A subway station phase change cold storage air conditioning system and a control method thereof

Abstract

The present application provides a metro station phase change cold storage air conditioning system and a control method thereof. The system comprises a water collector, a chilled water pump, a cold water unit, a first electric on-off valve V1, a first electric regulating valve VT1, a water distributor, a cooling water pump, a second electric on-off valve V2, a third electric on-off valve V3, a fourth electric on-off valve V4 and a cooling tower which constitute a cold supply unit. The system further comprises a second electric bidirectional regulating valve VT2, an electric bidirectional on-off valve V5, an electric bidirectional on-off valve V6 and a phase change cold storage tank which constitute a cold storage unit. Compared with the prior art, the method of the present application enables the system to store cold at night during the low electricity price period and release cold during the day during the high electricity price period, thereby achieving peak load shifting of the electricity used by the metro station air conditioner and improving economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of cold storage technology for subway stations, specifically relating to a phase change cold storage air conditioning system for subway stations and its control method. Background Technology

[0002] As a crucial component of subway stations for regulating station temperature, the ventilation and air conditioning system accounts for 30%-40% of the total energy consumption of a subway station, resulting in extremely high operating costs. During subway operating hours (6:30-23:00), the electrical load of the ventilation and air conditioning system is extremely high, while the electrical load drops significantly late at night. The difference in electrical load between these two time periods is substantial, indicating a mismatch between energy supply and demand time and load intensity.

[0003] To address the aforementioned issues, a cold storage technology has been proposed in the prior art to achieve "peak shaving and valley filling." While existing cold storage technologies do achieve "peak shaving and valley filling," they are limited by their structural characteristics and control methods, generally possessing only a single function of supplying or storing cold. The linkage capability between the cooling unit and the cold storage unit is poor, resulting in low economic efficiency. Summary of the Invention

[0004] This invention provides a phase change cold storage air conditioning system for subway stations and its control method, which solves the problems existing in the prior art.

[0005] In a first aspect, in order to achieve the above objectives, the present invention provides a phase change cold storage air conditioning system for subway stations, which has a built-in control and monitoring terminal for controlling valve bodies. The system of the present invention includes several chiller units, several chilled water pumps, several cooling towers, several cooling water pumps, water collectors, water distributors, phase change cold storage boxes, a first electric switching valve V1, a second electric switching valve V2, a third electric switching valve V3, a fourth electric switching valve V4, an electric bidirectional switching valve V5, an electric bidirectional switching valve V6, a first electric regulating valve VT1, and a second electric bidirectional regulating valve VT2.

[0006] The system includes a water collector inlet connected to the chilled water return end of the air conditioning unit; a chilled water pump inlet connected to the water collector outlet; a chiller unit comprising an evaporator and a condenser, with the evaporator inlet connected to the chilled water pump outlet; a first electric on / off valve V1 inlet connected to the evaporator outlet; a first electric regulating valve VT1 inlet connected to the first electric on / off valve V1 outlet; a water distributor inlet connected to the first electric regulating valve VT1 outlet, used to supply water to the air conditioning unit; a cooling water pump outlet connected to the condenser inlet; a second electric on / off valve V2 inlet connected to the condenser outlet; and a third electric on / off valve V3... The inlet of the cooling tower is connected to the outlet of the second electric switch valve V2; the outlet of the fourth electric switch valve V4 is connected to the inlet of the cooling water pump; the inlet of the cooling tower is connected to the outlet of the third electric switch valve V3, and the outlet of the cooling tower is connected to the inlet of the fourth electric switch valve V4; the phase change cold storage box includes a first inlet and a second inlet; the first inlet is connected to the connecting pipe of the first electric switch valve V1 and the first electric switch valve VT1 through the second electric bidirectional regulating valve VT2; the second inlet is connected to the outlet of the chilled water pump through the electric bidirectional switch valve V5; the second inlet is connected to the inlet of the chilled water pump through the electric bidirectional switch valve V6.

[0007] Through the above technical solution, the connection relationship between the water collector, chilled water pump, chiller unit, first electric switch valve V1, first electric regulating valve VT1, water distributor, cooling water pump, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4 and cooling tower constitutes the main cooling function, while the connection relationship between the second electric bidirectional regulating valve VT2, electric bidirectional switch valve V5, electric bidirectional switch valve V6 and phase change cold storage box has both cold storage and cold supply functions. The control and monitoring terminal can flexibly adjust the working status of the corresponding valve body, so that the entire system stores cold at night when the electricity price is low and releases cold during the daytime when the electricity price is high, thereby realizing peak shifting and valley filling of the power consumption of subway station air conditioning and improving economic efficiency.

[0008] Preferably, the chiller unit, chilled water pump, cooling tower and cooling water pump are in one-to-one correspondence in quantity.

[0009] Preferably, if the number of chiller units, chilled water pumps, cooling towers, and cooling water pumps is greater than one, multiple chiller units are connected in parallel with the pipelines corresponding to the first electric switch valve V1, multiple chiller units are connected in parallel with the pipelines corresponding to the second electric switch valve V2, multiple chilled water pumps are connected in parallel, multiple cooling towers are connected in parallel with the pipelines corresponding to the third electric switch valve V3, and multiple cooling towers are connected in parallel with the pipelines corresponding to the fourth electric switch valve V4; the number of chiller units, chilled water pumps, cooling towers, and cooling water pumps that are turned on and off corresponds one-to-one.

