Method for operating a gas internal combustion engine driven direct-cooling block ice maker and ice melter unit

Abstract

The application discloses a kind of gas internal combustion engine driving type straight cold block ice making and ice melting unit operation method, including refrigerant circulation, antifreeze circulation and cooling water circulation.Refrigerant circulation is driven by gas internal combustion engine compression mechanism, to realize the compression, condensation, throttling, evaporation and gas-liquid separation of refrigerant;Antifreeze circulation absorbs internal combustion engine waste heat, through temperature control switching path, to maintain temperature and recover waste heat to cooling water system;Cooling water circulation absorbs refrigerant and antifreeze heat through heat recovery process, stored in heat storage water tank, then used for heat dissipation or provides heat source for ice melting through ice melting flow channel.The method replaces electric drive with gas engine, solves power capacity problem, and has low operating cost in gas low price area;Through waste heat recovery for ice melting, avoid refrigerant reverse circulation, improve primary energy utilization rate, reduce cost.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and in particular to an operating method for a gas-fired internal combustion engine-driven direct-cooling block ice-making and de-icing unit. Background Technology

[0002] Large-format, non-edible block ice has a wide range of applications in industrial production, commercial preservation, and many other fields. It provides a stable cold source for low-temperature storage, industrial process cooling, and cooling in special scenarios, and is an important basic consumable for ensuring the normal operation of related industries. As the demand for block ice continues to increase in various fields, the core performance indicators of ice-making technology, such as efficiency, energy consumption, and stability, are gradually becoming key factors restricting the development of the industry.

[0003] Currently, the mainstream block ice preparation technologies on the market are mainly divided into two categories: brine ice making and direct-cooling electric-driven ice makers using hot fluorine de-icing. However, both of these ice-making technologies have significant drawbacks, as follows: The ice-making principle of brine ice makers results in low heat exchange efficiency, leading to long ice-making cycles and low overall ice-making efficiency. Furthermore, this technology involves significant energy losses during energy transfer, resulting in low energy utilization. In addition, the use of large storage devices such as brine tanks in brine ice making equipment requires a large footprint, increasing the company's site investment costs.

[0004] For hot fluorine de-icing direct-cooling electric-driven ice makers, the equipment uses electricity as the sole driving energy source. The high-power operation of core components such as the compressor requires a large investment in power capacity expansion. Furthermore, during the de-icing process, the compressor and other components still need to be continuously driven, resulting in a continuous increase in power consumption. On the other hand, the de-icing process relies on hot fluorine, and the ambient temperature directly affects the heat exchange effect of the evaporator, which in turn leads to a large energy consumption for de-icing.

[0005] Chinese patent application number 201910314784.8 discloses "An operating method for a gas engine-driven vapor compression air source heat pump chiller unit." This method integrates two major systems: a heat pump refrigerant circulation system and an engine coolant circulation system. A gas engine drives the compressor, and a four-way reversing valve switches the refrigerant flow to achieve cooling and heating cycles, while also recovering engine exhaust and cylinder liner waste heat. After absorbing waste heat through a flue gas heat exchanger and engine cylinder liners, the coolant flow is controlled by an electric three-way valve and a solenoid valve, forming four circulation modes: self-circulation, waste heat recovery, heat dissipation, and defrosting. The opening of the solenoid valve can be dynamically adjusted according to cooling and heating demands and actual operating conditions. When the coolant is insufficient, it is automatically replenished by the water tank. The unit has two operating modes each for cooling and heating: during low-temperature heating, waste heat is prioritized for defrosting; during cooling, excess waste heat can be dissipated through a fan. This operating method meets the indoor cooling and heating needs of a gas engine-driven vapor compression air source heat pump chiller unit. However, this unit has a single purpose and can only be used for indoor heating or cooling, and cannot meet other requirements. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an operation method for a gas-fired internal combustion engine-driven direct-cooling block ice-making and de-icing unit. This method not only solves the problem of power capacity expansion but also recovers some of the system's waste heat, reduces energy consumption, and achieves normal de-icing without being affected by ambient temperature.

