Calculation Model of Ventilation Times of Ventilation System in Production Workshop?

Ventilation Rate Calculation Model of Ventilation System in Production Workshop

in the process of chemical production, the ventilation system of the production workshop is an important facility to protect the health of workers, improve production efficiency and prevent the spread of pollutants. As the core parameter of the design and operation of the ventilation system, the ventilation rate directly affects the performance and effect of the ventilation system. This paper will analyze in detail the "calculation model of the ventilation rate of the ventilation system in the production workshop" and discuss its significance and calculation method in practical application.

Definition and significance of 1. ventilation times

the number of air changes refers to the number of times the air in the entire production workshop is completely replaced per unit time. Specifically, the number of air changes is an important indicator to measure the efficiency of the ventilation system, and its calculation formula is:

[N = \frac{Q}{V}]

among them:

• (N) indicates the number of air changes (times/h);
• (Q) indicates the fresh air volume or total air volume of the ventilation system (m³/h);
• (V) represents the volume of the production workshop (m³).

The number of air changes directly affects the air quality, pollutant concentration and temperature and humidity control in the workshop. In chemical production, the type and nature of pollutants determine the number of air changes required. Reasonable ventilation times can effectively reduce the concentration of harmful gases, protect the health of workers, and also reduce energy consumption and improve production efficiency.

The basic principle of the calculation model of 2. ventilation rate.

The model for calculating the number of air changes is based on the following assumptions:

1. uniform mixing assumption: Assuming that the air distribution in the workshop is uniform, the number of air changes can represent the average air change efficiency of the entire workshop.
2. steady-state condition assumption: It is believed that the emission of pollutants and the operation of the ventilation system are in a stable state, that is, the concentration of pollutants no longer changes with time.

In the actual calculation, the calculation of the number of air changes needs to be combined with the specific conditions of the workshop, such as the emission of pollutants, the volume of the workshop, the design parameters of the ventilation system, etc. The following are the general steps of the air change calculation model:

1. determination of pollutant emissions: According to the characteristics of the chemical process, calculate the total emissions of various pollutants in the workshop (expressed by volume flow).

2. Determine the target pollutant concentration: Determine the maximum allowable concentration of target pollutants in the workshop according to national or industrial environmental protection standards.

3. Calculate the number of air changes: Based on the pollutant emissions and target concentrations, calculate the required number of air changes. The formula is as follows:

   [N = \frac{Q{\text{emit}}}{C{\text{target}} \cdot V}]

   among them:

• (Q_{\text{emit}} ) represents the emission of pollutants (m³/h);
• (C_{\text{target}} ) indicates the target pollutant concentration (mg/m³);
• (V) represents the volume of the workshop (m³).

3. the main factors affecting the number of air changes

1. types and nature of pollutants: Different pollutants have different toxicity, odor and physical and chemical properties, so the number of air changes required is also different. For example, a highly toxic gas may require a higher number of air changes.

2. Volume and structure of workshop: The volume of the workshop directly affects the calculation of the number of air changes. Larger workshops usually require higher air changes to achieve the same purification effect.

3. Type and performance of ventilation system: The design type of the ventilation system (such as natural ventilation, mechanical ventilation) and the performance of the fan (such as air volume, wind pressure) will also affect the calculation and realization of the number of air changes.

4. Change of working condition: Changes in the production process, the operating status of the equipment, and the activities of the staff in the workshop will affect the demand for ventilation times.

Practical application of the model for calculating the number of 4. ventilation

in practical application, the air change rate calculation model needs to be adjusted and optimized in combination with the specific production conditions and the design parameters of the ventilation system. Here are some common practical application considerations:

1. testing and verification: After designing and installing the ventilation system, it is necessary to verify the calculation results of the number of air changes through actual tests. For example, by measuring the air flow and pollutant concentration in the workshop, the actual air exchange efficiency of the ventilation system is evaluated.

2. Dynamic adjustment: According to the actual situation in the production process, the ventilation rate is dynamically adjusted. For example, when pollutant emissions increase, the number of air changes should be appropriately increased to maintain the air quality in the workshop.

3. Economic considerations: The calculation of the number of air changes should not only meet the process requirements, but also consider energy consumption and operating costs. Excessively high air exchange rate may lead to increased energy consumption, while excessively low air exchange rate may not achieve the purification effect.

5. summary and prospect

the air change rate calculation model is an important tool for the design and optimization of ventilation system in chemical production workshop. Through the comprehensive analysis of pollutant emissions, workshop volume, target concentration and other factors, the scientific calculation and reasonable design of the number of air changes can be realized, so as to ensure the air quality and production safety in the workshop.

With the improvement of environmental protection requirements and the progress of production technology, the calculation model of ventilation times also needs to be continuously optimized and improved. Future research directions can include the following:

1. development of more accurate pollutant dispersion models;
2. consider the effect of airflow organization in the workshop on air exchange efficiency;
3. the adaptive regulation of ventilation rate by intelligent ventilation system was studied.

Through continuous research and practice, the air change rate calculation model will be more suitable for the actual needs of chemical production, and provide strong support for the optimal design and efficient operation of the ventilation system.