In 1992, the Chinese Academy of Agricultural Engineering Research and Planning was requested by the Ministry of Agriculture to set a National Standard for testing household cooking and heating coal stoves. Institutes and stove manufacturers were required to test the thermal performance of products and to improve the quality of the stoves so that they meet set requirements.
- Water flows through the heating system without a water pump or electricity. This is especially useful in regions that use the stoves but are without electricity (Figure 1).
- The heating system is simple and can be operated and maintained with ease.
- The average temperature of water in the radiators is around 70°C. This makes people feel comfortable.
- When the stove is closed during the night, the water in the heating system is still flowing slowly. The room temperature therefore does not drop too steeply.
- The stoves can also provide hot water for baths.
Model AIYI High Efficiency Household Stove is a patent product that was designed and developed by the AIYI Development Corporation, Beijing, China (Figure 2). It is designed to optimize conduction, radiation and convection using heat transfer principles. This product has the following advantages:
- High efficiency and large capacity. When compared to ordinary stoves, it saves about one ton of coal for each family for a winter in northern China.
- Good thermal insulation.
- The system is clean. The coal is held in a closed inner compartment, so that the kitchen environment can be kept clean without dust from the stove.
- Long lasting. The water tank is made of thin cast iron that transfers heat quickly. It has a good resistance to water erosion and high temperature. The life of this type of water tank is two to three times longer than its equivalent made of steel plate.
- The stove must be durable and convenient to use.
- It must last for more than five years.
- No smoke must escape from the stove when it is either on or off.
- Cooking and heating stoves must have the following performance:
- Temperature increase of the water in the heating pipes with the stove open during the day must increase by at least 0.8°C/min
- Available power for cooking ≥1.0kW
- Temperature increase of the water in the heating pipes with the stove closed at night must be less than 0.8°C/min
- Efficiency of stove without cooking facility ≥ 55%
- Efficiency of stove with cooking facility ≥ 50%.
The stove described above was tested by the Testing and Supervising Centre on Firewood & Coal Saving Stoves, Ministry of Agriculture, China, and is considered to be an advanced and practical product.