supply flow field and dehumidification load, ensure the dehumidification accuracy and air supply temperature and humidity stability, avoid the waste of air supply fan power consumption caused by excessive air duct resistance under low load condition, and greatly improve the comprehensive energy-saving effect of unit full working condition operation.

Description

Technical Field

[0001] This invention relates to the field of air conditioning unit technology, specifically to a water-cooled direct expansion air conditioning unit with constant temperature and humidity functions. Background Technology

[0002] Water-cooled direct expansion air conditioning units couple a built-in refrigerant circulation loop with the air handling duct to achieve precise control of air temperature and humidity in enclosed spaces. When indoor humidity exceeds the standard, the unit activates its compressor for cooling, using the direct expansion evaporator to cool the passing air to below the dew point temperature, causing the water vapor carried in the air to condense and precipitate, thus achieving dehumidification. However, the air temperature after deep cooling and dehumidification is often far lower than the set target supply air temperature. To maintain a constant indoor temperature, the subsequent electric heater must immediately start at high power for supplemental heating. This operating mode of first subcooling and dehumidifying, then compensating with electric heating, leads to repeated energy waste, increasing the unit's operating energy consumption and costs.

[0003] To address the high energy consumption caused by the offsetting of hot and cold temperatures, those skilled in the art have proposed several improvement solutions. For example, a hot gas reheat system can be introduced. A three-way regulating valve can be added to the compressor's exhaust pipe, and a set of hot gas reheat coils with a fixed area can be connected in parallel in the downstream air duct of the direct expansion evaporator. Under dehumidification and reheat conditions, the flow direction of the refrigerant can be changed by the three-way regulating valve, and part of the high-temperature and high-pressure gaseous refrigerant discharged from the compressor can be introduced into the hot gas reheat coils. The heat released by the refrigerant's own condensation can be used to heat the cold air after dehumidification by the direct expansion evaporator, thereby attempting to replace or partially replace the traditional electric heater.

[0004] However, the physical heat exchange area of ​​traditional hot gas reheat coils is fixed. When the indoor temperature and humidity load fluctuates drastically, simply relying on a three-way regulating valve to adjust the flow rate on the fluid side can easily lead to an imbalance in the refrigerant flow distribution between the main water-cooled condenser and the hot gas reheat coil. When the flow distribution is improper, it can easily cause an abnormal surge in the high-pressure side pressure of the refrigeration system, thereby triggering the high-pressure protection to trip, or resulting in insufficient reheat capacity.

[0005] Therefore, there is an urgent need for a water-cooled direct expansion air conditioning unit that can achieve a purely mechanical adaptive dynamic matching of condensing pressure and reheat. Summary of the Invention

[0006] The purpose of this invention is to provide a water-cooled direct expansion air conditioning unit with constant temperature and humidity functions, in order to solve the problems mentioned in the background art of traditional hot gas reheat water-cooled direct expansion air conditioning units, where the reheat coil with a fixed heat exchange area cannot adapt to load fluctuations, easily causing refrigerant flow imbalance, resulting in system high-pressure protection tripping or insufficient reheat.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A water-cooled direct expansion air conditioning unit with constant temperature and humidity function includes an air duct and a direct expansion evaporator disposed within the air duct. A baffle is provided inside the air duct, fixed horizontally and located downstream of the direct expansion evaporator. The baffle divides the air duct into a heat exchange air duct and a bypass air duct. The heat exchange air duct is located above the bypass air duct and contains a heat exchange coil assembly. A first louvered damper and a second louvered damper are respectively provided on the side of the heat exchange air duct and the bypass air duct furthest from the direct expansion evaporator. The air valve has a sliding valve assembly on the outer wall of the air duct. The sliding valve assembly includes a valve body and a valve core. The valve core is slidably connected to the valve body. One end of the valve body is connected to the high-pressure end of the direct expansion evaporator through a pipe. One end of the valve core extends out of the valve body. The end of the valve core extending out of the valve body is provided with a transmission assembly. The transmission assembly is located inside the air duct and between the heat exchange air duct and the bypass air duct. The transmission assembly is used to convert the sliding of the valve core into reverse adjustment of the opening of the No. 1 louvered air valve and the No. 2 louvered air valve.

