Temperature control system and method of two-way liquid cooling machine for energy storage

Abstract

The invention relates to the technical field of liquid cooling machine temperature control, in particular to a temperature control system and method of a two-way liquid cooling machine for energy storage, and the system comprises a refrigeration module, the refrigeration module comprises a compressor, a condenser and a PACK plate heat exchanger, the PACK plate heat exchanger is used for carrying out heat exchange with a water way on the PACK side, and forced refrigeration of the water way on the PACK side is achieved; according to the scheme, when the environment temperature is low, the temperature control requirement can be met only through natural air cooling heat dissipation, energy consumption is low, and meanwhile the problem of frequent starting and stopping of the refrigeration module is avoided; due to the fact that high and low temperature control requirements are distinguished and effectively associated, under the condition that energy is saved, the temperature control precision is higher, the requirement for control difficulty is further lowered, and batch production and quality control are facilitated; through forced association and control of high temperature and low temperature, the temperature difference between a high-temperature area and a low-temperature area is fully utilized, only one three-way water valve is utilized to control the flow, heat exchange is conducted through a PCS plate heat exchanger, and the method is stable and reliable.

Description

Technical Field

[0001] This invention relates to the field of liquid chiller temperature control technology, and in particular to a temperature control system and method for a dual-channel liquid chiller for energy storage. Background Technology

[0002] In the field of electrochemical energy storage temperature control, electrochemical energy storage temperature control systems play a crucial role due to the stringent operating temperature requirements of lithium batteries. Meanwhile, PCS (Precipitated Cell Storage System) also has temperature control requirements. However, the temperature control requirements of PCS differ from those of batteries. PCS typically operates between 35 and 45°C, while batteries generally operate between 15 and 35°C, with an optimal range of 25°C. This results in different temperature control needs. If a low supply water temperature is used, condensation is likely to occur on the PCS; if a high outlet water temperature is used, battery temperature control cannot be guaranteed.

[0003] Traditional liquid chiller units employ forced cooling and are controlled separately through dual water circuits. While this meets basic temperature control requirements, it lacks advantages in energy saving and condensation prevention. The main temperature control aspect of existing technologies involves a plate heat exchanger in the cooling module providing cooling to the PACK-side water circuit, and adding a water-to-water plate heat exchanger in the return water test to provide cooling to the PCS's water circuit. The main drawback of this temperature control scheme is that even when the ambient temperature is not high, the cooling module still needs to be activated for cooling, resulting in high energy consumption. Furthermore, when the PACK is not generating heat but the PCS side requires cooling, the cooling module also needs to be activated, potentially leading to excessively low temperatures on the PACK side, making temperature control difficult. Therefore, a temperature control system and method for a dual-circuit liquid chiller for energy storage is proposed. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a temperature control system and method for a dual-channel liquid chiller for energy storage.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A temperature control system and method for a dual-channel liquid chiller for energy storage includes a refrigeration module, which includes a compressor, a condenser, and a PACK heat exchanger. The PACK heat exchanger is used to exchange heat with the water circuit on the PACK side to achieve forced cooling of the water circuit on the PACK side. The natural cooling module includes a water pump, a natural cooling heat exchanger, and a PCS plate heat exchanger. The water pump is used to pump coolant to the natural cooling heat exchanger, which is used to dissipate heat to the outside. The PCS plate heat exchanger is used to exchange heat with the water circuit on the PCS side. A three-way water valve is connected between the PACK heat exchanger and the PCS heat exchanger to control the cooling flow through the PCS heat exchanger, thereby enabling heat exchange of the coolant between the forced cooling module and the natural cooling module. The PTC heater is installed in the water circuit on the PACK side and is used to heat the water circuit on the PACK side or the water circuits on both sides of the PACK and PCS. The fan is shared by the condenser and the natural cooling heat exchanger of the refrigeration module and is used to provide heat dissipation power for the condenser or the natural cooling heat exchanger. The control module is electrically connected to the compressor, water pump, three-way water valve, PTC heater, fan and temperature sensor respectively. The temperature sensor is used to collect the water temperature on the PACK side and the water temperature on the PCS side.

[0006] Preferably, the temperature sensor includes a first sensor group disposed on the PACK side and a second sensor group disposed on the PCS side, and the control module controls the working status of each component based on the data collected by the first sensor group and the second sensor group.

