TWI897716B - Operating temperature of heat component with variable calorific value control system - Google Patents

Abstract

An operating temperature of heat component with variable calorific value control system is provided. A liquid-gas phase change is a major heat dissipation path of the system to achieve thermal management. Target pressure in vapor chamber is calculated according to operating temperature and pressure in vapor chamber when operating temperature is controlled to junction temperature. Valve opening range of external circulation control valve, internal circulation control valve and/or pressure control valve is/are controlled by controller to achieve target pressure value in vapor chamber. Therefore, the control of operating temperature of heat component which has variable heat flux can be achieved.

Description

Heating element operating temperature control system with variable heating capacity

A temperature control system, particularly a heat sink based on liquid-gas phase transition, calculates a target pressure value within the heat sink, and/or a coolant flow rate and/or a coolant temperature based on operating temperature changes and the pressure within the heat sink to control the operating temperature of a heating element with a variable heat output.

In the past, heat dissipation from heating elements was achieved through air cooling. When the heat output of the heating element was high, the air flow rate could be increased to increase the heat dissipation capacity. However, with the development and evolution of technology, liquid cooling has become the mainstream cooling method for high-heat-generating elements. For example, in servers, liquid cooling can easily meet the heat dissipation and energy consumption requirements of heating elements with a heat output greater than 400W.

However, liquid cooling still suffers from the problem of insufficient precision in controlling the operating temperature of the heating elements. Specifically, there is only one pump providing coolant flow within the server cabinet, while the cabinet contains numerous servers. Each server has a varying number of heating elements (including CPUs and GPUs). Each heating element generates varying amounts of heat, making it difficult to distribute a varying flow of coolant to each element.

Therefore, the current server cooling strategy is to provide maximum water flow without control. However, this design can cause significant fluctuations in the temperature of the heating element as the heat output fluctuates. Even if the operating temperature of the heating element is controlled within specifications, the element will still be affected by thermal stress changes due to the operating temperature fluctuations, causing material fatigue and shortening the life of the heating element.

In summary, it can be seen that the prior art has long suffered from insufficient precision in controlling the operating temperature of heating elements with variable heat output. Therefore, it is necessary to propose improved technical means to solve this problem.

In view of the problem that the prior art has insufficient accuracy in controlling the operating temperature of a heating element with variable heating capacity, the present invention discloses a system for controlling the operating temperature of a heating element with variable heating capacity, wherein:

The present invention discloses a variable heating element operating temperature control system, which includes a heating element, a temperature sensor, a heat sink, a heat exchanger, an external circulation control valve, a pump, an internal circulation control valve, a pressure sensor, a pressure control valve, and a controller.

The temperature sensor is connected to the heating element to sense the working temperature of the heating element; the bottom surface of the heat sink is attached to the heating element to transfer the heat energy of the heating element. The heat sink has a cooling liquid inlet, a liquid vapor outlet and a pressure control port. The cooling liquid enters the heat sink from the cooling liquid inlet, and the cooling liquid absorbs the heat energy of the heating element to form a liquid high-temperature liquid and a gaseous high-temperature vapor, which are discharged from the liquid vapor outlet; the heat exchanger is connected to the heating element to sense the working temperature of the heating element; the bottom surface of the heat sink is attached to the heating element to transfer the heat energy of the heating element; the cooling liquid enters the heat sink from the cooling liquid inlet, and the cooling liquid absorbs the heat energy of the heating element to form a liquid high-temperature liquid and a gaseous high-temperature vapor, which are discharged from the liquid vapor outlet; the heat exchanger is connected to the heating element to sense the working temperature of the heating element ... The heat exchanger has an internal circulation inlet, an internal circulation outlet, an external circulation inlet, and an external circulation outlet. The internal circulation inlet is connected to the accumulated liquid vapor outlet. The high-temperature accumulated liquid and high-temperature vapor enter through the internal circulation inlet and perform heat exchange with the external circulation. The cooling liquid is discharged from the internal circulation outlet. The external cooling liquid enters through the external circulation inlet and performs heat exchange with the internal circulation. The heating liquid is discharged from the external circulation outlet to achieve heat exchange between the internal and external circulations. The external circulation control valve is connected to the external circulation inlet to control the flow of external coolant according to the valve opening range, so as to control the temperature of the cooling liquid discharged from the internal circulation outlet; the pump is connected to the internal circulation outlet to provide the flow momentum of the cooling liquid; the internal circulation control valve is connected to the pump and the coolant inlet to control the flow of coolant entering the heat sink according to the valve opening range; the pressure sensor is connected to the pressure control port to sense the heat sink The pressure value within the device; the pressure control valve is connected to the pressure sensor to control the pressure value within the heat sink based on the valve opening range; the controller is connected to the temperature sensor, the external circulation control valve, the internal circulation control valve, the pressure sensor, and the pressure control valve respectively, obtains the operating temperature from the temperature sensor and the pressure value within the heat sink from the pressure sensor. When the operating temperature is controlled to be the junction temperature, the target pressure value within the heat sink is calculated based on the operating temperature and the pressure value within the heat sink, and the valve opening range of the external circulation control valve, the internal circulation control valve, and/or the pressure control valve is controlled to achieve the target pressure value within the heat sink.

