Economizer, roof unit and integral air conditioner

Abstract

The invention provides an economizer, a roof unit and an integral air conditioner. The economizer comprises a shell, a fresh air valve and a return air valve. A fresh air chamber and an air return chamber are arranged in the shell, and a fresh air valve is arranged in the fresh air chamber; the air return cavity is provided with an air return channel and an air exhaust channel, an air return valve is arranged in the air return channel, a first air exhaust opening and a second air exhaust opening are formed in the shell, an air outlet of the air exhaust channel is communicated with the first air exhaust opening, an air outlet of the air return channel is communicated with the second air exhaust opening, and the pressure drop in the air exhaust channel is smaller than that in the air return channel. In the running process of the unit, no matter in a full air return mode or when fresh air needs to be conveyed, the air exhaust channel can participate in adjustment of indoor pressure, and the indoor positive pressure is always controlled within a reasonable range.

Description

Technical Field

[0001] The present invention belongs to the technical field of rooftop units, and in particular relates to an economizer, a rooftop unit and an integrated air conditioner. Background Art

[0002] An economizer is an arrangement of ducts, dampers, and an automatic control system that work together to enable the refrigeration system to supply outdoor air in mild or cold weather, thereby reducing or eliminating the need for mechanical cooling. A unit equipped with an air-side economizer operates just like a conventional unit: the fresh air damper is closed and the return air damper is open. At this point, the unit operates in full return air mode. Because there is negative pressure ahead of the fan, the indoor pressure on both sides of the release damper is lower than the outdoor pressure, forcing the release damper to close under atmospheric pressure. As the outdoor temperature or outdoor enthalpy decreases, the fresh air damper opens wider and the return air damper opens narrower. At the same time, the greater the fresh air volume, the higher the indoor positive pressure. When the indoor positive pressure exceeds the outdoor pressure, the release damper opens. The magnitude of indoor positive pressure is not only related to the fresh air volume but also to the length of the return air duct. The longer the return air duct, the greater the negative pressure at the fan inlet. This increases the pressure differential between the inside and outside of the release damper, making it more difficult for indoor air to escape. This creates excessive positive indoor pressure. Excessive positive indoor pressure can make it difficult to open doors and windows, so it's important to control the indoor positive pressure within a reasonable range. The existing solution to excessive indoor positive pressure caused by long return air ducts is to add exhaust fans. While this approach effectively addresses excessive indoor positive pressure, it also increases noise, energy consumption, and the number of failure points. Summary of the Invention

[0003] The present invention provides an economizer, a rooftop unit and an integrated air conditioner, which can solve the technical problems of excessive indoor positive pressure, increased noise and increased energy consumption by adding an exhaust fan in the prior art.

[0004] The present invention provides an economizer, which includes a housing, a fresh air valve and a return air valve;

[0005] A fresh air chamber and a return air chamber are provided in the housing, and the fresh air chamber is provided with the fresh air valve; the return air chamber has a return air channel and an exhaust air channel that are isolated from each other, and the return air valve is provided in the return air channel, the fresh air valve is used to adjust the intake volume of fresh air, and the return air valve is used to adjust the supply volume of return air to the indoor side;

[0006] The shell is provided with a first exhaust port and a second exhaust port, the air outlet of the exhaust channel is connected to the first exhaust port, and the air inlet of the exhaust channel is connected to the indoor side; the air outlet of the return air channel is connected to the second exhaust port, and the air inlet of the return air channel is connected to the indoor side, a second exhaust valve is provided at the second exhaust port, and the pressure drop in the exhaust channel is smaller than the pressure drop in the return air channel.

[0007] In some embodiments, a return air duct is provided at the air inlet of the return air channel, and the end of the return air duct facing away from the return air channel is connected to the indoor side, a return air passage is formed between the return air duct and the return air channel, and the pressure drop in the exhaust channel is smaller than the pressure drop in the return air passage.

[0008] In some embodiments, a first exhaust valve is provided at the first exhaust port, and both the first exhaust valve and the second exhaust valve are used to adjust the air supply volume of the return air discharged to the outdoor side.

[0009] In some embodiments, the first exhaust valve and the second exhaust valve are both pressure relief valves, the return air valve is arranged on the exhaust path of the return air duct, and when the return air pressure at the return air valve is less than the ambient pressure outside the room, the first exhaust valve opens; when the return air pressure at the return air valve is greater than the ambient pressure outside the room, both the first exhaust valve and the second exhaust valve open.

[0010] In some embodiments, a driving device is further included, and the fresh air valve and the return air valve are drivingly connected to the driving device, and the driving device is used to control the opening and closing degree of the fresh air valve and the exhaust air valve.

[0011] In some embodiments, the shell is further provided with a mixing chamber, and the air supply paths of the fresh air chamber and the return air duct respectively extend to the mixing chamber.

