194 results about "Transition season" patented technology

The invention discloses a temperature control dehumidification system and a temperature control dehumidification method for the fresh air of a radiation air conditioner. The system comprises an air duct system, a radiation water circulation system and a cooling system, wherein the air duct system comprises a fresh return air treatment air duct and an exhaust air heat recovery air duct, which are independent; a pre-cooler/pre-heater and a temperature control heat exchanger are integrated corrugated finned type internally-threaded coiled pipes, and are connected with a radiation water inlet/outlet pipeline to form the radiation water circulation system; one stage of evaporator is used for direct evaporation, and two stages of condensers are connected in parallel to form a double-stage condensation cooling compression system. The system can be combined with the radiation air conditioner to independently control temperature and humidity, and besides a conditioning treatment function of a conventional dehumidification system, the system also has an exhaust air heat recovery function; a household compression cooling air conditioner is combined with the dehumidification system to realize cooling in summer, heating in winter and humidification in transition seasons; the running energy consumption is greatly lowered, and the shortcomings of dehumidification incapability and high condensation rate of the radiation air conditioner are overcome.

The invention provides a central air-conditioning control system and a control method thereof, and belongs to the technical field of air-conditioning systems. The central air-conditioning control system comprises a universal equipment model library, an equipment performance testing module, a comfort level evaluating module, a genetic algorithm multi-objective optimization control module and an execution module. An actual measured method is used, a system model is established, and the central air-conditioning control system is high in precision and high in reliability and is adaptive; a genetic algorithm is used, multi-objective optimizing can be realized, the optimizing efficiency is high, the comfort level is high, energy is saved, and the cost is low; whether a user feels comfortable or not can be intelligently judged by a user behavior recognition mode, and control objectives are adjusted in time; and the control method can be optimal on the basis of environmental change, particularly at the transition season, the equipment efficiency can be greatly improved, and energy conservation and emission reduction are realized.

An air treatment device with natural cold and heat supply includes a compressor, a four-way valve, a gas liquid separator, a condenser, a throttling means and an evaporator. The invention is characterized in that: a heating pipe valve and a heating pump valve are added on the pipeline where the four-way valve is disposed, valves are in parallel connection with both ends of the throttling means, wherein, a high position machine and a low position machine are provided for accommodating the corresponding components. According to the invention, refrigeration and heating functions of the original system is reserved, furthermore, a heating pipe natural circulation is introduced, thereby, energy waste problem in winter and transition seasons for water circulation heating pump system building can be resolved, meanwhile, the high position energy loss during complementing heat in winter is avoided. A refrigeration agent can be additionally provided in the invention to maintain the operation performance of the heating pipe circulation, thus further increasing the energy-saving performance and the reliability of the heating pump air conditioning system. The invention is applicable for the other situations to transfer heat from the high temperature fluid end to the low temperature fluid end, and has advantages of energy-saving and reliability.

The invention provides a fresh air handling unit adjusting and controlling system suitable for a radiant air conditioner and a controlling method of the fresh air handling unit adjusting and controlling system. The fresh air handling unit adjusting and controlling system is used by cooperating with a radiant air conditioner system in an indoor space; a fresh air dehumidifying unit is adopted to bear the fresh air load, the humidity load and part of indoor sensible heat load; a fresh air handling unit can achieve the different functions of filtering, cooling, dehumidifying, auxiliary heating, ventilating and the like according to season requirements and the outdoor fresh air state; in addition, two air supply channels, that is, the main air channel and the bypass air channel are designed in a fresh air handling unit indoor unit, gating is conducted through a gating valve, and thus the fresh air handling unit indoor unit can operate in different working modes through free switching; and through control of an adjusting and controlling device over the operation modes, an auxiliary radiating system adjusts the air environment of the indoor space, the indoor environment comfort level and the system operation energy efficiency ratio can be effectively increased, and the problems that the fresh air conveying energy efficiency ratio in the transition season is insufficient, the room temperature and humidity are unreasonable, moisture condensates on the surface of a radiant panel, and energy sources are consumed excessively are solved.

