shaohai - Industrial purification heat recovery

The utilization of air-to-air heat exchangers in ventilation and energy-saving engineering

The core function of an air-to-air heat exchanger is to transfer the residual heat carried in the exhaust air (indoor exhaust air) to the fresh air (outdoor intake air) through heat exchange, without directly mixing the two airflows. The entire process is based on the principles of heat conduction and energy conservation, as follows:

Exhaust waste heat capture:
The air expelled indoors (exhaust) usually contains a high amount of heat (warm air in winter and cold air in summer), which would otherwise dissipate directly to the outside.
The exhaust air flows through one side of the heat exchanger, transferring heat to the heat conducting material of the heat exchanger.
Heat transfer:
Air to air heat exchangers are usually composed of metal plates, tube bundles, or heat pipes, which have good thermal conductivity.
Fresh air (air introduced from outside) flows through the other side of the heat exchanger, indirectly contacting the heat on the exhaust side, and absorbing heat through the wall of the heat exchanger.
In winter, fresh air is preheated; In summer, the fresh air is pre cooled (if the exhaust air is air conditioning cold air).
Energy recovery and conservation:
By preheating or pre cooling fresh air, the energy consumption of subsequent heating or cooling equipment is reduced. For example, in winter, the outdoor temperature may be 0 ° C, with an exhaust temperature of 20 ° C. After passing through a heat exchanger, the fresh air temperature may rise to 15 ° C. This way, the heating system only needs to heat the fresh air from 15 ° C to the target temperature, rather than starting from 0 ° C.
Airflow isolation:
Exhaust and fresh air flow through different channels in the heat exchanger to avoid cross contamination and ensure indoor air quality.
technological process
Exhaust collection: indoor exhaust gas is guided to the air-to-air heat exchanger through a ventilation system (such as an exhaust fan).
Fresh air introduction: Outdoor fresh air enters the other side of the heat exchanger through the fresh air duct.
Heat exchange: Inside the heat exchanger, exhaust and fresh air exchange heat in isolated channels.
Fresh air treatment: Preheated (or pre cooled) fresh air enters the air conditioning system or is directly sent into the room, and the temperature or humidity is further adjusted as needed.
Exhaust emission: After completing heat exchange, the exhaust temperature decreases and is finally discharged outdoors.
Types of air-to-air heat exchangers
Plate heat exchanger: composed of multiple layers of thin plates, with exhaust and fresh air flowing in opposite or intersecting directions in adjacent channels, resulting in high efficiency.
Wheel heat exchanger: using rotating heat wheels to absorb exhaust heat and transfer it to fresh air, suitable for high air volume systems.
Heat pipe heat exchanger: It utilizes the evaporation and condensation of the working fluid inside the heat pipe to transfer heat, and is suitable for scenarios with large temperature differences.
Vorteil
Energy saving: Recovering 70% -90% of exhaust waste heat, significantly reducing heating or cooling energy consumption.
Environmental Protection: Reduce energy consumption and lower carbon emissions.
Enhance comfort: Avoid direct introduction of cold or hot fresh air and improve indoor environment.

Mine exhaust heat extraction box with built-in air-to-air heat exchanger

The built-in air-to-air heat exchanger in the mine exhaust heat extraction box is a device specifically designed to recover waste heat from mine exhaust air. Mine exhaust refers to the low-temperature, high humidity waste gas discharged from a mine, which usually contains a certain amount of heat but is traditionally discharged directly without being utilized. This device uses a built-in air-to-air heat exchanger (i.e. air-to-air heat exchanger) to transfer heat from the exhaust air to another stream of cold air, thereby achieving the goal of waste heat recovery.

