CN114739047A - Heat pump water heater and control method for exhaust temperature of compressor thereof - Google Patents
Heat pump water heater and control method for exhaust temperature of compressor thereof Download PDFInfo
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- CN114739047A CN114739047A CN202210444794.5A CN202210444794A CN114739047A CN 114739047 A CN114739047 A CN 114739047A CN 202210444794 A CN202210444794 A CN 202210444794A CN 114739047 A CN114739047 A CN 114739047A
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- 238000000034 method Methods 0.000 title claims abstract description 37
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 239000007788 liquid Substances 0.000 claims abstract description 99
- 238000005507 spraying Methods 0.000 claims abstract description 51
- 238000002347 injection Methods 0.000 claims abstract description 25
- 239000007924 injection Substances 0.000 claims abstract description 25
- 239000003507 refrigerant Substances 0.000 claims abstract description 19
- 230000001174 ascending effect Effects 0.000 claims description 8
- 230000008569 process Effects 0.000 claims description 8
- 230000000630 rising effect Effects 0.000 claims description 6
- 230000007613 environmental effect Effects 0.000 claims description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- 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
- F25B29/00—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously
- F25B29/003—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously of the compression type system
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H4/00—Fluid heaters characterised by the use of heat pumps
- F24H4/02—Water heaters
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- 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
- F25B13/00—Compression machines, plants or systems, with reversible 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
- F25B41/00—Fluid-circulation arrangements
- F25B41/20—Disposition of valves, e.g. of on-off valves or flow control valves
-
- 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
-
- 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
- F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
- F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
- F25B2313/02741—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
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- 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
- F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
- F25B2400/19—Pumping down refrigerant from one part of the cycle to another part of the cycle, e.g. when the cycle is changed from cooling to heating, or before a defrost cycle is started
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- 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
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
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- 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]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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- Engineering & Computer Science (AREA)
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- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention discloses a heat pump water heater and a control method of the exhaust temperature of a compressor thereof, which comprises that a refrigerant on a main path sequentially passes through the compressor, a four-way valve, a sleeve heat exchanger, a liquid storage device and a fin evaporator, then enters a gas-liquid separator through the four-way valve again and then returns to the compressor, and a main path electronic expansion valve for controlling the flow of the refrigerant on the main path is arranged on a pipeline connecting the liquid storage device and the fin evaporator; the auxiliary road is also included, one end of the auxiliary road is communicated with the liquid storage device and one end of the main road electronic expansion valve, the other end of the auxiliary road is communicated with the air inlet of the compressor, and the auxiliary road is provided with a liquid injection electronic expansion valve and a liquid injection electromagnetic valve; when the compressor is started under the conditions of low ambient temperature and high water temperature in the unit, the flow of the refrigerant in the unit is periodically adjusted by controlling the main-circuit electronic expansion valve and the liquid-spraying electronic expansion valve, so that the problems that the unit cannot be started and is abnormally started due to overhigh exhaust temperature when the compressor is started are solved.
Description
Technical Field
The invention relates to the field of heat exchange, in particular to a heat pump water heater and a control method of the exhaust temperature of a compressor thereof.
Background
At present, the application environment range of most low-temperature heat pump water heaters in the market is-25-45 ℃ and even lower, the water heaters are mainly used for providing hot water with a certain temperature for users, the water temperature is required to be 50-55 ℃, particularly, in a low-temperature environment, the air suction specific volume of a compressor is increased when the water temperature is higher than 50 ℃, the air suction volume is reduced, the mass flow flowing through the compressor is reduced, the cooling effect of a motor enameled wire in the compressor is poor, particularly, the compression ratio of the compressor is increased along with the increase of the water temperature under severe working conditions, the exhaust temperature is increased along with the increase of the air temperature, the exhaust temperature is an important parameter for measuring the normal operation of the compressor, the exhaust is too high, lubricating oil between moving parts can be carbonized, the parts can also be slightly deformed, the moving parts are easily abraded, and the operation of the compressor is finally influenced. At present, in order to deal with the area with cold northern climate, a part of known compressor manufacturers provide a compressor with a liquid spraying cooling function, liquid refrigerant is introduced from an outlet pipe of a condenser and then sprayed into a compressor scroll to achieve the purpose of reducing the exhaust temperature of a motor coil and a compressor in a compressor cavity, but in a low-temperature environment of the compressor, when the water temperature is higher than 50 ℃ and is started within 2min, the exhaust air can rise to a high value due to sharp reduction of the air suction amount, the value can exceed an exhaust protection value set by the unit, and once the unit is protected, the unit cannot operate.
