CN114992889A - Cascade heat pump system and control method thereof - Google Patents

Cascade heat pump system and control method thereof Download PDF

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CN114992889A
CN114992889A CN202210579892.XA CN202210579892A CN114992889A CN 114992889 A CN114992889 A CN 114992889A CN 202210579892 A CN202210579892 A CN 202210579892A CN 114992889 A CN114992889 A CN 114992889A
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pressure refrigerant
low
refrigerant circulation
bypass branch
heat exchanger
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CN114992889B (en
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周明杰
何建奇
李银银
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Qingdao Haier Air Conditioner Gen Corp Ltd
Qingdao Haier Air Conditioning Electric Co Ltd
Haier Smart Home Co Ltd
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Qingdao Haier Air Conditioner Gen Corp Ltd
Qingdao Haier Air Conditioning Electric Co Ltd
Haier Smart Home Co Ltd
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B7/00Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00Fluid-circulation arrangements
    • F25B41/20Disposition of valves, e.g. of on-off valves or flow control valves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B41/00Fluid-circulation arrangements
    • F25B41/40Fluid line arrangements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00Arrangement or mounting of control or safety devices
    • F25B49/02Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B30/00Energy efficient heating, ventilation or air conditioning [HVAC]
    • Y02B30/70Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

The invention relates to the technical field of cascade heat pumps, in particular to a cascade heat pump system and a control method thereof, and aims to solve the problem that the existing cascade heat pump system is easily influenced by the ambient temperature and has a narrow operation range. Therefore, the cascade heat pump system comprises a high-pressure refrigerant circulation loop, a first low-pressure refrigerant circulation loop, a second low-pressure refrigerant circulation loop and a bypass branch, wherein the first low-pressure refrigerant circulation loop, the second low-pressure refrigerant circulation loop and the bypass branch can selectively run; based on the above, the cascade heat pump system of the invention controls the operation states of the first low-pressure refrigerant circulation loop and the second low-pressure refrigerant circulation loop according to the acquired environment temperature, so as to effectively reduce the operation energy consumption of the cascade heat pump system; the running state of the bypass branch is controlled according to the obtained running parameters of the high-pressure refrigerant circulating loop, so that the high-pressure refrigerant circulating loop can be effectively ensured to run all the time by controlling the on-off state of the bypass branch, and the running range of the cascade heat pump system is effectively expanded.

Description

复叠式热泵系统及其控制方法Cascade heat pump system and control method thereof

技术领域technical field

本发明涉及复叠式热泵技术领域,具体提供一种复叠式热泵系统及其控制方法。The invention relates to the technical field of cascade heat pumps, and in particular provides a cascade heat pump system and a control method thereof.

背景技术Background technique

随着节能减排的政策推广,食品加工、纺织和化工等行业使用高温热泵系统进行高温加热处理的应用场合越来越多。工业加热需求旺盛,对高温热泵系统的应用要求也越来越高。首先,高温热泵系统的最终供热温度一般大于70℃甚至超过90℃。其次,供热系统的应用环境温度从-30℃到35℃,甚至跨度更大,无论冬季还是夏季都需要提供高温热水或热风。With the promotion of energy saving and emission reduction policies, there are more and more applications where high temperature heat pump systems are used for high temperature heating in food processing, textile and chemical industries. The demand for industrial heating is strong, and the application requirements for high-temperature heat pump systems are also getting higher and higher. First of all, the final heating temperature of the high temperature heat pump system is generally greater than 70°C or even more than 90°C. Secondly, the application environment temperature of the heating system ranges from -30°C to 35°C, or even a larger span. High-temperature hot water or hot air needs to be provided in winter or summer.

工业使用的高温热水温度较高,这就导致普通热泵系统无法达到实际的加热使用需求,将复叠式热泵系统用来提供高温热水的技术已经非常成熟。复叠式热泵系统一般包括高压冷媒循环回路和低压冷媒循环回路,高压冷媒循环回路和低压冷媒循环回路通过共用的中间换热器进行换热,以达到提供高温热水的目的。然而,现有的复叠式热泵系统受环境温度的限制,在环境温度更高或更低时无法运行,即,现有的复叠式热泵系统的运行范围较窄,无法始终为用户提供热水,给用户带来不便。The high temperature of the high-temperature hot water used in industry is high, which makes the ordinary heat pump system unable to meet the actual heating demand. The technology of using the cascade heat pump system to provide high-temperature hot water is very mature. Cascade heat pump system generally includes high-pressure refrigerant circulation loop and low-pressure refrigerant circulation loop. However, the existing cascade heat pump system is limited by the ambient temperature and cannot operate when the ambient temperature is higher or lower, that is, the existing cascade heat pump system has a narrow operating range and cannot always provide heat to users water, causing inconvenience to users.

相应地,本领域需要一种新的复叠式热泵系统及其控制方法来解决上述技术问题。Accordingly, there is a need in the art for a new cascade heat pump system and a control method thereof to solve the above technical problems.

发明内容SUMMARY OF THE INVENTION

本发明旨在解决上述技术问题,即,解决现有复叠式热泵系统容易受环境温度的影响而运行范围较窄的问题。The present invention aims to solve the above-mentioned technical problem, that is, to solve the problem that the existing cascade heat pump system is easily affected by the ambient temperature and has a narrow operating range.

在第一方面,本发明提供一种复叠式热泵系统的控制方法,所述复叠式热泵系统包括高压冷媒循环回路、第一低压冷媒循环回路、第二低压冷媒循环回路和旁通支路,In a first aspect, the present invention provides a control method for a cascade heat pump system, the cascade heat pump system includes a high pressure refrigerant circulation loop, a first low pressure refrigerant circulation loop, a second low pressure refrigerant circulation loop and a bypass branch ,

所述高压冷媒循环回路上设置有第一压缩机、第一换热器、第一节流构件和中间换热器,所述第一低压冷媒循环回路上设置有第二压缩机、所述中间换热器、第二节流构件和第二换热器,所述第二低压冷媒循环回路上设置有氟泵、所述第二换热器和所述中间换热器,所述氟泵的两端与所述第一低压冷媒循环回路相连,所述第二压缩机的两端与所述第二低压冷媒循环回路相连,所述第一低压冷媒循环回路和所述第二低压冷媒循环回路设置成能够选择性地通过所述中间换热器与所述高压冷媒循环回路进行换热,A first compressor, a first heat exchanger, a first throttling member and an intermediate heat exchanger are arranged on the high-pressure refrigerant circulation circuit, and a second compressor, the intermediate heat exchanger are arranged on the first low-pressure refrigerant circulation circuit A heat exchanger, a second throttling member and a second heat exchanger, the second low-pressure refrigerant circulation loop is provided with a fluorine pump, the second heat exchanger and the intermediate heat exchanger, the fluorine pump is Both ends are connected to the first low-pressure refrigerant circulation circuit, both ends of the second compressor are connected to the second low-pressure refrigerant circulation circuit, the first low-pressure refrigerant circulation circuit and the second low-pressure refrigerant circulation circuit is arranged to be able to selectively exchange heat with the high-pressure refrigerant circulation loop through the intermediate heat exchanger,

所述旁通支路的第一端连接至所述氟泵与所述第一低压冷媒循环回路的连接点和所述第二换热器之间,所述旁通支路的第二端连接至所述第二压缩机和所述中间换热器之间,所述旁通支路上设置有控制阀,所述控制阀设置成能够控制所述旁通支路的通断状态,The first end of the bypass branch is connected between the connection point between the fluorine pump and the first low-pressure refrigerant circulation loop and the second heat exchanger, and the second end of the bypass branch is connected Between the second compressor and the intermediate heat exchanger, a control valve is arranged on the bypass branch, and the control valve is arranged to be able to control the on-off state of the bypass branch,

所述控制方法包括:The control method includes:

获取所述复叠式热泵系统所处的环境温度;obtaining the ambient temperature where the cascade heat pump system is located;

根据所述环境温度,控制所述第一低压冷媒循环回路和所述第二低压冷媒循环回路的运行状态;controlling the operating states of the first low-pressure refrigerant circulation loop and the second low-pressure refrigerant circulation loop according to the ambient temperature;

获取所述高压冷媒循环回路的运行参数;Obtain the operating parameters of the high-pressure refrigerant circulation loop;

根据所述高压冷媒循环回路的运行参数,控制所述旁通支路的运行状态。The operating state of the bypass branch is controlled according to the operating parameters of the high-pressure refrigerant circulation loop.

在上述控制方法的优选技术方案中,“根据所述环境温度,控制所述第一低压冷媒循环回路和所述第二低压冷媒循环回路的运行状态”的步骤包括:In a preferred technical solution of the above control method, the step of "controlling the operating states of the first low-pressure refrigerant circulation loop and the second low-pressure refrigerant circulation loop according to the ambient temperature" includes:

如果所述环境温度大于或等于预设环境温度,则控制所述第一低压冷媒循环回路不运行,且控制所述第二低压冷媒循环回路运行。If the ambient temperature is greater than or equal to a preset ambient temperature, the first low-pressure refrigerant circulation circuit is controlled to not operate, and the second low-pressure refrigerant circulation circuit is controlled to operate.

在上述控制方法的优选技术方案中,“根据所述环境温度,控制所述第一低压冷媒循环回路和所述第二低压冷媒循环回路的运行状态”的步骤还包括:In the preferred technical solution of the above control method, the step of "controlling the operating states of the first low-pressure refrigerant circulation loop and the second low-pressure refrigerant circulation loop according to the ambient temperature" further includes:

如果所述环境温度小于所述预设环境温度,则控制所述第一低压冷媒循环回路运行,且控制所述第二低压冷媒循环回路不运行。If the ambient temperature is lower than the preset ambient temperature, the first low-pressure refrigerant circulation circuit is controlled to operate, and the second low-pressure refrigerant circulation circuit is controlled to not operate.

