Heating of drying medium: In the drying process of chemical materials, it is necessary to heat the drying medium (such as air, nitrogen, etc.) to a certain temperature to improve the drying efficiency. Heat pump heat exchangers can elevate the temperature of thermal energy or industrial waste heat in the environment and use it to heat drying media. For example, when drying pesticide intermediates, a heat pump heat exchanger is used to heat the air and raise the air temperature to 60-80 ℃, providing the required heat for the drying process. Compared with traditional electric or gas heating methods, it can significantly reduce the drying cost.
Recycling of waste heat from drying exhaust gas: The exhaust gas emitted during the drying process of chemical materials usually contains a certain amount of heat and moisture. If directly discharged, it will cause energy waste and environmental pollution. A heat pump heat exchanger can cool dry exhaust gas, recover its heat, and condense the moisture in the exhaust gas, achieving the goal of waste heat recovery and energy conservation and emission reduction. The recovered heat can be used to preheat fresh drying media or other processes, improving energy utilization efficiency.
The role of heat pump heat exchangers in the chemical industry
1. Maintain reaction temperature: Many chemical reactions require specific temperature ranges to ensure reaction rate and product quality. The heat pump heat exchanger can adjust the temperature inside the reaction vessel to timely remove or supplement the required heat generated by the reaction, so that the reaction can proceed under stable temperature conditions. For example, in the polyester synthesis reaction, it is necessary to strictly control the reaction temperature at around 200-250 ℃. The heat pump heat exchanger can accurately adjust the temperature of the reaction kettle to ensure the smooth progress of the reaction.
2. Recycling reaction waste heat: Some chemical reactions are exothermic reactions, and if the large amount of waste heat generated is not utilized, it will not only cause energy waste, but also may cause thermal pollution to the environment. Heat pump heat exchangers can recover the heat from high-temperature hot water or steam discharged from the reaction kettle, raise it to a higher temperature level, and use it for other processes that require heat, such as preheating reactants, heating process water, etc., thereby improving the energy utilization efficiency of the entire chemical production process.
What industrial fields are heat pump heat exchangers used in?
Process heating in industrial production: In some industrial production processes that do not require particularly high temperature but require a large amount of heat energy, such as food processing, textile printing and dyeing, wood drying, etc., heat pump heat exchangers can use industrial waste heat or environmental heat energy to provide the required heat for the production process, achieving energy recovery and energy conservation and emission reduction.
Industrial wastewater waste heat recovery: Many industrial production processes generate a large amount of wastewater, which often contains a certain amount of heat. Heat pump heat exchangers can extract heat from wastewater and use it to preheat production water or other processes that require thermal energy, reducing energy consumption and production costs for enterprises.
Application of waste heat recovery refrigeration in the chemical industry
During the chemical production process, a large amount of waste heat is generated, such as heat dissipation from reaction vessels and exhaust gas from distillation towers. The refrigeration system driven by industrial waste heat can recover and convert this waste heat into cold energy, which can be used for cooling, crystallization, separation and other processes of chemical products. For example, in urea production, the high-temperature gas discharged from the synthesis tower is recovered through a heat exchanger to drive an absorption refrigeration system, providing cooling capacity for the crystallization of urea solution and improving product quality and production efficiency.
Several schemes for recovering waste heat from drying of shaping machine
During the working process of the molding machine, a large amount of high-temperature exhaust gas is generated during the drying stage, which carries a large amount of heat energy and is the main source of waste heat recovery. Generally speaking, the exhaust gas temperature emitted by the shaping machine is around 150 ℃ -200 ℃, which has high recycling value.
Several schemes for recovering waste heat from drying of shaping machine
Heat exchanger recovery: This is the most common method of waste heat recovery. By installing a heat exchanger, high-temperature exhaust gas can exchange heat with cold air or cold water, which can be reused in the drying process of the molding machine or other places that require heat energy. The plate heat exchanger we produce has the advantages of high heat transfer efficiency and compact structure, which can effectively transfer the heat in the exhaust gas to the medium that needs to be heated.
Heat pipe recycling: Heat pipes are efficient heat transfer components. In the waste heat recovery of the shaping machine, one end of the heat pipe is placed in the high-temperature exhaust gas to absorb the heat of the exhaust gas, and the other end is placed in the medium that needs to be heated to release the heat. Heat pipe recovery technology has the characteristics of fast heat transfer speed and low heat loss, which can achieve long-distance heat energy transmission and recovery.
Heat pump recycling: Heat pump technology can convert low-temperature heat energy into high-temperature heat energy for heating needs in production or daily life. In the waste heat recovery of the shaping machine, the heat pump can extract the low-temperature heat energy from the exhaust gas, and through compression, condensation and other processes, raise the heat energy to a higher temperature, and then use it for drying, heating water and other purposes. The advantage of heat pump recycling technology is that it can effectively utilize low-grade heat energy and achieve significant energy-saving effects.
U Shape Dehumidification Heat Pipe Unit
A U-shape dehumidification heat pipe unit is a specialized component used in air conditioning and dehumidification systems to enhance efficiency by pre-cooling and reheating air. Below is a concise overview, addressing its function, medium, and characteristics, within 200 words:
Function
The U-shape heat pipe unit facilitates dehumidification by transferring heat without external power. It cools incoming humid air at the evaporator end, causing moisture to condense, then reheats the drier air at the condenser end, improving comfort and reducing energy use. The U-shape design fits compactly into HVAC systems or dehumidifiers.