[0012] In some embodiments, an evaporator and a blower are further provided in the shell, the evaporator is provided on the air outlet path of the mixing chamber, the blower is provided on the side of the evaporator away from the mixing chamber, an air outlet is provided on the shell, and the air outlet of the blower faces the air outlet.

[0013] A mixed air temperature sensor is provided in the mixing chamber, or an outlet air temperature sensor is provided at the air supply port.

[0014] A rooftop unit includes an economizer, wherein the economizer is the above-mentioned economizer.

[0015] An integrated air-conditioning unit includes an economizer, wherein the economizer is the economizer described above.

[0016] The economizer, rooftop unit, and integrated air conditioner provided by the present invention have the following beneficial effects:

[0017] The pressure drop in the exhaust duct of the present invention is smaller than the pressure drop in the return air duct, which makes it more likely that the return air will be discharged outdoors through the exhaust duct when the indoor positive pressure increases. When the opening of the fresh air valve increases and the opening of the return air valve decreases, the fresh air volume increases, causing the indoor positive pressure to increase. Due to the low pressure drop characteristic of the exhaust duct, the indoor return air can smoothly flow into the exhaust duct and be discharged outdoors under a small pressure difference, thereby releasing excess indoor air in a timely manner and avoiding excessive indoor positive pressure. During the operation of the unit, whether in full return air mode or when fresh air needs to be delivered, the exhaust duct can participate in regulating the indoor pressure. In full return air mode, the return air mainly flows in the return air duct and is returned to the indoor side. When fresh air is needed and the opening of the fresh air valve increases, as the indoor positive pressure increases, the exhaust duct begins to function, allowing part of the return air to be discharged from the first exhaust port, thereby balancing the indoor pressure and preventing the building doors and windows from being difficult to open due to excessive indoor positive pressure. The indoor positive pressure is always controlled within a reasonable range to ensure the normal use of the building and the comfort of the people. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0019] Figure 1 It is a schematic diagram of a conventional economizer;

[0020] Figure 2 is a schematic diagram of an economizer according to an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of an economizer when the first exhaust valve is open according to an embodiment of the present invention;

[0022] Figure 4 Schematic diagram of an economizer when the first exhaust valve and the second exhaust valve are open according to an embodiment of the present invention;

[0023] Figures: 1-shell; 11-first exhaust outlet; 12-second exhaust outlet; 101-fresh air chamber; 102-return air duct; 121-return air duct; 103-exhaust duct; 104-mixing chamber; 2-fresh air valve; 3-return air valve; 41-first exhaust valve; 42-second exhaust valve; 5-evaporator; 6-blower. DETAILED DESCRIPTION

[0024] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0026] For ease of description, spatially relative terms such as "on," "above," "on the upper surface of," and "upper" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in a drawing is inverted, a device described as "above" or "on top of" the other devices or features would then be positioned "below" or "beneath" the other devices or features.

[0027] See also Figure 2As shown, according to an embodiment of the present invention, an economizer is provided, comprising a housing 1, a fresh air valve 2 and a return air valve 3; a fresh air chamber 101 and a return air chamber are provided in the housing 1, and a fresh air valve 2 is provided in the fresh air chamber 101; the return air chamber has a return air channel 102 and an exhaust air channel 103 that are isolated and arranged, and a return air valve 3 is provided in the return air channel 102, the fresh air valve 2 is used to adjust the amount of fresh air inlet, and the return air valve 3 is used to adjust the amount of return air sent to the indoor side; a first exhaust port 11 and a second exhaust port 11 are provided on the housing 1. The air outlet 12 and the air outlet of the exhaust channel 103 are connected to the first exhaust channel 11, and the air inlet of the exhaust channel 103 is connected to the indoor side; the air outlet of the return air channel 102 is connected to the second exhaust channel 12, and the air inlet of the return air channel 102 is connected to the indoor side. A second exhaust valve 42 is provided at the second exhaust channel 12, and the pressure drop in the exhaust channel 103 is less than the pressure drop in the return air channel 102. Pressure drop refers to the change in energy. The pressure drop caused by energy loss when the fluid flows in the pipe is caused. The size of the pressure drop affects the flow of return air.

