CN105737419B - Active dynamic cooling control device and method - Google Patents

Abstract

The invention provides an active dynamic cooling control device and method, wherein the device comprises a refrigeration basic unit, a control unit and a cooling space; wherein: a closed loop formed by sequentially connecting the compressor, the condenser and the evaporator is a refrigeration basic unit; the cooled object and the evaporator are both arranged in the cooling space; the control unit comprises a controller and a control valve; wherein: the control valve is arranged between the condenser and the evaporator, and the output cold quantity of the compressor is adjusted by changing the opening degree of the control valve; and the controller sends an adjusting instruction to the control valve according to the stored performance parameters and the real-time acquired operation parameters, so that the dynamic balance between the output cold quantity of the compressor and the heat exchange quantity of the cooled object in the refrigeration process is realized. The invention realizes active refrigeration by keeping the output cold quantity of the compressor to be the same as the heat exchange quantity of the cooled object in real time.

Description

An active dynamic cooling control device and method

technical field

The invention relates to the field of temperature preservation, in particular to an active dynamic cooling control device and method.

Background technique

Air-conditioning and refrigeration devices have been widely used in quick-freezing and fresh-keeping technology, beverage quick-cooling technology and other fields that need to cool down the object to be cooled. Rapid cooling is the main purpose of air-conditioning and refrigeration devices, so the cooling speed of the object to be cooled becomes a key process technical indicator. Existing air conditioners or refrigeration devices generally adjust the flow of refrigerant in the refrigeration system through throttling elements such as capillary tubes and thermal expansion valves. Refrigeration cycle parameters such as temperature are used as input parameters, and the corresponding changes in the heat load of the object to be cooled are matched by passively adjusting the flow rate and evaporation temperature of the refrigerant to achieve the cooling of the object to be cooled. It can be seen that the heat transfer (cold) process of cooling the object to be cooled is as follows: the refrigerant evaporates and absorbs heat to reduce the wall temperature of the evaporator → the evaporator transfers the cooling capacity to the air through convective heat transfer → the air transfers the cooling capacity through convective heat transfer Passed to the cooled object.

After the refrigeration system is determined, its convective heat transfer coefficient is basically fixed. If the heat transfer is limited by the convective heat transfer coefficient (that is, the air side is limited), the way to increase the heat transfer is to increase the heat transfer temperature difference. In this way, in order to achieve the fastest cooling rate during the cooling process, it is necessary to maintain the maximum heat transfer temperature difference between the refrigerant and the object to be cooled (even if the evaporation temperature of the refrigeration cycle is always kept at the lowest). In the refrigeration cycle with the thermal expansion valve as the throttling element, the evaporation temperature of the refrigerant will gradually decrease as the temperature of the object to be cooled decreases during the cooling and adjustment process of the cargo. The heat transfer temperature difference becomes smaller, which affects the cooling speed of the cargo.

In air-conditioning or refrigeration devices using capillary tubes as throttling elements, especially when the cooled object has a large cooling range, the capillary tube has limited ability to adjust the refrigerant flow rate and evaporation temperature in the refrigeration cycle; and the heat transfer during the cooling process is affected by The refrigerating capacity of the unit is not limited by the heat transfer temperature difference. At this time, if the evaporating temperature cannot be reduced with the decrease of the temperature of the cooled object due to the limited adjustment range of the throttling device, the output cooling capacity of the unit cannot be maximized, resulting in Cooled objects cool down more slowly.

Contents of the invention

In view of this, the present invention provides an active dynamic cooling control device and method, aiming at realizing the fastest and reliable cooling of the object to be cooled.

The technical scheme adopted in the present invention is specifically:

An active dynamic cooling control device, including a basic refrigeration unit, a control unit and a cooling space; wherein:

The closed loop formed by the compressor, condenser and evaporator connected in sequence is the basic unit of refrigeration;

Both the object to be cooled and the evaporator are placed in the cooling space;

The control unit includes a controller and a control valve; wherein:

The control valve is arranged between the condenser and the evaporator, and the output cooling capacity of the compressor is adjusted by changing its opening;

The controller issues adjustment instructions to the control valve according to the stored performance parameters and the real-time collected operating parameters, so as to realize the dynamic balance between the cooling capacity output by the compressor and the heat transfer capacity of the object to be cooled during the refrigeration process.

