How to design the HVAC ventilation system for tall buildings ?Buildings with a space height greater than 5 meters and a volume greater than 10,000 square meters are called tall space buildings. For example, large buildings, shopping malls, theaters, concert halls, conference halls, stadiums, exhibition halls and other buildings are all tall space buildings. So how to design the HVAC ventilation system of such buildings? Let's learn together
1. Overview of HVAC ventilation system in tall spaces:
1) Tall and large space buildings have the characteristics of high height and large volume, which will form a temperature gradient at the spatial level, and the indoor airflow is susceptible to external influences. More considerations need to be taken in the design of their HVAC ventilation system to avoid influence The application effect of tall space buildings.
2) In the process of designing and utilizing the HVAC ventilation system in large spaces, it is necessary to implement load requirements for the operation of the air conditioning system in different functional areas, and implement practical and effective design work to ensure that the HVAC ventilation system is used in this aspect of construction The health of the operation.
2. Design points of HVAC ventilation system in tall spaces:
In practice, when carrying out the design of HVAC ventilation system in tall spaces, in order to make the design scheme have good applicability, it is necessary to understand the design points of this type of system. Specifically include the following:
1) The main points of the design of the all-air air conditioning system
Designers should clarify these design points when designing the top-to-bottom-back full-air conditioning system based on the actual situation of tall buildings and the functional characteristics of the HVAC ventilation system:
①Set a return air vent next to the side wall or the seat below, which can convey the airflow to the personnel area from top to bottom, and discharge it by the return air system, and place the mechanically concentrated exhaust system on the top of the tall space. Give full play to its application advantages in practice.
②Control the distance between the cold and heat sources of the air-conditioning system and the ground, and it is necessary to think about whether the wind speed of the air outlet is effective, and through the cyclone air outlet with the characteristics of large air volume, low noise, controllable wind speed, and stable resistance. Use, optimize the use function of the air supply system in the tall space, and give the necessary support for the scientific design of the air conditioning system.
③In practice, it is also necessary for designers to carry out the design work of the all-air air conditioning system for the upper and lower returns through comprehensive consideration of environmental protection requirements, cost-economic requirements, etc., to promote its role in the application of tall space buildings The effect is more significant.
2) Design points of the system in the auxiliary room
In the process of completing the design of the HVAC ventilation system in the tall space, in order to ensure its good application in the auxiliary room, it is necessary to clarify the design points of these aspects:
①The design of the HVAC ventilation system in the auxiliary room of the tall space needs to pay attention to the efficient use of energy, pay attention to the reasonable selection and use of the fresh air system, the constant temperature and humidity system, and the multi-line system, and control the corresponding design work process , Efficiently complete the design of the auxiliary room air-conditioning system.
②By considering the energy-saving design of the air-conditioning system in the auxiliary room, it is helpful to reduce the design cost of the HVAC ventilation system in the tall space, and can broaden its design work ideas, and maintain the good application status of such systems
3) Design points of heating system
In combination with the structural characteristics and structural conditions of tall and large space buildings, in the process of improving its service functions, it is also necessary to consider the relevant heating system design points, including:
①Designers should pay attention to the use of auxiliary heating methods such as air-conditioning heating, floor heating or radiators according to the climatic conditions of the area where the tall space building is located, the application value of the heating system, etc., and control the temperature of the auxiliary heating when necessary. The main system can be shut down, so as to achieve the purpose of energy saving and consumption reduction in the operation of the heating system of tall buildings, and avoid affecting the application effect of its design scheme.
②Improve the utilization efficiency of the floor heating system in high-temperature places in high and large spaces, and use the method of gradually increasing the distance of the pipeline from the middle to the periphery in the construction of this type of system, so as to achieve the purpose of enhancing the operating effect of the floor heating system in the practice of tall space buildings. Complete the corresponding design work.
4) Design essentials of the lower air supply air conditioning system
In the halls of large buildings with large spaces, because of the low frequency of use, the large space and the large number of people, and the strict requirements for noise, this type of hall generally needs to use the down-air air conditioning system. The key points of its design include:
①Set up the air supply vent under the seat, and set the return air vent on the ceiling. It is necessary to fully consider the effective control of the temperature difference of the air supply vent according to the user's comfort requirements, so as to provide for the development of the design work of the air conditioning system in the tall space. Reference information to reduce the incidence of design problems.
②Based on the design of air supply and air conditioning system in large spaces, designers need to pay attention to the effective control of temperature and air flow rate in the personnel activity area, give them a good experience, and gradually improve the design quality of building air supply and air conditioning systems in this respect.
5) Design points in other aspects
① Design points of stratified air conditioning system. When designing the hierarchical air-conditioning system for tall spaces, these design points should be clarified: designers should set high-speed nozzles in the middle of the tall spaces as the dividing line between the working area and the non-working area, and provide the working area of the building in this respect. More suitable airflow, and the return air outlet of the air-conditioning system is arranged at a lower position on one side of the air supply outlet to realize energy-saving design in this respect. In the process of determining the airflow organization of the stratified air conditioning system in a tall space, the side delivery and bottom return method should be considered, and the air supply port needs to be set on the building wall, and the effective control of its wind speed and temperature difference should be considered to improve the operating efficiency of the stratified air conditioning system. At the same time, it enriches the design content of HVAC ventilation system in tall spaces.
②The design points of the fresh air heat recovery system. In the development of this type of system design work for tall space buildings, these points need to be considered: set up air conditioning units and exhaust fans, and use the first air heat exchanger in conjunction with the indoor exhaust system to complete the heat exchange in the application of tall space buildings. Processing work to realize the efficient use of the fresh air heat recovery system to ensure its good operating effect and reliability of design quality.
3. Relevant measures to improve the design level of HVAC ventilation systems in tall spaces
In order to continuously improve the design level of the HVAC ventilation system in tall spaces in long-term practice, it is necessary to consider the scientific use of these measures:
① Actively carry out professional training activities, implement a good reward and punishment mechanism, and comprehensively improve the overall quality of designers, so as to enhance the professionalism in the design of HVAC ventilation systems in tall spaces and lay the foundation for the improvement of its design level.
②Strengthen the use of information technology, provide effective technical support for the development of HVAC ventilation system design in tall spaces, realize the integrated utilization of rich information resources, and improve the level of informationization in the formation of design plans in this regard.
③Control the design process of the HVAC ventilation system in tall and large spaces, deal with the details of it, and give more support to the improvement of its design level.
In summary, through the clarification of these design points and the coordinated use of measures, it is helpful to improve the design efficiency and quality of HVAC ventilation systems in tall spaces, and promote such systems to play their due role in practical applications. Therefore, in the future, in the process of improving the application level of HVAC ventilation systems in tall spaces and optimizing their use functions, we should pay attention to the effective design of such systems, and implement targeted design work in place to promote the final design plan. Reasonable and scientific. On this basis, the scientific design of HVAC ventilation systems in tall spaces can be realized, and the practical experience in the design can be enriched.