CN-122015210-A - Air conditioning unit utilizing return air reheating and control method

CN122015210ACN 122015210 ACN122015210 ACN 122015210ACN-122015210-A

Abstract

The invention relates to the field of air conditioning, and discloses an air conditioning unit and a control method utilizing return air reheating, wherein the air conditioning unit comprises an air delivery and distribution and treatment system, the air delivery and distribution system comprises a return air pipe, a first return air inlet is arranged on the return air pipe, the first return air inlet is arranged in an indoor space, the fresh air inlet is arranged outdoors and communicated with a first air mixing box through the air delivery pipe, the fresh air inlet and the return air pipe are connected to the first air mixing box, the first air mixing box is communicated with a surface cooler, the surface cooler, a direct expansion type air cooling evaporator, a second air mixing box and an air feeder are connected through the air delivery pipe, the air delivery pipe is provided with the air delivery inlet and is arranged in the indoor space, a bypass pipe is arranged on the air delivery pipe between the surface cooler and the direct expansion type air cooling evaporator and is connected with the second air mixing box, and an electric air quantity adjusting valve is arranged on the return air pipe and used for adjusting the proportion of air entering the first air mixing box through the fresh air inlet and the first air mixing box. According to the invention, the ratio of the air return quantity of the air return opening and the air return pipe to the fresh air quantity passing through the fresh air opening is kept at the set value, and the air return is utilized to the greatest extent on the premise of meeting the indoor CO 2 concentration requirement, so that the energy consumption of an air conditioning system is reduced.

Inventors

LU HUAWEI
ZHU YUE
CHEN YUYUAN
WANG HANXU
FENG TENG
LI KUANGYI
YU YUANBO
LEI CHONG
LIU JUN
CAI CHONGQING
WANG XIAOFEI
HUANG CHENYU
YANG LIZHEN
XIA JIHAO
CHENG HAO

Assignees

中国铁建股份有限公司
中铁第四勘察设计院集团有限公司

Dates

Publication Date: 20260512
Application Date: 20260206

Claims (10)

