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.
During the drying process of alumina powder, a large amount of high-temperature exhaust gas is generated. If it is directly discharged, it not only wastes heat energy but also increases environmental load. The waste heat recovery and reuse system for drying aluminum oxide powder effectively recovers heat from exhaust gas through a gas stainless steel cross flow heat exchanger, achieving energy-saving and environmental protection goals.
Working principle: The system utilizes a stainless steel cross flow heat exchanger to exchange heat between the high-temperature exhaust gas emitted during the drying process and cold air. The exhaust gas and cold air cross flow in the heat exchanger, and the heat is transferred through the stainless steel plate wall. The cold air is heated into hot air, while the exhaust gas is cooled and discharged.
Program features:
Efficient recycling: The cross flow design has a high heat exchange efficiency, reaching 60% -80%, fully utilizing the waste heat of exhaust gas.
Durable: Made of stainless steel material, it is resistant to high temperatures and corrosion, and suitable for the characteristics of aluminum oxide powder drying exhaust gas.
Widely used: Recycled hot air can be used for preheating raw materials, drying assistance, or heating, reducing energy consumption.
Process description: Drying exhaust gas → Dust removal pretreatment (if necessary) → Stainless steel cross flow heat exchanger → Hot air output → Reuse.
This solution has a compact structure and stable operation, making it a practical choice for recovering waste heat from drying aluminum oxide powder, helping enterprises save energy, reduce emissions, and improve efficiency.
We are a heat exchanger manufacturer from China, specializing in the production of cross flow and counter current heat exchangers, rotary heat exchangers, and heat pipe heat exchangers. We are widely used in boiler flue gas waste heat recovery, heat pump drying waste heat recovery, food, tobacco, sludge, printing, washing, coating drying waste heat recovery, data center indirect evaporative cooling systems, steam condensation to remove white smoke, large-scale aquaculture energy-saving ventilation, mine exhaust heat extraction, and other fields to meet the needs of different customers. If you have a need for air to air heat exchangers, you can contact us. If there is no confirmed product model, we can help you choose the desired model and customize a waste heat recovery solution according to your needs. Looking forward to your contact.
A cross-flow heat exchanger is a type of heat transfer device where two fluids—typically a gas and a liquid or two gases—flow perpendicular to each other. In the context of a cooling tower, this setup is often used to transfer heat from a warm gas (such as exhaust air or process gas) to a cooler medium (like ambient air or water vapor), facilitating efficient cooling. The "aluminum foil material" suggests the heat exchanger’s core is constructed from thin aluminum sheets or foils, which are commonly used due to their excellent thermal conductivity, lightweight nature, and corrosion resistance when properly treated.
Design and Functionality
In a cross-flow configuration for a cooling tower, the gas (e.g., warm air exiting an industrial process) flows horizontally across the exchanger, while the cooling medium (often ambient air drawn in by the tower’s fans) moves vertically or in a perpendicular direction. The aluminum foil forms the heat transfer surface, typically arranged as plates or fins. These foils create channels that keep the two streams separate, preventing mixing while allowing heat to transfer through the conductive aluminum. The thinness of the foil maximizes surface area for heat exchange while keeping the unit compact.
For cooling tower applications, the exchanger could be integrated into the tower’s air intake or exhaust system. The goal is often to pre-cool the gas before it interacts with the tower’s water-based cooling mechanism or to recover heat from the exhaust for energy efficiency. Aluminum’s thermal conductivity (around 237 W/m·K) ensures efficient heat transfer, and its foil form allows for a high surface-area-to-volume ratio, enhancing performance.
Advantages of Aluminum Foil Material
Lightweight and Cost-Effective: Aluminum foil reduces the overall weight and material cost compared to thicker metal constructions.
Corrosion Resistance: When coated (e.g., with hydrophilic or epoxy layers), aluminum resists corrosion from moisture or chemicals common in cooling tower environments.
High Efficiency: Thin foils increase heat transfer efficiency, though they may trade off some pressure drop, depending on channel spacing.
Application in Cooling Towers
In a cooling tower, a cross-flow gas heat exchanger might serve purposes like:
Heat Recovery: Capturing heat from exhaust gas to preheat incoming air or water, reducing energy costs.
Pre-Cooling: Lowering the temperature of incoming gas to improve the tower’s evaporative cooling efficiency.
Compact Integration: Fitting into space-constrained tower designs due to the foil’s thin profile.
A typical efficiency for a cross-flow heat exchanger ranges from 40-65%, though this depends on factors like flow rates, temperature differences, and foil spacing. For higher efficiency (up to 75-85%), a counter-flow design might be considered, but cross-flow is often chosen for its simplicity and lower cost in cooling tower setups.
Wind power is a kind of clean energy, with the characteristics of renewable, pollution-free, large energy and broad prospects. The development of clean energy is the strategic choice of all countries in the world.