在上述控制方法的优选技术方案中,“获取所述高压冷媒循环回路的运行参数”的步骤具体包括:In the preferred technical solution of the above control method, the step of "obtaining the operating parameters of the high-pressure refrigerant circulation loop" specifically includes:

获取所述中间换热器的当前冷媒蒸发温度和最大冷媒蒸发温度;obtaining the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature of the intermediate heat exchanger;

“根据所述高压冷媒循环回路的运行参数,控制所述旁通支路的运行状态”的步骤具体包括:The step of "controlling the operating state of the bypass branch according to the operating parameters of the high-pressure refrigerant circulation loop" specifically includes:

根据所述当前冷媒蒸发温度和所述最大冷媒蒸发温度,控制所述旁通支路的运行状态。The operating state of the bypass branch is controlled according to the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature.

在上述控制方法的优选技术方案中,“根据所述当前冷媒蒸发温度和所述最大冷媒蒸发温度,控制所述旁通支路的运行状态”的步骤具体包括:In the preferred technical solution of the above control method, the step of "controlling the operating state of the bypass branch according to the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature" specifically includes:

计算所述最大冷媒蒸发温度和所述当前冷媒蒸发温度的差值,记为第一差值;Calculate the difference between the maximum refrigerant evaporation temperature and the current refrigerant evaporation temperature, and record it as the first difference;

如果所述第一差值小于第一预设差值,则控制所述旁通支路运行;并且/或者,If the first difference is less than the first preset difference, controlling the bypass branch to operate; and/or,

如果所述第一差值大于或等于所述第一预设差值,则控制所述旁通支路不运行。If the first difference is greater than or equal to the first preset difference, the bypass branch is controlled to not operate.

在上述控制方法的优选技术方案中,“获取所述高压冷媒循环回路的运行参数”的步骤具体包括:In the preferred technical solution of the above control method, the step of "obtaining the operating parameters of the high-pressure refrigerant circulation loop" specifically includes:

获取所述第一压缩机的当前吸气压力和最大吸气压力;obtaining the current suction pressure and the maximum suction pressure of the first compressor;

“根据所述高压冷媒循环回路的运行参数,控制所述旁通支路的运行状态”的步骤具体包括:The step of "controlling the operating state of the bypass branch according to the operating parameters of the high-pressure refrigerant circulation loop" specifically includes:

根据所述当前吸气压力和所述最大吸气压力,控制所述旁通支路的运行状态。The operating state of the bypass branch is controlled according to the current suction pressure and the maximum suction pressure.

在上述控制方法的优选技术方案中,“根据所述当前吸气压力和所述最大吸气压力,控制所述旁通支路的运行状态”的步骤具体包括:In the preferred technical solution of the above control method, the step of "controlling the operating state of the bypass branch according to the current suction pressure and the maximum suction pressure" specifically includes:

计算所述最大吸气压力和所述当前吸气压力的差值,记为第二差值;Calculate the difference between the maximum inspiratory pressure and the current inspiratory pressure, denoted as the second difference;

如果所述第二差值小于第二预设差值,则控制所述旁通支路运行;并且/或者,If the second difference is less than a second preset difference, controlling the bypass branch to operate; and/or,

如果所述第二差值大于或等于所述第二预设差值,则控制所述旁通支路不运行。If the second difference is greater than or equal to the second preset difference, the bypass branch is controlled to not operate.

在上述控制方法的优选技术方案中,在所述第一低压冷媒循环回路运行且所述旁通支路不运行的情形下,所述控制方法还包括:In a preferred technical solution of the above control method, when the first low-pressure refrigerant circulation loop is running and the bypass branch is not running, the control method further includes:

获取所述第二换热器出口处的冷媒温度;obtaining the refrigerant temperature at the outlet of the second heat exchanger;

根据所述第二换热器出口处的冷媒温度,进一步控制所述旁通支路的运行状态。The operating state of the bypass branch is further controlled according to the temperature of the refrigerant at the outlet of the second heat exchanger.

在上述控制方法的优选技术方案中,“根据所述第二换热器出口处的冷媒温度,进一步控制所述旁通支路的运行状态”的步骤具体包括:In the preferred technical solution of the above control method, the step of "further controlling the operating state of the bypass branch according to the temperature of the refrigerant at the outlet of the second heat exchanger" specifically includes:

如果所述第二换热器出口处的冷媒温度小于或等于预设冷媒温度,则控制所述旁通支路运行;并且/或者,If the temperature of the refrigerant at the outlet of the second heat exchanger is less than or equal to the preset refrigerant temperature, the bypass branch is controlled to operate; and/or,

如果所述第二换热器出口处的冷媒温度大于所述预设冷媒温度,则控制所述旁通支路不运行。If the refrigerant temperature at the outlet of the second heat exchanger is greater than the preset refrigerant temperature, the bypass branch is controlled to not operate.

在另一方面,本发明还提供了一种复叠式热泵系统,所述复叠式热泵系统包括控制器,所述控制器能够执行上述任一项优选技术方案中所述的控制方法。In another aspect, the present invention also provides a cascade heat pump system, the cascade heat pump system includes a controller capable of executing the control method described in any one of the above preferred technical solutions.

在采用上述技术方案的情况下,本发明的复叠式热泵系统能够根据获取的环境温度控制第一低压冷媒循环回路和第二低压冷媒循环回路的运行状态,以有效降低复叠式热泵系统的运行能耗;还能够根据获取的高压冷媒循环回路的运行参数控制旁通支路的运行状态,进而通过控制旁通支路的通断状态有效保证高压冷媒循环回路能够始终运行,有效扩大复叠式热泵系统的运行范围,满足用户的使用需求。In the case of adopting the above technical solutions, the cascade heat pump system of the present invention can control the operating states of the first low-pressure refrigerant circulation loop and the second low-pressure refrigerant circulation loop according to the obtained ambient temperature, so as to effectively reduce the cost of the cascade heat pump system. Operating energy consumption; it can also control the operating state of the bypass branch according to the obtained operating parameters of the high-pressure refrigerant circulation loop, and then effectively ensure that the high-pressure refrigerant circulation loop can always run by controlling the on-off state of the bypass branch, effectively expanding the cascade The operating range of the heat pump system can meet the needs of users.

附图说明Description of drawings

下面结合附图来描述本发明的优选实施方式,附图中:Preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

图1是本发明的复叠式热泵系统的整体结构示意图;Fig. 1 is the overall structure schematic diagram of the cascade heat pump system of the present invention;

图2是本发明的控制方法的主要步骤流程图;Fig. 2 is the main step flow chart of the control method of the present invention;

图3是本发明的控制方法的第一优选实施例的具体步骤流程图;3 is a flow chart of the specific steps of the first preferred embodiment of the control method of the present invention;

图4是本发明的控制方法的第二优选实施例的具体步骤流程图;4 is a flow chart of the specific steps of the second preferred embodiment of the control method of the present invention;

附图标记:Reference number:

1、高压冷媒循环回路;11、第一压缩机;12、第一换热器;13、第一节流构件;14、中间换热器;1. High pressure refrigerant circulation loop; 11. First compressor; 12. First heat exchanger; 13. First throttle member; 14. Intermediate heat exchanger;

2、第一低压冷媒循环回路;21、第二压缩机;22、第二节流构件;23、第二换热器;24、第一单向阀;25、第二单向阀;2. The first low-pressure refrigerant circulation circuit; 21, the second compressor; 22, the second throttle member; 23, the second heat exchanger; 24, the first one-way valve; 25, the second one-way valve;

3、第二低压冷媒循环回路;31、氟泵;32、第三单向阀;3. The second low-pressure refrigerant circulation loop; 31. The fluorine pump; 32. The third one-way valve;

4、旁通支路;41、控制阀;4. Bypass branch; 41. Control valve;

5、换热水路。5. Change the hot water circuit.

具体实施方式Detailed ways

下面参照附图来描述本发明的优选实施方式。本领域技术人员应当理解的是,这些实施方式仅用于解释本发明的技术原理,并非旨在限制本发明的保护范围。本领域技术人员可以根据需要对其作出调整,以便适应具体的应用场合。例如,本发明中所述的复叠式热泵系统可以是家用复叠式热泵系统,也可是工业用复叠式热泵系统,这都不是限制性的,本领域技术人员可以根据实际使用需求自行设定本发明的复叠式热泵系统的应用场合。这种有关应用场合的改变并不偏离本发明的基本原理,属于本发明的保护范围。Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention. Those skilled in the art can adjust it as needed to adapt to specific applications. For example, the cascade heat pump system described in the present invention may be a domestic cascade heat pump system or an industrial cascade heat pump system, which is not limiting, and those skilled in the art can set their own according to actual use requirements. The application of the cascade heat pump system of the present invention is determined. Such changes in relevant application situations do not deviate from the basic principles of the present invention, and belong to the protection scope of the present invention.

