Multifunctional heat pump system

Abstract

The invention discloses a multifunctional heat pump system, and aims to provide a heat pump system which is suitable for a small heat pump system and can be implemented by splicing a plurality of heatpump modules. The multifunctional heat pump system comprises a first heat pump unit and a second heat pump unit, wherein each of the first heat pump unit and the second heat pump unit comprise a plurality of heat pump modules of the same structure; and each heat pump module comprises a refrigeration compressor, an outdoor heat exchanger, an indoor heat exchanger, a four-way reversing valve, an expansion valve, a one-way valve, a first valve, a second valve, a third valve, a fourth valve and a fifth valve. The multifunctional heat pump system can realize hot-gas bypass circulation in various forms during the summer cooling and winter heating, can realize the effect of defrosting the indoor heat exchanger by means of hot-gas bypass in winter heating, and has simple structure and high energyefficiency ratio.

Description

technical field [0001] The invention relates to the technical field of heat pumps, and more specifically, relates to a multifunctional heat pump system that is flexibly spliced ​​with multiple heat pump modules. Background technique [0002] With the adjustment of energy structure and the proposal of global sustainable development strategy, people pay more and more attention to the development and utilization of clean, safe and efficient energy. The air source heat pump system uses electric energy as the driving force, and uses outdoor ambient air as a heat source and heat sink to provide cooling and heat to the regulated object. It is one of the environmentally friendly and efficient energy supply methods that the country is promoting. [0003] At present, due to commercial reasons, there are more and more studies on large-scale units, and less research on small-scale heat pump systems. Judging from the actual operation effect of the current small air source heat pumps, th...

AI Technical Summary

Problems solved by technology

Judging from the actual operation effect of the current small air source heat pumps, the unit is still not ideal for heating. When the cooling load is low or the outdoor ambient temperature is low, the suction pressure of the compressor is low, and the flow rate of the circulating refrigerant is small, which will cause insufficient oil return of the compressor lubricating oil, resulting in deterioration of the lubrication conditions and wear of the compressor cylinder

Moreover, long-term operation of the system below the designed suction pressure will cause the compressor motor to overheat, resulting in damage to the compressor motor coil

In order to protect the compressor, a low-pressure shutdown fault is usually added to the control system, that is, the compressor will stop immediately when the suction pressure is too low, and the compressor will not be allowed to start until the suction pressure rises to a safe value. The compressor starts frequently, which shortens the life of the compressor

Secondly, the most common defrosting method for air source heat pump units is reverse cycle defrosting. This defrosting method has many disadvantages. For example, it needs to absorb heat from the room during defrosting, and the room temperature will drop by 5-6°C, which will affect the comfort of the room. ;When switching between heating and defrosting modes, the system pressure fluctuates violently, resulting in a relatively large mechanical impact; when defrosting, the indoor heat exchanger is used as an indoor heat exchanger, and the surface temperature is as low as -20~-25°C. After that, no hot air can be blown out for a long period of time; when the defrosting is started and terminated, the four-way valve reversing produces a large airflow noise, and this defrosting method will reduce the indoor temperature during defrosting, and the noise is relatively large

Thirdly, considering the cost, the capacity of the indoor and outdoor heat exchangers of the existing small heat pump units is fixed, and the working conditions of the heat pump units are unstable all the year round. When the unit is supplying cooling and heat, the capacity of the indoor and outdoor heat exchangers cannot Condition change regulation

In addition, for the application of heat pump units in multiple rooms such as homes and hotels, a small heat pump unit is mostly used in each room. Each heat pump unit is completely independent and has no connection. However, the cooling or heating requirements of each room are different. , when the small heat pump unit is not working, the waste of equipment is formed, and all the devices in the small heat pump system are single, and the damage of one device will lead to the paralysis of the entire heat pump system. Considering the cost saving, generally do not design spare devices, Affect the normal operation of the entire system

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