The invention discloses a combined air conditioning system for a machine room and a control method thereof. The system comprises a refrigerating system, a heat tube unit and a three-way valve, wherein the refrigerating unit comprises one or a plurality of compressors, a refrigerating condenser, a throttling device and a low-pressure liquid storing device; the heat tube unit comprises the low-pressure liquid storing device, an evaporator, a refrigerant pump and a heat tube condenser; the refrigerating unit and the heat tube unit are coupled through the low-pressure liquid storing device. The combined air conditioning system for the machine room is characterized in that the temperature of a refrigerant in the low-pressure liquid storing device can be controlled and treated as the precise control parameter of system cold output; the three-way valve can be controlled to switch to correspondingly perform refrigerating circulating, combined circulating and heat tube circulating according to the outdoor environmental temperature, so as to meet the refrigerating demands of the machine room and a base station on all-weather air conditioning; the natural cold sources from day to night, transition season and winter can be utilized to the maximum. The system is compact in structure design, high in reliability, energy-saving, environmentally-friendly, high in thermal efficiency, high in stability, and high in adjusting accuracy.

The invention relates to an all-year cold supply chiller with natural cooling function. A compressor, an air connecting pipe, a condenser, a liquid connecting pipe, a throttling gear and an evaporator form a steam compression type refrigeration circulation loop; the evaporator, the air connecting pipe, the condenser arranged on the evaporator and the liquid connecting pipe, which are all in the steam compression type refrigeration circulation loop form a cold medium natural circulation loop by opening a heat pipe air valve on a heat pipe branch and a heat pipe liquid valve connected in parallel with the throttling gear, and closing a refrigeration air valve on an air suction pipe of the compressor. The all-year cold supply chiller can adopt an integral structure or a split structure, keeps the function of making air conditioning cold water in summer, can sufficiently utilize the natural cold energy of outdoor air to make cold water in transition seasons and winter, provides cold water for all-year cold supply areas, such as inner zone of buildings and highly heating areas, and has the remarkable advantages of simple structure, high efficiency and energy saving.

The invention discloses a combined refrigeration and multi-connected air conditioning system which is characterized in that a cold source system of the multi-connected air conditioning system, which is composed of two or more than two outdoor composite refrigeration modules is arranged outdoors; each outdoor combined refrigeration module is formed by compositing a first refrigerant vapor compression refrigeration cycle loop and a second refrigerant cycle loop; one or more direct evaporative indoor air cooler modules are arranged indoors, and a refrigerant storage and transmission unit is connected between each outdoor composite refrigeration module and the corresponding indoor air cooler module to form a closed cycle system through a liquid collecting pipe, a liquid supply main pipe and a return air main pipe. According to the combined refrigeration and multi-connected air conditioning system, the number of the indoor and outdoor modules is set according to the design heating loads of air conditioning objects, refrigerating capacity is precisely regulated, the thermal control demands of various all-weather running data rooms and electronic devices are met, and natural cold sources in days and nights, transition seasons and winters can be used to the maximum extent to realize energy conservation and emission reduction of the air conditioning system.

The invention provides a renewable energy coupled energy storage and temperature regulation wall body system and a using method thereof. The renewable energy coupled energy storage and temperature regulation wall body system is characterized by comprising a temperature regulation wall body, a solar energy device and a shallow soil heat exchange tube; the solar energy device is arranged on a roof of a room; the shallow soil heat exchange tube is buried in the ground; the temperature regulation wall body is connected with the solar energy device and the shallow soil heat exchange tube; one end of the shallow soil heat exchange tube is connected with a water supply pipeline three-way reversing valve, a heat exchange tube water pump and a heat exchange tube flow meter; the other end of the shallow soil heat exchange tube is connected with a water return pipeline three-way reversing valve through a pipeline; the temperature regulation wall body comprises an inner wall plastering layer, a phase change energy storage plate, binding mortar, an inner wall body and an outer wall plastering layer in turn along the direction from interior to exterior; small pipe diameter of coiled pipes are uniformly embedded in the phase change energy storage plate along the direction of the height of the wall body; a water inlet end and a water outlet end of the small pipe diameter of coiled pipes re located at the bottom of the temperature regulation wall body. The using method is divided into three working condition modes of the winter working condition mode, the summer working condition mode and the transition season working condition mode.

