High-precision constant-temperature and constant-humidity test room
By using fresh air pretreatment units, fresh air handling units, and a main temperature and humidity treatment system, combined with equipment such as a 4-stage electric heating module and high-efficiency filters, the problem of uneven temperature distribution in the constant temperature and humidity test chamber has been solved, achieving high-precision temperature and humidity control and stability, and making it suitable for various climatic conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-23
- Publication Date
- 2026-05-15
AI Technical Summary
The existing constant temperature and humidity test chambers have the problem of uneven temperature distribution inside the drying chamber, which affects the progress of experiments.
It adopts a fresh air pretreatment unit, a fresh air handling unit, and a temperature and humidity main treatment system, combined with a 4-stage electric heating module and high-efficiency filters, dehumidifiers, humidifiers, coolers, and other equipment. Through fresh air pretreatment and fresh air treatment, it achieves precise control of indoor temperature and humidity.
It improves the control accuracy and stability of indoor temperature and humidity, expands the operating range of temperature and humidity, and is suitable for different climatic conditions, especially the extremely cold weather in the north.
Smart Images
Figure CN224236869U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of laboratory technology, specifically a high-precision constant temperature and humidity laboratory. Background Technology
[0002] The main purpose of a constant temperature and humidity test chamber is to simulate various environmental conditions, such as temperature, humidity, and pressure, to test the performance and reliability of products or materials.
[0003] A Chinese patent with publication number CN204648556U discloses a constant temperature and humidity test chamber, including a constant temperature and humidity room, a blower unit, and a control box. The constant temperature and humidity room has an air duct at its upper part, with evenly spaced ventilation openings at the lower end of the duct. A first temperature and humidity sensor is located near the upper part of the duct, and a second temperature and humidity sensor is located in the middle. The blower unit has a circulating fan at its upper part, with its outlet connected to the air duct. An air inlet at the lower part of the blower unit connects to the constant temperature and humidity room. The blower unit contains an electric heater, a dehumidifying valve, a dehumidifying surface cooler, and a humidifier. The outer walls and top layer of the constant temperature and humidity room and the blower unit are insulated. The control box has control lines connecting the first and second temperature and humidity sensors, the circulating fan, the electric heater, the dehumidifying valve, the dehumidifying surface cooler, and the humidifier. The dehumidifying surface cooler is connected to a chiller unit.
[0004] The aforementioned patent has many advantages, but also some problems: the temperature distribution inside the drying chamber is uneven, which affects the progress of the experiment. Summary of the Invention
[0005] This invention provides a high-precision constant temperature and humidity test chamber, which solves the problems mentioned in the background art by setting up a fresh air pretreatment unit, a fresh air handling unit and a temperature and humidity main treatment system.
[0006] This utility model provides the following technical solution: a high-precision constant temperature and humidity test chamber, including a climate chamber and a machine room. A fresh air inlet is provided on one side of the machine room. A fresh air pretreatment unit is provided in the machine room and connected to the fresh air inlet. The fresh air pretreatment unit is used to send the pretreated fresh air into the temperature and humidity main treatment system in the climate chamber. The output end of the fresh air pretreatment unit is connected to the top of the temperature and humidity main treatment system in the climate chamber. The temperature and humidity main treatment system is provided in the climate chamber and is used to control the temperature and humidity inside the climate chamber.
[0007] A buffer room is provided on one side of the climate chamber. A medium-efficiency exhaust box is provided on the top side of the climate chamber near the buffer room. A ventilation louver connected to the machine room is provided on the bottom side of the buffer room. An anti-backflow exhaust cabinet is provided in the machine room. An exhaust hood is provided at the input end of the anti-backflow exhaust cabinet. An exhaust outlet installed on the machine room is connected to the output end of the anti-backflow exhaust cabinet.