Disclosure of Invention
In order to solve the problems that the compressor is abnormally started or even cannot be started due to overhigh exhaust temperature of the compressor under the conditions of low environmental temperature and high water temperature in the unit in the prior art, the invention aims to provide the heat pump water heater and the control method of the exhaust temperature of the compressor thereof.
In order to achieve the purpose, the invention adopts the following technical scheme: a compressor exhaust temperature control method comprises a main path for heat exchange and an auxiliary path for reducing exhaust temperature, wherein a refrigerant on the main path sequentially passes through a compressor, a four-way valve, a double-pipe heat exchanger, a liquid storage device and a fin evaporator, then enters a gas-liquid separator through the four-way valve again and then returns to the compressor, and a main path electronic expansion valve for controlling the flow of the refrigerant of the main path is arranged on a pipeline connecting the liquid storage device and the fin evaporator; one end of the auxiliary road is communicated with one end of the liquid storage device and one end of the main road electronic expansion valve, the other end of the auxiliary road is communicated with an air inlet of the compressor, the auxiliary road is provided with a liquid spraying electronic expansion valve and a liquid spraying electromagnetic valve, and a refrigerant in the auxiliary road enters the air inlet of the compressor after passing through the liquid spraying electromagnetic valve and the liquid spraying electronic expansion valve in sequence; when the compressor is started under the conditions of low ambient temperature and high water temperature in the unit, the control method for starting the compressor comprises the following steps:
1) main-path control: determining the initial opening degree of a main-circuit electronic expansion valve according to the outdoor environment temperature and the water temperature in the unit, immediately reducing the N opening degree of the main-circuit electronic expansion valve after the compressor is started for 2min, and then reducing the N opening degree of the main-circuit electronic expansion valve every other time period T until the opening degree of the main-circuit electronic expansion valve is not larger than the opening degree of the main-circuit electronic expansion valve set by a system when the compressor is started at the current environment temperature;
2) auxiliary road control: when the exhaust temperature of the compressor is higher than the preset valve opening temperature of the system, the auxiliary electromagnetic valve is opened, the expansion valve is opened, and the opening of the liquid spraying electronic expansion valve is controlled according to the exhaust temperature interval of the compressor in the subsequent process;
in the process of adjusting the electronic expansion valve of the liquid spray,
2.1), when the valve opening temperature is less than the exhaust temperature Td of the current compressor and less than or equal to the valve opening temperature and the temperature control value is satisfied, if the exhaust temperature of the compressor is in an ascending state, the opening degree of the liquid injection electronic expansion valve is adjusted to be as follows: (current discharge temperature Td-valve opening temperature of compressor) x calculation coefficient; if the exhaust temperature of the compressor is in a descending state or unchanged, the opening of the liquid spraying electronic expansion valve is unchanged;
2.2) when the exhaust temperature Td of the compressor is greater than the valve opening temperature and the temperature control value is satisfied, if the exhaust temperature of the compressor is in an ascending state or unchanged, the opening degree of the liquid spraying electronic expansion valve is adjusted to be as follows: (current compressor discharge temperature Td-valve opening temperature) x calculation coefficient; if the exhaust temperature of the compressor is in a descending state, the opening degree of the liquid spraying electronic expansion valve is unchanged;
