Outer cooling system with stored cold for direct current converter valve and operation method thereof

Abstract

The invention provides an outer cooling system with stored cold for a direct current converter valve and an operation method of the outer cooling system. The outer cooling system comprises an air cooler, a plate heat exchanger, a water chilling unit, a frequency fixed cold pump, a buffer tank, a thermocline type cold storage groove, a frequency conversion cold pump and a cooling water pump. The plate heat exchanger is divided into a hot side and a cold side. The outer cooling system with stored cold for the direct current converter valve is characterized in that at the hot side of the plate heat exchanger, a cooled device is connected with the air cooler, the plate heat exchanger and the cooling water pump in series so that a circulating loop can be formed; at the cold side of the plate heat exchanger, the thermocline type cold storage groove and the frequency conversion cold pump are connected in series so that a cold storage tank cold supply branch can be formed, the water chilling unit, the frequency fixed cold pump and the buffer tank are connected in series so that a water chilling unit cold supply branch can be formed, and the cold storage tank cold supply branch and the water chilling unit cold supply branch are connected with the plate heat exchanger in series after being connected in parallel so that a cold-side circulating cold supply loop can be formed. Compared with the prior art, the outer cooling system with stored cold for the direct current converter valve and the operation method of the outer cooling system have the advantages that the cold storage temperature difference range is wide, the high-temperature resistant capacity is achieved in summer, and the anti-freezing capacity is achieved through heat storage in winter.

Description

technical field [0001] The invention relates to an external cooling system, in particular to an external cooling system with cold storage for a DC converter valve and an operating method thereof. Background technique [0002] As my country's high-voltage direct current transmission technology becomes increasingly mature, the construction of direct current transmission projects is in a golden period of development. In the high-voltage direct current transmission system, the cooling system is an important component of the heat dissipation system of the converter valve, and its operation directly affects the power transmission capacity of the entire direct current system. Therefore, it is particularly important to ensure the stable, reliable and efficient operation of the cooling system. [0003] The closed circulating water cooling system of modern high-power power electronic devices usually uses air coolers as external cooling equipment in high cold and water-scarce areas. T...

AI Technical Summary

Problems solved by technology

Due to the periodic change of ambient temperature, when the difference between the inlet water temperature of the air cooler and the ambient temperature is small, the efficiency of the air cooler will be very low and the air cooler will occupy a very large area

Due to the large number of air coolers, the pressure ratio and space layout of pipelines often become a difficult problem for technicians; on the other hand, many converter stations reach the limit temperature and the annual cumulative time within 5°C near the limit is very short , causing the air cooler bank to be idle for much of the year

Finally, the current water-cooling systems all use devices without cold storage, the system has small heat capacity, small thermal inertia, and is highly sensitive to climate

When the temperature of the system rises too fast, the transition time from alarm to trip is very short, and false alarm signals such as tripping will be generated, which will affect the normal operation of the converter valve; design a large number of heaters

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