CN114739063B - Heat pump unit and control method thereof - Google Patents
Heat pump unit and control method thereof Download PDFInfo
- Publication number
- CN114739063B CN114739063B CN202210451343.4A CN202210451343A CN114739063B CN 114739063 B CN114739063 B CN 114739063B CN 202210451343 A CN202210451343 A CN 202210451343A CN 114739063 B CN114739063 B CN 114739063B
- Authority
- CN
- China
- Prior art keywords
- heating device
- electric heating
- water flow
- water
- bypass branch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 260
- 238000005485 electric heating Methods 0.000 claims abstract description 77
- 238000004891 communication Methods 0.000 claims abstract description 26
- 239000003507 refrigerant Substances 0.000 claims abstract description 20
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 238000010257 thawing Methods 0.000 claims description 20
- 238000005336 cracking Methods 0.000 abstract description 6
- 239000008236 heating water Substances 0.000 abstract description 3
- 230000000694 effects Effects 0.000 abstract description 2
- 230000002265 prevention Effects 0.000 abstract description 2
- 239000007788 liquid Substances 0.000 description 5
- 238000000926 separation method Methods 0.000 description 4
- 230000008014 freezing Effects 0.000 description 2
- 238000007710 freezing Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/006—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass for preventing frost
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
- F25B47/022—Defrosting cycles hot gas defrosting
- F25B47/025—Defrosting cycles hot gas defrosting by reversing the cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
-
- Y—GENERAL 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/12—Hot water central heating systems using heat pumps
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Steam Or Hot-Water Central Heating Systems (AREA)
- Heat-Pump Type And Storage Water Heaters (AREA)
Abstract
The invention relates to the technical field of heat pumps, in particular to a heat pump unit and a control method thereof, and aims to solve the problem that an existing heat pump unit is poor in frost cracking prevention effect of a water side heat exchanger. The heat pump unit comprises a refrigerant circulation loop, a heat exchange waterway and a bypass branch, wherein the refrigerant circulation loop and the heat exchange waterway exchange heat through a second heat exchanger, an electric heating device is arranged on the heat exchange waterway, a first end of the bypass branch is connected to a water inlet side of the second heat exchanger, and a second end of the bypass branch is connected to a water outlet side of a motor heating device; according to the heat pump unit, the communication state of the bypass branch and the starting state of the electric heating device are controlled according to the obtained initial water flow, the current water flow and the obtained water outlet temperature of the heat exchange waterway, and the electric heating device can be used for heating water flowing out of the second heat exchanger before the second heat exchanger is frozen and flowing back to the second heat exchanger through the bypass branch, so that the second heat exchanger is effectively prevented from being frozen, and further the heat pump unit is effectively ensured to be kept to be in continuous operation without stopping.
Description
Technical Field
The invention relates to the technical field of heat pumps, and particularly provides a heat pump unit and a control method thereof.
Background
Along with the increasing demands of users, the development of the existing heat exchanger is approaching to refinement, and the heat exchanger has small volume and high heat exchange efficiency, so that the heat exchanger is widely applied to heat pump units. However, when the evaporation temperature of the existing heat pump unit is lower in low-temperature heating defrosting or operation refrigerating working conditions, the problem that the water side heat exchanger is easy to freeze can be solved, and when serious, the pipeline in the water side heat exchanger can be deformed or even damaged. The existing heat pump unit is used for protecting the water side heat exchanger from frost cracking by monitoring the low-pressure saturation temperature and the duration time of the low-pressure saturation temperature; specifically, when the low-pressure saturation temperature and the duration thereof reach the set values, the heat pump unit is stopped to ensure that the water side heat exchanger cannot be frozen, however, the above-mentioned mode of protecting the water side heat exchanger by shutdown can reduce the use experience of the user, and does not play a role in preventing the water side heat exchanger from freezing.
Accordingly, there is a need in the art for a new heat pump unit and a control method thereof to solve the above-mentioned technical problems.
Disclosure of Invention
The invention aims to solve the technical problems, namely the problem of poor frost cracking prevention effect of the water side heat exchanger of the existing heat pump unit.