[0007] The present invention provides an operation method for a gas-fired internal combustion engine driven direct-cooling block ice-making and de-icing unit, comprising a refrigerant circulation process, an antifreeze circulation process, and a cooling water circulation process. The refrigerant cycle specifically includes the following steps: A power unit drives a compression mechanism to provide power for the refrigerant cycle. Low-temperature, low-pressure gaseous refrigerant is drawn in and compressed by the compression mechanism, transforming it into high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant then enters an oil separation mechanism to separate out any entrained lubricating oil before entering a condensation mechanism. There, it exchanges heat with the cooling medium and is condensed into a medium-temperature, high-pressure liquid refrigerant. This medium-temperature, high-pressure liquid refrigerant flows through a fluid processing component located downstream of the condensation mechanism for further processing. It is then throttled by a throttling mechanism, transforming into a low-temperature, low-pressure liquid refrigerant. The throttled, low-temperature, low-pressure liquid refrigerant enters an evaporation mechanism, where it exchanges heat with the cooling water, absorbing heat and evaporating into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant exiting the evaporation mechanism then enters a gas-liquid separation mechanism to separate any entrained liquid refrigerant. The separated gaseous refrigerant returns to the suction port of the compression mechanism, completing one refrigerant cycle. The antifreeze circulation process includes the following steps: Antifreeze flows through the power unit via an antifreeze circulation pipeline system to absorb the waste heat generated during the power unit's operation. A temperature sensor monitors the antifreeze temperature in real time. A control unit controls the opening and closing of valves in the antifreeze circulation pipeline system based on a comparison between the real-time antifreeze temperature and a preset target temperature range, switching the antifreeze's flow path. When the antifreeze temperature is below the preset target temperature range, the antifreeze circulates along a first path, flowing through the power unit to quickly raise its temperature to the target range. When the antifreeze temperature reaches or exceeds the preset target temperature range, the antifreeze switches to a second path, flowing through a waste heat recovery heat exchanger to transfer excess heat to the cooling medium within the heat exchanger, thereby lowering the antifreeze temperature and maintaining it within the target temperature range. The cooling water circulation process specifically includes the following steps: Cooling water is driven by a cooling water pump to flow in a cooling water circulation loop, and the flow path of the cooling water in the cooling water circulation loop is regulated by a flow direction control component. The cooling water circulation process includes a heat recovery process, which involves controlling the cooling water to flow sequentially through a plate heat exchanger and a waste heat recovery heat exchanger, exchanging heat with the system's refrigerant and the engine's antifreeze respectively, absorbing heat from the refrigerant and antifreeze and thus being heated. The heated cooling water is then stored in a hot water storage tank. After the cooling water undergoes the heat recovery process and flows out of the hot water storage tank, it is controlled by the flow direction control component to either execute a heat dissipation mode or a de-icing mode operation. During the heat dissipation mode operation, the cooling water in the hot water storage tank is guided to the cooling tower to release heat to the environment; During the de-icing mode, the cooling water in the hot water storage tank is guided to the de-icing channel in the evaporator, using its heat to provide a heat source for the de-icing process.

[0008] The present invention has the following beneficial effects: To compensate for the diversity of existing units and expand the application range of gas engine-driven systems, a gas-fired internal combustion engine-driven direct-cooling block ice-making and de-icing unit is designed. This system mainly consists of a refrigerant circulation system, an antifreeze circulation system, and a cooling water circulation system. The cooling water circulation system replaces electric drive with a gas engine and incorporates a waste heat recovery system, achieved through a hot water storage tank and an ice film with de-icing channels.

[0009] The rational use of a gas engine to drive a heat pump system for ice making effectively solves the problem of increasing power capacity. In some areas with low gas prices, such as industrial parks and tunnel construction sites, the operating cost of using this system for ice making is lower than that of electric ice makers.

[0010] The system employs an ice film with two distinct flow channels and a cleverly designed hot water storage tank. This tank stores waste heat generated during system operation, including heat from the condenser and the recovered gas engine. The warm water then melts the ice layer on the evaporator wall through the de-icing channels within the ice film, thus achieving the de-icing process. This eliminates the need for a reverse cycle in the refrigerant system for de-icing, reducing costs to some extent, improving primary energy efficiency, and lowering the consumption of high-grade electricity. Attached Figure Description

[0011] Figure 1 This is a flowchart of a gas-fired internal combustion engine-driven direct-cooling block ice-making and de-icing unit.

[0012] Figure 2 This is a flowchart illustrating the implementation process of the ice-making unit.

[0013] Figure 3 This is a flowchart illustrating the implementation method of the unit during de-icing operation.