Working Medium
The heat pipe is typically filled with:
- Refrigerants: R134a or R410A are most common, effective in 0-60°C ranges, offering high heat transfer for residential and commercial units. R32 is used in newer, eco-friendly systems.
- Water: Occasionally used for mid-temperature (30-100°C) industrial applications, leveraging high latent heat.
- Ammonia: Rare, for low-temperature (-50 to 50°C) systems like cold storage.
The medium operates in a vacuum-sealed tube, evaporating at the hot end and condensing at the cold end, with a wick (e.g., sintered metal) ensuring fluid return.
Characteristics
- Efficiency: Boosts dehumidification by 20-30% without extra energy.
- Compactness: U-shape optimizes space in tight units.
- Durability: Corrosion-resistant materials (e.g., copper or aluminum) ensure longevity.
Summary: U-shape dehumidification heat pipes, usually filled with R134a/R410A, enhance energy-efficient moisture control.
U-tube heat exchanger
A U-tube heat exchanger is a common shell-and-tube device named for its U-shaped tube bundle, widely used in chemical, petroleum, and energy industries. It consists of U-tubes, a shell, and tube sheets, with hot fluid flowing inside the tubes and cold fluid in the shell, facilitating heat transfer. The U-shape allows tubes to expand freely, accommodating high temperatures and pressures while reducing thermal stress. Advantages include simple design, easy maintenance, and high heat transfer efficiency, ideal for clean or moderately corrosive fluids. However, tube cleaning is challenging, and it requires more space. U-tube heat exchangers excel in steam condensation and liquid heating processes.
microchannel heat exchanger
A microchannel heat exchanger is a highly efficient, compact device used in refrigeration, air conditioning, automotive, and renewable energy sectors. Its core feature is a microscale channel structure that greatly increases the heat transfer area, enhancing efficiency. Compared to traditional heat exchangers, it’s smaller, lighter, and offers superior heat transfer with less refrigerant, making it energy-saving and eco-friendly. Typically made of aluminum alloy, it’s corrosion-resistant and easy to process. Common designs include parallel-flow and cross-flow, ideal for high heat flux scenarios. Despite higher manufacturing costs, its efficiency and compactness make it popular, especially for EV battery cooling and data center thermal management.
graphite heat exchanger
A graphite heat exchanger is a type of heat transfer equipment made from graphite, widely used in industries like chemical processing, pharmaceuticals, and metallurgy for handling corrosive media. Graphite offers excellent corrosion resistance, high-temperature stability, and good thermal conductivity, making it ideal for harsh environments involving acids, alkalis, and other aggressive substances.
Graphite heat exchangers come in various designs, including tubular, plate, and block types. Tubular designs suit high-temperature and high-pressure conditions, plate types offer high heat transfer efficiency, and block types are compact and easy to maintain. They work by transferring heat from one medium to another through graphite, while maintaining the chemical stability of the media.
Advantages include:
- Corrosion resistance: Suitable for diverse chemical environments.
- High thermal conductivity: Efficient heat transfer.
- Long lifespan: Durable graphite material.
Drawbacks include graphite’s brittleness, which limits mechanical shock resistance, and relatively high manufacturing costs. Graphite heat exchangers are commonly used in applications like chlor-alkali production and sulfuric acid processing, making them ideal for complex chemical processes.
Energy Recovery Ventilator (ERV)
An Energy Recovery Ventilator (ERV) is a mechanical ventilation system that exchanges stale indoor air with fresh outdoor air while recovering both heat and humidity from the outgoing air stream. It’s designed to improve indoor air quality and energy efficiency, especially in well-sealed buildings.
How It Works
An ERV system uses a heat exchanger core, usually made from a semi-permeable membrane or specially designed material, to transfer sensible heat (temperature) and latent heat (moisture) between incoming and outgoing air streams. This exchange occurs without mixing the air, ensuring clean and efficient ventilation.
-
In winter: Warm, humid indoor air preheats and humidifies the incoming cold, dry outdoor air.
-
In summer: Cool, drier indoor air pre-cools and dehumidifies the incoming warm, moist air.
Key Components
-
Supply and exhaust fans: Pull fresh air in and push stale air out.
-
Heat exchanger core: Allows energy transfer (heat and humidity) between air streams.
-
Filters: Clean incoming and outgoing air to remove dust, pollen, and pollutants.
-
Controls: Manage airflow rate, timers, and integration with HVAC systems.
Benefits of ERV Systems
-
Improved indoor air quality: Constant fresh air flow reduces CO₂, VOCs, and odors.
-
Energy savings: Recovers up to 60–80% of heat and moisture energy that would otherwise be lost.
-
Humidity control: Helps maintain a comfortable indoor humidity level year-round.
-
Balanced ventilation: Equal supply and exhaust airflow reduces pressure imbalances in the building.
-
Longer HVAC life: Reduces load on heating and cooling equipment.
Common Applications
-
Residential homes
-
Office buildings
-
Schools and universities
-
Hospitals and healthcare facilities
-
Energy-efficient or airtight buildings (e.g., Passive House)
Considerations for Installation
-
Proper sizing is essential (based on square footage and occupancy).
-
Needs ducting and potential integration with HVAC system.
-
Regular maintenance required: filters and exchanger core need cleaning/replacement.