Purchase conditions of cooling tower

1. The specific design parameters of the cooling tower shall be subject to the parameter requirements of the air conditioning host in the design drawing. 

2. It must meet the design requirements of inlet and outlet water temperature, hourly cooling water volume under wet bulb temperature and ultra-low noise indicators. The supplier must provide the equipment model, specification, performance index, external dimension, dry weight, operating weight, noise index and other data calibrated by the manufacturer. 

3. The manufacturing of cooling tower must comply with GB / t7190 1-2008 standard, the main technical requirements are as follows: 

(1) The cooling capacity shall not be less than 95.0%

(2) The measured power consumption ratio shall not be greater than 0.035KW / (m) ³/ h).

(3) The bleaching rate shall not be greater than 0.015% of the nominal cooling water flow

(4) The noise level is ultra-low noise type C, and the nominal cooling water flow is 125 M ³/ H the noise index of the cooling tower shall not exceed 58.0db (a), and the nominal cooling water flow shall be 250m ³/ H the noise index of cooling tower shall not exceed 60.5db (a).

4. Cooling tower body

(1) The cooling tower body is an anti-seismic structure, and the specification, model and thickness of steel used for the structure shall comply with the provisions of relevant standards. All parts shall be subject to hot-dip galvanized surface treatment, and the connecting fasteners shall be stainless steel.

(2) The stiffness of the tower shall meet the requirements of relevant specifications, and shall meet the requirements of seismic fortification intensity of 7 in this area, and its wind resistance strength shall be more than 250kg / m2.

5. FRP parts

(1) It shall be made of glass fiber reinforced plastic (FRP) with corrosion resistance, weather resistance and impact resistance, and it is not allowed to contain talc and other impurities; The imported gel coat layer with good aging resistance and stability shall be adopted on the surface, and its thickness shall be controlled within the range of 0.3-0.5mm; The raw materials used shall comply with the provisions of relevant standards, and the resin content, curing degree, bending strength, Babbitt hardness and other indicators shall fully meet the requirements of the national standard of cooling tower; Flame retardant resin is required to be used, and its oxygen index detection value is ≥ 28. Other materials used on the surface of the tower shall also be flame retardant materials.

(2) The appearance gel coat layer of FRP body shall be uniform, with smooth surface, no crack and uniform color. There shall be no more than 3 bubbles with a diameter of 3-5mm on the outer surface of the tower within 1m2, and bubbles with a diameter of more than 5mm are not allowed. The inner surface of the lower tower shall be a resin rich layer with a resin content of more than 70%; The edge of the tower body shall be neat, the thickness shall be uniform, and there shall be no delamination. The cutting section shall be sealed with resin.

6. Fan

(1) The performance parameters of the fan shall meet the requirements of the design working conditions. The static balance test shall be conducted before the fan assembly, and the blades shall be positioned and numbered after balance.

(2) The matched motor and reducer shall be matched with the fan. The motor is fully enclosed outdoor type, with insulation grade above grade B and protection grade of 1p55 The brand and manufacturer shall be indicated, and the origin of imported motor shall be indicated.

(3) Reducer, shaft, bearing, belt and pulley are required to be high-quality parts, and the product brand, specification, model, material and manufacturer shall be indicated. The place of origin of imported parts shall be indicated.

(4) The fan blade shall have reliable strength, smooth surface, over uniform cross-section and no defects such as crack, notch and burr; On the surface of FRP fan blade, the visible bubble diameter shall not be greater than 3mm, and the number of bubbles in each 100mm area shall not exceed 3.

(5) the clearance between the blade and the inner wall of the air duct shall be uniform, and its value shall not be greater than 0.008 times the fan diameter.

(6) the fan drive bearing shall adopt external oil injection structure to facilitate daily maintenance; A reliable protective net shall be set above the fan to prevent foreign matters from entering the cooling tower.

7. Filler

(1) The cooling tower packing shall be flame retardant materials with high cooling efficiency and low ventilation resistance; It is forbidden to use recycled materials or part of recycled materials.

(2) During the installation of the filler, the gap shall be uniform, the top surface shall be flat, there shall be no collapse and lamination, the filler can bear 2.94kn per square meter, and the filler shall not be empty or broken.

8. Cooling tower water distribution system

(1) The cross flow tower should adopt the pool type water distribution with cover plate.

(2) The distribution tank shall be horizontal, the orifice shall be smooth, and the ponding depth shall not be less than 50mm.

(3) The water distribution shall be uniform.

9. The anti floating structure of the cooling tower shall be easy to load and unload, so as to facilitate the regular cleaning of the cooling tower packing. 

10. The water make-up mechanism of the cooling tower shall be sensitive and reliable.

11. Provide product test reports and meet national inspection standards.

12. The patented technology adopted by the equipment shall have a written description, and the floating water index and energy-saving index shall have a detailed description.

13. The supplier shall provide the following documents with the product:

(1) Samples or product instructions: mainly including design wet bulb temperature, inlet and outlet tower water temperature, cooling water flow, air volume, motor power, standard point noise, main installation dimensions, basic dimensions, foundation load, installation and maintenance instructions; The thermal performance curve calculated according to the thermal test data shall be provided in the product sample or product manual for the user to determine the relevant parameters of the cooling tower under non-standard working conditions.

(2) Factory certificate.

(3) Details of vulnerable parts of the product.

(4) Packing list.

14. The service life of the cooling tower shall not be less than 15 years, and the warranty period is 2 refrigeration periods.