[0010] Preferably, the phase change cold storage box has multiple phase change cold storage modules built in; the multiple phase change cold storage modules are parallel to each other and spaced apart.

[0011] Preferably, the outer shell of the phase change cold storage box is made of metal or plastic; centrifugal glass wool is installed around the outside of the phase change cold storage box.

[0012] Preferably, the phase change cold storage module includes a phase change layer and a support layer. The phase change layer is embedded in the support layer. The phase change layer is made of inorganic hydrated salt, paraffin, or organic-inorganic composite phase change material. The support layer is made of metal plate or plastic shell. The phase change temperature of the phase change layer is 8℃-10℃.

[0013] Preferably, it also includes a flow sensor P, which is installed between the phase change cold storage box and the connecting pipeline of the second electric bidirectional regulating valve VT2, and the flow sensor P is communicatively connected to the control and monitoring terminal.

[0014] Preferably, the device further includes a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3, and a fourth temperature sensor T4, which are connected to the control and monitoring terminal. The temperature probe of the first temperature sensor T1 is installed in the first inlet and outlet connecting pipe of the phase change cold storage box, the temperature probe of the second temperature sensor T2 is installed in the second inlet and outlet connecting pipe of the phase change cold storage box, the temperature probe of the third temperature sensor T3 is installed in the phase change cold storage box, and the temperature probe of the fourth temperature sensor T4 is installed in the connecting pipe of the first electric switching valve V1 and the first electric regulating valve VT1.

[0015] Preferably, it also includes a differential pressure bypass device, through which the water collector is connected to the water distributor.

[0016] Preferably, it also includes a constant pressure water supply device, which is connected to a water collector.

[0017] Secondly, in order to control the aforementioned phase change cold storage air conditioning system in subway stations, the present invention provides a control method for the phase change cold storage air conditioning system in subway stations, comprising:

[0018] S1: Obtain the preset electricity price tier time period, cooling time period, and the set water temperature T of the phase change cold storage tank. ch,set First water supply set temperature T g,set1 Second water supply set temperature T g,set2 , Temperature difference △T set at the cold storage inlet and outlet W,set1 1. Set the temperature difference △T at the cooling inlet and outlet. W,set2 Target cold storage capacity Q ch,set Load forecast Q during peak electricity price periods peak ;

[0019] Among them, the electricity price tiers include flat electricity price period, peak electricity price period, peak electricity price period and off-peak electricity price period;

[0020] S2: Obtain the current water flow rate L of the phase change cold storage box and the first monitoring temperature T of the first temperature sensor T1. W,in The second temperature sensor T2 monitors the second temperature T. W,out The third temperature sensor T3 detects the temperature T. W and the fourth temperature sensor T4, the fourth monitored temperature T chiller,out ;

[0021] S3: If the current time is not during the cooling period, proceed to step S4; otherwise, proceed to step S7.

[0022] S4: If the current time is during off-peak electricity pricing period, proceed to step S5; otherwise, return to step S1.

[0023] S5: Current cold storage capacity Q ch Not less than the target cold storage capacity Q ch,set Or the second monitoring temperature T W,out With the first monitoring temperature T W,in The difference is less than the set temperature difference △T between the cold storage inlet and outlet. W,set1 If the condition is met, return to step S1; otherwise, proceed to step S6.

[0024] S6: Execute the refrigeration unit's cold storage mode when the fourth monitored temperature T... chiller,out Equal to the set temperature T of the cold storage water ch,set If necessary, return to step S1;

[0025] S7: If the current time is during peak electricity price period, proceed to step S8; if the current time is during peak electricity price period, proceed to step S13; if the current time is during flat electricity price period, proceed to step S9; if the current time is during off-peak electricity price period, proceed to step S14.

[0026] S8: Determine whether the phase change cold storage box has stopped supplying cooling on the same day. If yes, proceed to step S9; otherwise, proceed to step S10.

[0027] Among them, the initial value of the day when the phase change cold storage box stops supplying cold is not;

[0028] S9: Execute the refrigeration unit's independent cooling mode when the fourth monitored temperature T chiller,out Equal to the second water supply set temperature T g,set2 If necessary, return to step S1;

[0029] S10: Determine whether the combined cooling mode of the refrigeration unit and the phase change cold storage box has been started on the same day. If yes, proceed to step S11; otherwise, proceed to step S12.

[0030] The initial value for the day of the combined cooling mode of the refrigeration unit and the phase change cold storage box is no;

[0031] S11: Executes the combined cooling mode of the refrigeration unit and phase change cold storage box, when the second monitored temperature T... W,out and the first monitoring temperature T W,in Is the difference less than the set temperature difference △T between the cooling inlet and outlet? W,set2 Record and stop the phase change cold storage box cooling for the day, then proceed to step S9; otherwise, return to step S1.

[0032] S12: Execute the phase change cold storage box's independent cooling mode, when the second monitored temperature T... W,out Less than or equal to the first water supply set temperature T g,set1 If the condition is met, return to step S1; otherwise, proceed to step S11.

