Fresh air system and regulation and control method

Abstract

The invention discloses a fresh air system and a regulation and control method. The fresh air system comprises a regulation and control device and a fresh air handling unit arranged outdoors. The fresh air handling unit comprises a mixing cavity and a main fan used for conveying outdoor fresh air to the mixing cavity. The mixing cavity communicates with the indoor space through an air return pipe and a fresh air pipe, and the air return pipe is used for collecting indoor return air, so that the indoor return air and the outdoor fresh air are mixed in the mixing cavity; the regulation and control device comprises a regulation controller, an indoor sensor group and an outdoor sensor group; the adjusting controller controls the fresh air handling unit to operate in a preset operation mode according to air quality parameters collected by the indoor sensor set and the outdoor sensor set. Wherein the air quality parameters comprise air temperature, humidity and / or carbon dioxide concentration. The fresh air system can be used in cooperation with a radiation air conditioner, the indoor air quality can be improved, and energy consumption is reduced.

Description

Technical Field

[0001] The present application relates to the field of air conditioning technology, and in particular to a fresh air system and a control method. Background Art

[0002] Housing is one of the most basic means of production and living for human survival and development. my country's housing construction is accelerating, the scale of housing supply is increasing, and residents' housing conditions are significantly improved. With the advancement of urbanization and the improvement of living standards, residents' demand for healthy and comfortable quality of building environment is also increasing. The consumption demand of domestic building products has shifted from quantity to quality. Radiant air conditioning is widely used in high-end residences, nursing homes, office buildings and other places due to its advantages of uniform temperature and energy saving and environmental protection. In radiant air-conditioned residences, fresh air systems play a key role. With the improvement of residential quality, in order to meet energy-saving design standards, buildings must have good air tightness and thermal insulation performance. Indoor and outdoor air exchange requires the support of mechanical systems, and sufficient fresh air volume must be ensured. The fresh air system not only affects the indoor air quality, but also affects the user's perception of the thermal and humid environment. In actual projects, the radiant air conditioning design of high-end residences (such as technology residences) often faces the problem of large investment and poor effect of fresh air systems designed according to the existing standard system. During the fresh air treatment process, the distribution and organization of the fresh air treatment process will consume a certain amount of energy. In addition, the enclosure structure of high-quality residential buildings must have good thermal insulation properties, which will significantly increase the energy consumption ratio of the fresh air system, sometimes even more than half.

[0003] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the application and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to ordinary technicians in the field. Summary of the invention

[0004] The purpose of this application is to provide a fresh air system and a control method that can be used in conjunction with existing radiant air conditioning, which helps to reduce energy consumption and achieve the goal of energy conservation and carbon reduction in buildings.

[0005] In order to achieve the above objectives, this application is implemented by adopting the following technical solutions: On the one hand, the present application provides a fresh air system, including a control device and a fresh air unit arranged outdoors; The fresh air unit comprises a mixing cavity and a main fan for conveying outdoor fresh air to the mixing cavity; The mixing cavity is connected to the indoor through the return air duct and the fresh air duct respectively. The return air duct is used to collect the indoor return air so that the indoor return air and the outdoor fresh air are mixed in the mixing cavity; The control device includes a control controller, an indoor sensor group and an outdoor sensor group; the control controller controls the fresh air unit to operate in a predetermined operation mode according to the air quality parameters collected by the indoor sensor group and the outdoor sensor group; The air quality parameters include air temperature, humidity and / or carbon dioxide concentration.

[0006] Furthermore, an air valve with adjustable opening is installed on the return air duct, and the regulating controller adjusts the opening of the air valve and / or the operating power of the main fan according to the collected air quality parameters.

[0007] Furthermore, the fresh air unit also includes a filter for filtering the mixed air output from the mixing cavity.

[0008] Further, the outdoor sensor group includes an outdoor fresh air temperature and humidity sensor provided at the air outlet of the main fan, a return air temperature and humidity sensor provided at the air outlet of the return air duct, and / or a mixed air temperature and humidity sensor provided at the air outlet of the mixing chamber; The indoor sensor group also includes an indoor temperature and humidity sensor, an indoor carbon dioxide sensor and / or a radiation panel temperature sensor attached to the ceiling of the indoor radiation air conditioner; The regulating controller regulates the operating power of the main fan according to the signal collected by the radiation panel temperature sensor so that the surface temperature of the radiation panel is not lower than the dew point; The regulating controller is connected to the indoor exhaust fan signal, and adjusts the opening of the air valve, the operating power of the main fan and / or the operating power of the indoor exhaust fan according to the signal collected by the indoor carbon dioxide sensor.

