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CN-122029386-A - Air handling unit with carbon dioxide refrigerant circuit, electronic control unit, heating ventilation air conditioning system and method

CN122029386ACN 122029386 ACN122029386 ACN 122029386ACN-122029386-A

Abstract

A method and air treatment unit (50, 100,) 650 having an ECU (800). The ECU includes heat exchange features, a first coil (703) air cooler, a carbon dioxide (R744) refrigerant circuit, and an integrated cooling and heating module with no (700) or carbon dioxide pressure optimization (750). A first coil (703) is placed in the exhaust channel and receives non-heated air from the building. The integrated cooling and heating module is used for heat exchange with a first coil (703) air cooler and a second coil (702), and the second coil (702) is placed in an air supply channel leading to a building (900) by an AHU. When the first coil (703) is placed after the heat exchange function in the exhaust air flow/channel (23), the ECU (800) is able to control or adjust the air temperature (801) at the first coil (703) by regulating the efficiency (53, 103, 303, 503) of the heat exchange function (52). Specific ways of regulation include regulating bypass dampers (53, 103) for bypass channels of a cross flow/counter flow plate heat exchanger, regulating rotational speed of the heat exchanger (303), and/or regulating fluid flow (503) in a coiled heat exchanger system (RAC). By the above adjustment, the carbon dioxide refrigerant cycle efficiency is maximized.

Inventors

  • Duchamp Nick Stamenkovic
  • URBAN KRONSTROM

Assignees

  • 弗莱克集团瑞典股份公司

Dates

Publication Date
20260512
Application Date
20241003
Priority Date
20231015

Claims (20)

