Energy storage water chiller for optimizing low-temperature refrigeration and control method thereof

Abstract

The present application belongs to the technical field of thermal management of energy storage batteries, and particularly relates to an energy storage water chiller with optimized low-temperature refrigeration and a control method thereof. The energy storage water chiller comprises an electric louver, wherein the electric louver is installed on the outer side of an air outlet of a unit, the blade actuator of the electric louver is connected to a unit main control board of the water chiller, and the opening degree of the louver blade of the electric louver is controlled through the main control board. The water chiller and the control method thereof can greatly reduce the air volume of the system by adjusting the air resistance of the condensing air duct at low temperature, and the fan can maintain the same long-time operation and automatic speed regulation state as the medium-high temperature heating.

Description

Technical Field

[0001] This invention belongs to the field of thermal management technology for energy storage batteries, and particularly relates to an energy storage chiller and its control method for optimizing low-temperature cooling. Background Technology

[0002] During charging and discharging, temperature variations in energy storage batteries affect their efficiency and lifespan. Therefore, developing efficient variable frequency air conditioners (currently, the market primarily uses chillers; the following designs all refer to chiller designs) to address the thermal management needs of energy storage batteries is crucial. Because batteries release a significant amount of heat during operation, a basic requirement for energy storage chillers is that they must maintain cooling functionality even in low-temperature environments. Energy storage chillers have a wide operating range, generally requiring normal operation in ambient temperatures from -40°C to 55°C. To ensure unit capacity under high ambient temperature conditions, typical unit designs involve enlarging the condenser and increasing the condenser fan airflow. However, such configurations are extremely detrimental to cooling under low ambient temperature conditions.

[0003] At extremely low temperatures, the battery's heat dissipation requirements are relatively small, and the compressor frequency of the unit is already low. Even if the fan operates at its lower speed limit, the heat exchange of the condenser is far greater than the required heat dissipation. At this point, to prevent excessively low condensing pressure and compressor liquid return, the fan has to be frequently started and stopped. This operating mode causes rapid, periodic fluctuations in system pressure, which has a very negative impact on compressor lifespan and valve control. However, if the fan is disabled and the system relies entirely on natural condenser cooling, the system faces the risk of frequent overpressure shutdowns. Therefore, a solution is urgently needed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an energy storage chiller and its control method for optimizing low-temperature cooling. The chiller and its control method reduce the system air volume significantly by adjusting the air resistance of the condenser duct at low temperatures, and the fan can maintain the same long-term operation and automatic speed regulation state as in medium and high temperature heating, which can perfectly solve the above problems.

[0005] To achieve the aforementioned objective, the technical solution of the present invention is as follows: an optimized low-temperature refrigeration energy storage chiller and its control method. The device includes an electric louver; the electric louver is installed on the outside of the unit's air outlet, and the blade actuator of the electric louver is connected to the main control board of the chiller, and the opening degree of the louver blades of the electric louver is controlled by the main control board.

[0006] Preferably, it also includes a temperature sensor; the temperature sensor is installed in the chiller and is used to detect the ambient temperature of the condenser; the main control board of the unit controls the opening degree of the louvers of the electric louvers based on the ambient temperature information detected by the temperature sensor.

[0007] Preferably, the control method for an optimized low-temperature cooling energy storage chiller includes the following steps: 1) When the unit detects an ambient temperature T≥0℃, the damper / louver blades maintain the default angle C=90°, i.e., perpendicular to the condenser; 2) When the unit detects -20℃≤ambient temperature T<0℃, the damper / louver blade angle C=(90+n) T)°, the calculation precision is 1°, round down, the initial value of n is 4, and when the calculated value is ≤5°, C=5° is taken; 3) When the unit detects an ambient temperature T < -20℃, the damper / louver blade angle C = (90 + n) 20), the calculation accuracy is 1°, rounded down, the initial value of n is 4, and when the calculated value is ≤5°, C=5° is taken; the fan speed is still automatically adjusted according to the condensing pressure.

[0008] Preferably, step 4) is also included: when the ambient temperature T < 0℃, if the unit's main control board detects that the unit's condensing pressure is higher than 3000 kPa after startup, n = n old -0.5; If the unit reports an overpressure fault and shuts down after startup, n=n old -1; If the unit's condensing pressure drops below 1600 kPa after startup, n=n old +0.5.

[0009] Preferably, it also includes step 5) when the ambient temperature fails, the unit reports an ambient temperature sensor failure, and the damper / louver blades are restored to the default angle C=90°; Preferably, step 6) allows the user to enable the noise reduction mode. After enabling the noise reduction mode, when the unit detects an ambient temperature of 0≤T≤42℃, the unit automatically enters the noise reduction mode, and the air valve / louver blade angle C=45°; when the unit detects an ambient temperature T>45℃, it automatically exits the noise reduction mode, and the air valve / louver blade maintains the default angle C=90°.

