KR-20260062982-A - Air Source Heat Pump

KR20260062982AKR 20260062982 AKR20260062982 AKR 20260062982AKR-20260062982-A

Abstract

A method is provided to be performed by a controller of an air source heat pump, wherein the heat pump has an air heat exchanger comprising a plurality of independently controllable flow paths for transporting a refrigerant, and the method comprises the step of operating the heat pump in a heating mode used to extract energy from ambient air using the distribution of refrigerant flows through the plurality of independently controllable flow paths of the air heat exchanger; and The method includes the step of implementing an incremental defrosting procedure by adjusting the distribution of refrigerant flows in a plurality of independently controllable flow paths to selectively defrost a portion of the air heat exchanger while allowing the refrigerant to continue flowing through at least some of the independently controllable flow paths to continuously extract energy from the ambient air by operating the heat pump in a heating mode. A corresponding device is also provided.

Inventors

캐슬스, 제이슨

Assignees

옥토퍼스 에너지 히팅 리미티드

Dates

Publication Date: 20260507
Application Date: 20240827
Priority Date: 20230913

Claims (20)

An air source heat pump comprising an air heat exchanger and a controller for receiving a liquid refrigerant to extract energy from ambient air flowing over the air heat exchanger during use, The air heat exchanger has a plurality of independently controllable flow paths for transporting refrigerant through the air heat exchanger, and the air heat exchanger is part of an assembly comprising a flow control arrangement coupled to the controller and operable under the control of the controller to selectively adjust the flow of refrigerant through the plurality of independently controllable flow paths; the heat pump has a first distribution of refrigerant flows across the plurality of independently controllable flow paths to extract energy from ambient air in a heating mode; and An air source heat pump, wherein the controller is programmed to control the flow control device to implement an incremental defrosting procedure in which the distribution of refrigerant flows through a subset of the plurality of independently controllable flow paths is adjusted to selectively defrost a first portion of the air heat exchanger while the refrigerant continues to flow through at least some of the independently controllable flow paths so as to enable the heat pump to continue extracting energy from ambient air during the defrosting procedure.
In Article 1, An air source heat pump, wherein the controller is programmed to switch the distribution of refrigerant flows through some of the plurality of independently controllable flow paths to a first defrosting mode different from the distribution of the heating mode, in order to selectively defrost the first portion of the air heat exchanger before returning to the first distribution of refrigerant flows.
In Article 2, An air source heat pump, wherein the above incremental defrosting procedure comprises switching the distribution of refrigerant flows through some of the plurality of independently controllable flow paths from the first distribution of refrigerant flows to a second defrosting mode that is different from the distributions of the heating mode and the first defrosting mode, before the controller returns from the first distribution of refrigerant flows to the first distribution of refrigerant flows.
In Article 2 or Article 3, An air source heat pump, wherein the first defrosting mode comprises selectively suppressing the flow of refrigerant through only some, rather than all, of the independently controllable flow paths while maintaining flow through one or more other flow paths among the independently controllable flow paths.
In Article 4, An air heat source heat pump, wherein the second defrosting mode comprises resuming the flow of refrigerant through the independently controllable flow path(s) in which the flow is selectively suppressed in the first defrosting mode, and selectively suppressing the flow through at least some of the one or more independently controllable flow paths in which the flow is maintained in the first defrosting mode.
In Article 1, The above defrosting procedure comprises: a first step in which the flow control device is controlled to selectively suppress the flow of refrigerant through only some, but not all, of the independently controllable flow paths while maintaining flow through one or more other flow paths among the independently controllable flow paths; and a step of subsequently controlling the flow control device to resume the flow of refrigerant through the independently controllable flow path(s) in which the flow was selectively suppressed in the first step, and to selectively suppress the flow through at least some of the one or more independently controllable flow paths in which the flow was maintained in the first step, for an air heat source heat pump.
In Article 6, An air heat source heat pump, wherein the controller is configured to resume the flow of a refrigerant through the independently controllable flow path(s) through which the flow is selectively suppressed in the first stage before selectively suppressing the flow through at least some of the one or more independently controllable flow paths through which the flow is maintained in the first stage.
In Article 6, An air heat source heat pump configured such that the controller selectively suppresses flow through at least some of the one or more independently controllable flow paths in which flow is maintained in the first stage, while simultaneously resuming flow of refrigerant through the independently controllable flow path(s) in which flow is selectively suppressed in the first stage.
In Article 6, An air heat source heat pump configured such that the controller initiates the selective suppression of flow through at least some of the one or more independently controllable flow paths in which flow is maintained in the first stage, and simultaneously initiates the resumption of flow of refrigerant through the independently controllable flow path(s) in which flow is selectively suppressed in the first stage.
In any one of paragraphs 1 through 9, The air heat exchanger is an air source heat pump having at least three independently controllable flow paths to transport refrigerant through the air heat exchanger.
In any one of Articles 1 to 10, The above flow control device is an air heat source heat pump comprising a dedicated expansion valve for each of the independently controllable flow paths.
In any one of paragraphs 1 to 11, An air heat source heat pump, wherein each of the independently controllable flow paths comprises a plurality of conduits for the passage of the refrigerant.
In Article 12, For each independently controllable flow path, the conduits of the plurality of conduits are connected in parallel to a refrigerant distributor, an air heat source heat pump.
In Article 12 or Article 13, An air source heat pump, wherein, for each independently controllable flow path within the air heat exchanger, the conduits of the plurality of conduits are clustered into one or more groups of the plurality of conduits.
In Article 14, The groups of conduits for the different independently controllable flow paths are interleaved in an air heat source heat pump.
In any one of paragraphs 1 to 12, The above independently controllable flow paths are interleaved such that one or more conduits of a first independently controllable flow path within the air heat exchanger are flanked on each side by one or more conduits of different independently controllable flow paths, in an air heat source heat pump.
In any one of paragraphs 1 to 16, An air source heat pump comprising a refrigerant sub-cooler (306) arranged so as to receive little or no airflow and to allow the refrigerant to flow before reaching the flow control device (302).
In any one of paragraphs 1 through 17, The above controller (400) is configured to determine the need to perform an air heat exchanger defrosting event based at least partially on a change in the power consumption characteristics of the fan motor (404) of the heat pump, an air heat source heat pump.
In Article 18, The above power consumption characteristic is an air heat source heat pump, which is the amount of current consumed or the rate of change in current consumption.
In any one of paragraphs 1 through 19, The above controller (400) is configured to control the flow control device to selectively suppress the flow of the refrigerant by stopping the flow of the refrigerant through the selected independently controllable flow paths while maintaining the flow through one or more other flow paths among the independently controllable flow paths, in an air heat source heat pump.