In a first aspect, the present invention provides a control method of a heat pump unit, where the heat pump unit includes a refrigerant circulation loop, a heat exchange waterway, and a bypass branch, the refrigerant circulation loop is sequentially provided with a compressor, a first heat exchanger, a throttling member, and a second heat exchanger, a part of the heat exchange waterway is disposed in the second heat exchanger, and an electric heating device is further disposed on the heat exchange waterway, the electric heating device is disposed on a water outlet side of the second heat exchanger, water in the heat exchange waterway exchanges heat with a refrigerant in the refrigerant circulation loop through the second heat exchanger, the bypass branch is connected with the heat exchange waterway, a first end of the bypass branch is connected to a water inlet side of the second heat exchanger, a second end of the bypass branch is connected to a water outlet side of the electric heating device, and a bypass valve is disposed on the bypass branch;
the control method comprises the following steps:
before the heat pump unit starts a defrosting working condition, acquiring initial water flow of the heat exchange waterway;
under the condition that the heat pump unit is in a defrosting working condition, acquiring the current water flow and the water outlet temperature of the heat exchange waterway;
and controlling the communication state of the bypass branch and the opening state of the electric heating device according to the initial water flow, the current water flow and the water outlet temperature.
In the preferred technical solution of the above control method, the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the initial water flow, the current water flow and the outlet water temperature specifically includes:
calculating the difference value between the initial water flow and the current water flow;
and controlling the communication state of the bypass branch and the opening state of the electric heating device according to the difference value of the initial water flow and the current water flow and the water outlet temperature.
In the preferred technical solution of the above control method, the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the difference value between the initial water flow and the current water flow and the outlet water temperature includes:
if the difference value between the initial water flow and the current water flow is greater than or equal to a preset difference value; and/or if the water outlet temperature is less than or equal to a first preset water outlet temperature, controlling the bypass branch to be communicated and controlling the electric heating device to be started.
In the above preferred technical solution of the control method, the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the difference value between the initial water flow and the current water flow and the outlet water temperature further includes:
and if the difference value between the initial water flow and the current water flow is smaller than the preset difference value, and the water outlet temperature is larger than the first preset water outlet temperature and smaller than or equal to the second preset water outlet temperature, controlling the electric heating device to be started, and the bypass branch is not communicated.
In the above preferred technical solution of the control method, the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the difference value between the initial water flow and the current water flow and the outlet water temperature further includes:
if the difference value between the initial water flow and the current water flow is smaller than the preset difference value and the water outlet temperature is larger than the second preset water outlet temperature, further acquiring the duration time when the water outlet temperature is larger than the second preset water outlet temperature;
and controlling the communication state of the bypass branch and the opening state of the electric heating device according to the duration.
In a preferred embodiment of the above control method, the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the duration includes:
and if the duration is longer than or equal to the preset duration, controlling the bypass branch not to be communicated and controlling the electric heating device not to be started.
In a preferred technical solution of the above control method, the control method further includes:
under the condition that the bypass branch is communicated and the electric heating device is started, the water inlet temperature of the heat exchange waterway is further obtained;
and adjusting the running states of the electric heating device and the bypass valve according to the water inlet temperature and the preset water inlet temperature.
In a preferred technical solution of the above control method, the step of adjusting the operating states of the electric heating device and the bypass valve according to the water inlet temperature and the preset water inlet temperature includes:
and if the water inlet temperature is smaller than or equal to the preset water inlet temperature, increasing the heating power of the electric heating device and increasing the opening of the bypass valve.
In a preferred technical solution of the above control method, the step of adjusting the operating states of the electric heating device and the bypass valve according to the water inlet temperature and the preset water inlet temperature includes:
and if the water inlet temperature is higher than the preset water inlet temperature, reducing the heating power of the electric heating device and reducing the opening of the bypass valve.
In another aspect, the present invention further provides a heat pump unit, where the heat pump unit includes a controller, and the controller is capable of executing the control method described in any one of the foregoing preferred technical solutions.
Under the condition of adopting the technical scheme, the heat pump unit disclosed by the invention controls the communication state of the bypass branch and the opening state of the electric heating device according to the acquired initial water flow, the current water flow and the water outlet temperature of the heat exchange waterway, so that before the second heat exchanger is frozen, the electric heating device can be used for heating water flowing out of the second heat exchanger and flowing back to the second heat exchanger through the bypass branch, the second heat exchanger can be effectively prevented from being frozen, and further the heat pump unit is effectively ensured to be kept to be in continuous operation without stopping.