[0008] By installing No. 1 and No. 2 louvered air valves in the air duct, which are controlled by a sliding valve assembly and a transmission assembly, when the indoor humidity load increases and the unit is in deep cooling dehumidification mode, the condensing pressure at the high-pressure end of the direct expansion evaporator surges and drives the valve core of the sliding valve assembly to slide through the pipeline. Then, the transmission assembly adaptively adjusts the opening of the No. 1 louvered air valve to increase and simultaneously adjusts the opening of the No. 2 louvered air valve to decrease. This forcibly guides the cold air after dehumidification by the direct expansion evaporator into the upper heat exchange air duct to flush the heat exchange coil assembly. The refrigerant's own condensation waste heat provides high-power supplementary heating for the air, thereby avoiding the problem of traditional units relying on high-energy-consuming electric heaters for heat compensation and effectively reducing the overall operating energy consumption and operating costs. Furthermore, after the temperature and humidity load decreases and the system high-pressure side pressure drops, the valve core can slide in the reverse direction and drive the opening of the No. 1 louvered damper to decrease and the opening of the No. 2 louvered damper to increase through the transmission component. This ensures that under low-load conditions, most of the cold air can pass smoothly through the bypass duct without heat exchange coil resistance, preventing indoor overheating under low load conditions. It also avoids the problem of increased power consumption of the blower due to excessive duct resistance, ensuring the overall energy-saving effect of the unit under various load conditions. Moreover, compared to traditional electrically controlled three-way regulating valves, the slide valve assembly and transmission component of this invention are purely mechanical self-powered structures, directly using condensing pressure as a feedback signal and power source. This reduces the number of electronic sensors and electric actuators, thereby reducing the unit's electrical control failure rate and maintenance costs. Even under extreme conditions where drastic load fluctuations cause a sudden increase in high pressure, the pressure can quickly and safely drop through instantaneous, non-delayed linkage between the air-side and fluid-side, eliminating the risk of high-pressure tripping and facilitating the long-term stable operation of the air conditioning unit.

[0009] Preferably, the heat exchange coil assembly includes a first reheat coil and a second reheat coil. The second reheat coil is located downstream of the first reheat coil. The first reheat coil is normally open-connected to the refrigeration piping system, and the second reheat coil is connected to the refrigeration piping system through a pressure relief valve.

[0010] By setting up a No. 1 reheat coil and a No. 2 reheat coil in the heat exchange duct, and setting the No. 1 reheat coil to be normally connected to the refrigeration piping system, the No. 1 reheat coil provides the basic reheat heat when the air conditioning unit is in normal temperature and humidity control conditions. When the indoor humidity load increases and the system condensing pressure rises sharply, the high-pressure gas inside the system breaks through the set opening threshold of the pressure relief valve and conducts, allowing the high-temperature gaseous refrigerant to flow into the No. 2 reheat coil instantly, realizing the dynamic expansion of the physical heat exchange area. This avoids the problem of insufficient reheat heat under high load caused by the fixed physical heat exchange area of ​​traditional hot gas reheat coils, and effectively prevents the phenomenon of disrupting the constant temperature state of the closed space due to excessively low supply air temperature under dehumidification conditions. Furthermore, since the No. 2 reheat coil is located downstream of the No. 1 reheat coil, the air, after being preheated by the No. 1 reheat coil, continues to flow through the No. 2 reheat coil. This ensures a gradual increase in the temperature gradient between the air and refrigerant sides throughout the entire heat exchange path, avoiding the problem of uneven local heat exchange or drastic temperature fluctuations caused by the high-temperature refrigerant pipeline directly impacting the low-temperature cold air. This guarantees the uniformity and stability of the final supply air temperature. Moreover, compared to schemes using electronic expansion valves or electric three-way regulating valves to control refrigerant distribution, this invention uses a purely mechanical pressure relief valve to control the self-regulating grid connection of the secondary coil. Its hardware architecture does not rely on external power signals, thus significantly reducing the dynamic hysteresis of the control system and the failure rate of electronic components. Even if high-frequency pulsations occur within the refrigeration piping system, the physical threshold of the pressure relief valve facilitates instantaneous spontaneous pressure relief and balance, ensuring the overall operational reliability of the air conditioning unit.

