CN111780457B - Control method for low water temperature starting of heat pump system - Google Patents
Control method for low water temperature starting of heat pump system Download PDFInfo
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- CN111780457B CN111780457B CN202010475353.2A CN202010475353A CN111780457B CN 111780457 B CN111780457 B CN 111780457B CN 202010475353 A CN202010475353 A CN 202010475353A CN 111780457 B CN111780457 B CN 111780457B
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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
- F25B30/00—Heat pumps
- F25B30/02—Heat pumps of the compression type
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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
- 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
- F25B49/022—Compressor control arrangements
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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
- F25B2600/02—Compressor control
- F25B2600/021—Inverters therefor
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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
- F25B2600/2513—Expansion valves
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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
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention provides a control method for low water temperature starting of a heat pump system, wherein the low-temperature stage heat pump system comprises a controller, a low-temperature stage compressor, a main circuit electronic expansion valve, an enthalpy-increasing auxiliary circuit electronic expansion valve, an outdoor environment temperature-sensing sensor, a water inlet temperature-sensing sensor and a water outlet temperature-sensing sensor, the controller is connected with the low-temperature stage compressor, the main-path electronic expansion valve, the enthalpy-increasing auxiliary-path electronic expansion valve, the outdoor environment temperature sensor, the water inlet temperature sensor and the water outlet temperature sensor, the water inlet temperature-sensing sensor and the water outlet temperature-sensing sensor are respectively arranged at the water inlet end and the water outlet end of the energy consumption tail end, the control method for starting the low water temperature adopts a first-stage low pressure removing step and a second-stage low pressure removing step to realize that the low pressure gradually returns to normal because the frequency of the low-temperature stage compressor is limited to F1, the frequency rises only after the condition is reached, so that no too low negative influence is caused on the low-pressure.
Description
Technical Field
The invention relates to the technical field of heat pump systems, in particular to a control method for low water temperature starting of a heat pump system.
Background
Basic principle of the existing heat pump system: the device mainly comprises a compressor, a condenser, an axial fan, an evaporator, a heat preservation water tank, a water pump, a liquid storage tank, a filter, an electronic expansion valve, an electronic automatic controller and the like. After the power is turned on, the axial flow fan starts to operate, outdoor air is subjected to heat exchange through the evaporator, and the air with the reduced temperature is discharged out of the system by the fan. Meanwhile, the working medium in the evaporator absorbs heat to be vaporized and is sucked into the compressor, the compressor compresses the low-pressure working medium gas into high-temperature and high-pressure gas and sends the high-temperature and high-pressure gas into the condenser, water forced to circulate by the water pump also passes through the condenser, is heated by the working medium and then is sent to a user for use, the working medium is cooled into liquid, the liquid flows into the evaporator again after being throttled and cooled by the electronic expansion valve, and the circulation work is repeated. The heat energy in the air is continuously transmitted into the water, so that the water temperature in the heat-insulating water tank is gradually increased, and the water can reach the use temperature suitable for people.
However, the above-described conventional heat pump system has the following disadvantages in practical control use: when the low-temperature stage compressor is started at low ambient temperature and low water temperature, because the low-pressure is too low, if the low pressure is continuously lower according to the raising speed of the original low-temperature stage compressor, the main machine cannot heat normally, even if the frequency reaches the target frequency and continuously operates, the low-pressure cannot be raised, and finally the main machine is stopped, so that the use is seriously influenced.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a control method for low water temperature starting of a heat pump system, which can judge the required decompression level according to the actual situation and solve the negative influence of the shutdown of a main machine caused by too low pressure.
