Development and design of dehumidifier scheme

2021-01-05 17:00:25 hongling

Dehumidifiers, also known as dehumidifiers, dryers, and dehumidifiers, can generally be divided into two categories: household dehumidifiers and industrial dehumidifiers. They are a small member of the refrigeration and air-conditioning family. The working principle of the compressor is basically the same as that of an air-conditioning compressor. "The mainstream product of the dehumidifier compressor is the rotary compressor. Compared with the air conditioner, the basic structure and principle are similar. Only the cooling capacity is smaller and the volume is smaller. At the same time, the volume miniaturization is higher.

1. The working principle of the dehumidifier solution

The fan of the dehumidifier draws moist air into the machine and passes through the heat exchanger. At this time, the moisture in the air condenses into droplets and becomes dry air to be discharged out of the machine. This cycle reduces the indoor humidity. After being sucked by a fan, the treated air is first filtered by an air filter, and then cooled and dehumidified on a cooled evaporator, condensing the excess water vapor in the air into water, reducing the air humidity. As the dehumidified condensed water takes away part of the heat and humidity, the temperature of the air is reduced accordingly, making the air temperature and humidity suitable.

The dehumidifier consists of a compressor, a heat exchanger, a fan, a water container, a casing and a controller. Its working principle is: the fan draws moist air into the machine and passes through the heat exchanger. At this time, the moisture in the air condenses It becomes water droplets and becomes dry air to be discharged out of the machine. This circulation reduces indoor humidity. The internal circulation of the dehumidifier: through the operation of the compressor → discharge high-temperature and high-pressure gas through the exhaust port → enter the condenser for cooling → become a low-temperature and high-pressure gas → intercept the flow through the capillary tube → become a low-temperature and low-pressure liquid → evaporate and absorb heat through the evaporator → Back to the compressor, it becomes a low-temperature and low-pressure gas. So it goes back and forth. The external circulation of the dehumidifier: under normal startup → through the operation of the fan → inhalation of moist air from the air inlet → pass through the evaporator → the evaporator absorbs the moisture in the air on the aluminum sheet → becomes dry air → passes through condensation Heat dissipation from the device → blow out from the air outlet.


Second, the classification of dehumidifiers

1. Cooling dehumidifier

As the name suggests, this dehumidifier basically relies on the principle of refrigerant cooling for dehumidification, and is specifically divided into three categories: general dehumidifiers, cooling dehumidifiers, and multifunctional dehumidifiers.

(1) The general dehumidifier means that the air is cooled and dehumidified by the evaporator, heated by the reheater to lower the relative humidity, and the condensation heat of the refrigerant is taken away by the air flowing through the reheater, and the outlet temperature cannot be adjusted. , Dehumidifier used only for heating and dehumidification.

(2) The cooling type dehumidifier refers to the general dehumidifier. Most of the condensation heat of the refrigerant is taken away by the water-cooled or air-cooled condenser, and only a small part of the condensation heat is used to heat the air after the evaporator. The dehumidifier that can be used for cooling and dehumidification means that on the basis of a general dehumidifier, the condensation heat of the refrigerant can be taken away in whole or in part by a water-cooled or air-cooled condenser, and the remaining condensation heat is used for heating through A dehumidifier whose outlet temperature can be adjusted for the air after the evaporator.

(3) Multifunctional dehumidifier refers to a dehumidifier that integrates three functions of heating and dehumidification (general type), cooling and dehumidification, and temperature adjustment and dehumidification. It can still be used when there is no outdoor unit (air cooling) or cooling water (water cooling). A dehumidifier that selects the heating and dehumidification function for dehumidification.

2. Rotary dehumidifier

The main structure of the rotating wheel dehumidifier is a continuously rotating honeycomb drying wheel. The drying wheel is the key component of the dehumidifier to absorb moisture. It is composed of a corrugated medium made of special composite heat-resistant materials. The corrugated medium contains moisture absorbent. This design has a compact structure and can provide a huge surface area for wet air and hygroscopic media to fully contact. Thereby greatly improving the dehumidification efficiency of the dehumidifier

