Expand and edit the introduction of this paragraph. The fan coil unit is mainly composed of low noise electric machinery , fins and heat exchange coil, etc. The cooling (heating) medium water in the coil is composed of air conditioner Centralized supply in the main engine room. The product standard of fan coil units must be produced in accordance with GB/T 19232-2003 Fan Coil Units. The National Air Conditioning Equipment Quality Supervision and Inspection Center has undertaken many quality supervision and spot checks of national fan coil unit products entrusted by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China. Most of the unqualified items in fan coil unit testing are noise and refrigeration capacity. Horizontal fan coil unit
Edit this section of historical development The historical status and development of China's fan coil units have undergone several different changes. At the initial stage, the understanding of fan coil units remained on the basis of mainly meeting the air volume requirements. It is considered that as long as the air volume is large, it can meet the requirements, and it is a good fan coil. Under the guidance of this concept, the main feature of the fan coil unit produced at that time was that the air volume generally exceeded the standard, which led to high noise and energy consumption of the unit. The unit power cooling capacity of the fan coil unit produced at that time was only about 40W. Because of the loud noise, people had to suffer from annoying noise while enjoying the cold wind brought by air conditioners.
In order to solve the above problems, the country began to revise the product standards of fan coil units. In 2003, the GB/T 19232-2003 Fan Coil Unit issued and implemented strict regulations on the performance of fan coil units. The full performance index detection should include air volume, cooling capacity, heating capacity, water resistance, condensation, and condensate treatment. In view of the quality problems in engineering application, 10.2.2 of the GB 50411-2007 Code for Acceptance of Construction Quality of Building Energy Conservation Engineering issued in 2007 stipulates that "when the fan coil unit and thermal insulation materials enter the site, the following technical performance parameters shall be re inspected, and the re inspection shall be witness sampling for inspection. The cooling capacity, heating capacity, air volume, outlet static pressure, noise and power of the fan coil unit; Random sampling on site for inspection; Check the re inspection report. Inspection quantity: 2% of fan coil units from the same manufacturer shall be reinspected, but not less than 2 ".
In recent years, the manufacturing industry of fan coil units in China has developed rapidly, and the annual output has soared from thousands of units in the early 1980s to millions of units at present. In the mid-1980s, the foreign fan coil unit manufacturing industry, represented by American companies such as Trane, York, Carrier, etc., has completed product upgrading and launched a new generation of products. At that time, the Chinese air conditioning industry was intoxicated with the fact that the domestic fan coil units were close to foreign products in terms of cooling capacity, noise and other isolated parameters, ignoring the real gap in comprehensive performance and use effect, so that this product update failed to cause any response in the Chinese air conditioning industry. However, since 2000, with the implementation of several domestic standards and specifications, domestic air conditioning enterprises have caught up. At present, the performance, variety and domestic products of the new generation of fan coil units are not much different from those of foreign products, and the production bases and research and development centers of foreign enterprises have moved to China one after another.
Because fan coil system has the advantages of easy regulation, easy installation and low cost, its application field is expanding and the product type is also increasing. When the traditional large-scale centralized air conditioning and split household air conditioning can not meet the requirements of modern civilization for the quality of human settlements and residential management, the concept of household midpoint air conditioning came into being, in which fan coil units played an indispensable role. For example, air-cooled cold and hot water unit and fan coil unit combination (such as Trane), air-cooled cold and hot water unit and fan coil unit and floor heating combination (such as Tsinghua Solan), water (ground) source heat pump Unit and fan coil unit combination type, air-cooled water chiller and household boiler and fan coil unit combination type (such as York), etc., household midpoint air conditioning is a new concept that has only appeared in recent years in China, but it has nearly half a century of application experience in the United States. At present, household mid point air conditioners are becoming a condition for Chinese real estate developers to improve the quality of their buildings and their owners to improve their living quality.
Edit the working principle of this section The body of fan coil unit is compact and durable, usually with high-quality plating Zinc plate Casing, condensation surface mounted air duct
The water pan is molded integrally, without welds and welding spots, and the insulation materials conforming to the fire protection specifications are integrally connected to the water pan. Row Water pipe The line is easy to install, and the left and right connecting pipes and return air modes can be changed at any time to match the site conditions. The unit can be installed in any space. Fan coil is usually expanded, which increases the close contact between copper tube and aluminum foil of heat exchanger, and has good heat transfer performance; Reasonable fan and air flow structure design and high-quality sound absorption and thermal insulation materials make the unit noise lower than the national standard 1-3dB (A); Low energy consumption of fan coil unit: the fan and heat exchanger are reasonably matched, and the air volume can be adjusted in three gears to save power for the fan.
The fan coil unit mainly relies on the forced action of the fan to heat the air when it passes through the surface of the heater, thus strengthening the convection heat transfer between the radiator and the air, which can quickly heat the air horizontal concealed fan coil unit in the room
Qi. The fan coil unit is the end device of the air conditioning system. Its working principle is that the air in the room where the unit is located is recycled continuously, so that the air is cooled (heated) after passing through the cold water (hot water) coil unit, so as to keep the room temperature constant. Generally, fresh air is sent into the room after being processed by the fresh air unit to meet the demand of fresh air volume in air-conditioned rooms.