1. The utility model provides an utilize air conditioning unit of return air reheat, includes built-in refrigeration cycle subassembly, refrigeration cycle subassembly includes compressor, expansion valve, evaporimeter, condenser, and wherein the evaporimeter includes directly expands forced air cooling evaporimeter, water-cooling evaporimeter, and two sets of evaporimeters establish ties, and the cooling water is provided by external cooling tower and circulating pump, and each subassembly passes through refrigerant pipeline connection, its characterized in that still includes air delivery and processing system and reheat system, air delivery and processing system includes: The air conditioner comprises an air return pipe, a surface cooler, a direct expansion type air cooling evaporator, a second air mixing box, an air feeder, a bypass pipe, a first air return pipe, a second air mixing box and a second air return pipe, wherein the first air return pipe is arranged on the air return pipe and is arranged in an indoor space; The reheating system comprises a second air return port, a reheating pipe, a reheating fan, a fourth electric air quantity switch valve and a fourth air speed sensor, wherein the second air return port is arranged indoors and connected to the reheating pipe, the two ends of the reheating fan and the four electric air quantity switch valve are connected with the reheating pipe, the reheating pipe is communicated with the second air mixing box, and the fourth air speed sensor is arranged on the reheating pipe.
2. The air conditioning unit utilizing return air reheating method according to claim 1, wherein the electric air quantity regulating valve is arranged on a return air pipe and used for regulating air quantity of the return air pipe, regulating air proportion entering the first air mixing box through the fresh air inlet and the first return air inlet, the first electric air quantity switching valve and the second electric air quantity switching valve are arranged on the air supply pipe and positioned on two sides of the direct expansion type air cooling evaporator, the third electric air quantity switching valve is arranged on a bypass pipe, the first electric air quantity switching valve and the second electric air quantity switching valve are closed, when the third electric air quantity switching valve is opened, air is dehumidified only through the surface air cooler, when the first electric air quantity switching valve and the second electric air quantity switching valve are opened, and when the third electric air quantity switching valve is closed, the air is cooled and dehumidified through the surface air cooler and the direct expansion type air cooling evaporator.
3. An air conditioning unit utilizing return air reheating according to claim 1 or 2, wherein a plurality of temperature and humidity sensors and wind speed sensors are installed on the air duct for monitoring temperature, humidity and wind quantity of air, and a CO 2 sensor is installed at an indoor middle position.
4. The air conditioning unit utilizing return air reheating method according to claim 3, wherein the second air speed sensor and the first temperature and humidity sensor are sequentially installed on the return air pipe and close to the first return air inlet, the first air speed sensor and the second temperature and humidity sensor are sequentially installed on the air supply pipe and close to the air supply inlet, the third temperature and humidity sensor is installed at the fresh air inlet, the third air speed sensor is installed on the air supply pipe and close to the air supply inlet, the fourth temperature and humidity sensor is installed on the air supply pipe and close to the surface air cooler, and the fifth temperature and humidity sensor is installed on the air supply pipe and is located between the direct expansion type air cooling evaporator and the second air mixing box.
5. The air conditioning unit utilizing return air reheat of claim 4, further comprising a chilled water and cooling water distribution system including a chilled water circulation pump, an electric water valve, a first water temperature sensor, a second water temperature sensor, the above components being connected by a chilled water line, wherein the first water temperature sensor, the second water temperature sensor are mounted on the chilled water line between the water cooled evaporator and the surface chiller, the cooling water being provided by an external cooling tower and circulation pump, the unit reserving a cooling water interface.
6. The air conditioning unit utilizing return air reheating of claim 5, further comprising a control cabinet, wherein the control cabinet comprises a power air switch, a signal acquisition module, a PLC, a chilled water circulation pump inverter, a blower inverter, a reheat fan inverter, and a control module, wherein the control module comprises an electric air volume adjustment/switch valve control module and a compressor control module.
7. The control method of the air conditioning unit utilizing return air reheating, which adopts the air conditioning unit utilizing return air reheating as claimed in claim 6, is characterized by comprising a blower and an electric air quantity regulating valve control strategy: (1) The signal acquisition module in the control cabinet receives indoor CO 2 sensor signals, the PLC compares and analyzes indoor CO 2 concentration set values and indoor CO 2 sensor signals, and outputs control signals, the output frequency of the blower frequency converter is dynamically adjusted, the air supply quantity is controlled, when the indoor CO 2 concentration is consistent with the set values, the blower is maintained to operate at the frequency, and the operating frequency of the blower is not lower than 35 Hz; (2) The signal acquisition module in the control cabinet receives signals of the second wind speed sensor and the third wind speed sensor, the PLC compares and compares the set value and the actual measured value of the proportion of return air and fresh air quantity, and outputs a control signal, and the electric air quantity valve control module is utilized to adjust the opening degree of the electric air quantity regulating valve, so that the ratio of the return air quantity passing through the return air inlet and the return air pipe to the fresh air quantity passing through the fresh air inlet is kept at the set value, the return air is utilized to the greatest extent on the premise of meeting the indoor CO 2 concentration requirement, and the energy consumption of an air conditioning system is reduced.
8. The control method of the air conditioning unit utilizing return air reheating is characterized by comprising the steps of adjusting an air cooling and dehumidifying operation strategy after the blower and the electric air quantity regulating valve are stable in operation according to claim 7, and ensuring that the relative humidity of the return air monitored by the first temperature and humidity sensor is maintained at a set value: (1) The first temperature and humidity sensor is compared with a relative humidity set value, when the relative humidity of return air is more than or equal to the set value, a first electric air volume switch valve and a second electric air volume switch valve are opened, a third electric air volume switch valve is closed, fresh air and return air mixed in a first air mixing box are subjected to two-stage cooling dehumidification through a surface cooler with chilled water supply and return water temperature of 7-12 ℃, and a direct expansion air cooling evaporator; (2) The electric air quantity switch valve is opened and closed, the cooling and dehumidifying effects of air supply are affected, and the relative humidity of return air monitored by the first temperature and humidity sensor is further changed, so that circulation is realized.
9. The control method of the air conditioning unit utilizing return air reheating is characterized by comprising the steps of synchronously adjusting a reheating fan operation control strategy when the air cooling and dehumidifying operation strategy is adjusted according to claim 8, and ensuring that the air supply temperature monitored by the second temperature and humidity sensor is maintained at a set value: (1) In the initial state, the fifth temperature and humidity sensor or the fourth temperature and humidity sensor is used as an initial input value to be compared with a set value, and when the initial input value is more than or equal to the set value, the reheat fan and the fourth electric air quantity switching valve are closed; (2) After the initial state is adjusted, comparing the air supply temperature monitored by the second temperature and humidity sensor with a set value, and when the air supply temperature monitored by the second temperature and humidity sensor is smaller than the set value, starting a reheat fan and a fourth electric air quantity switching valve, circularly adjusting the operation frequency of the reheat fan, mixing and heating indoor high-temperature air and air supply in a second air mixing box, and then feeding the air into the room; (3) The reheat fan is started and stopped and the running frequency is changed, so that the air supply temperature monitored by the second temperature and humidity sensor is influenced, and the cycle is performed.
10. The method for controlling a re-heating air conditioning unit according to claim 7, wherein the volume ratio of the return air to the fresh air is set to 9:1.

