External ice melting open type system with efficient cold storage and cold supply functions

Abstract

The utility model discloses an efficient cold storage and supply external ice melting open system which comprises an ice storage pool, a base load host machine, a plate heat exchanger, a dual-working-condition host machine and an external network circulating pump, a bypass pipeline is further arranged between a first electric control valve and the water inlet end of the ice storage pool, one end of the bypass pipeline is connected with a fifth pipeline section, and the other end of the bypass pipeline is connected with a second electric control valve. The other end of the bypass pipeline is connected with the water inlet end of the ice storage pool to form a branch of the fifth pipeline section, a second electric switch valve is arranged on the bypass pipeline, and a third electric switch valve is arranged on the fifth pipeline section. Compared with the prior art, the base-load host and the dual-working-condition host participate in cold accumulation together through valve switching under the cold accumulation working condition at night, so that the overall operation energy efficiency of the host is improved, and meanwhile, the utilization rate of the base-load host is also improved.

Description

Technical Field

[0001] This utility model relates to a district cooling system, and more particularly to an efficient cold storage and cooling open-type system for melting ice. Background Technology

[0002] District cooling systems are becoming an emerging choice for cooling urban building complexes in my country due to their efficient energy utilization, resulting in lower energy consumption for air conditioning systems and reduced pollutant emissions. District cooling systems are often designed in conjunction with cold storage technology, which can take advantage of peak-valley electricity price differences to reduce operating costs. It also has the ability to "shave peaks and fill valleys" in the power grid, improving grid stability and achieving emission reduction benefits for the grid.

[0003] Common existing ice storage technologies mainly include external ice melting, internal ice melting, and dynamic ice making. Among them, external ice melting systems, due to the direct contact between the high-temperature chilled water return from air conditioning and the ice, have a fast ice melting and cooling rate, a linear cooling curve, and are easy to control. They can quickly produce large quantities of low-temperature chilled water and allow for more flexible operation strategies, minimizing operating costs, and are widely used in district cooling systems. External ice melting systems can be further divided into open and closed types. In open systems, chilled water is cooled by the upstream unit before entering the ice pool, and then pumped from the ice pool to the user side by an external circulating water pump. There is no heat exchange with ice melting plate heat exchangers, resulting in lower chilled water supply temperatures. The initial investment, floor space, and system energy consumption are all reduced compared to closed systems. Relevant scholars have conducted extensive research on the cooling and heat exchange process of external ice melting systems using experimental and numerical simulation methods, focusing mainly on the ice melting mechanism of ice storage coils, ice layer thickness, and cooling rate. District cooling systems typically release ice at temperatures below 1.5°C. After the ice melting process, a large amount of chilled water at around 1.5°C remains in the ice pool, making it unusable for further cooling. Simultaneously, during nighttime ice storage, a dual-mode refrigeration unit cools the 1.5°C water to below 0°C using a low-temperature ethylene glycol solution (approximately -6°C) while simultaneously producing some ice. The entire ice storage and melting process suffers from low energy efficiency of the dual-mode refrigeration unit and the unusable low-temperature water (around 1.5°C) remaining in the ice pool after melting. There is a lack of research on this issue both domestically and internationally.

[0004] Existing open-type external melting ice cooling systems (systems) are as follows: Figure 1 As shown, the key components include: base-mounted main unit 1, dual-condition main unit 2, dual-condition main unit water-ethylene glycol plate heat exchanger 3 (hereinafter referred to as plate heat exchanger), balance pipe 16, base-mounted main unit cooling primary pump 4, plate heat exchanger cooling primary pump 5, ethylene glycol pump 6, electric regulating valves 7-8, electric on / off valves 9-11, external network circulation pump 12, constant pressure water supply device 13, cooling end 14, and ice storage tank 15. Figure 1 The main structure of ice storage pool 15 within the dashed line area is as follows: Figure 2As shown, it includes a heat exchange device 19, a first water distributor 21, and a second water distributor 22.

[0005] The system can be divided into daytime cooling mode and nighttime ice storage mode.

[0006] The daytime cooling operation includes ice storage tank cooling operation and refrigeration unit cooling operation.

