Decoupled dual duct re-supply air conditioning system

Abstract

This application discloses a decoupled dual-duct air supply air conditioning system, which operates in an air-conditioned room to regulate the indoor air condition. The air-conditioned room has a desired temperature and a desired indoor-outdoor pressure difference. The decoupled dual-duct air supply air conditioning system includes: an exhaust duct for exhausting gas; a first duct for supplying first fresh air at a first temperature different from the desired temperature; a second duct for supplying second fresh air at a second temperature the same as the desired temperature; a differential pressure sensor for detecting the indoor-outdoor pressure difference; and a temperature sensor for detecting the indoor temperature. When the decoupled dual-duct air supply air conditioning system regulates the indoor condition, it includes: using the first fresh air to regulate the indoor temperature, making the indoor temperature approach the desired temperature, while simultaneously changing the indoor-outdoor pressure difference; and using the second fresh air to supplement and regulate the indoor-outdoor pressure difference. This application uses the first fresh air to regulate the indoor temperature, and the first and second fresh air together regulate the indoor-outdoor pressure difference, achieving decoupled control of the room temperature and the indoor-outdoor pressure difference.

Description

Technical Field

[0001] This application relates to the field of air conditioning system technology, and in particular to a decoupled dual-duct make-up air conditioning system. Background Technology

[0002] All-air systems used in rooms with general comfort requirements typically utilize a significant portion of the return air; consequently, the less fresh air is used, the more economical the air conditioning system is. The design of fresh air volume for air-conditioned rooms generally requires taking the maximum value among the minimum fresh air volume required for occupant hygiene, the exhaust air volume for supplemental local exhaust systems, and the requirement to maintain a slightly positive pressure (generally 5-10 Pa) in the air-conditioned room. The fresh air volume for a general comfort room is the minimum fresh air volume required for occupant hygiene. Its air handling process is as follows: Figure 1 As shown in the diagram, the fresh air handling process is as follows: outdoor fresh air (air state point W) is cooled and dehumidified by a low-temperature cold source to point D, and then reheated at the terminal before being supplied to the room as supply air state point S. Supply air state point S bears all the heat and humidity load of the room.

[0003] Laboratories, as special types of buildings, may generate hazardous gases such as toxic, harmful, or explosive gases during experiments. Due to their special function, these rooms typically need to maintain a certain negative pressure and require local exhaust ventilation to expel these gases. The exhaust air must undergo tailpipe treatment before being released and cannot be used as air conditioning return air; therefore, laboratories usually employ a direct-flow 100% fresh air system. The required fresh air volume for supplementing the local exhaust ventilation system in laboratories is usually higher than the minimum fresh air volume required for personnel hygiene.

[0004] Overall, the ventilation and air conditioning design of laboratories focuses on air balance design to supplement exhaust air volume, followed by verification of indoor thermal balance. Due to the large design ventilation volume of laboratories, the air conditioning load is enormous, and in actual engineering practice, problems such as the inability to achieve thermal balance indoors, severe indoor condensation, excessively cold indoor air, high air conditioning energy consumption, and complex system control often arise. Summary of the Invention

[0005] Therefore, it is necessary to provide a decoupled dual-duct air supply air conditioning system to address the aforementioned technical problems.

[0006] This application describes a decoupled dual-duct make-up air conditioning system that operates in an air-conditioned room to regulate the indoor air conditions. The air-conditioned room has a desired pressure difference and a desired temperature. The decoupled dual-duct make-up air conditioning system includes:

[0007] An exhaust duct is used to exhaust gases from the air-conditioned room.

[0008] The first air duct is used to deliver first fresh air at a first temperature, which is different from the expected temperature.

[0009] The second air duct is used to supply a second fresh air at a second temperature, which is the same as the expected temperature.

[0010] Differential pressure sensor, used to detect the pressure difference between indoors and outdoors;

[0011] Temperature sensor used to detect indoor temperature;

[0012] When the decoupled dual-duct make-up air conditioning system adjusts the indoor state, it includes:

[0013] Using the first fresh air, the indoor-outdoor pressure difference and the indoor temperature are simultaneously adjusted to bring the indoor temperature closer to the expected temperature.