[0014] In the diagram: 1-Open compressor, 2-Oil separator, 3-Plate heat exchanger, 4-Check valve, 5-Liquid storage tank, 6-Dryer filter, 7-Liquid supply solenoid valve, 8-Sight glass, 9-Expansion valve, 10-Ice film, 11-Gas-liquid separator, 12-Gas engine, 13-Antifreeze pump, 14-First solenoid valve, 15-Second solenoid valve, 16-Expansion tank, 17-Waste heat recovery heat exchanger, 18-Hot water storage tank, 19-Cooling water pump, 20-Third solenoid valve, 21-Cooling tower, 22-Fourth solenoid valve, 23-Drain valve. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0016] Figure 1 A method for operating a gas-fired internal combustion engine-driven direct-cooling block ice-making and de-icing unit is provided, including a refrigerant circulation process, an antifreeze circulation process, and a cooling water circulation process; The refrigerant cycle specifically includes the following steps: A power unit drives a compression mechanism to provide power for the refrigerant cycle. Low-temperature, low-pressure gaseous refrigerant is drawn in and compressed by the compression mechanism, transforming it into high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant then enters an oil separation mechanism to separate out any entrained lubricating oil before entering a condensation mechanism. There, it exchanges heat with the cooling medium and is condensed into a medium-temperature, high-pressure liquid refrigerant. This medium-temperature, high-pressure liquid refrigerant flows through a fluid processing component located downstream of the condensation mechanism for further processing. It is then throttled by a throttling mechanism, transforming into a low-temperature, low-pressure liquid refrigerant. The throttled, low-temperature, low-pressure liquid refrigerant enters an evaporation mechanism, where it exchanges heat with the cooling water, absorbing heat and evaporating into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant exiting the evaporation mechanism then enters a gas-liquid separation mechanism to separate any entrained liquid refrigerant. The separated gaseous refrigerant returns to the suction port of the compression mechanism, completing one refrigerant cycle.

[0017] Preferably, combined with Figure 1 As shown, the power unit is a gas engine 12, the compression mechanism is an open-type compressor 1, and the oil separation mechanism is an oil separator 2. The condensation mechanism is a plate heat exchanger 3. The fluid handling assembly includes a one-way valve 4 for preventing refrigerant backflow, a liquid receiver 5 for storing excess refrigerant and stabilizing system pressure, a dryer filter 6 for absorbing moisture, a liquid supply solenoid valve 7 for controlling the flow of liquid refrigerant, and a sight glass 8 for observing the refrigerant status. The throttling mechanism is an expansion valve 9, which can be a thermostatic expansion valve or an electronic expansion valve. The evaporation mechanism employs an ice film 10. This ice film can adopt the structure of "A Direct Cooling Ice-Making Device" disclosed in Chinese Patent Application No. 202222929552.3, filed on November 3, 2022. This structure uses a refrigerant flow channel for the ice-making process, where it exchanges heat with the cooling water in the ice film, absorbing heat from the water and turning the water phase into ice. Another de-icing flow channel carries hot water for the de-icing process after ice making, exchanging heat with the ice blocks to melt the ice on the ice film wall, causing the ice blocks to separate from the wall. The gas-liquid separation mechanism employs a gas-liquid separator 11.

[0018] The specific process of the refrigerant circulation method is as follows: A gas-fired engine 12 drives an open-type compressor 1. Low-temperature, low-pressure gaseous refrigerant with a temperature of -18℃ to 8℃ and a pressure of 0.1MPa to 0.16MPa is drawn into the suction port of the open-type compressor 1. After compression, it becomes a high-temperature, high-pressure gaseous refrigerant with a temperature of 60℃ to 75℃ and a pressure of 1.0MPa to 1.3MPa, and is discharged from the compressor exhaust port. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor exhaust port enters an oil separator 2 to separate the lubricating oil. The refrigerant from the oil separator 2 enters a plate heat exchanger 3, where it exchanges heat with the cooling water flowing through the plate heat exchanger and is condensed into a medium-temperature, high-pressure liquid refrigerant with a temperature of 35℃ to 45℃ and a pressure of 0.89MPa to 1.2MPa. Medium-temperature, high-pressure liquid refrigerant sequentially passes through one-way valve 4, liquid receiver 5, dryer filter 6, liquid supply solenoid valve 7, and sight glass 8. It then passes through expansion valve 9 for throttling, transforming into a low-temperature, low-pressure gaseous refrigerant with a temperature of -25℃ to -15℃ and a pressure of 0.1MPa to 0.16MPa. The throttled refrigerant enters the refrigerant channel of ice film 10, exchanging heat with the cooling water in the ice-making chamber. It absorbs heat from the water, causing the cooling water to freeze, while the refrigerant itself evaporates into a low-temperature, low-pressure gaseous refrigerant with a temperature of -18℃ to -8℃ and a pressure of 0.1MPa to 0.16MPa. The gaseous refrigerant exiting evaporator 10 enters gas-liquid separator 11, separating any entrained droplets to prevent liquid refrigerant from entering compressor 1 and causing liquid slugging. Finally, the separated gaseous refrigerant is returned to the suction port of compressor 1, completing the entire refrigerant cycle.