Drawings
Preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:
FIG. 1 is a schematic view of a heat pump unit according to the present invention;
FIG. 2 is a flow chart of the main steps of the control method of the present invention;
FIG. 3 is a flowchart of the specific steps of a preferred embodiment of the control method of the present invention;
reference numerals:
1. a refrigerant circulation circuit; 11. a compressor; 12. a four-way valve; 13. a first heat exchanger; 14. a throttle member; 15. a second heat exchanger; 16. a liquid storage device; 17. a gas separation device;
2. a heat exchange waterway; 21. an electric heating device;
3. a bypass branch; 31. and a bypass valve.
Detailed Description
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 merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention. Those skilled in the art can adapt it as desired to suit a particular application. For example, the heat pump unit in the invention can be a split type heat pump unit or an integral type heat pump unit, which is not limitative, and a technician can set the application object of the control method according to the actual use requirement. Such changes as to the application object do not deviate from the basic principle of the invention and fall within the protection scope of the invention.
It should be noted that, in the description of the preferred embodiment, unless explicitly stated and limited otherwise, the terms "connected" and "connected" should be interpreted broadly, for example, as mechanical connection, as electrical connection, as direct connection, as indirect connection via an intermediate medium, as internal connection between two elements, and thus should not be construed as limiting the invention. The specific meaning of the above terms in the present invention can be understood by those skilled in the art according to the specific circumstances.
Furthermore, it should be noted that in the description of the present invention, although the respective steps of the control method of the present invention are described in a specific order in the present application, these orders are not limitative, but a person skilled in the art may perform the steps in a different order without departing from the basic principle of the present invention.
Referring first to fig. 1, fig. 1 is a schematic structural diagram of a heat pump unit according to the present invention. As shown in fig. 1, the heat pump unit of the present invention includes a refrigerant circulation loop 1, a heat exchange water channel 2 and a bypass branch 3, wherein a compressor 11, a four-way valve 12, a first heat exchanger 13, a throttling member 14 and a second heat exchanger 15 are sequentially arranged on the refrigerant circulation loop 1, and the refrigerant circulation loop 1 can change the flow direction of the refrigerant through the arrangement of the four-way valve 12, so as to realize the refrigeration working condition, the heating working condition, the defrosting working condition and the like of the heat pump unit. A part of the heat exchange waterway 2 is arranged in the second heat exchanger 15, an electric heating device 21 is further arranged on the heat exchange waterway 2, the electric heating device 21 is arranged on the water outlet side of the second heat exchanger 15, water in the heat exchange waterway 2 exchanges heat with the refrigerant in the refrigerant circulation loop 1 through the second heat exchanger 15, the bypass branch 3 is connected with the heat exchange waterway 2, the first end of the bypass branch 3 is connected to the water inlet side of the second heat exchanger 15, the second end of the bypass branch 3 is connected to the water outlet side of the electric heating device 21, and the bypass branch 3 is provided with a bypass valve 31.
It should be noted that, the specific structures and specific types of the compressor 11, the four-way valve 12, the throttling member 14, the first heat exchanger 13, the second heat exchanger 15, the electric heating device 21 and the bypass valve 31 are not limited in the present invention, and the compressor 11 may be a variable frequency compressor or a fixed frequency compressor; the throttle member 14 may be a capillary tube, an electronic expansion valve, or a thermal expansion valve; the first heat exchanger 13 and the second heat exchanger 15 may be plate heat exchangers or double pipe heat exchangers; the electric heating device 21 may be a heating pipe or a heating jacket; the bypass valve 31 may be a hydraulic control valve or an electromagnetic control valve, which is not limited, and may be set by one skilled in the art according to the actual circumstances.
Preferably, the refrigerant circulation loop 1 is further provided with a liquid storage device 16 and an air separation device 17, and the liquid storage device 16 is arranged between the throttling component 14 and the second heat exchanger 15 so as to effectively ensure the flow stability of the refrigerant in the refrigerant circulation loop 1; the gas separation device 17 is provided with the gas inlet of the compressor 11 so as to effectively avoid the problem of liquid impact of the compressor 11 and effectively ensure the service life of the compressor 11. It should be noted that the specific structure of the liquid storage device 16 and the air separation device 17 is not limited in the present invention, and those skilled in the art can set the device according to the actual situation.