  1. 1. An air treatment unit (50; 100, 150, 200, 250;300, 350, 400, 450;500, 550, 600, 650) comprising: An outdoor airflow passage (21); An air supply passage (22); an exhaust passage (23); An exhaust passage (24); A heat exchange feature (52), the heat exchange feature (52) being one of: PHE (102) of cross-flow/counter-flow plate heat exchanger, Wheel heat exchanger RHE (302) or Wound-tube heat exchange system RAC (502), and A carbon dioxide (R744) refrigerant circuit (760, 700, 750), the carbon dioxide (R744) refrigerant circuit (760, 700, 750) comprising: A first coil (703) placed in: -between the exhaust channel (23) and the exhaust channel (24); A second coil (702) disposed between the heat exchange feature (52) and the air supply channel (22), and A first coil air inlet temperature sensor T (801); Wherein the carbon dioxide (R744) refrigerant circuit (760, 700, 750) is configured for heat transfer between the first coil (703) and the second coil (702), It is characterized in that the method comprises the steps of, The first coil (703) is configured for heat exchange with an air flow from the exhaust channel (23), which may be air received from inside a building (900).
  2. 2. An air treatment unit (100, 200, 300, 400, 500, 600) according to claim 1, The carbon dioxide (R744) refrigerant circuit (760) is an integrated carbon dioxide cooling and heating module (700).
  3. 3. An air treatment unit (150, 250;350, 450;550, 650) according to claim 1, The carbon dioxide (R744) refrigerant circuit (760) is a cascade integrated cooling and heating module (750) with carbon dioxide pressure optimization.
  4. 4. An air treatment unit (100, 150;300, 350;500, 550) according to any of claims 1-3, The first coil (703) is placed in: And the exhaust channel (23) and the heat exchange functional component (52).
  5. 5. The air treatment unit (100, 150, 300, 350, 500, 550) according to any of claims 1-4, configured to: receiving exhaust air through the exhaust air channel (23) and via the first coil air inlet temperature sensor T (801), To the first coil (703) and then to The heat exchange functional component (52) is characterized in that the heat exchange functional component (52) is as follows: Cross flow/counter flow plate heat exchanger PHE (102), runner heat exchanger RHE (302) or coiled tube heat exchange system RAC (502).
  6. 6. An air treatment unit (200, 250, 400, 450, 600, 650) according to any of claims 1-3, wherein: the first coil (703) is placed in: The heat exchange function (52) and the exhaust passage (24).
  7. 7. An air treatment unit (200, 250;400, 450;600, 650) for cold recovery according to any of claims 1-3, 6, characterized in that it is configured to: Receives exhaust air via an exhaust air channel (23) and sends the exhaust air to The exhaust room/building temperature sensor Ti 803 is sent to the heat exchange functional component (52), and the heat exchange functional component (52) is as follows: The cross-flow/counter-flow plate heat exchanger PHE (102), the wheel heat exchanger RHE (302), or the coiled tube heat exchange system RAC (502) is then sent to The first coil air inlet temperature sensor T (801), and And then to the first coil (703).
  8. 8. The air treatment unit (100, 150, 200, 250) according to any one of claims 1-7, wherein: the heat exchange feature (52) is a cross flow/counter flow Plate Heat Exchanger (PHE) (102).
  9. 9. The air treatment unit (300, 350, 400, 450) according to any one of claims 1-7, wherein: the heat exchange feature (52) is a wheel heat exchanger (RHE) (302).
  10. 10. The air treatment unit (500, 550, 600, 650) according to any of claims 1-7, wherein: the heat exchange function (52) is a coiled tubing heat exchange system (RAC) (502).
  11. 11. The air treatment unit (100, 150, 200, 250) according to any one of claims 8-10, further comprising a side vent valve (53) configured to: when the bypass damper (52) is open, at least a portion of the airflow is allowed to bypass the heat exchange feature (52).
  12. 12. An air treatment unit (300, 350, 400, 450) according to claim 9, Also included is a wheel heat exchanger (RHE) controlled in minutes Rotation (RPM) which can be used to adjust the efficiency of the RHE heat exchange.
  13. 13. An air treatment unit (500, 550, 600, 650) according to claim 10, wherein, Also included is a coiled tubing heat exchange system (RAC) system fluid flow control actuator for regulating the efficiency of said RAC heat exchange.
  14. 14. The air treatment unit (200; 250;400, 450;600, 650) according to any one of claims 1-13, further comprising: -the exhaust room/building temperature sensor (803) configured to receive a value of the exhaust room/building temperature sensor (803).
  15. 15. An Electronic Control Unit (ECU) (800) configured to control an Air Handling Unit (AHU) (50; 100, 150, 200, 250;300, 350, 400, 450;500, 550, 600, 650) according to any of claims 1-14, comprising: Electronic Control Unit Hardware (ECUHW) (810) for sensor data processing and optimization of AHU operation; an interface connected to the first coil air inlet temperature sensor T (801), the first coil air inlet temperature sensor T (801) configured to sense a temperature at the first coil (703) air inlet; An interface with the exhaust air flow temperature sensor Ti (803), the exhaust air flow temperature sensor Ti (803) configured to sense a temperature at the exhaust air channel (23) or a temperature inside a building or room (900); a decision function module (804) configured to decide a heat exchange efficiency control signal (806) based on the data of the first coil air inlet temperature sensor T (801) and the data of the exhaust air flow temperature sensor Ti (803) acquired as needed; Controlling the AHU heat exchanger efficiency in accordance with the heat exchange efficiency control signal (806) to maintain the air inlet temperature of the first coil (703) within an optimal target range (802) of the first coil air inlet temperature sensor T (801), and -Adjusting the efficiency of the heat exchange function (52) in accordance with the heat exchange efficiency control signal (806) to regulate: Actuator (821) for PHE bypass damper, regulator (822) for RHE speed, or Regulator (823) for RAC fluid flow.
  16. 16. The ECU (800) of claim 15, further comprising: a learning function module (805) for feedback-adjusting the regulation function in the decision function module (804) based on the regulation history.
  17. 17. The ECU (800) of any one of claims 15-16, further comprising: Sensor Toptimal target range setting module (802), and/or A system profile (812), the system profile (812) defining at least one optimal temperature target range (802).
  18. 18. The ECU (800) according to any one of claims 15-17, wherein, The ECU is configured as a software-based cloud service for interfacing with and controlling at least one Air Handling Unit (AHU) (50; 100, 150, 200, 250;300, 350, 400, 450;500, 550, 600, 650) according to claims 1-13.
  19. 19. An air treatment unit (50, 100, 150, 200, 250;300, 350, 400, 450;500, 550, 600, 650) according to any of claims 1-14, further comprising: the ECU (800) according to any one of claims 14-18, configured to: controlling the air treatment unit (50, 100, 150, 200, 250;300, 350, 400, 450;500, 550, 600, 650), and/or An AHU (50, 200, 250;400, 450;600, 650) with cold recovery is controlled to maintain the detected temperature of the first coil air inlet temperature sensor T (801) at an optimal range.
  20. 20. A method of improving the efficiency of cold recovery and system efficiency of an air handling unit, the air handling unit being an Air Handling Unit (AHU) according to any one of claims 1-14, 19, the method being performed by an Electronic Control Unit (ECU) (800) according to any one of claims 15-18, comprising the steps of: (S1000) Receiving a first coil air inlet temperature acquired by a sensor T (801); (S1200) Receiving an acquisition temperature of an exhaust room/building temperature sensor Ti (803); (S2000) Determining a regulation demand (804) to generate a heat exchange efficiency control signal (806); circulating a transcritical or subcritical refrigerant to and maintaining an optimal state, and Maintaining a first coil (703) air inlet temperature at sensor T (801) within an optimal temperature range (802) for a carbon dioxide transcritical or subcritical cycle gas cooler; (S3000) -adjusting a heat exchange efficiency control parameter using the heat exchange efficiency control signal (806) by: (S3100) regulating the rotation speed (303) of the rotary heat exchanger (302); (S3200) regulating a bypass damper for a cross-flow/counter-flow heat exchanger (102), or (S3300) regulating the fluid flow rate of the coiled heat exchange system (RAC) (502), To achieve efficient cold recovery and maximum system efficiency.