In the above-mentioned active dynamic cooling control device, the input end of the controller is respectively connected with the compressor, the temperature sensor group, and the evaporator fan for collecting operating parameters; the output end is connected with the control valve for The valve opening of the control valve is adjusted according to the collected operating parameters and pre-stored performance parameters.

In the above-mentioned active dynamic cooling control device, the temperature sensor group includes a first temperature sensor and a second sensor, which are respectively used to collect the supply air temperature and the return air temperature of the evaporator.

In the above active dynamic cooling control device, the pre-stored performance parameters include compressor performance parameters and evaporator fan performance parameters; wherein:

The compressor performance parameter is the compressor performance curve, which is the relationship curve between the cooling capacity of the compressor and the operating parameters. The operating parameters include evaporation temperature, condensation temperature, suction and discharge pressure, and the relationship curve between input power and suction pressure;

The performance parameter of the evaporator fan is the relationship between the fan speed and the mass flow rate.

An active dynamic cooling control method, specifically comprising the following steps:

Heat transfer step: the refrigerant in the evaporator evaporates and absorbs heat to reduce the temperature of the wall surface of the evaporator, and transfers the cold energy obtained by the temperature reduction through convective heat exchange to the air in the cooling space and then to the object to be cooled;

Adjustment step: During the process of the heat transfer step, the controller adjusts the opening of the control valve according to the stored performance parameters of the compressor and evaporator, combined with the operating parameters collected in real time, to realize the output cooling capacity of the compressor during the refrigeration process. The dynamic balance of heat exchange with the cooled object until the temperature of the cooled object reaches the set level.

In the above-mentioned active dynamic cooling control method, the output cooling capacity of the compressor is the heat exchange Q _a1 =kA(T _o -T _e ) from the refrigerant in the evaporator to the object to be cooled;

In the above formula:

A is the heat exchange area of the cooled object;

T _o is the temperature of the cooled object;

T _e is the evaporation temperature of the refrigerant;

k is the heat transfer coefficient between the refrigerant and the cooled object;

In the above formula:

h ₁ is the convective heat transfer coefficient between the refrigerant and the wall;

δ is the wall thickness of the evaporator;

λ is the thermal conductivity of the evaporator wall;

h2 is the heat transfer coefficient between the evaporator wall and air _;

h ₃ is the heat transfer coefficient between the air and the object to be cooled;

The heat transfer of the object to be cooled is the heat transfer amount of the object to be cooled sent by the cold air of the evaporator Q _a2 =cm(T _in -T _out );

In the above formula:

c is the specific heat of air;

m is the air mass flow rate;

T _in is the return air temperature of the evaporator;

T _out is the air supply temperature of the evaporator.

The controller monitors the relationship between the output cooling capacity of the compressor and the heat transfer capacity of the object to be cooled in real time, and analyzes whether the heat transfer limits the cooling capacity transfer or the cooling capacity of the compressor limits the cooling capacity transfer. Further, through the controller Make the output cooling capacity of the compressor dynamically equal to the heat transfer capacity of the object to be cooled until the object to be cooled reaches the set temperature.

In the above-mentioned active dynamic cooling control method, when the heat transfer between the refrigerant and the object to be cooled is limited by the output cooling capacity of the compressor, the control valve maintains the maximum opening, so that the compressor outputs the maximum cooling capacity, and the cooling rate of the object to be cooled fastest.

In the above-mentioned active dynamic cooling control method, when the heat transfer between the refrigerant and the cooled object is limited by the convective heat transfer coefficient, the control valve maintains the minimum opening, so that the evaporation temperature and the cooled object maintain the maximum heat transfer temperature difference, so that the cooled object Cooling objects cool down the fastest.

The beneficial effects produced by the present invention are:

The active dynamic cooling control method of the present invention takes the operating parameters of the refrigerating compressor of the refrigeration unit, the operating parameters of the evaporator fan, and the temperature of the evaporator return air as the main basis, and uses the adjustment of the control valve as the main means to match the cooling capacity output by the compressor. The amount of heat exchange with the object to be cooled enables the maximum amount of heat exchange between the object to be cooled and the refrigerant to quickly cool down the object to be cooled.

Description of drawings

The present invention may be more fully and better understood when considered in conjunction with the accompanying drawings. The drawings described here are used to provide a further understanding of the present invention, and the embodiments and their descriptions are used to explain the present invention, and do not constitute improper limitations to the present invention.