需要说明的是,在本优选实施方式的描述中,除非另有明确的规定和限定,术语“第一”、“第二”、“第三”仅用于描述目的,而不能理解为指示或暗示相对重要性。此外,术语“相连”、“连接”应做广义理解,例如,可以是机械连接,也可以是电连接,可以是直接相连,也可以通过中间媒介间接相连,还可以是两个元件内部的相连,因此不能理解为对本发明的限制。对于本领域技术人员而言,可根据具体情况理解上述术语在本发明中的具体含义。It should be noted that, in the description of the present preferred embodiment, unless otherwise expressly specified and limited, the terms "first", "second" and "third" are only used for the purpose of description, and should not be construed as indicating or imply relative importance. In addition, the terms "connected" and "connected" should be understood in a broad sense, for example, it may be a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or an internal connection between two elements. , so it should not be construed as a limitation of the present invention. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

此外,还需要说明的是,在本发明的描述中,尽管本申请中按照特定顺序描述了本发明的控制方法的各个步骤,但是这些顺序并不是限制性的,在不偏离本发明的基本原理的前提下,本领域技术人员可以按照不同的顺序来执行所述步骤。In addition, it should be noted that, in the description of the present invention, although the various steps of the control method of the present invention are described in a specific order in the present application, these sequences are not restrictive, and do not deviate from the basic principle of the present invention. Under the premise that those skilled in the art can perform the steps in different orders.

基于背景技术中所提及的现有复叠式热泵系统容易受环境温度的影响而运行范围较窄的问题,本发明提供一种新的复叠式热泵系统及其控制方法,旨在通过选择性地运行第一低压冷媒循环回路、第二低压冷媒循环回路和旁通支路,以扩大复叠式热泵系统的运行范围,进而有效保证高压冷媒循环回路始终运行,以满足用户使用需求。Based on the problem that the existing cascade heat pump system is easily affected by the ambient temperature and has a narrow operating range mentioned in the background art, the present invention provides a new cascade heat pump system and a control method thereof. The first low-pressure refrigerant circulation loop, the second low-pressure refrigerant circulation loop and the bypass branch can be run stably to expand the operating range of the cascade heat pump system, thereby effectively ensuring that the high-pressure refrigerant circulation loop is always running to meet the needs of users.

首先参阅图1,图1是本发明的复叠式热泵系统的整体结构示意图。如图1所示,本发明的复叠式热泵系统包括高压冷媒循环回路1、第一低压冷媒循环回路2和第二低压冷媒循环回路3,高压冷媒循环回路1上设置有第一压缩机11、第一换热器12、第一节流构件13和中间换热器14,第一低压冷媒循环回路2上设置有第二压缩机21、中间换热器14、第二节流构件22和第二换热器23,第二低压冷媒循环回路3上设置有氟泵31、第二换热器23和中间换热器14,第一低压冷媒循环回路2和第二低压冷媒循环回路3设置成能够选择性地通过中间换热器14与高压冷媒循环回路1进行换热。Referring first to FIG. 1 , FIG. 1 is a schematic diagram of the overall structure of the cascade heat pump system of the present invention. As shown in FIG. 1 , the cascade heat pump system of the present invention includes a high-pressure refrigerant circulation circuit 1, a first low-pressure refrigerant circulation circuit 2 and a second low-pressure refrigerant circulation circuit 3, and the high-pressure refrigerant circulation circuit 1 is provided with a first compressor 11. , the first heat exchanger 12, the first throttling member 13 and the intermediate heat exchanger 14, the first low pressure refrigerant circulation circuit 2 is provided with a second compressor 21, the intermediate heat exchanger 14, the second throttling member 22 and The second heat exchanger 23, the second low pressure refrigerant circulation loop 3 is provided with a fluorine pump 31, the second heat exchanger 23 and the intermediate heat exchanger 14, the first low pressure refrigerant circulation loop 2 and the second low pressure refrigerant circulation loop 3 are provided It can selectively exchange heat with the high-pressure refrigerant circulation circuit 1 through the intermediate heat exchanger 14 .

基于上述结构设置,本发明的复叠式热泵系统通过选择性地运行第一低压冷媒循环回路2和第二低压冷媒循环回路3,有效保证高压冷媒循环回路1始终运行,进而既能够有效扩大所述复叠式热泵系统的运行范围,还能够有效降低所述复叠式热泵系统的运行能耗,提高用户使用体验感。Based on the above structural arrangement, the cascade heat pump system of the present invention effectively ensures that the high-pressure refrigerant circulation loop 1 is always running by selectively operating the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3, thereby effectively expanding the The operating range of the cascade heat pump system can also be effectively reduced, and the operating energy consumption of the cascade heat pump system can be effectively improved, and the user experience can be improved.

需要说明的是,本发明不对高压冷媒循环回路1、第一低压冷媒循环回路2和第二低压冷媒循环回路3中流动的冷媒的具体类型作任何限制,本领域技术人员可以根据实际情况自行设定。作为一种具体的实施方式,高压冷媒循环回路1中的冷媒为制冷剂R134a,第一低压冷媒循环回路2和第二低压冷媒循环回路3中的冷媒为制冷剂R410A。It should be noted that the present invention does not impose any restrictions on the specific types of refrigerants flowing in the high-pressure refrigerant circulating circuit 1, the first low-pressure refrigerant circulating circuit 2 and the second low-pressure refrigerant circulating circuit 3, and those skilled in the art can set their own according to the actual situation. Certainly. As a specific embodiment, the refrigerant in the high-pressure refrigerant circulation circuit 1 is refrigerant R134a, and the refrigerant in the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 is refrigerant R410A.

此外,还需要说明的是,本发明不对中间换热器14的具体结构作任何限制,其可以是壳管式换热器,也可以是板式换热器,本领域技术人员可以根据实际情况自行设定。在本具体实施方式中,中间换热器14优选为板式换热器,以有效提高第一低压冷媒循环回路2和第二低压冷媒循环回路3中的冷媒在中间换热器14中的换热效率。In addition, it should be noted that the present invention does not impose any restrictions on the specific structure of the intermediate heat exchanger 14, which can be a shell-and-tube heat exchanger or a plate-type heat exchanger, and those skilled in the art can make their own choices according to the actual situation. set up. In this specific embodiment, the intermediate heat exchanger 14 is preferably a plate heat exchanger, so as to effectively improve the heat exchange of the refrigerant in the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3 in the intermediate heat exchanger 14 efficiency.

优选地,第一低压冷媒循环回路2和第二低压冷媒循环回路3相连,以简化所述复叠式热泵系统的结构。如图1所示,氟泵31的两端与第一低压冷媒循环回路2相连,第二压缩机21的两端与第二低压冷媒循环回路3相连;具体地,氟泵31的第一端连接至第二节流构件22和第二换热器23之间,氟泵31的第二端连接至中间换热器14和第二节流构件22之间。中间换热器14包括第一换热通道和第二换热通道,第二换热器23包括第一换热管,其中,高压冷媒循环回路1中的冷媒流经所述第一换热通道,第一低压冷媒循环回路2和第二低压冷媒循环回路3中的冷媒流经所述第二换热通道和所述第一换热管,以达到换热的目的。Preferably, the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3 are connected to simplify the structure of the cascade heat pump system. As shown in FIG. 1 , both ends of the fluorine pump 31 are connected to the first low-pressure refrigerant circulation circuit 2, and both ends of the second compressor 21 are connected to the second low-pressure refrigerant circulation circuit 3; Connected between the second throttle member 22 and the second heat exchanger 23 , the second end of the fluorine pump 31 is connected between the intermediate heat exchanger 14 and the second throttle member 22 . The intermediate heat exchanger 14 includes a first heat exchange channel and a second heat exchange channel, and the second heat exchanger 23 includes a first heat exchange tube, wherein the refrigerant in the high-pressure refrigerant circulation circuit 1 flows through the first heat exchange channel , the refrigerants in the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3 flow through the second heat exchange channel and the first heat exchange tube to achieve the purpose of heat exchange.

需要说明的是,本发明不对第一压缩机11、第二压缩机21、氟泵31、第一节流构件13、第二节流构件22、第一换热器12和第二换热器23的具体结构和具体型号作任何限制;第一压缩机11和第二压缩机21可以是变频压缩机,也可以是定频压缩机,优选地,第一压缩机11和第二压缩机21是变频压缩机,以便控制所述复叠式热泵系统的运行状态;氟泵31可以是衬氟离心泵,也可以是衬氟磁力泵,还可以是衬氟自吸泵;第一节流构件13和第二节流构件22可以是电子膨胀阀,也可以是毛细管,还可以是热力膨胀阀;第一换热器12和第二换热器23可以是板式换热器,也可以是壳管式换热器,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not apply to the first compressor 11 , the second compressor 21 , the fluorine pump 31 , the first throttling member 13 , the second throttling member 22 , the first heat exchanger 12 and the second heat exchanger No limitation is imposed on the specific structure and specific model of 23; the first compressor 11 and the second compressor 21 may be variable frequency compressors or fixed frequency compressors, preferably, the first compressor 11 and the second compressor 21 is a variable frequency compressor to control the operating state of the cascade heat pump system; the fluorine pump 31 can be a fluorine-lined centrifugal pump, a fluorine-lined magnetic pump, or a fluorine-lined self-priming pump; the first throttling member 13 and the second throttling member 22 can be an electronic expansion valve, a capillary tube, or a thermal expansion valve; the first heat exchanger 12 and the second heat exchanger 23 can be a plate heat exchanger or a shell The tubular heat exchanger, which is not limiting, can be set by those skilled in the art according to the actual situation.

此外,还需要说明的是,本发明也不对第二换热器23的热源来源作任何限制,其可以是空气源,也可以是地源,这都不是限制性的,只要能够实现对第二换热器23的换热目的即可,本领域技术人员可以根据实际情况自行设定。在本优选实施例中,第二换热器23的热源是空气源,以进一步降低所述复叠式热泵系统的能耗,提高运行能效;具体地,所述复叠式热泵系统还包括换热风机(图中未示出),所述换热风机设置在第二换热器23的附近,以提高空气和第二换热器23中冷媒的换热效果。In addition, it should be noted that the present invention also does not impose any restrictions on the heat source source of the second heat exchanger 23, which can be an air source or a ground source, which is not limiting, as long as the second heat exchanger 23 can be realized The heat exchange purpose of the heat exchanger 23 is sufficient, and those skilled in the art can set it according to the actual situation. In this preferred embodiment, the heat source of the second heat exchanger 23 is an air source, so as to further reduce the energy consumption of the cascade heat pump system and improve the operation energy efficiency; specifically, the cascade heat pump system further includes a heat exchanger A hot air blower (not shown in the figure) is provided near the second heat exchanger 23 to improve the heat exchange effect between the air and the refrigerant in the second heat exchanger 23 .