Further, the heat pump unit further includes a flow meter, a temperature sensor and a controller (not shown in the figure), wherein the flow meter is used for obtaining the water flow of the heat exchange waterway 2, the temperature sensor is used for obtaining the water inlet temperature and the water outlet temperature of the heat exchange waterway 2, the controller is capable of obtaining the water inlet temperature and the water outlet temperature of the heat exchange waterway 2 detected by the temperature sensor and the water flow of the heat exchange waterway 2 obtained by the flow meter, and the controller is also capable of controlling the communication state of the bypass branch 3 and the opening and closing state of the electric heating device 21, etc., which are not limitative. It should be noted that, the present invention does not limit the specific model, the number of the setting and the setting positions of the flowmeter and the temperature sensor, so long as the water flow, the water inlet temperature and the water outlet temperature of the heat exchange waterway 2 can be obtained, and the present invention can be set by a person skilled in the art according to the actual situation. In addition, it will 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 an original controller of the heat pump unit or a controller separately provided for executing the control method of the present invention, and those skilled in the art may set the structure and model of the controller according to actual use requirements.
Referring next to fig. 2, fig. 2 is a flow chart of main steps of the control method of the present invention. As shown in fig. 2, based on the heat pump unit described in the above embodiment, the control method of the present invention mainly includes the following steps:
s1: before a defrosting working condition of a heat pump unit is started, acquiring initial water flow of a heat exchange waterway;
s2: under the condition that the heat pump unit is in a defrosting working condition, acquiring the current water flow and the water outlet temperature of a heat exchange waterway;
s3: and controlling the communication state of the bypass branch and the opening state of the electric heating device according to the initial water flow, the current water flow and the water outlet temperature.
First, in step S1, before the heat pump unit starts the defrosting operation, the controller obtains an initial water flow of the heat exchange waterway 2. Next, in step S2, under the condition that the heat pump unit is in the defrosting condition, the controller obtains the current water flow and the outlet water temperature of the heat exchange waterway 2.
It should be noted that, the invention does not limit the specific obtaining mode and the specific obtaining time of the initial water flow, the current water flow and the outlet water temperature of the heat exchange waterway 2, the controller can obtain the current water flow and the outlet water temperature when the heat pump unit starts to operate in a defrosting working condition, and the controller can also obtain the current water flow and the outlet water temperature after the heat pump unit operates in the defrosting working condition for a period of time, which is not limited; preferably, the current water flow and the outlet water temperature are obtained when the heat pump unit starts to operate under the defrosting working condition, so that the problems of icing and frost cracking of the second heat exchanger 15 can be effectively placed in time.
In addition, the acquisition modes of the initial water flow and the current water flow can be monitored through the flow rate of water, and also can be monitored through the water inlet time; as a preferable setting mode, the invention monitors the flow rate of water through the flowmeter, further obtains the water flow rate in the heat exchange waterway 2, and can ensure the accuracy of the obtained data by determining the initial water flow rate and the current water flow rate through the flow rate of water.
Further, in step S3, the controller controls the communication state of the bypass branch 3 and the on state of the electric heating device 21 according to the initial water flow, the current water flow, and the outlet water temperature.
It should be noted that the present invention does not limit the above specific control manner, for example, the controller may compare the initial water flow with the current water flow, and the outlet water temperature with the preset outlet water temperature, and jointly control the communication state of the bypass branch 3 and the on state of the electric heating device 21 according to the comparison result; of course, this is not limitative, and a person skilled in the art can set the bypass according to the actual use requirements, as long as the communication state of the bypass branch 3 and the on state of the electric heating device 21 are controlled according to the initial water flow, the current water flow and the outlet water temperature, which falls within the protection scope of the present invention.
Referring next to fig. 3, fig. 3 is a flowchart showing the specific steps of a preferred embodiment of the control method of the present invention. As shown in fig. 3, based on the heat pump unit described in the above embodiment, the control method of the preferred embodiment of the present invention includes the steps of:
s101: before a defrosting working condition of a heat pump unit is started, acquiring initial water flow of a heat exchange waterway;
s102: under the condition that the heat pump unit is in a defrosting working condition, acquiring the current water flow and the water outlet temperature of a heat exchange waterway;
s103: calculating the difference value between the initial water flow and the current water flow;
s104: if the difference value between the initial water flow and the current water flow is larger than or equal to a preset difference value; and/or if the outlet water temperature is less than or equal to the first preset outlet water temperature, controlling the bypass branch to be communicated and controlling the electric heating device to be started;
s105: if the difference value between the initial water flow and the current water flow is smaller than the preset difference value, and the water outlet temperature is larger than the first preset water outlet temperature and smaller than or equal to the second preset water outlet temperature, controlling the electric heating device to be started, and enabling the bypass branch not to be communicated;
s106: if the difference value of the initial water flow and the current water flow is smaller than the preset difference value and the water outlet temperature is larger than the second preset water outlet temperature, further acquiring the duration time when the water outlet temperature is larger than the second preset water outlet temperature;
s107: if the duration is longer than or equal to the preset duration, the bypass branch is controlled not to be communicated and the electric heating device is controlled not to be started;
s108: further acquiring the water inlet temperature of the heat exchange waterway;
s109: if the water inlet temperature is less than or equal to the preset water inlet temperature, increasing the heating power of the electric heating device and increasing the opening of the bypass valve;
s110: if the water inlet temperature is higher than the preset water inlet temperature, the heating power of the electric heating device is reduced, and the opening of the bypass valve is reduced.