However, if the air is directly fed into the generator cabin for cooling, the dust and corrosive gas will be brought into the cabin (Especially wind turbines installed offshore).
Indirect cooling system solution
The indirect cooling method can make the air from inside and outside perform indirect heat exchange to achieve the effect of cooling the wind generator cabin without bringing dust and corrosive gases from outside into the cabin.
The main component of the indirect cooling system is the BXB plate heat exchanger. In the BXB plate heat exchanger, two channels are separated by aluminum foil. The air in the cabin is closed circulation, and the outside air is open circulation. The two airs are doing heat exchange. The air in the cabin transfers heat to the outside air, which reduces the temperature in the wind generator. In addition, the air inside and outside the cabin will not be mixed due to the isolation of aluminum foil, which prevents dust and corrosive gases outside the cabin from being brought into the cabin.
Cooling effect analysis
Taking a 2MW unit as an example, the motor's heat generation is 70kW, The circulating air volume in the engine room is 7000m3/h and the temperature is 85℃. The outside circulating air volume is 14000m3/h and the temperature is 40℃. Through the BXB1000-1000 plate heat exchanger, the air temperature in the cabin can be reduced to 47℃ and the heat dissipation capacity can reach 72kW. The relevant parameters are as follows:
At present, the utilization rate of air conditioning in public places, more and more people in a closed environment for a long time, because of the lack of the necessary air flow, indoor air quality is very poor, easy cause fatigue unwell and the spread of disease, therefore, measures must be taken for air exchange, using fresh air ventilation with heat recovery unit make the fresh air and exhaust air heat exchange equipment, can be very good to solve this problem.
Current status of air quality in public places:
1. Poor ventilation;
2. Large flow of people, more pollution sources, poor indoor air quality;
Measures:
The introduction of fresh air, "Public Health indicators and Limits requirements" for fresh air volume put forward clear requirements.
Causing problems:
Introduce a large number of fresh air, direct discharge of indoor air, resulting in a large waste of energy;
How to solve:
The fresh air ventilation equipment with heat recovery device makes heat exchange between fresh air and exhaust air, which not only effectively improves indoor air quality, but also solves a large amount of energy waste.
Schematic diagram of heat recovery fresh air ventilation equipment
New air volume recommended table for comfortable air-conditioned rooms
Medical treatment, biopharmaceutical and high-end electronic intelligence industries have emerged as the country's large-scale industrial strategy, and these industries cannot be separated from the application of purification systems. Because of the particularity of the purification system, the introduction of fresh air and the discharge of some indoor air are realized by power, so the demand for energy is fixed. In the system without new and exhaust energy recovery devices, fresh air will consume a lot of energy, while the energy in exhaust air will be wasted. If the energy in exhaust air can be recovered and the fresh air can be pre-cooled or preheated, the waste of resources can be reduced to the maximum extent. The system mode of strong delivery and strong exhaust is more conducive to the arrangement and utilization of new and exhaust energy recovery.
In the air conditioning system design of major hospitals, treatment centers and animal laboratories, in order to avoid cross pollution, the distance between new fans and exhaust fans is usually relatively far. Our company can provide liquid circulating energy recovery scheme. This energy recovery method can effectively avoid cross-contamination of fresh and exhaust air, effectively recover the cold heat in exhaust air through liquid circulation, and release the recovered energy into fresh air, so as to achieve the purpose of reducing energy consumption of fresh air. This recovery system can drag one or more modes.
In the process purification site, in order to ensure the purification level of the confined space, these areas are relatively independent and closed. In order to maintain the oxygen content of the air in these areas, the supply of fresh air must be increased to a certain proportion. In this case, air-conditioning systems and plate, wheel or heat pipe energy recovery devices can be used.
With the advent of the 5G big data era, network evolution and the rapid development of the data industry, the scale of large data centers(DC) is getting larger and larger, and the power consumption of data centers is also increasing. According to statistics, the national DC electricity consumption in 2018 was 160.889 billion kW/h, surpassing Shanghai's total electricity consumption in 2018, accounting for 2.35% of China's total electricity consumption. Moreover, It is expected to reach 266.792 billion kW/h in 2023, The average annual growth rate will reach 10.64%, which is approximately equal to the power generation capacity of 2.5 Three Gorges.
More importantly, power consumption has become a bottleneck restricting the development of data center services. The following table shows the proportion of energy consumption of each system configuration in the data center. From the analysis of the data in the table, it can be found that in the non-IT energy consumption, about 63% of the loss is caused by the data center cooling system.
In response to the high energy consumption of the data center cooling system, various energy-saving solutions have been tried in the industry. At the result, Indirect Evaporative (IEC) is one of the most promising cooling solutions.
The following figure shows the working principle diagram and product structure diagram of indirect evaporative cooling system.