[0009] Furthermore, the control device also includes a human-computer interaction panel, through which the user can set the operation mode of the fresh air system and the trigger conditions of various operation modes, wherein the trigger conditions include threshold values ​​of air quality parameters.

[0010] Furthermore, the fresh air unit also includes a compressor, a condenser, an expansion valve and an evaporator. When the fresh air unit operates in a dehumidification mode and is used to condense and dehumidify the air delivered to the room, the compressor, condenser, expansion valve and evaporator are connected in sequence; when the fresh air unit operates in an auxiliary heating mode and is used to auxiliary heat the air delivered to the room, the compressor, evaporator, condenser and expansion valve are connected in sequence.

[0011] In another aspect, the present application provides a control method for a fresh air system, the control method comprising the following steps: Collecting the indoor air temperature, and in response to the indoor air temperature being higher than a set upper limit of the summer indoor temperature, triggering a summer operation condition, including: Collect indoor air humidity; In response to the indoor air humidity being higher than a set upper limit of the indoor air humidity, controlling the fresh air unit to operate in a dehumidification mode; In response to the indoor air humidity being lower than a set indoor air humidity lower limit and the indoor carbon dioxide concentration being higher than a set indoor carbon dioxide concentration upper limit, controlling the fresh air unit to operate in a ventilation mode; In response to the indoor air humidity being between the set indoor air humidity upper limit and the indoor air humidity lower limit, and the indoor carbon dioxide concentration being not higher than the set indoor carbon dioxide concentration upper limit, controlling the fresh air unit to enter a dormant state; and / or, The control method comprises the following steps: Collecting the indoor air temperature, in response to the indoor air temperature being lower than the set lower limit of the winter indoor temperature and higher than the set lower limit of the fresh air unit operating temperature, triggering the winter operating condition, including: Collect outdoor air temperature; In response to the outdoor air temperature being higher than the set lower limit of the indoor temperature in winter, controlling the fresh air unit to operate in a ventilation mode; In response to the outdoor air temperature being not higher than the set lower limit of the winter indoor temperature, the fresh air unit is controlled to operate in an auxiliary heating mode to assist the indoor radiation air conditioning in heating; and / or, The control method comprises the following steps: Collecting the indoor air temperature, and in response to the indoor air temperature being between the set upper limit of the summer indoor temperature and the lower limit of the winter indoor temperature, triggering the transition season operation condition, including: Collect indoor air humidity; In response to the indoor air humidity being higher than a set upper limit of the indoor air humidity, controlling the fresh air unit to operate in a dehumidification mode; In response to the indoor air humidity being not higher than the set upper limit of the indoor air humidity, controlling the fresh air unit to operate in a ventilation mode; In response to the indoor air humidity being between a set upper limit of the indoor air humidity and a set lower limit of the indoor air humidity, the fresh air unit is controlled to enter a dormant state.

[0012] Furthermore, under the operating condition of the transition season, the control of the fresh air unit to operate in the dehumidification mode includes: Turning on the main fan in the fresh air unit; According to the humidity of outdoor fresh air and indoor return air, adjust the opening of the air valve on the return air duct, and adjust the indoor air humidity by changing the mixing ratio of outdoor fresh air and indoor return air.

[0013] Furthermore, in summer operating conditions, the control of the fresh air unit to operate in a dehumidification mode includes: The high-temperature and low-pressure refrigerant gas is compressed by the compressor in the fresh air unit to obtain the high-temperature and high-pressure refrigerant gas; The high-temperature and high-pressure refrigerant gas is cooled by the condenser in the fresh air unit to obtain medium-temperature and high-pressure refrigerant gas; The expansion valve in the fresh air unit is used to throttle and reduce the pressure of the medium-temperature and high-pressure refrigerant gas to obtain low-temperature and low-pressure refrigerant gas; The evaporator in the fresh air unit uses low-temperature and low-pressure refrigerant gas to condense and dehumidify the air delivered to the room. The high-temperature and low-pressure refrigerant gas generated after heat exchange re-enters the compressor to achieve cyclic dehumidification.