First, in step S101, before the heat pump unit starts the defrosting operation, the controller obtains an initial water flow of the heat exchange waterway 2. Next, in step S102, under the condition that the heat pump unit is in the defrosting condition, the controller obtains the current water flow and the outlet water temperature of the heat exchange waterway 2.
It should be noted that, the invention does not limit the specific obtaining mode and the specific obtaining time of the initial water flow, the current water flow and the outlet water temperature of the heat exchange waterway 2, the controller can obtain the current water flow and the outlet water temperature when the heat pump unit starts to operate in a defrosting working condition, and the controller can also obtain the current water flow and the outlet water temperature after the heat pump unit operates in the defrosting working condition for a period of time, which is not limited; preferably, the current water flow and the outlet water temperature are obtained when the heat pump unit starts to operate under the defrosting working condition, so that the problems of icing and frost cracking of the second heat exchanger 15 can be effectively placed in time.
In addition, the acquisition modes of the initial water flow and the current water flow can be monitored through the flow rate of water, and also can be monitored through the water inlet time; in the preferred embodiment, the controller monitors the flow rate of water through the flowmeter, so as to obtain the water flow rate in the heat exchange waterway 2, and the accuracy of the obtained data can be ensured by determining the initial water flow rate and the current water flow rate through the flow rate of water.
Further, the controller controls the communication state of the bypass branch 3 and the on state of the electric heating device 21 according to the initial water flow, the current water flow and the water outlet temperature, so that before the second heat exchanger 15 freezes, the electric heating device 21 is used for heating water flowing out of the second heat exchanger 15 and flows back to the second heat exchanger 15 through the bypass branch 3, the second heat exchanger 15 can be effectively guaranteed not to freeze, and further the heat pump unit is effectively guaranteed not to stop and continuously run.
Specifically, in step S103, the controller calculates a difference between the initial water flow rate and the current water flow rate. Then, the communication state of the bypass branch 3 and the on state of the electric heating device 21 are controlled according to the difference between the initial water flow and the current water flow and the water outlet temperature. It should be noted that, the present invention does not limit the specific control manner, and those skilled in the art can set the control manner according to the actual situation.
As a preferred embodiment, specifically, in step S104, as long as any one of the two conditions that the difference between the initial water flow and the current water flow is greater than or equal to a preset difference and the outlet water temperature is less than or equal to a first preset outlet water temperature is satisfied, which indicates that there is a risk of freezing and cracking of the current second heat exchanger 15, the controller controls the bypass branch 3 to be connected and controls the electric heating device 21 to be turned on, and at this time, the bypass valve 31 is in an open state. Based on the control mode, the water flowing out of the second heat exchanger 15 is heated in the electric heating device 21 and then returns to the second heat exchanger 15 through the bypass branch 3, so that the temperature of the second heat exchanger 15 is effectively ensured not to be too low, namely, the second heat exchanger 15 is effectively ensured not to be frozen, and further, the heat pump unit is effectively ensured not to stop and continuously run.
Further, in step S105, if the difference between the initial water flow and the current water flow is smaller than the preset difference, and the outlet water temperature is greater than the first preset outlet water temperature and smaller than or equal to the second preset outlet water temperature, which indicates that the temperature of the second heat exchanger 15 is lower at this time, when the temperature is not lower, the controller controls the electric heating device 21 to be turned on, and the bypass branch 3 is not communicated, so that the second heat exchanger 15 is not frozen, and normal operation of the heat exchange waterway 2 is effectively ensured.
Further preferably, in step S106, if the difference between the initial water flow and the current water flow is smaller than the preset difference and the outlet water temperature is greater than the second preset outlet water temperature, the controller further obtains a duration for which the outlet water temperature is greater than the second preset outlet water temperature, and controls the communication state of the bypass branch 3 and the on state of the electric heating device 21 according to the duration. Based on the control mode, the heat pump unit can further effectively ensure that the second heat exchanger 15 cannot be frozen.