[0007] 1) During the ice storage tank cooling operation, electric regulating valves 7-8 and electric switching valve 9 are open, while the others are closed. External circulating water pump 12 is on, and the remaining pumps (such as the primary cooling pump 4 of the base-load main unit) are off. After passing through the cooling supply end 14, the water temperature rises to 12.5℃ (assuming conditions). Part of the high-temperature return water flows through the pipeline containing electric regulating valve 7, and the other part flows through the pipeline containing electric regulating valve 8 into the ice storage tank 15 for cooling, ultimately ensuring that the inlet water temperature of the external circulating water pump 12 reaches the required temperature. The cooling process in the ice storage tank 15 is as follows: Figure 2 As shown, the ice melting process is divided into two stages. During the initial and middle stages of melting, when the ice in the ice pool has not completely melted, the high-temperature return water from the cooling system enters the ice storage tank 15 through the inlet of the first water distributor 21. The high-temperature return water mixes with the ice-water mixture in the ice storage tank. The ice absorbs heat and melts, keeping the water in the ice pool at a low temperature, and then flows along... Figure 2 The ice-melting and cooling process, as shown in the diagram, involves a water flow direction that propels the ice. Low-temperature water flows out from the inlet / outlet of the water distributor 22. Later in the ice-melting process, when the ice in the ice pool has almost melted, high-temperature water continues to enter and rapidly mixes with the low-temperature water in the ice pool, forming high-density water at 4°C. Since water density is highest at 4°C, this portion of 4°C cold water sinks to the bottom of the pool and flows along the distribution direction. It then flows rapidly from the bottom to the outlet of the ice pool, raising the water temperature at the inlet of the second water distributor 22. This ultimately leads to stratification of the ice storage pool water, with only a small portion of the cold water usable. When the outlet water temperature reaches a certain level (around 1.5°C), the ice-melting and cooling process in the ice storage pool ends. At this point, a large amount of low-temperature water remains above the ice pool and cannot be fully utilized.

[0008] 2) During the cooling operation of the refrigeration unit, electric regulating valve 7 and electric switching valve 11 are open, while electric regulating valve 8, electric switching valves 9 and 10 are closed. All water pumps (base unit cooling primary pump 4, plate heat exchanger cooling primary pump 5, and external network circulating water pump 12) are turned on. After passing through the cooling supply end 14, the water temperature rises to 12.5℃. The high-temperature return water is cooled down through the base unit 1 and plate heat exchanger 3 to reach the required temperature before being pumped to the user's cooling supply end by water pump 12.

[0009] During nighttime cold storage operation, electric regulating valves 8, 9, and 11 are closed, while electric regulating valve 7 and 10 are open. The plate heat exchanger's primary cooling pump 5 is closed, and water pumps 4, 6, and 12 are activated. The base-load main unit 1 is activated, delivering 5°C chilled water to the cooling end 14 via water pumps 4 and 12 to meet some of the user's nighttime cooling needs. The dual-mode main unit 2 is activated, and ethylene glycol pump 6 delivers a low-temperature ethylene glycol solution into the heat exchanger in the ice storage tank 15, cooling the water in the tank. The water in the ice storage tank changes from less than 1.5°C to 0°C and freezes. At the end of the ice storage process, the outlet temperature of the dual-mode main unit 2 reaches -5.6°C, and it begins to reduce its load. The average cooling efficiency of the dual-mode main unit 2 is relatively low. During the final stage of ice storage, the dual-mode refrigeration unit may experience surge, leading to severe vibration and noise in the refrigeration unit. In severe cases, this may damage critical components such as the compressor, bearings, shaft seals, impellers, and motors, shortening the equipment's service life and increasing the operational risks of the refrigeration unit. Utility Model Content

[0010] The purpose of this utility model is to provide an efficient external ice melting system for cold storage and cooling. The technical problem to be solved is to improve the overall operating energy efficiency of the system and increase the utilization rate of the base-mounted host.

[0011] To solve the above problems, this utility model adopts the following technical solution: an efficient open-type system for external ice melting and cooling, including an ice storage tank, a base-mounted main unit, a plate heat exchanger, a dual-condition main unit, and an external network circulation pump. The ice storage tank is equipped with a heat exchange device, a first water distributor, a second water distributor, and a cooling end. The inlet of the ice storage tank is connected to one end of a first electric regulating valve, and the outlet of the ice storage tank is connected to one end of a first electric switching valve. The other end of the first electric switching valve is divided into two paths: a first pipeline section is connected to one end of the external network circulation pump, and a second pipeline section is connected to one end of a second electric regulating valve. The outlet of the cooling end is divided into three paths, with the third pipeline section connecting the cooling first-stage pump to the plate heat exchanger via the plate heat exchanger. The water supply is connected in two ways. The fourth pipeline section is connected to the inlet of the base unit via the primary cooling pump of the base unit. The fifth pipeline section is directly connected to the outlet of the base unit and the outlet of the dual-condition unit, forming one line and then splitting into two lines. One line is connected to the other end of the first electric regulating valve, and the other line is connected to the other end of the second electric regulating valve. The inlet of the cooling supply is connected to the other end of the external network circulation pump. A bypass pipeline is also provided between the first electric regulating valve and the inlet of the ice storage tank. One end of the bypass pipeline is connected to the fifth pipeline section, and the other end is connected to the inlet of the ice storage tank, forming a branch of the fifth pipeline section. A second electric switch valve is provided on the bypass pipeline, and a third electric switch valve is provided on the fifth pipeline section.