The invention aims to realize the following steps: the control method for low-water-temperature starting of the heat pump system comprises a controller, a low-temperature-stage compressor, a main-circuit electronic expansion valve, an enthalpy-increasing auxiliary-circuit electronic expansion valve, an outdoor environment temperature-sensing sensor, a water inlet temperature-sensing sensor and a water outlet temperature-sensing sensor, wherein the controller is connected with the low-temperature-stage compressor, the main-circuit electronic expansion valve, the enthalpy-increasing auxiliary-circuit electronic expansion valve, the outdoor environment temperature-sensing sensor, the water inlet temperature-sensing sensor and the water outlet temperature-sensing sensor are respectively installed at a water inlet end and a water outlet end of an energy-consuming tail end, and the control method for low-water-temperature starting comprises the following steps:
(1) a first-stage low pressure relieving step: detecting a current inlet water temperature Ti and an outdoor environment temperature T0, when the inlet water temperature Ti is less than or equal to a first set temperature T1 and the outdoor environment temperature T0 is less than or equal to a second set temperature T2, controlling the opening step number of the main electronic expansion valve to be limited to S1 steps and the opening step number of the enthalpy-increasing auxiliary electronic expansion valve to be limited to S2 steps to close the main electronic expansion valve, starting the low-temperature-stage compressor at the moment, limiting the highest operation frequency of the low-temperature-stage compressor to be F1, and when the inlet water temperature Ti is greater than the first set temperature T1 and the outdoor environment temperature T0 is greater than the second set temperature T2, increasing the frequency of the low-temperature-stage compressor to a target frequency Fm to operate;
(2) a secondary low pressure relieving step: when the low-temperature stage compressor continuously operates at a target frequency F1, detecting the exhaust temperature Tp of the current low-temperature stage compressor in real time; when the exhaust temperature Tp of the low-temperature stage compressor is not less than the third set temperature T3 and the duration is not less than the first set time T1, controlling the low-temperature stage compressor to be in the frequency increasing mode to the target frequency Fm to operate by the controller; when the discharge temperature Tp of the low-temperature-stage compressor is less than the third set temperature T3 and the duration is less than the first set time T1, the low-temperature-stage compressor operates at the frequency F1, and the duration is greater than or equal to the second set time T2, the controller controls the low-temperature-stage compressor to be in the frequency increasing mode to the target frequency Fm.
According to the optimization, in the step of primary low pressure relief, the first set temperature is 15 ℃ and T1 which are less than 25 ℃, and the second set temperature is: 10 < T2<20 ℃, main circuit electronic expansion valve opening step number limit: s1 ≦ 90 steps, limiting the opening step number of the auxiliary electronic expansion valve: and S2 is 0 step, the controller controls the low-temperature stage compressor to start, and the maximum operation frequency of the low-temperature stage compressor is limited: f1 ≦ 55Hz, target frequency for cryogenic stage compressor: fm ≦ 95 Hz.
According to the optimization, the first set temperature T1 is 20 ℃, and the second set temperature: t2 is 15 ℃, the main circuit electronic expansion valve opening step number limit S1 is 90 steps, the maximum operating frequency limit of the cryogenic stage compressor: f1 is 55Hz, maximum target frequency of the low temperature stage compressor: fm is 95 Hz.
According to the optimization, in the step of secondary low pressure relief, the first set time is as follows: 15s < t1<25s, second set time: 15min < t2<25 min.
Optimizing according to the above, the first set time: t1 is 20s, second set time: t2 is 20 min.
According to the optimization, in the step of secondary low pressure relief, the third set temperature is: 45 ℃ < T3<55 ℃.
Optimized according to the above, the third set temperature is: t3 was 50 ℃.
According to the optimization, the control method for the low water temperature starting further comprises a defrosting operation step, after the defrosting operation, a secondary low pressure removing step is carried out, the exhaust temperature Tp of the low-temperature stage compressor is detected, the low-temperature stage compressor normally operates according to the frequency F1 after the exhaust temperature Tp is not less than 50 ℃, the secondary low pressure removing step is carried out after the exhaust temperature Tp is maintained at t2, and the low-temperature stage compressor is subjected to frequency rising to the target frequency Fm to operate.
