Trend judgment constant temperature air conditioning control method

Abstract

This invention discloses a trend-based constant-temperature air conditioning control method, which belongs to the field of constant-temperature air conditioning control. Based on the required temperature of a space, the system divides the space into holding, loading, emergency start, unloading, and emergency stop zones. A loading and unloading cycle is then set for the air conditioner. The number of compressor starts and stops in the air conditioning system is determined based on the temperature changes before and after the loading and unloading cycle, combined with the temperature range within which the space temperature falls. This trend-based constant-temperature air conditioning control method can significantly reduce the frequency of compressor starts and stops in the air conditioning system, thereby extending the compressor's service life.

Description

Technical Field

[0001] The present invention relates to a control method for a constant temperature air conditioner, and in particular to a trend judgment constant temperature air conditioner control method. Background Art

[0002] In spaces that require constant temperature, air conditioning systems are usually used to cool or heat the space so that the temperature of the space fluctuates within the allowable range. The most common solution is to control the temperature of the space by controlling the opening and closing of the air conditioning system compressor. Taking summer cooling as an example, when the space temperature is higher than the upper limit of the space, the air conditioner turns on the compressor to cool the space and the temperature in the room slowly drops; when the temperature in the room is lower than the lower limit of the space temperature, the compressor is turned off, and the space temperature slowly rises due to factors such as the space heating equipment and wall heat conduction until the space temperature reaches the upper limit of the temperature, and then the compressor is turned on to cool and cool, and so on. The disadvantages of this control method are: (1) The temperature fluctuates greatly because it is a start-stop control. The temperature fluctuates back and forth within the upper and lower limits of the set temperature and cannot operate constantly within a small range close to the set temperature; (2) When the compressor starts, the starting current is generally more than 5 times the normal operating current, which causes greater damage to the compressor and electrical control components and increases the failure rate of the unit; (3) When the compressor starts, the vibration is large, and the impact on the multi-split copper pipe is large, which can easily cause pipe and valve rupture, system refrigerant leakage, etc. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art and reduce the start and stop frequency of the compressor in the air-conditioning system, the present invention provides a trend judgment constant temperature air-conditioning control method.

[0004] Technical solution: To achieve the above-mentioned purpose, a trend judgment constant temperature air conditioning control method of the present invention includes the following steps:

[0005] (1) According to the space temperature requirements, the holding area, loading area, unloading area, emergency start area and emergency stop area are divided. Specifically, the space standard temperature requirement is T3°C, the upper limit temperature requirement is T5°C, the lower limit temperature requirement is T1°C, and two other temperature values ​​T2°C and T4°C are taken, and the condition T1°C < T2°C < T3°C < T4°C < T5°C is met. Then the temperature range of the holding area is T2°C ~ T4°C, the temperature range of the loading area is T4°C ~ T5°C, the temperature range of the emergency start area is greater than T5°C, the temperature range of the unloading area is T1°C ~ T2°C, and the temperature range of the emergency stop area is less than T1°C;

[0006] The holding zone is the ideal range for room temperature control and is also the warning zone for temperature changes; the loading zone indicates that the space temperature has exceeded the upper warning line of temperature control and the load of the compressor needs to be increased; when the space temperature reaches the emergency start zone, it means that the space temperature has reached the upper limit of the control target and all compressors need to be urgently put into cooling. At this time, it is not restricted by the loading and unloading cycles, and the air-conditioning system immediately starts all compressors for cooling; when the space temperature is in the unloading zone, it means that the space temperature has dropped to the lower warning line of temperature control and the load of the compressor needs to be reduced; when the space temperature reaches the emergency stop zone, it means that the space temperature has reached the lower limit of the control target and the compressor cooling needs to be urgently stopped. At this time, it is not restricted by the loading and unloading cycles and the air-conditioning system immediately stops the operation of all compressors.

[0007] (2) Set a loading and unloading cycle for the air conditioning system of the space. That is, every loading and unloading cycle, a judgment is made on whether to start, stop, or keep the compressor. Within the same loading and unloading cycle, the number of operating compressors in the air conditioning system remains unchanged. The temperature at the beginning of the loading and unloading cycle is Ti1°C, and the temperature at the end of the loading and unloading cycle is Ti2°C. The temperature change value is ΔT°C, then ΔT = Ti1-Ti2.