[0033] S13: Current cold storage capacity Q ch Greater than the load forecast value Q peak If the condition is met, proceed to step S8; otherwise, proceed to step S9.

[0034] S14: Current cold storage capacity Q ch Not less than the target cold storage capacity Q ch,set Or the second monitoring temperature T W,out With the first monitoring temperature T W,in The difference is less than the set temperature difference △T between the cold storage inlet and outlet. W,set1 If the condition is met, proceed to step S9; otherwise, proceed to step S15.

[0035] S15: Executes the simultaneous cooling and cold storage mode of the refrigeration unit. When the fourth monitored temperature T... chiller,out Equal to the set temperature T of the cold storage water ch,set If the time is right, return to step S1.

[0036] Specifically, the cold storage mode of the refrigeration unit includes:

[0037] Turn on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V6 and second electric bidirectional regulating valve VT2, and close the electric bidirectional switch valve V5 and the first electric regulating valve VT1.

[0038] The independent cooling mode of the refrigeration unit includes:

[0039] Turn on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4 and first electric regulating valve VT1, and close the fifth electric switch valve V5, electric bidirectional switch valve V6 and second electric bidirectional regulating valve VT2.

[0040] The combined cooling mode of the refrigeration unit and the phase change cold storage box includes:

[0041] Turn on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, fifth electric switch valve V5, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2, and close the electric bidirectional switch valve V6.

[0042] The independent cooling modes of phase change cold storage boxes include:

[0043] Turn on the chilled water pump, the fifth electric switch valve V5, the first electric regulating valve VT1, and the second electric bidirectional regulating valve VT2; turn off the chiller unit, cooling tower, cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, and the electric bidirectional switch valve V6.

[0044] The refrigeration unit can simultaneously supply cooling and store cold energy in the following modes:

[0045] Turn on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V6, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2, and close the fifth electric switch valve V5.

[0046] The present invention has at least the following advantages:

[0047] 1) Compared with existing technologies, the system of the present invention achieves peak shifting and valley filling of electricity consumption for subway station air conditioning by storing cold at off-peak electricity prices at night and releasing cold during peak electricity prices during the day, which has a significant effect on reducing air conditioning operating costs and alleviating grid pressure.

[0048] 2) Compared with the existing technology, the system of the present invention uses a phase change cold storage box with a relatively small volume, which can effectively reduce the footprint and save civil engineering costs.

[0049] 3) Compared with the prior art, the phase change cold storage box of the present invention eliminates the plate heat exchanger compared with the water tank of the conventional cold storage system, and adds multiple phase change cold storage modules inside, which has a stronger cold storage capacity. Furthermore, using the phase change cold storage box instead of the water tank can effectively reduce the risk of emptying and pressure on the conventional water cold storage system, which is more conducive to the stable operation of the system.

[0050] (4) Compared with the prior art, the control method matched with the system of the present invention can realize combined cooling supply by the refrigeration main unit and the phase-change cold storage tank, which can effectively reduce the designed capacity of the refrigeration main unit and lower the initial investment cost of the system. Moreover, the method of the present invention can also flexibly adjust the operation mode of the system of the present invention according to actual conditions, so as to meet the cooling supply demands of metro stations under different working conditions. Brief Description of the Drawings

[0051] To more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below show only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0052] Figure 1 is a schematic structural diagram of the phase-change cold storage air conditioning system for a metro station in the first embodiment of the present invention.

[0053] Reference numerals of the drawings: 1. Water chiller; 2. Chilled water pump; 3. Cooling tower; 4. Cooling water pump; 5. Water collector; 6. Water separator; 7. Differential pressure bypass device; 8. Phase-change cold storage tank; 81. Phase-change cold storage module; 9. Constant pressure water replenishing device. Detailed Description of the Embodiments

[0054] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of, not all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without making creative work shall fall within the protection scope of the present invention.

[0055] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0056] Embodiment 1

[0057] As shown in Figure 1As shown, this embodiment discloses a phase change cold storage air conditioning system for a subway station, which has a built-in control and monitoring terminal. The system includes a chiller unit 1, a chilled water pump 2, a cooling tower 3, a cooling water pump 4, a water collector 5, a water distributor 6, a differential pressure bypass device 7, a phase change cold storage box 8, a phase change cold storage module 81, a constant pressure water supply device 9, a first electric switch valve V1, a second electric switch valve V2, a third electric switch valve V3, a fourth electric switch valve V4, an electric bidirectional switch valve V5, an electric bidirectional switch valve V6, a first electric regulating valve VT1, and a second electric bidirectional regulating valve VT2.

[0058] The inlet of the water collector 5 is connected to the chilled water return end of the air conditioning unit, the inlet of the chilled water pump 2 is connected to the outlet of the water collector 5, the chiller unit 1 has an evaporator and a condenser built in, the inlet of the evaporator is connected to the outlet of the chilled water pump 2, the inlet of the first electric switch valve V1 is connected to the outlet of the evaporator, the inlet of the first electric regulating valve VT1 is connected to the outlet of the first electric switch valve V1, the inlet of the water distributor 6 is connected to the outlet of the first electric regulating valve VT1, the outlet of the cooling water pump 4 is connected to the inlet of the condenser, the inlet of the second electric switch valve V2 is connected to the outlet of the condenser, the inlet of the third electric switch valve V3 is connected to the outlet of the second electric switch valve V2, the outlet of the fourth electric switch valve V4 is connected to the inlet of the cooling water pump 4, the inlet of the cooling tower 3 is connected to the outlet of the third electric switch valve V3, and the outlet of the cooling tower 3 is connected to the inlet of the fourth electric switch valve V4.