[0014] Furthermore, the method further comprises: Collect indoor carbon dioxide concentration; In response to the indoor carbon dioxide concentration being higher than the set indoor carbon dioxide concentration upper limit, reducing the indoor return air and increasing the operating power of the main fan and the indoor exhaust fan; In response to the indoor carbon dioxide concentration being lower than the set indoor carbon dioxide concentration lower limit, increasing the indoor return air and reducing the operating power of the main fan and the indoor exhaust fan; In response to the indoor carbon dioxide concentration being between a set indoor carbon dioxide concentration upper limit and an indoor carbon dioxide concentration lower limit, the indoor return air is increased, and the operating power of the main fan and the indoor exhaust fan is reduced.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The fresh air system provided in the present application is provided with a return air duct for collecting indoor return air. Under some operating conditions, the outdoor fresh air delivered by the main fan and the indoor return air can be mixed in the mixing chamber, thereby reducing the processing volume of the fresh air system for delivering indoor air, thereby improving energy utilization and reducing energy consumption; under certain operating conditions, the fresh air system can cooperate with radiant air conditioning to adjust the temperature, humidity and carbon dioxide concentration of the indoor air, thereby improving the indoor air quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 is a schematic diagram of the structure of the fresh air system provided by the present application in some embodiments; Figure 2 This is a circuit principle block diagram of the control device in the fresh air system provided by the present application; Description of reference numerals: 1-main fan; 2-outdoor fresh air temperature and humidity sensor; 3-return air temperature and humidity sensor; 4-mixing chamber; 5-air valve; 6. Mixed air temperature and humidity sensor; 7-filter; 8-fresh air unit; 10-regulating controller; 11-human-computer interaction panel; 12-radiation panel temperature sensor; 13-carbon dioxide sensor; 14-indoor temperature and humidity sensor; 15-exhaust fan. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use.

[0019] Embodiment 1

[0020] The embodiment provides a fresh air system, which mainly includes a control device and a fresh air unit 8 arranged outdoors. Figure 1 As shown, the fresh air unit 8 includes a mixing cavity 4 and a main fan 1, and the main fan 1 is used to deliver outdoor fresh air to the mixing cavity 4. At the same time, the mixing cavity 4 is also connected to a return air duct 3, through which the indoor return air can be collected, and the indoor return air and the outdoor fresh air can be mixed in the mixing cavity 4 to form mixed air. The mixing cavity 4 is also connected to the room through the fresh air duct, which is used to deliver the processed mixed air to the room.

[0021] The control device includes a control controller 10, an indoor sensor group and an outdoor sensor group; the control controller 10 controls the fresh air unit 8 to operate in a predetermined operating mode according to the air quality parameters collected by the indoor sensor group and the outdoor sensor group; wherein the air quality parameters include air temperature, humidity and / or carbon dioxide concentration.

[0022] In summary, the fresh air system provided in this embodiment is provided with a return air duct 3 for collecting indoor return air. Under some operating conditions, the outdoor fresh air delivered by the main fan 1 and the indoor return air can be mixed in the mixing chamber, thereby reducing the processing volume of the fresh air system for the air delivered to the indoor room, thereby improving energy utilization and reducing energy consumption.

[0023] In some embodiments, a wind valve 5 with adjustable opening is installed on the return air duct 3. The regulating controller 10 can adjust the opening of the wind valve 5 to adjust the return air volume of the indoor return air according to the collected air quality parameters, thereby changing the mixing ratio of the indoor return air and the outdoor fresh air, so as to achieve the air quality expected by the user more efficiently and accurately.

[0024] It should be understood that in order to change the mixing ratio of indoor return air and outdoor fresh air in the mixing chamber 4, the operating power of the main fan 1 can also be adjusted to achieve the purpose of changing the mixing ratio by increasing or decreasing the supply volume of outdoor fresh air; or the purpose of changing the mixing ratio more quickly can be achieved by combining adjusting the opening of the air valve 5 and the operating power of the main fan 1.

[0025] In some embodiments, the fresh air unit 8 provided in the present application further includes a filter 7 for filtering the mixed air output from the mixing chamber 4. In the ventilation mode, the fresh air unit 8 does not need to perform temperature and humidity control on the mixed air, and the mixed air can be filtered by the filter 7 and then delivered to the room.

