A high-efficiency control method for an air source heat pump system

Abstract

The application discloses a kind of air source heat pump system high-efficiency control method, including heat pump system and its auxiliary heat source start-up area, load following area, load unloading area;The system is compared according to the acquisition outdoor environment temperature and preset first temperature, preset second temperature, and simultaneously compared with the continuous operation time of air source heat pump in high frequency interval and preset first time, and compared with the continuous operation time of air source heat pump in low frequency interval and preset second time, determine and decide the operating condition of heat pump system, ensure that heat pump system is in optimal, most energy-saving operating state.In load unloading area, by adjusting heat pump return difference temperature, reduce the number of compressor start-up in unit time, effectively prevent compressor start-stop too frequently, improve the service life of compressor, bring good experience for heating terminal.

Description

Technical Field

[0001] This invention relates to the field of heat pump system technology, and in particular to a high-efficiency control method for an air source heat pump system. Background Technology

[0002] Heat pump heating systems typically control their operation by judging the return water temperature. The system shuts down when the return water temperature reaches the set value and restarts when the return water temperature falls below the set value and the hysteresis temperature difference. During the heating season, the total heating load fluctuates constantly. If the heat pump has a high power rating, it will cause the compressor to start and stop frequently, reducing its lifespan and resulting in poor economic efficiency. If the heat pump has a low power rating, the auxiliary heat source needs to be upgraded, which cannot fully utilize the heat pump's high-efficiency heating advantage and increases energy consumption. Summary of the Invention

[0003] To overcome the shortcomings mentioned above, this invention aims to provide an efficient control method for an air source heat pump system that fully utilizes the performance of the heat pump, activates the auxiliary heat source when the outdoor temperature is low, and reduces the number of compressor starts per unit time by adjusting the heat pump hysteresis temperature when the outdoor temperature is high, thereby effectively preventing frequent compressor start-stop.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a high-efficiency control method for an air source heat pump system, comprising an air source heat pump system and its auxiliary heat source start-up zone, load following zone, and load unloading zone; the air source heat pump system includes an air source heat pump, an auxiliary heat source, a circulating pump, heating terminals, and installation accessories;

[0005] S1. Compare the outdoor ambient temperature with the preset first temperature, and compare the continuous running time of the air source heat pump in the high frequency range with the preset first time to determine whether the heat pump system has entered the auxiliary heat source start-up zone.

[0006] S2. Obtain the outdoor ambient temperature and compare it with the preset second temperature, and obtain the continuous operating time of the air source heat pump in the low frequency range and compare it with the preset second time to determine whether the heat pump system has entered the load unloading zone.

[0007] S3. If the air source heat pump is not operating in the auxiliary heat source start-up zone or the load unloading zone, the heat pump system will enter the load following zone.

[0008] If the heat pump system enters the auxiliary heat source start-up zone, the auxiliary heat source will be started at the same time as the heat pump is running;

[0009] If the heat pump system enters the load following zone, the heat pump will adjust its operating frequency in real time according to the load change.

[0010] If the heat pump system enters the load unloading zone, the heat pump adjusts the hysteresis temperature based on the number of times the compressor starts.

[0011] As a further aspect of the present invention: if the obtained outdoor ambient temperature is less than a preset first temperature and the air source heat pump operates continuously in the high frequency range for a time longer than a preset first time, the heat pump system enters the auxiliary heat source start-up zone; if the outdoor ambient temperature is greater than or equal to the preset first temperature, the heat pump system leaves the auxiliary heat source start-up zone.

[0012] As a further embodiment of the present invention: if the obtained outdoor ambient temperature is greater than a preset second temperature and the air source heat pump operates continuously in the low frequency range for a time longer than a preset second time, the heat pump system enters the load unloading zone; if the outdoor ambient temperature is less than or equal to the preset second temperature, the heat pump system leaves the load unloading zone.

[0013] As a further aspect of the present invention: the preset first temperature is less than the preset second temperature.

[0014] As a further aspect of the present invention: when the heat pump system enters the load unloading zone, the number of compressor starts is recorded; the heat pump hysteresis temperature corresponding to the next unit time is adjusted according to the number of compressor starts per unit time.

[0015] As a further embodiment of the present invention: when the heat pump system enters the load following zone or the auxiliary heat source start-up zone, the heat pump hysteresis temperature is restored to the system set value.