The invention has the advantages that: by adopting the control method, the low-pressure is gradually restored to be normal because the frequency of the low-temperature stage compressor is limited to F1, and the frequency is increased after the condition is reached, so that the low-pressure is not influenced excessively.
Drawings
Fig. 1 is a schematic diagram of the operation of the preferred embodiment of the present invention.
FIG. 2 is a graph showing the relationship between the low-temperature stage compressor and the discharge temperature according to the preferred embodiment of the present invention.
FIG. 3 is a graph showing the relationship between the opening of the main electronic expansion valve and the time variation according to the preferred embodiment of the present invention.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
According to the attached drawings 1 to 3, the control method for low water temperature starting of the heat pump system of the invention comprises a controller, a low temperature stage compressor, a main circuit electronic expansion valve, an enthalpy-increasing auxiliary circuit electronic expansion valve, an outdoor environment temperature sensor, a water inlet temperature sensor and a water outlet temperature sensor, wherein the controller is connected with the low temperature stage compressor, the main circuit electronic expansion valve, the enthalpy-increasing auxiliary circuit electronic expansion valve, the outdoor environment temperature sensor, the water inlet temperature sensor and the water outlet temperature sensor, and the water inlet temperature sensor and the water outlet temperature sensor are respectively arranged at a water inlet end and a water outlet end of an energy consumption tail end, wherein the control method for low water temperature starting comprises the following steps:
(1) a first-stage low pressure relieving step: and detecting the current water inlet temperature Ti and the outdoor environment temperature T0, and when the water inlet temperature Ti is less than or equal to a first set temperature T1 and the outdoor environment temperature T0 is less than or equal to a second set temperature T2, controlling the opening step number of the main electronic expansion valve to be limited to S1 steps and controlling the opening step number of the enthalpy-increasing auxiliary electronic expansion valve to be limited to S2 steps to close. The low-temperature-stage compressor at this time is started and the maximum operation frequency of the low-temperature-stage compressor is limited to F1, and the low-temperature-stage compressor is up-converted to the target frequency Fm operation when the intake water temperature Ti > the first set temperature T1 and the outdoor ambient temperature T0> the second set temperature T2.
(2) A secondary low pressure relieving step: when the low-temperature stage compressor is continuously operated at the target frequency F1, the discharge temperature Tp of the current low-temperature stage compressor is detected in real time. When the discharge temperature Tp of the low-temperature-stage compressor is larger than or equal to the third set temperature T3 and the duration is larger than or equal to the first set time T1, the controller controls the low-temperature-stage compressor to be in the up-conversion mode to the target frequency Fm. When the discharge temperature Tp of the low-temperature-stage compressor is less than the third set temperature T3 and the duration is less than the first set time T1, the low-temperature-stage compressor operates at the frequency F1, and the duration is not less than the second set time T2, and the controller controls the low-temperature-stage compressor to be in the frequency increasing mode until the target frequency Fm is operated.
Wherein, in the step of first-stage low pressure relief, the first set temperature is 15 ℃ and T1 and 25 ℃, and the second set temperature is: 10 < T2<20 ℃, main circuit electronic expansion valve opening step number limit: s1 ≦ 90 steps, limiting the opening step number of the auxiliary electronic expansion valve: and S2 is 0 step, the controller controls the low-temperature stage compressor to start, and the maximum operation frequency of the low-temperature stage compressor is limited: f1 ≦ 55Hz, target frequency for cryogenic stage compressor: fm ≦ 95 Hz. In the secondary low pressure relief step, the first set time is: 15s < t1<25s, second set time: 15min < t2<25 min. The third set temperature: 45 ℃ < T3<55 ℃.
In the practical optimization scheme, the first set temperature T1 is 20 ℃, and the second set temperature: t2 is 15 ℃, the main circuit electronic expansion valve opening step number limit S1 is 90 steps, the maximum operating frequency limit of the cryogenic stage compressor: f1 is 55Hz, maximum target frequency of the low temperature stage compressor: fm is 95 Hz. The first set time is: t1 is 20s, second set time: t2 is 20 min. The third set temperature: t3 was 50 ℃.