[0026] In some embodiments, the outdoor sensor group includes an outdoor fresh air temperature and humidity sensor 2 provided at the outlet of the main fan 1, a return air temperature and humidity sensor provided at the outlet of the return air duct 3, and / or a mixed air temperature and humidity sensor 6 provided at the outlet of the mixing chamber; the indoor sensor group includes an indoor temperature and humidity sensor 14, an indoor carbon dioxide sensor 13 and / or a radiation panel temperature sensor 12 attached to the ceiling of the indoor radiation air conditioner. Figure 2 As shown, each sensor in the outdoor sensor group and the indoor sensor group is connected to a different signal input terminal of the regulating controller 10 respectively.

[0027] The temperature and humidity of the outdoor air can be detected by the outdoor fresh air temperature and humidity sensor 2, and the temperature and humidity of the indoor air can be detected by the indoor temperature and humidity sensor 14. The adjustment controller 10 controls the operation mode of the fresh air unit 8 by comparing the temperature of the outdoor air with the temperature of the indoor air. For example, in winter operation conditions, when the temperature of the outdoor air is greater than the temperature of the indoor air, the fresh air unit 8 can be operated in the ventilation mode to increase the indoor temperature or assist the indoor radiation air conditioner to quickly increase the indoor temperature. For another example, assuming that the humidity of the current indoor air is higher than the upper limit of the indoor air humidity set by the user, if at this time, the humidity of the outdoor air is lower than the humidity of the indoor air, the fresh air unit 8 can be operated in the dehumidification mode, and the humidity of the indoor air can be adjusted by adjusting the mixing ratio of the outdoor fresh air and the indoor return air.

[0028] Carbon dioxide concentration is also an important indicator for measuring indoor air quality. The regulating controller 10 can detect the carbon dioxide concentration in the indoor air according to the indoor carbon dioxide sensor 13, compare the detected carbon dioxide concentration with the carbon dioxide concentration threshold set by the user, and adjust the mixing ratio of indoor return air and outdoor fresh air according to the comparison result. For example, when the carbon dioxide concentration in the indoor air exceeds the upper limit of carbon dioxide concentration set by the user, it means that the return air volume of the indoor return air should be reduced or the delivery volume of outdoor fresh air should be increased. The regulating controller 10 can increase the operating power of the main fan 1 and / or reduce the opening of the air valve 5.

[0029] In some embodiments of the present application, in order to improve the indoor air quality as quickly as possible, the regulating controller 10 is also connected to the signal of the indoor exhaust fan 15, and adjusts the opening of the air valve 5, the operating power of the main fan 1 and / or the operating power of the indoor exhaust fan 15 according to the signal collected by the indoor carbon dioxide sensor 13.

[0030] In order to avoid the phenomenon that water vapor in the air condenses when it encounters cold and causes condensation on the surface of the radiation panel, the regulating controller 10 can also adjust the operating power of the main fan 1 according to the signal collected by the radiation panel temperature sensor 12 so that the surface temperature of the radiation panel is not lower than the dew point.

[0031] In some embodiments, the control device further includes a human-machine interaction panel 11, through which a user can set an operation mode of the fresh air system and trigger conditions of various operation modes, wherein the trigger conditions include thresholds of air quality parameters. As an embodiment, the human-machine interaction interface can be set indoors, and the adjustment controller 10 can be set outdoors.

[0032] In some embodiments, the fresh air unit 8 also includes a compressor, a condenser, an expansion valve and an evaporator. If the fresh air unit 8 works in the condensation and dehumidification mode, the refrigerant passes through the compressor, condenser, expansion valve and evaporator in sequence, and the specific processing process is as follows: the high-temperature and low-pressure refrigerant gas obtained in the previous cycle is compressed by the compressor in the fresh air unit 8 to obtain a high-temperature and high-pressure refrigerant gas; the high-temperature and high-pressure refrigerant gas is cooled by the condenser to obtain a medium-temperature and high-pressure refrigerant gas; the expansion valve throttles and reduces the pressure of the medium-temperature and high-pressure refrigerant gas to obtain a low-temperature and low-pressure refrigerant gas; the low-temperature and low-pressure refrigerant gas flows into the evaporator to evaporate, and the air delivered to the room is condensed and dehumidified by evaporation heat absorption. The high-temperature and low-pressure refrigerant gas generated after the refrigerant gas heat exchange in the evaporator re-enters the next cycle, that is, re-enters the compressor to achieve cyclic condensation and dehumidification of the air.