[0008] As an optional solution for the high-precision constant temperature and humidity test chamber described in this utility model, the main temperature and humidity processing system includes a four-stage electric heating module, comprising a first-stage electric heating module, a second-stage electric heating module, a third-stage electric heating module, and a fourth-stage electric heating module. The first-stage electric heating module is installed in the fresh air pretreatment unit, the second-stage electric heating module is installed at the air inlet of the fresh air pretreatment unit, the third-stage electric heating module is installed at the air outlet of the fresh air pretreatment unit, and the fourth-stage electric heating module is installed within the main temperature and humidity processing system. The fresh air pretreatment unit includes an air filter, an electric heater, and a control system. Its main function is to heat the outdoor cold air to about 5°C to prevent the indoor air ducts from freezing and cracking, while simultaneously raising the air temperature and reducing the heating load on the fresh air pretreatment unit.
[0009] As an optional embodiment of the high-precision constant temperature and humidity test chamber described in this utility model, the fresh air handling unit includes an air filter, a dehumidifier, a humidifier, a heater, a cooler, and a first control system. The air filter is a high-efficiency filter used to filter out dust and particulate matter in the fresh air, ensuring the cleanliness of the fresh air entering the climate chamber. The dehumidifier uses condensation dehumidification technology to remove moisture from the fresh air and control its dryness. The humidifier uses an ultrasonic humidifier to humidify the fresh air. The heater uses electric heating to preheat the fresh air. The cooler uses chilled water cooling to cool the fresh air. The first control system uses a high-performance embedded controller to monitor the temperature, humidity, and cleanliness of the fresh air in real time and adjust the operating status of the air filter, dehumidifier, heater, and cooler as needed.
[0010] As an optional solution for the high-precision constant temperature and humidity test chamber of this utility model, the top of the climate chamber is fully covered with perforated ceiling panels for air supply, the output end of the fresh air handling unit is connected to the main temperature and humidity treatment system, and a turbulence fan is installed above the perforated ceiling panels for air supply. The turbulence fan improves the uniformity of air supply through mixing.
[0011] As an optional solution for the high-precision constant temperature and humidity test chamber of this utility model, the top of the climate chamber is provided with a hanging component, and the hanging component is provided with four sets of slots. The four sets of slots are used to connect the air supply ceiling perforated plate, so that each set of air supply ceiling perforated plate fits tightly without gaps, and the air supply ceiling perforated plate is fixed to the hanging component by screws.
[0012] As an optional solution for the high-precision constant temperature and humidity test chamber described in this utility model, the main temperature and humidity processing system also includes a constant temperature and humidity air conditioner. The constant temperature and humidity air conditioner is installed in the climate chamber and is equipped with four ultrasonic humidifiers to improve humidity control accuracy and increase the temperature and humidity control range. The constant temperature and humidity air conditioner is also equipped with one rotary dehumidifier and one refrigeration dehumidifier. By combining the rotary dehumidifier and the refrigeration dehumidifier, the temperature and humidity control range is improved.
[0013] As an optional solution for the high-precision constant temperature and humidity test chamber described in this utility model, the machine room is also equipped with a chilled water air conditioning shared unit connected to the fresh air pretreatment unit and the main temperature and humidity treatment system. The chilled water air conditioning shared unit is used to provide chilled water for fresh air pretreatment and temperature control of the climate chamber. The chilled water air conditioning shared unit includes a condenser, a condenser fan, a water tank, a water pump, and a control system. The chilled water air conditioning shared unit is used to generate chilled water, the water pump is used to circulate and transport the chilled water, the cooling tower is used to dissipate heat to ensure that the temperature of the chilled water is suitable, and the heat exchanger is used to transfer the cooling capacity of the chilled water to the fresh air pretreatment unit and the main temperature and humidity treatment system of the climate chamber. The second control system is used to coordinate the operation of the chilled water unit, the water pump, the cooling tower, and the heat exchanger to achieve precise control of the chilled water.
[0014] As an optional embodiment of the high-precision constant temperature and humidity test chamber described in this utility model, the preheating temperature in the fresh air pretreatment unit is controlled by a temperature control formula, which is as follows:
[0015] Among them, T out For output control signals; K p For proportional gain; K i K is the integral gain; d T is the differential gain; set To set the temperature; T current This is the current temperature.
[0016] As an optional solution for the high-precision constant temperature and humidity test chamber described in this utility model, the humidity in the main temperature and humidity processing system is controlled by a humidity control formula to control the temperature. The specific humidity control formula is as follows:
[0017] Among them, H out For output control signals; K p For proportional gain; K i K is the integral gain; d For differential gain; H set To set the temperature; H current This is the current temperature.
