Hydraulic filling type screw water-cooled cold water and heat pump unit

Abstract

The invention provides a hydraulic filling type screw water-cooled cold water and heat pump unit and relates to the technical field of air conditioning refrigeration. The hydraulic filling type screw water-cooled cold water and heat pump unit comprises a refrigerating system which is composed of a compressor, a condenser, a dry filter, a liquid viewed glass, an expansion valve and an evaporator in sequent connection. The hydraulic filling type screw water-cooled cold water and heat pump unit is characterized in that the compressor is the oil-content-carrying semi-closed type screw compressor, and a pressure maintaining valve is arranged between the compressor and the condenser. An inlet of the pressure maintaining valve is connected with an exhaust opening of the compressor, an air inlet of the condenser is connected with an outlet of the pressure maintaining valve, and a balance opening of the pressure maintaining valve is connected with a low pressure side of the compressor through a balance pipe. Compared with the prior art, the hydraulic filling type screw water-cooled cold water and heat pump unit has the advantages of being capable of enabling differential pressure needed by system operation to be quickly established, lubricating the unit, and ensuring normal start and safe and reliable operation of the system.

Description

technical field [0001] The invention relates to the technical field of air conditioning and refrigeration, in particular to a flooded screw water-cooled chiller / heat pump unit. Background technique [0002] In the prior art, flooded units using large-capacity screw compressors are favored by users due to their large cooling capacity and high cooling performance coefficient. However, because most of the large screw refrigeration compressors of this product are external oil circulation systems, the oil supply scheme generally adopts two methods: one is to supply oil with the oil pump as the power, but the oil seal of the oil pump has a short working life , Unscheduled replacement will cause system refrigerant and oil leakage loss, so the oil pump is not suitable for long-term operation, and the maintenance and replacement of the oil seal of the oil pump is very troublesome. The other is to use the pressure difference between the suction and discharge of the compressor as the...

AI Technical Summary

Problems solved by technology

However, because most of the large screw refrigeration compressors of this product are external oil circulation systems, the oil supply scheme generally adopts two methods: one is to supply oil with the oil pump as the power, but the oil seal of the oil pump has a short working life , Failure to replace it on schedule will cause leakage loss of system refrigerant and oil, so the oil pump is not suitable for long-term operation, and the maintenance and replacement of the oil seal of the oil pump is very troublesome

The other is to use the pressure difference between the suction and discharge of the compressor as the power to supply oil. However, during the start-up stage of the unit, since the temperature of the refrigerant water and the cooling water have not been separated, the normal oil supply system of the compressor cannot be established in a short time. Due to the working pressure difference, the compressor cannot complete the loading process, and the low oil supply can also lead to lubrication failure and damage the compressor

The usual method is to adjust the valve of the water system to reduce the amount of refrigerant water or cooling water, and then gradually return to the normal water amount of the unit after a certain pressure difference is established in the system. This method is labor-intensive and requires professional guidance. If the waterway adopts automatic control, then The cost is high, and the operating reliability of the unit is poor

As a result, the wide application of such products in the domestic market is restricted, and this technical problem has not been well resolved.

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