[0019] Referring to the attached diagram, the specific structure of the refrigerant circulation system for realizing the refrigerant circulation method can be connected as follows: The discharge port of the open compressor 1 is connected in series via a refrigerant delivery pipe to an oil separator 2, a plate heat exchanger 3, a one-way valve 4, a liquid receiver 5, a dryer filter 6, a liquid supply solenoid valve 7, and a sight glass 8; wherein, each adjacent component is sealed together by a refrigerant pipe of appropriate specifications to ensure no refrigerant leakage during transportation. The inlet of the expansion valve 9 is sealed to the outlet of the sight glass 8 via a pipe, and the outlet of the expansion valve 9 is connected to the inlet of a pre-set refrigerant flow channel inside the ice mold 10 via a pipe, for the refrigerant to flow through the refrigerant flow channel in the ice mold 10 to exchange heat with the cooling water. After heat exchange, the refrigerant passes through the outlet end of the refrigerant flow channel inside the ice mold 10 and is connected to the inlet of the gas-liquid separator 11 via a pipe. The outlet of the gas-liquid separator 11 is then connected to the suction port of the open compressor 1 via a refrigerant return pipe, thus forming a complete refrigerant closed loop.

[0020] The antifreeze circulation process includes the following steps: During the operation of the gas engine, it is necessary to recover the waste heat of the cylinder liner and the waste heat of the flue gas through the cooling medium to ensure the stable operation of the gas engine 12. Antifreeze flows through a circulation pipeline system to the power unit (e.g., a gas engine) to absorb waste heat generated during operation. A temperature sensor monitors the antifreeze temperature in real time. A control unit, which can be a PLC or a microcontroller, controls the opening and closing of valves in the antifreeze circulation pipeline system based on a comparison between the real-time antifreeze temperature and a preset target temperature range, switching the antifreeze flow path. When the antifreeze temperature is below the preset target temperature range, the antifreeze circulates along a first path, flowing through the power unit to quickly raise its temperature to the target range. When the antifreeze temperature reaches or exceeds the preset target temperature range, the antifreeze switches to a second path, flowing through a waste heat recovery heat exchanger 17 (which can be a plate heat exchanger or a shell-and-tube heat exchanger) to transfer excess heat to the cooling medium, thereby lowering the antifreeze temperature and maintaining it within the target temperature range to ensure efficient and stable engine operation.

[0021] Preferably, the specific process of the antifreeze circulation method is as follows, please refer to... Figure 1 , Figure 2 As shown: During the operation of the gas engine 12, the antifreeze is circulated by the antifreeze pump 13. The antifreeze circulates along the first path: the antifreeze first flows through the gas engine 12, absorbing the waste heat generated during its operation, causing its own temperature to rise. The control unit reads the temperature value from the temperature sensor installed in the gas engine, then compares this temperature value with a preset target temperature range. Based on the comparison result, it regulates the opening and closing of the valve assembly, thereby switching the flow direction of the antifreeze and maintaining the engine temperature within the optimal operating range. The specific control strategy is as follows: like Figure 2 As shown, when the unit starts up, if the monitored antifreeze temperature is lower than the preset target temperature range of 75-80℃, the control unit opens the first solenoid valve 14 and closes the second solenoid valve 15. In this state, the antifreeze circulates into the "self-circulation" path according to the second path. The complete flow sequence is as follows: after flowing out of the antifreeze pump 13, the antifreeze flows through the gas engine to continue absorbing waste heat, and then returns to the inlet of the antifreeze pump 13 through the opened first solenoid valve. This short-path circulation helps the antifreeze temperature rise quickly to the approximately 75-90℃ required for safe engine operation.

[0022] When the unit is operating normally and the antifreeze temperature reaches or exceeds 75-80℃ and continues to rise, the control unit opens the second solenoid valve 15 and closes the first solenoid valve 14. At this time, the antifreeze switches to the "heat dissipation circulation" path. The complete flow path is as follows: after flowing out of the antifreeze pump 13, the antifreeze flows through the gas engine 12 to absorb waste heat, and then enters the waste heat recovery heat exchanger 17 through the opened second solenoid valve 15. Here, the excess heat is transferred to the cooling water in the cooling water circulation system, reducing its own temperature, and finally returning to the inlet of the antifreeze pump 13. This path can stabilize the antifreeze temperature at around 75-90℃, ensuring efficient and stable system operation.