[0011] Preferably, the angle between the lower end face of the first louvered damper and the upper end face of the partition is the first included angle, and the angle between the upper end face of the second louvered damper and the lower end face of the partition is the second included angle. Both the first included angle and the second included angle are located on the side facing the direct expansion evaporator, and both the first included angle and the second included angle are acute angles.

[0012] By setting both angle 1 and angle 2 as acute angles facing the direct expansion evaporator, when air flows out of the direct expansion evaporator and is diverted by the baffle, the inwardly inclined louvered dampers 1 and 2 can guide the airflow on the windward side and slow down the transition. This avoids severe boundary layer separation or turning vortices caused by sudden expansion or contraction at the upper and lower edges of the baffle, effectively preventing increased duct resistance caused by local flow field turbulence, and ensuring the smooth flow of the airflow when it enters the heat exchange duct and bypass duct respectively after diversion. Furthermore, compared with the traditional vertically arranged louvered dampers, the inclined acute angle configuration of this invention reduces the effective facing area of ​​the damper blades directly orthogonally impacted by the high-pressure airflow, thereby significantly reducing the axial stress and high-frequency excitation of the blades and drive shaft caused by airflow pulsation. Even under dehumidification and heat exchange conditions with drastic airflow fluctuations, it can effectively suppress the mechanical vibration and noise of the damper blades, ensuring the rigid structural stability of the internal transmission components.

[0013] Preferably, both the No. 1 louvered damper and the No. 2 louvered damper include a rotating shaft, a connecting part, and a swinging part. The rotating shaft is rotatably connected to the air duct, and the swinging part is located on the downstream side of the connecting part, with the swinging part being heavier than the connecting part.

[0014] By installing a swinging part, heavier than the connection, downstream of the connection point on both the No. 1 and No. 2 louvered dampers, gravity acts on the eccentrically positioned swinging part and spontaneously generates a gravity-based restoring torque when the fan is off or the refrigeration piping system is under low-pressure conditions. This drives the No. 1 and No. 2 louvered dampers to deflect towards their initial reference opening position, effectively preventing cross-flow of hot and cold air caused by improper damper closure during non-dehumidification operations. Furthermore, when the unit is under heavy load performing deep cooling dehumidification and a large volume of cold air impacts the damper blades at high speed, the inherent mechanical inertia of the downstream, heavier swinging part provides dynamic damping and vibration reduction for the blades. This ensures the damper blades' ability to resist severe vibration in a high-speed, unsteady flow field, avoiding high-frequency vibration of the blades caused by high-speed airflow pulsation, which could lead to mechanical fatigue wear or abnormal resonance noise at the shaft connection. This ensures flow stability and quiet operation throughout the entire damper opening adjustment stroke.

[0015] Preferably, a through hole is provided in the middle of the connecting part of the first louvered damper and the middle of the swing part of the second louvered damper. A pull rope is threaded through the through hole and fixedly connected to the through hole. The pull rope on the first louvered damper is the first pull rope, and the pull rope on the second louvered damper is the second pull rope. A first pulley and a second pulley are provided on the side of the partition away from the direct expansion evaporator. The first pulley is located above the second pulley. The first pull rope is slidably connected to the first pulley, and the second pull rope is slidably connected to the second pulley. Both the first and second pull ropes extend to the outside of the duct and are fixedly connected to the end of the valve core that extends to the outside of the valve body.

[0016] By creating through holes in the middle of the connection part of the No. 1 louvered damper and the middle of the swing part of the No. 2 louvered damper, and fixing pull ropes through them, and by setting No. 1 pulley and No. 2 pulleys in the vertical projection of the connection part on the side of the partition away from the direct expansion evaporator, when the system condensing pressure increases and drives the valve core to move, the valve core synchronously pulls the No. 1 pull rope and No. 2 pull rope axially. The pull ropes bypass the corresponding pulleys to change the direction of power transmission and apply tension to the connection part. This avoids the problem of traditional rigid connecting rods being difficult to arrange in the compact space inside the duct and being prone to spatial interference. It also effectively prevents the phenomenon that the damper opening cannot be adjusted in reverse due to local jamming of the transmission components. Furthermore, compared to rigid four-bar linkage mechanisms with bulky structures and large cumulative assembly errors, the pull rope and pulley of this invention form a flexible transmission chain with zero backlash. It is lightweight, occupies little space, and does not interfere with the airflow field in the duct. This significantly reduces the impact of thermal expansion and contraction of components caused by alternating hot and cold air in the duct on transmission accuracy. Even under long-term, frequent, and repeated adjustments in deep-cooling dehumidification conditions, it is easy to eliminate mechanical impact vibrations, ensuring the fatigue life and operational stability of the unit's adaptive shift mechanism.