Description

Air handling unit with carbon dioxide refrigerant circuit, electronic control unit, heating ventilation air conditioning system and method Technical Field The present invention relates to an Air Handling Unit (AHU) for a Heating Ventilation Air Conditioning (HVAC) system. More particularly, the present invention relates to an air treatment unit utilizing carbon dioxide as a refrigerant with integrated cooling/heating functions, particularly for HVAC systems for buildings and vehicles. Background WO2018199835A1 discloses an air treatment system with a partial indirect heat pump and a method of reducing the drop in supply air temperature in defrost mode, which provides a cooling system for recoverable cold air of a building. Propane and butane based refrigerants are highly flammable. Thus, the use of carbon dioxide, also known as R744, is a safer option. Carbon dioxide, also known as R744, is more environmentally friendly to AHU and HVAC systems than HFC and HFO refrigerants. The HVAC system may include one or more AHU modules, each module including one or more carbon dioxide refrigerant circuits for circulating carbon dioxide for cooling and heating purposes. Similar to an outdoor-mounted air conditioning system, an AHU or HVAC system may include one or more heat exchangers/air coolers disposed outside a building to be cooled. It has been found that HVAC systems and Air Handling Units (AHUs) that use carbon dioxide perform poorly and face challenges in hot environments, especially in hot summer months. The use of carbon dioxide as the refrigerant makes the control of the cooling process more sensitive than the use of the prior art refrigerants that are less sustainable. Systems using carbon dioxide are more demanding than systems using HFC, HFO, butane or propane as refrigerants because of the lower maximum temperature required for the air cooler coils to achieve optimal cooling operation. Accordingly, there is a need to provide a better method and arrangement for a carbon dioxide based air treatment unit suitable for use in buildings in hot environments. Disclosure of Invention To increase the efficiency of an Air Handling Unit (AHU) using a carbon dioxide (R744) refrigerant circuit, which is an integrated cooling and heating module without (700) or with carbon dioxide pressure optimization (750), the present inventors have recognized that the use of an outdoor air stream to cool the air cooler of the heating module reduces the likelihood of achieving optimal transcritical and subcritical carbon dioxide refrigeration processes, especially when the outdoor temperature is high, or when the outdoor air intake to the air cooler coil is placed outdoors. The temperature fluctuations and high temperatures of the outdoor air, as well as the solar radiation and microclimate, make the control process challenging and it is difficult to achieve an optimal cooling process. The present inventors have recognized a need for a better and more stable control of cooling air flow temperature. Experiments and studies have shown that in warm or sunny days, the indoor temperatures of most air conditioned buildings and rooms rarely reach as high a temperature as the outdoor air received by the AHU. Thus, an AHU configuration may be optimized, wherein AHU50, 100 the HVAC system 650 has been commissioned and put into operation in the building 900 as a complete HVAC system 20; the indoor exhaust air flow is used as the air intake of the air cooler, namely the first coil 703, and the first coil 703 belongs to an integrated cooling and heating module which is an integrated cooling and heating module without carbon dioxide 700 or with carbon dioxide pressure optimization 750. When the AHU is installed in the building 900 or at least partially installed on the outside 900', the first coil 703 is commissioned/installed in an air flow/channel passing from the interior of the building or room to receive room temperature air, which enters the exhaust air flow 23 in the exhaust channel 23, flows past the exhaust temperature sensor 803 (if any), through the heat exchange features 102, 302, 502, and finally through the first coil 703, which acts as an air cooler, to further exchange heat with the second coil 702, the second coil 702 being configured to cool the supply air 22 entering the building 900 or room. In the noted system configurations for the AHUs 50, 200, 250, 400, 450, 600, 650, HVAC system 20 and building 900, the AHU may be further equipped with functionality to control the efficiency of the heat exchange functionality 102, 302, 502 to further control and regulate the air temperature at the first coil intake air temperature sensor T801. In addition, an optimization method for maintaining the optimal first coil intake air temperature at sensor T801 is provided. The method may be implemented in the form of electronic, hardware, mechanical and/or ECU software. The present invention includes an Air Handling Unit (AHU), an HVAC system i