1 Timely maintenance

Inspections of frozen cold biogas facilities include pipeline maintenance, ongoing biogas digester inspections, and new biogas digester overhauls.

1.1 Pipeline Maintenance

Under freezing weather conditions, condensation can easily form in pipelines, even leading to ice blockages. In such cases, the gas valve should be opened, and if the pressure gauge pointer is shaking violently or water sounds are heard within the pipes, condensation should be promptly drained to prevent blockages.

Outdoor pipelines that are not buried underground or insulated with straw ropes, rags, or plastic films are prone to cracking due to freezing. It is essential to replace them promptly.

Outdoor pipelines are prone to falling due to freezing, and aging pipes are susceptible to cracking, while joints are prone to loosening. Timely replacement is necessary.

During the maintenance of the biogas digester, a sudden drop in temperature occurred, which is prone to cause cracking of the pool walls, especially in areas such as the water pressure box, water storage ring, and feed-in room. Pressure testing revealed cracks in the pool walls. Repairs were conducted in accordance with the "Management and Operation Procedures for Rural Household Biogas Digesters." The pool was emptied and cleaned, and all safety measures were in place before reapplying the sealant mortar. Generally, a "one ash and two pastes" or "two ashes and three pastes" method is adopted.

1.3 New Biogas Digester Inspection

The newly completed pond is prone to cracking if protective measures are not taken. It should be re-inspected and pressure tested. In case of cracks, repairs should be made according to the "Management and Operation Procedures for Rural Household Biogas Ponds," and the sealant mortar should be reapplied.

1.3.2 Incomplete new pond: inspect the concrete for freezing weather curing. If it does not reach the required strength, it should be knocked down and reconstructed. During biogas pond construction, the average daily temperature should be above 10°C.

2 Timely activation of biogas digester

Prior to the impending frozen disaster, it is essential to timely activate the biogas digester to prevent freezing. Technical points:

2.1 An average daily temperature above 15°C allows for the activation of the new biogas digester during sunny midday hours.

2.2 Stock up on raw materials. An 8m...³The biogas digester is preparing 4000kg of manure, rich in nitrogen, and fermentation liquid with a concentration of around 10%. If稻草 or other materials are used as fermentation substrates, they can be mixed with fresh pig, cow, or sheep manure at a 1:1 ratio, or 20kg of carbon ammonia and other materials can be added to narrow the carbon-nitrogen ratio difference, accelerate the reproduction of methane bacteria, and promote gas production.

2.3 Added 1200 kg of sufficient inoculum and old biogas sludge and slurry.

Add a sufficient amount of hot water, ensuring the temperature is above 15°C.

3 Enhance daily management

3.1 Thoroughly mix the liquid in the biogas digester every 3 to 4 days to prevent the formation of crusts and layers.

3.2 Timely addition of fresh raw materials, especially animal and human feces, and distiller's grains.

3.3 Timely Major Feed Change in Line with Agricultural Fertilizer Requirements: Conducting a major feed change in a timely manner allows for the extraction of two-thirds of the feedstock for fertilization, followed by the addition of an equivalent amount of fresh raw materials.