[0007] A temperature control method for a temperature control system of a dual-channel liquid chiller for energy storage includes the following modes: Natural cooling mode: When the temperature on the PCS side is higher than the preset PCS cooling threshold and the temperature on the PACK side is lower than the preset PACK cooling threshold; If the heat dissipation capacity of the natural cooling module meets the cooling requirements of the PCS side, the control module controls the three-way water valve to close, the fan is started by the temperature control of the PCS side, the cooling module does not work, and the PCS side is cooled by the natural cooling module. If the heat dissipation capacity of the natural cooling module cannot meet the cooling requirements of the PCS side, the control module controls the three-way water valve to open, and the coolant on the PACK side participates in the cooling of the PCS side. When the temperature on the PACK side rises to the preset PACK cooling threshold, the control module starts the compressor of the refrigeration module, and the fan is switched to be controlled by the refrigeration module. The temperature on the PCS side is controlled by adjusting the opening degree of the three-way water valve. Forced cooling mode: The temperature on the PACK side is higher than the preset PACK cooling threshold, and the temperature on the PCS side is lower than the preset PCS cooling threshold. The control module controls the three-way water valve to be fully open. The cold water from the natural cooling module flows through the PACK board to cool the PACK side, and then through the PCS board to cool the PCS side. The fan is controlled by the temperature of the PCS side. When the PACK side temperature continues to rise to the threshold requiring forced cooling, the control module starts the compressor of the cooling module, and the fan is switched to be controlled by the cooling module. The temperature of the PCS side is controlled by adjusting the opening of the three-way water valve. Heating mode: Heating control; When heating is required only on the PACK side, the control module starts the PTC heater, controls the three-way water valve to be fully closed, and the fan does not work; When both the PACK side and the PCS side require heating, the control module starts the PTC heater, controls the three-way water valve to be fully open, and the fan does not work.

[0008] Preferably, the temperature control method monitors the inlet and outlet water temperatures of the battery pack, the inlet and outlet water temperatures of the PCS, and the ambient temperature, and the control module automatically determines and switches the operating mode.

[0009] Preferably, the temperature rises on the PCS side before that on the PACK side. When the temperature on the PCS side reaches the preset start-up threshold, the control module first starts the fan to dissipate heat from the natural cooling heat exchanger, and the compressor of the refrigeration module does not work temporarily. At this time, the PCS side adopts natural cooling to reduce the temperature.

[0010] The beneficial effects of this invention are: This solution meets temperature control requirements through natural air cooling alone when the ambient temperature is low, resulting in low energy consumption and avoiding frequent start-stop issues of the refrigeration module. By differentiating and effectively correlating high and low temperature control needs, it achieves higher temperature control accuracy while maintaining energy efficiency, further reducing control complexity and facilitating mass production and quality control. Through forced correlation and control of high and low temperatures, it fully utilizes the temperature difference between the high and low temperature zones, using only a single three-way water valve to control flow and exchange heat via the PCS heat exchanger, ensuring a stable and reliable method. By sharing a single fan between the condenser of the refrigeration module and the natural cooling radiator, and by switching modes between different scenarios, it achieves effective dual-system control and reduces costs. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the temperature control system for a dual-channel liquid chiller for energy storage proposed in this invention. Figure 2 This is a schematic diagram illustrating the principle of the prior art of this invention. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0013] Example: Refer to Figure 1 A temperature control system and method for a dual-channel liquid chiller for energy storage, including a refrigeration module, the refrigeration module including a compressor, a condenser and a PACK heat exchanger, the PACK heat exchanger being used to exchange heat with the water circuit on the PACK side to achieve forced cooling of the water circuit on the PACK side; The natural cooling module includes a water pump, a natural cooling heat exchanger, and a PCS plate heat exchanger. The water pump is used to pump coolant to the natural cooling heat exchanger, which is used to dissipate heat to the outside. The PCS plate heat exchanger is used to exchange heat with the water circuit on the PCS side. The three-way water valve is connected between the PACK heat exchanger and the PCS heat exchanger. It is used to control the cooling flow through the PCS heat exchanger and realize the heat exchange of coolant between the forced cooling module and the natural cooling module. PTC heater, the PTC heater is installed in the water circuit on the PACK side, and is used to heat the water circuit on the PACK side or the water circuit on both sides of the PACK and PCS. The fan is shared by the condenser and the natural cooling heat exchanger of the refrigeration module, and is used to provide heat dissipation power for the condenser or the natural cooling heat exchanger. The control module is electrically connected to the compressor, water pump, three-way water valve, PTC heater, fan and temperature sensor respectively. The temperature sensor is used to collect the water temperature on the PACK side and the water temperature on the PCS side.