Because this heating method is only based on convection heat transfer, which results in less comfortable indoor, it is only applicable to places where people stay for a short time, such as offices and hotels, hospitals, restaurants, factories, hospitals, exhibition halls, shopping malls, office buildings and other multi room or large space industrial and civil buildings. Due to the increase of fans, the cost and operation cost are increased, and the maintenance and management of equipment are also more complex.
Edit the coil characteristics of this section Vertical fan coil
The structure of fan coil unit is exquisite, compact, durable, beautiful and elegant. The fan coil unit is made of high-quality galvanized sheet casing, and the condensate water pan is formed by molding process in an integrated way. There are no welds, solder joints, and insulation materials that meet the fire protection specifications are connected to the water pan as a whole. The fan coil unit is small in size and light in body design. The drainage pipes and lines are easy to install, and the left and right connecting pipes and return air modes can be changed at any time to match the site conditions. The unit can be installed in any space. The fan coil has high efficiency and advanced tube expansion technology, which ensures the close contact between the copper tube and aluminum foil of the heat exchanger, with good heat transfer performance; The fan coil unit has low noise, reasonable fan and air flow structure design, and high-quality sound absorption and thermal insulation materials, making the unit noise lower than the national standard 1-3dB (A); The fan coil unit has low energy consumption, reasonable matching between the fan and the heat exchanger, and three speed adjustable air volume, so that the power consumption of the fan is lower.
The models and types in this section are edited to meet the design selection in different occasions. The types of fan coil units can be divided into horizontal concealed installation (with air box) fan coil units, horizontal open installation fan coil units and horizontal concealed installation fan coil units [1]
Pipe, vertical concealed fan coil unit, vertical exposed fan coil unit, card type two outlet fan coil unit, card type four outlet fan coil unit, vertical cabinet type fan coil unit air conditioner and wall mounted fan coil unit, etc.
According to the provisions of the national standard Fan Coil Units (GB/T 19232-2003) Part 4 Classification, fan coil units can be classified as follows:
The structural types are horizontal, vertical (including column type and low height type), card type and wall mounted
Separate installation and concealed installation according to installation type
The water inlet direction is divided into left type (facing the unit air outlet, the water supply and return pipes are on the left) and right type (facing the unit air outlet, the water supply and return pipes are on the right).
Edit the control scheme of this section. The fan coil control mostly adopts the local control scheme, which is divided into simple control and temperature control. Simple control: use the three speed switch to manually control the three speed conversion and start stop of the fan. Temperature control: STC series temperature controller automatically controls the opening and closing of STV series electric two-way/three-way valve according to the comparison and calculation between the set temperature and the actual measured temperature; Three speed conversion of fan. Or directly control the three speed conversion and start stop of the fan, so as to achieve the goal of constant temperature by controlling the water flow or air volume of the system.
As the terminal equipment of central air conditioning, the quality of fan coil unit determines the indoor air conditioning effect. The performance mainly includes the guarantee of cooling (heat) supply, air supply volume, noise value ratio, no leakage of condensed water, and the rationality of the design of electrical appliances and sheet metal parts.
Edit the heat exchange performance of this section. When the air volume of fan coil unit is constant and the water supply temperature is constant, the cooling capacity changes with the change of water supply. According to the performance statistics of some fan coil unit products, when the water supply temperature is 7 ℃ and the water supply capacity is reduced to 80%, the cooling capacity is about 92% of the original, indicating that when the water supply capacity changes, the impact on the cooling capacity is relatively slow.
The temperature difference between the supply and return water of the fan coil unit is constant. When the water supply temperature rises, the cooling capacity decreases. According to statistics, when the water supply temperature rises by 1 ℃, the cooling capacity decreases by about 10%. The higher the water supply temperature, the greater the decrease, and the dehumidification capacity decreases.
Under certain water supply conditions, when the air volume of fan coil unit changes, the refrigeration capacity and the enthalpy difference of air treatment change with the change, generally the refrigeration capacity decreases, the enthalpy difference increases, and the power consumption of fan per unit refrigeration capacity changes little.
When the temperature difference between the inlet and outlet of the fan coil increases, the water volume decreases and the heat transfer coefficient of the heat exchange coil decreases. In addition, the temperature difference of heat transfer also changes, so the cooling capacity of fan coil decreases with the increase of the temperature difference of supply and return water. According to statistics, when the water supply temperature is 7 ℃, and the temperature difference of supply and return water increases from 5 ℃ to 7 ℃, the cooling capacity can be reduced by about 17%.
Thermal environment condition refers to the comprehensive effect of physical parameters on human thermal comfort. These physical parameters mainly include air dry bulb temperature, air relative humidity, air flow speed, average radiation temperature, human metabolism and clothing. Among them, air temperature and flow velocity are important parameters to evaluate the thermal comfort conditions provided by fan coil units.
