Variable frequency heat pump unit and control method thereof

Abstract

The invention discloses a variable frequency heat pump unit and a control method thereof. The variable frequency heat pump unit comprises one or more variable frequency compressors connected in parallel, an oil separator, a reversing valve, a condenser, a throttling mechanism, an evaporator, a gas-liquid separator and a variable frequency fan, a normal oil return path and a forced oil return path which are connected in parallel are arranged between the oil separator and air return ports of the compressors, and a system pressure balancing pipeline is arranged between the high-pressure side and the low-pressure side of the unit. The variable frequency heat pump unit is high in refrigerating and heating capacity, good in energy-saving effect, short in response time, flexible in application and good in user experience; according to the control method for the compressors connected in parallel in the variable frequency heat pump unit, safe, efficient, stable and energy-saving operation of the variable frequency heat pump unit is ensured through the steps of starting, stopping, adding and switching, and control is flexible and convenient; and the variable frequency heat pump unit is particularly suitable for being used by vast industrial and commercial users.

Description

technical field [0001] The invention relates to the technical field of heat pump units, in particular to a frequency conversion heat pump unit and a control method thereof. Background technique [0002] A heat pump is a mechanical device that uses artificial technology to convert low-temperature heat energy into high-temperature heat energy to achieve cooling / heating effects. When the heat pump is running, it absorbs heat energy from a low-temperature heat source, and then converts it into a higher-temperature heat source and releases it to the required space. It can be used as a heating and heating device, and can also be used as a cooling and cooling device to achieve the purpose of one machine with two uses. Since the heat pump has the advantages of green environmental protection, energy saving and high efficiency, which is in line with the current basic policy of energy and environmental protection in my country, the application of heat pump units is becoming more and mo...

AI Technical Summary

Problems solved by technology

[0003] The compressor is the core component of the entire heat pump unit. Most of the compressors in the current heat pump unit still use the fixed frequency mode. The fixed frequency compressor has at least the following disadvantages: once the set temperature is reached, it will automatically stop; if the temperature reaches If the temperature is lower than the set temperature, it will automatically start up; when encountering power failures such as voltage instability, the compressor will stop rotating; such frequent shutdowns and restarts will consume a lot of power and greatly reduce the service life of the compressor , which greatly reduces the flexibility of use of the heat pump unit

[0004] At present, although frequency conversion heat pump units have also appeared, there is still a lot of room for improvement in terms of safety, efficient operation, and flexible control of existing frequency conversion heat pump units, which urgently need to be solved by those skilled in the art

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