2.3), when the valve opening temperature-temperature control value is less than the current exhaust temperature Td of the compressor and less than or equal to the valve opening temperature, if the exhaust temperature of the compressor is in a descending state, reducing the opening of the liquid spraying electronic expansion valve, and adjusting the opening of the liquid spraying electronic expansion valve as follows: (valve opening temperature-current compressor discharge temperature Td)/2 × calculation coefficient; if the exhaust temperature of the compressor is not changed, the opening degree of the liquid spraying electronic expansion valve is not changed; if the exhaust temperature of the compressor is in a rising state, the opening rating of the liquid spraying electronic expansion valve is increased;
2.4) when the exhaust temperature Td of the compressor is less than or equal to the valve opening temperature and the temperature control value is established, if the exhaust temperature of the compressor is in a descending state, reducing the opening degree of the liquid spraying electronic expansion valve, and adjusting the opening degree of the liquid spraying electronic expansion valve to be as follows: (valve opening temperature-current compressor discharge temperature Td)/2 × calculation coefficient; if the exhaust temperature of the compressor is in an ascending state or is unchanged, the opening degree of the liquid spraying electronic expansion valve is not changed;
2.5) if the exhaust temperature Td of the current compressor is less than the valve closing temperature, closing the liquid spraying electromagnetic valve and the liquid spraying electronic expansion valve.
Preferably, in the step 1), when the ambient temperature is more than or equal to-15 ℃ and less than 0 ℃ and the water temperature in the unit is more than or equal to 47 ℃, the initial pulse of the main circuit electronic expansion valve is 300 degrees of opening when the unit is started, and the opening degree of the main circuit electronic expansion valve 6 is periodically reduced after the unit runs for 2 min.
Preferably, in step 1), when the ambient temperature is less than-15 ℃ and the water temperature in the unit is more than or equal to 42 ℃, the initial pulse of the main circuit electronic expansion valve is 400 degrees when the unit is started, and the opening degree of the main circuit electronic expansion valve is periodically reduced after the unit is operated for 2 min.
Preferably, in step 1), the initial opening degree of the main circuit electronic expansion valve is smaller as the ambient temperature to which the compressor is exposed is lower.
Preferably, the maximum opening of the liquid jet electronic expansion valve in automatic adjustment is 480, and the minimum opening of the liquid jet electronic expansion valve in automatic adjustment is 60.
Preferably, the interval period of liquid injection electronic expansion valve adjustment is 2 s.
Preferably, in the step 2), the value of the calculation coefficient is determined according to the temperature difference of the discharge temperature of the compressor in an interval period, and the larger the temperature difference is, the larger the value of the calculation value is.
Preferably, in the step 2.3), if the discharge temperature of the compressor is in an increased state, the liquid jet electronic expansion valve is adjusted by increasing the opening by 3.
Preferably, the process of main road control in step 1) and the process of auxiliary road control in step 2) can be independently operated and controlled.
The heat pump water heater applying the compressor exhaust temperature control method is characterized in that: comprising a main path for heat exchange and a secondary path for reducing the temperature of the exhaust gas.
The technical scheme of the invention has the beneficial effects that: 1. the flow of the refrigerant for heat exchange in the unit is periodically adjusted by controlling the main-circuit electronic expansion valve, and meanwhile, the flow of the refrigerant which is sprayed out from the auxiliary circuit and used for cooling the compressor is periodically adjusted by the exhaust temperature of the compressor, so that the problems that the unit cannot be started and is abnormally started due to overhigh exhaust temperature when the compressor is started are avoided, and the running stability of the unit and the adaptability of the unit to the environment are improved; 2. the ambient temperature and the temperature difference within each time interval are introduced to control the opening degree of the electronic expansion valve, so that the electronic expansion valve is adjusted more flexibly, and the exhaust temperature of the compressor is reduced.