That is, when the heat pump is started at a low ambient temperature and a low water temperature, the current inlet water temperature Ti and the outdoor ambient temperature T0 are detected in real time. And when the water inlet temperature Ti is less than or equal to 20 ℃ and the outdoor environment temperature T0 is less than or equal to 15 ℃, entering a first-stage low pressure removing step. The controller controls the opening step number of the main electronic expansion valve to be limited to 90 steps, and the opening step number of the enthalpy-increasing auxiliary electronic expansion valve to be limited to 0 step to close. At this time, the low temperature stage compressor is started and the low temperature stage compressor is continuously operated with the maximum operation frequency limited to 55 Hz. If the inlet water temperature Ti is more than 20 ℃ and the outdoor environment temperature T0 is more than 15 ℃, the low-temperature stage compressor is increased to the maximum target frequency of 95Hz for operation.
During continuous operation, the current discharge temperature Tp of the low-temperature stage compressor is detected in real time. And when the exhaust temperature Tp of the low-temperature stage compressor rises by more than or equal to 50 ℃ and the duration is more than or equal to 20s, the first-stage decompression step is exited, the second-stage decompression step is entered, and the controller controls the low-temperature stage compressor to operate when the low-temperature stage compressor rises to the target frequency of 95 Hz. When the exhaust temperature Tp of the low-temperature stage compressor is less than 50 ℃ and the duration is less than 20s, the low-temperature stage compressor operates at the frequency of F1, when the duration is greater than or equal to 20min, the first-stage decompression step is also exited, the second-stage decompression step is entered, and the controller controls the low-temperature stage compressor to be operated at the target frequency of 95 Hz.
Thus, by adopting the control method, the low-pressure is gradually restored to be normal because the frequency of the low-temperature stage compressor is limited to 55Hz, and the frequency is increased after the condition is reached, so that the low-pressure is not influenced excessively.
The above embodiments are only embodiments with better effects, and all the structures that are the same as or equivalent to the control method for the low water temperature start of the heat pump system of the present invention are within the protection scope of the present invention.
Claims (6)
1. A control method for low-temperature starting of a heat pump system is characterized in that the low-temperature stage heat pump system comprises a controller, a low-temperature stage compressor, a main electronic expansion valve, an enthalpy-increasing auxiliary electronic expansion valve, an outdoor environment temperature sensor, a water inlet temperature sensor and a water outlet temperature sensor, the controller is connected with the low-temperature stage compressor, the main electronic expansion valve, the enthalpy-increasing auxiliary electronic expansion valve, the outdoor environment temperature sensor, the water inlet temperature sensor and the water outlet temperature sensor, and the water inlet temperature sensor and the water outlet temperature sensor are respectively installed at a water inlet end and a water outlet end of an energy consumption tail end, and the control method is characterized in that: the control method for starting the low water temperature comprises the following steps:
(1) a first-stage low pressure relieving step: detecting a current inlet water temperature Ti and an outdoor environment temperature T0, when the inlet water temperature Ti is less than or equal to a first set temperature T1 and the outdoor environment temperature T0 is less than or equal to a second set temperature T2, controlling the opening step number of the main electronic expansion valve to be limited to S1 steps and the opening step number of the enthalpy-increasing auxiliary electronic expansion valve to be limited to S2 steps to close the main electronic expansion valve, starting the low-temperature-stage compressor at the moment, limiting the highest operation frequency of the low-temperature-stage compressor to be F1, and when the inlet water temperature Ti is greater than the first set temperature T1 and the outdoor environment temperature T0 is greater than the second set temperature T2, increasing the frequency of the low-temperature-stage compressor to a target frequency Fm to operate;