[0028] Specifically, when the unit operates in full return air mode, the fresh air valve 2 is closed and the return air valve 3 is open. At this time, the air pressure on the indoor side is lower than the air pressure on the outdoor side, and the return air flows in the return air duct 102. The second exhaust valve 42 is also closed, and the return air is not discharged to the outdoor side. The return air is delivered to the indoor side after cooling or heating; when fresh air needs to be delivered to the indoor side, the fresh air valve 2 is opened, the opening of the fresh air valve 2 increases, and the opening of the return air valve 3 decreases, and the fresh air on the outdoor side enters the fresh air chamber 101. In order to avoid the increasing environmental pressure on the indoor side, the return air on the indoor side can still flow into the return air duct 102, so that the fresh air and return air air flows are mixed, and the mixed air is sent to the indoor side after heat exchange. As the outdoor ambient temperature or outdoor enthalpy value decreases, the opening of the fresh air valve 2 gradually increases, and the opening of the return air valve 3 gradually decreases. At the same time, the larger the fresh air volume, the higher the indoor positive pressure. At this time, since the indoor ambient pressure is still lower than the outdoor ambient pressure, the return air in the return air duct 102 still needs to be discharged from the return air valve 3 and mixed with the fresh air. The second exhaust valve 42 is still closed, and the pressure drop in the exhaust duct 103 is less than the pressure drop in the return air duct 102, so that the return air in the exhaust duct 103 is discharged from the first exhaust port 11. When the opening of the fresh air valve 2 is opened to the maximum and the return air valve 3 is completely closed, the indoor ambient positive pressure reaches the maximum value. The second exhaust valve 42 opens, and the return air in the exhaust duct 103 and the return air duct 102 are both discharged from the indoor side to the outdoor side, avoiding excessive indoor ambient positive pressure and keeping the indoor positive pressure within a reasonable range.

[0029] In this embodiment, the pressure drop within the exhaust duct 103 is less than the pressure drop within the return air duct 102. This makes it more likely that when the indoor positive pressure increases, the return air will be discharged outdoors through the exhaust duct 103. When the opening of the fresh air valve 2 increases and the opening of the return air valve 3 decreases, the fresh air volume increases, causing the indoor positive pressure to increase. Due to the low pressure drop characteristic of the exhaust duct 103, the indoor return air can smoothly flow into the exhaust duct 103 and be discharged outdoors under a small pressure difference, thus releasing excess indoor air in a timely manner and avoiding excessive indoor positive pressure. During the operation of the unit, whether in full return air mode or when fresh air needs to be delivered, the exhaust duct 103 can participate in the regulation of indoor pressure. In full return air mode, the return air mainly flows in the return air duct 102 and is returned to the indoor side; when fresh air is needed and the opening of the fresh air valve 2 increases, as the indoor positive pressure increases, the exhaust duct 103 begins to play a role, allowing part of the return air to be discharged from the first exhaust port 11, so as to balance the indoor pressure and prevent the building doors and windows from being difficult to open due to excessive indoor positive pressure. The indoor positive pressure is always controlled within a reasonable range to ensure the normal use of the building and the comfort of the personnel.

[0030] In this embodiment, referring to Figure 1As shown, although the setting of the return air duct 102 is a conventional setting, the setting of the return air duct 102 and the exhaust air duct 103 plays a synergistic role. On the one hand, when fresh air needs to be transported to the indoor side, the fresh air valve 2 is opened and the opening gradually increases, and the opening of the return air valve 3 gradually decreases. The entry of fresh air increases the indoor positive pressure. As the indoor positive pressure increases, when the ambient pressure on the indoor side reaches a certain level, since the pressure drop in the exhaust air duct 103 is less than the pressure drop in the return air duct 102, the indoor return air is more likely to be discharged to the outside through the exhaust air duct 103, thereby releasing excess indoor air and avoiding excessive indoor positive pressure. At the same time, the return air duct 102 still bears part of the return air transportation task, and cooperates with the exhaust air duct 103 to jointly maintain the balance of indoor pressure, so that the indoor positive pressure is always controlled within a reasonable range. On the other hand, the return air in the return air duct 102 is mainly used for cooling or heating and then transported to the indoor side again, so as to realize the recycling of indoor air and improve energy utilization efficiency. The return air in the return air duct 102 is mainly used for cooling or heating and then transported to the indoor side again, so as to realize the recycling of indoor air and improve energy utilization efficiency. In addition, the setting of the two channels enables the unit to automatically adjust the opening of the fresh air valve 2 and the return air valve 3 according to the changes in the outdoor temperature or the outdoor enthalpy value, so as to flexibly change the mixing ratio of the fresh air and the return air to meet the indoor air conditioning needs under different working conditions. The return air duct 102 and the exhaust air duct 103 are independent of each other and work in coordination, ensuring that the unit can operate stably in both the full return air mode and the mixed air mode, avoiding the normal operation of the unit affected by excessive indoor positive pressure, improving the stability and reliability of the system, and reducing the risk of equipment failure. Compared with the traditional method of adding exhaust fans, this embodiment can effectively solve the problem of excessive indoor positive pressure caused by the long return air duct by setting the return air duct 102 and the exhaust air duct 103 without adding additional exhaust fans, thereby avoiding the problems of increased noise, increased energy consumption and increased failure points caused by adding exhaust fans, and reducing the operating cost and maintenance difficulty of the system.