[0008] When ΔT is a positive value, it means that the space temperature tends to decrease during this loading and unloading cycle; the larger the value, the more the air conditioning load exceeds the actual demand load.

[0009] When ΔT is a negative value, it means that the space temperature tends to rise during this loading and unloading cycle; the larger the value, the more the air conditioning load is less than the actual demand load;

[0010] When ΔT is 0, it means that the space temperature does not change during this loading and unloading cycle; this means that the air conditioning load and the actual load are equal and the system is in a balanced state.

[0011] (3) According to the space temperature and ΔT value, determine whether to increase or decrease the number of compressors in the air conditioning system. Specifically,

[0012] At the end of a loading and unloading cycle, the space temperature is in the loading zone. At the same time, if ΔT>0, it means that the room has established a cooling trend at this time, and there is no need to increase the number of running compressors; if ΔT<0, it means that the room is still in a heating state, and the number of running compressors needs to be increased; if ΔT=0, it means that the temperature is in a balanced state at this time, and there is no need to increase or decrease the number of running compressors.

[0013] At the end of a loading and unloading cycle, the space temperature is in the unloading zone. At the same time, if ΔT>0, it means that the room is still maintaining a cooling trend, and it is necessary to reduce the number of running compressors to change this trend of continued temperature decline; if ΔT<0, it means that the room is already in a heating state, and there is no need to increase the number of running compressors; if ΔT=0, it means that the temperature is in a balanced state, and there is no need to increase or decrease the number of running compressors.

[0014] At the end of a loading and unloading cycle, if the space temperature is in the holding zone, there is no need to consider the size of ΔT and there is no need to increase or decrease the number of compressors in operation.

[0015] Furthermore, the air-conditioning system has at least two compressors, and the start and stop order of the at least two compressors in the air-conditioning system is based on the principle of first-on-first-off, and the compressors are started and stopped in sequence.

[0016] Furthermore, in step (1), T2 = T1 + 1 / 2 (T3 - T1) = 1 / 2 (T3 + T1), T4 = T3 + 1 / 2 (T5 - T3) = 1 / 2 (T3 + T5).

[0017] Beneficial effect: A trend judgment constant temperature air conditioning control method of the present invention finds the balance point between the space load and the air conditioning load by judging the trend of space temperature changes, and then determines the number of compressor starts, so that the room temperature tends to be constant, achieving the technical effect of significantly reducing the start and stop frequency of the compressor and extending the service life of the air conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the principle of dividing the holding area, loading area, emergency start area, unloading area, and emergency stop area in the present invention. DETAILED DESCRIPTION

[0019] The following combination Figure 1 The principles and features of the present invention are described, and the examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0020] A trend judgment constant temperature air conditioning control method includes the following steps:

[0021] (1) In this embodiment, the required temperature of the space is 26°C, i.e., T3. The air-conditioning system is in cooling mode. The upper limit temperature required by the space is 30°C, i.e., T5. The lower limit temperature required by the space is 22°C, i.e., T1. Another temperature is 24°C, i.e., T2, and the temperature is 28°C, i.e., T4. Based on this, the temperature range of the holding zone is 24°C to 28°C, the temperature range of the loading zone is 28°C to 30°C, the temperature range of the emergency start zone is greater than 30°C, the temperature range of the unloading zone is 22°C to 24°C, and the temperature range of the emergency stop zone is less than 22°C.

[0022] (2) There are five compressors in the air-conditioning system. A loading and unloading cycle of 3 minutes is set for the air-conditioning system of the space. In the same loading and unloading cycle, the number of operating compressors in the air-conditioning system is kept unchanged. The temperature at the beginning of the loading and unloading cycle is Ti1°C, and the temperature at the end of the loading and unloading cycle is Ti2°C. The temperature change value is ΔT°C, then ΔT = Ti1-Ti2.