[0014] The second fresh air is used to supplement and adjust the indoor-outdoor pressure difference, so that the indoor-outdoor pressure difference approaches the expected pressure difference.

[0015] Several alternative methods are provided below, but they are not intended as additional limitations on the overall solution above. They are merely further additions or optimizations. Provided there are no technical or logical contradictions, each alternative method can be combined individually with respect to the overall solution above, or multiple alternative methods can be combined with each other.

[0016] Optionally, when the decoupled dual-duct make-up air conditioning system adjusts the indoor state, it includes:

[0017] If, during the process of utilizing the first fresh air while simultaneously adjusting the indoor-outdoor pressure difference and the indoor temperature, the indoor-outdoor pressure difference reaches the expected pressure difference, then the supply of the first fresh air shall be stopped.

[0018] Optionally, both the first temperature and the second temperature are constant values.

[0019] Optionally, the decoupled dual-duct air supply air conditioning system acts on multiple air-conditioned rooms, and the first temperature is determined based on the air-conditioned room with the largest heat load.

[0020] Optionally, at least some of the air-conditioned rooms are equipped with reheat coils, and the first fresh air enters the air-conditioned room through the reheat coils, with each air-conditioned room independently regulating the indoor state.

[0021] The air-conditioned room has a desired humidity level, and the humidity of the second fresh air is the same as the desired humidity level.

[0022] Optionally, the air-conditioned room is equipped with a mixing box for receiving and mixing the first fresh air and the second fresh air before sending them into the air-conditioned room.

[0023] Optionally, the first temperature is lower than the second temperature, and the decoupled dual-duct make-up air conditioning system includes:

[0024] The first heat exchanger is installed in the first air duct and is used to cool and dehumidify the outdoor fresh air and convert it into the first fresh air.

[0025] The second heat exchanger is located in the second air duct and is used to cool and dehumidify the outdoor fresh air.

[0026] The third heat exchanger is arranged in the second air duct and downstream of the second heat exchanger. It is used to reheat the airflow from the second heat exchanger and convert it into the second fresh air.

[0027] Optionally, the decoupled dual-duct make-up air conditioning system includes a refrigeration unit. The low-temperature cold source of the refrigeration unit is delivered to the first heat exchanger for heat exchange, and then delivered to the second heat exchanger for heat exchange.

[0028] Optionally, the decoupled dual-duct make-up air conditioning system includes:

[0029] The first fan, located in the first air duct, is used to introduce fresh outdoor air;

[0030] The first filter is installed in the first air duct and is located between the first fan and the first heat exchanger;

[0031] The second fan, installed in the second air duct, is used to introduce fresh outdoor air;

[0032] The second filter is installed in the second air duct and is located between the second fan and the second heat exchanger.

[0033] Optionally, a fume hood is provided in the air-conditioned room. The fume hood is used to absorb the gas in the air-conditioned room and discharge it into the exhaust duct.

[0034] The air-conditioned room has a desired humidity level, and the humidity of the second fresh air is the same as the desired humidity level.

[0035] The decoupling of the dual-duct make-up air conditioning system in this application has at least the following technical effects:

[0036] This application can adjust the airflow of the first fresh air source based on the signal from the indoor temperature sensor to achieve indoor temperature control; and then adjust the airflow of the second fresh air source based on the signal from the differential pressure sensor to achieve airflow balance. In terms of control logic, the first fresh air source regulates the indoor temperature, and the first and second fresh air sources jointly regulate the indoor-outdoor pressure difference, thus achieving decoupling and simultaneous control of both indoor temperature and indoor-outdoor pressure difference.