[0017] Preferably, a sealing layer is provided between the valve core and the inner wall of the valve body, the sealing layer is coaxially fixedly connected to the valve core, and the sealing layer is made of high-temperature resistant polytetrafluoroethylene material.

[0018] By installing a sealing layer made of high-temperature resistant polytetrafluoroethylene (PTFE) that is coaxially and fixedly connected to the inner wall of the valve core and the valve body, the sealing layer can effectively and airtightly isolate the moving contact surface between the valve core and the inner wall of the valve body when high-temperature and high-pressure refrigerant gas from the high-pressure end of the direct expansion evaporator is injected into the valve body cavity. This prevents the high-temperature and high-pressure refrigerant from leaking outwards along the fitting gap or causing pressure loss, effectively preventing the sluggish action or failure of the slide valve assembly due to loss of control power source. Furthermore, because the sealing layer is made of high-temperature resistant PTFE and is coaxially and fixedly connected to the valve core, the extremely low surface friction coefficient and excellent thermal stability of this material ensure that the mechanical friction resistance of the valve core is extremely low when it slides axially back and forth under gas pressure. This avoids the problem of damping surge or even jamming caused by thermal expansion of the sealing material in a high-temperature exhaust environment, ensuring the axial transmission sensitivity and dynamic adjustment accuracy of the slide valve assembly to small fluctuations in the system condensing pressure.

[0019] Preferably, the partition has an internal heat insulation layer made of polyurethane foam insulation material, and the peripheral edge of the partition is rigidly sealed to the inner wall of the duct.

[0020] By setting a heat insulation layer made of polyurethane foam insulation material inside the partition and rigidly sealing the periphery of the partition with the inner wall of the air duct, the partition can construct an efficient heat and fluid barrier between the upper and lower air ducts when the air after dehumidification by the direct expansion evaporator is diverted into the upper heat exchange air duct and the lower bypass air duct. This avoids the problem of high-temperature condensation heat released by the heat exchange coil assembly in the heat exchange air duct being conducted and diffused downwards through the partition, effectively preventing the airflow in the bypass air duct from being ineffectively heated and causing the whole unit to lose heat and cold. Furthermore, since the insulation layer is made of polyurethane foam insulation material and its peripheral edges are rigidly sealed to the inner wall of the duct, the material's excellent low thermal conductivity and dense closed-cell structure ensure that the partition has extremely high thermal resistance and excellent physical boundary airtightness. This avoids the problem of condensation dripping on the partition surface or cross-flow leakage between the two fluids due to the huge temperature difference between the upper and lower air ducts, thus ensuring the targeted accuracy of the airflow field distribution after the diversion and the effectiveness of independent temperature and humidity control. Furthermore, compared to traditional single-layer metal sheet partitions or simple partition structures without edge sealing, the sandwiched foam insulation and rigid sealing composite configuration of this invention not only significantly improves the mechanical bending stiffness of the partition itself, but also endows it with excellent acoustic damping and vibration reduction performance. This reduces the amplitude of elastic deformation or high-frequency resonance of the partition under the alternating impact of high-speed and high-volume airflow, thereby significantly reducing the airflow regeneration noise and structural vibration inside the duct. Even under harsh working conditions such as severe load fluctuations and non-steady-state changes in the dynamic pressure of the two ducts, it is easy to maintain the long-term spatial geometric stability of the duct, ensuring the quiet operation and mechanical fatigue life of the air conditioning unit during continuous operation.

[0021] Preferably, an adjusting nut is coaxially threaded to one side of the valve core extending outside the valve body, and an adjusting spring is coaxially provided on the valve core. The two ends of the adjusting spring are fixedly connected to the outer wall of the valve body and the nut, respectively. The adjusting spring is a tension spring.

