RU2486422C2 - Water reuse system with application of cooling towers - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: water reuse system with application of cooling towers comprises cooling towers connected to each other by hydraulic circuits of water preparation and consumption, cooling towers have separate hydraulic circuits of water preparation and consumption, comprising a body, in the lower part of which there are at least two tanks for collection of water, which are connected to each other by a compensation pipe, which provides for hydraulic independence of working water preparation and consumption circuits. One tank is connected with a pump that supplies water cooled in the cooling tower to a load, and water again arrives through a valve along the pipeline into the second tank, from which the water heated with the pump via the filter and the valve is supplied along the pipeline into a header with nozzles arranged in the upper part of the cooling tower body, and in the section between the filter and the valve there is a system of control of hydraulic resistance of the filter, comprising a pressure gauge and a valve.

EFFECT: cooling tower performance improvement.

2 cl, 2 dwg

Description

The invention relates to contact coolers, in particular to cooling towers, and can be used at thermal power plants for cooling circulating water. The proposed tower can also be used in air conditioning in civil engineering for cooling condensers of refrigeration units, less often - for cooling emergency power generating sets of high power; in the industrial sector, cooling towers are used in technological operations of a wide profile, requiring efficient and non-energy-intensive heat dissipation created during the operating cycle of compressor plants, refrigeration machines and stations, metallurgical industries, plastic molding machines, chemical cleaning of substances, and restoration of pure chemical solvents.

The closest technical solution to the claimed object is a solution for A. with. USSR No. 435442, C02B 1/10 dated 04.07.72, including a water recycling system using cooling towers interconnected by hydraulic circuits for the preparation and consumption of water (prototype).

The disadvantage of this method is the relatively low efficiency due to the low degree of atomization of the liquid by nozzles and uneconomical due to water overruns due to the absence of a plate sprinkler and a droplet eliminator.

The technical result is an increase in the performance of the tower.

This is achieved by the fact that in a recycled water supply system using cooling towers interconnected by hydraulic circuits for preparing and consuming water, each of the interconnected cooling towers contains a housing, in the lower part of which there is a tank for collecting water with a water recharge system for evaporation, which is connected to a pump supplying the water cooled in the cooling tower to the consumer through the filter, and in the area between the filter and the consumer, a filter hydraulic resistance control system is installed RA consisting of pressure gauge and valve.

Figure 1 shows a diagram of a circulating water supply system using cooling towers for one consumer; figure 2 shows a diagram of a circulating water supply system with cooling towers having separate hydraulic circuits for the preparation and consumption of water.

The water recycling system using cooling towers contains cooling towers interconnected by hydraulic circuits for the preparation and consumption of water. For one consumer (Fig. 1), the system includes a cooling tower body 1, in the lower part of which there is a tank 2 for collecting water with a recharge system 3 of water used for evaporation. The tank 2 is connected to the pump 6, which supplies the water cooled in the cooling tower to the consumer 8 through the filter 7. In the area between the filter 7 and the consumer 8, a filter hydraulic resistance control system is installed, consisting of a pressure gauge 9 and a valve 10. After heating the water in the consumer 8, it again enters through valve 11 through pipeline 4 to the manifold 5 with nozzles located in the upper part of the tower body. The water is cooled by a counter flow of air coming in counterflow from below and the cycle of the heat and mass transfer process is repeated.

The reverse water supply system with cooling towers having separate hydraulic circuits for preparing and consuming water (FIG. 2) includes a cooling tower housing 1 (a variant with several parallel connected cooling towers is possible - not shown in the drawing), at least at the bottom of which two tanks for collecting water: tank 2 and tank 12 with a recharge system 3 of water used for evaporation. Tanks 2 and 12 (containers) are interconnected by a compensation pipe, which provides hydraulic independence of the circuits for the preparation of working water and its consumption.

The tank 2 is connected to the pump 6, which supplies the water cooled in the cooling tower to the consumer 8. In the area between the pump 6 and the consumer 8, a system for monitoring the hydraulic resistance of the system is installed, consisting of a pressure gauge 9 and valve 10. After heating the water in consumer 8, it again enters through the valve 11 through a pipeline 4 to a second tank 12, from which heated water by a pump 13 through a filter 7 and a valve 17 is fed through a pipeline 14 to a manifold 5 with nozzles located in the upper part of the tower body.

The water is cooled by a counter flow of air coming in counterflow from below, and the cycle of the heat and mass transfer process is repeated. In the area between the filter 7 and the valve 17, a hydraulic resistance control system for the filter 7 is installed, consisting of a pressure gauge 16 and a valve 15.

The water recycling system using cooling towers works as follows.

The cooling effect in the tower is achieved by evaporating 1% of the water circulating through the tower, which is sprayed by nozzles 5 and flows into the tank in the form of a film through a complex system of irrigation channels to meet the flow of cooling air pumped by fans (not shown in the drawing). An effective droplet separator reduces water loss due to drip entrainment. The amount of droplet moisture carried away by the air flow depends on the irrigation density and at a maximum value of 25 m ³ / (h · m ² ) does not exceed 0.1% of the volumetric flow rate of the cooled water through the cooling tower.