[0014] Specifically, the temperature sensor includes a first sensor group located on the PACK side and a second sensor group located on the PCS side. The control module controls the working status of each component based on the data collected by the first and second sensor groups. The sensor group includes: an outlet water pressure sensor, an outlet water temperature sensor, a return water pressure sensor, and a return water temperature sensor. The temperature control system also includes an injection valve, a filter, a circulation pump, an expansion valve, an automatic venting valve, an expansion tank, a gas pipe temperature sensor, a liquid pipe temperature sensor, an exhaust temperature sensor, a high-pressure sensor, and the first sensor.

[0015] A temperature control method for a temperature control system of a dual-channel liquid chiller for energy storage includes the following modes: Natural cooling mode: When the temperature on the PCS side is higher than the preset PCS cooling threshold and the temperature on the PACK side is lower than the preset PACK cooling threshold; If the heat dissipation capacity of the natural cooling module meets the cooling requirements of the PCS side, the control module controls the three-way water valve to close, the fan is started by the temperature control of the PCS side, the cooling module does not work, and the PCS side is cooled by the natural cooling module. If the heat dissipation capacity of the natural cooling module cannot meet the cooling requirements of the PCS side, the control module controls the three-way water valve to open, and the coolant on the PACK side participates in the cooling of the PCS side. When the temperature on the PACK side rises to the preset PACK cooling threshold, the control module starts the compressor of the refrigeration module, and the fan is switched to be controlled by the refrigeration module. The temperature on the PCS side is controlled by adjusting the opening degree of the three-way water valve. Forced cooling mode: The temperature on the PACK side is higher than the preset PACK cooling threshold, and the temperature on the PCS side is lower than the preset PCS cooling threshold. The control module controls the three-way water valve to be fully open. The cold water from the natural cooling module flows through the PACK board to cool the PACK side, and then through the PCS board to cool the PCS side. The fan is controlled by the temperature of the PCS side. When the PACK side temperature continues to rise to the threshold requiring forced cooling, the control module starts the compressor of the cooling module, and the fan is switched to be controlled by the cooling module. The temperature of the PCS side is controlled by adjusting the opening of the three-way water valve. Heating mode: Heating control; When heating is required only on the PACK side, the control module starts the PTC heater, controls the three-way water valve to be fully closed, and the fan does not work; When both the PACK side and the PCS side require heating, the control module starts the PTC heater, controls the three-way water valve to be fully open, and the fan does not work.

[0016] Furthermore, the temperature control method monitors the inlet and outlet water temperatures of the battery pack, the inlet and outlet water temperatures of the PCS, and the ambient temperature, and the control module automatically determines and switches the operating mode accordingly.

[0017] Furthermore, the temperature rises on the PCS side before that on the PACK side. When the temperature on the PCS side reaches the preset start-up threshold, the control module first starts the fan to dissipate heat from the natural cooling heat exchanger, and the compressor of the refrigeration module does not work temporarily. At this time, the PCS side uses natural cooling to cool down.

[0018] Control methods for different scenarios: When the water temperature on the PCS side is too high while the water temperature on the PACK side is not high, the three-way water valve will not work if natural cooling is sufficient. When it is insufficient, the three-way water valve will open, and the water on the PACK side will participate in cooling the PCS side. The water on the PACK side will heat up on its own. When it heats up to the point where forced cooling is required, the compressor of the cooling module will start to perform forced cooling. The control of the cooling fan will be changed to the control of the cooling module, and the temperature control of the PCS will be controlled by the opening degree of the three-way water valve. When the temperature on the PCS side is not high while the temperature on the PACK side reaches the cooling point, the three-way valve is fully open. Naturally cooled water cools the PACK side and then the PCS side. At this time, the heat is concentrated on the PCS side, so the fan control is still determined by the PCS temperature. When the temperature on the PACK side rises and forced cooling is required, the compressor of the cooling module starts to perform forced cooling. The control of the cooling fan is switched to the control of the cooling module, and the temperature control of the PCS is controlled by the opening degree of the three-way water valve. Under normal circumstances, only the PACK side needs heating. At this time, the PTC heater is started and the three-way water valve is fully closed. When both the PACK side and the PCS side need heating, the PTC heater is started, the three-way water valve is fully opened, and the cooling fan does not work, which can meet the heating needs of both sides.