3. Solution dehumidifier

The solution dehumidification air-conditioning system is a new type of air-conditioning product developed based on the active dehumidification air treatment technology that uses a dehumidifying solution as a hygroscopic agent to adjust air humidity and water as a refrigerant to adjust air temperature, which can provide fresh air operating conditions; its core is to use dehumidification The physical properties of the agent, through innovative solution dehumidification and regeneration methods, achieve high-efficiency dehumidification above the dew point temperature. The temperature and humidity adjustment of the system is completely carried out in an open atmosphere at normal pressure, which has the technical characteristics of simple manufacturing, reliable operation, energy saving and high efficiency. This system mainly consists of four basic modules. They are supply air (fresh air and return air) module, humidity control module, temperature control module and solution regenerator module

4. Pipe dehumidifier (absorption)

The pipeline dehumidifier uses an evaporator to cool and dehumidify the air, and recover the condensation heat of the system to make up for the heat lost in the air due to cooling and dehumidification. It is an efficient and energy-saving dehumidification method. It provides a method that can be used in different indoor and outdoor areas. Pipeline temperature and humidity adjustment method and equipment for heating, cooling and dehumidifying indoors under temperature to meet indoor temperature and humidity requirements. Pipeline dehumidification system mainly consists of cooling and dehumidification mode, temperature control and dehumidification mode, heating and dehumidification mode, and heating mode , Automatic defrost composition.


3. Performance comparison of various dehumidifier solutions

1. Cooling and dehumidifier scheme

Advantages of cooling dehumidifier: It has good dehumidification effect, the relative humidity of the room drops quickly, the operating cost is low, no heat source is required, and cooling water is not required. Because of the low energy consumption, simple operation and easy control, it has been widely used in national defense projects. , Civil air defense engineering, various warehouses, libraries, archives, underground engineering, electronics industry, precision machinery processing, medicine, food, agricultural seed storage and workshops of various industrial and mining enterprises.

Disadvantages of cooling dehumidifiers: In places with high humidity requirements, it is obviously uneconomical to use frozen dehumidification, and the noise is relatively large.

2. Runner dehumidifier scheme

Advantages: The rotary dehumidifier does not require cold coal, so there is no compressor, which is about half the weight of a traditional dehumidifier. Because there is no compressor, it is quieter in operation, but compared with the current refrigeration dehumidifier, it is not necessarily quieter in the normal mode. On the contrary, the silent mode is really very quiet, so quiet that it is almost imperceptible.

Disadvantages: Renewable energy consumption is large and expensive.

3. Solution dehumidifier solution

Advantages of the solution dehumidifier: When introducing fresh air, the small multifunctional solution dehumidifier exchanges heat with the indoor return air before the fresh air enters the cooling and dehumidifying core, which can recover most of the indoor energy and reduce the entry of the cooling and dehumidifying core. The enthalpy value of the fresh air, thereby reducing the thermal load of the compressor, greatly improving the efficiency of the compressor, and high efficiency and energy saving. It organically combines innovative liquid dehumidification technology with mature heat pump technology, miniaturizes the unit, and creates a brand-new high-efficiency air-conditioning dehumidification system that can be used universally. It not only has the air conditioning quality of a central air-conditioning system, but also has a small decentralized air-conditioning system. The machine is convenient and efficient.

Disadvantages: low dehumidification and moisture permeability of the solution, poor strength, high cost, in addition to the need for additional cold and heat sources, the structure is relatively complex

4. Pipeline dehumidifier scheme

Advantages of pipeline dehumidifier: The compressor adopts a fully enclosed flexible scroll type; through the scientific and reasonable optimization design of the refrigeration system, the heat exchanger has compact structure, good pressure resistance, high heat exchange efficiency, low noise, reliable operation, and high energy efficiency ratio. .

The disadvantage is that the maintenance cost is high, and it is more suitable for use in large areas.


Fourth, the defrosting principle of the dehumidifier

When the compressor dehumidifier is used in a relatively low temperature environment (usually below 10 degrees Celsius), it will cause the dehumidifier heat exchange system to frost, and this process is unavoidable, so the compressor dehumidifier is at ambient temperature In the lower case, it will enter the defrosting state regularly. At this time, the dehumidifier will first stop the compressor, and use the evaporator heating wire (part of the heat exchange system) to heat the temperature of the heat exchange plate, and then output through the fan to produce a defrosting effect.