进一步地,在本优选实施例中,所述复叠式热泵系统还包括旁通支路4,旁通支路4的第一端连接至氟泵31与第一低压冷媒循环回路2的连接点和第二换热器23之间,旁通支路4的第二端连接至第二压缩机21和中间换热器14之间,旁通支路4的设置能够进一步扩大所述复叠式热泵系统的运行范围,进而有效保证高压冷媒循环回路1能够始终运行,满足用户的实际需求。需要说明的是,本发明不对旁通支路4的第一端和第二端的具体连接位置作任何限制,本领域技术人员可以根据实际情况自行设定。Further, in this preferred embodiment, the cascade heat pump system further includes a bypass branch 4, and the first end of the bypass branch 4 is connected to the connection point between the fluorine pump 31 and the first low-pressure refrigerant circulation loop 2 and the second heat exchanger 23, the second end of the bypass branch 4 is connected between the second compressor 21 and the intermediate heat exchanger 14, the setting of the bypass branch 4 can further expand the cascade type The operating range of the heat pump system can effectively ensure that the high-pressure refrigerant circulation loop 1 can always operate to meet the actual needs of users. It should be noted that the present invention does not impose any restrictions on the specific connection positions of the first end and the second end of the bypass branch 4, and those skilled in the art can set them according to the actual situation.

优选地,旁通支路4上设置有控制阀41,控制阀41设置成能够控制旁通支路4的通断状态和冷媒流动方向。需要说明的是,本发明不对控制阀41的具体结构和类型作任何限制,本领域技术人员可以根据实际情况自行设定。Preferably, the bypass branch 4 is provided with a control valve 41, and the control valve 41 is set to be able to control the on-off state of the bypass branch 4 and the flow direction of the refrigerant. It should be noted that the present invention does not impose any restrictions on the specific structure and type of the control valve 41, and those skilled in the art can set it according to the actual situation.

作为一种具体的实施方式,控制阀41为换向控制阀,所述换向控制阀设置成通过换向控制既能够使旁通支路4中流动的冷媒由旁通支路4的第二端流向旁通支路4的第一端,也能够使旁通支路4中流动的冷媒由旁通支路4的第一端流向旁通支路4的第二端。As a specific embodiment, the control valve 41 is a reversing control valve, and the reversing control valve is configured to enable the refrigerant flowing in the bypass branch 4 to pass from the second side of the bypass branch 4 through the reversing control. The end flows to the first end of the bypass branch 4 , and the refrigerant flowing in the bypass branch 4 can also flow from the first end of the bypass branch 4 to the second end of the bypass branch 4 .

具体地,所述换向控制阀设置成在第一低压冷媒循环回路2运行且第二低压冷媒循环回路3不运行时,能够使第一低压冷媒循环回路2中流动的冷媒由旁通支路4的第二端流向旁通支路4的第一端。第一低压冷媒循环回路2中的冷媒从第二压缩机21的排气口排出后,一部分通过旁通支路4的第二端进入旁通支路4中,另一部分进入中间换热器14中与高压冷媒循环回路1中的冷媒进行换热,然后经过第二节流构件22节流降压后与旁通支路4的第一端流出的冷媒汇合后进入第二换热器23中,再由第二压缩机21的进气口回至第二压缩机21中。Specifically, the reversing control valve is configured to enable the refrigerant flowing in the first low-pressure refrigerant circulation circuit 2 to pass through the bypass branch when the first low-pressure refrigerant circulation circuit 2 is in operation and the second low-pressure refrigerant circulation circuit 3 is not in operation. The second end of 4 flows to the first end of the bypass branch 4 . After the refrigerant in the first low-pressure refrigerant circulation circuit 2 is discharged from the discharge port of the second compressor 21, a part enters the bypass branch 4 through the second end of the bypass branch 4, and the other part enters the intermediate heat exchanger 14 It exchanges heat with the refrigerant in the high-pressure refrigerant circulation circuit 1, and then passes through the second throttling member 22 to throttle and depressurize, and then merges with the refrigerant flowing out of the first end of the bypass branch 4 and enters the second heat exchanger 23. , and then return to the second compressor 21 from the air inlet of the second compressor 21 .

此外,所述换向控制阀还设置成在第一低压冷媒循环回路2不运行且第二低压冷媒循环回路3运行时,能够使第二低压冷媒循环回路3中流动的冷媒由旁通支路4的第一端流向旁通支路4的第二端。具体地,经由氟泵31循环出的冷媒一部分通过旁通支路4的第一端进入旁通支路4中,另一部分进入第二换热器23中蒸发吸热后与旁通支路4的第二端流出的冷媒汇合,然后进入中间换热器14中与高压冷媒循环回路1中的冷媒进行换热,换热后的冷媒再次进入氟泵31中参与循环。In addition, the reversing control valve is also configured to enable the refrigerant flowing in the second low-pressure refrigerant circulation circuit 3 to pass through the bypass branch when the first low-pressure refrigerant circulation circuit 2 is not in operation and the second low-pressure refrigerant circulation circuit 3 is in operation. The first end of 4 flows to the second end of the bypass branch 4 . Specifically, a part of the refrigerant circulated through the fluorine pump 31 enters the bypass branch 4 through the first end of the bypass branch 4 , and the other part enters the second heat exchanger 23 to evaporate and absorb heat and then communicate with the bypass branch 4 . The refrigerant flowing out of the second end of the refrigerant is combined, and then enters the intermediate heat exchanger 14 for heat exchange with the refrigerant in the high-pressure refrigerant circulation circuit 1, and the refrigerant after heat exchange enters the fluorine pump 31 again to participate in the circulation.

另外,在第一低压冷媒循环回路2和第二低压冷媒循环回路3均运行时,本领域技术人员可以通过控制所述换向控制阀的方向,进而控制旁通支路4中冷媒的流向,本发明对此不作任何限制。In addition, when both the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 are in operation, those skilled in the art can control the direction of the reversing control valve, thereby controlling the flow direction of the refrigerant in the bypass branch 4, The present invention does not make any limitation to this.

优选地,第一低压冷媒循环回路2上还设置有第一单向阀24,第一单向阀24设置在第二压缩机21和旁通支路4的第二端之间,第一单向阀24设置成仅允许冷媒从第二压缩机21的排气口的一侧流向旁通支路4的第二端和中间换热器14的一侧,第一单向阀24能够有效保证在第一低压冷媒循环回路2不运行且第二低压冷媒循环回路3运行时,旁通支路4的第二端流出的冷媒不会逆流至第二压缩机21中。Preferably, the first low-pressure refrigerant circulation circuit 2 is further provided with a first one-way valve 24, the first one-way valve 24 is disposed between the second compressor 21 and the second end of the bypass branch 4, and the first one-way valve 24 is provided. The check valve 24 is set to only allow the refrigerant to flow from the side of the discharge port of the second compressor 21 to the second end of the bypass branch 4 and the side of the intermediate heat exchanger 14. The first check valve 24 can effectively ensure that When the first low-pressure refrigerant circulation circuit 2 is not in operation and the second low-pressure refrigerant circulation circuit 3 is in operation, the refrigerant flowing out of the second end of the bypass branch 4 will not flow back into the second compressor 21 .

进一步地,第一低压冷媒循环回路2上还设置有第二单向阀25,第二单向阀25设置在旁通支路4的第一端和氟泵31与第一低压冷媒循环回路2的连接点之间,第二单向阀25设置成仅允许冷媒由氟泵31与第一低压冷媒循环回路2的连接点的一侧流向旁通支路4的第一端和第二换热器23的一侧,第二单向阀25能够有效保证在第一低压冷媒循环回路2运行且第二低压冷媒循环回路3不运行时,旁通支路4的第一端流出的冷媒不会逆流至氟泵31中。Further, the first low-pressure refrigerant circulation circuit 2 is also provided with a second one-way valve 25, and the second one-way valve 25 is arranged at the first end of the bypass branch 4 and the fluorine pump 31 and the first low-pressure refrigerant circulation circuit 2. Between the connection points, the second one-way valve 25 is set to only allow the refrigerant to flow from the side of the connection point between the fluorine pump 31 and the first low-pressure refrigerant circulation loop 2 to the first end of the bypass branch 4 and the second heat exchange On one side of the device 23, the second one-way valve 25 can effectively ensure that when the first low-pressure refrigerant circulation circuit 2 is running and the second low-pressure refrigerant circulation circuit 3 is not running, the refrigerant flowing out of the first end of the bypass branch 4 will not Backflow into the fluorine pump 31 .

进一步优选地,第二低压冷媒循环回路3上还设置有第三单向阀32,第三单向阀32设置在第二换热器23和中间换热器14之间,具体地,第三单向阀32与第二压缩机21呈并联设置,第三单向阀32设置成仅允许冷媒由第二换热器23的一侧流向中间换热器14的一侧。Further preferably, a third one-way valve 32 is also provided on the second low-pressure refrigerant circulation circuit 3, and the third one-way valve 32 is provided between the second heat exchanger 23 and the intermediate heat exchanger 14, specifically, the third one-way valve 32 The check valve 32 is arranged in parallel with the second compressor 21 , and the third check valve 32 is arranged to only allow the refrigerant to flow from the side of the second heat exchanger 23 to the side of the intermediate heat exchanger 14 .