Fig. 1 is a structural schematic diagram of an active dynamic cooling control device of the present invention;

Fig. 2 is a relationship diagram 1 of the cooling capacity of the compressor of the active dynamic cooling control device of the present invention and the heat transfer capacity of the object to be cooled;

Fig. 3 is the relationship between the cooling capacity of the compressor of an active dynamic cooling control device of the present invention and the heat transfer rate of the object to be cooled (under the condition of being limited by the heat transfer coefficient);

Fig. 4 is a diagram 3 of the relationship between the cooling capacity of the compressor and the heat transfer rate of the object to be cooled in an active dynamic cooling control device according to the present invention (under the condition of being limited by the cooling capacity of the compressor).

In the picture:

1. Compressor 2. Condenser 3. Control valve 4. Evaporator 5. Controller 6. Evaporator fan 7. Cooling space 8. Supply air temperature sensor 9. Return air temperature sensor 10. Object to be cooled.

detailed description

The technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

An active dynamic cooling control device as shown in Figure 1 mainly includes a compressor 1, a condenser 2, a control valve 3, an evaporator 4 and a controller 5; wherein:

Compressor 1, condenser 2 and evaporator 4 are connected in sequence to form a closed loop as the basic unit of refrigeration;

The evaporator 4 and the cooled object 10 are placed in the cooling space 7;

The input end of the controller 5 is respectively connected with the compressor 1 and the supply air temperature sensor 8 for collecting the temperature parameters of the evaporator 4, the return air temperature sensor 9, and the evaporator fan 6, and the output end is connected with the condenser 2 and the evaporator fan 6. The control valve 3 between 4 is connected to each other, and the opening degree of the control valve is adjusted to ensure that the cooling capacity output by the compressor is dynamically the same as the heat transfer capacity of the cooled object during the refrigeration process.

Above-mentioned device realizes that the cooling process to cooled object 10 is specifically as follows:

The controller 5 performs cooling and cooling on the object 10 to be cooled according to the collected operating parameters of the compressor 1 and the evaporator fan 6 and the stored data including the performance parameters of the compressor 1 and the evaporator fan 6 . Among them, the performance parameters of the compressor are the performance curves of the compressor, that is, the relationship between the cooling capacity of the compressor and various relevant operating parameters; such as: the relationship curve between the cooling capacity of the compressor and the evaporating temperature/condensing temperature, suction and exhaust pressure, and input power; Performance parameters refer to the relationship between fan speed and mass flow. specifically:

The refrigerant in the evaporator 4 evaporates and absorbs heat to reduce the temperature of the wall surface of the evaporator 4. Through convective heat exchange, the cold energy obtained by the temperature reduction is transferred to the air in the cooling space 7, and the air is further transferred to the air in the cooling space 7 through convective heat exchange. The cold energy obtained is transferred to the cooled object 10 (such as fresh food).

The specific heat transfer process equation is:

The amount of heat exchange between the refrigerant and the cooled object Q _a1 ＝kA(T _o -T _e )

In the above formula:

A is the heat exchange area (cooled object 10);

T _o is the temperature of the cooled object;

T _e is the evaporation temperature of the refrigerant;

k is the heat transfer coefficient between the refrigerant and the cooled object;

In the above formula:

h ₁ is the convective heat transfer coefficient between the refrigerant and the wall;

δ is the wall thickness of the evaporator;

λ is the thermal conductivity of the evaporator wall;

h2 is the heat transfer coefficient between the evaporator wall and air _;

h ₃ is the heat transfer coefficient between the air and the object to be cooled.

After the refrigeration system is determined, A, (δ, λ, h ₁ , h ₂ , h ₃ ) in the above parameters and the determined k can be considered as constants, that is to say, the relationship between the refrigerant and the cooled object 10 The heat transfer Q _a takes temperature as the main variation, that is, Q _a = f(T _e , T _o ). As shown in Figure 2, assuming that the temperature of the cooling object T ₁ =T _o >T ₂ >T ₃ >T ₄ >T ₅ , it can be seen that when the temperature of the cooling object is given, Q _a increases with the refrigerant evaporation temperature T _e Decreases with the increase of , and it is a linear relationship. Under different cooled object temperatures, the relationship curve between Q _a and T _e is a straight line with a negative slope.