[0037] This application optimizes the control scheme by rationally allocating the air volume of the two air ducts, reduces the energy consumption for cooling and reheating the air, avoids repeated temperature oscillations during the adjustment process, and improves the energy efficiency of the system. Attached Figure Description

[0038] Figure 1 A schematic diagram of the air handling process for an existing single-duct make-up air system;

[0039] Figure 2 A schematic diagram of the control system for the reheat method at the regulating end of an existing single-duct make-up air system (where rectangles represent air-conditioned rooms);

[0040] Figure 3 This is a schematic diagram of a decoupled dual-duct make-up air conditioning system in one embodiment of this application;

[0041] Figure 4 This is a schematic diagram of the air handling process of the decoupled dual-duct make-up air conditioning system in one embodiment of this application (where the rectangles represent air-conditioned rooms);

[0042] Figure 5 This is a control flowchart of the decoupled dual-duct make-up air conditioning system in one embodiment of this application;

[0043] Figure 6 This is a schematic diagram of a decoupled dual-duct make-up air conditioning system in one embodiment of this application;

[0044] Figure 7 This is a comparison chart of the energy consumption of the decoupled dual-duct make-up air conditioning system in one embodiment of this application and the existing single-duct system when the air volume changes.

[0045] Figure 8 This is a comparison chart of the energy consumption of the decoupled dual-duct make-up air conditioning system in one embodiment of this application and the existing single-duct system when the heat load changes. Detailed Implementation

[0046] In existing technologies, negative pressure chambers with exhaust ventilation requirements primarily address the need for indoor air balance to ensure the safety of laboratory personnel, while secondary considerations include indoor temperature balance to improve comfort.

[0047] See Figure 2 The traditional control strategy for air balance and heat balance in a single-duct centralized ventilation system is to adjust the reheat heat at the terminal. This is achieved by adjusting the reheat coil in the variable air volume terminal device through an indoor temperature sensor, thereby controlling the reheat heat of the supplied air to meet the temperature requirements.

[0048] Specifically, Figure 2 Air-conditioned rooms have a target indoor-outdoor pressure difference (referred to as target pressure difference) and a target temperature. Figure 2 The exhaust fan in the room is used to remove indoor air. At this time, the differential pressure sensor in the room detects that the indoor-outdoor pressure difference deviates from the expected value. The supply fan delivers treated fresh air into the room. When the indoor-outdoor pressure difference deviates from the expected value, the amount of fresh air introduced into the room can be adjusted by controlling the variable air volume valve to adjust the indoor-outdoor pressure difference to reach the expected value. This process meets the requirement of indoor air balance.

[0049] To further adjust the indoor temperature, the incoming fresh air needs to pass through a reheat coil. The reheat coil receives hot water for both supply and return. Since maintaining indoor air balance is prioritized, the airflow volume cannot be changed. When the temperature sensor detects a deviation from the expected indoor temperature, the fresh air temperature can be adjusted by changing the hot water supply temperature of the reheat coil, thus bringing the indoor temperature back to the expected level while keeping the airflow volume constant.

[0050] The above control strategy controls the two parameters of pressure and temperature in two different ways. The pressure parameter is controlled by adjusting the air volume through a differential pressure sensor, while the temperature parameter is controlled by controlling the reheat coil through a temperature sensor.

[0051] However, the regulation of indoor and outdoor pressure difference and indoor temperature are mutually coupled. Changes in air supply volume caused by the indoor and outdoor pressure difference will cause indoor temperature to fluctuate within a certain range, failing to effectively regulate room temperature. On the one hand, during the process of regulating indoor temperature, the exhaust air volume may change again, requiring a corresponding change in the required makeup air volume, and the temperature of the reheat coil must also be adjusted accordingly. On the other hand, indoor temperature regulation relies on the detection results of temperature sensors. After air supply, the inertia of indoor air will cause a significant delay in return air temperature feedback, preventing rapid regulation of room temperature.

[0052] In general, adjusting the reheat capacity at the terminal (changing the hot water supply temperature of the reheat coil) can achieve air balance. However, the make-up air volume obtained from air balance will also affect the indoor temperature, which in turn affects the heat balance of the reheat capacity, making it difficult to achieve air and heat balance simultaneously indoors. Because the air and heat balance is inconsistent in each room, the control of the hot water supply and return system will also be relatively complex.