需要说明的是,本发明不对第一单向阀24、第二单向阀25和第三单向阀32的具体结构和型号作任何限制,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not limit the specific structures and models of the first one-way valve 24, the second one-way valve 25 and the third one-way valve 32, which can be set by those skilled in the art according to actual conditions.

此外,在本优选实施例中,所述复叠式热泵系统还包括换热水路5,换热水路5的一部分设置于第一换热器12中以与高压冷媒循环回路1中的冷媒进行换热。需要说明的是,本发明不对换热水路5的具体结构作任何限制,本领域技术人员可以根据实际情况自行设定。In addition, in this preferred embodiment, the cascade heat pump system further includes a hot water exchange circuit 5, and a part of the hot water exchange circuit 5 is arranged in the first heat exchanger 12 to exchange with the refrigerant in the high-pressure refrigerant circulation circuit 1 hot. It should be noted that the present invention does not impose any restrictions on the specific structure of the hot water exchange circuit 5, and those skilled in the art can set it according to the actual situation.

进一步地,高压冷媒循环回路1上还设置有第一气分装置(图中未示出),所述第一气分装置设置于第一压缩机11的进气口处。第一低压冷媒循环回路2上还设置有第二气分装置(图中未示出),所述第二气分装置设置于第二压缩机21的进气口处。所述第一气分装置和所述第二气分装置的设置能够有效避免第一压缩机11和第二压缩机21出现液击的问题,有效保证第一压缩机11和第二压缩机21的使用寿命。需要说明的是,本发明不对所述第一气分装置和所述第二气分装置的具体结构作任何限制,本领域技术人员可以根据实际情况自行设定。Further, the high-pressure refrigerant circulation circuit 1 is also provided with a first air separation device (not shown in the figure), and the first air separation device is arranged at the air inlet of the first compressor 11 . The first low-pressure refrigerant circulation loop 2 is also provided with a second air separation device (not shown in the figure), and the second air separation device is arranged at the air inlet of the second compressor 21 . The arrangement of the first air separation device and the second air separation device can effectively avoid the problem of liquid hammer in the first compressor 11 and the second compressor 21, and effectively ensure the first compressor 11 and the second compressor 21. service life. It should be noted that the present invention does not impose any restrictions on the specific structures of the first gas separation device and the second gas separation device, and those skilled in the art can set them according to actual conditions.

进一步地,所述复叠式热泵系统还包括温度传感器、压力传感器和控制器,所述温度传感器用于检测环境温度、中间换热器14的当前冷媒蒸发温度和第二换热器23的出口处的冷媒温度,所述压力传感器用于检测第一压缩机11的当前吸气压力。需要说明的是,本发明不对所述温度传感器和所述压力传感器的具体结构、型号、设置数量和设置位置作任何限制,本领域技术人员可以根据实际情况自行设定。Further, the cascade heat pump system also includes a temperature sensor, a pressure sensor and a controller, the temperature sensor is used to detect the ambient temperature, the current refrigerant evaporation temperature of the intermediate heat exchanger 14 and the outlet of the second heat exchanger 23 The temperature of the refrigerant at the first compressor 11 is used to detect the current suction pressure of the first compressor 11 . It should be noted that the present invention does not impose any restrictions on the specific structure, model, number and location of the temperature sensor and the pressure sensor, which can be set by those skilled in the art according to the actual situation.

所述控制器能够控制所述复叠式热泵系统的运行状态,例如,所述控制器可以控制第一低压冷媒循环回路2、第二低压冷媒循环回路3和旁通支路4的运行状态,所述控制器还能够获取所述温度传感器和所述压力传感器的检测结果等,这都不是限制性的。本领域技术人员能够理解的是,本发明不对所述控制器的具体结构和型号作任何限制,并且所述控制器既可以是所述复叠式热泵系统原有的控制器,也可以是为执行本发明的控制方法单独设置的控制器,本领域技术人员可以根据实际使用需求自行设定所述控制器的结构和型号。The controller can control the operation state of the cascade heat pump system, for example, the controller can control the operation state of the first low-pressure refrigerant circulation circuit 2, the second low-pressure refrigerant circulation circuit 3 and the bypass branch 4, The controller can also acquire the detection results of the temperature sensor and the pressure sensor, etc., which are not limitative. It can be understood by those skilled in the art that the present invention does not limit the specific structure and model of the controller, and the controller may be the original controller of the cascade heat pump system, or the controller For a controller set separately for implementing the control method of the present invention, those skilled in the art can set the structure and model of the controller by themselves according to actual use requirements.

首先参阅图2,图2是本发明的控制方法的主要步骤流程图。如图2所示,基于上述实施例中所述的复叠式热泵系统,本发明的控制方法主要包括下列步骤:Referring first to FIG. 2, FIG. 2 is a flow chart of the main steps of the control method of the present invention. As shown in FIG. 2, based on the cascade heat pump system described in the above embodiment, the control method of the present invention mainly includes the following steps:

S1:获取复叠式热泵系统所处的环境温度;S1: Obtain the ambient temperature where the cascade heat pump system is located;

S2:根据环境温度,控制第一低压冷媒循环回路和第二低压冷媒循环回路的运行状态;S2: Control the operating states of the first low-pressure refrigerant circulation loop and the second low-pressure refrigerant circulation loop according to the ambient temperature;

S3:获取高压冷媒循环回路的运行参数;S3: Obtain the operating parameters of the high-pressure refrigerant circulation loop;

S4:根据高压冷媒循环回路的运行参数,控制旁通支路的运行状态。S4: Control the operating state of the bypass branch according to the operating parameters of the high-pressure refrigerant circulation loop.

首先,在步骤S1中,所述控制器获取所述温度传感器检测的所述复叠式热泵系统所处的环境温度;当然,本发明并不对所述环境温度的具体获取时机以及获取方式作任何限制,所述控制器可以实时获取,也可以间隔一定的时长获取,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。优选地,所述控制器实时获取所述环境温度,以便能够及时有效地对所述复叠式热泵系统的运行状态进行调整,进而有效提高所述复叠式热泵系统的运行能效,扩大所述复叠式热泵系统的运行范围。First, in step S1, the controller acquires the ambient temperature of the cascade heat pump system detected by the temperature sensor; of course, the present invention does not make any specific acquisition timing and acquisition method of the ambient temperature. Restriction, the controller may acquire in real time, or acquire in a certain period of time, which is not restrictive, and those skilled in the art can set by themselves according to the actual situation. Preferably, the controller acquires the ambient temperature in real time, so as to be able to adjust the operating state of the cascade heat pump system in a timely and effective manner, thereby effectively improving the operating energy efficiency of the cascade heat pump system and expanding the The operating range of the cascade heat pump system.

接着,在步骤S2中,所述控制器根据所述环境温度,控制第一低压冷媒循环回路2和第二低压冷媒循环回路3的运行状态。Next, in step S2, the controller controls the operating states of the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 according to the ambient temperature.

需要说明的是,本发明不对步骤S2的具体控制逻辑作任何限制,所述控制器可以根据所述环境温度控制第一低压冷媒循环回路2和第二低压冷媒循环回路3的通断状态,也可以控制第一低压冷媒循环回路2和第二低压冷媒循环回路3中冷媒的运行速度,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not impose any restrictions on the specific control logic of step S2, and the controller can control the on-off state of the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3 according to the ambient temperature, and also The operating speeds of the refrigerants in the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 can be controlled, which are not limiting, and can be set by those skilled in the art according to actual conditions.

进一步地,在步骤S3中,所述控制器获取高压冷媒循环回路1的运行参数;当然,本发明不对获取的高压冷媒循环回路1的运行参数的具体参数类型作任何限制,其可以是第一压缩机11的运行频率,也可以是第一压缩机11的排气压力或吸气压力等,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。Further, in step S3, the controller obtains the operating parameters of the high-pressure refrigerant circulating circuit 1; of course, the present invention does not limit the specific parameter types of the obtained operating parameters of the high-pressure refrigerant circulating circuit 1, which may be the first The operating frequency of the compressor 11 may also be the discharge pressure or the suction pressure of the first compressor 11, etc., which are not limiting, and can be set by those skilled in the art according to the actual situation.

接着,在步骤S4中,所述控制器根据高压冷媒循环回路1的运行参数控制旁通支路4的运行状态。Next, in step S4 , the controller controls the operating state of the bypass branch 4 according to the operating parameters of the high-pressure refrigerant circulation circuit 1 .

需要说明的是,本发明不对步骤S4的具体控制逻辑作任何限制,所述控制器可以根据高压冷媒循环回路1的运行参数控制旁通支路4的通断状态,也可以根据高压冷媒循环回路1的运行参数通过控制控制阀41的开度,进而控制旁通支路4的运行状态,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not impose any restrictions on the specific control logic of step S4. The controller can control the on-off state of the bypass branch 4 according to the operating parameters of the high-pressure refrigerant circulation loop 1, and can also control the on-off state of the bypass branch 4 according to the operating parameters of the high-pressure refrigerant circulation loop The operating parameters of 1 are controlled by controlling the opening of the control valve 41, thereby controlling the operating state of the bypass branch 4, which are not restrictive, and can be set by those skilled in the art according to the actual situation.

此外,还需要说明的是,本发明不对步骤S1和步骤S3的具体执行顺序作任何限制,且可以同时执行,也可以不分任何顺序地先后执行,本领域技术人员根据实际情况自行设定。In addition, it should be noted that the present invention does not impose any restrictions on the specific execution order of step S1 and step S3, and can be executed simultaneously or sequentially without any order, which can be set by those skilled in the art according to the actual situation.