At the same time, since the heat exchange of the object to be cooled 10 is sent through the cold air of the evaporator 4, therefore:

Q _a2 ＝cm(T _in -T _out )

In the above formula:

c is the specific heat of air;

m is the air mass flow rate;

T _in is the return air temperature of the evaporator;

T _out is the air supply temperature of the evaporator.

The compressor cooling capacity Q _c is related to the refrigerant evaporation temperature T _e and the refrigerant condensation temperature T _c , and when a refrigeration system is determined, T _c is basically unchanged, that is to say, the compressor cooling capacity Q _c is determined by the refrigerant evaporation temperature The temperature T _e is the main variation, that is, Q _c =f(T _e ). The curve also refers to Figure 2. It can be seen that the cooling capacity Q _c of the compressor increases with the increase of the refrigerant evaporation temperature T _e .

Q _a1 ＝kA(T _o -T _e ) is a classic formula of heat transfer, which is to obtain the amount of heat exchange between the refrigerant and the object to be cooled from the perspective of heat transfer, and Q _a2 ＝cm(T _in -T _out ) is The amount of cooling that the air receives from the evaporator is obtained from the point of view of the air. If the system reaches a steady state, these two values are equal. But because the cooling process of the cooled object is a dynamic process, the two are not equal. The present invention utilizes the unequal of these two values to analyze whether the heat transfer limits the cooling transfer or the cooling capacity of the compressor limits the cooling transfer, so as to realize the control of the fastest cooling rate.

。When the refrigeration system is turned on, the refrigerant evaporation temperature T _e is higher, which is set as T _e,1 , and the cooling capacity of the compressor at this time is Q _c,1 , and the heat exchange between the refrigerant and the object to be cooled is

.

；具体公式为

，其中m为空气的质量流量，蒸发器风机6的转速参数实时传回到控制器5，控制器5根据其内已存储的风机转速与质量流量的关系，则可得出风机送风的质量流量，即由蒸发器风机6的运行参数与控制器5内存储的性能参数比对后即可得出；The controller 5 detects the evaporator supply air temperature T _in and the evaporator return air temperature T _out through the air supply temperature sensor 8 and the return air temperature sensor 9 respectively, and calculates the evaporator fan 6 combined with the real-time running data of the evaporator fan 6. Cooling object heat transfer

; The specific formula is

, where m is the mass flow rate of the air, the speed parameter of the evaporator fan 6 is sent back to the controller 5 in real time, and the controller 5 can obtain the quality of the air supplied by the fan according to the relationship between the fan speed and the mass flow rate stored in it. The flow rate can be obtained after comparing the operating parameters of the evaporator fan 6 with the performance parameters stored in the controller 5;

Simultaneously, the real-time operation data of the compressor is also transmitted back to the controller 5, and the controller 5 calculates the compressor cooling capacity Qc _{, 1} by comparing it with the pre-stored compressor performance data; the compressor 1 will operate in real time The parameters are returned to the controller 5, and compared with the corresponding compressor performance curve stored in the controller 5, the cooling capacity of the compressor 1 can be obtained.

，控制器5即发出调小控制阀3开度的指令，将制冷剂蒸发温度降低到T_e，2，使压缩机输出冷量与被冷却对象换热量相同；Since Q _{c at this time, 1} is greater than

, the controller 5 issues an instruction to reduce the opening of the control valve 3 to reduce the refrigerant evaporation temperature to T _{e, 2} , so that the output cooling capacity of the compressor is the same as the heat transfer capacity of the cooled object;

Afterwards, the object to be cooled will continue to cool down. When the temperature drops to T ₂ , if the refrigeration unit still operates according to T _{e, 2} , the output cooling capacity of the compressor is greater than the heat transfer of the object to be cooled. Similar to the above adjustment process, it needs to be reduced The opening of the valve reduces the evaporating temperature to T _{e, 3} , so that the output cooling capacity of the compressor is the same as the heat transfer capacity of the cooled object.

That is, it is necessary to monitor the relationship between the heat transfer amount of the object to be cooled and the output cooling capacity of the compressor in real time. Through the control of the controller 5, the output cooling capacity of the compressor is equal to the heat transfer amount of the object to be cooled until the object to be cooled 10 reaches the set temperature T ₅ , corresponding to the refrigerant evaporation temperature T _e,5 .