[0059] Through the above technical solution, the connection relationship between the water collector 5, chilled water pump 2, chiller unit 1, first electric switch valve V1, first electric regulating valve VT1, water distributor 6, cooling water pump 4, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4 and cooling tower 3 plays the main role in refrigeration.

[0060] Furthermore, the phase change cold storage box 8 includes a first inlet and a second inlet. The first inlet is connected to the connecting pipe of the first electric switching valve V1 and the first electric regulating valve VT1 through the second electric bidirectional regulating valve VT2. The second inlet is connected to the outlet of the chilled water pump 2 through the electric bidirectional switching valve V5, and the second inlet is connected to the inlet of the chilled water pump 2 through the electric bidirectional switching valve V6.

[0061] Through the above technical solution, the connection relationship between the second electric bidirectional regulating valve VT2, the electric bidirectional switching valve V5, the electric bidirectional switching valve V6 and the phase change cold storage box 8 together has both cold storage and cold supply functions.

[0062] Compared to existing technologies, the control and monitoring terminal or unit staff of the system of this invention can flexibly adjust the working status of the corresponding valve body, switch the working mode of the cooling unit and the cold storage unit, realize peak shifting and valley filling of the power consumption of the subway station air conditioning, thereby improving economic efficiency.

[0063] In order to monitor the inlet and outlet water flow of the phase change cold storage box 8 in real time, the system of the present invention sets up a flow sensor P between the phase change cold storage box 8 and the connecting pipeline of the second electric bidirectional regulating valve VT2. The flow sensor P is connected to the control and monitoring terminal. When the inlet and outlet water flow of the phase change cold storage box 8 is monitored by the flow sensor P, it is transmitted to the control and monitoring terminal.

[0064] To achieve precise monitoring, the system further includes a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3, and a fourth temperature sensor T4. The temperature probe of the first temperature sensor T1 is installed in the first inlet / outlet connecting pipe of the phase change cold storage box 8; the temperature probe of the second temperature sensor T2 is installed in the second inlet / outlet connecting pipe of the phase change cold storage box 8; the temperature probe of the third temperature sensor T3 is installed inside the phase change cold storage box 8; and the temperature probe of the fourth temperature sensor T4 is installed in the connecting pipe between the first electric switching valve V1 and the first electric regulating valve VT1. All of these sensors are communicatively connected to a control and monitoring terminal, and temperature information from each corresponding location is transmitted to the control and monitoring terminal.

[0065] Preferably, the chiller unit 1, chilled water pump 23, cooling tower and cooling water pump 4 are in one-to-one correspondence in quantity.

[0066] To improve the load, cooling, and cold storage capacity of the system of the present invention, when the number of chiller unit 1, chilled water pump 2, cooling tower 3, and cooling water pump 4 is greater than one, chiller unit 1 is connected in parallel with the pipeline where the first electric switch valve V1 is located, chiller unit 1 is connected in parallel with the pipeline where the second electric switch valve V2 is located, multiple chilled water pumps 2 are connected in parallel, multiple cooling towers 3 are connected in parallel with the pipelines where the third electric switch valve V3 and the fourth electric switch valve V4 are located, and multiple cooling water pumps 4 are connected in parallel. The number of chiller unit 1, chilled water pump 2, cooling tower 3, and cooling water pump 4 are turned on and off in a one-to-one correspondence.

[0067] In this embodiment, the constant pressure water supply device 9 is connected to the water collector 5 through an expansion pipe so as to supply water to the water collector 5 when the water supply pressure of the water collector 5 is insufficient, so that the system of the present invention can operate normally under stable water pressure.

[0068] In this embodiment, the water collector 5 is connected to the water distributor 6 through the differential pressure bypass device 7, which is used to maintain a constant pressure difference between the water collector 5 and the water distributor 6, thereby enabling the system of the present invention to operate normally under stable water pressure.

[0069] Preferably, the outer shell of the phase change cold storage box 8 is made of metal or plastic, and centrifugal glass wool is arranged around its outer perimeter to prevent heat loss into the environment. The phase change cold storage box 8 contains multiple phase change cold storage modules 81, which are parallel to each other and spaced apart, leaving a certain gap between them to form a water flow channel. Each phase change cold storage module 81 consists of a phase change layer and a support layer. The phase change layer is embedded within the support layer. The phase change layer is made of inorganic hydrated salt, paraffin, or organic-inorganic composite phase change material. The support layer is made of metal plate or plastic shell, and the phase change temperature of the phase change layer is selected to be 8℃-10℃.

[0070] Through the above technical solution, the internal structure of the phase change cold storage box 8 has been improved, resulting in better cold storage and insulation capabilities. Compared with existing technologies, this box has a relatively smaller volume, effectively reducing the floor space required and saving on construction costs.