[0012] Furthermore, the ice storage tank is equipped with a partition device that divides the ice storage tank into two areas. The top of the partition device is lower than the highest water level of the ice storage tank, so that the two areas are connected.

[0013] Furthermore, the separating device is disposed between the second water distributor and the adjacent heat exchange device.

[0014] Furthermore, the distance between the top of the separating device and the highest water level of the ice storage tank is between 0 and 150 mm.

[0015] Furthermore, the pressure resistance of the separating device is greater than the maximum water pressure of the ice storage tank.

[0016] Furthermore, the operating conditions of the external melting ice open system include daytime cooling supply and nighttime cold storage.

[0017] Furthermore, the daytime cooling operation includes ice storage tank cooling operation and refrigeration unit cooling operation. In the ice storage tank cooling operation, the first electric regulating valve, the second electric regulating valve, the first electric switching valve, and the third electric switching valve are open, while the second electric switching valve, the fourth electric switching valve, and the fifth electric switching valve are closed. The external network circulation pump is turned on, while the ethylene glycol pump, the base load unit cooling primary pump, and the plate heat exchanger cooling primary pump are turned off. After the cold water passes through the cooling end, the water temperature rises to the return water temperature tr. After the return water passes through the pipeline where the third electric switching valve is located, part of it passes through the pipeline where the second electric regulating valve is located, and the other part passes through the pipeline where the first electric regulating valve is located to enter the ice storage tank for cooling. Then, it flows out of the ice storage tank from the pipeline where the first electric switching valve is located. After the two parts of water are mixed, the water temperature at the inlet of the external network circulation pump is ensured to reach the required supply water temperature.

[0018] When the refrigeration unit is in cooling mode, the second electric regulating valve and the fourth electric switching valve are open, while the first electric switching valve, the first electric regulating valve, the fifth electric switching valve, the second electric switching valve, and the third electric switching valve are closed. The external network circulation pump, the glycol pump, the base-mounted main unit cooling primary pump, and the plate heat exchanger cooling primary pump are all open. After the chilled water passes through the cooling end, the water temperature rises to the return water temperature. The return water is cooled down through the base-mounted main unit and the plate heat exchanger to reach the required temperature, and then passes through the pipeline where the second electric regulating valve is located. Finally, it is delivered to the cooling end by the external network circulation pump.

[0019] Furthermore, the nighttime cold storage operation includes single cold storage operation and simultaneous cold storage and supply operation.

[0020] Furthermore, in the single-mode cold storage operation, the second electric regulating valve, the first electric switching valve, the fifth electric switching valve, and the second electric switching valve are open, while the first electric regulating valve, the fourth electric switching valve, and the third electric switching valve are closed. The plate heat exchanger cooling primary pump and the external network circulation pump are closed, while the ethylene glycol pump and the base unit cooling primary pump are turned on. The bypass pipeline is connected, the dual-mode main unit is turned on, and the ethylene glycol pump delivers low-temperature ethylene glycol solution into the ice storage coil of the heat exchange device in the ice storage tank to cool the water in the ice storage tank. The water in the ice storage tank passes through the second electric switching valve and the pipeline and first enters the base unit cooling primary pump to reach the nighttime base unit cold storage temperature. Then, the cold water enters the ice storage tank from the outlet through the second electric regulating valve and the first electric switching valve, and undergoes secondary heat exchange with the ice storage coil of the heat exchange device to cool down again until the water freezes. When the water temperature in the ice storage tank drops below a certain level, the base unit stops, and only the dual-mode main unit performs cold storage.

[0021] During the simultaneous storage and supply operation, the second electric regulating valve, the first electric switching valve, the fifth electric switching valve, and the second electric switching valve are open, while the first electric regulating valve, the fourth electric switching valve, and the third electric switching valve are closed. Except for the plate heat exchanger cooling primary pump which is closed, the external network circulation pump, the ethylene glycol pump, and the base-mounted main unit cooling primary pump are open. The bypass pipeline is connected, and the dual-condition main unit is activated. The ethylene glycol pump delivers low-temperature ethylene glycol solution into the ice storage coil of the heat exchanger in the ice storage tank, cooling the water in the ice storage tank. The water in the ice storage tank, after passing through the second electric switching valve pipeline and the bypass pipeline, first enters the base-mounted main unit through the base-mounted main unit cooling primary pump for cooling to achieve nighttime base-mounted main unit cooling. After the water temperature is adjusted, some of the cold water enters the ice storage tank through the first electric switch valve, where it undergoes secondary heat exchange with the ice storage coil of the heat exchange device, cooling down again until the water freezes. The other part of the cold water is transported to the cooling end by the external network circulation pump after the second pipeline section where the second electric regulating valve is located, to meet the nighttime cooling needs of some users. When the water temperature in the ice storage tank drops below the nighttime cooling temperature of the base unit, the base unit stops storing cold and only provides cooling. At this time, the first electric switch valve and the second electric switch valve are closed. The high-temperature return water at the cooling end is transported to the cooling end by the external network circulation pump after passing through the first-stage cooling pump of the base unit and the cooling of the base unit, and then through the second pipeline section where the second electric regulating valve is located.

