Greenhouse Heating Project Plan for Four 20-ton Biomass Chain Grate Hot Water Boilers

 1. Overview of heat consumption in vegetable greenhouses

The vegetable greenhouse adopts the central heating mode, the annual heating cycle is four months, the heating temperature is 15-18 degrees, the construction area of ​​a single greenhouse is 4800m2, the total number of greenhouses is 158, the total construction area is 760000m2, and the heat load per unit area of ​​the vegetable greenhouse is 70W/m2 , The total heat load is 54MW.

4 Sets of 14mw Biomass Chain Grate Hot Water Boiler

2. Overview of the heating scheme for vegetable greenhouses

1. Choice of heating method

According to the requirements of vegetable varieties and temperature in the vegetable greenhouse, the heating mode of hot water heater and geothermal pipe is adopted. The temperature adjustment of this heating mode is sensitive, stable and reliable. The corresponding temperature range can be set for different types of vegetables, and the temperature adjustment range is balanced. , the temperature deviation is small. The greenhouse heating method needs to be designed and arranged according to the structure of the greenhouse.

2. Selection of biomass boiler heating equipment

According to the above heating characteristics and heat supply demand of vegetable greenhouses, it is proposed to build four 14MW biomass chain grate hot water boilers to provide centralized heating for vegetable greenhouses. The boiler room can be planned once and built in stages according to the project progress. The boiler adopts a single drum, balanced ventilation and full forced flow water circulation mode, steel structure factory building, and indoor layout.

1) Basic characteristics of biomass hot water boiler:

⑴Rated thermal power: 14MW

⑵Rated outlet pressure: 1.25MPa

(3) Rated outlet water temperature: 115°C

⑷Drum working pressure: 1.305MPa

⑸Rated inlet water temperature: 70℃

⑹Circulating water volume: 277t/h

⑺Boiler design efficiency: 82%

⑻ Average low calorific value of biomass pellets: 15.99MJ

⑻ Average fuel consumption: 4000kg/h

The raw materials are wood pellets, peanut husks, and corn husks. The elemental analysis and industrial analysis of representative design fuels are shown in the table below.

The fuel composition is as follows: wood pellets (dry basis)

Peanut shells (dry basis)

2) Main indicators of boiler economical operation:

⑴Exhaust gas temperature: 150℃

⑵Excess air coefficient at furnace outlet: 1.05

⑶excess air coefficient at the smoke exhaust: 1.4

⑷The actual operating efficiency of the boiler: >82%

3) Basic size of biomass circulating fluidized bed boiler :

Elevation of drum center: 8800mm

Elevation of boiler operation floor: 0mm

3. Biomass boiler equipment list