[0071] Example 2

[0072] Based on Embodiment 1, the present invention incorporates a control method for a phase change cold storage air conditioning system in a subway station into its control and monitoring terminal. This method includes:

[0073] S1: Obtain the preset electricity price tier time period, cooling time period, and the set water temperature T of the phase change cold storage tank. ch,set First water supply set temperature T g,set1 Second water supply set temperature T g,set2 , Temperature difference △T set at the cold storage inlet and outlet W,set1 1. Set the temperature difference △T at the cooling inlet and outlet. W,set2 Target cold storage capacity Q ch,set Load forecast Q during peak electricity price periods peak .

[0074] In this embodiment, the electricity price tiers include flat electricity price periods, peak electricity price periods (morning and evening commuting peaks), peak electricity price periods, and off-peak electricity price periods.

[0075] S2: Obtain the current water flow rate L of the phase change cold storage box and the first monitoring temperature T of the first temperature sensor T1. W,in The second temperature sensor T2 monitors the second temperature T. W,out The third temperature sensor T3 detects the temperature T. W and the fourth temperature sensor T4, the fourth monitored temperature T chiller,out .

[0076] In this embodiment, the first monitored temperature T of the first temperature sensor T1 is... W,in The monitoring water temperature at the first inlet and outlet of the phase change cold storage box, and the second monitoring temperature T of the second temperature sensor T2. W,outThe monitoring water temperature at the second inlet and outlet of the phase change cold storage box, and the third monitoring temperature T of the third temperature sensor T3. W The fourth temperature sensor T4 monitors the temperature T of the water inside the phase change cold storage chamber. chiller,out This refers to the outlet water temperature of the evaporator in the chiller unit. Both the temperature and flow rate information mentioned above are received and processed by the control and monitoring terminal.

[0077] S3: If the current time is not during the cooling period, proceed to step S4; otherwise, proceed to step S7.

[0078] S4: If the current time is during off-peak electricity pricing period, proceed to step S5; otherwise, return to step S1.

[0079] S5: Current cold storage capacity Q ch Not less than the target cold storage capacity Q ch,set Or the second monitoring temperature T W,out With the first monitoring temperature T W,in The difference is less than the set temperature difference △T between the cold storage inlet and outlet. W,set1 If the condition is met, return to step S1; otherwise, proceed to step S6.

[0080] S6: Execute the refrigeration unit's cold storage mode when the fourth monitored temperature T... chiller,out Equal to the set temperature T of the cold storage water ch,set If the time is right, return to step S1.

[0081] Specifically, the cold storage mode of the refrigeration unit includes: turning on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V6, and second electric bidirectional regulating valve VT2, and turning off the electric bidirectional switch valve V5 and the first electric regulating valve VT1.

[0082] With the above technical solution, when the water supply to the collection tank and distribution tank stops, the cooling supply stops, and the chiller's cold storage mode is activated. The cooling water from the chiller's condenser outlet flows sequentially through the second electric switch valve V2 and the third electric switch valve V3 before entering the cooling tower for cooling, and then returns to the chiller's condenser via the fourth electric switch valve V4 and the cooling water pump. Meanwhile, the chilled water from the chiller's evaporator outlet flows through the first electric switch valve V1 and the second electric bidirectional regulating valve VT2 before entering the phase change cold storage tank. This cools and solidifies the phase change material (phase change layer) within the phase change cold storage module, storing the cold energy. The chilled water from the phase change cold storage tank outlet flows back to the chiller's evaporator via the electric bidirectional switch valve V6 and the chilled water pump. Compared to existing technologies, this method is more efficient when the current time is during off-peak electricity pricing and the current cold storage capacity Q... ch When the cold is insufficient, the refrigeration unit will activate the cold storage mode to achieve automatic cold storage in the phase change cold storage box.

[0083] S7: If the current time is during the peak electricity price period, proceed to step S8; if the current time is during the peak electricity price period, proceed to step S13; if the current time is during the flat electricity price period, proceed to step S9; if the current time is during the off-peak electricity price period, proceed to step S14.

[0084] S8: Determine whether the phase change cold storage box has stopped supplying cooling on the same day. If yes, proceed to step S9; otherwise, proceed to step S10.

[0085] It should be noted that if the phase change cold storage box has stopped supplying cooling on that day, it means that the cold storage capacity of the phase change cold storage box has been exhausted, and subsequent steps will only be cooled by the refrigeration unit. If the phase change cold storage box has not stopped supplying cooling on that day, it means that the cold storage capacity of the phase change cold storage box is sufficient and can be used for cooling during subsequent subway operation periods.

[0086] S9: Execute the refrigeration unit's independent cooling mode when the fourth monitored temperature T chiller,out Equal to the second water supply set temperature T g,set2 If the time is right, return to step S1.

[0087] Specifically, the refrigeration unit's independent cooling mode includes: turning on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4 and first electric regulating valve VT1, and closing the fifth electric switch valve V5, electric bidirectional switch valve V6 and second electric bidirectional regulating valve VT2.