[0022] Compared with the prior art, this utility model connects the inlet of the ice storage outlet to the fifth pipeline section directly connected to the cooling supply end by setting a bypass pipeline, and installing a second electric switch valve at the end of the bypass pipeline and a third electric switch valve at the end of the fifth pipeline section. This enables the base-load host and the dual-mode host to participate in the cold storage through valve switching during nighttime cold storage operation, thereby improving the overall operating efficiency of the host and increasing the utilization rate of the base-load host. Attached Figure Description

[0023] Figure 1 This is a connection diagram of the existing system.

[0024] Figure 2 This is a schematic diagram of the existing ice storage tank.

[0025] Figure 3 This is a connection diagram of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the ice storage tank of this utility model. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0028] In this utility model, the end from which water enters the pipeline is referred to as the front end, and the end from which water exits is referred to as the end end.

[0029] like Figure 3As shown, this utility model discloses an efficient open-type system for external ice melting and cooling, including a base-mounted main unit 1, a dual-condition main unit 2, a dual-condition main unit water-ethylene glycol plate heat exchanger (hereinafter referred to as plate heat exchanger) 3, an ice storage tank 15, and a cooling supply end 14. The inlet of the ice storage tank 15 is connected to the end of a first electric regulating valve 8 via a pipe, and the outlet of the ice storage tank 15 is connected to the front end of a first electric switching valve 9 via a pipe. The end of the first electric switching valve 9 is divided into two branches, namely the first... Pipeline section 23 and second pipeline section 24 are connected. Pipeline section 23 connects to the front end of the external network circulation pump 12, and second pipeline section 24 connects to the end of the second electric regulating valve 7. The outlet of the cooling end 14 is divided into three lines: third pipeline section 25, fourth pipeline section 26, and fifth pipeline section 27. Plate heat exchanger cooling primary pump 5 and plate heat exchanger 3 are installed sequentially from the front end to the end on third pipeline section 25. Base-loaded main unit cooling primary pump 4 is installed sequentially from the front end to the end on fourth pipeline section 26. The base-mounted host 1, the end of the fifth pipeline section 27 directly connects with the ends of the third pipeline section 25 and the fourth pipeline section 26 to form one line, which then splits into two lines, namely the sixth pipeline section 28 and the seventh pipeline section 29. The end of the sixth pipeline section 28 is connected to the front end of the first electric regulating valve 8, and the end of the seventh pipeline section 29 is connected to the front end of the second electric regulating valve 7. A constant pressure water supply device 13 is also connected to the end of the first pipeline section 23. A heat exchange device 19 is provided in the ice storage tank 15, and the outlet of the heat exchange device 19... The pipeline is divided into two sections: the eighth pipe section 30 and the ninth pipe section 31. The end of the eighth pipe section 30 is connected to the ethylene glycol outlet of the plate heat exchanger 3. The ninth pipe section 31 is equipped with an ethylene glycol pump 6 and a dual-mode main unit 2 from the front end to the end. The ethylene glycol inlet of the plate heat exchanger 3 and the end of the ninth pipe section 31 are combined into one line and then connected to the inlet of the heat exchange device 19 through the fifth electric switching valve 10. A fourth electric switching valve 11 is installed on the pipe at the ethylene glycol inlet of the plate heat exchanger 3. Figure 4 As shown, the ice storage tank 15 is equipped with a heat exchange device 19, a first water distributor 21, and a second water distributor 22. The second water distributor 22 is connected to the outlet end of the ice storage tank 15, and the first water distributor 21 is connected to the inlet end of the ice storage tank 15. The heat exchange devices 19 are arranged in an array in the ice storage tank 15 and are connected in sequence. The above part is the conventional connection method in the prior art. The improvement is in the following part:

[0030] A bypass pipe 18 is provided between the first electric regulating valve 8 and the inlet end of the ice storage tank 15. One end of the bypass pipe 18 is connected to the fifth pipe section 27, and the other end is connected to the inlet end of the ice storage tank 15, forming a branch of the fifth pipe section 27. A second electric switch valve 16 is provided on the bypass pipe 18, and a third electric switch valve 17 is provided at the end of the fifth pipe section 27.