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0054] It should be noted that when a component is said to be "connected" to another component, it can be directly connected to the other component or it can be connected to a component in between. When a component is said to be "set on" another component, it can be directly set on the other component or it may be set to a component in between.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0056] In this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number or order of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this application, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a system, product, or device that includes a series of units is not necessarily limited to those units that are explicitly listed, but may include other units that are not explicitly listed or that are inherent to such products or devices.

[0058] See Figure 3 and Figure 4 This application provides a decoupled dual-duct make-up air conditioning system for use in an air-conditioned room to regulate indoor air conditions. The air-conditioned room can be used, for example, in a laboratory requiring negative pressure, or in other rooms requiring positive pressure. The air-conditioned room has a desired pressure difference and a desired temperature; the desired pressure difference refers to the expected value of the pressure difference between the inside and outside of the air-conditioned room. The decoupled dual-duct make-up air conditioning system includes an exhaust duct for discharging gases from the air-conditioned room (the location of the exhaust fan in the figure is the exhaust channel). Specifically, a fume hood is installed in the air-conditioned room to absorb gases from the room. During use, the opening of the variable air volume valve can be adjusted according to the wind speed monitoring on the fume hood door to discharge indoor gases into the exhaust duct.

[0059] The decoupled dual-duct air supply air conditioning system includes a first duct, a second duct, a differential pressure sensor, and a temperature sensor. The differential pressure sensor detects the indoor-outdoor pressure difference, and the temperature sensor detects the indoor temperature. The first duct supplies fresh air at a first temperature, which is different from the expected temperature. The second duct supplies fresh air at a second temperature, which is the same as the expected temperature. Furthermore, both the first and second temperatures are constant values.

[0060] In this embodiment, the first fresh air intake can adjust the airflow and handle all the indoor heat load. The second fresh air intake can meet the indoor air balance requirements. Its air handling process is as follows: Figure 4As shown in the enthalpy-humidity diagram, S1 represents the machine dew point, and S2 represents the indoor state point (point N). The first and second fresh air sources can be obtained from outdoor fresh air (air state point W0). For example, the first fresh air is cooled and dehumidified from air state point W0 by a low-temperature cold source to point S1, and the second fresh air is cooled and dehumidified from air state point W0 to point D, and then processed by a reheat coil to the indoor state point S2 (i.e., point N). S2 can represent a second temperature that is the same as the expected indoor temperature, and S1 can represent a first temperature that is lower than the expected temperature. In the above scheme, the machine dew point S1 of the first air duct can, for example, be a processing point with a relative humidity of 90% to 95%. Specifically, the decoupled dual-duct make-up air conditioning system processes the first fresh air to state point S1 and the second fresh air to state point S2.

[0061] See Figure 5 When a decoupled dual-duct make-up air conditioning system regulates indoor conditions, it includes: using a first fresh air source to simultaneously adjust the indoor-outdoor pressure difference P and the indoor temperature T, so that the indoor temperature approaches the expected temperature. Then, it uses a second fresh air source to supplement and adjust the indoor-outdoor pressure difference, making the pressure difference approach the expected pressure difference.

[0062] This embodiment breaks down the changes in indoor temperature and indoor-outdoor pressure difference, and uses temperature sensors and pressure difference sensors to adjust the make-up air volume of the first air duct (air duct 1) and the second air duct (air duct 2) respectively, so as to achieve decoupled control of thermal balance and air balance.

[0063] Indoor variable air volume (VAV) temperature control is achieved by adjusting the VAV valve in the first air duct using an indoor temperature sensor, and air balance is achieved by adjusting the VAV valve in the second air duct using a differential pressure sensor. Since the air state point in the second air duct is the same as the indoor state point, the second temperature of the second fresh air is the same as the indoor temperature. The second fresh air does not affect the indoor temperature; it is only used to supplement and regulate the indoor-outdoor pressure difference.

[0064] Compared to traditional single-duct centralized ventilation systems that require reheating all fresh air to change the indoor temperature, this embodiment optimizes the control scheme by rationally allocating the air volume of the two ducts, reducing the energy consumption for cooling and reheating the air, avoiding repeated temperature fluctuations during the adjustment process, and improving the system's energy efficiency.