[0088] Through the above technical solution, when the refrigeration unit operates in independent cooling mode during subway operation, the cooling water from the condenser outlet of the chiller unit flows sequentially through the second electric switch valve V2 and the third electric switch valve V3 before entering the cooling tower for cooling. It then returns to the condenser of the chiller unit via the fourth electric switch valve V4 and the cooling water pump. The chilled water from the evaporator outlet of the chiller unit flows sequentially through the first electric switch valve V1, the first electric regulating valve VT1, and the water distributor to supply chilled water to the air conditioning units. The return water from the air conditioning units is returned to the evaporator of the chiller unit via the water collector and the chilled water pump. This achieves independent cooling for the refrigeration unit in the system of this invention, thus cooling the thermal environment of the subway station.

[0089] S10: Determine whether the combined cooling mode of the refrigeration unit and the phase change cold storage box has been started on the same day. If yes, proceed to step S11; otherwise, proceed to step S12.

[0090] It should be noted that the initial value of the above-mentioned combined cooling mode of the refrigeration unit and phase change cold storage box needs to be determined by the unit personnel or the control and monitoring terminal based on the initial value.

[0091] S11: Executes the combined cooling mode of the refrigeration unit and phase change cold storage box, when the second monitored temperature T... W,out and the first monitoring temperature T W,in Is the difference less than the set temperature difference △T between the cooling inlet and outlet? W,set2 If the phase change cold storage box is stopped and the cooling supply is stopped for the day, proceed to step S9; otherwise, return to step S1.

[0092] Specifically, the combined cooling mode of the refrigeration unit and the phase change cold storage box includes: turning on the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, fifth electric switch valve V5, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2, and turning off the electric bidirectional switch valve V6.

[0093] Through the above technical solution, during peak electricity pricing periods of subway operation, a combined cooling mode of the chiller and phase change cold storage box is implemented. Cooling water from the chiller unit's condenser outlet flows sequentially through the second electric switch valve V2 and the third electric switch valve V3 before entering the cooling tower for cooling. It then passes through the fourth electric switch valve V4 and the cooling water pump before returning to the chiller unit's condenser. The return water from the air conditioning unit flows through the water collector and the chilled water pump. Part of it flows through the fifth electric switch valve V5 and enters the phase change cold storage box for cooling, then flows back to the first electric regulating valve VT1 and the distributor to supply chilled water to the air conditioning unit. The other part returns to the chiller unit's evaporator for cooling. The chilled water from the chiller unit's evaporator outlet flows sequentially through the first electric switch valve V1, the first electric regulating valve VT1, and the distributor before supplying chilled water to the air conditioning unit. The flow rates of the first electric regulating valve VT1 and the second electric bidirectional regulating valve VT2 are determined according to the set temperature T. g,set2 To adjust. Compared with the prior art, the method of this invention realizes the combined cooling supply of the refrigeration unit and the phase change cold storage box.

[0094] S12: Execute the phase change cold storage box's independent cooling mode, when the second monitored temperature T... W,out Less than or equal to the first water supply set temperature T g,set1 If the condition is met, return to step S1; otherwise, proceed to step S11.

[0095] Specifically, the phase change cold storage box's independent cooling mode includes: turning on the chilled water pump, the fifth electric switch valve V5, the first electric regulating valve VT1, and the second electric bidirectional regulating valve VT2, and turning off the chiller unit, cooling tower, cooling water pump, the first electric switch valve V1, the second electric switch valve V2, the third electric switch valve V3, the fourth electric switch valve V4, and the electric bidirectional switch valve V6.

[0096] Through the above technical solution, during peak electricity price periods of subway operation and when the phase change cold storage box has sufficient cold storage capacity, the phase change cold storage box is used for independent cooling. The chilled water from the outlet of the phase change cold storage box flows through the second electric bidirectional regulating valve VT2, the first electric regulating valve VT1 and the water distributor to supply chilled water to the air conditioning unit. The return water of the chilled water from the air conditioning unit flows through the water collector, the chilled water pump and the fifth electric switch valve V5 in sequence before returning to the phase change cold storage box to be cooled. The above process is repeated to cool down the thermal environment of the subway station.

[0097] S13: Current cold storage capacity Q ch Greater than the load forecast value Q peak If the condition is met, proceed to step S8; otherwise, proceed to step S9.

[0098] It should be noted that during the cooling process, the phase change cold storage box's own cold storage capacity will gradually decrease. When it decreases to less than the predicted load value Q, it will eventually reach its maximum capacity. peak If the phase change cold storage box has insufficient cold storage capacity to provide cooling, proceed to step S9; otherwise, proceed to step S8.

[0099] S14: Current cold storage capacity Q ch Not less than the target cold storage capacity Q ch,set Or the second monitoring temperature T W,out With the first monitoring temperature T W,in The difference is less than the set temperature difference △T between the cold storage inlet and outlet. W,set1 If the condition is met, proceed to step S9; otherwise, proceed to step S15.

[0100] Through the above technical solution, step S14 can make a reasonable judgment on off-peak electricity price periods and improve the efficiency of cold storage energy.

[0101] S15: Executes the simultaneous cooling and cold storage mode of the refrigeration unit. When the fourth monitored temperature T... chiller,out Equal to the set temperature T of the cold storage water ch,set If the time is right, return to step S1.

[0102] Specifically, start the chiller unit, chilled water pump, cooling tower, cooling water pump, first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V6, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2, and close the fifth electric switch valve V5.