The invention relates to an all-year cold supply chiller with natural cooling and cold-accumulation functions. A compressor, an air connecting pipe, a condenser, a liquid connecting pipe, a throttling gear and an evaporator form a steam compression type refrigeration circulation loop; by opening a heat pipe air valve on a heat pipe branch, a heat pipe liquid valve connected in parallel with the throttling gear and an evaporator liquid valve on the evaporator, the evaporator, the air connecting pipe, the condenser and the liquid connecting pipe are connected in sequence to form a cooling medium natural circulation loop; and by opening the heat pipe air valve, the heat pipe liquid valve and a cold-accumulation liquid valve, the air connecting pipe, the condenser, the liquid connecting pipe and a cold-accumulation trough are connected in sequence to form a cold medium cold-accumulation natural circulation loop. The all-year cold supply chiller adopts a split structure, keeps the function of making air conditioning cold water in summer, can sufficiently utilize the natural cold energy of outdoor air to make cold water and accumulate cold in transition seasons and winter, provides cold water for all-year cold supply areas, such as middle apical areas of buildings and highly heating areas, and has the remarkable advantages of simple structure, high efficiency and energy saving.

The invention relates to an air and air energy recovery and ventilation device with defrosting and bypass air supplying functions, which belongs to an air and air energy recovery and ventilation device and aims at solving the problem that load in a cold energy eliminating chamber applying outdoor fresh air can not be utilized by the traditional air and air energy recovery and ventilation device in a transition season. The air and air energy recovery and ventilation device also comprises a bypass air supplying valve, wherein a fifth air passage hole is communicated with a bypass air supplying passage, one end of a baffle plate is arranged on the inner side wall of a casing and the other end is arranged on a heat exchange frame, a second baffle plate is arranged at the fifth air passage hole and is articulated with the heat exchange frame through a second hinge, one end of a second connecting rod is articulated with the second baffle plate and the other end is articulated with a second sliding block which is connected with an output shaft of a second motor in a transmission way, the second motor is fixedly arranged on the bottom end face of the baffle plate, and a power supply controller is connected with the second motor through a lead. The invention is used for recovering indoor heat and cold energy.

The invention relates to an energy-saving operating mode for recovering heat of a central air-conditioner and supplying domestic hot water. The system for recovering heat of the central air-conditioner and supplying domestic hot water comprises a central controller automatic control system, a cold water unit, a cooling tower, a domestic hot water charging system, a heat recovery unit system and a constant-temperature hot water supply system. The system for recovering heat of the central air-conditioner and supplying domestic hot water has the following advantages that: (1) the system can be used for producing domestic hot water by two operating ways according to seasons: in spring and autumn transition season, the heat recovery system can be used for producing domestic hot water continuously by utilizing the recovered heat and also producing basically same amount of coldness to charge the original chilled water system simultaneously during operation, while the operation of other refrigerating units can be stopped or reduced; in summer, the heat recovery system and other cold water units operate simultaneously, and the cooling water of other units is utilized for pre-heating insulating water tanks to charge water; (2) two insulating water tanks are arranged to charge, heat and supply water alternatively, thus a set of complete hot water heating and supplying system is formed, and constant-temperature domestic hot water can be supplied stably; and (3) the system has remarkable economical efficiency.

The invention discloses a control method of a combined type air-conditioning system with a natural cooling function. The control method of the combined type air-conditioning system with the natural cooling function is characterized in that the system comprises a compressor module, an air-cooling heat exchange module, a multifunctional liquid storage device, a liquid pump, an air treatment module and control valves, wherein the air-cooling heat exchange module is composed of a heat exchanger assembly and a cooling fan; and the control method comprises the step that the three different work modes including a compression refrigeration work mode, a compression refrigeration and natural cooling coordinated operation combined refrigeration work mode and the natural cooling work mode are achieved by operating the control valves to change the flowing path of refrigeration media. According to the control method of the combined type air-conditioning system with the natural cooling function, fuzzy control is used for adjusting the refrigeration capacity, natural cooling is used for replacing compression refrigeration in low-temperature or transition seasons, natural cold resources are efficiently utilized, the control method is particularly suitable for control over the work environments of data centers, high-performance computers, communication base stations and power electronic equipment, and the energy consumption and operating cost of the air-conditioning system are greatly reduced.