[0010] The beneficial effects of this invention are reflected in: The chiller provided by this invention can control the minimum air intake of the unit under low ambient temperature conditions by automatically adjusting the angle of the air valve / fan blades. This avoids the fan starting and stopping, and allows the compressor to operate within a suitable pressure ratio range for extended periods. This improves system stability, increases cooling efficiency, and effectively expands the unit's normal operating range at low temperatures. The control angle has a self-correcting function, automatically correcting the opening when it is determined to be incompatible, thus ensuring compatibility with various model configurations. Simultaneously, the angle adjustment can change the air outlet direction to an upward angle, avoiding the area where people are located, achieving noise reduction under high-temperature conditions and improving user comfort. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the structure of the present invention.

[0012] Explanation of reference numerals in the attached figures: 10. Electric louvers; 11. Louver blades; 12. Blade actuator; 20. Condenser. Detailed Implementation

[0013] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Example 1 like Figure 1 As shown, the present invention provides an energy storage chiller for optimized low-temperature refrigeration and its control method.

[0015] This includes motorized louvers 10 or motorized multi-leaf regulating dampers.

[0016] In practical applications, the electric louver 10 is installed on the outside of the air outlet of the unit, and the blade actuator 12 of the electric louver 10 is electrically connected to the main control board of the chiller unit. The blade actuator 12 is controlled by the main control board, thereby controlling the opening degree of the louver blades 11 of the electric louver 10.

[0017] It also includes a temperature sensor; the temperature sensor is installed in the chiller and is used to detect the ambient temperature of the condenser 20; the main control board of the unit controls the opening degree of the louver blades 11 of the electric louver 10 based on the ambient temperature information detected by the temperature sensor.

[0018] Example 2 A control method for an optimized low-temperature cooling energy storage chiller includes the following steps: 1) When the unit detects an ambient temperature T≥0℃, the louver blades 11 maintain the default angle C=90°; that is, at this time, the louver blades 11 are perpendicular to the condenser, and the fan blows air directly onto them.

[0019] 2) When the unit detects that -20℃ ≤ ambient temperature T < 0℃, the louver blade angle C = (90 + n) T)°, the calculation accuracy is 1°, rounded down, the initial value of n is 4, and when the calculated value is ≤5°, C=5° is taken; the fan speed is automatically adjusted according to the condensing pressure.

[0020] 3) When the unit detects an ambient temperature T < -20℃, the louver blade angle C = (90 + n) 20), the calculation precision is 1°, round down, the initial value of n is 4, and when the calculated value is ≤5°, take C=5°; In practical applications, the fan automatically adjusts according to the condensing pressure: In existing common large units, when a pressure sensor is configured, the fan control is generally controlled according to the condensing pressure.

[0021] For example, within the condensing pressure range of 1800 kPa to 3000 kPa for condenser 20, the fan speed corresponds linearly between 30% and 60% (i.e., 30% for condensing pressure of 1800 kPa, 55% for condensing pressure of 2400 kPa, and so on for specific use settings).

[0022] The angle of the louver blades 11 automatically adjusts with the ambient temperature: when the ambient temperature T = -21℃ is detected, the calculation is performed according to the logic in step 3), and the opening of the louver blades is: C = (90 + n 20)=10°. Since 10° is a small opening, the entire louver blade 11 actually only has one gap for airflow.

[0023] In addition, when the entire system is first started, the compressor operates at a relatively low frequency and the condensing pressure is not high, so the fan only needs to operate at the lower limit speed, for example, 30% of the fan's operating power. However, as the compressor frequency increases, the heat exchange demand of the condenser 20 increases, and the condensing pressure will gradually increase. When the condensing pressure rises to 2000 kPa, since the opening of the louver blades 11 is fixed and adjusted according to the ambient temperature, and the condensing pressure increases, the air volume demand increases. At this time, the fan also needs to increase its speed according to the aforementioned linear correspondence.

[0024] As the fan speed increases and the air volume increases, the system pressure generally stabilizes at a certain value. Only when the pressure continues to rise, exceeding 3000 kPa, will the fan speed also increase to a higher level according to the aforementioned linear correspondence, for example, reaching 60% of the fan's operating power. However, under this condition, the excessively high fan speed affects the system's control operation, indicating that the opening of the louver blades 11 is too small, which does not meet the actual needs, resulting in excessive air resistance and a mismatch with the actual system requirements. Therefore, a new n value is recorded to correct the opening of the louver blades 11, allowing the opening of the louver blades 11 (air valve) to automatically adjust and increase in the next control cycle. This achieves a synergistic adjustment between the fan speed and condensing pressure, and between the opening of the louver blades 11 and the ambient temperature.

[0025] 4) When the ambient temperature T < 0℃, ① if the unit's main control board detects that the unit's condensing pressure is higher than 3000 kPa after startup, n = n old -0.5; ② If the unit reports an overpressure fault and shuts down after startup, n=n old-1; ③ If the unit's condensing pressure drops below 1600 kPa after startup, n=n old +0.5; nold represents the n value before the correction, or the n value of the previous cycle (step).