接着参阅图3,图3是本发明的控制方法的第一优选实施例的具体步骤流程图。如图3所示,基于上述实施例中所述的复叠式热泵系统,本发明的第一优选实施例的控制方法的包括下列步骤:Next, referring to FIG. 3 , FIG. 3 is a flow chart of the specific steps of the first preferred embodiment of the control method of the present invention. As shown in FIG. 3, based on the cascade heat pump system described in the above embodiments, the control method of the first preferred embodiment of the present invention includes the following steps:

S101:获取复叠式热泵系统所处的环境温度;S101: Obtain the ambient temperature where the cascade heat pump system is located;

S102:如果环境温度大于或等于预设环境温度,则控制第一低压冷媒循环回路不运行,且控制第二低压冷媒循环回路运行;S102: if the ambient temperature is greater than or equal to the preset ambient temperature, control the first low-pressure refrigerant circulation circuit to not operate, and control the second low-pressure refrigerant circulation circuit to operate;

S103:如果环境温度小于预设环境温度,则控制第一低压冷媒循环回路运行,且控制第二低压冷媒循环回路不运行;S103: if the ambient temperature is lower than the preset ambient temperature, control the first low-pressure refrigerant circulation loop to operate, and control the second low-pressure refrigerant circulation loop to not operate;

S104:获取中间换热器的当前冷媒蒸发温度和最大冷媒蒸发温度;S104: Obtain the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature of the intermediate heat exchanger;

S105:计算最大冷媒蒸发温度和当前冷媒蒸发温度的差值,记为第一差值;S105: Calculate the difference between the maximum refrigerant evaporation temperature and the current refrigerant evaporation temperature, and record it as the first difference;

S106:如果第一差值小于第一预设差值,则控制旁通支路运行;S106: if the first difference is less than the first preset difference, control the bypass branch to operate;

S107:如果第一差值大于或等于第一预设差值,则控制旁通支路不运行。S107: If the first difference is greater than or equal to the first preset difference, control the bypass branch not to operate.

首先,在步骤S101中,所述控制器获取所述温度传感器检测的所述复叠式热泵系统所处的环境温度;当然,本发明并不对所述环境温度的具体获取时机以及获取方式作任何限制,所述控制器可以实时获取,也可以间隔一定的时长获取,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。优选地,所述控制器实时获取所述环境温度,以便能够及时有效地对所述复叠式热泵系统的运行状态进行调整,进而有效提高所述复叠式热泵系统的运行能效,扩大所述复叠式热泵系统的运行范围。First, in step S101, the controller acquires the ambient temperature of the cascade heat pump system detected by the temperature sensor; of course, the present invention does not make any specific acquisition timing and acquisition method of the ambient temperature. Restriction, the controller may acquire in real time, or acquire in a certain period of time, which is not restrictive, and those skilled in the art can set by themselves according to the actual situation. Preferably, the controller acquires the ambient temperature in real time, so as to be able to adjust the operating state of the cascade heat pump system in a timely and effective manner, thereby effectively improving the operating energy efficiency of the cascade heat pump system and expanding the The operating range of the cascade heat pump system.

接着,所述控制器根据所述环境温度,控制第一低压冷媒循环回路2和第二低压冷媒循环回路3的运行状态。Next, the controller controls the operating states of the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 according to the ambient temperature.

需要说明的是,本发明不对上述步骤的具体控制逻辑作任何限制,所述控制器可以根据所述环境温度控制第一低压冷媒循环回路2和第二低压冷媒循环回路3的通断状态,也可以控制第一低压冷媒循环回路2和第二低压冷媒循环回路3中冷媒的运行速度,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not impose any restrictions on the specific control logic of the above steps, and the controller can control the on-off state of the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3 according to the ambient temperature, and also The operating speeds of the refrigerants in the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 can be controlled, which are not limiting, and can be set by those skilled in the art according to actual conditions.

优选地,在步骤S102中,如果所述环境温度大于或等于所述预设环境温度,则所述控制器控制第一低压冷媒循环回路2不运行,且控制第二低压冷媒循环回路3运行,以便有效降低所述复叠式热泵系统的运行能耗。Preferably, in step S102, if the ambient temperature is greater than or equal to the preset ambient temperature, the controller controls the first low-pressure refrigerant circulation circuit 2 to not operate, and controls the second low-pressure refrigerant circulation circuit 3 to operate, In order to effectively reduce the operating energy consumption of the cascade heat pump system.

进一步地,在步骤S103中,如果所述环境温度小于所述预设环境温度,则所述控制器控制第一低压冷媒循环回路2运行,且控制第二低压冷媒循环回路3不运行,以便有效保证中间换热器14的换热量能够使高压冷媒循环回路1正常运行,以满足用户的使用需求。Further, in step S103, if the ambient temperature is lower than the preset ambient temperature, the controller controls the first low-pressure refrigerant circulation loop 2 to operate, and controls the second low-pressure refrigerant circulation loop 3 to not operate, so as to effectively It is ensured that the heat exchange of the intermediate heat exchanger 14 can make the high-pressure refrigerant circulation circuit 1 operate normally, so as to meet the user's use requirements.

需要说明的是,本发明不对所述预设环境温度的具体设定值作任何限制,本领域技术人员可以根据所述复叠式热泵系统的实际运行情况设定,也可以根据用户的实际使用需求获取,这都不是限制性的。It should be noted that the present invention does not impose any restrictions on the specific set value of the preset ambient temperature. Those skilled in the art can set it according to the actual operation of the cascade heat pump system, or according to the actual use of the user. Demand acquisition, which is not restrictive.

进一步优选地,在步骤S104中,所述控制器获取所述温度传感器检测到的中间换热器14的当前冷媒蒸发温度和最大冷媒蒸发温度。需要说明的是,本发明不对所述当前冷媒蒸发温度的具体获取时机和获取方式作任何限制,本领域技术人员可以根据实际情况自行设定。Further preferably, in step S104, the controller acquires the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature of the intermediate heat exchanger 14 detected by the temperature sensor. It should be noted that the present invention does not impose any restrictions on the specific acquisition timing and acquisition method of the current refrigerant evaporation temperature, and those skilled in the art can set it according to the actual situation.

接着,所述控制器根据所述当前冷媒蒸发温度和所述最大冷媒蒸发温度,控制旁通支路4的运行状态;当然,本发明不对本步骤的具体控制逻辑作任何限制,例如,所述控制器可以将所述当前冷媒蒸发温度和所述最大冷媒蒸发温度进行大小比较,并根据大小比较结果控制旁通支路4的运行状态。Next, the controller controls the operation state of the bypass branch 4 according to the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature; of course, the present invention does not impose any restrictions on the specific control logic of this step, for example, the The controller may compare the current evaporation temperature of the refrigerant with the maximum evaporation temperature of the refrigerant, and control the operation state of the bypass branch 4 according to the result of the comparison.

优选地,在步骤S105中,所述控制器计算所述最大冷媒蒸发温度和所述当前冷媒蒸发温度的差值,记为第一差值。Preferably, in step S105, the controller calculates the difference between the maximum refrigerant evaporation temperature and the current refrigerant evaporation temperature, which is recorded as the first difference.

接着,所述控制器根据所述第一差值,控制旁通支路4的运行状态。具体地,在步骤S106中,如果所述第一差值小于所述第一预设差值,说明此时所述当前冷媒蒸发温度接近所述最大冷媒蒸发温度,第一压缩机11存在因进气温度过高而停机进而导致高压冷媒循环回路1不运行的风险,则所述控制器控制旁通支路4运行,以通过降低中间换热器14的冷媒冷凝温度降低中间换热器14的冷媒蒸发温度,进而有效保证高压冷媒循环回路1能够正常运行。Next, the controller controls the operation state of the bypass branch 4 according to the first difference value. Specifically, in step S106, if the first difference is smaller than the first preset difference, it means that the current refrigerant evaporation temperature is close to the maximum refrigerant evaporation temperature at this time, and the first compressor 11 has a malfunction due to If the air temperature is too high and shut down, thereby causing the risk that the high-pressure refrigerant circulation circuit 1 does not operate, the controller controls the operation of the bypass branch 4 to reduce the refrigerant condensation temperature of the intermediate heat exchanger 14. Refrigerant evaporation temperature, thereby effectively ensuring the normal operation of the high-pressure refrigerant circulation circuit 1.

进一步地,在步骤S107,如果所述第一差值大于或等于所述第一预设差值,说明此时所述当前冷媒蒸发温度与所述最大冷媒蒸发温度相差较大,所述当前冷媒蒸发温度不会导致第一压缩机11因进气温度过高而停机进而导致高压冷媒循环回路1不运行的问题,则所述控制器控制旁通支路4不运行,以提高所述复叠式热泵系统的运行效率。Further, in step S107, if the first difference is greater than or equal to the first preset difference, it means that the difference between the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature is large, and the current refrigerant evaporation temperature The evaporating temperature will not cause the first compressor 11 to stop due to the high intake air temperature and thus cause the high-pressure refrigerant circulation circuit 1 to not operate, then the controller controls the bypass branch 4 to not operate, so as to improve the overlap efficiency of the heat pump system.

需要说明的是,本发明不对所述第一预设差值的具体设定值作任何限制,本领域技术人员可以根据所述复叠式热泵系统的实际运行情况设定,也可以根据用户的实际使用需求获取,这都不是限制性的;优选地,所述第一预设差值为1℃,以最大程度保证高压冷媒循环回路1高效运行。It should be noted that the present invention does not impose any restrictions on the specific set value of the first preset difference. Those skilled in the art can set it according to the actual operation of the cascade heat pump system, or set it according to the user's The acquisition of actual use requirements is not limiting; preferably, the first preset difference is 1° C. to ensure the efficient operation of the high-pressure refrigerant circulation loop 1 to the greatest extent.