(2) a secondary low pressure relieving step: when the low-temperature stage compressor continuously operates at a target frequency F1, detecting the exhaust temperature Tp of the current low-temperature stage compressor in real time; when the exhaust temperature Tp of the low-temperature stage compressor is not less than the third set temperature T3 and the duration is not less than the first set time T1, controlling the low-temperature stage compressor to be in the frequency increasing mode to the target frequency Fm to operate by the controller; when the discharge temperature Tp of the low-temperature-stage compressor is less than the third set temperature T3 and the duration is less than the first set time T1, the low-temperature-stage compressor operates at the frequency F1, and the duration is ≧ the second set time T2, the controller controls the low-temperature-stage compressor to be in the frequency up-conversion operation at the target frequency Fm;
in the first low pressure relief step, the first set temperature is 15 ℃ < T1<25 ℃, the second set temperature is: 10 < T2<20 ℃, main circuit electronic expansion valve opening step number limit: s1 ≦ 90 steps, limiting the opening step number of the auxiliary electronic expansion valve: and S2 is 0 step, the controller controls the low-temperature stage compressor to start, and the maximum operation frequency of the low-temperature stage compressor is limited: f1 ≦ 55Hz, target frequency for cryogenic stage compressor: fm ≦ 95 Hz;
the control method for starting the low water temperature further comprises a defrosting operation step, after the defrosting operation, a secondary low pressure removing step is carried out, the exhaust temperature Tp of the low-temperature stage compressor is detected, the low-temperature stage compressor normally operates according to the frequency F1 after the exhaust temperature Tp is not less than 50 ℃, the secondary low pressure removing step is carried out after the exhaust temperature Tp is maintained at t2, and the low-temperature stage compressor is increased to the target frequency Fm for operation.
2. The control method for the low water temperature start of the heat pump system according to claim 1, characterized in that: t1 is 20 ℃, and the second set temperature is: t2 is 15 ℃, the main circuit electronic expansion valve opening step number limit S1 is 90 steps, the maximum operating frequency limit of the cryogenic stage compressor: f1 is 55Hz, maximum target frequency of the low temperature stage compressor: fm is 95 Hz.
3. The control method for the low water temperature start of the heat pump system according to claim 1, characterized in that: in the secondary low pressure relief step, the first set time is: 15s < t1<25s, second set time: 15min < t2<25 min.
4. The control method for the low water temperature start of the heat pump system according to claim 3, characterized in that: the first set time is: t1 is 20s, second set time: t2 is 20 min.
5. The control method for the low water temperature start of the heat pump system according to claim 1, characterized in that: in the secondary de-pressurization step, the third set temperature is: 45 ℃ < T3<55 ℃.
6. The control method for the low water temperature start of the heat pump system according to claim 5, characterized in that: the third set temperature: t3 was 50 ℃.
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| CN113483385B (en) * | 2021-07-02 | 2022-10-04 | 青岛海信日立空调系统有限公司 | Air source heat pump unit |
| CN114165942A (en) * | 2021-11-22 | 2022-03-11 | 青岛海信日立空调系统有限公司 | Heat pump set |
| CN115077131B (en) * | 2022-04-29 | 2024-07-05 | 浙江中广电器集团股份有限公司 | Air source heat pump system with economizer and exhaust gas temperature control method |
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| US6945062B2 (en) * | 2003-12-04 | 2005-09-20 | Carrier Corporation | Heat pump water heating system including a compressor having a variable clearance volume |
| JP2006317038A (en) * | 2005-05-11 | 2006-11-24 | Matsushita Electric Ind Co Ltd | Heat pump type water heater |
| CN106482412A (en) * | 2016-09-23 | 2017-03-08 | 广东美的暖通设备有限公司 | Source pump and its low-temperature start method of compressor and device |
| CN106996665B (en) * | 2017-03-22 | 2019-10-01 | 珠海格力电器股份有限公司 | Compressor starting method and device and terminal |
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