Control method and device for screw water chiller and air conditioner

Abstract

The invention discloses a control method and device for a screw water chiller and an air conditioner. The method includes the steps that after the screw water chiller enters an operating state, the air suction saturation pressure Pe, exhaust saturation pressure Pp, exhaust temperature Tp, evaporation temperature Te, condensation temperature Tc and load Q of a compressor in the screw water chiller are detected in real time; the difference value between the exhaust saturation pressure Pp and the air suction saturation pressure Pe is acquired; and the opening degree of an electronic expansion valve in the screw water chiller is controlled according to the pressure difference value and the air suction saturation pressure Pe. According to the method, on the premise of meeting the high chilled water outlet temperature energy saving requirement of a customer, by monitoring the air suction saturation pressure and exhaust saturation pressure of the water chiller at every moment, it is guaranteed that the evaporation temperature does not exceed the affirmatory evaporation temperature upper limit of the compressor, and it is also guaranteed that the high and low pressure difference meets the requirement for the minimum oil supply pressure difference, so that reliable operating of the water chiller is guaranteed, and energy saving of the water chiller is also guaranteed.

Description

technical field [0001] The invention relates to the technical field of chillers, in particular to a control method and a control device for a screw chiller and an air conditioner with the control device. Background technique [0002] As energy-saving products are increasingly favored by users, users no longer blindly require chilled water to reach a lower temperature (such as 7°C), but to optimize the design of the air-conditioning system according to the climate characteristics of the location, that is, according to the actual situation of the specific project Therefore, in projects such as clean rooms, airports, or in low-humidity air areas in Northwest China, the chilled water outlet temperature range required by users should be raised from the conventional lower temperature (such as 7°C) to High temperature (such as 12 ~ 20 ℃). [0003] For the conventional semi-hermetic compressor system, the compressor mostly adopts pressure differential oil supply. When the high and ...

AI Technical Summary

Problems solved by technology

However, due to the addition of the pressure maintenance valve, the structure of the chiller will be more complicated than that of the conventional system. At the same time, since the pressure maintenance valve is installed on the exhaust pipeline, the loss of the compressor in the exhaust pipeline will be increased, and the energy efficiency of the unit will be reduced. Even, in When the pressure maintenance method is not fully opened, there will be air flow sound, affecting comfort

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