[0031] It is worth noting that, in this embodiment, since the return air duct 102 needs to mix the return air with the fresh air and then send it into the indoor side, and also needs to discharge the return air to the outdoor side after the positive pressure on the indoor side increases, in order to prevent the outdoor air from being sucked into the return air duct 102, this embodiment is provided with a second exhaust valve 42 at the second exhaust port 12. During the operation of the exhaust duct 103, the return air in the exhaust duct 103 does not need to be discharged into the indoor side, but only needs to be discharged into the outdoor side. Therefore, an exhaust valve can be provided at the first exhaust port 11, or an exhaust valve can be not provided.

[0032] See also Figures 2 to 4As shown, a return air duct 121 is provided at the air inlet of the return air channel 102. The end of the return air duct 121 facing away from the return air channel 102 is connected to the indoor side. A return air passage is formed between the return air duct 121 and the return air channel 102. The pressure drop in the exhaust channel 103 is less than the pressure drop in the return air passage.

[0033] For details, see Figure 1 As shown, the return air duct 102 is usually connected to a long return air duct 121, forming a return air passage with a long flow path, which delivers the return air from the indoor side into the return air duct 102. The magnitude of the positive pressure of the indoor environment is not only related to the amount of fresh air, but also to the length of the pipe connected to the return air duct 102. For example, without considering the influence of the diameter of the return air duct 121, the length of the exhaust duct 103 is much smaller than that of the return air duct 121, so that the pressure drop in the exhaust duct 103 is smaller than the pressure drop in the return air duct. In order to solve the influence of the pipe pressure drop on the discharge of return air, In this embodiment, two isolated channels are provided for the discharge of return air, and an exhaust channel 103 is provided separately. For example, the pipe length of the exhaust channel 103 can be limited to be smaller than the pipe length of the return air duct 121, that is, the overall effect of the pipe pressure drop on the discharge of return air can be reduced. When there is a certain pressure difference between indoors and outdoors, the return air can be discharged through the exhaust channel 103. When the ambient pressure on the indoor side gradually increases, the return air can also be discharged to the outdoor side after flowing into the return air chamber from the return air duct 121. At this time, both the exhaust channel 103 and the return air channel 102 have return air discharge.

[0034] In this embodiment, the return air duct 102 is connected to a longer return air pipe 121, which is primarily responsible for transporting indoor return air back to the unit for cooling or heating before being transported back indoors, achieving indoor air recycling. The exhaust duct 103, on the other hand, is used to discharge some return air when the indoor positive pressure is high, allowing the fresh air and return air to properly mix and exchange heat within the unit, thereby improving air treatment efficiency. By considering the influence of pipe length, the exhaust duct 103 can assist in regulating the discharge of return air without affecting the primary function of the return air duct 102. When fresh air enters the unit and mixes with the return air, the mixing ratio can be more precisely controlled, allowing the mixed air to better exchange heat, improving the heat exchange efficiency of the entire system, and ensuring that indoor air parameters meet comfort requirements. Compared to traditional methods such as adding exhaust fans, this method of controlling return air discharge by limiting pipe length avoids the problems of increased noise, increased energy consumption, and increased failure points caused by adding additional equipment, thereby improving system reliability and stability and reducing maintenance costs and the risk of equipment failure.

[0035] As a specific embodiment, when the unit is used in a rooftop unit, the return air duct 121 in each room needs to be connected to the unit. The route layout determines that the length of the return air duct 121 cannot be shortened. Therefore, the exhaust duct 103 provided in this embodiment addresses this situation. In the room where the unit is installed, the air inlet of the exhaust duct 103 is connected to a room. Since air also flows between rooms, the connection between the exhaust duct 103 and a room can reduce the positive pressure inside the room to a certain extent. The exhaust duct 103 is provided to provide a relatively low-resistance exhaust path to discharge some return air when the positive pressure in the room is high, thereby reducing the positive pressure inside the room. In the application scenario of a rooftop unit, even if the return air duct 121 in each room is connected to the unit and its length cannot be shortened, an air inlet of the exhaust duct 103 can be set in each room, and the pipe length of the exhaust duct 103 can be designed to be shorter than the return air duct 121. This can make the pressure drop in the exhaust duct 103 smaller than the pressure drop in the return air duct 102. In this way, when the indoor positive pressure rises to a certain level, the return air will be discharged from the exhaust duct 103 first, thereby reducing the positive pressure on the indoor side. In this embodiment, the pipe length and diameter of the exhaust duct 103 and the return air duct 102 can also be calculated to ensure that the pressure drop in the exhaust duct 103 is indeed smaller than that in the return air passage. At the same time, the aerodynamic characteristics of the entire system must be considered to avoid excessive local resistance caused by unreasonable pipe design, which may affect the normal operation of the entire system.

[0036] In a specific embodiment, exhaust duct 103 is a pipe segment structure. This pipe structure, when installed in the return air chamber, forms exhaust duct 103, while the remaining portion of the return air chamber forms return air duct 102. Exhaust duct 103 and return air duct 102 are isolated channels. To better facilitate the discharge of return air, exhaust duct 103 is a curved pipe structure at a certain angle. The specific structure can be flexibly adjusted based on exhaust requirements and pressure drop considerations.