[0033] In some embodiments, the fresh air unit 8 provided in the present application can also work in an auxiliary heating mode. In winter operating conditions, if the indoor air temperature is lower than the set lower limit of the winter indoor temperature, the fresh air unit 8 can be turned on for auxiliary heating while the indoor radiation air conditioner is turned on. The working process of the fresh air unit 8 in the auxiliary heating mode is as follows: The low-temperature and low-pressure refrigerant gas obtained in the previous cycle is compressed by the compressor to obtain low-temperature and high-pressure refrigerant gas. The low-temperature and high-pressure refrigerant gas enters the evaporator to evaporate and absorb heat, and is converted into high-temperature and high-pressure refrigerant gas. The high-temperature and high-pressure refrigerant gas exchanges heat with the air delivered to the room through the condenser, so that the temperature of the air delivered to the room increases, and at the same time, the high-temperature and high-pressure refrigerant gas is converted into medium-temperature and high-pressure refrigerant gas. The medium-temperature and high-pressure refrigerant gas is throttled and reduced in pressure through the expansion valve, and is converted into low-temperature and low-pressure refrigerant gas to enter the next cycle.

[0034] The fresh air system provided in this embodiment can be used in conjunction with indoor radiation air conditioning to improve energy utilization efficiency and reduce energy consumption.

[0035] Embodiment 2

[0036] This embodiment provides a control method for a fresh air system, which can be implemented by the fresh air system provided in the first embodiment, and mainly includes summer operation conditions, winter operation conditions and transition operation conditions. The basis for the division of each operation condition is air temperature. Specifically: when the indoor air temperature is higher than the set summer indoor temperature upper limit t w1 When the indoor air temperature is lower than the set winter indoor temperature lower limit t w2 When t w2 <t w1 The triggering condition of the so-called transitional operating condition is: the indoor air temperature is between t w1 and t w2between.

[0037] It should be noted that the above three operating conditions can be implemented separately or in combination with each other. For example, the control method for the summer operating condition and the control method for the winter operating condition provided in this embodiment are respectively operated in summer and winter, and other possible control methods are adopted in transitional operating conditions; or the control method for the summer operating condition and the control method for the transitional operating condition are used in combination, and other possible control methods are adopted for the winter operating condition.

[0038] The control methods for each operating condition are further described in detail below: (1) In summer operation conditions, the control method comprises the following steps: The indoor air temperature is collected, and in response to the indoor air temperature being higher than the set upper limit of the summer indoor temperature, the summer operation condition is triggered. Under the summer operation condition, the humidity and carbon dioxide concentration of the indoor air are mainly adjusted. For this purpose, the further control method includes the following steps: Collect indoor air humidity ; In response to the indoor air humidity being higher than the set indoor air humidity upper limit ,Right now > , control the fresh air unit 8 to operate in the dehumidification mode; In response to the indoor air humidity being lower than the set indoor air humidity lower limit ,Right now < , and the indoor carbon dioxide concentration Higher than the set upper limit of indoor carbon dioxide concentration , control the fresh air unit 8 to operate in ventilation mode; In response to the indoor air humidity being at a set indoor air humidity upper limit and the lower limit of indoor air humidity and the indoor carbon dioxide concentration is not higher than the set indoor carbon dioxide concentration upper limit , control the fresh air unit 8 to enter the sleep state.

[0039] For controlling the fresh air unit 8 to operate in the dehumidification mode as described in the present embodiment, there are at least two control methods: the first method is: if the humidity of the outdoor fresh air is lower than the humidity of the indoor air, the purpose of dehumidifying the indoor air can be achieved by mixing the outdoor fresh air with the indoor return air and adjusting the mixing ratio of the two. In this dehumidification mode, it helps to reduce the energy consumption of the system; the second method is: if the humidity of the outdoor fresh air is not lower than the humidity of the indoor air, the fresh air unit 8 can be used for condensation dehumidification. This dehumidification mode can improve the dehumidification efficiency.