[0026] In practical applications, for example, if none of the above three situations occur, the value of n will always be the initial value of 4.

[0027] If any of the above three scenarios occur, for example: when scenario ① occurs, the value of n becomes 3.5 and nold becomes 4. A few minutes later, scenario ② occurs, and the value of n becomes 2.5 and nold becomes 3.5, thereby improving the system's flexibility in responding to changes.

[0028] Then situation ③ occurs: Since the pressure is a reference value based on the commonly used refrigerant R410A in energy storage water chillers, different refrigerants should correspond to different pressure values: For example, when the refrigerant of the energy storage chiller is the commonly used refrigerant R134a, the condensing pressure can be referenced as follows: the high value is 1250 and the low value is 600.

[0029] 5) When the ambient temperature fails, the louver blades 11 will restore the default angle C=90°.

[0030] Since the automatic adjustment and control of the louver blades 11 is strongly correlated with the ambient temperature, when the ambient temperature sensor fails, in order to prevent the air valve from malfunctioning and affecting the normal operation of the unit, step 5) can be used to fully open the louver blades 11 (air valve) and restore the low air resistance state. Although the temperature sensor used to test the ambient temperature is relatively stable and generally does not fail, and the entire system adjustment is relatively stable, setting step 5) can further improve the flexibility of the system in response.

[0031] 6) Allow users to enable noise reduction mode. When the unit detects an ambient temperature of 0≤T≤42℃, the unit will automatically enter noise reduction mode and the angle C of the air valve / louver blade 11 will be 45°. When the unit detects an ambient temperature T>45℃, it will automatically exit noise reduction mode and the air valve / louver blade 11 will maintain the default angle C=90°.

[0032] Due to the high energy density and compact installation of energy storage air conditioners, high operating noise is a common pain point in the industry. Common vertical units typically have their air outlets at the top, approximately 1.2-2 meters high, which is right at the user's location and exacerbates perceived noise. However, by adjusting the louvers 11 in step 6), the air outlet angle can be controlled to be angled upwards and away from the user's location in most common operating conditions, optimizing the user's hearing experience and reducing the heat island effect and short-circuiting of the return air.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy storage chiller for optimized low-temperature cooling, characterized in that, Includes an electric louver (10); the electric louver (10) is installed on the outside of the air outlet of the unit, and the blade actuator (12) of the electric louver (10) is electrically connected to the main control board of the chiller, and the opening degree of the louver blade (11) of the electric louver (10) is controlled by the main control board.

2. The energy storage chiller for optimized low-temperature refrigeration according to claim 1, characterized in that, It also includes a temperature sensor; the temperature sensor is installed in the chiller and is used to detect the ambient temperature of the condenser (20); the main control board of the unit controls the opening degree of the louver blades (11) of the electric louver (10) based on the ambient temperature information detected by the temperature sensor.

3. A control method for an optimized low-temperature refrigeration energy storage chiller according to any one of claims 1-2, characterized in that, Includes the following steps: 1) When the unit detects an ambient temperature T≥0℃, the louver blades (11) maintain the default angle C=90°; 2) When the unit detects that -20℃≤ambient temperature T<0℃, the angle C of the louver blade (11) is (90+n) T)°, the calculation precision is 1°, round down, the initial value of n is 4, and when the calculated value is ≤5°, C=5° is taken; 3) When the unit detects an ambient temperature T < -20℃, the angle C of the louver blade (11) is (90 + n) 20), the calculation accuracy is 1°, rounded down, the initial value of n is 4, and when the calculated value is ≤5°, C=5° is taken; the fan speed is still automatically adjusted according to the condensing pressure.

4. The control method for an optimized low-temperature refrigeration energy storage chiller according to claim 3, characterized in that, This also includes step 4) When the ambient temperature T < 0℃, if the unit's main control board detects that the unit's condensing pressure is higher than 3000 kPa after startup, n = n old -0.5; If the unit reports an overpressure fault and shuts down after startup, n=n old -1; If the unit's condensing pressure drops below 1600 kPa after startup, n=n old +0.

5.

5. The control method for an optimized low-temperature refrigeration energy storage chiller according to claim 3, characterized in that, It also includes step 5) when the ambient temperature fails, the louver blades (11) restore the default angle C=90°.

6. The control method for an optimized low-temperature refrigeration energy storage chiller according to claim 3, characterized in that, It also includes step 6) allowing users to enable the noise reduction mode. After enabling the noise reduction mode, when the unit detects an ambient temperature of 0≤T≤42℃, the unit automatically enters the noise reduction mode and the angle of the air valve / louver blade (11) is C=45°; when the unit detects an ambient temperature of T>45℃, it automatically exits the noise reduction mode and the air valve / louver blade (11) maintains the default angle C=90°.

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