Large-air-volume replacement type fresh air system based on total heat recovery of air source heat pump

Abstract

The invention discloses a large-air-volume replacement type fresh air system based on total heat recovery of an air source heat pump. The large-air-volume replacement type fresh air system comprises afresh air purifying and heating unit, an exhaust heat recovery unit and a liquid working medium circulating system. After outdoor fresh air (fresh air) is purified by a coarse filtering layer, a pretreatment filtering layer, a gas purifying layer and a pm 2.5 filtering layer, the fresh air is heated to be close to the room temperature through heat energy recycled from exhausted air by the air source heat pump and then enters a room. According to the technology, the purified and heated fresh air replaces indoor air in a forced ventilation mode, and the requirements for fresh air volume and airquality specified by national standards can be fully met. Meanwhile, related standards of noise, energy conservation and the like are met. Lost heat energy can be recovered from the exhausted air bythe air source heat pump and less electric energy is consumed, so that the air inlet and outlet quantity balance is realized, the heat balance is also realized, and the indoor temperature is maintained.

Description

technical field [0001] The invention relates to a large air volume displacement fresh air system based on the total heat recovery of an air source heat pump, which is especially suitable for ventilation in densely populated places such as school classrooms. Background technique [0002] Indoor air quality is affected by various pollutants released by building materials, decoration, furniture, objects, kitchens, toilets, and human bodies, and it will cause serious pollution if outdoor fresh air (fresh air) is not introduced. Since indoor pollution is the superposition of indoor and outdoor pollutants, indoor pollution is more serious than outdoor. The more people in the room, the more oxygen will be consumed, and the more CO2, stench and other gases will be produced. Oxygen deficiency and air pollution will seriously affect work, study and health. The monitoring results show that indoor air pollution has become very prominent. The concentration of CO2, a pollution indicator ...

AI Technical Summary

Problems solved by technology

Adolescents are the future of the country. They are in an important stage of learning and growing physically. Students spend a long time in the classroom and are the key group of cross-infection. The country has clearly stipulated various indicators of the fresh air standard early on. There is no major breakthrough, and all standard indicators cannot meet the requirements, so it has not been popularized

During the severe smog in 2015, the local education department, under the appeal of parents, demonstrated the installation of fresh air systems in some schools, and finally suspended them because they could not meet the standards and other technical problems. The main problems were serious shortage of fresh air volume, substandard air quality, and noise In addition to exceeding the standard, there are also problems such as low heat recovery and no temperature compensation

[0008] 3. Seriously insufficient fresh air volume

According to the standard, the fresh air volume of primary school classrooms is 855m per hour 3 , middle school is 950m 3 , but the air volume of the existing fresh air system is mostly only 300m 3 Left and right, there is a big difference, which is also the main reason for the substandard indoor air quality

The existing fresh air system is because each classroom is a small and complete independent system. If a large air volume fan is used, the noise will increase due to high wind pressure, and the volume of related equipment such as heat exchangers, filtration and purification will increase. If multiple sets are used Low-noise fresh air system means limited classroom space

[0009] 4. Indoor air quality is not up to standard

The above situations will affect the replacement efficiency of the fresh air system to varying degrees, requiring a larger fresh air volume to meet the standard

[0010] 5. Excessive noise

Exhaust heat recovery in existing fresh air systems mostly adopts heat exchangers, and the heat transfer efficiency detected under certain conditions is relatively high, but due to the limited space in the fresh air fan, the actual heat transfer efficiency will not exceed 50%.

In terms of heat recovery, due to the lack of exhaust air caused by cross air leakage, the heat recovery is small, and due to the low replacement efficiency, the air volume must be increased, resulting in increased heat loss

To sum up, the heat recovery efficiency of the existing fresh air system cannot represent the amount of heat recovery, and the actual recovered and functioning heat is much less than 50%

[0012] 7. Most of the existing classroom fresh air systems do not have temperature compensation

According to the small air volume of the existing fresh air system, the temperature drop of 1°C to 2°C in winter will not have a great impact on the room temperature. If the standard air volume is increased by 2 times or even greater, the indoor temperature will be significantly reduced, and heat must be provided for temperature compensation. , thus increasing equipment, increasing volume, increasing cost and energy consumption

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