Analysis of the power consumption of the two types of industrial chillers, air-cooled chillers and water-cooled chillers, commonly used in refrigeration. What are their characteristics? They also have shortcomings. How should we solve these problems? Today we will carefully analyze the power consumption of these two types of chillers.
Air-cooled chillers are expensive, bulky, and noisy. These are facts. However, the comparative power consumption of literature is by no means comprehensive. Based on the cooling capacity of 3520KW (1000USrt), air-cooled chillers and chillers consume more power. As a result, the air-cooled unit system is 350KW than the water-cooled unit system. If the whole summer, greater power.
Air-cooled units are expensive and noisy. If the operating cost is indeed much higher than that of water-cooled units, then (according to the original ratio of about 28%), then it will not be able to win the market, and it cannot explain the tens of thousands of large-scale units so far. The fact that air-cooled chillers operate.
Two issues should be clear: a unit with installed capacity is not equal to energy consumption; second, the efficiency and energy consumption of units operating under full load and partial load are different.
At full load, the air-conditioning cold water is higher than the temperature of the water-cooled condensing unit, and the air-cooled chiller is a power machine where the pressure is greater, but the distribution of the air-conditioning load throughout the summer is extremely unbalanced, even in its one hour, the daily load is also very different According to the maximum load of the unit, the operating time is very limited. According to general statistics, the time when the air conditioning load is above 90% is only 7% to 8% full-time, and 60% will account for 60% of the 50% load. This means that the chiller is not almost at full load in summer. Therefore, it is obviously inappropriate to use installed capacity equipment (or input power at full load) as the relatively basic power consumption throughout the year.
The condensation temperature of air-cooled chillers depends on the outdoor dry bulb temperature, and the condensation temperature of water-cooled chillers depends on the outdoor wet bulb temperature. In a single day, the outdoor air dry bulb temperature is much greater than the wet bulb temperature. In the southern part of China, the daytime temperature in summer is generally 8-10 ℃ per day, and in more arid areas, even as high as 15-16 ℃, the change in wet bulb temperature within a day is very small (the dry bulb temperature is only 1/5 Around). In this way, the temperature of the water-cooled condensing unit is almost unchanged in a day, while the outdoor dry bulb temperature of the air-cooled unit will drop. The conclusion that the air-cooled unit must be better than the water-cooled type with high condensing temperature by 5? 10 ℃, and that the resulting air-cooled unit must be greater than the water-cooled unit is obviously incorrect.
The United States has adopted the energy consumption comparison of Trane centrifugal water-cooled chillers and air-cooled centrifugal chillers at full load and partial load. The energy consumption of the unit is about 15% larger than that of the water-cooled chiller, but on February 3, the load between the two countries is basically the same, and the air-cooled unit is slightly lower, while at 1/3 load, the air-cooled unit is far It is about 30% lower than that of water-cooled units. Therefore, in general, air-cooled chillers and annual energy consumption are not less than a large number of water-cooled units, together with equipment maintenance costs for water cooling devices (maintenance of cooling tower systems, water treatment, condensation It is higher than that of air-cooled units, so that the total operating cost of air-cooled units may also be slightly lower than that of water-cooled units.