The system disclosed herein, as described above, calculates a target pressure within the heat sink based on the operating temperature and the pressure within the heat sink when the operating temperature is controlled to be the junction temperature. The controller then controls the valve opening of the external circulation control valve, the internal circulation control valve, and/or the pressure control valve to achieve the target pressure within the heat sink.

Through the above-mentioned technical means, the present invention can achieve the technical effect of accurately controlling the operating temperature of the heating element with variable heating amount.

The following will be used in conjunction with drawings and embodiments to explain in detail the implementation of the present invention, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

The following first explains the variable heating capacity heating element working temperature control system disclosed in the present invention, and please refer to "Figure 1", which is a schematic diagram of the structure of the variable heating capacity heating element working temperature control system of the present invention.

The present invention discloses a variable heat generating element operating temperature control system comprising a heat generating element 10, a temperature sensor 11, a heat sink 12, a heat exchanger 13, an external circulation control valve 14, a pump 15, an internal circulation control valve 16, a pressure sensor 17, a pressure control valve 18, and a controller 19.

The heating element 10 may be, for example, a central processing unit (CPU), a graphics processing unit (GPU), etc., for example, as examples, and not intended to limit the scope of application of the present invention. The temperature sensor 11 is connected to the heating element 10 to sense the operating temperature of the heating element 10. Furthermore, the heating element 10 may further include a built-in temperature sensor 11. For example, the temperature sensor 11 may be a thermocouple, a thermistor, or a non-contact infrared temperature sensor, etc., for example, as examples, and not intended to limit the scope of application of the present invention.

The bottom surface of the heat sink 12 is attached to the heating element 10 to transfer the heat energy of the heating element 10. The heat sink 12 has a coolant inlet 121, an accumulated liquid vapor outlet 122, and a pressure control port 123. Coolant enters the heat sink 12 through the coolant inlet 121. After absorbing the heat energy of the heating element 10, the coolant forms a liquid high-temperature accumulated liquid and a gaseous high-temperature vapor, which is discharged through the accumulated liquid vapor outlet 122. The heat sink 12 proposed by the present invention dissipates heat from the heating element 10 through a phase change of the liquid.

Please refer to "Figure 2", which is a cross-sectional view of a heat dissipation device for controlling the working temperature of a heating element with variable heat output according to the present invention.