[0037] As a specific implementation method, the fresh air chamber 101 and the return air chamber in this embodiment are also isolated from each other, that is, the fresh air chamber 101 and the exhaust channel 103 and the return air channel 102 are also isolated from each other. The fresh air valve 2 can be set at the entrance of the fresh air chamber 101 or at the outlet of the fresh air chamber 101. The setting position of the fresh air valve 2 does not affect the fresh air supply effect.

[0038] See also Figures 2 to 4 As shown, a first exhaust valve 41 is provided at the first exhaust outlet 11, and a second exhaust valve 42 is provided at the second exhaust outlet 12. The first exhaust valve 41 and the second exhaust valve 42 are both used to adjust the air supply volume of the return air discharged to the outdoor side. In this embodiment, it is preferred that exhaust valves are provided at each of the two exhaust outlets to further prevent outdoor air from being sucked into the indoor side.

[0039] Specifically, as the outdoor ambient temperature or the outdoor enthalpy value decreases, the opening of the fresh air valve 2 gradually increases, and the opening of the return air valve 3 gradually decreases. At the same time, the larger the fresh air volume, the higher the indoor positive pressure. At this time, since the indoor ambient pressure is still lower than the outdoor ambient pressure, the return air in the return air duct 102 still needs to be discharged from the return air valve 3 and mixed with the fresh air, and the pressure drop in the exhaust duct 103 is less than the pressure drop in the return air duct 102. For the first air valve, the pressure of the first exhaust valve 41 on the side of the exhaust duct 103 is greater than the outdoor ambient pressure. The first exhaust valve 41 is opened to allow the return air in the exhaust duct 103 to be discharged from the first exhaust port 11. When the fresh air valve 2 is opened to the maximum and the return air valve 3 is completely closed, the positive pressure of the indoor environment reaches the maximum value. The return air pressure of the first exhaust valve 41 and the second exhaust valve 42 on one side of the channel is greater than the ambient pressure on the outdoor side. Both exhaust valves are opened, and the return air in the exhaust channel 103 and the return air channel 102 is discharged from the indoor side to the outdoor side, avoiding excessive positive pressure in the indoor environment and keeping the indoor positive pressure within a reasonable range.

[0040] In this embodiment, the maximum static pressure of a conventional air side economizer without an exhaust fan can be reduced by adding one more stage (two stages in total) of exhaust valves without adding an exhaust fan. As the outdoor ambient temperature or the outdoor enthalpy value changes, the openings of the fresh air valve 2 and the return air valve 3 are continuously adjusted. The first exhaust valve 41 and the second exhaust valve 42 can respectively adjust the air supply volume of the return air discharged from the exhaust channel 103 and the return air channel 102 according to the change of the indoor positive pressure and the operating requirements of the system, so that the unit can accurately control the discharge of the return air under different working conditions to ensure that the indoor positive pressure is maintained within a reasonable range. The two exhaust valves each control a different exhaust path and can operate independently according to the pressure conditions in their respective channels. For example, when the indoor positive pressure rises to a certain level, the first exhaust valve 41 will open because the pressure on one side of the exhaust channel 103 is greater than the outdoor ambient pressure, allowing the return air in the exhaust channel 103 to be discharged; while the second exhaust valve 42 will only open when the return air pressure in the return air channel 102 is large enough, which can more flexibly adapt to different pressure conditions and exhaust requirements. The first exhaust valve 41 and the second exhaust valve 42 can remain closed when exhaust is not required, effectively isolating the pressure difference between indoor and outdoor, preventing outdoor air from flowing back into the room through the exhaust port, ensuring the stability of indoor air quality and pressure, and at the same time, preventing the return air from flowing back in the channel when it is not required to be discharged, disrupting the normal air flow order.

[0041] In this embodiment, as the opening of the fresh air valve 2 gradually increases, when the indoor positive pressure rises to a certain level, the first exhaust valve 41 opens first, and the exhaust duct 103 begins to discharge return air, initially alleviating the indoor positive pressure. As the fresh air valve 2 continues to open wider and the return air valve 3 gradually closes, the pressure in the return air duct 102 gradually increases. At this time, the second exhaust valve 42 also opens, causing the return air in the return air duct 102 to also begin to be discharged. Together with the exhaust duct 103, this further reduces the indoor positive pressure, prevents excessive indoor positive pressure, and achieves phased exhaust. When the fresh air valve 2 is fully opened and the return air valve 3 is completely closed, the indoor positive pressure reaches its maximum value. At this time, both exhaust valves are fully opened, and the exhaust duct 103 and the return air duct 102 discharge return air simultaneously, exhausting the indoor air to the maximum extent possible, ensuring that the indoor positive pressure does not exceed a reasonable range, protecting the normal use of the building structure and doors and windows, and also ensuring the comfort of indoor occupants.