此外,还需要说明的是,本发明不对步骤S101和步骤S104的具体执行顺序作任何限制,且可以同时执行,也可以不分任何顺序地先后执行,本领域技术人员根据实际情况自行设定。In addition, it should be noted that the present invention does not impose any restrictions on the specific execution order of step S101 and step S104, and can be executed simultaneously or sequentially without any order, and those skilled in the art can set it according to the actual situation.

接着参阅图4,图4是本发明的控制方法的第二优选实施例的具体步骤流程图。如图4所示,基于上述实施例中所述的复叠式热泵系统,本发明的第二优选实施例的控制方法的包括下列步骤:Next, referring to FIG. 4 , FIG. 4 is a flow chart of the specific steps of the second preferred embodiment of the control method of the present invention. As shown in FIG. 4 , based on the cascade heat pump system described in the above embodiments, the control method of the second preferred embodiment of the present invention includes the following steps:

S201:获取复叠式热泵系统所处的环境温度;S201: Obtain the ambient temperature where the cascade heat pump system is located;

S202:如果环境温度大于或等于预设环境温度,则控制第一低压冷媒循环回路不运行,且控制第二低压冷媒循环回路运行;S202: if the ambient temperature is greater than or equal to the preset ambient temperature, control the first low-pressure refrigerant circulation circuit to not operate, and control the second low-pressure refrigerant circulation circuit to operate;

S203:如果环境温度小于预设环境温度,则控制第一低压冷媒循环回路运行,且控制第二低压冷媒循环回路不运行;S203: if the ambient temperature is lower than the preset ambient temperature, control the first low-pressure refrigerant circulation loop to operate, and control the second low-pressure refrigerant circulation loop to not operate;

S204:获取第一压缩机的当前吸气压力和最大吸气压力;S204: Obtain the current suction pressure and the maximum suction pressure of the first compressor;

S205:计算最大吸气压力和当前吸气压力的差值,记为第二差值;S205: Calculate the difference between the maximum suction pressure and the current suction pressure, and record it as the second difference;

S206:如果第二差值小于第二预设差值,则控制旁通支路运行;S206: if the second difference is less than the second preset difference, control the bypass branch to operate;

S207:如果第二差值大于或等于第二预设差值,则控制旁通支路不运行。S207: If the second difference is greater than or equal to the second preset difference, control the bypass branch to not operate.

首先,在步骤S201中,所述控制器获取所述温度传感器检测的所述复叠式热泵系统所处的环境温度;当然,本发明并不对所述环境温度的具体获取时机以及获取方式作任何限制,所述控制器可以实时获取,也可以间隔一定的时长获取,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。优选地,所述控制器实时获取所述环境温度,以便能够及时有效地对所述复叠式热泵系统的运行状态进行调整,进而有效提高所述复叠式热泵系统的运行能效,扩大所述复叠式热泵系统的运行范围。First, in step S201, the controller acquires the ambient temperature of the cascade heat pump system detected by the temperature sensor; of course, the present invention does not make any specific acquisition timing and acquisition method of the ambient temperature. Restriction, the controller may acquire in real time, or acquire in a certain period of time, which is not restrictive, and those skilled in the art can set by themselves according to the actual situation. Preferably, the controller acquires the ambient temperature in real time, so as to be able to adjust the operating state of the cascade heat pump system in a timely and effective manner, thereby effectively improving the operating energy efficiency of the cascade heat pump system and expanding the The operating range of the cascade heat pump system.

接着,所述控制器根据所述环境温度,控制第一低压冷媒循环回路2和第二低压冷媒循环回路3的运行状态。Next, the controller controls the operating states of the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 according to the ambient temperature.

需要说明的是,本发明不对上述步骤的具体控制逻辑作任何限制,所述控制器可以根据所述环境温度控制第一低压冷媒循环回路2和第二低压冷媒循环回路3的通断状态,也可以控制第一低压冷媒循环回路2和第二低压冷媒循环回路3中冷媒的运行速度,这都不是限制性的,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not impose any restrictions on the specific control logic of the above steps, and the controller can control the on-off state of the first low-pressure refrigerant circulation loop 2 and the second low-pressure refrigerant circulation loop 3 according to the ambient temperature, and also The operating speeds of the refrigerants in the first low-pressure refrigerant circulation circuit 2 and the second low-pressure refrigerant circulation circuit 3 can be controlled, which are not limiting, and can be set by those skilled in the art according to actual conditions.

优选地,在步骤S202中,如果所述环境温度大于或等于所述预设环境温度,则所述控制器控制第一低压冷媒循环回路2不运行,且控制第二低压冷媒循环回路3运行,以便有效降低所述复叠式热泵系统的运行能耗。Preferably, in step S202, if the ambient temperature is greater than or equal to the preset ambient temperature, the controller controls the first low-pressure refrigerant circulation circuit 2 to not operate, and controls the second low-pressure refrigerant circulation circuit 3 to operate, In order to effectively reduce the operating energy consumption of the cascade heat pump system.

进一步地,在步骤S203中,如果所述环境温度小于所述预设环境温度,则所述控制器控制第一低压冷媒循环回路2运行,且控制第二低压冷媒循环回路3不运行,以便有效保证中间换热器14的换热量能够使高压冷媒循环回路1正常运行,以满足用户的使用需求。Further, in step S203, if the ambient temperature is lower than the preset ambient temperature, the controller controls the first low-pressure refrigerant circulation circuit 2 to operate, and controls the second low-pressure refrigerant circulation circuit 3 to not operate, so as to effectively It is ensured that the heat exchange of the intermediate heat exchanger 14 can make the high-pressure refrigerant circulation circuit 1 operate normally, so as to meet the user's use requirements.

需要说明的是,本发明不对所述预设环境温度的具体设定值作任何限制,本领域技术人员可以根据所述复叠式热泵系统的实际运行情况设定,也可以根据用户的实际使用需求获取,这都不是限制性的。It should be noted that the present invention does not impose any restrictions on the specific set value of the preset ambient temperature. Those skilled in the art can set it according to the actual operation of the cascade heat pump system, or according to the actual use of the user. Demand acquisition, which is not restrictive.

进一步优选地,在步骤S204中,所述控制器获取所述压力传感器检测到的第一压缩机11的当前吸气压力和最大吸气压力。需要说明的是,本发明不对所述当前吸气压力的具体获取时机和获取方式作任何限制,本领域技术人员可以根据实际情况自行设定。Further preferably, in step S204, the controller acquires the current suction pressure and the maximum suction pressure of the first compressor 11 detected by the pressure sensor. It should be noted that the present invention does not impose any restrictions on the specific acquisition timing and acquisition method of the current inspiratory pressure, and those skilled in the art can set it according to the actual situation.

接着,所述控制器根据所述当前吸气压力和所述最大吸气压力,控制旁通支路4的运行状态;当然,本发明不对本步骤的具体控制逻辑作任何限制,例如,所述控制器可以将所述当前吸气压力和所述最大吸气压力进行大小比较,并根据大小比较结果控制旁通支路4的运行状态。Next, the controller controls the operating state of the bypass branch 4 according to the current suction pressure and the maximum suction pressure; of course, the present invention does not limit the specific control logic of this step, for example, the The controller may compare the current suction pressure with the maximum suction pressure, and control the operating state of the bypass branch 4 according to the result of the magnitude comparison.

优选地,在步骤S205中,所述控制器计算所述最大吸气压力和所述当前吸气压力的差值,记为第二差值。Preferably, in step S205, the controller calculates the difference between the maximum suction pressure and the current suction pressure, which is recorded as a second difference.

接着,所述控制器根据所述第二差值,控制旁通支路4的运行状态。具体地,在步骤S206中,如果所述第二差值小于所述第二预设差值,说明此时所述当前吸气压力接近所述最大吸气压力,第一压缩机11存在因吸气压力过高而停机进而导致高压冷媒循环回路1不运行的风险,则所述控制器控制旁通支路4运行,以通过降低中间换热器14的冷媒冷凝温度降低中间换热器14的冷媒蒸发温度,进而降低第一压缩机11的吸气压力,保证高压冷媒循环回路1能够正常运行。Next, the controller controls the operating state of the bypass branch 4 according to the second difference. Specifically, in step S206, if the second difference is smaller than the second preset difference, it means that the current suction pressure is close to the maximum suction pressure at this time, and the first compressor 11 has suction due to suction. If the gas pressure is too high and shut down, resulting in the risk that the high-pressure refrigerant circulation circuit 1 does not operate, the controller controls the operation of the bypass branch 4 to reduce the condensation temperature of the intermediate heat exchanger 14 by reducing the refrigerant condensation temperature of the intermediate heat exchanger 14. The evaporation temperature of the refrigerant, thereby reducing the suction pressure of the first compressor 11, ensures that the high-pressure refrigerant circulation circuit 1 can operate normally.

进一步地,在步骤S207,如果所述第二差值大于或等于所述第二预设差值,说明此时所述当前吸气压力与所述最大吸气压力相差较大,第一压缩机11能够正常运行,则所述控制器控制旁通支路4不运行,以提高所述复叠式热泵系统的运行效率。Further, in step S207, if the second difference is greater than or equal to the second preset difference, it means that the difference between the current suction pressure and the maximum suction pressure is large, and the first compressor 11 can operate normally, the controller controls the bypass branch 4 to not operate, so as to improve the operation efficiency of the cascade heat pump system.