[0016] As a further embodiment of the present invention: the air source heat pump system adopts a variable frequency compressor, and the heat pump system is set with a high frequency range and a low frequency range, and the high frequency range and the low frequency range do not overlap.

[0017] The beneficial effects of this invention are as follows: This system compares the acquired outdoor ambient temperature with preset first and second temperatures, and simultaneously compares the continuous operating time of the air source heat pump in the high-frequency range with a preset first time, and the continuous operating time of the air source heat pump in the low-frequency range with a preset second time, to determine and decide the operating condition of the heat pump system, ensuring that the heat pump system operates in the optimal and most energy-efficient state. In the load unloading zone, by adjusting the heat pump hysteresis temperature, the number of compressor starts per unit time is reduced, effectively preventing excessively frequent compressor start-stops, improving compressor lifespan, and providing a better experience for heating terminals. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 This is a schematic diagram of the working area division of the air source heat pump system of the present invention;

[0020] Figure 2This is a schematic diagram of the air source heat pump system of the present invention;

[0021] Figure 3 This is a schematic diagram of the working process of the single-cycle air source heat pump system of the present invention;

[0022] Figure 4 This is a table showing the relationship between the number of compressor starts and the hysteresis temperature of the heat pump according to the present invention.

[0023] Figure 1 In the middle: 1-Auxiliary heat source start-up zone, 2-Load following zone, 3-Load unloading zone, 4-Preset first temperature, 5-Preset second temperature, 6-Heat pump highest frequency heating curve, 7-Heat pump lowest frequency heating curve, 8-Total load curve.

[0024] Figure 2 In the middle: 9-Air source heat pump, 10-Auxiliary heat source, 11-Circulation pump, 12-Heating terminal. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] Please see the appendix Figure 1 - Appendix Figure 4 In this embodiment of the invention, an efficient control method for an air source heat pump system includes an air source heat pump system and its auxiliary heat source start-up zone 1, load following zone 2, and load unloading zone 3. The air source heat pump system includes an air source heat pump 9, an auxiliary heat source 10, a circulation pump 11, heating terminals 12, and installation accessories; the air source heat pump adopts a variable frequency compressor. The highest frequency heating curve 6 is the heating curve of the heat pump when it operates at its highest frequency, and the lowest frequency heating curve 7 is the heating curve of the heat pump when it operates at its lowest frequency; the total load curve 8 is the total heat consumption curve of the heating terminals.

[0027] In this embodiment, the highest operating frequency of the heat pump is 50Hz, and the lowest operating frequency is 20Hz.

[0028] S1. The preset first temperature is the outdoor ambient temperature value at the intersection of the heat pump's highest frequency heating curve 6 and the total load curve 8; the outdoor ambient temperature is compared with the preset first temperature 4, and the continuous running time of the air source heat pump in the high frequency range is compared with the preset first time to determine whether the heat pump system has entered the auxiliary heat source start-up zone; the high frequency range is 45Hz-50Hz, the preset first temperature is -15℃, and the preset first time is 10min;

[0029] If the outdoor ambient temperature is lower than a preset first temperature and the air source heat pump operates continuously in the high-frequency range for a time longer than a preset first time, the heat pump system enters the auxiliary heat source start-up zone. If the heat pump system enters the auxiliary heat source start-up zone, the auxiliary heat source is started while the heat pump is running. If the outdoor ambient temperature is greater than or equal to the preset first temperature, the heat pump system leaves the auxiliary heat source start-up zone.

[0030] The heat pump system enters the auxiliary heat source start-up zone, and the heat pump hysteresis temperature returns to the system set value.

[0031] In this embodiment, the heat pump system enters the auxiliary heat source start-up zone, and the heat pump hysteresis temperature returns to the system set value of 5°C.

[0032] S2. The preset second temperature is the outdoor ambient temperature value at the intersection of the lowest frequency heating curve 7 and the total load curve 8 of the heat pump. The preset first temperature is less than the preset second temperature 8. The outdoor ambient temperature is obtained and compared with the preset second temperature, and the continuous running time of the air source heat pump in the low frequency range is obtained and compared with the preset second time to determine whether the heat pump system has entered the load unloading zone. The low frequency range is 20Hz-25Hz, the preset second temperature is 5℃, and the preset second time is 10min.