[0031] By adding a bypass pipeline 18 and installing a second electric switch valve 16 and a third electric switch valve 17, the base-load main unit can also participate in partial cold storage during nighttime cold storage operation through the control of the two electric switch valves. This enables the dual-mode main unit to operate in cold storage at a higher ethylene glycol solution temperature. The main unit's COP is significantly improved compared to conventional ice storage operation, resulting in more efficient and energy-saving operation. This improves the overall operating efficiency of the ice storage system and also increases the utilization rate of the base-load main unit.

[0032] like Figure 4 As shown, based on the above structure, the ice storage tank 15 is provided with a dividing device 20 that divides the ice storage tank 15 into two areas, left and right. The top of the dividing device 20 is lower than the highest water level of the ice storage tank 15, so that the two areas are connected at the upper end. Specifically, the dividing device 20 is set between the second water distributor 22 and the adjacent heat exchange device 19, thereby dividing the ice storage tank 15 into a left outlet area and a right mixing area. The dividing device 20 is set to prevent high temperature water from directly entering the outlet water distributor during ice melting and cooling, prolonging the time that the ice pool outlet water temperature is kept at a low temperature, thereby fully tapping the cooling potential of the ice pool after the release of cold and improving the overall cooling efficiency of the system.

[0033] In this invention, the distance between the top of the separating device 20 and the highest water level of the ice storage tank 15 is between 0 and 150 mm; when it is 0, the water flows through the power generated by the pump.

[0034] The pressure resistance of the separation device 20 is greater than the maximum water pressure of the ice storage tank, and it can be made of materials such as concrete that meet the strength requirements.

[0035] The operating conditions of this utility model can be divided into daytime cooling supply and nighttime ice storage.

[0036] The daytime cooling operation includes ice storage tank cooling operation and refrigeration unit cooling operation.

[0037] 1) During the ice storage tank cooling operation, the first electric regulating valve 8, the second electric regulating valve 7, the first electric switching valve 9, and the third electric switching valve 17 are open, while the remaining valves (the second electric switching valve 16, the fourth electric switching valve 11, and the fifth electric switching valve 10) are closed. The external network circulation pump 12 is on, while the remaining water pumps (the ethylene glycol pump 6, the base-load main unit cooling primary pump 4, and the plate heat exchanger cooling primary pump 5) are closed. After passing through the cooling supply end 14, the water temperature of the chilled water rises to the return water temperature tr (e.g., 12.5℃). The high-temperature return water passes through the pipeline where the third electric switching valve 17 is located. Part of it passes through the pipeline where the second electric regulating valve 7 is located, and the other part passes through the pipeline where the first electric regulating valve 8 is located to enter the ice storage tank 15 for cooling. Then, it flows out of the ice storage tank 15 from the pipeline where the first electric switching valve 9 is located. After the two parts of water are mixed, the water temperature at the inlet of the external network circulation pump 12 is finally guaranteed to reach the required supply water temperature ts (e.g., 2.5℃). The ice storage pool 15 is divided into two stages for melting and releasing ice:

[0038] Stage 1 of the ice storage tank melting and cooling operation: When the ice storage tank 15 begins to melt, the water flows from the first water distributor 21 to the second water distributor 22. The high-temperature return water mixes with the ice-water mixture in the ice storage tank 15. The ice absorbs heat and melts, keeping the water in the ice storage tank at a low temperature, and then flows along... Figure 4 The water flow direction shown in the diagram promotes ice melting and cooling. Low-temperature water flows out from the second water distributor 22. At this stage, the ice melting and cooling method is no different from that of a conventional external ice melting system.

[0039] Stage 2 of the ice storage tank's ice melting and cooling operation: When the ice in the ice storage tank has almost melted in the later stages of ice melting, if high-temperature water continues to enter the ice storage tank, it will quickly mix with the low-temperature water in the ice storage tank to form high-density water at 4°C. Since the density of water is greatest at 4°C, this part of 4°C cold water sinks to the bottom of the tank and flows along the water distribution direction at the bottom of the tank, and then flows quickly from the bottom of the tank to the position of the second water distributor 22. Due to the presence of the separator 20, this part of 4°C high-density water is prevented from flowing directly out of the second water distributor 22, but instead accumulates continuously at the bottom of the tank. At the same time, since the density of water with even lower temperature is less than that of water at 4°C, there is still a large amount of low-temperature water in the upper part of the tank. Under the action of the separator 20, this part of low-temperature water can enter the outlet area from the mixing area through the connecting channel and flow out from the second water distributor 22. Cooling will stop when the outlet water temperature of the ice tank reaches the maximum supply water temperature tms (e.g., 5-7°C). This method can extend the time that the outlet water temperature of the ice tank remains at a low temperature, thereby fully tapping the cooling potential of the ice tank after ice melting. After the ice storage tank is no longer cooled, the water inside will continue to exchange heat due to the temperature difference until the temperature reaches a certain equilibrium, at which point the water temperature is greater than tms.