[0022] By coaxially threading an adjusting nut to one side of the valve core extending to the valve body, and coaxially setting a tension adjusting spring on the valve core with both ends fixedly connected to the outer wall of the valve body and the nut respectively, when the condensing pressure of the refrigeration system drops and the high-pressure side is depressurized, the adjusting spring in the tensioned state releases elastic potential energy and spontaneously generates a mechanical pull-back torque, driving the valve core and external transmission components to smoothly return to their original position. This avoids the problem of delayed or incomplete return to position caused by uneven damping when the traditional slide valve assembly relies entirely on unidirectional air pressure drive or air-side gravity reset. It effectively prevents the phenomenon of incorrect adjustment of the air valve opening caused by untimely valve core reset under normal operating conditions. Furthermore, since the adjusting nut and the valve core are connected by a coaxial thread, the operator can change the initial pre-tension and elastic restoring force reference of the adjusting spring by rotating the adjusting nut in the axial direction of the valve core. This ensures that the slide valve assembly can adaptively adjust its opening and closing pressure threshold and actuation stroke according to the initial temperature and humidity reference load of different regions or seasons. This avoids the problem of reduced control accuracy or mechanical overload of the air conditioning unit under different operating environments due to the non-adjustable spring stiffness, and ensures the pressure response sensitivity and control flexibility of the unit in diversified application scenarios.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention, by setting up a bypass ventilation duct in conjunction with a self-operated linkage air valve and a slide valve, can automatically and synchronously adjust the opening of the air valves in the heat exchange air duct and the bypass ventilation duct according to the dynamic changes in the condensing pressure of the refrigeration system. This achieves adaptive matching between the airflow field on the air side and the dehumidification load, ensuring both dehumidification accuracy and stability of the supply air temperature and humidity. It also avoids the waste of power consumption of the supply fan caused by excessive air duct resistance under low load conditions, and significantly improves the overall energy-saving effect of the unit under all operating conditions.

[0024] 2. This invention, by setting up reheat coils in stages and using pressure relief valves to control the self-regulating grid connection of the secondary coils, can automatically expand the reheat heat exchange area under high humidity load conditions. It utilizes the high-pressure condensation heat of the system to spontaneously enhance the reheat capacity, which not only avoids the indoor constant temperature state being disrupted by excessively low supply air temperature after dehumidification, but also eliminates the need for additional electrical control and adjustment components, thus improving the reliability of system operation.

[0025] 3. This invention achieves linkage regulation by adopting multiple sets of purely mechanical self-powered structures, directly using the system condensing pressure as the feedback power source, reducing the configuration of electronic sensors and electric actuators. This not only reduces the failure rate and maintenance cost of electrical control, but also enables instantaneous linkage regulation without delay, quickly balances system pressure, eliminates the risk of high-pressure tripping, and ensures the long-term stable operation of the air conditioning unit. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the water-cooled direct expansion air conditioning unit of the present invention; Figure 2This is a schematic diagram of the air duct structure in the water-cooled direct expansion air conditioning unit of the present invention; Figure 3 for Figure 2 Full sectional view at point AA; Figure 4 for Figure 3 A magnified view of a section at point B in the middle; Figure 5 for Figure 4 A magnified view of a section at point C; Figure 6 for Figure 3 Full sectional view at point DD; Figure 7 for Figure 6 A magnified view of a section at point E in the middle; Figure 8 for Figure 6 A magnified view of a section at point F in the middle; Figure 9 This is a schematic diagram of the structure of the louvered air valve in the water-cooled direct expansion air conditioning unit of the present invention.