The heat sink 12 is divided into a high-pressure chamber 125 and a low-pressure chamber 126 by a partition 124. The cooling liquid inlet 121 is connected to the high-pressure chamber 125, and the pressure control port 123 is connected to the low-pressure chamber 126. The partition 124 is provided with a plurality of micro-holes 127. The low-pressure chamber 126 is connected to the liquid vapor outlet 122. The cooling liquid enters the high-pressure chamber 125 in the heat sink 12 through the cooling liquid inlet 121. The cooling liquid is discharged from the high-pressure chamber 125 through the partition 124. When the cooling liquid enters the low-pressure chamber 126 through the multiple micropores 127, the cooling liquid passes through the multiple micropores 127 in the form of droplets, jets, or sprays, etc. This is only an example and does not limit the scope of application of the present invention. The cooling liquid entering the low-pressure chamber 126 contacts the heat sink 128 to absorb the heat energy of the heating element 10 to form liquid high-temperature accumulated liquid and gaseous high-temperature vapor, which is discharged from the accumulated liquid vapor outlet 122.

The heat exchanger 13 has an internal circulation inlet 131, an internal circulation outlet 132, an external circulation inlet 133, and an external circulation outlet 134. The internal circulation inlet 131 is connected to the accumulated liquid vapor outlet 122. High-temperature accumulated liquid and high-temperature vapor enter through the internal circulation inlet 131 and exchange heat with the cooling liquid of the external circulation and are discharged through the internal circulation outlet 132. External coolant enters through the external circulation inlet 133 and exchanges heat with the heated liquid of the internal circulation and is discharged through the external circulation outlet 134, thereby achieving heat exchange between the internal and external circulations.

The external circulation control valve 14 is connected to the external circulation inlet 133 to control the flow of the external cooling liquid according to the valve opening range, so as to control the temperature of the cooling liquid discharged from the internal circulation outlet 132. The pump 15 is connected to the internal circulation outlet 132 to provide the flow momentum of the cooling liquid. The internal circulation control valve 16 is connected to the pump 15 and the cooling liquid inlet 121 to control the flow of the cooling liquid into the heat sink 12 according to the valve opening range. The pressure sensor 17 is connected to the pressure control port 123 to sense the pressure within the heat sink 12. The pressure sensor 17 may be, for example, a piezoresistive pressure sensor, a capacitive pressure sensor, a piezoelectric pressure sensor, a resonant pressure sensor, etc. These examples are provided for illustration only and do not limit the scope of application of the present invention. The pressure control valve 18 is connected to the pressure sensor 17 to control the pressure within the heat sink 12 based on the valve opening range.

The controller 19 is connected to the temperature sensor 11, the external circulation control valve 14, the internal circulation control valve 16, the pressure sensor 17, and the pressure control valve 18, respectively. The controller 19 obtains the operating temperature from the temperature sensor 11 and the pressure value within the heat sink 12 from the pressure sensor 17. When the operating temperature is controlled to be the junction temperature, the controller 19 calculates the target pressure value within the heat sink 12 based on the operating temperature and the pressure value within the heat sink 12. The controller 19 controls the valve opening range of the external circulation control valve 14, the internal circulation control valve 16, and/or the pressure control valve 18 to achieve the target pressure value within the heat sink 12.

Specifically, the junction temperature of the heating element 10 when the heat output changes is as follows:

Among them, is the time, is the temperature, is the junction temperature of the heating element 10 when it reaches a stable state after changing the heat generation, is the initial working temperature, and is the material property parameter of the heating element 10.

The junction temperature of the heating element 10 when it reaches a stable state after changing the heat output is calculated based on the operating temperature of the heating element 10 measured by the temperature sensor 11 at different time points:

Since the time points and are known, and are constants that can be known in advance, the junction temperature of the heating element 10 when it reaches a stable state after changing the heat output can be deduced as:

A curve 31 showing the relationship between heat flux density and junction temperature at different saturation pressures (i.e., and is for illustrative purposes only and does not limit the scope of application of the present invention) is shown in FIG3 . FIG3 shows a data diagram of junction temperature and heat flux density at different saturation pressures for controlling the working temperature of the heating element with variable heat output of the present invention. That is, the junction temperature of the heating element 10 can be controlled by controlling the pressure value within the heat sink 12.