[0023] (3) According to the indoor temperature and the ΔT value, determine whether to increase or decrease the number of compressors in the air conditioning system. Specifically,

[0024] When the indoor temperature is monitored to be between 28°C and 30°C, if ΔT>0, it means that the room has established a cooling trend and there is no need to increase the number of running compressors; if ΔT<0, it means that the temperature is in a rising state and the number of running compressors needs to be increased; if ΔT=0, there is no need to increase or decrease the number of running compressors.

[0025] When the indoor temperature is monitored to be between 22°C and 24°C, if ΔT>0, it means that the room is still cooling down, and the number of running compressors needs to be reduced; if ΔT<0, it means that the room is already heating up, and there is no need to increase the number of running compressors; if ΔT=0, there is no need to increase or decrease the number of running compressors;

[0026] When the indoor temperature is monitored to be between 24°C and 28°C, there is no need to consider the size of ΔT and there is no need to increase or decrease the number of compressor operations.

[0027] When the monitored temperature is greater than 30°C, all compressors need to be started regardless of the size of ΔT.

[0028] When the monitored temperature is less than 22°C, all compressors need to be stopped regardless of the size of ΔT.

[0029] It is worth noting that when starting or shutting down the compressor, the start and stop sequence should be based on the principle of first start first stop.

[0030] 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 in the scope of protection of the present invention.

Claims

1. A trend judgment constant temperature air conditioning control method, characterized in that: The following steps are involved: (1) According to the space temperature requirements, the holding area, loading area, unloading area, emergency start area and emergency stop area are divided. Specifically, the space standard temperature requirement is T3°C, the upper limit temperature requirement is T5°C, the lower limit temperature requirement is T1°C, and two other temperature values ​​T2°C and T4°C are taken, and the condition T1°C < T2°C < T3°C < T4°C < T5°C is met. Then the temperature range of the holding area is T2°C ~ T4°C, the temperature range of the loading area is T4°C ~ T5°C, the temperature range of the emergency start area is greater than T5°C, the temperature range of the unloading area is T1°C ~ T2°C, and the temperature range of the emergency stop area is less than T1°C; (2) Setting a loading and unloading cycle for the air conditioning system of the space. Within the same loading and unloading cycle, the number of operating compressors in the air conditioning system remains unchanged. The temperature at the beginning of the loading and unloading cycle is Ti1°C, and the temperature at the end of the loading and unloading cycle is Ti2°C. The temperature change value is ΔT°C, then ΔT = Ti1-Ti2; Among them, when ΔT is a positive value, it means that the space temperature has a downward trend during this loading and unloading cycle; the larger the value, the more the air conditioning load exceeds the actual demand load; When ΔT is a negative value, it means that the space temperature tends to rise during this loading and unloading cycle; the larger the value, the more the air conditioning load is less than the actual demand load; When ΔT is 0, it means that the space temperature does not change during this loading and unloading cycle; this means that the air conditioning load and the actual load are equal and the system is in a balanced state; (3) According to the indoor temperature and the ΔT value, determine whether to increase or decrease the number of compressors in the air conditioning system. Specifically, The indoor temperature is in the loading zone. If ΔT>0, there is no need to increase the number of running compressors; if ΔT<0, there is a need to increase the number of running compressors; if ΔT=0, there is no need to increase or decrease the number of running compressors; The indoor temperature is in the unloading zone. At the same time, if ΔT>0, the number of running compressors needs to be reduced; if ΔT<0, the number of running compressors does not need to be increased; if ΔT=0, the number of running compressors does not need to be increased or decreased; If the indoor temperature is in the holding zone, there is no need to consider the size of ΔT and there is no need to increase or decrease the number of compressors running; If the indoor temperature is in the emergency start zone, all compressors need to be started without considering the size of ΔT. If the indoor temperature is in the emergency stop zone, all compressors need to be stopped regardless of the size of ΔT.

2. The trend judgment constant temperature air conditioning control method according to claim 1, characterized in that: The air-conditioning system comprises at least two compressors, and the start and stop order of the at least two compressors in the air-conditioning system is based on the principle of first-on-first-off, and the compressors are started and stopped in sequence.

3. The trend judgment constant temperature air conditioning control method according to claim 1, characterized in that: In the step (1), T2=T1+1 / 2(T3-T1)=1 / 2(T3+T1), T4=T3+1 / 2(T5-T3)=1 / 2(T3+T5).

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