When a new cooling object 10 is added during the period, the average temperature of the cooling object 10 rises to T ₄ , at this time, the refrigerator 5 adjusts the valve opening of the control valve 3 to make it still at the temperature where the refrigerant evaporation temperature is With an opening degree of T _e,5 , the output cooling capacity of the refrigeration system is less than the possible heat transfer capacity of the cooled object;

(图2中9点)。然后根据被冷却对象温度变化，继续调节降温过程。The controller 5 adjusts the opening of the control valve 3 to increase the evaporation temperature to T _e,6 by calculating and comparing the relationship between the heat transfer of the object to be cooled and the output cooling capacity of the compressor, so that the output cooling capacity of the compressor is Q _{c , 4} (point 9 in Figure 2) is equal to the heat exchange rate of the cooled object

(9 points in Figure 2). Then, according to the temperature change of the cooled object, continue to adjust the cooling process.

In addition, the cooling control device of the present invention can also be used to achieve the fastest cooling speed and two special treatment conditions for increasing heat transfer:

1. After the refrigeration system is determined, since the convective heat transfer coefficient is basically fixed and the heat transfer is limited by the convective heat transfer coefficient (air side), the only way to increase the heat transfer is to increase the heat transfer temperature difference. Therefore, in the cooling process, to achieve the fastest cooling speed, the evaporation temperature of the refrigeration cycle can be kept at the lowest, that is, to maintain the maximum heat exchange temperature difference between the refrigerant and the cooled object. Refer to Figure 3 for the specific implementation process:

。控制器5通过送风温度传感器8和回风温度传感器9检测蒸发器送风温度T_in和蒸发器回风温度T_out，并通过实时传回的蒸发器风机6的运行数据计算出被冷却对象换热量

。压缩机的实时运行数据也传回控制器，控制器通过比对压缩机的实时运行数据以及存储的性能数据，计算出压缩机制冷量Q_c，1。由于此时压缩机的制冷量Q_c，1大于与被冷却对象的最大换热量为

控制器5即发出调小控制阀3开度的控制指令。当阀门开度调节到最小时，蒸发温度T_e,2下压缩机输出冷量大于被冷却对象可能换热量，机组维持最低蒸发温度T_e,2。被冷却对象温度降低到模板温度T₂，此时，压缩机输出冷量Q_c，2仍然大于被冷却对象换热量。此降温过程中，控制阀开度始终保持最小开度，以保持蒸发温度与被冷却对象的最大温差，从而实现对被冷却对象10的快速降温。When the refrigeration system is turned on, the evaporating temperature is set to T _e,1 , and the cooling capacity of the compressor is Q _c,1 , at this evaporating temperature, the heat exchange between the refrigerant and the cooled object is

. The controller 5 detects the supply air temperature T _in of the evaporator and the return air temperature T _out of the evaporator through the air supply temperature sensor 8 and the return air temperature sensor 9 , and calculates the temperature of the cooled object through the operation data of the evaporator fan 6 sent back in real time. heat exchange

. The real-time operation data of the compressor is also sent back to the controller, and the controller calculates the cooling capacity Q _c,1 of the compressor by comparing the real-time operation data of the compressor with the stored performance data. Since the cooling capacity Q _{c of the compressor at this time, 1} is greater than the maximum heat exchange with the cooled object is

The controller 5 promptly sends out a control command to turn down the opening of the control valve 3 . When the valve opening is adjusted to the minimum, the output cooling capacity of the compressor at the evaporation temperature T _e,2 is greater than the possible heat transfer of the cooled object, and the unit maintains the minimum evaporation temperature T _e,2 . The temperature of the object to be cooled is lowered to the template temperature T ₂ , at this time, the output cooling capacity Q _{c, 2} of the compressor is still greater than the heat transfer amount of the object to be cooled. During this cooling process, the opening of the control valve is always kept at the minimum opening, so as to maintain the maximum temperature difference between the evaporation temperature and the object to be cooled, so as to realize rapid cooling of the object to be cooled 10 .

The cooling capacity is adjusted based on the operating parameters of the compressor, the temperature of the supply air and return air of the evaporator, and the operating parameters of the fan of the evaporator. Making full use of the existing compressor performance data and evaporator fan performance data, it is possible to realize the dynamic operation adjustment of refrigeration conditions without complicated testing methods;

By dynamically matching the refrigerating capacity output by the compressor 1 with the heat transfer capacity of the cooled object 10, the cooling speed of the cooled object 10 is maximized; The amount of heat exchange between the agent and the object to be cooled 10 reaches the maximum, and the object to be cooled 10 realizes the fastest cooling speed.