When the pressure value in the heat sink 12 is , the temperature sensor 11 obtains the operating temperature of the heating element 10. When the power of the heating element 10 changes, the junction temperature when the power of the current heating element 10 reaches a stable state is calculated to be . The corresponding curve can be used to obtain the current heat flux density as . Then, the pressure that satisfies and is obtained by interpolation. The controller 19 controls the pressure control valve 18 so that the target pressure value in the heat sink 12 is adjusted to , and the junction temperature of the controllable heating element 10 is .

In addition, the controller 19 further calculates the flow rate and/or temperature of the coolant in the heat sink 12 based on the operating temperature and the pressure value in the heat sink 12, and controls the valve opening range of the external circulation control valve 14, the internal circulation control valve 16, and/or the pressure control valve 18 to achieve the flow rate and/or temperature of the coolant in the heat sink 12.

Referring again to Figure 1, the pressure control valve 18, pump 15, and internal circulation outlet 132 are further connected to the storage tank 21. The pressure source 22 is also connected to the storage tank 21. The coolant stored in the storage tank 21 is condensed by the steam in the pipeline. When the pressure in the heat sink 12 needs to be lowered, the pressure control valve 18 is adjusted, allowing the steam to flow out of the high-pressure heat sink 12. After passing through the heat exchanger 13, it condenses into liquid and flows into the low-pressure storage tank 21. Simultaneously, the pressure inside the heat sink 12 decreases. When the pressure inside the heat sink 12 needs to increase, the pressure control valve 18 is adjusted to allow the steam to continue to heat the heat sink 12, causing the internal pressure to rise. If the coolant in the storage tank 21 becomes excessive, the liquid needs to be recirculated. The storage tank 21 is used to adjust the pressure inside the heat sink 12.

In summary, when the operating temperature is controlled as the junction temperature, the target pressure within the heat sink is calculated based on the operating temperature and the pressure within the heat sink. The controller then controls the valve opening of the external circulation control valve, the internal circulation control valve, and/or the pressure control valve to achieve the target pressure within the heat sink.

This technical approach can solve the problem of insufficient precision in controlling the operating temperature of heating elements with variable heating output in the prior art, thereby achieving the technical effect of accurately controlling the operating temperature of heating elements with variable heating output.

While the embodiments disclosed above are intended to limit the scope of patent protection for this invention, these are not intended to directly limit the scope of patent protection for this invention. Anyone skilled in the art may make minor changes in the form and details of the implementation without departing from the spirit and scope of this invention. The scope of patent protection for this invention shall remain subject to the scope of the attached patent application.

10: Heating element 11: Temperature sensor 12: Heat sink 121: Coolant inlet 122: Accumulated liquid vapor outlet 123: Pressure control port 124: Baffle 125: High-pressure chamber 126: Low-pressure chamber 127: Micropore 13: Heat exchanger 131: Internal circulation inlet 132: Internal circulation outlet 133: External circulation inlet 134: External circulation outlet 14: External circulation control valve 15: Pump 16: Internal circulation control valve 17: Pressure sensor 18: Pressure control valve 19: Controller 21: Storage tank 22: Stress Source 31: Relationship Curve

Figure 1 is a schematic diagram of the architecture of the variable heating capacity heating element operating temperature control system of the present invention. Figure 2 is a cross-sectional view of the heat dissipation device used for the variable heating capacity heating element operating temperature control of the present invention. Figure 3 is a graph showing the junction temperature and heat flux density data for different saturation pressures of the variable heating capacity heating element operating temperature control of the present invention.