需要说明的是,本发明不对所述第二预设差值的具体设定值作任何限制,本领域技术人员可以根据所述复叠式热泵系统的实际运行情况设定,也可以根据用户的实际使用需求获取,这都不是限制性的。It should be noted that the present invention does not impose any restrictions on the specific set value of the second preset difference. Those skilled in the art can set it according to the actual operation of the cascade heat pump system, or set it according to the user's The actual use needs to be obtained, which are not restrictive.

此外,还需要说明的是,本发明不对步骤S201和步骤S204的具体执行顺序作任何限制,且可以同时执行,也可以不分任何顺序地先后执行,本领域技术人员根据实际情况自行设定。In addition, it should be noted that the present invention does not impose any restrictions on the specific execution order of step S201 and step S204, and can be executed simultaneously or sequentially without any order, and those skilled in the art can set it according to the actual situation.

此外,在第一低压冷媒循环回路1运行且旁通支路4不运行的情形下,即,在第一低压冷媒循环回路1运行且所述第一差值大于或等于所述第一预设差值或所述第二差值大于或等于所述第二预设差值的情形下,本发明的控制方法还包括获取第二换热器23出口处的冷媒温度,并根据第二换热器23出口处的冷媒温度,进一步控制旁通支路4的运行状态,以有效避免第二换热器23结霜,甚至冻裂的问题。In addition, in the case where the first low-pressure refrigerant circulation circuit 1 operates and the bypass branch 4 does not operate, that is, when the first low-pressure refrigerant circulation circuit 1 operates and the first difference value is greater than or equal to the first preset When the difference or the second difference is greater than or equal to the second preset difference, the control method of the present invention further includes acquiring the temperature of the refrigerant at the outlet of the second heat exchanger The temperature of the refrigerant at the outlet of the heat exchanger 23 is further controlled to further control the operation state of the bypass branch 4, so as to effectively avoid the problem of frosting or even cracking of the second heat exchanger 23.

需要说明的是,本发明不对第二换热器23出口处的冷媒温度的具体获取时机和获取方式作任何限制,也不对上述步骤的具体控制逻辑作任何限制,本领域技术人员可以根据实际情况自行设定。It should be noted that the present invention does not impose any restrictions on the specific acquisition timing and acquisition method of the refrigerant temperature at the outlet of the second heat exchanger 23, nor does it impose any restrictions on the specific control logic of the above steps. Set by yourself.

优选地,如果第二换热器23出口处的冷媒温度小于或等于所述预设冷媒温度,则所述控制器控制旁通支路4运行,以使第二压缩机21的排气口流出的冷媒通过旁通支路4直接进入第二换热器23中,进而有效避免第二换热器23因温度过低而结霜甚至冻裂的问题。Preferably, if the temperature of the refrigerant at the outlet of the second heat exchanger 23 is less than or equal to the preset refrigerant temperature, the controller controls the bypass branch 4 to operate so that the discharge port of the second compressor 21 flows out The refrigerant directly enters the second heat exchanger 23 through the bypass branch 4, thereby effectively avoiding the problem that the second heat exchanger 23 is frosted or even cracked due to the low temperature.

进一步地,如果第二换热器23出口处的冷媒温度大于所述预设冷媒温度,则所述控制器控制旁通支路4不运行,以有效保证所述复叠式热泵系统的运行能效。Further, if the refrigerant temperature at the outlet of the second heat exchanger 23 is greater than the preset refrigerant temperature, the controller controls the bypass branch 4 to not operate, so as to effectively ensure the operating energy efficiency of the cascade heat pump system. .

需要说明的是,本发明不对所述预设冷媒温度的具体设定值作任何限制,本领域技术人员可以根据所述复叠式热泵系统的实际运行情况自行设定。It should be noted that the present invention does not impose any restrictions on the specific set value of the preset refrigerant temperature, and those skilled in the art can set it by themselves according to the actual operation of the cascade heat pump system.

至此,已经结合附图所示的优选实施方式描述了本发明的技术方案,但是,本领域技术人员容易理解的是,本发明的保护范围显然不局限于这些具体实施方式。在不偏离本发明的原理的前提下,本领域技术人员可以对相关技术特征作出等同的更改或替换,这些更改或替换之后的技术方案都将落入本发明的保护范围之内。So far, the technical solutions of the present invention have been described with reference to the preferred embodiments shown in the accompanying drawings, however, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims (10)

1. A control method of a cascade heat pump system is characterized in that the cascade heat pump system comprises a high-pressure refrigerant circulation loop, a first low-pressure refrigerant circulation loop, a second low-pressure refrigerant circulation loop and a bypass branch,
the high-pressure refrigerant circulating loop is provided with a first compressor, a first heat exchanger, a first throttling component and an intermediate heat exchanger, the first low-pressure refrigerant circulating loop is provided with a second compressor, the intermediate heat exchanger, a second throttling component and a second heat exchanger, the second low-pressure refrigerant circulating loop is provided with a fluorine pump, a second heat exchanger and the intermediate heat exchanger, two ends of the fluorine pump are connected with the first low-pressure refrigerant circulating loop, two ends of the second compressor are connected with the second low-pressure refrigerant circulating loop, the first low-pressure refrigerant circulating loop and the second low-pressure refrigerant circulating loop are arranged to be capable of selectively exchanging heat with the high-pressure refrigerant circulating loop through the intermediate heat exchanger,
a first end of the bypass branch is connected between a connection point of the fluorine pump and the first low-pressure refrigerant circulation loop and the second heat exchanger, a second end of the bypass branch is connected between the second compressor and the intermediate heat exchanger, a control valve is arranged on the bypass branch and can control the on-off state of the bypass branch,
the control method comprises the following steps:
acquiring the ambient temperature of the cascade heat pump system;
controlling the running states of the first low-pressure refrigerant circulating loop and the second low-pressure refrigerant circulating loop according to the environment temperature;
acquiring operation parameters of the high-pressure refrigerant circulation loop;
and controlling the running state of the bypass branch according to the running parameters of the high-pressure refrigerant circulating loop.
2. The control method according to claim 1, wherein the step of controlling the operation states of the first and second low-pressure refrigerant circulation circuits according to the ambient temperature includes:
and if the ambient temperature is greater than or equal to a preset ambient temperature, controlling the first low-pressure refrigerant circulation loop not to operate, and controlling the second low-pressure refrigerant circulation loop to operate.
3. The control method as claimed in claim 2, wherein the step of controlling the operation states of the first and second low-pressure refrigerant circulation circuits according to the ambient temperature further comprises:
and if the environment temperature is lower than the preset environment temperature, controlling the first low-pressure refrigerant circulation loop to operate, and controlling the second low-pressure refrigerant circulation loop not to operate.
4. The control method according to claim 3, wherein the step of obtaining the operating parameters of the high-pressure refrigerant circulation circuit specifically comprises:
acquiring the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature of the intermediate heat exchanger;
the step of controlling the operation state of the bypass branch according to the operation parameters of the high-pressure refrigerant circulation loop specifically comprises the following steps:
and controlling the running state of the bypass branch according to the current refrigerant evaporation temperature and the maximum refrigerant evaporation temperature.
5. The control method according to claim 4, wherein the step of controlling the operation state of the bypass branch according to the current refrigerant evaporating temperature and the maximum refrigerant evaporating temperature specifically comprises:
calculating the difference value between the maximum refrigerant evaporation temperature and the current refrigerant evaporation temperature, and recording the difference value as a first difference value;
if the first difference is smaller than a first preset difference, controlling the bypass branch to operate; and/or the like and/or,
and if the first difference value is greater than or equal to the first preset difference value, controlling the bypass branch circuit not to operate.
6. The control method according to claim 3, wherein the step of obtaining the operation parameter of the high-pressure refrigerant circulation loop comprises:
acquiring the current suction pressure and the maximum suction pressure of the first compressor;
the step of controlling the operation state of the bypass branch according to the operation parameters of the high-pressure refrigerant circulation loop specifically comprises the following steps:
and controlling the running state of the bypass branch according to the current suction pressure and the maximum suction pressure.
7. The control method according to claim 6, wherein the step of controlling the operating state of the bypass branch according to the current suction pressure and the maximum suction pressure specifically comprises:
calculating the difference value between the maximum suction pressure and the current suction pressure, and recording as a second difference value;
if the second difference is smaller than a second preset difference, controlling the bypass branch to operate; and/or the like, and/or,
and if the second difference is greater than or equal to the second preset difference, controlling the bypass branch not to operate.
8. The control method according to any one of claims 5 or 7, wherein in a case where the first low-pressure refrigerant circulation circuit is operated and the bypass branch is not operated, the control method further comprises:
acquiring the temperature of a refrigerant at an outlet of the second heat exchanger;
and further controlling the running state of the bypass branch according to the temperature of the refrigerant at the outlet of the second heat exchanger.
9. The control method according to claim 8, wherein the step of further controlling the operating state of the bypass branch according to the temperature of the refrigerant at the outlet of the second heat exchanger specifically comprises:
if the temperature of the refrigerant at the outlet of the second heat exchanger is less than or equal to the preset temperature of the refrigerant, controlling the bypass branch to operate; and/or the like and/or,
and if the temperature of the refrigerant at the outlet of the second heat exchanger is greater than the preset temperature of the refrigerant, controlling the bypass branch not to operate.
10. A cascade heat pump system characterized in that it comprises a controller capable of performing the control method of any one of claims 1 to 9.
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CN114777345B (en) * 2022-04-20 2023-05-30 青岛海信日立空调系统有限公司 Refrigerating apparatus
CN117469871A (en) * 2023-12-26 2024-01-30 珠海格力电器股份有限公司 Control method and device of refrigeration system, refrigeration system and storage medium
CN117469871B (en) * 2023-12-26 2024-04-05 珠海格力电器股份有限公司 Control method and device of refrigeration system, refrigeration system and storage medium

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