[0023] Preferably, the antifreeze circulation piping system further includes an expansion tank 16, connected at the highest point of the entire antifreeze circulation piping system: the expansion pipe of the expansion tank is connected to the pipeline between the outlet of the second solenoid valve and the inlet of the waste heat recovery heat exchanger. When the antifreeze in the system is insufficient due to evaporation or leakage, the expansion tank 16 can automatically replenish the antifreeze in the system to ensure the continuity and stability of the circulation.

[0024] Corresponding to the structure in the diagram: The specific connection structure of the antifreeze circulation system in this step is as follows: The output end of the antifreeze pump 13 is connected to the antifreeze inlet of the gas engine 12 through a pipe. A tee connector is connected to the antifreeze outlet of the gas engine 12. The two branch outlets of the tee connector are respectively connected to the inlets of the first solenoid valve 14 and the second solenoid valve 15 through pipes. The outlet of the second solenoid valve 15 is connected to the antifreeze inlet of the waste heat recovery heat exchanger 17 through a pipe, realizing heat exchange of the branch antifreeze. The antifreeze outlet of the waste heat recovery heat exchanger 17 and the outlet of the first solenoid valve 14 are converged into a single pipe through the tee and connected to the inlet of the antifreeze pump 13 through a pipe. The expansion pipe of the expansion tank 16 is connected to the connecting pipe between the outlet of the second solenoid valve 15 and the inlet of the waste heat recovery heat exchanger 17, used to replenish antifreeze and balance system pressure.

[0025] The cooling water circulation process specifically includes the following steps: Cooling water is driven by cooling water pump 19 to flow in the cooling water circulation loop, and the flow path of the cooling water in the cooling water circulation loop is adjusted by the flow direction control component. The cooling water circulation process includes a heat recovery process, which involves controlling the cooling water to flow sequentially through plate heat exchanger 3 and waste heat recovery heat exchanger 17, respectively, to exchange heat with the refrigerant of the system and the antifreeze of the engine, absorbing heat from the refrigerant and antifreeze and being heated. Then the heated cooling water is stored in hot water storage tank 18. After the cooling water flows out of the hot water storage tank after the heat recovery process, it is controlled by the flow direction control component to perform either a heat dissipation mode or a de-icing mode operation. During the heat dissipation mode operation, the cooling water in the hot water storage tank 18 is guided to the cooling tower 21 to release heat to the environment.

[0026] During the de-icing mode operation, the cooling water in the hot water storage tank 18 is guided to the de-icing channel in the evaporator 10, using its heat to provide a heat source for the de-icing process.

[0027] Preferably, combined with Figure 1 , Figure 2 and Figure 3 As shown, the specific implementation method of the cooling water circulation operation is as follows: The flow direction control component includes a third solenoid valve 20 and a fourth solenoid valve 22. The opening and closing states of these two solenoid valves are controlled by a program to switch the cooling water circulation path between heat dissipation mode and de-icing mode. The specific flow of the heat dissipation mode operation is described in conjunction with... Figure 2 as follows: During normal operation of the ice-making system, the control unit opens the third solenoid valve 20 and closes the fourth solenoid valve 22. At this time, the cooling water circulates under the drive of the cooling water pump 19 in the following sequence: the cooling water first flows out of the hot water storage tank 18 and flows through the cooling water pump 19 to obtain power; then, the cooling water flows through the opened third solenoid valve 20 and enters the cooling tower 21 for initial heat dissipation; afterwards, the cooling water flowing out of the cooling tower 21 enters the plate heat exchanger 3 and the waste heat recovery heat exchanger 17 in sequence, absorbing the condensation heat of the refrigerant in the plate heat exchanger 3 and absorbing the waste heat of the engine antifreeze in the waste heat recovery heat exchanger 17, thereby raising the water temperature to about 45℃-55℃; finally, the cooling water that has completed heat exchange flows back to the hot water storage tank 18 for storage.

[0028] The specific process of the de-icing mode operation is combined with Figure 3 When the ice-making process is complete and de-icing is required, the control system opens the fourth solenoid valve 22 and closes the third solenoid valve 20. At this time, the warm water stored in the hot water storage tank 18 at approximately 45℃-55℃ circulates under the drive of the cooling water pump 19, following this path: The cooling water first flows out of the hot water storage tank 18 and gains power from the cooling water pump 19; then, the cooling water flows through the opened fourth solenoid valve 22 and directly enters the de-icing channel inside the ice film 10; in the ice film 10, the warm water exchanges heat with the evaporator wall and the ice layer, causing the ice surface to melt and thus achieving de-icing; finally, the cooled water, after completing the heat exchange, flows back to the hot water storage tank 18 through the outlet of the de-icing channel. In this mode, the cooling water recycling system utilizes the waste heat stored in the system to provide the necessary heat for the de-icing process.