Drawings
FIG. 1 is a schematic structural diagram of a heat pump water heater;
FIG. 2 is a line graph of the discharge temperature of two compressors under the conditions of low ambient temperature and high water temperature in the unit;
fig. 3 is a line diagram of the exhaust temperatures of two compressors after applying the compressor exhaust temperature control method under the conditions of low ambient temperature and high water temperature in the unit.
Reference numerals: 1. a compressor; 2. an exhaust gas sensor; 3. a four-way valve; 4. a double pipe heat exchanger; 5. a bidirectional reservoir; 6. an electronic expansion valve; 7. a finned evaporator; 8. a fan assembly; 9. an inspiration sensor; 10. a gas-liquid separator; 11. a liquid spraying electromagnetic valve; 12. a liquid-spraying electronic expansion valve; A. a discharge temperature profile for the first compressor; B. discharge temperature profile of the second compressor.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the present invention.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "a plurality" means two or more unless explicitly defined otherwise.
In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
Examples
A control method of the exhaust temperature of a compressor is disclosed, as shown in figure 1, and comprises a main path for heat exchange and an auxiliary path for reducing the exhaust temperature, wherein a refrigerant on the main path sequentially passes through the compressor 1, a four-way valve 3, a double-pipe heat exchanger 4, a liquid storage device 5 and a fin evaporator 7, then enters a gas-liquid separator 10 through the four-way valve 3 again and then returns to the compressor 1, and a main path electronic expansion valve 6 for controlling the flow rate of the refrigerant of the main path is arranged on a pipeline connecting the liquid storage device 5 and the fin evaporator 7; one end of the auxiliary road is communicated with one end of the liquid storage device 5 and one end of the main road electronic expansion valve 6, the other end of the auxiliary road is communicated with the air inlet of the compressor 1, the auxiliary road is provided with a liquid injection electronic expansion valve 12 and a liquid injection electromagnetic valve 11, and a refrigerant in the auxiliary road enters the air inlet of the compressor 1 after passing through the liquid injection electromagnetic valve 11 and the liquid injection electronic expansion valve 12 in sequence; when the compressor 1 is started under the conditions of low ambient temperature and high water temperature in the unit, the control method for starting the compressor 1 comprises the following steps:
1) main path control: determining the initial opening degree of the main electronic expansion valve 6 according to the outdoor environment temperature and the water temperature in the unit, immediately reducing the N opening degree of the main electronic expansion valve 6 after the compressor 1 is started for 2min, and then reducing the N opening degree of the main electronic expansion valve 6 at intervals of a time period T until the opening degree of the main electronic expansion valve 6 is not greater than the opening degree of the main electronic expansion valve 6 set by a system when the compressor 1 is started at the current environment temperature;
2) auxiliary road control: when the exhaust temperature of the compressor 1 is higher than the preset valve opening temperature of the system, the auxiliary electromagnetic valve is opened, the expansion valve is opened, and in the subsequent process, the opening degree of the liquid spraying electronic expansion valve 12 is controlled according to the exhaust temperature interval of the compressor 1; during the regulation of the liquid spray electronic expansion valve 12,
2.1). when the valve opening temperature < the exhaust temperature Td of the compressor 1 is less than or equal to the valve opening temperature and the temperature control value is satisfied, and if the exhaust temperature of the compressor 1 is in an ascending state, the opening degree of the liquid injection electronic expansion valve 12 is adjusted to be as follows: (current discharge temperature Td of the compressor 1-valve opening temperature) x calculation coefficient; if the exhaust temperature of the compressor 1 is in a descending state or unchanged, the opening degree of the liquid spraying electronic expansion valve 12 is unchanged;