[0040] 2) During the cooling operation of the refrigeration unit, the second electric regulating valve 7 and the fourth electric switching valve 11 are open, while the remaining valves (first electric switching valve 9, first electric regulating valve 8, fifth electric switching valve 10, second electric switching valve 16, and third electric switching valve 17) are closed. All water pumps (external network circulation pump 12, ethylene glycol pump 6, base-loaded main unit cooling primary pump 4, and plate heat exchanger cooling primary pump 5) are open. After passing through the cooling supply end 14, the chilled water temperature rises to the return water temperature tr (e.g., 12.5℃). The high-temperature return water is cooled down through the base-loaded main unit 1 and the plate heat exchanger 3 to reach the required temperature, then passes through the pipeline where the second electric regulating valve 7 is located, and is finally delivered to the cooling supply end 14 by the external network circulation pump 12.

[0041] The nighttime cold storage operation includes both single cold storage operation and simultaneous cold storage and supply operation.

[0042] 1) In single-mode cold storage operation, the second electric regulating valve 7, the first electric switching valve 9, the fifth electric switching valve 10, and the second electric switching valve 16 are open, while the remaining valves (the first electric regulating valve 8, the fourth electric switching valve 11, and the third electric switching valve 17) are closed. The plate heat exchanger cooling primary pump 5 and the external network circulation pump 12 are closed, while the remaining water pumps (ethylene glycol pump 6 and the base-load main unit cooling primary pump 4) are open, and the bypass pipeline 18 is connected. In dual-mode operation, the main unit 2 is turned on, and the ethylene glycol pump 6 delivers low-temperature ethylene glycol solution into the ice storage coil of the heat exchange device 19 in the ice storage tank 15 to cool the water in the ice storage tank. Contrary to the daytime cooling operation, the water in the ice storage tank, after passing through the second electric switch valve 16 and pipeline 18, first enters the base unit cooling pump 4 to cool down to the nighttime base unit cooling temperature tyj (e.g., 4℃). Then, the chilled water enters the ice storage tank from the outlet through the second electric regulating valve 7 and the first electric switch valve 9, where it undergoes secondary heat exchange with the ice storage coil of the heat exchange device 19, further cooling until the water freezes. When the water temperature in the ice storage tank drops below tyj, the base unit 1 shuts down, and only the dual-mode unit 2 performs cooling.

[0043] 2) During the simultaneous storage and supply operation, the second electric regulating valve 7, the first electric switching valve 9, the fifth electric switching valve 10, and the second electric switching valve 16 are open, while the remaining valves (the first electric regulating valve 8, the fourth electric switching valve 11, and the third electric switching valve 17) are closed. Except for the plate heat exchanger cooling primary pump 5, which is closed, the remaining pumps (external network circulation pump 12, ethylene glycol pump 6, and base-load main unit cooling primary pump 4) are open, and the bypass pipeline 18 is connected. The dual-operation main unit 2 is turned on, and the ethylene glycol pump 6 delivers low-temperature ethylene glycol solution into the ice storage coil of the heat exchange device 19 in the ice storage tank 15 to cool the water in the ice storage tank. Contrary to the daytime cooling operation, the water in the ice storage tank 15 flows through the second electric switch valve 16 and the bypass pipe 18, first entering the base unit 1 via the base unit cooling primary pump 4 to cool down to the nighttime base unit cooling storage temperature tyj (e.g., 4℃). Then, some of the chilled water enters the ice storage tank 15 through the first electric switch valve 9, undergoing secondary heat exchange with the ice storage coil of the heat exchange device 19, further cooling until the water freezes. The remaining chilled water flows through the second electric regulating valve 7 in the second pipe section 24 and is then transported by the external network circulation pump 12 to the cooling end 14, meeting the nighttime cooling needs of some users. When the water temperature in the ice storage tank 15 drops below tyj, the base unit 1 stops storing cold water and only provides cooling. At this time, the first electric switch valve 9 and the second electric switch valve 16 are closed. The high-temperature return water from the cooling end 14 is cooled by the first-stage cooling pump 4 of the base host and the base host 1, and then transported to the cooling end 14 by the external network circulation pump 12 after passing through the second pipeline section 24 where the second electric regulating valve 7 is located.