Arbeitsprinzip
Lack of air input: The mine's lack of air is introduced into the heat extraction box through the ventilation system. The temperature of the exhaust air is generally around 20 ℃ (the specific temperature varies depending on the depth of the mine and the environment), and the humidity is relatively high.
Function of Air to Air Heat Exchanger: The built-in air to air heat exchanger usually adopts a plate or tube structure, and the exhaust air and cold air exchange heat through a partition type in the heat exchanger. The heat from the lack of wind is transferred to the cold air, while the two airflows do not mix directly.
Heat output: After being heated by heat exchange, the cold air can be used for anti freezing of mine air inlet, heating of mining area buildings, or domestic hot water, while the exhaust air is discharged at a lower temperature after releasing heat.
Characteristics and advantages
Efficient and energy-saving: Air to air heat exchangers do not require additional working fluids and directly utilize the heat transfer from air to air. They have a simple structure and low operating costs.
Environmental friendliness: By recycling exhaust heat and reducing energy waste, it meets the requirements of green and low-carbon development.
Strong adaptability: The equipment can be customized and designed according to the flow rate and temperature of the mine exhaust, suitable for mines of different scales.
Easy maintenance: Compared to heat pipe or heat pump systems, air-to-air heat exchangers have a relatively simple structure and require less maintenance.
Anwendungsszenarien
Anti freezing at the wellhead: Use the recovered heat to heat the mine air intake and avoid freezing in winter.
Building heating: providing heating for office buildings, dormitories, etc. in the mining area.
Hot water supply: Combined with the subsequent system, provide a heat source for domestic hot water in the mining area.
precautions
Moisture treatment: Due to the high humidity of the exhaust air, the heat exchanger may face the problem of condensation water accumulation, and a drainage system or anti-corrosion materials need to be designed.
Heat transfer efficiency: The efficiency of an air-to-air heat exchanger is limited by the specific heat capacity and temperature difference of the air, and the recovered heat may not be as high as that of a heat pump system, but its advantage lies in its simple structure.

Rotary heat exchanger manufacturers

There are several well-known rotary heat exchanger manufacturers that provide high-efficiency solutions for HVAC, industrial, and energy recovery applications. Below are some leading companies:

1. Global Rotary Heat Exchanger Manufacturers

✅ Heatex (Sweden) – Specializes in air-to-air rotary and plate heat exchangers for HVAC and industrial applications.
✅ Klingenburg GmbH (Germany) – Offers rotary heat exchangers with advanced coatings for high humidity and corrosive environments.
✅ Seibu Giken (Japan) – Known for its desiccant rotors and energy recovery wheels, ideal for pharmaceutical and cleanroom applications.
✅ FläktGroup (Germany) – Supplies energy-efficient rotary heat exchangers for large commercial and industrial buildings.
✅ REC Air Handling (Netherlands) – Provides customizable rotary heat exchangers for HVAC and industrial heat recovery.

2. China-Based Rotary Heat Exchanger Manufacturers

✅ Hoval – Specializes in plate and rotary heat exchangers for HVAC and industrial processes.
✅ Holtop – Manufactures energy recovery ventilation (ERV) systems with rotary heat exchangers.
✅ Zibo Qiyu – Offers aluminum-based rotary heat exchangers for air handling systems.
✅ Shanghai Shenglin – Produces rotary wheels for air-to-air heat recovery applications.

3. Key Features to Consider

✔ Material – Aluminum, coated surfaces (for corrosion resistance), or desiccant-coated wheels (for humidity control).
✔ Efficiency – High heat recovery efficiency (up to 85%) for energy savings.
✔ Application – Industrial HVAC, cleanrooms, pharmaceutical, or general ventilation.
✔ Customization – Size, coatings, and integration with existing systems.

Kiln waste heat recovery and reuse system - gas stainless steel cross flow heat exchanger scheme

The kiln waste heat recovery and reuse system aims to fully utilize the high-temperature heat in the kiln exhaust gas, and achieve a win-win situation of energy conservation and environmental protection through gas stainless steel cross flow heat exchangers. The core of this solution lies in the use of a stainless steel cross flow heat exchanger, which efficiently exchanges heat between high-temperature exhaust gas and cold air, generating hot air that can be reused.

Working principle: The exhaust gas and cold air flow in a cross flow manner inside the heat exchanger and transfer heat through the stainless steel plate wall. After releasing heat from exhaust gas, it is discharged. Cold air absorbs the heat and heats up into hot air, which is suitable for scenarios such as assisting combustion, preheating materials, or heating.