This time-consuming needs to be determined by the ambient temperature. The lower the ambient temperature, the longer the time-consuming. During the defrosting process, the compressor-type dehumidifier cannot perform dehumidification work, so for a lower temperature environment, the compressor-type dehumidifier dehumidifies The effect is not ideal. If it is a dehumidification environment with low ambient temperature, you can choose a new type of rotary dehumidifier.

Five, the application advantages of the dehumidifier solution

The dehumidifier can remove the damp moisture through operation, making the air dry. Widely used in computer rooms (medicine, electricity, telecommunications), workshops and warehouses (electronics, footwear, clothing, tobacco, food, leather, glass, paper), file management (banks, public security, museums, archives, government agencies), etc. The environment, family, etc. where the above space area is small. The following are the application advantages of the two types of dehumidifiers.

1. Scheme of household dehumidifier

The household dehumidifier is developed for the harsh and humid environment. It can not only effectively improve the humid living and production environment, and make it reach the ideal state, but also can remove the mold brought by the humid environment. The dehumidifier can remove damp moisture and suspended particles through operation, and make the air dry. It is also an air purifier. The household dehumidifier is used in all aspects of production and life to create a comfortable, dry and quiet modern life for users space.

The research report of household dehumidifiers pointed out that the human body has high requirements for the humidity of the living environment. The relative humidity is preferably 55-65%, preferably not less than 50% in winter and not more than 80% in summer. If the humidity is too high, it is easy to cause: clothing, leather, damp and mold; food, medicine, tobacco, deterioration; electrical appliances and precision instruments, damp and damage; water stains on walls and floors, causing documents, decorations and collections to be damp and moldy; spring bacteria breed, easy to induce respiratory tract Diseases and rheumatism; the human body is difficult to dissipate heat in summer, which increases the chance of heatstroke; in winter, heat conduction is accelerated, making people feel cold. It can be seen that reducing the humidity is not only a concern for the storage department, but also for the people who live at home. At present, the main production areas of global household dehumidifiers are concentrated in Australia, Italy, Japan and Taiwan, China.

2. Industrial dehumidifier solution

Industrial dehumidifiers are very professional electromechanical equipment, and people do not know enough about them. When selecting dehumidifiers, they often make simple selection based on the area of the dehumidified area. Industrial workshops, warehouses and other air purification equipment that belong to process requirements have strict requirements for target humidity.

Therefore, industrial dehumidifiers and other dehumidification equipment cannot be selected based solely on the area of use. Professional industrial dehumidifier suppliers select models based on the overall wet load of the use site. Specifically, the dehumidifier is used to calculate key parameters such as total refrigeration capacity and dehumidification capacity per unit time based on comprehensive factors such as its area, floor height, initial humidity value, target humidity value, indoor airtightness, moisture source, fresh air supply, etc. Selection.


6. Use and maintenance of dehumidifier

The installation is complete and you can start using it. Before the dehumidifier is operated, the doors and windows should be closed first to prevent humid air from entering the room, which will affect the dehumidification effect. If there is no special need, try to reduce the number of opening and closing of doors and windows as much as possible. It is the same as reducing the number of times of opening and closing the door of the refrigerator. After a period of use, the air inlet filter of a household dehumidifier will accumulate dust. The dust accumulation will be too dense and thick, which will affect the dehumidification effect, and the humidity sensor of the machine is generally placed On the ventilated surface, if the environment is not good and the humidity sensor is blocked by dust, the sensor cannot display and control the humidity. A soft brush can be used to remove the dust on the sensor and keep the sensor fresh. After using for a period of time, the user should stop the machine at least once a week to do some general maintenance, such as whether the machine filter needs to be cleaned, whether the machine has abnormal noise, etc., it is best to do a regular inspection every six months to a year to ventilate the front and back. Smooth, pour out the water in the water tank in time to avoid the breeding of bacteria.

When not in use for a long time, the power plug should be unplugged and the whole machine should be cleaned. Volatile oil, thinner, and detergent may cause damage to the machine, please do not use it; pour out all the water in the collecting tank, remove the dust on the filter, and put it in Places not exposed to sunlight and well ventilated. In addition, the dehumidifier must not be placed on its side or upside down during storage to avoid damage to the compressor. Most dehumidifiers are controlled by digital microcomputers. Due to the precise control of the original components, non-professionals should not disassemble it at will or change the function frequently. Reduce its service life.