[0044] This utility model has the following features:

[0045] (1) By adding a partition device 20 to the ice storage tank 15, the high temperature water is blocked from directly entering the outlet water distributor during ice melting and cooling, thus extending the time that the outlet water temperature of the ice tank remains at a low temperature, thereby fully tapping the cooling potential of the ice tank after the release of cold and improving the overall cooling efficiency of the system.

[0046] (2) By innovating the open-loop ice-melting system, a connecting bypass pipeline and a switching valve were added. Since the cold water in the ice storage tank is fully utilized during the daytime cooling period, the base-load main unit can also perform partial ice storage during the nighttime ice storage operation. The dual-mode main unit can operate at a higher ethylene glycol solution temperature for ice storage, and the main unit's COP will be significantly improved compared to the conventional ice storage operation, making the operation more efficient and energy-saving, and improving the overall operating efficiency of the ice storage system.

[0047] (3) Base load chillers are generally configured based on peak load. At night, the cooling load is smaller, and the base load chillers may be idle, resulting in relatively low utilization. This utility model utilizes the base load chiller for cold storage at night, thus improving the utilization rate of the base load chiller.

Claims

1. An efficient open-type system for storing and supplying cold-melting ice, comprising an ice storage tank (15), a base-mounted main unit (1), a plate heat exchanger (3), a dual-condition main unit (2), and an external network circulation pump (12). The ice storage tank (15) is equipped with a heat exchange device (19), a first water distributor (21), a second water distributor (22), and a cooling supply end (14). The inlet of the ice storage tank (15) is connected to one end of the first electric regulating valve (8), and the outlet of the ice storage tank (15) is connected to one end of the first electric switching valve (9). The other end of the first electric switching valve (9) is divided into two paths. The first pipeline section (23) is connected to one end of the external network circulation pump (12), and the second pipeline section (24) is connected to one end of the second electric regulating valve (7). The outlet of the cooling end (14) is divided into three paths. The third pipeline section (25) is connected to the inlet of the plate heat exchanger (3) through the plate heat exchanger cooling first-stage pump (5). The fourth pipeline section (26) is connected to the inlet of the base host (1) through the base host cooling first-stage pump (4). The fifth pipeline section (27) is directly connected to the outlet of the base host (1) and the double... The outlet of the working host (2) is divided into two paths after being connected to one path. One path is connected to the other end of the first electric regulating valve (8), and the other path is connected to the other end of the second electric regulating valve (7). The inlet of the cooling end (14) is connected to the other end of the external network circulation pump (12). The feature is that a bypass pipeline (18) is also provided between the first electric regulating valve (8) and the inlet of the ice storage tank (15). One end of the bypass pipeline (18) is connected to the fifth pipeline section (27), and the other end is connected to the inlet of the ice storage tank (15), forming a branch of the fifth pipeline section (27). A second electric switch valve (16) is provided on the bypass pipeline (18), and a third electric switch valve (17) is provided on the fifth pipeline section (27).

2. The high-efficiency cold storage and cooling external ice melting open system according to claim 1, characterized in that: The ice storage tank (15) is provided with a dividing device (20) that divides the ice storage tank (15) into two areas. The top of the dividing device (20) is lower than the highest water level of the ice storage tank (15), so that the two areas are connected.

3. The high-efficiency cold storage and cooling open-type system for external ice melting as described in claim 2, characterized in that: The separating device (20) is located between the second water distributor (22) and the adjacent heat exchange device (19).

4. The high-efficiency cold storage and cooling external ice melting open system according to claim 3, characterized in that: The distance between the top of the separating device (20) and the highest water level of the ice storage tank (15) is between 0 and 150 mm.

5. The high-efficiency cold storage and cooling external ice melting open system according to claim 4, characterized in that: The pressure resistance of the separation device (20) is greater than the maximum water pressure of the ice storage tank.

6. The high-efficiency cold storage and cooling external ice melting open system according to any one of claims 1-5, characterized in that: The operating conditions of the external melting ice open system include daytime cooling supply and nighttime cold storage.