[0018] As an optional solution for the high-precision constant temperature and humidity test chamber described in this utility model, the dehumidification formula used in the dehumidifier of the fresh air pretreatment unit is:
[0019] Where, m w It is the mass of water vapor; P v It is the partial pressure of water vapor; V is the volume of air; R v is the gas constant for water vapor; T is the temperature.
[0020] The heating formula used in the heater of the fresh air pretreatment unit is:
[0021] Where Q is the amount of heating; m is the mass of air; cp is the specific heat capacity of air; and ΔT is the temperature change.
[0022] The present invention has the following beneficial effects: 1. In this high-precision constant temperature and humidity test chamber, by setting up a fresh air pretreatment unit, the outdoor air can be filtered and treated to ensure the air quality entering the climate chamber. At the same time, the fresh air pretreatment unit works in conjunction with the fresh air handling unit and the main temperature and humidity treatment system to facilitate the control of air temperature and humidity, so that the indoor temperature and humidity operating range is wider and the temperature and humidity control accuracy is higher.
[0023] 2. In this high-precision constant temperature and humidity test chamber, the main temperature and humidity processing system is equipped with a four-stage electric heating module. The first-stage electric heating module is installed in the fresh air pretreatment unit, the second-stage electric heating module is installed at the air inlet of the fresh air handling unit, the third-stage electric heating module is installed at the air outlet of the fresh air handling unit, and the fourth-stage electric heating module is installed in the main temperature and humidity processing system. Through the gradual regulation of the four-stage electric heating, the control accuracy of indoor temperature and humidity can be improved, the stability of indoor temperature and humidity operation can be improved, and it can be used in the extremely cold weather of northern winters, increasing its versatility. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the structure of this utility model.
[0025] Figure 2 This is a structural block diagram of the fresh air pretreatment unit of this utility model.
[0026] Figure 3This is a structural block diagram of the chilled water air conditioning shared unit of this utility model.
[0027] Figure 4 This is a schematic diagram of the surface structure of the lifting component of this utility model.
[0028] Figure 5 This is a cross-sectional view of the lifting component of this utility model.
[0029] In the diagram: 1. Machine room; 2. Climate room; 3. Fresh air inlet; 4. Fresh air pretreatment unit; 5. Fresh air handling unit; 6. Main temperature and humidity control system; 7. Buffer room; 8. Medium-efficiency exhaust box; 9. Ventilation louvers; 10. Anti-backflow exhaust cabinet; 11. Exhaust hood; 12. Exhaust outlet; 13. Supply air ceiling perforated plate; 14. Turbulence fan; 15. Hanging component; 16. Card slot; 17. Shared chilled water air conditioning unit. Detailed Implementation
[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0031] Example 1, please refer to Figures 1-5 A high-precision constant temperature and humidity test chamber includes a climate chamber 2 and a machine room 1. A fresh air inlet 3 is provided on one side of the machine room 1. A fresh air pretreatment unit 4, connected to the fresh air inlet 3, is installed inside the machine room 1. The fresh air pretreatment unit 4 is used to deliver pretreated fresh air into the main temperature and humidity treatment system 6 inside the climate chamber 2. The output end of the fresh air pretreatment unit 4 is connected to the top of the main temperature and humidity treatment system 6. The main temperature and humidity treatment system 6 is installed inside the climate chamber 2. System 6 is used to control the temperature and humidity inside the climate chamber 2; a buffer chamber 7 is provided on one side of the climate chamber 2, a medium-efficiency exhaust box 8 is provided on the top side of the climate chamber 2 near the buffer chamber 7, a ventilation louver 9 connected to the machine room 1 is provided on the bottom side of the buffer chamber 7, an anti-backflow exhaust cabinet 10 is provided in the machine room 1, an exhaust hood 11 is provided at the input end of the anti-backflow exhaust cabinet 10, and an exhaust outlet 12 installed on the machine room 1 is connected to the output end of the anti-backflow exhaust cabinet 10.