The invention provides a floor type direct blowing fresh air ventilator. The fresh air ventilator comprises a cabinet body, an air-inlet section, an exchange section and an air-outlet section. The air-inlet section is arranged at the lower portion of the cabinet body and comprises a fresh air inlet, a filtering device and an indoor exhaust air inlet, the fresh air inlet is arranged at the right lower portion of the rear end surface of the cabinet body, the filtering device is installed in the middle of the lower part of the cabinet body, and the indoor exhaust air inlet is arranged at the lower portion of the left end surface of the cabinet body; the exchange section is positioned in the middle inside the cabinet body and comprises a heat exchanger and a draught fan, the draught fan is installed at the right side inside the cabinet body, and the heat exchanger is arranged at the left side of the draught fan; the air-outlet section is positioned on the upper portion inside the cabinet body and comprises an air supply outlet and an efficient filter screen, and the air supply outlet is arranged at the upper portion of the front end surface of the cabinet body. According to the floor type direct blowing fresh air ventilator, a direct blowing structure and a four-level filtering and purification method are adopted, mounting is simple and convenient, the noise is low, the multi-angle air-out and efficient adsorption of harmful gases can be achieved, the fresh air ventilator is applicable in transition seasons, the adjustment is intelligent, and energy consumption is reduced.

The invention discloses a data center CCHP energy supply system and method utilizing a cold source. The energy supply system comprises a data center connected with a power grid, a prime motor connected with a natural gas pipeline network, a waste heat type lithium bromide air conditioner unit connected with the prime motor, a direct-combustion type lithium bromide air conditioner unit connected with the natural gas pipeline network, a low-temperature coiler and an outdoor cold source utilizing device. The all-year cold and electricity load of the data center can be achieved, a power generating set is started all year around, and the electric power supply of core equipment of the data center can be ensured; the cold load in summer and transition seasons of the data center is mainly supplied through the system waste heat type lithium bromide air conditioner unit, the cold load in winter is supplied through an outdoor cold source cold supply subsystem, and a combined cooling, heating and power supply system can recycle waste heat to supply heat to surrounding buildings or provide domestic hot water. According to the data center CCHP energy supply system and method, gradient utilization of energy is achieved, reliability of the energy supply system of the data center is improved, the dependency on the power grid is reduced, the national requirement for establishing the environment-friendly data center is met, and the benefits of energy saving and emission reducing are obvious.

The invention discloses a year-round air conditioning ventilation coupling system and method. The year-round air conditioning ventilation coupling system comprises a cooling module, a heating module and a mechanical ventilation module. According to the coupling system, an upper limit switching temperature and a lower limit switching temperature are seat. When the external temperature is higher than the upper limit switching temperature, the cooling module is executed. When the external temperature is lower than the lower limit switching temperature, the heating module is executed. When the external temperature lies between the upper limit switching temperature and the lower limit switching temperature, the mechanical ventilation module is executed. For a designed object, the year-round air conditioning ventilation coupling system and method can use natural energy sources to supply cold to a room in the transition season or even in winter so as to realize switching between the transition season and the winter-summer air-conditioning season, and therefore, the operation cost of a cold water unit and the like can be saved, and the air quality can be improved greatly by using a summer air duct system to filter fresh air by a filter in an air conditioning box, thereby fully reducing the year-around air conditioning energy consumption.

The invention relates to a water chilling unit. The water chilling unit comprises a refrigerating medium major loop, a freezing medium loop, a refrigerating medium bypass, a control module, and at least one transition season mode. A dry cooler, a refrigerating medium absorbing heat exchanger, a first booster pump, a control valve and the like are connected through a refrigerating medium pipeline in series to form the refrigerating medium major loop. A compressor, an evaporimeter, an expanding valve, a condenser and the like are connected through a freezing medium pipeline in series to form the freezing medium loop. The refrigerating medium bypass which is connected with the refrigerating medium major loop is provided with a second booster pump. The control module controls operation of the water chilling unit. In the transition season mode, the freezing medium loop runs, the refrigerating medium bypass runs, one part of refrigerating medium flowing from the refrigerating medium absorbing heat exchanger flows through the refrigerating medium bypass and then is mixed with the other part of the refrigerating medium. The mixture flows through the dry cooler and the evaporimeter, and returns to the refrigerating medium absorbing heat exchanger. The water chilling unit has the advantages of taking full advantage of outdoor environment as a cold source, reducing output of the compressor, having good energy-saving effect, and meeting requirements of perennial refrigeration.