7. The high-efficiency cold storage and cooling external ice melting open system according to claim 6, characterized in that: The daytime cooling operation includes ice storage tank cooling operation and refrigeration unit cooling operation. In ice storage tank cooling operation, the first electric regulating valve (8), the second electric regulating valve (7), the first electric switching valve (9), and the third electric switching valve (17) are open, the second electric switching valve (16), the fourth electric switching valve (11), and the fifth electric switching valve (10) are closed, the external network circulation pump (12) is turned on, and the ethylene glycol pump (6), the base-loaded main unit cooling primary pump (4), and the plate heat exchanger cooling primary pump are activated. When pump (5) is turned off, the cold water temperature rises to the return water temperature after passing through the cooling end (14). After the return water passes through the pipeline where the third electric switch valve (17) is located, part of it passes through the pipeline where the second electric regulating valve (7) is located, and the other part passes through the pipeline where the first electric regulating valve (8) is located to enter the ice storage tank (15) for cooling. Then it flows out of the ice storage tank (15) from the pipeline where the first electric switch valve (9) is located. After the two parts of water are mixed, the water temperature at the inlet of the external network circulation pump (12) reaches the required water supply temperature. When the refrigeration unit is in cooling operation, the second electric regulating valve (7) and the fourth electric switching valve (11) are open, and the first electric switching valve (9), the first electric regulating valve (8), the fifth electric switching valve (10), the second electric switching valve (16), and the third electric switching valve (17) are closed. The external network circulation pump (12), the ethylene glycol pump (6), the base-loaded main unit cooling primary pump (4), and the plate heat exchanger cooling primary pump (5) are all open. After the cold water passes through the cooling end (14), the water temperature rises to the return water temperature. The return water passes through the base-loaded main unit (1) and the plate heat exchanger (3) to cool down to the required temperature and then passes through the pipeline where the second electric regulating valve (7) is located. Finally, it is delivered to the cooling end (14) by the external network circulation pump (12).

8. The high-efficiency cold storage and cooling open-type system for external ice melting according to claim 6, characterized in that: The nighttime cold storage operation includes single cold storage operation and simultaneous cold storage and supply operation.

9. The high-efficiency cold storage and cooling external melting ice open system according to claim 8, characterized in that: In the single-condition cold storage operation, the second electric regulating valve (7), the first electric switching valve (9), the fifth electric switching valve (10), and the second electric switching valve (16) are open, the first electric regulating valve (8), the fourth electric switching valve (11), and the third electric switching valve (17) are closed, the plate heat exchanger cooling primary pump (5) and the external network circulation pump (12) are closed, the ethylene glycol pump (6) and the base-load main unit cooling primary pump (4) are open, the bypass pipeline (18) is connected, the dual-condition main unit (2) is open, and the ethylene glycol pump (6) delivers low-temperature ethylene glycol solution into the ice storage tank (15) and the heat exchange device (1). In the ice storage coil of 9), the water in the ice storage tank is cooled down. The water in the ice storage tank passes through the second electric switch valve (16) and the pipeline (18) and then enters the base host cooling first pump (4) to cool down to the nighttime base host cooling temperature. After that, the cold water enters the ice storage tank from the outlet of the ice storage tank through the second electric regulating valve (7) and the first electric switch valve (9) and exchanges heat with the ice storage coil of the heat exchange device (19) for a second time, and cools down again until the water freezes. When the water temperature in the ice storage tank drops below the specified value, the base host (1) stops and only the dual-condition host (2) performs the cooling. During the simultaneous storage and supply operation, the second electric regulating valve (7), the first electric switching valve (9), the fifth electric switching valve (10), and the second electric switching valve (16) are opened, while the first electric regulating valve (8), the fourth electric switching valve (11), and the third electric switching valve (17) are closed. Except for the plate heat exchanger cooling primary pump (5), the external network circulation pump (12), the ethylene glycol pump (6), and the base load host cooling primary pump (4) are turned on. The bypass pipeline (18) is connected, and the dual-condition host (2) is turned on. The ethylene glycol pump (6) delivers low-temperature ethylene glycol solution into the ice storage coil of the heat exchange device (19) in the ice storage tank (15) to cool the water in the ice storage tank. The water in the ice storage tank (15) passes through the second electric switching valve (16) pipeline and the bypass pipeline (18) and then enters the base load host (1) through the base load host cooling primary pump (4) to cool down to the nighttime base load. After the main unit's cold storage temperature is reached, some of the cold water enters the ice storage tank (15) through the first electric switch valve (9) and undergoes secondary heat exchange with the ice storage coil of the heat exchange device (19) to cool down again until the water freezes. Another part of the cold water is transported to the cooling end (14) by the external network circulation pump (12) after passing through the second pipeline section (24) where the second electric regulating valve (7) is located, to meet the nighttime cooling needs of some users. When the water temperature in the ice storage tank (15) drops below the nighttime cold storage temperature of the main unit, the main unit (1) stops cold storage and only provides cooling. At this time, the first electric switch valve (9) and the second electric switch valve (16) are closed. The high-temperature return water of the cooling end (14) is cooled by the first-stage cooling pump (4) of the main unit and the main unit (1) and then transported to the cooling end (14) by the external network circulation pump (12) after passing through the second pipeline section (24) where the second electric regulating valve (7) is located.

Images