[0032] refer to Figures 1 to 5The main temperature and humidity processing system 6 includes a four-stage electric heating module, comprising a first-stage, a second-stage, a third-stage, and a fourth-stage electric heating module. The first-stage electric heating module is installed in the fresh air pretreatment unit 4, the second-stage electric heating module is installed at the air inlet of the fresh air handling unit 5, the third-stage electric heating module is installed at the air outlet of the fresh air handling unit 5, and the fourth-stage electric heating module is installed within the main temperature and humidity processing system 6. The fresh air pretreatment unit 4 includes an air filter, an electric heater, and a control system. Its main function is to heat the outdoor cold air to approximately 5°C to prevent the indoor air ducts from freezing and cracking, while simultaneously raising the air temperature initially and reducing the heating load on the fresh air handling unit 5.
[0033] refer to Figures 1 to 5 The fresh air handling unit 5 includes an air filter, a dehumidifier, a humidifier, a heater, a cooler, and a first control system. The air filter is a high-efficiency filter used to filter out dust and particulate matter in the fresh air, ensuring that the fresh air entering the climate chamber 2 is clean. The dehumidifier uses condensation dehumidification technology to remove moisture from the fresh air and control its dryness. The humidifier is an ultrasonic humidifier used to humidify the fresh air. The heater uses electric heating to preheat the fresh air. The cooler uses chilled water cooling to cool the fresh air. The first control system uses a high-performance embedded controller to monitor the temperature, humidity, and cleanliness of the fresh air in real time and adjust the operating status of the air filter, dehumidifier, heater, and cooler as needed.
[0034] refer to Figures 1 to 5 The climate chamber 2 has its top covered with perforated ceiling panels 13 for air supply. The output of the fresh air handling unit 5 is connected to the main temperature and humidity control system 6. A turbulence fan 14 is installed above the perforated ceiling panels 13, which improves the uniformity of air supply through mixing. A hanging bracket 15 is provided on the top of the climate chamber 2. The hanging bracket 15 has four sets of slots 16 for connecting the perforated ceiling panels 13, ensuring a tight fit between each set of perforated ceiling panels 13 without gaps. The perforated ceiling panels 13 are fixed to the hanging bracket 15 with screws. The main temperature and humidity processing system 6 further includes a constant temperature and humidity air conditioner, which is installed in the climate chamber 2. The constant temperature and humidity air conditioner is equipped with four ultrasonic humidifiers to improve humidity control accuracy and increase the temperature and humidity control range. The constant temperature and humidity air conditioner is also equipped with one rotary dehumidifier and one refrigeration dehumidifier. The combination of the rotary dehumidifier and the refrigeration dehumidifier improves the temperature and humidity control range.
[0035] refer to Figures 1 to 5The machine room 1 is further equipped with a chilled water air conditioning shared unit 17 connected to the fresh air pretreatment unit 4 and the main temperature and humidity processing system 6. The chilled water air conditioning shared unit 17 provides chilled water for fresh air pretreatment and temperature control in the climate chamber 2. The chilled water air conditioning shared unit 17 includes a condenser, a condenser fan, a water tank, a water pump, and a control system. The chilled water air conditioning shared unit 17 generates chilled water, the water pump circulates the chilled water, the cooling tower dissipates heat to ensure a suitable chilled water temperature, and the heat exchanger transfers the cooling capacity of the chilled water to the fresh air pretreatment unit 4 and the main temperature and humidity processing system 6 in the climate chamber 2. The second control system coordinates the operation of the chiller, water pump, cooling tower, and heat exchanger to achieve precise control of the chilled water. The preheating temperature in the fresh air pretreatment unit 4 is controlled using a temperature control formula, which is as follows:
[0036] Among them, T out For output control signals; K p For proportional gain; K i K is the integral gain; d T is the differential gain; set To set the temperature; T current This is the current temperature.
[0037] refer to Figures 1 to 5 The temperature and humidity main processing system 6 uses a humidity control formula to control the temperature, and the specific humidity control formula is as follows:
[0038] Among them, H out For output control signals; K p For proportional gain; K i K is the integral gain; d For differential gain; H set To set the temperature; H current This is the current temperature.