[0029] Preferably, this step further includes: post-de-icing treatment: After the de-icing process is completed, the cooling water pump 19, the third solenoid valve 20, and the fourth solenoid valve 22 are turned off to stop the cooling water circulation. Subsequently, the drain valve 23 on the cooling water circulation loop connected between the fourth solenoid valve and the ice film is opened to drain the water remaining in the de-icing channel of the ice film 10, so as to prevent the residual water in the channel from freezing and causing blockage when the next refrigeration cycle begins.

[0030] In this step, the refrigerant and antifreeze exchange heat through plate heat exchanger 3 and waste heat recovery heat exchanger 17, turning the refrigerant into warm water at approximately 45℃-55℃, which is then stored in a water tank. The heat from plate heat exchanger 3 and waste heat recovery heat exchanger 17 is removed by cooling tower 21, and hot water from storage tank 18 can also be used for de-icing. This efficient use of waste heat generated by the system for de-icing, while ensuring normal system operation, improves the system's energy efficiency. Cooling water circulation is initiated before unit operation to prevent the system's heat from being trapped and affecting normal system operation.

[0031] Referring to the attached diagram, the cooling water circulation system structure for achieving cooling water circulation can be specifically described as follows: The outlet end of the cooling water pump 19, which serves as the circulation power source, is connected to a tee joint via a pipe. The two branches of the tee joint are respectively connected to the inlets of the third solenoid valve 20 and the fourth solenoid valve 22 via pipes. Specifically, the outlet of the third solenoid valve 20 is connected to the inlet end of the cooling tower 21 via a pipe. The outlet end of the cooling tower 21 is then connected to the cooling water inlets of the plate heat exchanger 3 and the waste heat recovery heat exchanger 17 via pipes. The cooling water outlet of the waste heat recovery heat exchanger 17 is then connected to the inlet end of the hot water storage tank 18 via a pipe. The outlet of the fourth solenoid valve 22 is connected to the inlet end of the de-icing channel built into the ice film 10 via a pipe. The outlet end of this de-icing channel is connected to the hot water storage tank 18 via a pipe. The outlet end of the hot water storage tank 18 is connected to the inlet end of the cooling water pump 19 via a pipe.

[0032] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and, without departing from the spirit of the invention, devise structural methods and embodiments similar to this technical solution in terms of component shape and connection method without creative design, all such embodiments should fall within the protection scope of the present invention.

Claims

1. A method for operating a gas-fired internal combustion engine-driven direct-cooling block ice-making and de-icing unit, characterized in that: This includes the refrigerant circulation process, the antifreeze circulation process, and the cooling water circulation process; The refrigerant cycle specifically includes the following steps: A power unit drives a compression mechanism to provide power for the refrigerant cycle. Low-temperature, low-pressure gaseous refrigerant is drawn in and compressed by the compression mechanism, transforming it into high-temperature, high-pressure gaseous refrigerant. This high-temperature, high-pressure gaseous refrigerant then enters an oil separation mechanism to separate out any entrained lubricating oil before entering a condensation mechanism. There, it exchanges heat with the cooling medium and is condensed into a medium-temperature, high-pressure liquid refrigerant. This medium-temperature, high-pressure liquid refrigerant flows through a fluid processing component located downstream of the condensation mechanism for further processing. It is then throttled by a throttling mechanism, transforming into a low-temperature, low-pressure liquid refrigerant. The throttled, low-temperature, low-pressure liquid refrigerant enters an evaporation mechanism, where it exchanges heat with the cooling water, absorbing heat and evaporating into a low-temperature, low-pressure gaseous refrigerant. The gaseous refrigerant exiting the evaporation mechanism then enters a gas-liquid separation mechanism to separate any entrained liquid refrigerant. The separated gaseous refrigerant returns to the suction port of the compression mechanism, completing one refrigerant cycle. The antifreeze circulation process includes the following steps: Antifreeze is circulated through a cooling system to pass through the power unit and absorb the waste heat generated during the operation of the power unit. The temperature of the antifreeze is monitored in real time by a temperature sensor. A control unit controls the opening and closing of the valve assembly in the cooling system based on the comparison between the real-time temperature of the antifreeze and the preset target temperature range, thereby switching the flow path of the antifreeze. When the temperature of the antifreeze is lower than the preset target temperature range, the antifreeze is controlled to circulate along the first path, so that it flows through the power unit to quickly heat up to the target temperature range. When the temperature of the antifreeze reaches or exceeds the preset target temperature range, the antifreeze is controlled to switch to the second path, so that it flows through the waste heat recovery heat exchanger (17) to transfer excess heat to the cooling medium in the waste heat recovery heat exchanger (17), thereby causing the temperature of the antifreeze to drop and be maintained within the target temperature range. The cooling water circulation process specifically includes the following steps: Cooling water is driven by a cooling water pump (19) to flow in the cooling water circulation loop, and the flow path of the cooling water in the cooling circulation loop is adjusted by the flow direction control component; the cooling water circulation process includes a heat recovery process, which includes controlling the cooling water to flow sequentially through a plate heat exchanger (3) and a waste heat recovery heat exchanger (17), respectively exchanging heat with the refrigerant of the system and the antifreeze of the engine, absorbing heat from the refrigerant and antifreeze and being heated; then the heated cooling water is stored in a hot water storage tank (18); after the cooling water flows out of the hot water storage tank (18) after the heat recovery process, it is controlled by the flow direction control component to perform either a heat dissipation mode operation process or a de-icing mode operation process: During the heat dissipation mode operation, the cooling water in the hot water storage tank (18) is guided to the cooling tower (21) to release heat to the environment; During the de-icing mode operation, the cooling water in the hot water storage tank (18) is guided to the de-icing channel in the evaporator (10) to use its heat to provide a heat source for the de-icing process.