That is: when the heat transfer between the refrigerant and the object to be cooled is limited by the convective heat transfer coefficient, the control valve maintains the minimum opening, so that the evaporation temperature and the object to be cooled maintain the maximum heat transfer temperature difference, so that the object to be cooled can cool down the fastest.

2. After the refrigeration system is determined, the convective heat transfer coefficient is basically fixed and large enough, and the heat transfer is limited by the output power of the compressor. The way to increase heat transfer is to maximize the output power of the compressor. Therefore, in the cooling process, it is necessary to achieve the fastest cooling speed, even if the evaporation temperature of the refrigeration cycle remains the highest possible, and maintain the minimum heat exchange temperature difference between the refrigerant and the object to be cooled. Refer to Figure 4 for the specific implementation process:

。控制器(5)通过送风温度传感器8和回风温度传感器9检测蒸发器送风温度T_in和蒸发器回风温度T_out，并通过实时送回的蒸发器风机6的运行数据计算出被冷却对象换热量

。压缩机实时运行数据也传回控制器，控制器与输入的压缩机性能数据比对，计算出压缩机制冷量Q_c，1。此时，压缩机的制冷量Q_c，1小于与被冷却对象的最大换热量为

。控制器5发出调大控制阀3开度的控制指令。但是当阀门开度调节到最大时，蒸发温度为T_e,2，在此蒸发温度下压缩机输出冷量仍然小于被冷却对象可能换热量，机组维持最高蒸发温度T_e,2。被冷却对象温度降低到目标温度T₂，此时，压缩机输出冷量Q_c，2仍然小于被冷却对象换热量。此降温过程中，控制阀开度始终保持最大开度，以保持压缩机输出最大冷量。When the refrigeration system is turned on, the evaporating temperature is set to T _e,1 , and the cooling capacity of the compressor is Q _c,1 , at this evaporating temperature, the heat exchange between the refrigerant and the cooled object is

. The controller (5) detects the supply air temperature T _in of the evaporator and the return air temperature T _out of the evaporator through the air supply temperature sensor 8 and the return air temperature sensor 9, and calculates the evaporator fan 6 based on the operating data sent back in real time. Cooling object heat transfer

. The real-time operating data of the compressor is also sent back to the controller, and the controller compares it with the input compressor performance data to calculate the compressor cooling capacity Q _c,1 . At this time, the cooling capacity of the compressor Q _c,1 is less than the maximum heat exchange with the cooled object is

. The controller 5 issues a control command to increase the opening of the control valve 3 . But when the valve opening is adjusted to the maximum, the evaporating temperature is T _e,2 . At this evaporating temperature, the output cooling capacity of the compressor is still less than the possible heat transfer of the cooled object, and the unit maintains the highest evaporating temperature T _e,2 . The temperature of the object to be cooled is lowered to the target temperature T ₂ , at this time, the output cooling capacity Q _{c, 2} of the compressor is still smaller than the heat transfer amount of the object to be cooled. During this cooling process, the opening of the control valve is always kept at the maximum opening to maintain the maximum cooling capacity of the compressor.

That is: when the heat transfer between the refrigerant and the object to be cooled is limited by the output cooling capacity of the compressor, the control valve maintains the maximum opening, so that the compressor outputs the maximum cooling capacity and the object to be cooled cools down the fastest.

The present invention realizes the active cooling of the object to be cooled by the refrigeration system through the controller. The evaporator air supply and return air temperature, the evaporator fan operating parameters and the compressor operating parameters are the main basis, and the cooling capacity is adjusted through the control valve. Dynamically realize the matching of the cooling capacity of the compressor and the heat transfer capacity of the cooled object.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, and the accompanying drawings here are used to provide further understanding of the present invention. Obviously, the above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any changes that can be easily conceived by those skilled in the art and do not substantially depart from the present invention Or replace, also all be included in the scope of protection of the present invention.