[0039] As an optional solution for the high-precision constant temperature and humidity test chamber described in this utility model, the dehumidification formula used in the dehumidifier of the fresh air pretreatment unit 4 is as follows:
[0040] Where, m w It is the mass of water vapor; P v It is the partial pressure of water vapor; V is the volume of air; R v is the gas constant for water vapor; T is the temperature.
[0041] The heating formula used in the heater of the fresh air pretreatment unit 4 is as follows:
[0042] Where Q is the heating amount; m is the air mass; c p ΔT is the specific heat capacity of air; ΔT is the temperature change.
[0043] refer to Figures 1 to 5 In this high-precision constant temperature and humidity test chamber, a fresh air pretreatment unit 4 filters outdoor air to ensure the air quality entering the climate chamber 2. Simultaneously, the fresh air pretreatment unit 4 works in conjunction with the fresh air handling unit 5 and the main temperature and humidity control system 6 to facilitate temperature and humidity control, resulting in a wider operating range and higher control accuracy for indoor temperature and humidity. The main temperature and humidity control system 6 is equipped with a four-stage electric heating module. The first stage electric heating module is installed in the fresh air pretreatment unit 4, the second stage at the air inlet of the fresh air handling unit 5, the third stage at the air outlet of the fresh air handling unit 5, and the fourth stage within the main temperature and humidity control system 6. This gradual adjustment through four stages of electric heating improves the control accuracy of indoor temperature and humidity, enhances the stability of indoor temperature and humidity operation, and makes the chamber suitable for extremely cold winters in northern regions, increasing its versatility.
[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0045] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.
Claims
1. A high-precision constant temperature and humidity test chamber, comprising a climate chamber (2) and a machine room (1), characterized in that: A fresh air inlet (3) is provided on one side of the machine room (1). A fresh air pretreatment unit (4) connected to the fresh air inlet (3) is provided in the machine room (1). The fresh air pretreatment unit (4) is used to pretreat the fresh air. A fresh air handling unit (5) connected to the fresh air pretreatment unit (4) is provided in the machine room (1). The fresh air handling unit (5) is used to send the pretreated fresh air into the temperature and humidity main processing system (6) in the climate chamber. The output end of the fresh air handling unit (5) is connected to the top of the temperature and humidity main processing system (6) in the climate chamber (2). The temperature and humidity main processing system (6) is provided in the climate chamber (2). The temperature and humidity main processing system (6) is used to control the temperature and humidity inside the climate chamber (2). A buffer room (7) is provided on one side of the climate chamber (2). A medium-efficiency exhaust box (8) is provided on the top side of the climate chamber (2) near the buffer room (7). A ventilation louver (9) connected to the machine room (1) is provided on the bottom side of the buffer room (7). An anti-backflow exhaust cabinet (10) is provided in the machine room (1). An exhaust hood (11) is provided at the input end of the anti-backflow exhaust cabinet (10). An exhaust outlet (12) installed on the machine room (1) is connected to the output end of the anti-backflow exhaust cabinet (10).
2. The high-precision constant temperature and humidity test chamber according to claim 1, characterized in that: The temperature and humidity main processing system (6) includes a 4-stage electric heating module, which includes a first-stage electric heating module, a second-stage electric heating module, a third-stage electric heating module and a fourth-stage electric heating module. The first-stage electric heating module is installed in the fresh air pretreatment unit (4), the second-stage electric heating module is installed at the air inlet of the fresh air treatment unit (5), the third-stage electric heating module is installed at the air outlet of the fresh air treatment unit (5), and the fourth-stage electric heating module is installed in the temperature and humidity main processing system (6). The fresh air pretreatment unit (4) includes an air filter, an electric heater and a control system. Its main function is to heat the outdoor cold air to about 5°C to prevent the indoor air ducts from freezing and cracking, and at the same time, to initially increase the air temperature and reduce the heating load of the fresh air treatment unit (5).