2.2) when the discharge temperature Td of the compressor 1 is greater than the valve opening temperature and the temperature control value is satisfied, if the discharge temperature of the compressor 1 is in the rising state or unchanged, the opening degree of the liquid injection electronic expansion valve 12 is adjusted to be: (current discharge temperature Td of the compressor 1-valve opening temperature) x calculation coefficient; if the exhaust temperature of the compressor 1 is in a descending state, the opening degree of the liquid spraying electronic expansion valve 12 is unchanged;
2.3), when the valve opening temperature-temperature control value is less than the current exhaust temperature Td of the compressor 1 and less than or equal to the valve opening temperature, if the exhaust temperature of the compressor 1 is in a descending state, the opening degree of the liquid spraying electronic expansion valve 12 is reduced, and the opening degree of the liquid spraying electronic expansion valve 12 is adjusted to be as follows: (valve opening temperature-current discharge temperature Td of the compressor 1)/2 × calculation coefficient; if the exhaust temperature of the compressor 1 is not changed, the opening degree of the liquid spraying electronic expansion valve 12 is not changed; if the exhaust temperature of the compressor 1 is in a rising state, the aperture of the liquid injection electronic expansion valve 12 is increased in rating;
2.4) when the exhaust temperature Td of the compressor 1 is less than or equal to the valve opening temperature-the temperature control value is established, if the exhaust temperature of the compressor 1 is in a descending state, the opening degree of the liquid injection electronic expansion valve 12 is reduced, and the opening degree of the liquid injection electronic expansion valve 12 is adjusted to be: (valve opening temperature-current discharge temperature Td of the compressor 1)/2 × calculation coefficient; if the exhaust temperature of the compressor 1 is in an ascending state or unchanged, the opening degree of the liquid-spraying electronic expansion valve 12 is not changed;
2.5) if the exhaust temperature Td of the compressor 1 is less than the valve closing temperature, the liquid spraying electromagnetic valve 11 and the liquid spraying electronic expansion valve 12 are closed.
Therefore, the opening degree of the main electronic expansion valve 6 and the opening degree of the liquid spraying electronic expansion valve 12 are flexibly controlled through the environment temperature and the exhaust temperature of the compressor 1, the flow of a refrigerant used for heat exchange in the main circuit and the auxiliary circuit of the unit is periodically adjusted, the problem that the unit cannot be started and is abnormally started due to overhigh exhaust temperature when the compressor 1 is started is further avoided, and the unit is started and operated at high temperature.
Further, in the step 2), when the liquid spraying plate controls the opening of the liquid spraying electronic expansion valve 12, the numerical value of the calculation coefficient is determined according to the temperature difference of the exhaust temperature of the compressor 1 in an interval period, and the larger the temperature difference of the exhaust temperature of the compressor 1 in an interval period is, the larger the value of the calculation numerical value is. Thus, the opening degree of the liquid spraying electronic expansion valve 12 can be flexibly adjusted, the flexibility of the control process is increased, and the exhaust temperature of the compressor 1 is stably reduced.
Further, in the above step 2.3), when the discharge temperature of the compressor 1 is in the rising state, the liquid jet electronic expansion valve 12 is increased by 3 opening degrees during adjustment. In this way, the control process of the unit is simplified while ensuring a reduction in the discharge temperature of the compressor 1.
The method for controlling the exhaust temperature of the compressor applied to the heat pump water heater comprises the main path for heat exchange, the auxiliary path for reducing the exhaust temperature, a main control board for controlling the flow of refrigerant in the main path and a liquid spraying board for controlling the flow of refrigerant in the auxiliary path. The heat exchanger also comprises a fan assembly 8 for accelerating heat exchange, an air suction sensor 9 and an exhaust sensor 2, wherein the air suction assembly is arranged on a pipeline connected with the compressor 1 and the four-way valve 3, and the air suction sensor 9 is arranged on a pipeline connected with the four-way valve 3 and the gas-liquid separator 10.