[0042] As a specific implementation, the economizer in this embodiment refers to a channel formed by the housing 1 and various air valves. These function together to enable the refrigeration system to supply outdoor air in mild or cold weather, thereby reducing or eliminating the need for mechanical cooling. There are four conditions for activating the air-side economizer: 1) Single temperature point judgment: a set outdoor temperature point is set when the outdoor ambient temperature is lower than the set value; 2) Temperature difference judgment: when the outdoor air temperature is lower than the indoor temperature; 3) Single enthalpy point judgment: a set outdoor enthalpy value is set when the outdoor enthalpy value is lower than the set value; 3) Enthalpy difference judgment: when the outdoor air enthalpy value is lower than the indoor air enthalpy value. This embodiment primarily adjusts the opening of the fresh air valve 2 and the return air valve 3 based on changes in indoor and outdoor temperature and enthalpy value.

[0043] See also Figures 2 to 4 As shown, the first exhaust valve 41 and the second exhaust valve 42 are both pressure relief valves, the return air valve 3 is arranged on the exhaust path of the return air duct 102, and when the return air pressure at the return air valve 3 is less than the ambient pressure outside the room, the first exhaust valve 41 opens; when the return air pressure at the return air valve 3 is greater than the ambient pressure outside the room, the first exhaust valve 41 and the second exhaust valve 42 are both opened.

[0044] In this embodiment, the first and second exhaust valves 41 and 42 act as pressure relief valves, automatically opening and closing based on the relative pressure between the return air pressure at the return air valve 3 and the outdoor ambient pressure. When the return air pressure is low, only the first exhaust valve 41 opens, providing a preliminary exhaust path. When the return air pressure rises above the outdoor ambient pressure, both exhaust valves open, ensuring timely exhaust of excess return air under varying pressure conditions and maintaining stable indoor pressure. When the return air pressure does not reach the conditions for opening the second exhaust valve 42, the second exhaust valve 42 remains closed, reducing unnecessary exhaust, avoiding energy waste caused by excessive exhaust, and ensuring efficient indoor air circulation. Automatic control of the exhaust valves rationally distributes the return air flow path. When the return air pressure is low, some return air is discharged primarily through the exhaust duct 103 where the first exhaust valve 41 is located. When the return air pressure is high, both exhaust ducts 103 operate together, allowing the return air to be discharged outdoors in a more orderly manner, avoiding airflow turbulence and improving air flow efficiency. Compared to traditional fixed exhaust methods, the automatic control function of the pressure relief valve reduces the risk of equipment failure due to abnormal pressure. It can flexibly adjust according to actual pressure conditions, avoiding damage to equipment such as fans and dampers caused by poor or excessive exhaust, extending equipment life and reducing maintenance costs.

[0045] See also Figures 2 to 4 As shown, a driving device is also included, and the fresh air valve 2 and the return air valve 3 are driven and connected to the driving device, and the driving device is used to control the opening and closing degree of the fresh air valve 2 and the exhaust air valve.

[0046] In this embodiment, the opening degree of the fresh air valve 2 is opposite to that of the exhaust air valve, that is, the opening degree of the fresh air valve 2 increases and the opening degree of the return air valve 3 decreases. The opening degree of the two air valves is adjusted by the forward and reverse rotation of the driving device.

[0047] Specifically, the driving device adjusts the opening and closing degree of the fresh air valve 2 and the return air valve 3 by forward and reverse rotation. By setting the driving device, the fresh air valve 2 and the return air valve 3 are linked and reversely controlled. This control method has been widely used in existing ventilation and air-conditioning systems and will not be described in detail here. Since the opening and closing degree of the fresh air valve 2 and the return air valve 3 are controlled by the same driving device, and the opening degree is opposite, it can ensure that the adjustment action between the two has good synchronization and coordination, thereby improving the adjustment accuracy of the system. At the same time, it avoids the adjustment lag problem caused by the response time difference between multiple driving devices, so that the system can respond more quickly to changes in indoor positive pressure and outdoor environmental parameters, adjust the fresh return air ratio in time, and maintain the stability of indoor air parameters. See in conjunction with Figures 2 to 4As shown, the shell 1 is also provided with a mixing chamber 104, and the air supply paths of the fresh air chamber 101 and the return air duct 102 extend to the mixing chamber 104 respectively. The mixing chamber 104 is also a chamber formed between the windward surface of the evaporator 5, the fresh air valve 2 and the return air valve 3. Its specific volume size and structural form can be flexibly adjusted.