3. The high-precision constant temperature and humidity test chamber according to claim 2, characterized in that: The fresh air handling unit (5) includes an air filter, a dehumidifier, a humidifier, a heater, a cooler, and a first control system. The air filter is a high-efficiency filter used to filter out dust and particulate matter in the fresh air, ensuring that the fresh air entering the climate chamber (2) is clean. The dehumidifier uses condensation dehumidification technology to remove moisture from the fresh air and control its dryness. The humidifier uses an ultrasonic humidifier to humidify the fresh air. The heater uses electric heating to preheat the fresh air. The cooler uses chilled water cooling to cool the fresh air. The first control system uses a high-performance embedded controller to monitor the temperature, humidity, and cleanliness of the fresh air in real time and adjust the working status of the air filter, dehumidifier, heater, and cooler as needed.
4. The high-precision constant temperature and humidity test chamber according to claim 3, characterized in that: The top of the climate chamber (2) is covered with perforated ceiling panels (13) for air supply. The output end of the fresh air handling unit (5) is connected to the main temperature and humidity handling system (6). A turbulence fan (14) is installed above the perforated ceiling panels (13). The turbulence fan (14) improves the uniformity of air supply through mixing.
5. The high-precision constant temperature and humidity test chamber according to claim 4, characterized in that: The climate chamber (2) is provided with a hanging member (15) on the top. The hanging member (15) is provided with four sets of slots (16). The four sets of slots (16) are used to connect the air supply ceiling perforated plate (13). The air supply ceiling perforated plate (13) is fixed to the hanging member (15) by screws.
6. The high-precision constant temperature and humidity test chamber according to claim 5, characterized in that: The main temperature and humidity processing system (6) also includes a constant temperature and humidity air conditioner, which is installed in the climate chamber (2). The constant temperature and humidity air conditioner is equipped with four ultrasonic humidifiers to improve the humidity control accuracy and the temperature and humidity control range. The constant temperature and humidity air conditioner is also equipped with one rotary dehumidifier and one refrigeration dehumidifier. By combining the rotary dehumidifier and the refrigeration dehumidifier, the temperature and humidity control range is improved.
7. The high-precision constant temperature and humidity test chamber according to claim 3, characterized in that: The machine room (1) is also equipped with a chilled water air conditioning shared unit (17) connected to the fresh air pretreatment unit (4) and the temperature and humidity main treatment system (6). The chilled water air conditioning shared unit (17) is used to provide chilled water for fresh air pretreatment and temperature control of the climate chamber (2). The chilled water air conditioning shared unit (17) includes a condenser, a condenser fan, a water tank, a water pump and a control system. The chilled water air conditioning shared unit (17) is used to generate chilled water. The water pump is used to circulate and transport chilled water. The cooling tower is used to dissipate heat and ensure that the temperature of the chilled water is suitable. The heat exchanger is used to transfer the cooling capacity of the chilled water to the fresh air pretreatment unit (4) and the temperature and humidity main treatment system (6) of the climate chamber (2). The second control system is used to coordinate the operation of the chilled water unit, the water pump, the cooling tower and the heat exchanger to achieve precise control of the chilled water.
8. The high-precision constant temperature and humidity test chamber according to claim 7, characterized in that: The preheating temperature in the fresh air pretreatment unit (4) is controlled by a temperature control formula, which is as follows: Among them, T out For output control signals; K p For proportional gain; K i K is the integral gain; d T is the differential gain; set To set the temperature; T current This is the current temperature.
9. The high-precision constant temperature and humidity test chamber according to claim 8, characterized in that: In the main temperature and humidity processing system (6), humidity is controlled by a humidity control formula to control temperature. The humidity control formula is as follows: Among them, H out For output control signals; K p For proportional gain; K i K is the integral gain; d For differential gain; H set To set the temperature; H current This is the current temperature.
10. The high-precision constant temperature and humidity test chamber according to claim 9, characterized in that: The dehumidification formula used in the dehumidifier of the fresh air pretreatment unit (4) is as follows: ; where m w It is the mass of water vapor; P v It is the partial pressure of water vapor; V is the volume of air; R v It is the gas constant of water vapor; T is the temperature; The heating formula used in the heater of the fresh air pretreatment unit is: Where Q is the heating quantity; m is the air mass; c p ΔT is the specific heat capacity of air; ΔT is the temperature change.