[0040] The control methods for these two dehumidification modes are further described in detail below: For the first dehumidification mode, the humidity of the outdoor fresh air is first detected. In response to the humidity of the outdoor fresh air being lower than the humidity of the indoor air, the main fan 1 in the fresh air unit 8 is turned on. According to the humidity of the outdoor fresh air and the humidity of the indoor return air, the opening of the air valve 5 on the return air duct 3 is adjusted. By changing the mixing ratio of the outdoor fresh air and the indoor return air, the indoor air humidity is adjusted. Considering that there may be a large temperature difference between the outdoor fresh air and the indoor air in winter and summer, the introduction of outdoor fresh air may cause fluctuations in the indoor air temperature. Therefore, this dehumidification mode is more suitable for dehumidification under transitional operating conditions. In this mode, the purpose of dehumidification can be achieved by simply turning on the main fan 1 and adjusting the opening of the air valve 5, which is obviously more helpful in reducing the energy consumption of the fresh air system.

[0041] For the second dehumidification mode, the main steps include: The high-temperature and low-pressure refrigerant gas generated in the previous cycle is compressed by the compressor in the fresh air unit 8 to obtain high-temperature and high-pressure refrigerant gas; The high-temperature and high-pressure refrigerant gas is cooled by the condenser in the fresh air unit 8 to obtain medium-temperature and high-pressure refrigerant gas; The expansion valve in the fresh air unit 8 is used to throttle and reduce the pressure of the medium-temperature and high-pressure refrigerant gas to obtain a low-temperature and low-pressure refrigerant gas; The evaporator in the fresh air unit 8 utilizes low-temperature and low-pressure refrigerant gas to condense and dehumidify the air delivered to the room, and the high-temperature and low-pressure refrigerant gas generated after heat exchange re-enters the compressor, thereby realizing cyclic dehumidification.

[0042] In the second dehumidification mode, the air temperature after condensation dehumidification will be lower than the outdoor fresh air temperature or indoor return air, thereby having a certain cooling effect. Therefore, the second dehumidification mode is more suitable for summer operating conditions. It can assist in cooling while dehumidifying. The second dehumidification mode can achieve the purpose of indoor air dehumidification more efficiently.

[0043] In winter operation conditions, the regulation of indoor air temperature is mainly considered. The fresh air unit 8 can assist the indoor radiation air conditioning heating in winter operation conditions. The regulation method in winter operation conditions is further explained in detail below: Collect the indoor air temperature, in response to the indoor air temperature being lower than the set lower limit of the winter indoor temperature and higher than the set lower limit of the operating temperature of the fresh air unit 8 t w3 When the winter operation condition is triggered, it includes: Collect outdoor air temperature; In response to the outdoor air temperature being higher than the set lower limit of the indoor temperature in winter, the fresh air unit 8 is controlled to operate in the ventilation mode; In response to the outdoor air temperature being not higher than the set lower limit of the indoor temperature in winter, the fresh air unit 8 is controlled to operate in the auxiliary heating mode to assist the indoor radiation air-conditioning heating.

[0044] The auxiliary heating mode of the fresh air unit 8 can reduce the energy consumption of indoor radiation air conditioning. The control method of the auxiliary heating mode of the fresh air unit 8 is further described in detail below: The low-temperature and low-pressure refrigerant gas obtained in the previous cycle is compressed by a compressor to obtain low-temperature and high-pressure refrigerant gas, which enters the evaporator to evaporate and absorb heat, and is converted into high-temperature and high-pressure refrigerant gas; the high-temperature and high-pressure refrigerant gas exchanges heat with the air delivered to the room through the condenser, so that the temperature of the air delivered to the room increases, and at the same time, the high-temperature and high-pressure refrigerant gas is converted into medium-temperature and high-pressure refrigerant gas, which is throttled and reduced in pressure by the expansion valve, and is converted into low-temperature and low-pressure refrigerant gas to enter the next cycle.

[0045] For the transition season operation condition, this embodiment mainly considers the humidity regulation of indoor air, and the control method includes the following steps: Collecting the indoor air temperature, and in response to the indoor air temperature being between the set upper limit of the summer indoor temperature and the lower limit of the winter indoor temperature, triggering the transition season operation condition, including: Collect indoor air humidity; In response to the indoor air humidity being higher than the set upper limit of the indoor air humidity, the fresh air unit 8 is controlled to operate in the dehumidification mode; the specific control method of the dehumidification mode here can refer to the first dehumidification mode mentioned above, which will not be described in detail here; In response to the indoor air humidity being not higher than the set upper limit of the indoor air humidity, controlling the fresh air unit 8 to operate in the ventilation mode; In response to the indoor air humidity being between the set upper limit and lower limit of the indoor air humidity, the fresh air unit 8 is controlled to enter a dormant state.