[0027] In the diagram: 1. Casing; 101. Air inlet; 102. Exhaust outlet; 2. Air duct; 201. Air inlet; 202. Air outlet; 203. Heat exchange air duct; 204. Bypass air duct; 3. Direct expansion evaporator; 4. Baffle plate; 401. Insulation layer; 5. No. 1 reheat coil; 6. No. 2 reheat coil; 7. No. 1 louvered damper; 701. Rotating shaft; 702. Connecting part; 703. Swinging part; 704. Through hole; 8. No. 2 louvered damper; 9. Valve body; 10. Valve core; 1001. Sealing layer; 11. No. 1 pulley; 12. No. 2 pulley; 13. No. 1 pull rope; 14. No. 2 pull rope; 15. No. 3 pulley; 16. No. 4 pulley; 17. Adjusting nut; 18. Adjusting spring. Detailed Implementation

[0028] Please see Figures 1 to 9 This invention provides a water-cooled direct expansion air conditioning unit with constant temperature and humidity functions, the technical solution of which is as follows: Please refer to a water-cooled direct expansion air conditioning unit with constant temperature and humidity functions. Figures 1 to 5 , Figure 8The system includes a casing 1, with an air inlet 101 on the side wall and an exhaust outlet 102 on the upper side. Inside the casing 1 are a compressor, a duct 2, and a direct expansion evaporator 3 housed within the duct 2. The duct 2 has an air inlet 201 and an air outlet 202 at its two ends, respectively. The air inlet 201 connects to the air inlet 101, and the air outlet 202 connects to the exhaust outlet 102. The direct expansion evaporator 3 is connected to the compressor via a pipe joint. A partition 4 is provided inside the duct 2, and an insulation layer 401 is provided inside the partition 4. The insulation layer 401 is made of polyurethane foam insulation material. The periphery of the partition 4... The duct 2 is rigidly sealed to the inner wall of the duct. The partition 4 is fixedly installed in the horizontal direction and is located downstream of the direct expansion evaporator 3. The partition 4 divides the duct 2 into a heat exchange duct 203 and a bypass duct 204. The heat exchange duct 203 is located above the bypass duct 204. The heat exchange duct 203 is equipped with a heat exchange coil assembly, which includes a first reheat coil 5 and a second reheat coil 6. The second reheat coil 6 is located downstream of the first reheat coil 5. The first reheat coil 5 is normally open to the refrigeration piping system, and the second reheat coil 6 is connected to the refrigeration piping system through a pressure relief valve. On the side of the heat exchange duct 203 and the bypass duct 204 away from the direct expansion evaporator 3, there are respectively a No. 1 louvered damper 7 and a No. 2 louvered damper 8. Both the No. 1 louvered damper 7 and the No. 2 louvered damper 8 include a rotating shaft 701, a connecting part 702 and a swinging part 703. The rotating shaft 701 is rotatably connected to the duct 2. The swinging part 703 is located downstream of the connecting part 702. The connecting part 702 and the swinging part 703 have the same length, which is 400mm. The width of the connecting part 702 is 15mm and the width of the swinging part 703 is 20mm. The included angle between the lower end face of the No. 1 louvered damper 7 and the upper end face of the partition plate 4 is the No. 1 included angle. The included angle between the upper end face of the No. 2 louvered damper 8 and the lower end face of the partition plate 4 is the No. 2 included angle. Both the No. 1 included angle and the No. 2 included angle are located on the side facing the direct expansion evaporator 3, and both the No. 1 included angle and the No. 2 included angle are acute angles. A sliding valve assembly is provided on the outer wall of the duct 2. The sliding valve assembly includes a valve body 9 and a valve core 10. The valve core 10 is slidably connected inside the valve body 9. One end of the valve body 9 is connected to the high-pressure end of the direct expansion evaporator 3 through a pipe. One end of the valve core 10 extends outside the valve body 9. A sealing layer 1001 is provided between the valve core 10 and the inner wall of the valve body 9. The sealing layer 1001 is coaxially and fixedly connected to the valve core 10, and the sealing layer 1001 is made of high-temperature resistant polytetrafluoroethylene material. An adjusting nut 17 is coaxially threaded to the side of the valve core 10 extending outside the valve body 9. An adjusting spring 18 is coaxially provided on the valve core 10. The two ends of the adjusting spring 18 are fixedly connected to the outer wall of the valve body 9 and the nut, respectively. The adjusting spring 18 is a tension spring.