The invention discloses a fuel cell tramcar heat comprehensive utilization method and a fuel cell tramcar heat comprehensive utilization device, belongs to the technical field of fuel cell application, and solves the problem of fuel cell tramcar heat comprehensive utilization. A cooling fluid outlet pipeline of a fuel cell is connected with a cooling circulating pump; a cooling circulating pump outlet pipeline is connected with a cooling fluid inlet of a radiator group; the cooling fluid outlet of the radiator group is connected with a cooling fluid inlet of the fuel cell; a fresh air preheater is arranged between a fresh air filter and an air return duct; a heating radiator is arranged in a carriage; a main radiator is arranged on the roof of a tramcar; the heating radiator and the fresh air preheater supply heat for the carriage in winter, and the remaining waste heat of the fuel cell is born by the main radiator; an exhaust duct radiator is arranged in the carriage, waste exhaust is taken as a cold source in summer, and the remaining waste heat of the fuel cell is born by the main radiator; under the working conditions in spring and autumn transition seasons, the main radiator bears all remaining waste heat release of the fuel cell. The fuel cell tramcar heat comprehensive utilization method and the fuel cell tramcar heat comprehensive utilization device are mainly used for the fuel cell tramcar heat comprehensive utilization.

The invention relates to a refrigeration, supply heat and hot water system capable of performing solar evaporative cooling and capillary radiation. The refrigeration, supply heat and hot water system is characterized in that a circulation water box in an evaporative cooling system is connected with a water pouring device through a circulation water pump, and the water inlet and water outlet of the circulation water box are respectively connected with the water outlet of a first water collector and the water inlet of a first water knockout drum; the water inlet of the first water collector is respectively connected with the water outlet of an air cooler positioned in an evaporative cooling system and the water outlet of a second water collector, the water outlet of the first water knockout drum is respectively connected with the water inlet of the air cooler and the water inlet of a second water knockout drum, and the water outlet of the second water knockout drum and the water inlet of the second water collector are respectively connected with the water inlet end and water outlet end of a capillary radiation tail end in a room; and a fresh air dehumidifier is communicated with the room, a capillary gravity circulation cabinet is arranged in the room, and the fresh air dehumidifier and the capillary gravity circulation cabinet are respectively connected with the water collector. The refrigeration, supply heat and hot water system provided by the invention has the advantages that the structure is simple, the use is convenient, an energy source is saved, and the fresh air requirements of an air conditioner in winter and summer, the domestic hot water requirements of the whole year and the fresh air requirements of transition seasons are met.

The invention discloses a wind-exhaust and heat-recycle air-conditioning system of a multi-stage and all-condition continuous heat pump, which comprises a new wind pipe, a wind exhaust pipe, a first-stage refrigerating system and a second-stage refrigerating system, wherein the first-stage refrigerating system comprises a first-stage condenser, a first-stage compressor and a first-stage main evaporator successively connected in series; the first-stage condenser is arranged in a fresh wind pipe; the first-stage main evaporator is arranged in an exhaust wind pipe; the second-stage refrigeratingsystem comprises a second-stage condenser, a second-stage compressor and a second-stage main evaporator successively connected in series; the second-stage condenser is arranged in the fresh wind pipein the upwind direction of the first-stage condenser; and the second-stage main evaporator is arranged in the exhaust wind pipe in the downwind direction of the first-stage condenser. The air-conditioning system provided by the invention has the advantages that the system can meet the air-conditioning requirements in winter and transition season, does not need to be matched with other air-conditioning equipment, has high heating energy efficiency, does not need to be provided with an auxiliary heat source for defrosting, reduces the energy consumption and simultaneously decreases the power distribution capacity of the air-conditioning system, thereby having good social and economic benefits.

The invention discloses an air source phase-change energy-storing floor air supply air-conditioning system and an energy-storing and energy-releasing method thereof. The output end of an air source cold/hot water unit is connected with the input end of a water pump; the output end of the water pump is connected with the input end of an electric valve; the output end of the electric valve is connected with the cold/hot water input end of an air conditioner tank; the cold/hot water output end of the air conditioner tank is connected with the input end of the air source cold/hot water unit; the first air output end of the air conditioner tank is connected with the air input end of a room through a first pipeline; the air output end of the room is connected with the first air input end of the air conditioner tank through a second pipeline; and the second air input end of the air conditioner is communicated with the atmospheric air. Cold air with a low temperature at night in transition seasons can be stored through the energy-saving characteristic of a phase-change energy-storing material and can be released in the daytime by using the day-night temperature difference in the transition seasons, and the aim of saving energy is fulfilled. Energy can be stored at night and can be released in the daytime by using the peak-valley electrovalence difference in non-transition seasons, so that peak and valley loads are adjusted, and the running economy of equipment is improved.