[0033] If the outdoor ambient temperature is greater than the preset second temperature and the air source heat pump runs continuously in the low frequency range for a longer than the preset second time, the heat pump system enters the load unloading zone. If the heat pump system enters the load unloading zone, the number of compressor starts is recorded. The heat pump hysteresis temperature corresponding to the next unit time is adjusted according to the number of compressor starts per unit time.

[0034] In this embodiment, the number of times the compressor starts per unit time refers to the number of times the compressor starts per hour.

[0035] In this embodiment, if the compressor starts less than or equal to 2 times in one hour, the corresponding heat pump hysteresis temperature for the next hour is adjusted to 5°C; if the compressor starts 3 times in one hour, the corresponding heat pump hysteresis temperature for the next hour is adjusted to 6°C; if the compressor starts 4 times in one hour, the corresponding heat pump hysteresis temperature for the next hour is adjusted to 7°C; if the compressor starts 5 times in one hour, the corresponding heat pump hysteresis temperature for the next hour is adjusted to 8°C; if the compressor starts 6 times or more in one hour, the corresponding heat pump hysteresis temperature for the next hour is adjusted to 9°C.

[0036] When the outdoor ambient temperature is less than or equal to the preset second temperature, the heat pump system leaves the load unloading zone.

[0037] S3. If the air source heat pump is not operating in the auxiliary heat source start-up zone or the load unloading zone, the heat pump system enters the load following zone; the heat pump adjusts its operating frequency in real time according to the load changes.

[0038] The heat pump system enters the load following zone, and the heat pump hysteresis temperature returns to the system set value.

[0039] In this embodiment, the heat pump system enters the load following zone, and the heat pump hysteresis temperature returns to the system set value of 5°C.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0041] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency control method for an air source heat pump system, characterized in that, It includes an air source heat pump system and its auxiliary heat source start-up zone (1), load following zone (2), and load unloading zone (3); the air source heat pump system includes an air source heat pump (9), an auxiliary heat source (10), a circulating pump (11), a heating terminal (12), and installation accessories; S1. Compare the outdoor ambient temperature with the preset first temperature (4), and compare the continuous running time of the air source heat pump in the high frequency range with the preset first time to determine whether the heat pump system has entered the auxiliary heat source start-up zone. S2. Compare the outdoor ambient temperature with the preset second temperature (5), and compare the continuous running time of the air source heat pump in the low frequency range with the preset second time to determine whether the heat pump system has entered the load unloading zone. S3. If the air source heat pump is not operating in the auxiliary heat source start-up zone or the load unloading zone, the heat pump system will enter the load following zone. If the heat pump system enters the auxiliary heat source start-up zone, the auxiliary heat source will be started at the same time as the heat pump is running; If the heat pump system enters the load following zone, the heat pump will adjust its operating frequency in real time according to the load change. If the heat pump system enters the load unloading zone, the heat pump adjusts the heat pump hysteresis temperature according to the number of compressor starts. When the obtained outdoor ambient temperature is lower than the preset first temperature and the air source heat pump runs continuously in the high frequency range for a longer than the preset first time, the heat pump system enters the auxiliary heat source start-up zone. If the outdoor ambient temperature is greater than or equal to the preset first temperature, the heat pump system leaves the auxiliary heat source start-up zone.

2. The high-efficiency control method for an air source heat pump system according to claim 1, characterized in that, If the outdoor ambient temperature is greater than the preset second temperature and the air source heat pump operates continuously in the low frequency range for a longer than the preset second time, the heat pump system enters the load unloading zone; if the outdoor ambient temperature is less than or equal to the preset second temperature, the heat pump system leaves the load unloading zone.

3. The high-efficiency control method for an air source heat pump system according to claim 2, characterized in that, The preset first temperature is less than the preset second temperature.

4. The high-efficiency control method for an air source heat pump system according to claim 1, characterized in that, The heat pump system enters the load unloading zone, and the number of compressor starts is recorded. Adjust the heat pump hysteresis temperature for the next unit of time based on the number of times the compressor starts per unit time.

5. The high-efficiency control method for an air source heat pump system according to claim 1, characterized in that, When the heat pump system enters the load following zone or the auxiliary heat source start-up zone, the heat pump hysteresis temperature returns to the system set value.

6. The high-efficiency control method for an air source heat pump system according to claim 1, characterized in that, The air source heat pump uses a variable frequency compressor and sets a high frequency range and a low frequency range through the heat pump system, and the high frequency range and the low frequency range do not overlap.

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