Specifically, in step S107, if the duration is greater than or equal to the preset duration, which indicates that the current second heat exchanger 15 does not have a risk of icing, the controller controls the bypass branch 3 not to be connected and controls the electric heating device 21 not to be turned on, so as to effectively reduce the operation energy consumption of the heat pump unit. Otherwise, if the duration is less than the preset duration, the controller controls the current states of the bypass 3 and the electric heating device 21 until the duration is greater than or equal to the preset duration, so as to further effectively ensure that the second heat exchanger 15 does not freeze.
In addition, in step S108, in the case where the bypass 3 is connected and the electric heating device 21 is turned on, the controller further acquires the water inflow temperature of the heat exchange waterway 2 through the temperature sensor. It should be noted that, the specific acquisition mode of the water inlet temperature by the controller is not limited, the controller can acquire the water inlet temperature in real time or at intervals, which is not limited, and the controller can be set by a person skilled in the art according to practical situations. Preferably, the controller acquires the inlet water temperature in real time, so as to further effectively ensure that the second heat exchanger 15 does not freeze.
Next, the controller adjusts the operation states of the electric heating device 21 and the bypass valve 31 according to the water inlet temperature and the preset water inlet temperature. It should be noted that the present invention does not limit the above specific control manner, and the controller may adjust the operation states of the electric heating device 21 and the bypass valve 31 according to the difference result or the comparison result between the inlet water temperature and the preset inlet water temperature; of course, this is not limiting and can be set by one skilled in the art.
As a preferred embodiment, in step S109, if the inlet water temperature is less than or equal to the preset inlet water temperature, the controller controls the heating power of the electric heating device 21 to be increased and controls the opening of the bypass valve 31 to be increased so as to increase the amount of water flowing back into the second heat exchanger 15 from the electric heating device 21 through the bypass branch 3, thereby further effectively ensuring that the second heat exchanger 15 does not freeze.
Further, in step S110, if the inlet water temperature is greater than the preset inlet water temperature, the controller controls the heating power of the electric heating device 21 to be reduced and controls the opening of the bypass valve 31 to be reduced, so as to reduce the amount of water flowing back to the second heat exchanger 15 from the electric heating device 21 through the bypass branch 3, so as to effectively ensure the normal water supply requirement of the heat exchange waterway 2.
It should be noted that, the present invention does not limit the specific setting values of the preset difference value, the first preset outlet water temperature, the second preset outlet water temperature, the preset duration time and the preset inlet water temperature, and those skilled in the art can set the setting values according to actual situations.
Thus far, the technical solution of the present invention has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will fall within the scope of the present invention.
Claims (8)
1. The control method of the heat pump unit is characterized in that the heat pump unit comprises a refrigerant circulation loop, a heat exchange waterway and a bypass branch, wherein a compressor, a first heat exchanger, a throttling component and a second heat exchanger are sequentially arranged on the refrigerant circulation loop, a part of the heat exchange waterway is arranged in the second heat exchanger, an electric heating device is further arranged on the heat exchange waterway, the electric heating device is arranged on the water outlet side of the second heat exchanger, water in the heat exchange waterway exchanges heat with refrigerant in the refrigerant circulation loop through the second heat exchanger, the bypass branch is connected with the heat exchange waterway, the first end of the bypass branch is connected to the water inlet side of the second heat exchanger, the second end of the bypass branch is connected to the water outlet side of the electric heating device, and a bypass valve is arranged on the bypass branch;
the control method comprises the following steps:
before the heat pump unit starts a defrosting working condition, acquiring initial water flow of the heat exchange waterway;
under the condition that the heat pump unit is in a defrosting working condition, acquiring the current water flow and the water outlet temperature of the heat exchange waterway;
controlling the communication state of the bypass branch and the opening state of the electric heating device according to the initial water flow, the current water flow and the water outlet temperature;
the step of controlling the communication state of the bypass branch and the opening state of the electric heating device according to the initial water flow, the current water flow and the water outlet temperature specifically comprises the following steps:
calculating the difference value between the initial water flow and the current water flow;
controlling the communication state of the bypass branch and the opening state of the electric heating device according to the difference value of the initial water flow and the current water flow and the water outlet temperature;
the step of controlling the communication state of the bypass branch and the opening state of the electric heating device according to the difference value between the initial water flow and the current water flow and the water outlet temperature comprises the following steps:
if the difference value between the initial water flow and the current water flow is greater than or equal to a preset difference value; and/or if the water outlet temperature is less than or equal to a first preset water outlet temperature, controlling the bypass branch to be communicated and controlling the electric heating device to be started.