To edit the selection and purchase of fan coil units for maintenance in this section, first provide the supplier with a third-party test report to ensure their product performance, and determine whether they pass the product certification. Product certification is to confirm whether the enterprise's products, processes or services meet the standard requirements and whether it has the ability to continuously and stably produce products that meet the standard requirements by an impartial third-party certification authority through inspection and evaluation of the enterprise's quality management system and sample type test.
Passing product certification is the embodiment of enterprise strength. At present, the unit authorized by the Certification and Accreditation Administration of the People's Republic of China to conduct fan coil unit product certification is China Academy of Building Sciences, which is specifically implemented by the Environmental Measurement and Control Optimization Research Center.
Fan coil units are usually installed directly in air-conditioned rooms, and their service status and quality will affect the indoor noise level and air quality. Therefore, it is necessary to do a good job in the daily maintenance of the main components such as the air filter screen, drip pan, coil unit and fan, so as to ensure that the fan coil unit can function normally without negative impact.
The coil unit is responsible for the important mission of transferring the cold and heat of cold and hot water to the air passing through the fan coil unit. In order to ensure efficient heat transfer, the surface of the coil must be kept as smooth as possible. However, since the fan coil units are generally equipped with coarse efficiency filters with large holes, it is inevitable that dust will pass through the filter and attach to the pipe or fin surface of the coil unit at the beginning of use. If not cleaned in time, the heat exchange capacity between the cold and hot water in the coil and the air flowing out of the coil will be reduced, so that the heat exchange efficiency of the coil can not be fully played. If there is a lot of dust attached, even if some air passages between the fins are blocked, the air supply volume of the fan coil unit will also be reduced, further reducing its air conditioning performance.
The cleaning method can refer to the cleaning method of air filter, but the cleaning cycle can be longer, generally once a year. If the air conditioner is used seasonally, it shall be cleaned once after the air conditioner season ends. As a last resort, it is not necessary to remove the whole part from the installation site for cleaning, so as to reduce the impact of cleaning and dismounting.
Edit the cleaning meaning of this paragraph. After the York fan coil unit has been used for a period of time, there will be dust and bacteria on the fins and impellers. When the dust reaches a certain thickness, the heat dissipation effect of the fins will be affected, which will lead to the room temperature failing to meet the requirements. In addition, the fan coil unit that is not cleaned for a long time will breed a variety of bacteria, which will cause diseases on the human respiratory tract, Therefore, it is recommended that the fan coil should be cleaned regularly.
Cleaning significance:
1. York fan coil unit removes bacteria and dust in the air supply and return system, improving indoor air quality;
2. Reduce the air resistance of the VAV air conditioning unit, improve the heat exchange efficiency, increase the air supply volume, and save energy;
3. Maintain the fan coil system regularly to extend the service life of the unit;
4. Reduce operation cost and improve asset value;
Edit the function of this section (1) The fan coil unit should create an indoor air environment suitable for human comfort. Because the indoor air environment plays a very important role in human comfort, creating the indoor air environment required by human comfort becomes the primary task of air conditioning work. If the indoor air temperature is required to be 24 ° 11Y and the relative humidity is 55% 15%, the air conditioning work should not only maintain a 24 ° temperature base and 55% humidity base, but also ensure that the fan coil unit has a temperature accuracy of 11Y and a humidity accuracy of * 5% (that is, the allowable temperature and humidity fluctuation range), as well as a high freshness and cleanliness. Fan coil [2]
(2) York fan coil unit fan coil unit [3] shall meet the indoor air environment required by process production. Some production processes have high requirements for temperature and humidity environment. Temperature and humidity conditions not only directly affect the normal operation of production processes, but also affect the output and quality of products. Such as textile production, accurate instrument production and drug production process.
(3) Remove harmful indoor gas and heat and moisture emitted in a concentrated way. Carbon dioxide in comfortable air-conditioned rooms and bad smell in toilets, toxic, odorous and other harmful gases produced in the production workshop of process air conditioners, as well as local parts that emit a large amount of heat and moisture, and fan coil units need passage air conditioners and exhaust facilities to eliminate, so as to obtain a good indoor air environment.
Edit the environmental requirements of this paragraph. 1. The temperature of inlet cooling water of fan coil unit [4] should not be lower than 5 ℃, otherwise it may cause unit condensation; The temperature of inlet hot water shall not be higher than 80 ℃ (60 ℃ in common use), otherwise it may cause copper tube corrosion of unit heat exchanger.
2. It is recommended that the operating ambient temperature of fan coil unit is 16~36 ℃ for cooling and 10~30 ℃ for heating; Air relative humidity ≤ 90%.
3. The fan coil unit is only used as a comfort air conditioner and should not be used in special occasions.
4. Do not install fan coil units in areas with corrosive gases.
Sales/installation/maintenance of York fan coil
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