[0029] Please see Figures 4 to 9The valve core 10 extends to one end of the valve body 9 and is provided with a transmission component. The transmission component is located inside the air duct 2 and between the heat exchange air duct 203 and the bypass air duct 204. The transmission component is used to convert the sliding of the valve core 10 into reverse adjustment of the opening of the first louvered air valve 7 and the second louvered air valve 8. A through hole 704 is provided in the middle of the connecting part 702. A pull rope is inserted through the through hole 704 and is fixedly connected to the through hole 704. The pull rope on the first louvered damper 7 is the first pull rope 13, and the pull rope on the second louvered damper 8 is the second pull rope 14. The partition plate 4 is provided with a first pulley 11 and a second pulley 12 on the side away from the direct expansion evaporator 3. The first pulley 11 is located at the upper end of the second pulley 12. The first pulley 11 and the second pulley 12 are located in the vertical projection of the connecting part 702. The first pull rope 13 is slidably connected to the first pulley 11, and the second pull rope 14 is slidably connected to the second pulley 12. The first pull rope 13 and the second pull rope 14 both extend to the outside of the air duct 2 and are fixedly connected to the end of the valve core 10 that extends to the outside of the valve body 9.

[0030] Please refer to [link / reference needed] for further information. Figures 5 to 7 A mounting bracket is provided on the side of the partition 4 away from the direct expansion evaporator 3. Pulley 11 and Pulley 12 are rotatably mounted on the mounting bracket. Pulley 11 and Pulley 12 are horizontally arranged. Pulley 3 and Pulley 4 are provided on the side of the mounting bracket away from the partition 4. Pulley 3 and Pulley 4 are vertically arranged. Pull rope 13 is wound around Pulley 11 and then around Pulley 3 and Pulley 4 until the rope end is fixed to the end of the valve stem. Pull rope 14 is wound around Pulley 2 and then around Pulley 3 and Pulley 4 until the rope end is fixed to the end of the valve stem. Furthermore, when it is necessary to adjust the initial state of the louvered damper 7 or the damper 2, only the lengths of pull rope 13 and pull rope 14 need to be adjusted.

[0031] Working Principle: When the water-cooled direct expansion air conditioning unit is put into constant temperature and humidity operation for dehumidification, the direct expansion evaporator 3 absorbs heat from the refrigerant to cool and dehumidify the supply air. At this time, the system condensing pressure will dynamically change with the dehumidification load. Under high humidity and high load dehumidification conditions, the system condensing pressure increases, and the high-temperature and high-pressure refrigerant gas at the high-pressure end of the direct expansion evaporator 3 is injected into the valve body 9, pushing the valve core 10 to move axially against the tension of the adjusting spring 18 towards the air duct 2. The valve core 10 drives the first pull rope 13 and the second pull rope 14 to be pulled synchronously. Under the steering traction of multiple pulleys, the pull ropes drive the first louvered damper 7 and the second louvered damper 8 to rotate synchronously, causing the opening of the first louvered damper 7 located in the heat exchange air duct 203 to increase. As the temperature gradually increases, the opening of the second louvered damper 8 in the bypass ventilation duct 204 gradually decreases, allowing more cooled and dehumidified low-temperature and low-humidity cold air to enter the heat exchange duct 203. At the same time, the second reheat coil 6 automatically connects to the system after the condensing pressure rises to the pressure relief valve's activation threshold, expanding the reheat heat exchange area and using condensation waste heat to reheat and raise the temperature of the dehumidified cold air. This counteracts the excessive cooling and stabilizes the supply air temperature, ensuring a constant indoor temperature and preventing the supply air temperature from being too low after dehumidification, which could affect the accuracy of temperature and humidity.

[0032] When the dehumidification load decreases and the system condensing pressure drops, the internal pressure of valve body 9 decreases. Adjusting spring 18 pulls valve core 10 to reset in the reverse direction, causing the first louvered damper 7 to close slightly and the second louvered damper 8 to open wider. More dehumidified cold air is directly sent out through the bypass ventilation duct 204, reducing the reheat process. At the same time, the pressure relief valve closes, and the second reheat coil 6 is taken out of operation to avoid excessive reheating under low load, maintain stable supply air temperature, reduce duct resistance, and reduce unnecessary power consumption of the blower. The entire adjustment process is powered entirely by the system condensing pressure, and is a purely mechanical self-powered linkage adjustment. It can achieve dynamic adaptive matching of damper opening with dehumidification load without additional electrical control components, ensuring constant temperature and humidity accuracy and achieving energy-saving operation under all working conditions.