2. The operating method of a gas-fired internal combustion engine driven direct-cooling block ice-making and de-icing unit according to claim 1, characterized in that: The power unit is a gas engine (12), the compression mechanism is an open compressor (1), the oil separation mechanism is an oil separator (2), the condensation mechanism is a plate heat exchanger (3), the fluid handling assembly includes a one-way valve (4) connected in sequence between the condensation mechanism and the throttling mechanism to prevent refrigerant backflow, a liquid storage tank (5) for storing excess refrigerant and stabilizing system pressure, a dryer filter (6) for adsorbing moisture, a liquid supply solenoid valve (7) for controlling the on / off of liquid refrigerant, and a sight glass (8) for observing the refrigerant state, the throttling mechanism is an expansion valve (9), the evaporation mechanism is an ice film (10), and the gas-liquid separation mechanism is a gas-liquid separator (11).

3. The operating method of a gas-fired internal combustion engine driven direct-cooling block ice-making and de-icing unit according to claim 1, characterized in that: The control unit is a PLC or a microcontroller, and the expansion valve (9) is a thermal expansion valve or an electronic expansion valve.

4. The operating method of the gas-fired internal combustion engine driven direct-cooling block ice-making and de-icing unit according to claim 2 or 3, characterized in that: The specific process of the refrigerant circulation method is as follows: A gas engine (12) drives an open compressor (1). Low-temperature, low-pressure gaseous refrigerant with a temperature of -18℃ to 8℃ and a pressure of 0.1MPa to 0.16MPa is drawn in through the suction port of the open compressor. After compression, it becomes a high-temperature, high-pressure gaseous refrigerant with a temperature of 60℃ to 75℃ and a pressure of 1.0MPa to 1.3MPa, and is discharged through the compressor exhaust port. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor exhaust port enters an oil separator (2) to separate the lubricating oil. The refrigerant from the oil separator enters a plate heat exchanger (3) to exchange heat with the cooling water flowing through the plate heat exchanger (3). It is condensed into a medium-temperature, high-pressure liquid refrigerant with a temperature of 35℃ to 45℃ and a pressure of 0.89MPa to 1.2MPa. The medium-temperature, high-pressure liquid refrigerant passes through a one-way valve in sequence. The refrigerant is throttled through an expansion valve (9) and then converted into a low-temperature, low-pressure gaseous refrigerant with a temperature of -25°C to -15°C and a pressure of 0.1MPa to 0.16MPa. The throttled refrigerant enters the refrigerant channel of the ice film (10) and exchanges heat with the cooling water in the ice-making chamber of the ice film (10). It absorbs the heat of the water and causes the cooling water to freeze. The refrigerant itself evaporates into a low-temperature, low-pressure gaseous refrigerant with a temperature of -18°C to -8°C and a pressure of 0.1MPa to 0.16MPa. The gaseous refrigerant coming out of the evaporator enters the gas-liquid separator (11) to separate any possible liquid droplets. Finally, the separated gaseous refrigerant is led back to the suction port of the compressor to complete the entire refrigerant cycle.