Advantages:

Efficient heat transfer: The cross flow design ensures a heat transfer efficiency of 60% -80%.
Strong durability: Stainless steel material is resistant to high temperatures and corrosion, and can adapt to complex exhaust environments.
Flexible application: Hot air can be directly fed back to the kiln or used for other processes, with significant energy savings.
System process: Kiln exhaust gas → Pre treatment (such as dust removal) → Stainless steel heat exchanger → Hot air output → Secondary utilization.

This solution is simple and reliable, with a short investment return cycle, making it an ideal choice for kiln waste heat recovery, helping enterprises reduce energy consumption and improve efficiency.

ZiBo QiYu manufacturer

ZIBO QIYU AIR CONDITION ENERGY RECOVERY EQUIPMENT CO., LTD. We have kinds of air to air heat exchangers, such as AHU, HRV, heat tube heat exchangers, rotary heat exchangers, steam heating coil, surface air cooler.

All these products can be customized, you just need to tell me your requirements, and we have professional model selection software, we can help you choose the most suitable model.

If you're interested in our products, you can look through our website to get further information.

Website:https://www.huanrexi.com

Application of Air-to-Air Heat Recovery Exchanger in Livestock Ventilation

The Air-to-Air Heat Recovery Exchanger plays a vital role in the livestock ventilation industry by enhancing energy efficiency and maintaining optimal indoor conditions. Designed to recover waste heat from exhaust air, this exchanger transfers thermal energy from the warm, stale air expelled from livestock facilities to the incoming fresh, cooler air without mixing the two streams. In poultry houses, pig barns, and other breeding environments, where consistent temperature control and air quality are critical, it reduces heating costs in winter by pre-warming fresh air and mitigates heat stress in summer through effective thermal regulation. Typically constructed with corrosion-resistant materials like aluminum or stainless steel, it withstands the humid and ammonia-rich conditions common in livestock settings. By integrating into ventilation systems, the exchanger not only lowers energy consumption but also supports sustainable farming practices, ensuring animal welfare and operational efficiency. Its application is particularly valuable in large-scale breeding operations aiming to balance cost-effectiveness with environmental responsibility.

Plate heat recovery exchanger made in china

Heat exchangers are mainly made of materials such as aluminum foil, stainless steel foil, or polymers. When there is a temperature difference between the airflow isolated by aluminum foil and flowing in opposite directions, heat transfer occurs, achieving energy recovery. By using an air to air heat exchanger, the heat in the exhaust can be utilized to preheat the fresh air, thereby achieving the goal of energy conservation. The heat exchanger adopts a unique point surface combination sealed process, which has a long service life, high temperature conductivity, no permeation, and no secondary pollution caused by the permeation of exhaust gas.

Application of Cross Flow Heat Exchanger in Indirect Evaporative Cooling System of Data Center

The application of cross flow heat exchangers in Indirect Evaporative Cooling (IDEC) systems in data centers is mainly reflected in efficient heat exchange, reducing energy consumption, and improving data center cooling efficiency. Here are its key roles and advantages:

Basic working principle
Cross flow heat exchanger is a type of heat exchange device whose structure allows two streams of air to cross each other while maintaining physical isolation. In indirect evaporative cooling systems in data centers, it is typically used for heat exchange between cooling air and outdoor ambient air without direct mixing.
The workflow is as follows:
The primary air (data center return air) exchanges heat with the secondary air (external ambient air) through one side of the heat exchanger.
The secondary air evaporates and cools in the humidification section, reducing its own temperature, and then absorbs heat in the heat exchanger to cool the primary air.
After the primary air is cooled down, it is sent back to the data center to cool down the IT equipment.
The secondary air is ultimately discharged outdoors without entering the interior of the data center, thus avoiding the risk of pollution.
Advantages in Data Centers
(1) Efficient and energy-saving, reducing cooling demand
Reduce cooling load: By using cross flow heat exchangers, data centers can utilize external air cooling instead of relying on traditional mechanical refrigeration (such as compressors).
Improve PUE (Power Usage Effectiveness): Reduce the operating time of mechanical cooling equipment, lower energy consumption, and make PUE values closer to the ideal state (below 1.2).
(2) Completely physically isolated to avoid contamination
Cross flow heat exchangers can ensure that outdoor air does not come into direct contact with the air inside the data center, avoiding pollution, dust, or humidity affecting IT equipment. They are suitable for data centers with high air quality requirements.
(3) Suitable for various climatic conditions
In dry or warm climates, indirect evaporative cooling systems are particularly effective and can significantly reduce the cooling costs of data centers.
Even in areas with high humidity, optimizing the design of heat exchangers can improve heat exchange efficiency.
(4) Reduce water resource consumption
Compared to direct evaporative cooling (DEC), indirect evaporative cooling does not require direct spraying of water into the air of the data center, but rather indirect cooling through a heat exchanger, thus reducing water loss.
Applicable scenarios
Cross flow heat exchangers are widely used in the following types of data centers:
Hyperscale Data Center: Requires efficient and energy-saving cooling solutions to reduce operating costs.
Cloud computing data center: requires high PUE values and seeks more sustainable cooling methods.
Edge Data Center: typically located in harsh environments, requiring efficient and low maintenance cooling systems.
Challenge and Optimization Plan
Heat exchanger size and efficiency: Larger cross flow heat exchangers can improve heat exchange efficiency, but they also increase the footprint, so optimization design is needed, such as using aluminum or composite material heat exchangers to improve heat exchange efficiency.
Scaling and maintenance: Due to humidity changes, heat exchangers may experience scaling issues, requiring regular cleaning and the use of corrosion-resistant coatings to extend their lifespan.
Control system optimization: Combined with intelligent control, dynamically adjust the working mode of the heat exchanger based on external environmental temperature, humidity, and data center load conditions to improve system adaptability.
Future Development Trends
New efficient heat exchange materials, such as nano coated heat exchangers, further improve heat exchange efficiency.
Combined with AI intelligent control system, dynamically adjust the heat exchange according to the real-time load of the data center.
Combining liquid cooling technology to further improve heat dissipation efficiency in high-density server rooms.

Cross flow heat exchangers play an important role in the indirect evaporative cooling system of data centers, providing efficient heat transfer, reducing energy consumption, minimizing pollution, and improving equipment reliability. They are currently one of the important technologies in the field of data center cooling, especially suitable for large-scale, high-efficiency data centers.

Industrial Heat Recycle Bin Series

Note:

1.Heat from industrial waste gas with exhaust air temperature below 200°C can be recovered to heat fresh air

2. The structure of heat recycle box can be designed according to the site situation.

3. There is no feeding or exhaust fan in this structure.

4. The heat recovery efficiency in this table is equal to the air supply and exhaust volume. You can consult our company for heat recovery efficiency with different air supply and exhaust volume.

5. The heat recovery box can be made into floor type, ceiling type and other structural types (general air volume 100000m%/h to scare).

Commercial Ventilation and Energy Recovery

　　Adequate indoor air quality(IAQ)involves many factors depending on the local situation and climate.Health issues like breathing problems can arise from air containing dust,pollen,or other contaminants.A poor indoor environment can also damage buildings.

　　Commercial(non-residential)air handling units tend to be larger units designed for buildings like offices,hotels,and airports.The challenge is to achieve a comfortable IAQ with as little energy input as possible.This means that pressure drop should be low(less fan power is needed)and thermal/humidity efficiency high(less energy consumed for heating/cooling/humidity control).

　　Depending on the geographical region,the primary purpose of the heat exchanger shifts between heating or cooling(and maybe also dehumidifying)the outdoor air before it enters the building.

　　The air handling unit(AHU)is at the center of a ventilation system.At a minimum,an AHU includes one or several fans in each air channel to move the air through the unit.Filters on either side remove dust,pollen,etc.,and protect the fans.Finally,a heat exchanger transfers the required heat or humidity from the exhaust air to the supply air.

　　Implementing an air-to-air heat exchanger is an excellent way to utilize what is usually considered waste heat.An air-to-air heat exchanger will use the temperature difference between the supply and exhaust air to increase the system’s efficiency.There are two types of air-to-air heat exchangers:rotary and plate heat exchangers.

　　The type and exact configuration depends on the application.Both types are made of aluminum,which has excellent properties such as efficient heat transfer capabilities and an extraordinarily long life span.We offers numerous design variables and options for each product,enabling perfect fit and performance in every AHU.

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