[0033] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. A water-cooled direct expansion air conditioning unit with constant temperature and humidity function, comprising an air duct (2) and a direct expansion evaporator (3) disposed within the air duct (2), characterized in that, The duct (2) is equipped with a partition (4), which is fixed horizontally and located downstream of the direct expansion evaporator (3). The partition (4) divides the duct (2) into a heat exchange duct (203) and a bypass duct (204). The heat exchange duct (203) is located above the bypass duct (204). The heat exchange duct (203) is equipped with a heat exchange coil assembly. The heat exchange duct (203) and the bypass duct (204) are connected in a series. 204) A first louvered air valve (7) and a second louvered air valve (8) are respectively provided on one side of the direct expansion evaporator (3) away from the air duct (2). A sliding valve assembly is provided on the outer wall of the air duct (2). The sliding valve assembly includes a valve body (9) and a valve core (10). The valve core (10) is slidably connected inside the valve body (9). One end of the valve body (9) is connected to the high pressure end of the direct expansion evaporator (3) through a pipe. One end of the valve core (10) extends to the outside of the valve body (9). Both the No. 1 louvered damper (7) and the No. 2 louvered damper (8) include a rotating shaft (701), a connecting part (702) and a swinging part (703). The rotating shaft (701) is rotatably connected to the air duct (2). The swinging part (703) is located on the downstream side of the connecting part (702). The swinging part (703) is heavier than the connecting part (702). A through hole (704) is provided in the middle of the connecting part (702) of the first louvered damper (7) and the middle of the swing part (703) of the second louvered damper (8). A pull rope is threaded through the through hole (704) and is fixedly connected to the through hole (704). The pull rope on the first louvered damper (7) is the first pull rope (13), and the pull rope on the second louvered damper (8) is the second pull rope (14). The partition (4) is far away from the direct expansion steam. The generator (3) has a first pulley (11) and a second pulley (12) on one side. The first pulley (11) is located above the second pulley (12). The first pull rope (13) is slidably connected to the first pulley (11), and the second pull rope (14) is slidably connected to the second pulley (12). Both the first pull rope (13) and the second pull rope (14) extend to the outside of the air duct (2) and are fixedly connected to one end of the valve core (10) extending to the outside of the valve body (9).

2. A water-cooled direct expansion air conditioning unit with constant temperature and humidity function according to claim 1, characterized in that, The heat exchange coil assembly includes a first reheat coil (5) and a second reheat coil (6). The second reheat coil (6) is located downstream of the first reheat coil (5). The first reheat coil (5) is normally open-connected to the refrigeration piping system, and the second reheat coil (6) is connected to the refrigeration piping system through a pressure relief valve.

3. A water-cooled direct expansion air conditioning unit with constant temperature and humidity function according to claim 1, characterized in that, The angle between the lower end face of the first louvered damper (7) and the upper end face of the partition (4) is the first angle, and the angle between the upper end face of the second louvered damper (8) and the lower end face of the partition (4) is the second angle. Both the first and second angles are located on the side facing the direct expansion evaporator (3), and both the first and second angles are acute angles.

4. A water-cooled direct expansion air conditioning unit with constant temperature and humidity function according to claim 1, characterized in that, A sealing layer (1001) is provided between the valve core (10) and the inner wall of the valve body (9). The sealing layer (1001) is coaxially fixedly connected to the valve core (10), and the sealing layer (1001) is made of high-temperature resistant polytetrafluoroethylene material.

5. A water-cooled direct expansion air conditioning unit with constant temperature and humidity function according to claim 1, characterized in that, The partition (4) is provided with a heat insulation layer (401) inside. The heat insulation layer (401) is made of polyurethane foam insulation material. The peripheral edge of the partition (4) is rigidly sealed to the inner wall of the air duct (2).

6. A water-cooled direct expansion air conditioning unit with constant temperature and humidity function according to claim 1, characterized in that, The valve core (10) extends to one side of the valve body (9) and is coaxially threaded with an adjusting nut (17). An adjusting spring (18) is coaxially provided on the valve core (10). The two ends of the adjusting spring (18) are fixedly connected to the outer wall of the valve body (9) and the nut, respectively. The adjusting spring (18) is a tension spring.

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