[0103] Through the above technical solution, during off-peak electricity pricing periods, the chiller operates in a simultaneous cooling and cold storage mode. At this time, chilled water from the chiller unit's evaporator outlet flows through the first electric switching valve V1, and a portion flows through the second electric bidirectional regulating valve VT2 into the phase change cold storage tank. This cools and solidifies the phase change material in the phase change cold storage module, storing the cooling capacity within the material. Chilled water in the phase change cold storage tank flows through the electric bidirectional switching valve V6 and the chilled water pump back to the chiller unit's evaporator. A portion flows through the first electric regulating valve VT1 and the water distributor to supply chilled water to the air conditioning units. The return chilled water from the air conditioning units flows through the water collector and the chilled water pump back to the chiller unit's evaporator. The flow rates of the first electric regulating valve VT1 and the second electric bidirectional regulating valve VT2 are adjusted according to the cooling demand of the air conditioning units.

[0104] In summary, the specific operating modes that the method of the present invention can flexibly schedule are shown in the following table:

[0105] Table 1

[0106]

[0107]

[0108] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0109] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A control method for a phase change cold storage air conditioning system in a subway station, characterized in that, Used to control a phase change cold storage air conditioning system for a subway station; The subway station phase change cold storage air conditioning system has a built-in control and monitoring terminal for controlling the valve body, including several chiller units (1), several chilled water pumps (2), several cooling towers (3), several cooling water pumps (4), water collector (5), water distributor (6), phase change cold storage box (8), first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V5, electric bidirectional switch valve V6, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2; The inlet of the water collector (5) is connected to the chilled water return end of the air conditioning unit; the inlet of the chilled water pump (2) is connected to the outlet of the water collector (5); the chiller unit (1) includes an evaporator and a condenser, and the inlet of the evaporator is connected to the outlet of the chilled water pump (2); the inlet of the first electric switching valve V1 is connected to the outlet of the evaporator; the inlet of the first electric regulating valve VT1 is connected to the outlet of the first electric switching valve V1; the inlet of the water distributor (6) is connected to the outlet of the first electric regulating valve VT1. The water distributor (6) is used to supply water to the air conditioning unit; the outlet of the cooling water pump (4) is connected to the inlet of the condenser; the inlet of the second electric switch valve V2 is connected to the outlet of the condenser; the inlet of the third electric switch valve V3 is connected to the outlet of the second electric switch valve V2; the outlet of the fourth electric switch valve V4 is connected to the inlet of the cooling water pump (4); the inlet of the cooling tower (3) is connected to the outlet of the third electric switch valve V3, and the outlet of the cooling tower (3) is connected to the inlet of the fourth electric switch valve V4. The phase change cold storage box (8) includes a first inlet and a second inlet; the first inlet is connected to the first electric switching valve V1 and the connecting pipe of the first electric regulating valve VT1 through the second electric bidirectional regulating valve VT2; the second inlet is connected to the outlet of the chilled water pump (2) through the electric bidirectional switching valve V5; the second inlet is connected to the inlet of the chilled water pump (2) through the electric bidirectional switching valve V6. The phase change cold storage air conditioning system of the subway station also includes a flow sensor P, which is installed between the phase change cold storage box (8) and the second electric bidirectional regulating valve VT2 in the connecting pipeline, and the flow sensor P is communicatively connected to the control and monitoring terminal. The subway station phase change cold storage air conditioning system also includes a first temperature sensor T1, a second temperature sensor T2, a third temperature sensor T3, and a fourth temperature sensor T4, which are connected to the control and monitoring terminal. The temperature probe of the first temperature sensor T1 is installed in the first inlet and outlet connecting pipe of the phase change cold storage box (8), the temperature probe of the second temperature sensor T2 is installed in the second inlet and outlet connecting pipe of the phase change cold storage box (8), the temperature probe of the third temperature sensor T3 is installed in the phase change cold storage box (8), and the temperature probe of the fourth temperature sensor T4 is installed in the connecting pipe of the first electric switching valve V1 and the first electric regulating valve VT1. The control method includes: S1: Obtain the preset electricity price tier period, cooling period, cold storage set water temperature Tch,set, first water supply set temperature Tg,set1, second water supply set temperature Tg,set2, cold storage inlet and outlet set temperature difference △TW,set1, cold release inlet and outlet set temperature difference △TW,set2, target cold storage capacity Qch,set and peak electricity price period load forecast value Qpeak; The electricity price tiered time periods include flat electricity price periods, peak electricity price periods, peak electricity price periods, and off-peak electricity price periods; S2: Obtain the current water flow rate L of the phase change cold storage box (8), the first monitoring temperature TW,in of the first temperature sensor T1, the second monitoring temperature TW,out of the second temperature sensor T2, the detection temperature TW of the third temperature sensor T3, and the fourth monitoring temperature Tchiller,out of the fourth temperature sensor T4. S3: If the current time is not within the cooling period, proceed to step S4; otherwise, proceed to step S7. S4: If the current time is during the off-peak electricity price period, proceed to step S5; otherwise, return to step S1. S5: When the current cold storage capacity Qch of the phase change cold storage box (8) is not less than the target cold storage capacity Qch,set or the difference between the second monitoring temperature TW,out and the first monitoring temperature TW,in is less than the set temperature difference △TW,set1 at the cold storage inlet and outlet, return to step S1; otherwise, execute step S6. S6: Execute the refrigeration unit's cold storage mode. When the fourth monitored temperature Tchiller,out equals the cold storage set water temperature Tch,set, return to step S1. S7: If the current time is during the peak electricity price period, proceed to step S8; if the current time is during the peak electricity price period, proceed to step S13; if the current time is during the flat electricity price period, proceed to step S9; if the current time is during the off-peak electricity price period, proceed to step S14. S8: Determine whether the phase change cold storage box (8) has stopped supplying cold on the same day. If yes, proceed to step S9; otherwise, proceed to step S10. Among them, the initial value of the day when the phase change cold storage box (8) stops supplying cold is no; S9: Execute the cooling unit's independent cooling mode. When the fourth monitored temperature Tchiller,out equals the second water supply set temperature Tg,set2, return to step S1. S10: Determine whether the combined cooling mode of the refrigeration unit and the phase change cold storage box (8) has been started on the same day. If yes, proceed to step S11; otherwise, proceed to step S12. The initial value for the day of the combined cooling mode of the refrigeration unit and the phase change cold storage box (8) is no; S11: Execute the combined cooling mode of the refrigeration unit and the phase change cold storage box (8). When the difference between the second monitoring temperature TW,out and the first monitoring temperature TW,in is less than the set temperature difference △TW,set2 at the cold release inlet and outlet, record and stop the cooling of the phase change cold storage box (8) for the day and proceed to step S9. Otherwise, return to step S1. S12: Execute the phase change cold storage box (8) in separate cooling mode. When the second monitored temperature TW,out is less than or equal to the first water supply set temperature Tg,set1, return to step S1; otherwise, proceed to step S11. S13: If the current cold storage capacity Qch is greater than the load prediction value Qpeak, proceed to step S8; otherwise, proceed to step S9. S14: When the current cold storage capacity Qch is not less than the target cold storage capacity Qch,set or the difference between the second monitoring temperature TW,out and the first monitoring temperature TW,in is less than the set temperature difference △TW,set1 at the cold storage inlet and outlet, proceed to step S9; otherwise, proceed to step S15. S15: Execute the simultaneous cooling and cold storage mode of the refrigeration unit. When the fourth monitored temperature Tchiller,out equals the cold storage set water temperature Tch,set, return to step S1.