Description

Air Source Heat Pump The present invention relates to an air source heat pump and an air heat exchanger for an air source heat pump. According to Directive 2012/27/EU, buildings account for 40% of final energy consumption and 36% of CO2 emissions. The EU Commission’s 2016 report, "Mapping and Analysis of Heating/Cooling Fuel Deployment (Fossil/Renewable Energy) Now and in the Future (2020-2030)," concluded that heating and hot water alone account for 79% (192.5 Mtoe) of total final energy use in EU households. The EU Commission also reported, based on 2019 Eurostat figures, that approximately 75% of heating and cooling is still generated from fossil fuels, while only 22% is generated from renewable energy. To achieve the EU’s climate and energy goals, the heating and cooling sector must drastically reduce energy consumption and decrease the use of fossil fuels. Heat pumps, which utilize energy drawn from air, land, or water, have been identified as potentially significant contributors to addressing this issue. Since only a fraction of households have access to a body of water to support the use of heat pumps that extract energy from water, and the cost and space requirements for installing ground source heat exchangers are also substantial, it is generally cheaper and more convenient to install air source heat pumps. Furthermore, it is generally recognized that air source heat pumps are a better replacement for conventional central gas heating boilers. However, air source heat pumps have one disadvantage not shared by heat pumps that extract energy from bodies of water or the ground: when the heat pump is operated to extract energy from ambient air ("heating mode"), the air heat exchanger of the heating pump must be periodically defrosted in mild and cooler climates. An air heat exchanger is a heat exchanger in which heat from ambient air is transferred to a liquid refrigerant in heating mode. Typically, a matrix of finned tubes (more commonly conduits) contains the cold liquid refrigerant, and ambient air is moved over the tubes by the action of a fan or impeller. In heating mode, energy is extracted from the ambient air because the liquid refrigerant is colder than the ambient air; as the temperature rises, the liquid refrigerant vaporizes and the temperature of the ambient air decreases. Consequently, water vapor carried by the ambient air tends to condense on the surface of the air heat exchanger. If the ambient air temperature is sufficiently low, water condensing on the surface of the air heat exchanger will freeze to form ice. The accumulation of ice reduces the heat transfer efficiency of the air heat exchanger, and significant ice accumulation can block the gaps between adjacent conduits of the air heat exchanger, causing a loss of airflow and thus a further reduction in efficiency. Consequently, air source heat pumps are sometimes configured to perform what is known as a defrosting cycle while warm refrigerant is fed into the air heat exchanger to melt the ice and thus restore the efficiency of the air heat exchanger. Generally, a defrosting cycle involves the bypass of hot gas from the compressor discharge or high-pressure receiver to the air heat exchanger (known as hot gas defrosting) or the reversal of the usual energy extraction cycle (essentially running the heat pump in cooling mode for a short time) so that the heat pump operates in reverse to transfer energy from the home to the ambient air. The frequency of defrosting cycle events is every 35 minutes, perhaps for 10 minutes at a time, but depends on ambient conditions and, among other things, the amount of heat load the system intends to deliver. Understandably, the overall efficiency of the air source heat pump is reduced by the need to drive the heat pump in reverse to defrost the air heat exchanger. The present invention seeks to provide an air source heat pump in which at least some of the disadvantages of existing air source heat pumps are wholly or partially mitigated. According to one embodiment, an air source heat pump is provided, comprising an air heat exchanger and a controller for receiving a liquid refrigerant to extract energy from ambient air flowing over the air heat exchanger when in use, wherein the air heat exchanger has a plurality of independently controllable flow paths for transporting the refrigerant through the air heat exchanger, and the air heat exchanger is part of an assembly comprising a flow control arrangement coupled to the controller and operable under the control of the controller to selectively adjust the flow of the refrigerant through one or more of the plurality of independently controllable flow paths; The controller is programmed to implement an incremental defrosting procedure comprising controlling a flow control device to perform a first change in the rate of refrigerant flow through one or more of a plurality of independently controllable flow paths to selectively defrost parts of the heat exc