Description

Air conditioning unit utilizing return air reheating and control method Technical Field The invention relates to the field of air conditioning, in particular to an integrated air conditioning unit and a control method thereof, which are suitable for deep dehumidification and return air reheating of high-humidity spaces such as underground traffic buildings, underground commercial complexes and the like. Background The humidity control of the high humidity environment usually adopts a surface cooler to cool and dehumidify, which is a common technical scheme. When a surface cooler is adopted for dehumidification in a high-humidity environment such as an underground space, the purpose of cooling and dehumidifying air is achieved by reducing the temperature of chilled water entering a coil of the surface cooler (such as cooling and dehumidifying air) generally, and when the temperature of air entering a room is low (such as the supply temperature of 15 ℃) the problem of condensation and the like can be caused at the position of a supply port, in order to avoid the problem, the air entering the room is generally required to be heated (such as 20 ℃) by electric thermal resistance or high-temperature hot water before the low-temperature air is sent into the room. Obviously, the treatment mode that the air is heated after the temperature and the humidity of the air are reduced by the chilled water can cause larger energy waste. Disclosure of Invention The invention aims to provide an integrated air conditioning unit and a control method, wherein the dehumidifying amount is adjustable, no electric thermal resistance or high-temperature hot water reheating is realized, the integrated air conditioning unit is suitable for high-humidity environments such as underground space and the like, the reheating air pipe and a fan are used for improving the air supply temperature, and dew condensation at an air supply port is avoided. The air conditioning unit adopts a reheating mode of setting a reheating air pipe and a reheating fan and mixing indoor high-temperature air (about 25 ℃) with cooled and dehumidified air, only consumes a small amount of fan power consumption, and avoids a great amount of energy waste caused by traditional reheating by adopting electric thermal resistance or high-temperature hot water. In order to further achieve the above purpose, the present invention adopts the following technical scheme: The utility model provides an utilize air conditioning unit of return air reheat, includes built-in refrigeration cycle subassembly, refrigeration cycle subassembly includes compressor, expansion valve, evaporimeter, condenser, and wherein the evaporimeter includes directly expands forced air cooling evaporimeter, water-cooling evaporimeter, and two sets of evaporimeters establish ties, and the cooling water is provided by external cooling tower and circulating pump, and each subassembly passes through refrigerant pipeline connection, still includes air delivery and processing system and reheat system, air delivery and processing system includes: The air conditioner comprises an air return pipe, a surface cooler, a direct expansion type air cooling evaporator, a second air mixing box, an air feeder, a bypass pipe, a first air return pipe, a second air mixing box and a second air return pipe, wherein the first air return pipe is arranged on the air return pipe and is arranged in an indoor space; The reheating system comprises a second air return port, a reheating pipe, a reheating fan, a fourth electric air quantity switch valve and a fourth air speed sensor, wherein the second air return port is arranged indoors and connected to the reheating pipe, the two ends of the reheating fan and the four electric air quantity switch valve are connected with the reheating pipe, the reheating pipe is communicated with the second air mixing box, and the fourth air speed sensor is arranged on the reheating pipe. The electric air volume regulating valve is arranged on the return air pipe and used for regulating the air volume of the return air pipe and regulating the proportion of air entering the first air mixing box through the fresh air inlet and the first return air inlet, the first electric air volume switching valve and the second electric air volume switching valve are arranged on the air supply pipe and are positioned on two sides of the direct expansion type air cooling evaporator, the third electric air volume switching valve is arranged on the bypass pipe, the first electric air volume switching valve and the second electric air volume switching valve are closed, when the third electric air volume switching valve is opened, the air is dehumidified only through the surface air cooler, when the first electric air volume switching valve and the second electric air volume switching valve are opened, and when the third electric air volume switching valve is closed, the air is cooled and dehumidified through the surface a