[0019] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0020] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0021] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A temperature control system for a dual-channel liquid chiller for energy storage, characterized in that, include: A refrigeration module, comprising a compressor, a condenser, and a PACK heat exchanger, wherein the PACK heat exchanger is used to exchange heat with the water circuit on the PACK side to achieve forced cooling of the water circuit on the PACK side; The natural cooling module includes a water pump, a natural cooling heat exchanger, and a PCS plate heat exchanger. The water pump is used to pump coolant to the natural cooling heat exchanger, which is used to dissipate heat to the outside. The PCS plate heat exchanger is used to exchange heat with the water circuit on the PCS side. A three-way water valve is connected between the PACK heat exchanger and the PCS heat exchanger to control the cooling flow through the PCS heat exchanger, thereby enabling heat exchange of the coolant between the forced cooling module and the natural cooling module. The PTC heater is installed in the water circuit on the PACK side and is used to heat the water circuit on the PACK side or the water circuits on both sides of the PACK and PCS. The fan is shared by the condenser and the natural cooling heat exchanger of the refrigeration module and is used to provide heat dissipation power for the condenser or the natural cooling heat exchanger. The control module is electrically connected to the compressor, water pump, three-way water valve, PTC heater, fan and temperature sensor respectively. The temperature sensor is used to collect the water temperature on the PACK side and the water temperature on the PCS side.

2. The temperature control system for a dual-channel liquid chiller for energy storage according to claim 1, characterized in that, The temperature sensor includes a first sensor group disposed on the PACK side and a second sensor group disposed on the PCS side. The control module controls the working status of each component based on the data collected by the first sensor group and the second sensor group.

3. A temperature control method for a temperature control system applied to a dual-channel liquid chiller for energy storage as described in any one of claims 1-2, characterized in that, Includes the following modes: Natural cooling mode: When the temperature on the PCS side is higher than the preset PCS cooling threshold and the temperature on the PACK side is lower than the preset PACK cooling threshold; If the heat dissipation capacity of the natural cooling module meets the cooling requirements of the PCS side, the control module controls the three-way water valve to close, the fan is started by the temperature control of the PCS side, the cooling module does not work, and the PCS side is cooled by the natural cooling module. If the heat dissipation capacity of the natural cooling module cannot meet the cooling requirements of the PCS side, the control module controls the three-way water valve to open, and the coolant on the PACK side participates in the cooling of the PCS side. When the temperature on the PACK side rises to the preset PACK cooling threshold, the control module starts the compressor of the refrigeration module, and the fan is switched to be controlled by the refrigeration module. The temperature on the PCS side is controlled by adjusting the opening degree of the three-way water valve. Forced cooling mode: The temperature on the PACK side is higher than the preset PACK cooling threshold, and the temperature on the PCS side is lower than the preset PCS cooling threshold. The control module controls the three-way water valve to be fully open. The cold water from the natural cooling module flows through the PACK board to cool the PACK side, and then through the PCS board to cool the PCS side. The fan is controlled by the temperature of the PCS side. When the PACK side temperature continues to rise to the threshold requiring forced cooling, the control module starts the compressor of the cooling module, and the fan is switched to be controlled by the cooling module. The temperature of the PCS side is controlled by adjusting the opening of the three-way water valve. Heating mode: Heating control; When heating is required only on the PACK side, the control module starts the PTC heater, controls the three-way water valve to be fully closed, and the fan does not work; When both the PACK side and the PCS side require heating, the control module starts the PTC heater, controls the three-way water valve to be fully open, and the fan does not work.

4. The temperature control method according to claim 3, characterized in that, The temperature control method monitors the inlet and outlet water temperatures of the battery pack, the inlet and outlet water temperatures of the PCS, and the ambient temperature, and the control module automatically determines and switches the operating mode accordingly.

5. The temperature control method according to claim 4, characterized in that, The temperature rises on the PCS side before that on the PACK side. When the temperature on the PCS side reaches the preset start-up threshold, the control module first starts the fan to dissipate heat from the natural cooling heat exchanger. The compressor of the refrigeration module does not work temporarily. At this time, the PCS side uses natural cooling to cool down.

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