2. 1. 1 make-up water: The water lost from the circulating cooling water system due to evaporation, sewage discharge and wind blowing (splashing) of the cooling tower is called make-up water.
2. 1.2 Evaporation loss: In the open circulating cooling water system, the hot circulating cooling water is evaporated and cooled in the cooling tower, and the water lost in this process is called evaporation loss.
2. 1.3 Wind-blown loss: the amount of water lost when the airflow is brought into the atmosphere from the system during ventilation.
2. 1.4 discharge rate: maintain a certain concentration multiple of water discharge in the system.
2. 1.5 cooling range or temperature drop: the temperature difference between the cooling tower inlet and the sump outlet.
2. 1.6 circulation quantity: the circulating water quantity in the system is a function of time.
2. 1.7 concentration multiple (k): due to the evaporation loss of cooling water in the circulation process, the dissolved salts contained in the water are continuously concentrated in the circulating cooling water system, so that the salt content in the cooling water is higher than that in the make-up water, and the ratio of the two is called concentration multiple.
2. 1.8 system volume: the sum of all water capacities in the open cooling water system, including the effective volume of the cooling tower sump and the water side volume of the system piping and heat exchange equipment.
2. 1.9 Total dissolved solids: the sum of all dissolved substances in water.
2. 1. 10 alkalinity: the sum of bicarbonate, carbonate and hydroxide in water.
2. 1. 1 1 Rs stability index: used to judge the scaling and corrosion trend of water.
2.2 Terminology abbreviation:
2.2. 1 water replenishment rate: m
Evaporation loss: e
2.2.3 wind loss: d
2.2.4 discharge rate: b
2.2.5 cooling range or temperature drop: △T
Cycle: r
2.2.7 concentration multiple: k
2.2.8 system volume: HC
2.2.9 overall solution: TDS
Stability index: i.s.
2.3. Calculation:
2.3. 1 concentration multiple:
K = (conductance or K+ or Na+ in circulating water) ↓ (conductance or K+ or Na+in supplementary water)
2.3.2 Supplementary amount:
M = E × K /(K- 1)
M = B+E+D
Emissions:
B = E÷K×△T
2.3.4 time of each cycle = HC÷R
Evaporation:
E = R×/r
R (latent heat of evaporation) = 573 (kcal/kg) 43℃
574 (kcal/kg) 40℃
577 (kcal/kg) 35℃
2.3.6 Wind loss:
D = R×0. 1%
Large-scale working condition
The circulating cooling water of 135MW cogeneration unit is mainly used for condenser device, and the supplementary water is groundwater and condensed water from the end of steam heater. The purpose of using circulating cooling water is to effectively save water resources and reduce thermal pollution. However, in the process of continuous evaporation and concentration of circulating cooling water, the harmful ions in the water increase exponentially. Coupled with wind and sand, the cooling tower is exposed to the sun for many years outdoors, and dust and debris fall, which will cause scaling, corrosion and microbial growth. The resulting dirt will block the water pipeline, cause corrosion and perforation, reduce heat exchange efficiency and a series of water quality hazards, threatening the normal operation of equipment. In order to prevent scaling and corrosion of equipment and ensure the safe and efficient operation of the system, the water quality of circulating cooling water must be stabilized.
Because the circulating cooling water in thermal power plant has the characteristics of large circulation, high heat medium temperature and single heat exchange material. This scheme is aimed at the characteristics of water quality, on-site process parameters and condenser scaling caused by chemicals used in thermal power plants. Combined with our experience in treating circulating cooling water for many domestic power industries, the treatment scheme suitable for the quality of circulating cooling water in your factory was selected through experiments.
This treatment scheme is formulated according to the water quality and working conditions of circulating water in power plants with medium hardness. This scheme includes the chemical treatment and microbial control agent formula, agent adding method, control index and technical standard of treatment effect for normal operation of circulating cooling water system.