Self-regulating steady-state low-temperature heat-pump water heater and operating method thereof

Abstract

The invention relates to a self-regulating steady-state low-temperature heat-pump water heater comprising an evaporator, a condenser, a compressor, a control device, a four-way reversion valve, a medium-pressure receiver and an intermediate heat exchanger which can form a closed main loop, wherein the four-way reversion valve is positioned on a connection access arranged between the evaporator and the condenser, the medium-pressure receiver and the intermediate heat exchanger are arranged on the other connection access arranged between the evaporator and the condenser, and a temperature sensor, an electronic expansion valve and a pressure sensor are positioned on the closed main loop. The self-regulating steady-state low-temperature heat-pump water heater is characterized in that an air-supply loop is arranged between the compressor and the intermediate heat exchanger. The self-regulating steady-state low-temperature heat-pump water heater has a main purpose of preventing hot-water preparation capacity reduction at low environmental temperature and a secondary purpose of ensuring the stable state of a refrigerant when heat load changes in the condenser and realizing higher heat-exchange performance in the condenser.

Description

technical field [0001] The invention relates to a heat pump water heater, in particular, the invention relates to a steady-state flow self-regulating low-temperature heat pump water heater and an application method thereof. Background technique [0002] Heat pump water heater is an emerging hot water production equipment in recent years. It is powered by electricity, easy to install, short construction period, small footprint, no need for fuel storage, no transportation costs for slag discharge and three waste treatment expenses, and no special duty. For the centralized hot water supply system in urban dense areas, the compression heat pump water heater unit shows obvious advantages. [0003] On the other hand, the heat pump can provide heat throughout the year and cool in summer by absorbing natural energy from the environment, waste heat, and waste heat. It is an efficient, energy-saving and pollution-free technology that utilizes renewable energy. The heating power of th...

AI Technical Summary

Problems solved by technology

[0005] When the air source heat pump water heater operates at a low ambient temperature (such as -10°C), the system operates at a low evaporation temperature, the suction specific gravity is small, the circulation flow rate is small, and the superheat of the suction air cannot be guaranteed, which makes the heating efficiency low. As the water temperature rises gradually, the exhaust temperature rises

Especially at high water temperature (such as 60°C), the compression ratio of the system is too large. If the compressor runs for a long time under the condition of such a large compression ratio, the lubricating oil will become thinner or even carbonized and coked, which will eventually cause the compressor to burn

At the same time, when the traditional heat pump water heater is heating, the state of the refrigerant in the condenser changes with the change of the heating load, resulting in the problem of unstable heat exchange performance

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