[0046] The aforementioned control of the fresh air unit 8 to operate in the ventilation mode means that only the air input into the room is filtered without any other processing, and the corresponding relevant processing equipment in the fresh air unit 8 is in a shutdown state. For the dormant state, it means shutting down the entire fresh air unit 8, so that the entire fresh air system enters a dormant and stopped state.

[0047] Carbon dioxide concentration is also an important indicator for measuring indoor air quality. For this reason, the control method provided by this application also includes: Collect indoor carbon dioxide concentration; In response to the indoor carbon dioxide concentration being higher than the set indoor carbon dioxide concentration upper limit, reducing the indoor return air and increasing the operating power of the main fan 1 and the indoor exhaust fan 15; In response to the indoor carbon dioxide concentration being lower than the set indoor carbon dioxide concentration lower limit, the indoor return air is increased, and the operating power of the main fan 1 and the indoor exhaust fan 15 is reduced; In response to the indoor carbon dioxide concentration being between the set indoor carbon dioxide concentration upper limit and the indoor carbon dioxide concentration lower limit, the indoor return air is increased, and the operating power of the main fan 1 and the indoor exhaust fan 15 is reduced.

[0048] In summary, the fresh air system provided in the present application can operate independently, and under certain operating conditions, it can also cooperate with radiant air conditioning to adjust the temperature, humidity and carbon dioxide concentration of indoor air, thereby improving indoor air quality and reducing energy consumption.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0050] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A fresh air system, characterized in that: It includes a control device and a fresh air unit installed outdoors; The fresh air unit comprises a mixing cavity and a main fan for conveying outdoor fresh air to the mixing cavity; The mixing cavity is connected to the indoor through the return air duct and the fresh air duct respectively. The return air duct is used to collect the indoor return air so that the indoor return air and the outdoor fresh air are mixed in the mixing cavity; The control device includes a control controller, an indoor sensor group and an outdoor sensor group; the control controller controls the fresh air unit to operate in a predetermined operation mode according to the air quality parameters collected by the indoor sensor group and the outdoor sensor group; The air quality parameters include air temperature, humidity and / or carbon dioxide concentration.

2. The fresh air system according to claim 1, characterized in that: The return air duct is provided with an air valve with adjustable opening, and the regulating controller regulates the opening of the air valve and / or the operating power of the main air blower according to the collected air quality parameters.

3. The fresh air system according to claim 1, characterized in that: The fresh air unit also includes a filter for filtering the mixed air output from the mixing cavity.

4. The fresh air system according to claim 2, characterized in that: The outdoor sensor group includes an outdoor fresh air temperature and humidity sensor provided at the air outlet of the main fan, a return air temperature and humidity sensor provided at the air outlet of the return air duct, and / or a mixed air temperature and humidity sensor provided at the air outlet of the mixing chamber; The indoor sensor group also includes an indoor temperature and humidity sensor, an indoor carbon dioxide sensor and / or a radiation panel temperature sensor attached to the ceiling of the indoor radiation air conditioner; The regulating controller regulates the operating power of the main fan according to the signal collected by the radiation panel temperature sensor so that the surface temperature of the radiation panel is not lower than the dew point; The regulating controller is connected to the indoor exhaust fan signal, and adjusts the opening of the air valve, the operating power of the main fan and / or the operating power of the indoor exhaust fan according to the signal collected by the indoor carbon dioxide sensor.

5. The fresh air system according to claim 1, characterized in that: The control device also includes a human-computer interaction panel, through which the user can set the operation mode of the fresh air system and the trigger conditions of various operation modes, wherein the trigger conditions include the threshold values ​​of air quality parameters.

6. The fresh air system according to any one of claims 1 to 5, characterized in that: The fresh air unit also includes a compressor, a condenser, an expansion valve and an evaporator. When the fresh air unit operates in a dehumidification mode and is used to condense and dehumidify the air delivered to the room, the compressor, condenser, expansion valve and evaporator are connected in sequence; when the fresh air unit operates in an auxiliary heating mode and is used to auxiliary heat the air delivered to the room, the compressor, evaporator, condenser and expansion valve are connected in sequence.