In this embodiment, when the compressor 1 is started, the main control board gives an initial opening degree to the main electronic expansion valve 6; the lower the ambient temperature of the compressor 1, the smaller the initial opening degree of the main circuit electronic expansion valve 6. This ensures a stable start-up of the compressor 1. The initial opening degree of the main electronic expansion valve 6 is shown in table 1; in table 1, values represented by opening i, opening ii, opening iii, opening iv, opening v, opening vi, opening vii, and opening viii were decreased one by one. When the opening degree of the main-path electronic expansion valve 6 is less than or equal to the opening degree of the electronic expansion valve at the current ambient temperature shown in table 1, the main control board stops controlling the opening degree of the main-path electronic expansion valve 6.
Table 1: comparison table of environmental temperature and main circuit electronic expansion valve 6 opening degree when compressor 1 starts
However, the unit may be in a special working environment, especially, under the condition that the unit works in the northern area, when the environment temperature of the liquid spraying compressor 1 is less than or equal to-10 ℃ and the water temperature in the unit is greater than or equal to 48 ℃, the exhaust temperature of the compressor 1 during starting is higher, the control of the liquid spraying plate cannot solve the problem that the exhaust temperature is too high at the starting moment, experiments verify that the exhaust temperature at the starting moment of the compressor 1 reaches the protection value (generally 120-125 ℃) specified by a compressor 1 manufacturer or is very close to the protection value, no safety margin exists, and once the exhaust temperature of the compressor 1 is higher than the protection value set by the compressor 1 manufacturer, the unit can start the compressor 1 in a self-protection state to cause the abnormal starting of the compressor 1. Taking 2 12 low-temperature liquid spraying compressors 1 as an example, as shown in fig. 2, when the compressor 1 is started instantaneously, peaks appear in both the exhaust temperature curve a of the first compressor and the exhaust temperature curve B of the second compressor, and the exhaust temperatures of the two compressors at the peak time respectively reach 123 ℃ and 120 ℃; as shown in Table 2, the instantaneous temperature of the compressor 1 when the compressor 1 is started is lower than or equal to-10 ℃ under the working conditions that the ambient temperature is lower than or equal to-10 ℃ and the water temperature in the unit is higher than or equal to 48 ℃;
table 2: under the working conditions of low ambient temperature and high unit water temperature, the instantaneous exhaust temperature is generated when the compressor 1 is started;
therefore, when the unit is started, the main control board readjusts the opening of the main electronic expansion valve 6; when the ambient temperature is more than or equal to-15 ℃ and less than 0 ℃ and the water temperature in the unit is more than or equal to 47 ℃, the initial opening degree of the main-circuit electronic expansion valve 6 is 300 degrees when the unit is started in the step 1), and the opening degree of the main-circuit electronic expansion valve 6 is periodically reduced after the unit operates for 2 min. When the ambient temperature is lower than-15 ℃ and the water temperature in the unit is higher than or equal to 42 ℃, the initial opening of the main electronic expansion valve 6 is 400 degrees when the unit is started in the step 1), and the opening of the main electronic expansion valve 6 is periodically reduced after the unit operates for 2 min. After the control method is operated, as shown in fig. 3, under the working condition that the environment temperature is-12 ℃ and the water temperature in the unit is 52 ℃, the peak of the exhaust temperature curve a of the first compressor and the peak of the exhaust temperature curve B of the second compressor are eliminated, and the highest exhaust temperatures of the two compressors are respectively 106 ℃ and 107 ℃. As shown in Table 3, the exhaust temperatures of the two compressors are compared as follows after the above control method is operated:
table 3: after one compressor exhaust temperature control method is operated, the exhaust temperature comparison table of two compressors
Thus, as can be confirmed from fig. 3 and table 3, after the unit operates the above method for controlling the exhaust temperature of the compressor, the exhaust temperature of the compressor 1 is significantly reduced, thereby avoiding the occurrence of unit failure starting or unit abnormal sound caused by the over-high exhaust temperature of the compressor 1, and improving the stability and safety of the unit and the adaptability of the unit in different environments.
In this embodiment, the maximum opening of the liquid ejection electronic expansion valve 12 during automatic adjustment is 480, and the minimum opening of the liquid ejection electronic expansion valve 12 during automatic adjustment is 60. Therefore, enough refrigerant is ensured in the main path, and the heat exchange efficiency of the unit is ensured.