The indirect evaporative cooling system mainly includes three core components: plate heat exchanger, spray system, and compressor supplementary cooling system. During the cooling process, the air to be treated inside the data center passes through the air heat exchange device. Firstly, the outdoor air is used to cool the closed indoor air. At the same time, the spray system spray water uses the heat of the outdoor air to evaporate in the plate heat exchange device. Absorb heat to reduce the temperature of the air to be processed. As the result, making cool the circulating air inside the DC to the greatest extent. Throughout the process, indoor air is a closed loop system, while outdoor air is an open system. Outdoor air does not allow enter the DC, thus preventing moisture and pollutants in the outdoor air from entering the DC. Since the treated air does not directly contact with water, its moisture content remains unchanged, realizing isohumid cooling of air.
Operating mode
Depending on the outdoor temperature, the Evaporative Cooling Air-conditioning can adopt three operating modes.
Taking a single set of system (selecting BXB2000-2200-12.0 plate heat exchanger) as an example, the selection calculation shows that compared to a pure refrigeration and air-conditioning system, adopting an indirect evaporative cooling system. The air sensible plate heat exchanger can recover 194kw per hour. Spray system can absorb 686kw of heat, and recover a total of 880kw of heat. It can be seen that the use of an indirect evaporative cooling system can save 352kw*h of electricity per hour for the evaporative cooling system, and the energy saving effect is significant.
With the further development of China's economy, the use of green energy will be more and more extensive. Heat pump dehumidification dryers with plate type obvious heat recovery function have developed rapidly in recent years and have been widely used in the Yangtze River basin, southwest China and South China.
The unit using the inverse cano principle at the same time, combined with efficient heat recovery technology, in the whole drying dehumidifying process, through the duct the wet air within the chamber connected to the host using the sensible heat plate heat collector recovery of the sensible heat and latent heat of hot and humid air, thermal recycling, greatly improve the performance of the host, improve the drying speed and material quality. The waste heat can not only improve the performance of the unit, but also reduce the thermal pollution to the environment and alleviate the urban heat island effect.
The heat pump drying heat recovery system is not only used in the mud drying system, but also widely used in many other drying industries. It has the characteristics of good drying quality and high degree of automation, and is the best choice product for energy saving, green and environmental protection in the modern drying industry.
Heat pump dryers with and without heat recovery working principle
When the heat pump dryer dries the air, the air forms a closed cycle between the drying chamber and the equipment. The evaporator's heat absorption function is used to cool and dehumidify the hot and humid air, and the condenser's heat release function is used to heat the dry cold air, so as to achieve the effect of cycle dehumidification and drying.
The main difference between heat recovery function and heat pump dryers without heat recovery function lies in the different air circulation modes. The former is equipped with plate type sensible heat exchanger, which plays the function of pre-cooling and preheating in the air circulation process, reducing the load of compressor operation and achieving the purpose of energy saving.
Heat pump drying system operation mode
Energy saving analysis of heat recovery
Taking a heat pump dryer as an example, the air temperature of drying is designed to be 65℃, the relative humidity is 30%, the circulating air temperature is 65℃, the temperature before passing through the evaporator is 65℃, and the temperature after evaporation cooling is 35℃. The condenser needs to heat the air of 35℃ to 65℃ before it can be used.
After matching with BXB500-400-3.5 heat exchanger, 35℃ return air absorbs heat from exhaust air after passing through plate heat exchanger, and the temperature rises to 46.6℃. The condenser only needs to heat the air from 46.6℃ to 65℃ to meet the use requirements, greatly reducing the load of evaporator and condenser, thus reducing the power of the whole machine, achieving the purpose of energy saving.
Energy saving analysis of heat recovery
Selection and economic calculation
We are very glad to show you the calculation and selection software of plate heat exchanger jointly developed by us and Tsinghua University. If you need, please contact us!
The main components of the air to air waste heat recovery system are heat exchangers (including cross flow, counter flow, rotary, and heat pipes). Cross flow heat exchangers are mainly made of materials such as aluminum foil, stainless steel foil, or polymer PP. 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.
We are a heat exchanger manufacturer from China, specializing in the production of cross flow and counter current heat exchangers, rotary heat exchangers, and heat pipe heat exchangers. We are widely used in boiler flue gas waste heat recovery, heat pump drying waste heat recovery, food, tobacco, sludge, printing, washing, coating drying waste heat recovery, data center indirect evaporative cooling systems, steam condensation to remove white smoke, large-scale aquaculture energy-saving ventilation, mine exhaust heat extraction, and other fields to meet the needs of different customers. If you have a need for air to air heat exchangers, you can contact us. If there is no confirmed product model, we can help you choose the desired model and customize a waste heat recovery solution according to your needs. Looking forward to your contact. Manager Yang, kuns913@gmail.com ， WhatsApp：+8615753355505