10: Heating element

11: Temperature sensor

12: Heat dissipation device

121: Coolant inlet

122: Effluent steam outlet

123: Pressure control port

13: Heat exchanger

131: Internal circulation entrance

132: Internal circulation outlet

133: External circulation entrance

134: External circulation outlet

14: External circulation control valve

15: Pumping

16: Internal circulation control valve

17: Pressure sensor

18: Pressure control valve

19: Controller

21: Storage Slot

22: Source of Pressure

Claims (8)

A heating element operating temperature control system with variable heat output comprises: A heating element; A temperature sensor connected to the heating element to sense an operating temperature of the heating element; A heat sink, the bottom surface of which is in contact with the heating element to transfer heat energy from the heating element. The heat sink has a coolant inlet, an accumulated liquid vapor outlet, and a pressure control port. Coolant enters the heat sink through the coolant inlet, absorbs heat energy from the heating element, forms a liquid high-temperature accumulated liquid, and forms a gaseous high-temperature vapor, which is discharged through the accumulated liquid vapor outlet. A heat exchanger having an internal circulation inlet, an internal circulation outlet, an external circulation inlet, and an external circulation outlet. The internal circulation inlet is connected to the accumulated liquid vapor outlet. High-temperature accumulated liquid and high-temperature vapor enter through the internal circulation inlet and exchange heat with the external circulation as cooling liquid, which is discharged through the internal circulation outlet. External coolant enters through the external circulation inlet and exchanges heat with the internal circulation as warming liquid, which is discharged through the external circulation outlet, thereby achieving heat exchange between the internal and external circulations. An external circulation control valve is connected to the external circulation inlet to control the flow rate of the external coolant based on the valve opening range, thereby controlling the temperature of the cooling liquid discharged from the internal circulation outlet. A pump connected to the internal circulation outlet to provide flow momentum for the cooling liquid; An internal circulation control valve connected to the pump and the coolant inlet to control the flow of coolant into the heat sink based on the valve opening range; A pressure sensor connected to the pressure control port to sense the pressure within the heat sink; A pressure control valve connected to the pressure sensor to control the pressure within the heat sink based on the valve opening range; and A controller is connected to the temperature sensor, the external circulation control valve, the internal circulation control valve, the pressure sensor, and the pressure control valve, respectively. The controller obtains the operating temperature from the temperature sensor and the pressure value within the heat sink from the pressure sensor. When the operating temperature is controlled to a junction temperature, the controller calculates a target pressure value within the heat sink based on the operating temperature and the pressure value within the heat sink. The controller then controls the valve opening range of the external circulation control valve, the internal circulation control valve, and/or the pressure control valve to achieve the target pressure value within the heat sink. As described in claim 1, the working temperature control system of the heating element with variable heating value, wherein the heat dissipation device is divided into a high-pressure chamber and a low-pressure chamber by a partition, the cooling liquid inlet is connected to the high-pressure chamber, and the low-pressure chamber is connected to the accumulated liquid vapor outlet, and the partition is provided with multiple micropores. A working temperature control system for a heating element with variable heating capacity as described in claim 2, wherein the pressure control port is connected to the low-pressure chamber. As described in claim 2, the operating temperature control system of a heating element with variable heating value, wherein when the cooling liquid enters the low-pressure chamber from the high-pressure chamber through the multiple micropores provided on the partition, the cooling liquid is in the form of droplets, jets or sprays. The working temperature control system of the heating element with variable heating value as described in claim 1, wherein the pressure control valve, the pump and the internal circulation outlet are further connected to a storage tank, a pressure source is connected to the storage tank, the storage tank stores liquid coolant and gaseous gas, the storage tank provides flow replenishment and storage of the internal circulation coolant, and the storage tank provides adjustment of the pressure value in the heat dissipation device. The operating temperature control system for a heating element with variable heating value as described in claim 1, wherein the temperature sensor is a thermocouple, a thermistor, or non-contact infrared temperature sensing. The operating temperature control system of a heating element with variable heating value as described in claim 1, wherein the pressure sensor is a piezoresistive pressure sensor, a capacitive pressure sensor, a piezoelectric pressure sensor or a resonant pressure sensor. A working temperature control system for a heating element with variable heating value as described in claim 1, wherein the controller further calculates the flow rate of the coolant and/or the temperature of the coolant based on the working temperature and the pressure value in the heat sink, and controls the valve opening range of the external circulation control valve, the internal circulation control valve and/or the pressure control valve to achieve the flow rate of the coolant and/or the temperature of the coolant in the heat sink.