[0048] Specifically, when the unit operates in full return air mode, the fresh air valve 2 is closed and the return air valve 3 is open. At this time, the air pressure on the indoor side is lower than the air pressure on the outdoor side. The return air flows in the return air duct 102, and the return air is not discharged to the outdoor side. The return air first flows through the mixing chamber 104 and is then delivered to the indoor side after cooling or heating; when fresh air needs to be delivered to the indoor side, the fresh air valve 2 is opened, the opening of the fresh air valve 2 increases, and the opening of the return air valve 3 decreases. The fresh air on the outdoor side enters the fresh air chamber 101, and the return air on the indoor side can still flow into the return air duct 102, so that the fresh air and return air air flows are mixed in the mixing chamber 104, and the mixed air is sent to the indoor side after heat exchange. As the outdoor ambient temperature or outdoor enthalpy value decreases, the opening of the fresh air valve 2 gradually increases, and the opening of the return air valve 3 gradually decreases. At the same time, the larger the fresh air volume, the higher the indoor positive pressure. At this time, since the indoor ambient pressure is still lower than the outdoor ambient pressure, the return air in the return air duct 102 still needs to be discharged from the return air valve 3 and mixed with the fresh air in the mixing chamber 104. The pressure drop in the exhaust duct 103 is less than the pressure drop in the return air duct 102, so that the return air in the exhaust duct 103 is discharged from the first exhaust port 11. When the opening of the fresh air valve 2 is opened to the maximum, the return air valve 3 is completely closed, and only the fresh air flows through the mixing chamber 104. At this time, the indoor ambient positive pressure reaches the maximum value, and the return air in the exhaust duct 103 and the return air duct 102 are both discharged from the indoor side to the outdoor side.

[0049] In this embodiment, the mixing chamber 104 provides a mixing space for the fresh air and the return air, so that the two airflows can be fully and evenly mixed together. This can avoid the situation where the fresh air and the return air have excessively large local temperature or humidity differences when entering the room, ensure that the parameters of the air delivered to the room are more uniform and stable, and improve the thermal comfort of the room. The mixed air is subjected to heat exchange treatment (cooling or heating) in the mixing chamber 104, which can more efficiently utilize the heat exchange capacity of the unit compared to treating the fresh air or the return air separately. Since the flow rate of the mixed air is relatively stable and the parameters are relatively uniform, it helps to improve the working efficiency of the heat exchanger and make the air reach the required temperature and humidity conditions. The existence of the mixing chamber 104 provides a relatively stable mixing and transition space for the fresh air and the return air before entering the room, reduces the direct impact and turbulence of the airflow in the room, makes the airflow organization in the room more reasonable, and is conducive to forming a good air distribution effect, improving the uniformity and comfort of the indoor air.

[0050] As a specific embodiment, by controlling the openings of the fresh air valve 2 and the return air valve 3, the mixing ratio of fresh air and return air can be specifically adjusted in the mixing chamber 104 according to changes in outdoor environmental conditions and indoor air conditioning load. For example, when the outdoor temperature is low, the fresh air ratio is increased and the return air ratio is reduced to fully utilize the cooling capacity of the outdoor fresh air; when the outdoor temperature is high, the fresh air ratio is appropriately reduced and the return air ratio is increased to reduce the cooling load. This allows the mixing ratio of fresh air and return air to be precisely adjusted based on factors such as indoor occupancy density and air quality to ensure indoor air quality. When there are many people or the indoor air quality is poor, the fresh air volume is increased to improve indoor air quality; when there are fewer people or the indoor air quality is good, the fresh air volume is appropriately reduced to achieve energy-saving operation.

[0051] See also Figures 2 to 4 As shown, an evaporator 5 and a blower 6 are also provided in the shell 1. The evaporator 5 and the blower 6 are arranged in the shell 1. The evaporator 5 is arranged on the air outlet path of the mixing chamber 104. The blower 6 is arranged on the side of the evaporator 5 away from the mixing chamber 104. An air outlet is provided on the shell 1, and the air outlet of the blower 6 faces the air outlet.

[0052] In this embodiment, referring to Figure 1 , the conventional setting is usually to set up another exhaust fan in the return air chamber to discharge the return air from the indoor side to the outdoor side, but in this embodiment, only one supply fan 6 is set up for supplying air. In the conventional setting, an exhaust fan is set up in the return air chamber to discharge the return air to the outside, but in this embodiment, only one supply fan 6 is set up for supplying air, which simplifies the equipment configuration, reduces the number of fans, and reduces the equipment procurement cost and installation complexity. In addition, the space occupied by the fan is reduced, making the unit structure more compact and convenient for installation and layout in a limited space. At the same time, since only one supply fan 6 is used, compared with the case of using multiple fans, the energy consumption of the system is reduced, the energy utilization efficiency is improved, and the operating cost is reduced.

[0053] As a specific implementation method, the return air valve 3 is arranged on the exhaust path of the return air duct 102, that is, when the second exhaust port 12 does not need to exhaust air and the return air valve 3 is opened, the return air in the return air duct 102 flows through the return air valve 3 and is then sent to the windward surface of the evaporator 5. When the pressure at the return air valve 3 is greater than the ambient pressure on the outdoor side, the second exhaust valve 42 is opened, the return air valve 3 is closed, and the return air duct 102 discharges the return air to the outdoor side.