2. The control method for the phase change cold storage air conditioning system in a subway station according to claim 1, characterized in that, The refrigeration unit's cold storage mode includes: Turn on the chiller unit (1), chilled water pump (2), cooling tower (3), cooling water pump (4), first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V6 and second electric bidirectional regulating valve VT2, and close the electric bidirectional switch valve V5 and the first electric regulating valve VT1. The independent cooling mode of the refrigeration unit includes: Turn on the chiller unit (1), chilled water pump (2), cooling tower (3), cooling water pump (4), first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4 and first electric regulating valve VT1, and close electric bidirectional switch valve V5, electric bidirectional switch valve V6 and second electric bidirectional regulating valve VT2. The combined cooling mode of the refrigeration unit and the phase change cold storage box (8) includes: Turn on the chiller unit (1), chilled water pump (2), cooling tower (3), cooling water pump (4), first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V5, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2, and close the electric bidirectional switch valve V6. The phase change cold storage box (8) has the following independent cooling modes: Turn on the chilled water pump (2), electric two-way switch valve V5, first electric regulating valve VT1 and second electric two-way regulating valve VT2, and turn off the chiller unit (1), cooling tower (3), cooling water pump (4), first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4 and electric two-way switch valve V6. The refrigeration unit simultaneously provides cooling and cold storage modes, including: Turn on the chiller unit (1), chilled water pump (2), cooling tower (3), cooling water pump (4), first electric switch valve V1, second electric switch valve V2, third electric switch valve V3, fourth electric switch valve V4, electric bidirectional switch valve V6, first electric regulating valve VT1 and second electric bidirectional regulating valve VT2, and close the electric bidirectional switch valve V5.

3. The control method for the phase change cold storage air conditioning system in a subway station according to claim 1 or 2, characterized in that, The phase change cold storage box (8) has multiple phase change cold storage modules (81) built in; the multiple phase change cold storage modules (81) are parallel to each other and spaced apart.

4. The control method for the phase change cold storage air conditioning system in a subway station according to claim 3, characterized in that, The outer shell of the phase change cold storage box (8) is made of metal or plastic; centrifugal glass wool is provided around the outside of the phase change cold storage box (8).

5. The control method for the phase change cold storage air conditioning system in a subway station according to claim 3, characterized in that, The phase change cold storage module (81) includes a phase change layer and a support layer. The phase change layer is embedded in the support layer. The phase change layer is made of inorganic hydrated salt, paraffin or organic-inorganic composite phase change material. The support layer is made of metal plate or plastic shell. The phase change temperature of the phase change layer is 8℃-10℃.

6. The control method for a phase change cold storage air conditioning system in a subway station according to claim 1 or 2, characterized in that, It also includes a differential pressure bypass device (7), through which the water collector (5) is connected to the water distributor (6).

7. The control method for a phase change cold storage air conditioning system in a subway station according to claim 1 or 2, characterized in that, It also includes a constant pressure water supply device (9), which is connected to the water collector (5).

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