[0065] Furthermore, when the decoupled dual-duct air supply air conditioning system regulates the indoor state, it includes: if the indoor-outdoor pressure difference reaches the expected pressure difference while utilizing the first fresh air and simultaneously regulating the indoor-outdoor pressure difference and indoor temperature, then the supply of the first fresh air is stopped.

[0066] Since air-conditioned rooms prioritize indoor-outdoor pressure difference over indoor temperature, if the pressure difference has already reached the expected level by only supplying the first batch of fresh air, and the indoor temperature is not as expected, some temperature regulation capacity can be sacrificed by ceasing the supply of the first batch of fresh air and also ceasing the supply of the second batch of fresh air. It's understandable that using a first batch of fresh air with a larger temperature difference relative to the indoor temperature can reduce the required amount of makeup air for the first batch of fresh air while maintaining the same temperature regulation capacity, thus avoiding this situation.

[0067] In one embodiment, the decoupled dual-duct make-up air conditioning system operates on multiple air-conditioned rooms, such as laboratories 1-3 which are maintained under negative pressure, and the first temperature is determined based on the air-conditioned room with the highest heat load. Taking a first temperature lower than the indoor temperature as an example, the first fresh air is centrally cooled and dehumidified by chilled water at a lower temperature before being delivered to the air supply state point S1. The air supply state point S1 is determined based on the air-conditioned room with the highest heat load, i.e., the most unfavorable room.

[0068] When a decoupled dual-duct make-up air conditioning system operates on multiple air-conditioned rooms, the first and second fresh air sources can be used simultaneously in multiple rooms. Because variable air volume (VAV) control is used for both the first and second fresh air sources, there is no longer a need for terminal reheat coils to adjust the reheat volume and control the temperature, thus avoiding the need for a water system distributed throughout the entire floor. However, this may lead to inaccurate humidity control in different air-conditioned rooms. Furthermore, at least some air-conditioned rooms are equipped with reheat coils, through which the first fresh air enters the air-conditioned rooms, and each air-conditioned room independently adjusts its indoor conditions. In air-conditioned rooms equipped with reheat coils, the reheat coil is installed at the end of the duct before entering the air-conditioned room. By adjusting the temperature and humidity of the first fresh air according to the needs of each air-conditioned room, precise control of the temperature and humidity of each room can be achieved. Correspondingly, the air-conditioned rooms have the expected humidity, and the humidity of the second fresh air is the same as the expected humidity.

[0069] In one embodiment, the air-conditioned room is equipped with a mixing box, such as a plenum chamber, to receive and mix the first and second fresh air before supplying them into the air-conditioned room. Alternatively, the first and second fresh air can be supplied directly to the air-conditioned room separately, or they can be mixed in the plenum chamber before being supplied to the indoor occupant area.

[0070] In one embodiment, the first temperature is lower than the second temperature. The decoupled dual-duct make-up air conditioning system includes a first heat exchanger, a second heat exchanger, and a third heat exchanger. The first heat exchanger is located in the first duct and is used to cool and dehumidify outdoor fresh air before converting it into first fresh air. The second heat exchanger is located in the second duct and is used to cool and dehumidify outdoor fresh air. The third heat exchanger is located in the second duct and downstream of the second heat exchanger, and is used to reheat the airflow from the second heat exchanger before converting it into second fresh air. All three heat exchangers can be water-to-air heat exchangers.

[0071] Furthermore, the decoupled dual-duct make-up air conditioning system includes a refrigeration unit. The low-temperature cold source from the refrigeration unit is delivered to the first heat exchanger for heat exchange, and then to the second heat exchanger for further heat exchange. The first temperature of the first fresh air is lower than the second temperature of the second fresh air. The cold source first exchanges heat with the outdoor fresh air to generate the first fresh air. The low-temperature cold source then cools and dehumidifies the fresh air, raising its temperature to form a medium-temperature cold source. This medium-temperature cold source then exchanges heat with the outdoor fresh air again, and further heat exchange with hot water to generate the second fresh air. Thus, the same cold source generates both the first and second fresh air, achieving cascaded utilization and significant energy-saving benefits. The cold source can be provided by a vapor compression cycle chiller unit driven by a motor, a steam / hot water type lithium bromide absorption chiller unit, or a direct-fired lithium bromide absorption chiller (or warm water chiller unit), etc.

