How to calculate the cooling capacity required by the rotary dehumidifier? What are the corresponding standards?

Cooling load design is the main basis for selecting equipment, so it is very important to calculate the building cooling load correctly for the design of the whole system. However, at present, domestic air conditioning design has caused a large number of idle equipment, mainly due to the excessive design cooling load. The calculation method of air conditioning load given in traditional textbooks and design manuals, whether it is the wall load or the door and window load of the envelope, the calculation result is aimed at a specific room, and the equipment capacity of the air conditioning system is based on the cooling load of the whole building. Because the orientation, position, function and internal heat source of each room are different, the maximum cooling load of the building occurs at different times, so the maximum cooling load of each room should be the maximum value of hourly load superposition. According to the survey, some designers in our country simply add up the maximum cooling load of each room when calculating the building cooling load. This wrong calculation method exists in many units. Unfortunately, some HVAC design and calculation software also has such methodological errors, which makes designers not know that they have made mistakes, which is really harmful. Therefore, we must pay enough attention to this to make the determination of design load more reasonable and correct.

The Design Depth Regulation specifies in detail the contents that should be included in the HVAC design calculation. However, quite a few engineering designs have no HVAC design calculation. Although some heating and air conditioning designs have calculation books, their contents are incomplete. Some heating designs only have heat consumption calculation, but there is no hydraulic balance calculation and radiator selection calculation; In some high-rise buildings, the design of central air conditioning and smoke control only has the calculation of summer cooling load, but there is no hydraulic calculation of air conditioning system and water system, no selection calculation of refrigeration and air conditioning equipment, and no calculation of smoke control. Some air conditioning designs, regardless of room size, orientation, level and location (middle or end), use the same index to estimate the cooling load of air conditioning in summer and the heating load of air conditioning in winter, which is not suitable for configuring air conditioning equipment.

The Design Depth Regulation specifies in detail the contents that should be included in the HVAC design calculation. However, in some air conditioning designs, no matter the size, orientation, level and location (middle or end) of the room, it is not appropriate to estimate the cooling load of air conditioning in summer and the heating load of air conditioning in winter according to the same index, and configure air conditioning equipment accordingly. A considerable part of engineering design has no HVAC design calculation. Some air conditioning designs have calculation books, but the contents are incomplete. In some high-rise buildings, the design of central air conditioning and smoke control only has the calculation of summer cooling load, but there is no hydraulic calculation of air conditioning system and water system, no calculation of refrigeration and air conditioning equipment selection, no calculation of smoke control and so on.

According to the actual investigation results of 24 five-star hotels in China, none of them has a cooling load operating rate exceeding 104W/m2 (based on the construction area). For example, the cooling load design value of Guangzhou Garden Hotel is 99W/m2 (according to the construction area). The actual investigation results show that the cooling load design index of half hotels exceeds 104W/m2 (calculated by construction area), and a few hotels have seriously exceeded the standard.

1 The Design Standard for Building Energy Efficiency (GB 50 189-2005), which was implemented in July, 2005, has ten mandatory provisions, among which 5. 1. 1 clearly stipulates that "in the construction drawing design stage, the heating load and hourly cooling load must be calculated one by one." This will play a good role in the correct design and selection of equipment.

However, it should also be noted that the design cooling load includes building cooling load, lighting load, office building personnel load and equipment load, which can be carried out by reliable data and methods. Suitable for many public buildings, such as cultural entertainment, shopping malls, restaurants and other buildings, including hotels. It should be said that it is difficult to define personnel load and equipment load. The lack of sufficient design data in actual design brings uncertainty to designers, which implicitly increases the possibility of equipment selection. It is the building cooling load. In actual engineering design, it is often the architectural specialty that is constantly revised due to the requirements of the owner. When the building is determined, the design time of HVAC personnel is very small. Due to the lack of sufficient design cycle, the phenomenon of setting indicators exists in large numbers. Third, some projects, especially developers and investment projects, are not clear about the internal functions of buildings, and only require designers to give full and adaptive consideration.

Therefore, personally, energy saving is not just a matter for HVAC professionals. The following work needs to be done:

1. The shortest design cycle of air conditioning design is issued by the authoritative department to ensure that HVAC personnel have enough time to do the design well and prevent unreasonable accusations from the leaders and owners of the design institute.

2. Authoritative departments issue reference data of air conditioning design man-days to guide the workload assessment of design institutes. Because the man-day quota issued by the Ministry of Construction in the last century has been dominated by design institutes for decades, the input and output of HVAC professionals have been unreasonable.

3. The authoritative department should organize necessary investigation and measurement (the difference between design and practice and recommended value), and put forward the design data as the basis. You know, the number of public buildings in China is already several billion square meters.