In this embodiment, the interval period for adjusting the liquid injection electronic expansion valve 12 is 2 s. In this way, occurrence of overshoot and lag regulation is avoided, and the discharge temperature of the compressor 1 is stably lowered.
In this embodiment, the liquid-jet plate can independently perform step 2), and the main control plate can independently perform step 1); when the unit is in a special working condition, the liquid spraying plate and the main control plate operate simultaneously to control the exhaust temperature of the compressor 1. Thus, the control mode of the unit is more flexible,
in the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.
Claims (10)
1. A method for controlling the exhaust temperature of a compressor is characterized in that: the heat exchanger comprises a main path for heat exchange and an auxiliary path for reducing exhaust temperature, wherein a refrigerant on the main path sequentially passes through a compressor (1), a four-way valve (3), a double-pipe heat exchanger (4), a liquid storage device (5) and a fin evaporator (7), then enters a gas-liquid separator (5) through the four-way valve (3) again and then returns to the compressor (1), and a main path electronic expansion valve (6) for controlling the flow of the refrigerant of the main path is arranged on a pipeline connecting the liquid storage device (5) and the fin evaporator (7); one end of the auxiliary path is communicated with the liquid storage device (5) and one end of the main path electronic expansion valve (6), the other end of the auxiliary path is communicated with the air inlet of the compressor (1), the auxiliary path is provided with a liquid injection electronic expansion valve (12) and a liquid injection electromagnetic valve (11), and a refrigerant in the auxiliary path enters the air inlet of the compressor (1) after passing through the liquid injection electromagnetic valve (11) and the liquid injection electronic expansion valve (12) in sequence; when the compressor (1) is started under the conditions of low ambient temperature and high water temperature in the unit, the control method comprises the following steps:
1) main-path control: determining the initial opening degree of the main electronic expansion valve (6) according to the outdoor environment temperature and the water temperature in the unit, immediately reducing the N opening degree of the main electronic expansion valve (6) after the compressor (1) is started for 2min, and then reducing the N opening degree of the main electronic expansion valve (6) at intervals of a time period T until the opening degree of the main electronic expansion valve (6) is not greater than the opening degree of the main electronic expansion valve (6) set by a system when the compressor (1) is started at the current environment temperature;
2) auxiliary road control: when the exhaust temperature of the compressor (1) is higher than the preset valve opening temperature of the system, the auxiliary electromagnetic valve is opened, the expansion valve is opened, and the opening degree of the liquid spraying electronic expansion valve (12) is controlled according to the exhaust temperature interval of the compressor (1) in the subsequent process; during the regulation of the electronic liquid injection expansion valve (12),
2.1) when the valve opening temperature is less than the exhaust temperature Td of the compressor (1) and less than or equal to the valve opening temperature and a temperature control value, if the exhaust temperature of the compressor (1) is in an ascending state, the opening degree of the liquid spraying electronic expansion valve (12) is adjusted as follows: (exhaust temperature Td-valve opening temperature of the compressor (1) at present) x calculation coefficient; if the exhaust temperature of the compressor (1) is in a descending state or unchanged, the opening degree of the liquid spraying electronic expansion valve (12) is unchanged;
2.2) when the exhaust temperature Td of the compressor (1) is more than the valve opening temperature and the temperature control value is satisfied, if the exhaust temperature of the compressor (1) is in an ascending state or is not changed, the opening degree of the liquid spraying electronic expansion valve (12) is adjusted as follows: (exhaust temperature Td-valve opening temperature of the compressor (1) at present) x calculation coefficient; if the exhaust temperature of the compressor (1) is in a descending state, the opening degree of the liquid injection electronic expansion valve (12) is unchanged;