The invention discloses a compound air conditioning system with a natural cooling function. The system is characterized by comprising a compressor module, an air cooling heat exchange module consisting of a heat exchanger module and a cooling fan, a multifunctional liquid accumulator, a liquid pump, an air treatment module and control valves; and a control valve is operated to change a flow path of a refrigerating medium to realize the following three different working modes: a compression refrigeration working mode, a compound refrigeration working mode of coordinated operation of compression refrigeration and natural cooling and a natural cooling working mode. The system adjusts the refrigerating capacity by using fuzzy control, applies natural cooling to replace compression refrigeration in low-temperature or transition seasons, efficiently uses a natural cold source, is particularly suitable for working environment control of a data center, a high-performance computer, a communication base station and power electronic equipment, and substantially reduces the energy consumption and the operation cost.

The invention belongs to the technical field of evaporative cooling in the energy field and particularly relates to an anti-freezing method for an indirect evaporative water chilling unit capable of operating all year round and a unit. A water inlet pipeline of the indirect evaporative water chilling unit is divided into two branches, one branch is connected with an inlet on the upper portion of a spray tower, a first valve is arranged on the first branch, and the other branch is connected with an air cooler, a water outlet pipeline on an air outlet side of the air cooler is connected with a water tank inlet on the lower portion of the spray tower, and a second valve is arranged on the other branch; a water outlet pipeline at the bottom of the spray tower is divided into two branches, one branch is connected with the air cooler, a self-circulation water pump is arranged on the branch, the other branch is connected with a user end, and a cold water circulation pump is arranged on the other branch; and a fan and an air outlet are arranged at the top inside the spray tower, and an air inlet is arranged on the lower portion of the lateral side. Operation conditions of the indirect evaporative water chilling unit are divided into three kinds in summer, transition seasons and winter, the indirect evaporative water chilling unit can be guaranteed to operate all year round, different modes are operated according to outdoor temperatures, the air cooler and the spray tower are guaranteed not to be damaged in winter, and accordingly, stable and reliable cold sources are provided all year round.

The invention discloses a clean pig farm with a controllable environment and an operation method of the clean pig farm. In the scheme, a pig farm is totally designed to be a full closed structure; the pig farm is provided with a cooling ventilating system and a deodorizing ventilating system; the cooling ventilating system forms negative pressure in the fully closed pig farm, and makes air in the pig farm flow by using the negative pressure suction effect, and humidifies and cools the pig farm by a wet curtain; the deodorizing ventilating system ventilates the pig farm in longitudinal direction from top to bottom, and forms a certain face wind speed in the pig farm; moreover, odor is controlled in a bowl movement zone by using inside and outside air pressure; meanwhile, an exhaust air flow forms in the bowl movement zone, so that discharge the odor in the air; besides, the seasonal running of the pig farm in the whole year includes summer, winter and transition season. The pig farm provided by the scheme can effectively keep the indoor odor concentration at the upper limit below of the stipulated concentration in the whole year through cooperating with corresponding running scheme; meanwhile, the indoor temperature is always within the required scale, and thus the incidence of pigs is greatly reduced.

The invention relates to a double-cold source fresh air handling unit, which comprises a fresh air handling unit shell, wherein a compressor, a first condenser, a second condenser, a throttling device, an evaporimeter, an air inlet, a filter, an air outlet, a chilled water supply water return pipe and a surface air cooler are arranged in the fresh air handling unit shell; the compressor, the first condenser, the second condenser, the throttling device and the evaporimeter are connected sequentially through a copper pipe so as to form a cold source system of the fresh air handling unit; and the surface air cooler is connected with an external central air conditioning cold source system through the chilled water supply water return pipe. The double-cold source fresh air handling unit has the advantages that (1) the double-cold source fresh air handling unit is provided with the independent cold source system, in a transition season, a central air conditioning cold source stops working, and when an air conditioning ventilation system fresh air is operated in an energy-saving way, a self cold source can be applied to carry out dehumidification on fresh air, so that the phenomena of indoor moisture and mustiness are avoided; and (2) when the fresh air handling unit is used, the fed fresh air supplied in the transition season has moderate temperature, and the comfort of indoor temperature in the transition season is ensured.