According to the actual investigation results of 24 five-star hotels in China, none of them has a cooling load operating rate exceeding 104W/m2 (based on building area). For example, the cooling load design value of Guangzhou Garden Hotel is 99W/m2 (according to the construction area). The actual investigation results show that the cooling load design index of half hotels exceeds 104W/m2 (calculated by construction area), and a few hotels have seriously exceeded the standard.

Yes, we are working on a project now, and the average load is only 80w/m2.

Good calculation software, correct design parameters and more practical experience are effective ways to solve the load calculation problem. It is better to program the meteorological conditions and calculations in this respect with some time, but the basic data is a problem, which will be very big and waste energy.

Air conditioning design days are not as good as before. Air-conditioning designers are asked which idea is good, but whoever understands the difficulties of air-conditioning designers can only solve other problems such as improving air-conditioning design man-days and saving energy. But the reality is cruel. Air conditioning is an auxiliary type of work in civil engineering. You deserve to increase your workload! ! ! ! !

In the design cooling load and actual engineering design, the architectural specialty is often revised constantly due to the requirements of the owner. When the building is determined, the design time of HVAC personnel is very small. Due to the lack of sufficient design cycle, there are a large number of indicators. Some projects, especially developers' projects and investment projects, are not clear about the internal functions of buildings, and only require designers to give full and adaptive consideration.

Therefore, personally, energy saving is not just a matter for HVAC professionals. The following work needs to be done:

1. The shortest design cycle of air conditioning design is issued by the authoritative department to ensure that HVAC personnel have enough time to do the design well and prevent unreasonable accusations from the leaders and owners of the design institute.

2. Authoritative departments issue reference data of air conditioning design man-days to guide the workload assessment of design institutes. Because the man-day quota promulgated by the Ministry of Construction in the last century has dominated the leadership of design institutes for decades, that is, in 2000, a new design man-day was introduced, the design man-day of architectural scheme was greatly improved, the air-conditioning design man-day was not as good as before, and the input and output of HVAC specialty was unreasonable. Compared with civil engineering, the quota and bonus of HVAC specialty are few and far between, so it is necessary to increase the quota and bonus ratio.

3. The authoritative department shall organize necessary investigation and measurement (differences between design and practice and recommended values), and provide data for the design as the basis. It should be noted that China is vast in territory and abundant in natural resources, with great differences between the north and the south.

Don't just look at the design total load divided by the air conditioning cooling load index of the building area! The total cooling load and partial load of air conditioner are reserved for increasing the building area in the future! If it is really superimposed according to the hourly cooling load of existing rooms, the future building area will increase and the building function will change. How to take countermeasures for air conditioning specialty? Add a small host? Unrealistic! -Let's talk about a more realistic problem: if the design institute doesn't have air conditioning design software, it will only have to do manual work within several design cycles (with all due respect, is this "design cycle" the "design working day" mentioned by the heroes just now? How much energy and time did it take to calculate the air conditioning load? In addition, many energy-saving buildings adopt new envelope structures, and a series of parameters such as delay coefficient cannot be found. How to calculate (accurately calculate) the cooling load of air conditioner? -of course, it is necessary for energy-saving standards. However, things are more complicated and cannot be cut across the board!

Comfort air conditioning has the concept of comfort zone, which is a range. First, a certain range of changes should be allowed. If we study some empirical values carefully, we will find that they are more realistic than detailed calculation. If the indoor design temperature of the office is 26 degrees in summer, people will feel hot after staying for a while, many of which are psychological. If it splits to 22 degrees or even lower. Therefore, I think it is inappropriate to pay attention to the accurate calculation of software. The result of software calculation is only one more calculation basis, and the actual engineering noise calculation is often more important, but it is ignored. Moreover, it is normal for some foreign companies and hotels to request backup, and the actual operating income is far less than the increased project cost. When I graduated, I visited a star-rated hotel in Tianjin. The foreigner asked me to back up a carrier centrifuge. So I think all kinds of software are very helpful to consolidate the understanding of the concept of air conditioning, but the specific projects can only be used as reference, and the design is the result of comprehensive consideration!

I think the software propaganda is a little misleading, which makes most designers or students tend to emphasize the accuracy of software calculation, while ignoring that the most comfortable air conditioners are uncertain solutions in a certain range. Just like an architectural scheme, different angles and ideas will definitely lead to different results. Computing software should not meet the needs of auditing or internal proofreading, but should guide designers to use software as a tool and auxiliary means to comprehensively consider the ideas and methods to solve problems! I think it is reasonable for some electromechanical companies to choose the models of pumps and fans: 1. Mechanical and electrical construction is calculated according to the site. 2. The site conditions shall be submitted to the design institute for review.