2. The control method according to claim 1, wherein the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the difference between the initial water flow and the current water flow and the outlet water temperature further comprises:
and if the difference value between the initial water flow and the current water flow is smaller than the preset difference value, and the water outlet temperature is larger than the first preset water outlet temperature and smaller than or equal to the second preset water outlet temperature, controlling the electric heating device to be started, and the bypass branch is not communicated.
3. The control method according to claim 2, wherein the step of controlling the communication state of the bypass branch and the on state of the electric heating device according to the difference between the initial water flow and the current water flow and the outlet water temperature further comprises:
if the difference value between the initial water flow and the current water flow is smaller than the preset difference value and the water outlet temperature is larger than the second preset water outlet temperature, further acquiring the duration time when the water outlet temperature is larger than the second preset water outlet temperature;
and controlling the communication state of the bypass branch and the opening state of the electric heating device according to the duration.
4. A control method according to claim 3, wherein the step of "controlling the communication state of the bypass branch and the on state of the electric heating device according to the duration" includes:
and if the duration is longer than or equal to the preset duration, controlling the bypass branch not to be communicated and controlling the electric heating device not to be started.
5. The control method according to any one of claims 1 to 4, characterized in that the control method further comprises:
under the condition that the bypass branch is communicated and the electric heating device is started, the water inlet temperature of the heat exchange waterway is further obtained;
and adjusting the running states of the electric heating device and the bypass valve according to the water inlet temperature and the preset water inlet temperature.
6. The control method according to claim 5, wherein the step of adjusting the operating states of the electric heating device and the bypass valve according to the water intake temperature and a preset water intake temperature includes:
and if the water inlet temperature is smaller than or equal to the preset water inlet temperature, increasing the heating power of the electric heating device and increasing the opening of the bypass valve.
7. The control method according to claim 5, wherein the step of adjusting the operating states of the electric heating device and the bypass valve according to the water intake temperature and a preset water intake temperature includes:
and if the water inlet temperature is higher than the preset water inlet temperature, reducing the heating power of the electric heating device and reducing the opening of the bypass valve.
8. A heat pump unit, characterized in that it comprises a controller capable of executing the control method according to any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210451343.4A CN114739063B (en) | 2022-04-26 | 2022-04-26 | Heat pump unit and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210451343.4A CN114739063B (en) | 2022-04-26 | 2022-04-26 | Heat pump unit and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114739063A CN114739063A (en) | 2022-07-12 |
| CN114739063B true CN114739063B (en) | 2024-02-23 |
Family
ID=82283014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210451343.4A Active CN114739063B (en) | 2022-04-26 | 2022-04-26 | Heat pump unit and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114739063B (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010109689A1 (en) * | 2009-03-27 | 2010-09-30 | 日立アプライアンス株式会社 | Heat pump type hot water supply device |
| JP2012007800A (en) * | 2010-06-24 | 2012-01-12 | Mitsubishi Heavy Ind Ltd | Heat pump type hot-water supply and air-conditioning system |
| JP2015124911A (en) * | 2013-12-25 | 2015-07-06 | ダイキン工業株式会社 | Hot water supply air-conditioning system |
| CN104813121A (en) * | 2012-12-11 | 2015-07-29 | 三菱电机株式会社 | Air conditioner hot water supply composite system |
| CN105650872A (en) * | 2014-11-12 | 2016-06-08 | 青岛海尔智能技术研发有限公司 | Water heater |
| CN205481928U (en) * | 2015-12-30 | 2016-08-17 | 重庆美的通用制冷设备有限公司 | Water side heat exchanger and have its cooling water set, heat pump set |