One of the important points for the most efficient use of cooling towers in a water circulation system is the optimal choice of hydraulic connection circuit diagrams. Hydraulic circuit diagrams may vary depending on the number of cooling towers used in one circuit, as well as on the nature of the consumer. The range of regulation of cooling tower performance is determined by the nature of the consumer. The simplest hydraulic circuit of an individual tower used for one service site is shown in FIG. Water from tower 1 enters tank 2, from where it is supplied to consumer 8 by a circulation pump 6 and then to tower 1. In the field of industrial construction, especially when the water flow circulating through the consumer cooler is noticeably less than the water flow circulating through the cooling tower, the scheme shown figure 2. Here, the return water from consumers 8 is settled in storage tanks (tanks) 2 and 12, the volume of which is calculated for about 5-10 minutes of operation of the installation. From it, the pump 13 (pumps) of the working fluid preparation circuit pumps water to the evaporative cooling towers 1. From the cooling tower, the cooled water enters a similar bath (tank). The main distinguishing feature of such a scheme is the hydraulic independence of the circuits for the preparation of working water and consumption, provided by the presence of a compensation pipe between the tanks (tanks). One container with a partition providing overflow between its parts can also be used. As a result of this, it is absolutely not necessary to constantly adjust the power of the cooling towers in accordance with the requirements of the user. Cooling tower fans can simply operate on / off. In addition, each such cooling tower always works at full load and provides the maximum possible cooling of water for given weather conditions. Both circuits are not sensitive to frost, since the cooling towers are completely drained into storage tanks installed indoors or located underground.

In winter, the operation of cooling towers can be complicated due to the freezing of their structures, especially this applies to cooling towers located in harsh climatic conditions. Freezing of cooling towers can lead to an emergency condition, causing deformation and collapse of the irrigator due to additional loads from the ice formed on it. Freezing of the tower usually begins at outdoor temperatures below -10 ° C and occurs in places where the cold air entering the tower comes in contact with a relatively small amount of warm water. Internal icing of the cooling tower is dangerous because, due to intense fogging, it can only be detected after the sprinkler is destroyed. Therefore, in the winter period one should not allow fluctuations in thermal and hydraulic loads, it is necessary to ensure an even distribution of the cooled water over the area of the irrigator and not to allow a decrease in the density of irrigation in individual areas. Due to the high incoming air velocities, the irrigation density in the fan cooling towers in winter is advisable to maintain at least 10 m3 / m2 (at least 40% of the total load). The criterion for determining the required air flow rate can serve as the temperature of chilled water. If the flow rate of the incoming air is adjusted so that the temperature of the chilled water is not lower than + 12 ÷ + 15 ° С, then the icing of the cooling towers usually does not go beyond the permissible limits. Reducing the flow of cold air into the cooling tower can be achieved by turning off the fan or transferring it to work with a reduced speed. It is possible to exclude icing of cooling towers by supplying all water to only part of the cooling towers with complete shutdown of the others, sometimes with a decrease in the flow of circulating water. Discharge fans are subject to frost. This can be caused by two reasons: water droplets falling on the fan from the inside of the cooling tower and recirculation of the air leaving the cooling tower containing small drops of water and steam, which condenses when mixed with cold outside air. In such cases, icing of the fan blades can be avoided in the following ways: reduce the cooling fan fan speed, check the pressure in front of the nozzles and, if necessary, clean them, use fiberglass blade impellers, use autonomous heating of the fan shells using flexible electric heaters. It should be noted that uneven ice formation on the blades can lead to unbalancing and vibration of the fan. If in the winter period for any reason the fans of the cooling towers were turned off, then before starting them it is necessary to check the condition of the shells for the presence of ice on them. If ice is found, it must be removed to avoid damage to the fan impellers.

Claims (2)

1. A recycled water supply system using cooling towers, comprising cooling towers interconnected by hydraulic circuits for preparing and consuming water, characterized in that each of the interconnected cooling towers contains a housing, in the lower part of which there is a tank for collecting water with a water recharge system for evaporation, which is connected to a pump supplying water cooled in the cooling tower to the consumer through the filter, and a hydraulic monitoring system is installed between the filter and the consumer disobedience filter consisting of a valve and a manometer. 2. A recycling water supply system using cooling towers, comprising cooling towers interconnected by hydraulic circuits for preparing and consuming water, characterized in that the cooling towers have separate hydraulic circuits for preparing and consuming water, contain each casing, at least at the bottom of which two tanks for collecting water, which are interconnected by a compensation pipe, providing hydraulic independence of the circuits for the preparation of working water and its consumption, while one the tank is connected to the pump, which supplies the water cooled in the tower to the consumer, which again flows through the valve through the pipeline to the second tank, from which the heated water is pumped through the filter and the valve through the pipeline to the manifold with nozzles located in the upper part of the tower, and between the filter and the valve, a filter hydraulic resistance control system is installed, consisting of a pressure gauge and a valve.

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