7. A method for controlling a fresh air system according to any one of claims 1 to 6, characterized in that: The control method comprises the following steps: Collecting the indoor air temperature, and in response to the indoor air temperature being higher than a set upper limit of the summer indoor temperature, triggering a summer operation condition, including: Collect indoor air humidity; In response to the indoor air humidity being higher than a set upper limit of the indoor air humidity, controlling the fresh air unit to operate in a dehumidification mode; In response to the indoor air humidity being lower than a set indoor air humidity lower limit and the indoor carbon dioxide concentration being higher than a set indoor carbon dioxide concentration upper limit, controlling the fresh air unit to operate in a ventilation mode; In response to the indoor air humidity being between the set indoor air humidity upper limit and the indoor air humidity lower limit, and the indoor carbon dioxide concentration being not higher than the set indoor carbon dioxide concentration upper limit, controlling the fresh air unit to enter a dormant state; and / or, The control method comprises the following steps: Collecting the indoor air temperature, in response to the indoor air temperature being lower than the set lower limit of the winter indoor temperature and higher than the set lower limit of the fresh air unit operating temperature, triggering the winter operating condition, including: Collect outdoor air temperature; In response to the outdoor air temperature being higher than the set lower limit of the indoor temperature in winter, controlling the fresh air unit to operate in a ventilation mode; In response to the outdoor air temperature being not higher than the set lower limit of the winter indoor temperature, the fresh air unit is controlled to operate in an auxiliary heating mode to assist the indoor radiation air conditioning in heating; and / or, The control method comprises the following steps: Collecting the indoor air temperature, and in response to the indoor air temperature being between the set upper limit of the summer indoor temperature and the lower limit of the winter indoor temperature, triggering the transition season operation condition, including: Collect indoor air humidity; In response to the indoor air humidity being higher than a set upper limit of the indoor air humidity, controlling the fresh air unit to operate in a dehumidification mode; In response to the indoor air humidity being not higher than the set upper limit of the indoor air humidity, controlling the fresh air unit to operate in a ventilation mode; In response to the indoor air humidity being between a set upper limit of the indoor air humidity and a set lower limit of the indoor air humidity, the fresh air unit is controlled to enter a dormant state.

8. The method according to claim 7, characterized in that Under the operating condition of the transition season, the control of the fresh air unit to operate in the dehumidification mode includes: Turning on the main fan in the fresh air unit; According to the humidity of outdoor fresh air and indoor return air, adjust the opening of the air valve on the return air duct, and adjust the indoor air humidity by changing the mixing ratio of outdoor fresh air and indoor return air.

9. The method according to claim 7, characterized in that: In summer operation, the control of the fresh air unit to operate in dehumidification mode includes: The high-temperature and low-pressure refrigerant gas is compressed by the compressor in the fresh air unit to obtain the high-temperature and high-pressure refrigerant gas; The high-temperature and high-pressure refrigerant gas is cooled by the condenser in the fresh air unit to obtain medium-temperature and high-pressure refrigerant gas; The expansion valve in the fresh air unit is used to throttle and reduce the pressure of the medium-temperature and high-pressure refrigerant gas to obtain low-temperature and low-pressure refrigerant gas; The evaporator in the fresh air unit uses low-temperature and low-pressure refrigerant gas to condense and dehumidify the air delivered to the room. The high-temperature and low-pressure refrigerant gas generated after heat exchange re-enters the compressor to achieve cyclic dehumidification.

10. The method according to claim 7, characterized in that The method further comprises: Collect indoor carbon dioxide concentration; In response to the indoor carbon dioxide concentration being higher than the set indoor carbon dioxide concentration upper limit, reducing the indoor return air and increasing the operating power of the main fan and the indoor exhaust fan; In response to the indoor carbon dioxide concentration being lower than the set indoor carbon dioxide concentration lower limit, increasing the indoor return air and reducing the operating power of the main fan and the indoor exhaust fan; In response to the indoor carbon dioxide concentration being between a set indoor carbon dioxide concentration upper limit and an indoor carbon dioxide concentration lower limit, the indoor return air is increased, and the operating power of the main fan and the indoor exhaust fan is reduced.

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