[0054] See also Figure 2As shown, a mixed air temperature sensor is provided in the mixing chamber 104, or an outlet air temperature sensor is provided at the air outlet. Parameters such as outdoor temperature and indoor positive pressure can be monitored by sensors, and these signals can be fed back to the control system. For example, a mixed air temperature sensor is placed in the mixing chamber 104, or an outlet air temperature sensor is placed at the air outlet. The openings of the fresh air valve 2 and the return air valve 3 are controlled according to the mixed air temperature value and the outlet air temperature value. The control system calculates the required openings of the fresh air valve 2 and the return air valve 3 according to the preset control logic and algorithm, and sends corresponding forward and reverse control signals to the drive device to achieve precise adjustment of the opening and closing degrees of the two air valves to meet the air conditioning requirements under different working conditions.

[0055] A rooftop unit includes an economizer, which is the economizer mentioned above.

[0056] In this embodiment, the economizer is an air-side economizer, which is usually installed outdoors. When the economizer is used in a rooftop unit, the economizer is installed outdoors as part of the rooftop unit, and the rooftop unit is installed outdoors as a whole and connected to each room through pipelines. In this embodiment, a shell 1 is provided and the evaporator 5 and the blower 6 are also provided in the shell 1 to increase the compactness of the structure.

[0057] An integrated air conditioner includes an economizer, which is the above-mentioned economizer. A rooftop unit is a classification of the integrated air conditioner. In other embodiments, the integrated air conditioner can also be a dehumidifier according to usage requirements.

[0058] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0059] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. An economizer, characterized in that: include: Housing (1), fresh air damper (2) and return air damper (3); A fresh air chamber (101) and a return air chamber are provided in the housing (1), and the fresh air chamber (101) is provided with the fresh air valve (2); the return air chamber has a return air channel (102) and an exhaust air channel (103) that are isolated from each other, and the return air valve (3) is provided in the return air channel (102); the fresh air valve (2) is used to adjust the amount of fresh air intake, and the return air valve (3) is used to adjust the amount of return air sent to the indoor side; The shell (1) is provided with a first exhaust port (11) and a second exhaust port (12); the exhaust port of the exhaust channel (103) is connected to the first exhaust port (11), and the air inlet of the exhaust channel (103) is connected to the indoor side; the exhaust port of the return air channel (102) is connected to the second exhaust port (12), and the air inlet of the return air channel (102) is connected to the indoor side; a second exhaust valve (42) is provided at the second exhaust port (12), and the pressure drop in the exhaust channel (103) is smaller than the pressure drop in the return air channel (102).

2. The economizer according to claim 1, characterized in that The air inlet of the return air channel (102) is provided with a return air duct (121), and one end of the return air duct (121) facing away from the return air channel (102) is connected to the indoor side, and a return air passage is formed between the return air duct (121) and the return air channel (102), and the pressure drop in the exhaust channel (103) is smaller than the pressure drop in the return air passage.

3. The economizer according to claim 1, characterized in that A first exhaust valve (41) is provided at the first exhaust port (11), and the first exhaust valve (41) and the second exhaust valve (42) are both used to adjust the volume of return air discharged to the outdoor side.

4. The economizer according to claim 3, characterized in that The first exhaust valve (41) and the second exhaust valve (42) are both pressure relief valves. The return air valve (3) is arranged on the exhaust path of the return air channel (102). When the return air pressure at the return air valve (3) is lower than the ambient pressure outside the room, the first exhaust valve (41) opens. When the return air pressure at the return air valve (3) is higher than the ambient pressure outside the room, both the first exhaust valve (41) and the second exhaust valve (42) open.

5. The economizer according to claim 1, characterized in that It also includes a driving device, the fresh air valve (2) and the return air valve (3) are drivingly connected to the driving device, and the driving device is used to control the opening and closing degree of the fresh air valve (2) and the return air valve (3).

6. The economizer according to claim 1, characterized in that The housing (1) is further provided with a mixing chamber (104), and the air supply paths of the fresh air chamber (101) and the return air channel (102) respectively extend toward the mixing chamber (104).

7. The economizer according to claim 6, characterized in that An evaporator (5) and a blower (6) are also provided in the shell (1); the evaporator (5) is provided on the air outlet path of the mixing chamber (104); the blower (6) is provided on a side of the evaporator (5) facing away from the mixing chamber (104); an air outlet is provided on the shell (1); and the air outlet of the blower (6) faces the air outlet.

8. The economizer according to claim 7, characterized in that A mixed air temperature sensor is provided in the mixing chamber (104), or an outlet air temperature sensor is provided at the air supply port.

9. A rooftop unit, characterized in that: The economizer is comprised, and the economizer is the economizer according to any one of claims 1 to 8.

10. An integrated air conditioner, characterized in that: The economizer is comprised, and the economizer is the economizer according to any one of claims 1 to 8.

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