[0072] In one embodiment, the decoupled dual-duct make-up air conditioning system includes a first fan, a first filter, a second fan, and a second filter. The first fan is disposed in the first duct and is used to introduce fresh outdoor air. The first filter is disposed in the first duct and is located between the first fan and a first heat exchanger. The second fan is disposed in the second duct and is used to introduce fresh outdoor air. The second filter is disposed in the second duct and is located between the second fan and the second heat exchanger. Both the first and second filters are used to remove impurities from the air.

[0073] In one embodiment, taking the air conditioning makeup air system of a laboratory in an engineering case as an example, the design and application of a decoupled dual-duct makeup air conditioning system are analyzed. The laboratory is located in Hangzhou, Zhejiang Province, with an outdoor air condition point of 35.6℃ dry bulb temperature and 27.9℃ wet bulb temperature. The indoor condition point of the laboratory is 26℃ dry bulb temperature and 60% relative humidity. The area of ​​a single laboratory is 75m². 2 The room has a clear height of 3.0m and is equipped with four variable air volume (VAV) fume hoods with a maximum exhaust volume of 1500m³ / h. 3 / h, minimum exhaust volume 420m³ 3 With all fume hoods operating at minimum exhaust volume, the laboratory's air exchange rate requirement of 6 times / hour can be met. The maximum makeup air volume is set at 5000 m³ / h. 3 / h. The design cooling load for a single laboratory is 4.89kW, and the wet load is 0.31g / s.

[0074] Based on the enthalpy-humidity diagram of the fresh air system, the supply air state point S of the single-duct system under design conditions is (23.6℃, ​​68.4%). The dew point S1 (i.e., supply air point) of duct one of the dual-duct system is (18.6℃, 90%), and the supply air point S2 of duct two is (26℃, 90%).

[0075] Based on the same engineering case, this paper analyzes the energy consumption comparison of single and dual duct systems under changes in air volume and heat load. The analysis results are as follows: Figures 7-8 As shown. Figure 7 As shown, the energy-saving advantage of the dual-duct system is obvious when the heat load is high, especially when the air volume in the second duct of the dual-duct system is not zero (i.e., the fresh air volume is greater than 1570m³). 3 At a fresh air volume of 5000 m³ / h, the energy consumption of a dual-duct system is consistently lower than that of a single-duct system. This is mainly because the dual-duct system handles the air conditioning air and the makeup air separately, thus saving reheat energy. 3 At a rate of / h, the dual-duct system saves energy by 3.52% and 5.24% at maximum and minimum heat loads, respectively. As the fresh air volume decreases, when the fresh air volume is 40%, the dual-duct system saves energy by 1.79% and 5.41%, respectively.

[0076] Figure 8 As shown, the energy consumption of the air handling process is less affected by fluctuations in heat load. With increasing heat load, the energy consumption of both single and dual duct systems decreases, but the decrease is small. Figure 7 , Figure 8 All studies show that fluctuations in air volume have a significant impact on energy consumption. This is because the make-up air load accounts for the majority of the room's air conditioning load in the laboratory, while the original building envelope load and personnel heat load have little impact on energy consumption changes. This is also the main difference between laboratory building air conditioning design and that of ordinary rooms. Figure 8 The dual-duct system consistently maintains its energy efficiency advantage under four airflow conditions: 100%, 60%, 31.4%, and 28%. When the airflow in duct 2 of the dual-duct system is zero (i.e., airflow less than or equal to 31.4% in the diagram) and the heat load is high, the enthalpy-humidity diagrams of the two systems show the same air handling state line, and their energy consumption is also consistent. Furthermore, the dual-duct system demonstrates better energy efficiency as the room load decreases, achieving energy savings of 5.24% to 5.76% under concentrated airflow at minimum heat load.