Claims (7)

1. An active dynamic cooling control device is characterized by comprising a refrigeration basic unit, a control unit and a cooling space; wherein:

a closed loop formed by sequentially connecting the compressor, the condenser and the evaporator is a refrigeration basic unit;

the cooled object and the evaporator are both arranged in the cooling space;

the control unit comprises a controller and a control valve; wherein:

the control valve is arranged between the condenser and the evaporator, and the output cold quantity of the compressor is adjusted by changing the opening degree of the control valve;

the controller sends an adjusting instruction to the control valve according to the stored performance parameters and the real-time acquired operation parameters, so that the dynamic balance between the output cold quantity of the compressor and the heat exchange quantity of the cooled object in the refrigeration process is realized;

the output cold energy of the compressor is the heat exchange quantity Q from the refrigerant of the evaporator to the cooled object _a1 ＝kA(T _o -T _e ) (ii) a In the above formula:

a is the heat exchange area of the cooled object;

T _o is the temperature of the cooled object;

T _e is the refrigerant evaporation temperature;

k is the heat exchange coefficient between the refrigerant and the cooled object;

in the above formula:

h ₁ the heat convection coefficient between the refrigerant and the wall surface;

delta is the evaporator wall thickness;

lambda is the heat conduction coefficient of the wall surface of the evaporator;

h ₂ the heat exchange coefficient between the wall surface of the evaporator and the air is taken as the heat exchange coefficient;

h ₃ the heat exchange coefficient of the air and the cooled object;

the heat exchange amount of the object to be cooled, i.e., the heat exchange amount Q of the object to be cooled fed from the cold air of the evaporator _a2 ＝cm(T _in -T _out ) (ii) a In the above formula:

c is the specific heat of air;

m is the air mass flow;

T _in the return air temperature of the evaporator;

T _out supplying air to the evaporator;

the controller analyzes and obtains the conclusion that the heat exchange limits the cold quantity transmission or the compressor refrigerating quantity limits the cold quantity transmission by monitoring the relation between the cold quantity output by the compressor and the heat exchange quantity of the cooled object in real time, and further enables the cold quantity output by the compressor and the heat exchange quantity of the cooled object to be dynamically equal through the controller until the cooled object reaches the set temperature.

2. The active dynamic cooling control device according to claim 1, wherein an input end of the controller is connected to the compressor, the temperature sensor group, and the evaporator fan, respectively, for acquiring operation parameters; the output end is connected with the control valve and used for adjusting the valve opening of the control valve according to the collected operation parameters and the pre-stored performance parameters.

3. The active dynamic cooling control device of claim 2, wherein the set of temperature sensors comprises a first temperature sensor and a second temperature sensor for respectively acquiring a supply air temperature and a return air temperature of the evaporator.

4. The active dynamic cooling control device of claim 2, wherein the pre-stored performance parameters include compressor performance parameters and evaporator fan performance parameters; wherein:

the performance parameters of the compressor are a performance curve of the compressor and a relation curve between the refrigerating capacity of the compressor and the operation parameters, and the operation parameters comprise evaporation temperature, condensation temperature, suction and exhaust pressure, input power and suction pressure relation curves;

the performance parameter of the evaporator fan is the relationship between the rotating speed of the fan and the mass flow.

5. An active dynamic cooling control method for an active dynamic cooling control device according to any one of claims 1 to 4, comprising the following steps:

a heat transfer step: the refrigerant in the evaporator evaporates and absorbs heat to reduce the temperature of the wall surface of the evaporator, and the cold energy obtained by temperature reduction is transferred to the air in the cooling space through convection heat exchange and then further transferred to the cooled object;

and (3) adjusting: during the heat transfer step, the controller combines the real-time collected operation parameters according to the stored performance parameters of the compressor and the evaporator, and adjusts the opening of the control valve to realize the dynamic balance of the output cold quantity of the compressor and the heat exchange quantity of the cooled object in the refrigeration process until the temperature of the cooled object reaches the set level.

6. The active dynamic cooling control method according to claim 5, wherein when the heat transfer amount between the refrigerant and the cooled object is limited by the output cooling capacity of the compressor, the control valve maintains the maximum opening degree, so that the compressor outputs the maximum cooling capacity, and the cooling speed of the cooled object is fastest.

7. The active dynamic cooling control method according to claim 5, wherein in the active dynamic cooling control method, when the heat transfer amount between the refrigerant and the object to be cooled is limited by the convective heat transfer coefficient, the control valve maintains a minimum opening degree, so that the evaporation temperature and the object to be cooled maintain a maximum heat transfer temperature difference, and the cooling speed of the object to be cooled is fastest.

Images