2.3) when the valve opening temperature-temperature control value is less than the current exhaust temperature Td of the compressor (1) and less than or equal to the valve opening temperature, if the exhaust temperature of the compressor (1) is in a descending state, reducing the opening degree of the liquid injection electronic expansion valve (12), and adjusting the opening degree of the liquid injection electronic expansion valve (12) to be as follows: (valve opening temperature-current discharge temperature Td of the compressor (1))/2 x calculation coefficient; if the exhaust temperature of the compressor (1) is not changed, the opening degree of the liquid spraying electronic expansion valve (12) is not changed; if the exhaust temperature of the compressor (1) is in a rising state, the opening rating of the liquid injection electronic expansion valve (12) is increased;
2.4) when the exhaust temperature Td of the compressor (1) is less than or equal to the valve opening temperature-the temperature control value is satisfied, if the exhaust temperature of the compressor (1) is in a descending state, the opening degree of the liquid spraying electronic expansion valve (12) is reduced, and the opening degree of the liquid spraying electronic expansion valve (12) is adjusted as follows: (valve opening temperature-current discharge temperature Td of the compressor (1))/2 x calculation coefficient; if the exhaust temperature of the compressor (1) is in an ascending state or is unchanged, the opening degree of the liquid-spraying electronic expansion valve (12) is not changed;
2.5) if the exhaust temperature Td of the current compressor (1) is less than the valve closing temperature, closing the liquid spraying electromagnetic valve (11) and the liquid spraying electronic expansion valve (12).
2. A compressor discharge temperature control method as claimed in claim 1, wherein: in the step 1), when the ambient temperature is more than or equal to minus 15 ℃ and less than 0 ℃ and the water temperature in the unit is more than or equal to 47 ℃, the initial pulse of the main electronic expansion valve (6) is 300 degrees of opening when the unit is started, and the opening of the main electronic expansion valve (6) is periodically reduced after the unit operates for 2 min.
3. A compressor discharge temperature control method as claimed in claim 1, wherein: in the step 1), when the environmental temperature is less than-15 ℃ and the water temperature in the unit is more than or equal to 42 ℃, the initial pulse of the main circuit electronic expansion valve (6) is 400 degrees when the unit is started, and the degree of opening of the main circuit electronic expansion valve (6) is periodically reduced after the unit operates for 2 min.
4. A compressor discharge temperature control method as claimed in claim 1, wherein: in the step 1), the lower the ambient temperature of the compressor (1), the smaller the initial opening degree of the main electronic expansion valve (6).
5. The compressor discharge temperature control method as claimed in claim 4, wherein: the maximum opening degree of the liquid spraying electronic expansion valve (12) in automatic adjustment is 480, and the minimum opening degree of the liquid spraying electronic expansion valve (12) in automatic adjustment is 60.
6. A compressor discharge temperature control method as claimed in claim 1, wherein: the interval period of the adjustment of the liquid injection electronic expansion valve (12) is 2 s.
7. A compressor discharge temperature control method as claimed in claim 1, wherein: in the step 2), the value of the calculation coefficient is determined according to the temperature difference of the exhaust temperature of the compressor in an interval period, and the larger the temperature difference is, the larger the value of the calculation value is.
8. A compressor discharge temperature control method as claimed in claim 1, wherein: in the step 2.3), if the exhaust temperature of the compressor (1) is in a rising state, the liquid injection electronic expansion valve (12) is increased by 3 opening degrees during adjustment.
9. A compressor discharge temperature control method as claimed in claim 1, wherein: the main road control method in the step 1) and the auxiliary road control method in the step 2) can be independently operated and controlled.
10. A heat pump water heater to which a compressor discharge temperature control method according to any one of claims 1 to 9 is applied, characterized in that: comprising a main path for heat exchange and a secondary path for reducing the temperature of the exhaust gas.
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Cited By (1)
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| CN116007193A (en) * | 2022-12-13 | 2023-04-25 | 珠海格力电器股份有限公司 | Control method and device of heat pump water heater, heat pump water heater and storage medium |
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