[0077] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this specification. When technical features of different embodiments are embodied in the same drawing, it can be regarded as the drawing also disclosing examples of combinations of the various embodiments involved.

[0078] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A decoupled dual-duct make-up air conditioning system for a laboratory, acting on an air-conditioned room to regulate indoor air conditions, wherein the air-conditioned room has a desired pressure difference and a desired temperature, characterized in that, The decoupled dual-duct make-up air conditioning system includes: An exhaust duct is used to exhaust gases from the air-conditioned room. The first air duct is used to deliver first fresh air at a first temperature, which is different from the expected temperature. The second air duct is used to supply a second fresh air at a second temperature, which is the same as the expected temperature. A temperature sensor is used to detect the indoor temperature, and the air volume of the first fresh air is adjusted according to the temperature sensor signal. A differential pressure sensor is used to detect the pressure difference between indoors and outdoors, and the air volume of the second fresh air is adjusted according to the signal from the differential pressure sensor. When the decoupled dual-duct make-up air conditioning system adjusts the indoor state, it includes: Using the first fresh air, the indoor-outdoor pressure difference and the indoor temperature are simultaneously adjusted to bring the indoor temperature closer to the expected temperature. The second fresh air is used to supplement and adjust the indoor-outdoor pressure difference, so that the indoor-outdoor pressure difference approaches the expected pressure difference; Both the first temperature and the second temperature are constant values, with the first temperature being lower than the second temperature. The decoupled dual-duct make-up air conditioning system includes: The first heat exchanger is installed in the first air duct and is used to cool and dehumidify the outdoor fresh air and convert it into the first fresh air. The second heat exchanger is located in the second air duct and is used to cool and dehumidify the outdoor fresh air. The third heat exchanger is arranged in the second air duct and downstream of the second heat exchanger. It is used to reheat the airflow from the second heat exchanger and convert it into the second fresh air.

2. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 1, characterized in that, When the decoupled dual-duct make-up air conditioning system adjusts the indoor state, it includes: If, during the process of utilizing the first fresh air while simultaneously adjusting the indoor-outdoor pressure difference and the indoor temperature, the indoor-outdoor pressure difference reaches the expected pressure difference, then the supply of the first fresh air shall be stopped.

3. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 1, characterized in that, The decoupled dual-duct air supply air conditioning system operates on multiple air-conditioned rooms, and the first temperature is determined based on the air-conditioned room with the largest heat load.

4. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 3, characterized in that, At least some of the air-conditioned rooms are equipped with reheat coils, and the first fresh air enters the air-conditioned room through the reheat coils, with each air-conditioned room independently regulating the indoor state. The air-conditioned room has a desired humidity level, and the humidity of the second fresh air is the same as the desired humidity level.

5. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 1, characterized in that, The air-conditioned room is equipped with a mixing box, which is used to receive and mix the first fresh air and the second fresh air before sending them into the air-conditioned room.

6. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 1, characterized in that, The decoupled dual-duct air supply air conditioning system includes a refrigeration unit. The low-temperature cold source of the refrigeration unit is delivered to the first heat exchanger for heat exchange, and then delivered to the second heat exchanger for heat exchange.

7. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 1, characterized in that, The decoupled dual-duct make-up air conditioning system includes: The first fan, located in the first air duct, is used to introduce fresh outdoor air; The first filter is installed in the first air duct and is located between the first fan and the first heat exchanger; The second fan, installed in the second air duct, is used to introduce fresh outdoor air; The second filter is installed in the second air duct and is located between the second fan and the second heat exchanger.

8. The decoupled dual-duct make-up air conditioning system for laboratories as described in claim 1, characterized in that, The air-conditioned room is equipped with a fume hood, which is used to absorb the gas in the air-conditioned room and discharge it into the exhaust duct. The air-conditioned room has a desired humidity level, and the humidity of the second fresh air is the same as the desired humidity level.

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