5. The operating method of the gas-fired internal combustion engine driven direct-cooling block ice-making and de-icing unit according to claim 2 or 3, characterized in that: The specific process of the antifreeze circulation method is as follows: During the operation of the gas engine (12), the antifreeze is driven by the antifreeze pump (13) to circulate. The antifreeze circulates along the first path: The antifreeze first flows through the gas engine (12), absorbs the residual heat generated during its operation, and causes its own temperature to rise. The control unit reads the temperature value of the temperature sensor installed in the gas engine (12), and then compares the temperature value with the preset target temperature range. Based on the comparison result, the opening and closing of the valve assembly is adjusted to switch the flow direction of the antifreeze and maintain the engine temperature in the optimal operating range. The specific control strategy is as follows: When the unit starts up, if the detected antifreeze temperature is lower than the preset target temperature range of 75-80℃, the control unit opens the first solenoid valve (14) and closes the second solenoid valve (15). In this state, the antifreeze circulates into the "self-circulation" path according to the second path. The complete flow sequence is as follows: after the antifreeze flows out from the antifreeze pump (13), it flows through the gas engine (12) to continue absorbing residual heat, and then returns to the inlet of the antifreeze pump (13) through the opened first solenoid valve (14). When the unit is running normally and the antifreeze temperature reaches or exceeds 75-80℃ and continues to rise, the control unit opens the second solenoid valve (15) and closes the first solenoid valve (14). At this time, the antifreeze switches to the "heat dissipation circulation" path. The complete flow path is as follows: after the antifreeze flows out from the antifreeze pump (13), it flows through the gas engine (12) to absorb waste heat, and then enters the waste heat recovery heat exchanger (17) through the opened second solenoid valve (15). Here, the excess heat is transferred to the cooling water in the cooling water circulation system, so that its own temperature is reduced, and finally it returns to the inlet of the antifreeze pump (13).

6. The operating method of the gas-fired internal combustion engine driven direct-cooling block ice making and de-icing unit according to claim 5, characterized in that: The antifreeze circulation pipeline system includes an expansion tank (16), which is connected to the highest point of the entire antifreeze circulation pipeline system. That is, the expansion pipe of the expansion tank (16) is connected to the pipeline between the outlet of the second solenoid valve (15) and the inlet of the waste heat recovery heat exchanger (17).

7. The operating method of the gas-fired internal combustion engine driven direct-cooling block ice making and de-icing unit according to claim 5, characterized in that: The specific implementation method of the cooling water circulation operation method is as follows: The flow direction control component includes a third solenoid valve (20) and a fourth solenoid valve (22), wherein the specific process of the heat dissipation mode operation is as follows: During normal operation of the ice-making system, the control unit opens the third solenoid valve (20) and closes the fourth solenoid valve (22). At this time, the cooling water is driven by the cooling water pump (19) and circulates in the following order: The cooling water first flows out from the hot water storage tank (18) and flows through the cooling water pump (19) to obtain power; then, the cooling water flows through the opened third solenoid valve (20) and enters the cooling tower (21) for initial heat dissipation; then, the cooling water flowing out from the cooling tower enters the plate heat exchanger (3) and the waste heat recovery heat exchanger (17) in sequence, absorbing the condensation heat of the refrigerant in the plate heat exchanger (3) and absorbing the waste heat of the engine antifreeze in the waste heat recovery heat exchanger (17), thereby raising the water temperature to about 45℃-55℃; finally, the cooling water that has completed the heat exchange flows back to the hot water storage tank (18) for storage. The specific process of the de-icing mode is as follows: When the ice-making process is completed and de-icing is required, the control system opens the fourth solenoid valve (22) and closes the third solenoid valve (20). At this time, the warm water stored in the hot water storage tank (18) at about 45℃-55℃ circulates in the following order under the drive of the cooling water pump (19): The cooling water first flows out of the hot water storage tank (18) and flows through the cooling water pump (19) to obtain power. Then, the cooling water flows through the opened fourth solenoid valve (22) and then directly enters the de-icing channel inside the ice film (10). In the ice film (10), the warm water exchanges heat with the evaporator wall and the ice layer, causing the ice layer surface to melt and thus achieving de-icing. Finally, the cooled water that has completed the heat exchange flows back to the hot water storage tank (18) through the outlet of the de-icing channel.

8. The operating method of the gas-fired internal combustion engine driven direct-cooling block ice making and de-icing unit according to claim 7, characterized in that: The de-icing mode working process includes the de-icing post-processing procedure: after the de-icing process is completed, the cooling water pump (19), the third solenoid valve (20) and the fourth solenoid valve (22) are turned off to stop the cooling water circulation; then, the drain valve (23) on the cooling water circulation loop connected between the fourth solenoid valve (22) and the ice film (10) is opened to drain the water remaining in the de-icing channel of the ice film (10).

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