| CN107726633A (en) * | 2017-10-12 | 2018-02-23 | 广东美的暖通设备有限公司 | Heat pump water-heating machine and its anti-freeze control method and device |
| CN109974296A (en) * | 2017-12-28 | 2019-07-05 | 杭州先途电子有限公司 | A kind of air energy water heater and its Defrost method |
| CN111536711A (en) * | 2020-04-08 | 2020-08-14 | 珠海格力电器股份有限公司 | Heat pump hot water unit and control method for water flow abnormity thereof |
| CN113357843A (en) * | 2020-03-04 | 2021-09-07 | 青岛海尔空调电子有限公司 | Air conditioning system and defrosting control method thereof |
| WO2021227365A1 (en) * | 2020-05-09 | 2021-11-18 | 艾默生环境优化技术(苏州)有限公司 | Anti-freezing protection method, anti-freezing protection system, and heat pump unit of water system |
-
2022
- 2022-04-26 CN CN202210451343.4A patent/CN114739063B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010109689A1 (en) * | 2009-03-27 | 2010-09-30 | 日立アプライアンス株式会社 | Heat pump type hot water supply device |
| JP2012007800A (en) * | 2010-06-24 | 2012-01-12 | Mitsubishi Heavy Ind Ltd | Heat pump type hot-water supply and air-conditioning system |
| CN104813121A (en) * | 2012-12-11 | 2015-07-29 | 三菱电机株式会社 | Air conditioner hot water supply composite system |
| JP2015124911A (en) * | 2013-12-25 | 2015-07-06 | ダイキン工業株式会社 | Hot water supply air-conditioning system |
| CN105650872A (en) * | 2014-11-12 | 2016-06-08 | 青岛海尔智能技术研发有限公司 | Water heater |
| CN205481928U (en) * | 2015-12-30 | 2016-08-17 | 重庆美的通用制冷设备有限公司 | Water side heat exchanger and have its cooling water set, heat pump set |
| CN107726633A (en) * | 2017-10-12 | 2018-02-23 | 广东美的暖通设备有限公司 | Heat pump water-heating machine and its anti-freeze control method and device |
| CN109974296A (en) * | 2017-12-28 | 2019-07-05 | 杭州先途电子有限公司 | A kind of air energy water heater and its Defrost method |
| CN113357843A (en) * | 2020-03-04 | 2021-09-07 | 青岛海尔空调电子有限公司 | Air conditioning system and defrosting control method thereof |
| CN111536711A (en) * | 2020-04-08 | 2020-08-14 | 珠海格力电器股份有限公司 | Heat pump hot water unit and control method for water flow abnormity thereof |
| WO2021227365A1 (en) * | 2020-05-09 | 2021-11-18 | 艾默生环境优化技术(苏州)有限公司 | Anti-freezing protection method, anti-freezing protection system, and heat pump unit of water system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114739063A (en) | 2022-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109282545B (en) | Air-supplying and enthalpy-increasing control method of low-temperature direct-current variable-frequency heat pump system | |
| WO2023005246A1 (en) | Control method for air source heat pump unit | |
| CN103383157B (en) | Heat pump type air conditioning system and control method thereof | |
| CN106322768B (en) | Water heater and control method thereof | |
| CN114484953B (en) | Heat pump unit and control method thereof | |
| CN113137677B (en) | Heat recovery air conditioning system and control method thereof | |
| CN101473176B (en) | Flow rate control system in refrigeration circuits, method for controlling a refrigeration system and a refrigeration system | |
| CN110736276B (en) | Control method of natural cooling refrigeration system | |
| CN114992889A (en) | Cascade heat pump system and control method thereof | |
| CN114739063B (en) | Heat pump unit and control method thereof | |
| CN106931546B (en) | Heat pump enthalpy-spraying system, control method thereof and air conditioner | |
| CN112303827A (en) | Control method of combined air-conditioning system | |
| JP2014077560A (en) | Air conditioner | |
| CN112747391A (en) | Air conditioning unit and compressor cooling control method thereof | |
| CN117006720A (en) | Cascade heat pump system and control method thereof | |
| CN115540374A (en) | Refrigerating unit | |
| CN110411066B (en) | Oil cooling system of water chilling unit and control method thereof | |
| CN110513914A (en) | A kind of heat pump heat distribution system and its control method | |
| JP2004245560A (en) | Heat source system, control method of heat source system, heat source and control method of heat source | |
| CN114992778B (en) | Anti-freezing control method of air conditioning unit | |
| CN115307324B (en) | Cascade heat pump system and defrosting control method thereof | |
| CN219776097U (en) | Energy-saving water-cooling refrigerating unit | |
| CN220287880U (en) | Energy-saving control system of refrigeration house evaporation system | |
| CN109764577B (en) | Low-temperature heat pump system and control method of reversing valve thereof | |
| CN115164432B (en) | Heat pump system and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |