Integrated evaporative cooling type and natural cooling type variable-frequency magnetic suspension centrifugal water chilling unit

Abstract

The utility model discloses an integrated evaporative cooling type and natural cooling type variable-frequency magnetic suspension centrifugal water chilling unit, which relates to the field of refrigeration and freezing equipment and comprises a compressor, an evaporator, an evaporative cooling type unit, an isolation plate exchanger, a freezing hydraulic power conveying module unit, a cooling water power conveying module unit, a pipeline and a control loop. According to the utility model, the evaporative condensation technology, the compressor magnetic suspension technology, the frequency conversion technology and the natural cooling technology are fused and applied, and the chilled water and cooling water conveying device is integrated, so that the reliability and the operation efficiency of the evaporative condenser and the natural cooling application are further improved, the annual efficient operation is realized, and the operation requirements of energy-saving equipment are better met.

Description

Technical Field

[0001] The utility model relates to the field of refrigeration and freezing equipment, and particularly relates to an integrated evaporative cooling type variable frequency magnetic levitation centrifugal chiller with natural cooling. Background Art

[0002] Evaporative condensation technology is a highly efficient power-saving and water-saving technology. By spraying and distributing cooling circulating water on the surface of the heat exchanger to form a continuous water film, heat exchange is carried out between the water and the refrigerant fluid in the heat exchanger in an evaporation heat absorption manner. The refrigerant is quickly cooled, and the heat is transferred to the air flow after the water vaporizes, and then is discharged outside the machine by the fan. The cooling efficiency can be increased by more than 45% compared with the air-cooled type. In recent years, with the energy efficiency upgrade of chiller equipment, using an evaporative cooling condenser has become an excellent option. However, the evaporative condenser also has problems such as easy corrosion and scaling of the heat exchange tubes, and a relatively high water drift rate, which need to be solved emphatically.

[0003] The compressor magnetic levitation + variable frequency technology is a highly efficient energy-saving technology. The core component is the magnetic levitation bearing of the compressor. By using the magnetic force to suspend the rotor in the air, there is no mechanical contact between the rotor and the stator, and it has many advantages such as oil-free, frictionless, low noise, and low power consumption, which can significantly improve the energy efficiency of the compressor under partial load operation.

[0004] Natural cooling technology uses the natural temperature difference between the cooling fluid and the outdoor air for heat exchange. Generally, a heat exchange temperature difference of more than 10°C is required, and it is often realized by using a copper-aluminum finned tube heat exchanger + fan method. The fluid in the heat exchange tube is fully heat-exchanged with the outdoor air, and the air is discharged by the fan after absorbing heat. This method only consumes the power of a small-power fan and does not require the compressor to do work, so the energy saving is significant. For traditional chillers, the supply and return water temperatures of the chilled water are 12 / 7°C. To use natural cooling technology, according to the requirements of the heat exchange temperature difference, the outdoor ambient temperature needs to be about -3°C or lower, which means the unit needs to operate in winter environment to achieve it; the supply and return water temperatures required by the equipment in the data center computer room are generally 21 / 15°C, and its water temperature is higher. When the outdoor ambient temperature is 5°C, it has the natural cooling temperature difference condition. This type of air-conditioning equipment needs to refrigerate all year round, and there is a larger temperature difference from the outdoor ambient temperature in winter. Using natural cooling technology is more beneficial. The lower the outdoor ambient temperature, the greater the utilization value of natural cooling technology, and it is more suitable for application in the cold northern regions. However, when operating air-conditioning equipment in winter, it is necessary to solve the problem of equipment anti-freezing. Usually, the antifreeze solution is added to the chilled water system for anti-freezing. While solving the anti-freezing problem, the antifreeze solution will also have adverse effects. One is to reduce the heat exchanger efficiency, and the other is to increase the resistance of the chilled water delivery pipeline, and a larger power chilled water pump needs to be configured. Obviously, this reduces the energy efficiency of the chilled water application system.

[0005] In long-term use and observation, it has been found that in recent years, the integrated design concept has become popular in central air-conditioning products. The application demand for integrated units that integrate the functions of chilled water transportation and cooling water transportation has been increasing day by day. The application scenario of multiple integrated units sharing a water system on-site has become more and more common. However, due to structural size and cost limitations in factory-designed products, the water system designs of many manufacturers' integrated products are unreasonable, functional components are simplified, and it is difficult to prevent dirt from entering the evaporator during the water system commissioning of the built-in chilled water pump unit in the user's water system. There are disadvantages such as low reliability and inconvenient maintenance. When multiple units share a water system, there is a phenomenon of chilled water bypass in the non-operating units, which is not conducive to water temperature operation control and will increase operating costs.

[0006] Therefore, the present utility model provides an integrated evaporative cooling type variable-frequency magnetic levitation centrifugal chiller with natural cooling. Content of the Utility Model

[0007] The purpose of the present utility model is to overcome the deficiencies existing in the prior art, and to provide an integrated evaporative cooling type variable-frequency magnetic levitation centrifugal chiller with natural cooling, which integrates and applies evaporative condensation technology, compressor magnetic levitation technology, variable-frequency technology and natural cooling technology, and at the same time integrates chilled water and cooling water transportation devices, and further improves the reliability and operating efficiency of evaporative condensers and natural cooling applications, realizes efficient operation throughout the year, and better meets the operating requirements of energy-saving equipment.

[0008] The purpose of the present utility model is achieved by the following technical solutions: This integrated evaporative cooling type variable-frequency magnetic levitation centrifugal chiller with natural cooling includes a compressor, an evaporator, an evaporative cooling unit, an isolation plate heat exchanger, a chilled water hydraulic transportation module unit, a cooling water hydraulic transportation module unit, and pipelines and control circuits;

[0009] The compressor uses a variable-frequency magnetic levitation centrifugal compressor. The exhaust port of the compressor is connected to the inlet of the evaporative condenser of the evaporative cooling unit. The outlet of the evaporative condenser is connected to the tube-side inlet of the evaporator. The tube-side outlet of the evaporator is connected to the suction port of the compressor to realize compression refrigeration;

[0010] The chilled water hydraulic transportation module unit is arranged on one side of the isolation plate heat exchanger. The chilled water hydraulic transportation module unit is communicated with the inlet and outlet of the user end, and the chilled water hydraulic transportation module unit is also connected to the water-side inlet and outlet of the evaporator. The cooling water hydraulic transportation module unit is arranged on the other side of the isolation plate heat exchanger. Heat exchange between chilled water and cooling water is carried out through the isolation plate heat exchanger. A finned tube heat exchanger is provided in the cooling water hydraulic transportation module unit, and a natural cooling fan is installed inside the finned tube heat exchanger to realize natural cooling. In the natural cooling mode, the insufficient part of the refrigerating capacity is put into operation of the compressor for refrigeration to realize combined refrigeration.

[0011] As a further technical solution, the exhaust port of the compressor is provided with a one-way valve connected to the evaporative condenser, and a branch is provided at the outlet of the one-way valve for connecting to the evaporator, and a hot gas bypass valve is provided on the branch to enable the compressor to adapt to partial load operation.

[0012] As a further technical solution, the compressor exhaust passes through a one-way valve and then flows to an evaporative condenser for efficient cooling by evaporative condensation. A stop valve, a drying filter and a first throttling device are sequentially arranged at the outlet of the evaporative condenser, and the first throttling device is connected to the evaporator.

[0013] As a further technical solution, an economizer is arranged between the drying filter and the first throttling device. After the high-temperature and high-pressure refrigerant gas is cooled into liquid in the evaporative condenser, it enters the economizer after passing through the drying filter; the economizer adopts a brazed plate heat exchanger, and the main channel fluid is the high-temperature refrigerant liquid formed by cooling the evaporative condenser. A second throttling device is arranged on the auxiliary channel of the economizer, so that the auxiliary channel fluid is the low-temperature and low-pressure two-phase refrigerant fluid formed by throttling by the second throttling device. After the two fluids undergo convection heat exchange, the main channel liquid becomes a supercooled liquid and enters the first throttling device for throttling, pressure reduction and temperature reduction. The low-temperature and low-pressure refrigerant two-phase fluid formed by throttling enters the evaporator for heat exchange; after the refrigerant two-phase fluid in the auxiliary channel of the economizer forms superheated gas through heat exchange, it returns to the economizer interface of the compressor through the solenoid valve.

[0014] As a further technical solution, the evaporative cooling unit is provided with a water collection tank, which is connected to a spray water distribution system through a pipeline, and a spray water pump and a third electronic descaling device are installed on the pipeline in sequence, and the third electronic descaling device is arranged at a position close to the spray water distribution side; an evaporative condenser is provided below the spray water distribution system, a water spraying filler is provided between the evaporative condenser and the water collection tank, and a water eliminator is provided on the side of the water spraying filler; an evaporative cooling fan is provided above the entire evaporative cooling unit.

[0015] As a further technical solution, the chilled hydraulic transmission module unit includes a chilled water pump, one end of which is connected to the first filter, the first water circuit valve, the expansion tank, the safety valve and the first pressure gauge in sequence, and is connected to the user-end water outlet, the other end of the chilled water pump is connected to the first soft connection, the first check valve, the first electronic descaling device and the second water circuit valve in sequence, and is connected to the chilled water side inlet of the isolation plate exchanger, the chilled water side outlet of the isolation plate exchanger is connected to the third water circuit valve and the fifth water circuit valve in sequence, and is connected to the water side inlet of the evaporator, the water side outlet of the evaporator is connected to the first water flow switch, the sixth water circuit valve and the automatic control valve in sequence, and is connected to the user-end water inlet.

[0016] As a further technical solution, a fourth waterway valve is bypass-connected between the second waterway valve and the third waterway valve, a seventh waterway valve is bypass-connected between the fifth waterway valve and the sixth waterway valve, and the second waterway valve and the first electronic descaling device are bypassed to the user-side water inlet through a pipeline. An eighth waterway valve and a first automatic air vent valve are arranged on the pipeline; a bypass pipeline is provided between the first filter and the first waterway valve, and a ninth waterway valve and an automatic water replenishing valve are connected in parallel on the bypass pipeline; a first drain valve is provided between the chilled water pump and the first filter.

[0017] As a further technical solution, the cooling water hydraulic conveying module unit includes a cooling water pump. The inlet of the cooling water side of the isolation plate heat exchanger is sequentially connected to an eleventh waterway valve, a second electronic descaling device, a second check valve, the cooling water pump, a second flexible joint, a fourteenth waterway valve, a second filter and a thirteenth waterway valve, and is connected to the expansion tank. The outlet of the cooling water side of the isolation plate heat exchanger is sequentially connected to a tenth waterway valve, a second pressure gauge and a second water flow switch, and is connected to the finned tube heat exchanger.

[0018] As a further technical solution, a pipeline bypasses between the expansion tank and the thirteenth waterway valve to the finned tube heat exchanger, and a twelfth waterway valve is arranged on the pipeline; a second automatic air vent valve is arranged on the pipeline between the second water flow switch and the finned tube heat exchanger; a second drain valve is arranged on the pipeline between the fourteenth waterway valve and the second filter.

[0019] As a further technical solution, another set of cooling water pumps is arranged in parallel between the second electronic descaling device and the second filter, with one in use and one in reserve; the other set of cooling water pumps is connected to the second electronic descaling device through another second check valve, and is connected to the second filter through another second flexible joint and the fourteenth waterway valve.

[0020] The beneficial effects of the utility model are as follows:

[0021] 1. The compressor adopts a variable-frequency magnetic levitation centrifugal compressor. Compared with the existing annual refrigeration type conventional chiller products, the annual operating efficiency of the unit is greatly improved, which can be increased by more than 40%;

[0022] 2. In the application scenarios where the chilled water outlet temperature is greater than 12°C, such as in the data center computer room application, the economizer design can be cancelled, effectively reducing the unit design cost;

[0023] 3. Compared with existing similar products, the reliability level of the unit has been significantly improved. The heat exchange tubes of the evaporative condenser are made of stainless steel SUS316L and continuously bent into shape, significantly reducing the risk of corrosion failure. The compressor frequency converter uses air cooling, which can adapt to the refrigeration operation environment throughout the year. It is simpler, more reliable and easier to maintain than the fluorine liquid cooling and water cooling modes. The natural cooling application mode adopts a separated plate heat exchanger design, with a coolant circulation for the built-in cooling water. The outdoor heat exchanger uses thermal insulation and electric heating wire auxiliary heating to prevent freezing, and the condenser water tank uses electric heating to prevent freezing, significantly improving the anti-freezing operation reliability of the outdoor unit. The refrigeration hydraulic transmission unit is designed with multiple bypass branches, effectively preventing the dirty blockage of the heat exchanger during water testing, facilitating maintenance and improving the operation safety redundancy.

[0024] 4. The integrated unit design integrates the hydraulic module unit of the refrigeration pump and the coolant transmission unit for the built-in cooling water. The highly integrated design saves the project cost and investment for users. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the pipeline connection structure of Embodiment 1 in the present utility model.

[0026] Figure 2 It is a schematic diagram of the pipeline connection structure of Embodiment 2 in the present utility model.

[0027] Figure 3 It is a schematic diagram of the structure of the evaporative cooling unit in the present utility model.

[0028] Figure 4 It is a front view structural schematic diagram of the unit in the present utility model.

[0029] Figure 5 It is a top view structural schematic diagram of the unit in the present utility model.

[0030] Figure 6 It is a side view structural schematic diagram of the unit in the present utility model.

[0031] Description of the reference numerals: compressor 1, evaporative condenser 2, evaporator 3, first throttling device 4, evaporative cooling unit 5, plate heat exchanger 6, finned tube heat exchanger 7, dryer filter 8, hot gas bypass valve 9, check valve 10, evaporative cooling fan 11, stop valve 12, economizer 13, second throttling device 14, solenoid valve 15, natural cooling fan 16, chilled water pump 101, first filter 102, first check valve 103, first electronic descaling device 104, first automatic air vent valve 105, first water flow switch 106, expansion tank 107, safety valve 108, automatic make-up water valve 109, first waterway valve 110, second waterway valve 111, third waterway valve 112, fourth waterway valve 113, fifth waterway valve 114, sixth waterway valve 115, seventh waterway valve 116, automatic control valve 117, eighth waterway valve 118, ninth waterway valve 119, first drain valve 120, first flexible joint 121, first pressure gauge 122, cooling water pump 201, second filter 202, second check valve 203, second electronic descaling device 204, second automatic air vent valve 205, second water flow switch 206, expansion water tank 207, fourteenth waterway valve 210, tenth waterway valve 211, eleventh waterway valve 212, twelfth waterway valve 213, thirteenth waterway valve 214, second drain valve 220, second flexible joint 221, second pressure gauge 222, sump 302, water eliminator 303, spray water distribution 304, splash packing 305, third electronic descaling device 306, spray water pump 307. Detailed implementation mode

[0032] The following will introduce the present utility model in detail with reference to the accompanying drawings:

[0033] Embodiment 1: As shown in the appendix Figure 1 、 3As shown in the figure, this integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller includes a compressor 1, an evaporative condenser 2, an evaporator 3, a first throttling device 4, an evaporative cooling unit 5, an isolation plate heat exchanger 6, a finned tube heat exchanger 7, a dryer filter 8, a hot gas bypass valve 9, a check valve 10, an evaporative cooling fan 11, a stop valve 12, an economizer 13, a second throttling device 14, a solenoid valve 15, a natural cooling fan 16, a chilled water pump 101, a first filter 102, a first check valve 103, a first electronic scale inhibitor 104, a first automatic air vent valve 105, a first water flow switch 106, an expansion tank 107, a safety valve 108, an automatic make-up water valve 109, a first waterway valve 110, a second waterway valve 111, a third waterway valve 112, a fourth waterway valve 113, a fifth waterway valve 114, a sixth waterway valve 115, a seventh waterway valve 116, an automatic control valve 117, an eighth waterway valve 118, a ninth waterway valve 119, a first drain valve 120, a first flexible joint 121, a first pressure gauge 122, a cooling water pump 201, a second filter 202, a second check valve 203, a second electronic scale inhibitor 204, a second automatic air vent valve 205, a second water flow switch 206, an expansion water tank 207, a fourteenth waterway valve 210, a tenth waterway valve 211, an eleventh waterway valve 212, a twelfth waterway valve 213, a thirteenth waterway valve 214, a second drain valve 220, a second flexible joint 221, a second pressure gauge 222, a sump 302, a water eliminator 303, a spray water distributor 304, a splash packing 305, a third electronic scale inhibitor 306 and a spray water pump 307.

[0034] Refer to the attached Figure 1 As shown in the figure, the compressor 1 adopts a variable frequency magnetic levitation centrifugal compressor. At the same time, the compressor 1 uses R134a refrigerant. The exhaust port of the compressor 1 is connected to the inlet of the evaporative condenser 2 of the evaporative cooling unit 5. The outlet of the evaporative condenser 2 is connected to the inlet of the tube side of the evaporator 3. The outlet of the tube side of the evaporator 3 is connected to the suction port of the compressor 1 to realize compression refrigeration.

[0035] A chilled water hydraulic transmission module unit is arranged on one side of the isolation plate heat exchanger 6. The chilled water hydraulic transmission module unit is communicated with the inlet and outlet of the user end, and the chilled water hydraulic transmission module unit is also connected to the inlet and outlet of the water side of the evaporator 3. A cooling water hydraulic transmission module unit is arranged on the other side of the isolation plate heat exchanger 6. Heat exchange between chilled water and cooling water is carried out through the isolation plate heat exchanger 6. A finned tube heat exchanger 7 is arranged in the cooling water hydraulic transmission module unit, and a natural cooling fan 16 is installed inside the finned tube heat exchanger 7 to realize natural cooling. In the natural cooling mode, the insufficient part of the refrigerating capacity is put into operation of the compressor 1 for refrigeration to realize combined refrigeration.

[0036] A check valve 10 is provided at the exhaust port of the compressor 1 and is connected to the evaporative condenser 2. A branch is provided at the outlet of the check valve 10 to connect to the evaporator 3, and a hot gas bypass valve 9 is provided on this branch to enable the compressor 1 to operate under part load. After the exhaust gas of the compressor 1 passes through the check valve 10, it leads to the evaporative condenser 2 for efficient cooling in an evaporative condensation manner. A stop valve 12, a dryer filter 8, and a first throttling device 4 are sequentially provided at the outlet of the evaporative condenser 2, and the first throttling device 4 is connected to the evaporator 3.

[0037] Furthermore, an economizer 13 can be provided between the dryer filter 8 and the first throttling device 4. After the high-temperature and high-pressure refrigerant gas is cooled into a liquid in the evaporative condenser 2, it enters the economizer 13 after passing through the dryer filter 8. The economizer 13 adopts a brazed plate heat exchanger. The main channel fluid is the high-temperature refrigerant liquid formed by the cooling of the evaporative condenser 2. A second throttling device 14 is provided on the auxiliary channel of the economizer 13, so that the auxiliary channel fluid is the low-temperature and low-pressure two-phase refrigerant fluid formed by the throttling of the second throttling device 14. After the two fluids perform convective heat exchange, the liquid in the main channel becomes a subcooled liquid and enters the first throttling device 4 for throttling, pressure reduction, and temperature reduction. The low-temperature and low-pressure refrigerant two-phase fluid formed by throttling enters the evaporator 3 for heat exchange. After the refrigerant two-phase fluid in the auxiliary channel of the economizer 13 forms a superheated gas through heat exchange, it returns to the economizer interface of the compressor 1 through the solenoid valve 15.

[0038] As Figure 3 shown, the evaporative cooling unit 5 is provided with a sump 302. The sump 302 is connected with a spray water distributor 304 through a pipeline, and a spray water pump 307 and a third electronic descaling instrument 306 are sequentially installed on the pipeline. The third electronic descaling instrument 306 is arranged at a position close to the spray water distributor 304. An evaporative condenser 2 is provided below the spray water distributor 304. A water filling filler 305 is provided between the evaporative condenser 2 and the sump 302, and a water eliminator 303 is provided on the side of the water filling filler 305. An evaporative cooling fan 11 is provided above the entire evaporative cooling unit 5. Preferably, the evaporative condenser 2 adopts a serpentine tube bundle type heat exchange tube, which is continuously bent and formed without butt welds. The material is high-grade stainless steel SUS316L, with excellent corrosion resistance. The design of the same direction of air and water heat exchange, large-flow spraying, and large-volume water tank improves the anti-scaling performance. The design of a large sedimentation and separation space effectively reduces water drift. The evaporative cooling unit includes related accessories such as a circulating water pump, a water distributor, a sump, water replenishment, and drainage. An auxiliary electric heating is designed in the sump to adapt to anti-freezing operation in winter.

[0039] Further, the chilled water hydraulic transportation module unit includes a chilled water pump 101. One end of the chilled water pump 101 is sequentially connected to a first filter 102, a first waterway valve 110, an expansion tank 107, a safety valve 108, and a first pressure gauge 122, and is connected to the user-side water outlet. The other end of the chilled water pump 101 is sequentially connected to a first flexible joint 121, a first check valve 103, a first electronic scale inhibitor 104, and a second waterway valve 111, and is connected to the chilled water side inlet of the plate heat exchanger 6. The chilled water side outlet of the plate heat exchanger 6 is sequentially connected to a third waterway valve 112 and a fifth waterway valve 114, and is connected to the water side inlet of the evaporator 3. The water side outlet of the evaporator 3 is sequentially connected to a first water flow switch 106, a sixth waterway valve 115, and an automatic control valve 117, and is connected to the user-side water inlet. Preferably, a fourth waterway valve 113 is bypass-connected between the second waterway valve 111 and the third waterway valve 112, a seventh waterway valve 116 is bypass-connected between the fifth waterway valve 114 and the sixth waterway valve 115, and the pipeline between the second waterway valve 111 and the first electronic scale inhibitor 104 is bypassed to the user-side water inlet, and an eighth waterway valve 118 and a first automatic air vent valve 105 are arranged on the pipeline; a bypass pipeline is provided between the first filter 102 and the first waterway valve 110, and a ninth waterway valve 119 and an automatic make-up water valve 109 are connected in parallel on the bypass pipeline; a first drain valve 120 is provided between the chilled water pump 101 and the first filter 102.

[0040] Further, the cooling water hydraulic transportation module unit includes a cooling water pump 201. The cooling water side inlet of the plate heat exchanger 6 is sequentially connected to an eleventh waterway valve 212, a second electronic scale inhibitor 204, a second check valve 203, the cooling water pump 201, a second flexible joint 221, a fourteenth waterway valve 210, a second filter 202, and a thirteenth waterway valve 214, and is connected to an expansion water tank 207. The cooling water side outlet of the plate heat exchanger 6 is sequentially connected to a tenth waterway valve 211, a second pressure gauge 222, and a second water flow switch 206, and is connected to the finned tube heat exchanger 7.

[0041] Preferably, a pipeline between the expansion water tank 207 and the thirteenth waterway valve 214 is bypassed to the finned tube heat exchanger 7, and a twelfth waterway valve 213 is arranged on the pipeline; a second automatic air vent valve 205 is arranged on the pipeline between the second water flow switch 206 and the finned tube heat exchanger 7; a second drain valve 220 is arranged on the pipeline between the fourteenth waterway valve 210 and the second filter 202.

[0042] Example 2: As Figure 2 、 Figure 4 、 Figure 5 and Figure 6As shown, it is an integrated R134a evaporative cooling variable-frequency magnetic levitation centrifugal chiller, which is applied to a data center project. The refrigerating capacity of the chiller is 580kW, the designed return water temperature of the chilled water is 24°C, the outlet water temperature is 18°C, and the lowest ambient temperature in winter is -25°C. In this embodiment, the chilled water outlet temperature is much higher than the conventional 7°C. The designed evaporation temperature of the compressor 1 is 15°C, the evaporation cooling condensation temperature is 36°C, and the high-low pressure ratio of the refrigeration cycle system is 1.87. The design of the refrigeration system process is simplified, that is, the economizer loop design is cancelled relative to Embodiment 1. The frequency converter configured for the magnetic levitation variable-frequency centrifugal compressor is air-cooled, with a simple design and very convenient maintenance. To improve the operating energy efficiency of the chilled water system, the chilled water pump 101 is driven by frequency conversion. To improve the reliability of the cooling water system, at the same time, the cooling water pumps are designed in a one-use-one-backup mode, and the two cooling water pumps 201 are backup water pumps for each other. That is, another group of cooling water pumps 201 is arranged in parallel between the second electronic scale inhibitor 204 and the second filter 202 to form a one-use-one-backup; another group of cooling water pumps 201 is connected to the second electronic scale inhibitor 204 through another second check valve 203, and is connected to the second filter 202 through another second flexible joint 221 and the fourteenth waterway valve 210.

[0043] See Figure 6 As shown, this unit adopts a functional section unit design layout, which is divided into a total of five functional module units: a main unit, an evaporative cooling unit, a natural cooling unit, a chilled water hydraulic transportation module unit, and a cooling water hydraulic transportation module unit. The main unit and the evaporative cooling unit are the most important structural unit bodies, designed in a parallel manner to ensure that their functions are exerted and their construction and maintenance have a high degree of independence. The natural cooling unit, the chilled water hydraulic transportation module unit, and the cooling water hydraulic transportation module unit are integrated and embedded in the main unit to form an integrated structure style. The external dimensions of the unit are 8300L*2500W*2850H. Compared with the current integrated central air-conditioning units with this function, the structure is already very compact, suitable for transportation, and convenient for operation and maintenance.

[0044] The working process of the present utility model:

[0045] The unit is internally provided with a chilled water hydraulic transportation module unit and configured with a cooling water hydraulic transportation module unit. On the traditional chiller, high-efficiency design technologies are used for innovation and upgrading. The evaporative condenser is used to replace the water-cooled condenser, the variable-frequency magnetic levitation centrifugal compressor is used to replace the ordinary centrifugal compressor, the natural cooling enhancement function is configured, the chilled water hydraulic transportation module unit is carried, the isolation plate heat exchanger 6 is used and the cooling water hydraulic transportation module unit is internally provided to improve the operation efficiency and reliability and convenience, and it becomes a highly integrated integrated high-efficiency chiller.

[0046] The unit consists of a compression refrigeration cycle system and a natural cooling system, and can achieve three operating modes: compression refrigeration, natural cooling, and combined refrigeration. The three modes can be automatically switched. The unit controller determines and selects the current optimal operating mode based on parameters such as the outdoor ambient temperature and the operating water temperature. For example, if the local outdoor ambient temperature is as low as -10°C and the chilled water outlet temperature is 7°C, it is preferably to use compression refrigeration when the outdoor ambient temperature ≥ 10°C, to give priority to natural cooling when the outdoor ambient temperature < 0°C, and to use combined refrigeration operation in other outdoor ambient temperature regions.

[0047] The refrigeration cycle system of the unit consists of four major components: a high-efficiency magnetic levitation variable-frequency centrifugal compressor 1, a high-efficiency evaporative condenser 2, a high-efficiency flooded evaporator 3, and a first throttling device 4, and is equipped with an economizer 13 for efficiency enhancement. When the unit is operating in the compression refrigeration mode, the exhaust gas of the compressor 1 passes through the check valve 10 and then leads to the evaporative condenser 2 for efficient cooling in an evaporation and condensation manner. After the high-temperature and high-pressure refrigerant gas is cooled into a liquid, it enters the economizer 13 after passing through the dryer filter 8. The economizer 13 is a brazed plate heat exchanger. The main channel fluid is the high-temperature refrigerant liquid formed by the cooling of the condenser, and the auxiliary channel is the low-temperature and low-pressure two-phase refrigerant fluid throttled by the second throttling device 14. After the two fluids perform convective heat exchange, the liquid in the main channel becomes a subcooled liquid and enters the first throttling device 4 for throttling, pressure reduction, and temperature reduction. The low-temperature and low-pressure refrigerant two-phase fluid formed by throttling enters the evaporator 3 for heat exchange. After the refrigerant absorbs the heat of the chilled water and becomes a superheated gas, it is finally sucked into the compressor 1, compressed and worked, and then discharged, completing a refrigeration cycle process. After the refrigerant two-phase fluid in the auxiliary channel of the economizer exchanges heat and becomes a superheated gas, it returns to the economizer interface of the compressor 1 through the solenoid valve 15. The magnetic levitation variable-frequency centrifugal compressor 1 is equipped with an IGV regulating valve and a hot gas bypass valve 9 to adapt to partial load operation and prevent the compressor 1 from surging.

[0048] The natural cooling system of the unit mainly consists of an isolation plate heat exchanger 6, a finned tube heat exchanger 7, natural cooling fans 16, and a cooling water hydraulic conveying module unit. The isolation plate heat exchanger 6 is designed to conduct heat exchange between the chilled water and the cooling water, enabling the chilled water to be cooled without the work of the compressor 1. The heat of the chilled water is transferred to the cooling water and is transported to the finned tube heat exchanger 7 by the cooling water pump 201 of the cooling water hydraulic conveying module unit. The cooling water is cooled by using the natural temperature difference formed by the cooling water and the outdoor ambient temperature. The heat of the cooling water is transferred to the air and discharged outside the unit by the natural cooling fans 16. The cooled cooling water then flows back to the isolation plate heat exchanger 6 to complete a closed-loop heat exchange process of the cooling water. In the natural cooling mode, the chilled water realizes the natural cooling function without the work of the compressor 1, and the operating energy efficiency is greatly improved.

[0049] The combined refrigeration operation mode is the integrated operation of the above two modes. The natural cooling mode is preferentially put into operation, and when the cooling capacity is insufficient, compressor 1 is put into operation for refrigeration. Since compressor 1 operates at partial capacity, the efficiency of its refrigeration system can also be significantly improved compared with the compression refrigeration mode. Therefore, the combined refrigeration mode is also a more energy-saving operation mode.

[0050] The cooling water hydraulic conveying module unit is equipped with necessary hydraulic components such as cooling water pump 201, second filter 202, and second check valve 203, and an expansion tank 207 is designed to stabilize the operation of the cooling water system pump. To prevent freezing in winter outdoors, the cooling water system uses antifreeze as the coolant, which is stored in the expansion tank 207. The unit heat exchanger and water pipeline adopt heat preservation + electric heating wire auxiliary heating for antifreeze. The chilled water system can use conventional clean water. The clean water system has no risk of corrosion and no impact on the performance of the heat exchanger. The chilled water pump can be selected according to the conventional working conditions without increasing the design of the head power, thus reducing the design cost of the chilled water system and the operation cost of the water system and improving the reliability.

[0051] The unit integrates a chilled water hydraulic conveying module unit, which has functions of automatic water replenishment, constant pressure, automatic air exhaust, automatic pressure relief, water treatment and drainage, and bypass. Waterway valves are designed at the water inlet and outlet of the water side of the isolation plate heat exchanger 6 and the evaporator 3, which are composed of the first waterway valve 110, the second waterway valve 111, the third waterway valve 112, the fourth waterway valve 113, the fifth waterway valve 114, the sixth waterway valve 115, the seventh waterway valve 116, and the eighth waterway valve 118, forming a bypass branch. This bypass branch can be opened or closed to completely cut off the water flow into the heat exchanger path or reduce the circulating water flow into the heat exchanger, so as to avoid dirty water entering the heat exchanger to protect the evaporator 3 during the commissioning and cleaning of the unit engineering water system, or when the water flow of the evaporator 3 is too large, the water flow of the evaporator 3 can be reduced to lower the water flow velocity in the heat exchange tubes to protect the evaporator 3. The chilled water hydraulic conveying module unit is easy to maintain. Only the relevant valves inside the unit need to be operated, which has nothing to do with the operation of the valves at the user end outside the unit. Close the first waterway valve 110, the second waterway valve 111, and the fourth waterway valve 113, and open the first drain valve 120 to disassemble and clean the first filter 102 and maintain the first chilled water pump 101. Close the fifth waterway valve 114 and the sixth waterway valve 115, and open the seventh waterway valve 116 to independently maintain the evaporator 3 during natural cooling operation. When compressor 1 is in refrigeration operation, close the inlet and outlet valves of both ends of the isolation plate heat exchanger 6, namely the second waterway valve 111, the third waterway valve 112, the tenth waterway valve 211, and the eleventh waterway valve 212, to independently maintain the isolation plate heat exchanger 6.

[0052] A bypass branch function is designed at the water side inlet and outlet of the heat exchanger (evaporator and isolation plate exchange) in the chilled water circulation system, which can realize the following application scenarios. Scenario 1: When the user's water system is tested and cleaned for the first time, the second water valve and the fourth water valve can be closed to isolate the evaporator and the isolation plate exchange from the water channel, and the eighth water valve of the bypass branch valve can be opened. This can isolate the water channel of the heat exchanger inside the unit, prevent debris from entering the heat exchanger, avoid blockage or erosion damage to the heat exchange tubes and plates, and significantly improve the safety and reliability of the heat exchanger. Scenario 2: The circulating water flow of the unit is too large, such as exceeding 1.5 times the rated water flow. On the other hand, it is easy to damage the evaporator. You can open the bypass branch valve and the seventh water valve for bypass flow to protect the evaporator. Scenario 3: When the isolation plate fails or needs maintenance, close the second and third water valves and open the fourth water valve to isolate the isolation plate from the running water system and improve operational reliability. Scenario 4: In the natural cooling operation mode in winter, if the evaporator needs maintenance or water drainage to prevent freezing, you can close the fifth and sixth water valves and open the seventh water valve to isolate the evaporator from the running water system, which helps to improve operational reliability.

[0053] In addition, in applications with high chilled water outlet, the economizer can be eliminated to reduce costs. When the compressor is cooling, if the chilled water outlet temperature is high, such as the supply and return water temperature is 15-21°C, and the system circulates in a high-efficiency evaporative cooling system, when the compressor is operating at nominal conditions, the evaporation temperature is generally 13°C and the condensation temperature is 37°C. For R134a refrigerant, the ratio of high pressure to low pressure of the compressor is 2.05. If the economizer is used to increase efficiency, the benefits are very small. Therefore, the economizer design can be eliminated. The economizer, the second throttling device, and the solenoid valve can be deleted from the system flow chart, thereby reducing the system design cost.

[0054] It is understandable that for those skilled in the art, any equivalent replacement or change of the technical solution and the concept of the utility model should fall within the scope of protection of the claims attached to the utility model.

Claims

1. An integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller, characterized in that: It includes a compressor (1), an evaporator (3), an evaporative cooling unit (5), a plate heat exchanger (6), a chilled water hydraulic conveying module unit, a cooling water hydraulic conveying module unit, and pipelines and a control circuit; The compressor (1) is a variable frequency magnetic levitation centrifugal compressor. The exhaust port of the compressor (1) is connected to the inlet of the evaporative condenser (2) of the evaporative cooling unit (5), the outlet of the evaporative condenser (2) is connected to the tube side inlet of the evaporator (3), and the tube side outlet of the evaporator (3) is connected to the suction port of the compressor (1) to achieve compression refrigeration; The chilled water hydraulic conveying module unit is arranged on one side of the plate heat exchanger (6). The chilled water hydraulic conveying module unit is communicated with the inlet and outlet water ports of the user end, and the chilled water hydraulic conveying module unit is also connected to the water side inlet and outlet of the evaporator (3). The cooling water hydraulic conveying module unit is arranged on the other side of the plate heat exchanger (6). Heat exchange between chilled water and cooling water is carried out through the plate heat exchanger (6). A finned tube heat exchanger (7) is arranged in the cooling water hydraulic conveying module unit, and a natural cooling fan (16) is installed inside the finned tube heat exchanger (7) to achieve natural cooling; in the natural cooling mode, when the cooling capacity is insufficient, the compressor (1) is put into operation for refrigeration to achieve combined refrigeration.

2. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 1, characterized in that: A check valve (10) is arranged at the exhaust port of the compressor (1) and is connected to the evaporative condenser (2). A branch is arranged at the outlet of the check valve (10) for connecting to the evaporator (3), and a hot gas bypass valve (9) is arranged on this branch to enable the compressor (1) to adapt to partial load operation.

3. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 2, characterized in that: After the exhaust of the compressor (1) passes through the check valve (10), it leads to the evaporative condenser (2) for efficient cooling in an evaporative condensation manner. A stop valve (12), a dryer filter (8), and a first throttling device (4) are sequentially arranged at the outlet of the evaporative condenser (2). The first throttling device (4) is connected to the evaporator (3).

4. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 3, characterized in that: An economizer (13) is arranged between the dryer filter (8) and the first throttling device (4). After the high-temperature and high-pressure refrigerant gas is cooled into a liquid in the evaporative condenser (2), it enters the economizer (13) after passing through the dryer filter (8); the economizer (13) adopts a brazed plate heat exchanger. The main channel fluid is the high-temperature refrigerant liquid formed by cooling in the evaporative condenser (2). A second throttling device (14) is arranged on the auxiliary channel of the economizer (13), so that the auxiliary channel fluid is the low-temperature and low-pressure two-phase refrigerant fluid formed by throttling of the second throttling device (14). After the two fluids carry out convective heat exchange, the liquid in the main channel becomes a subcooled liquid and enters the first throttling device (4) for throttling to reduce pressure and temperature. The low-temperature and low-pressure refrigerant two-phase fluid formed by throttling enters the evaporator (3) for heat exchange; after the refrigerant two-phase fluid in the auxiliary channel of the economizer (13) forms a superheated gas through heat exchange, it returns to the economizer interface of the compressor (1) through the solenoid valve (15).

5. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 1, characterized in that: The evaporative cooling unit (5) is provided with a water collecting tank (302), the water collecting tank (302) is connected to a spray water distribution system (304) via a pipeline, and a spray water pump (307) and a third electronic descaling device (306) are sequentially installed on the pipeline; an evaporative condenser (2) is provided below the spray water distribution system (304), a water spray filler (305) is provided between the evaporative condenser (2) and the water collecting tank (302), and a water remover (303) is provided on the side of the water spray filler (305); an evaporative cooling fan (11) is provided above the entire evaporative cooling unit (5).

6. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 1, characterized in that: The chilled water power delivery module unit comprises a chilled water pump (101), one end of the chilled water pump (101) is sequentially connected to a first filter (102), a first water circuit valve (110), an expansion tank (107), a safety valve (108) and a first pressure gauge (122), and is connected to a user-end water outlet; the other end of the chilled water pump (101) is sequentially connected to a first soft connection (121), a first check valve (103), a first electronic descaling device (104) and a second water circuit valve (111), and is connected to a chilled water side inlet of an isolation plate exchanger (6); the chilled water side outlet of the isolation plate exchanger (6) is sequentially connected to a third water circuit valve (112) and a fifth water circuit valve (114), and is connected to a water side inlet of an evaporator (3); the water side outlet of the evaporator (3) is sequentially connected to a first water flow switch (106), a sixth water circuit valve (115) and an automatic control valve (117), and is connected to a user-end water inlet.

7. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 6, wherein: A fourth water circuit valve (113) is bypass-connected between the second water circuit valve (111) and the third water circuit valve (112); a seventh water circuit valve (116) is bypass-connected between the fifth water circuit valve (114) and the sixth water circuit valve (115); a pipeline is bypassed between the second water circuit valve (111) and the first electronic descaling device (104) to the user-end water inlet, and an eighth water circuit valve (118) and a first automatic exhaust valve (105) are arranged on the pipeline; a bypass pipeline is provided between the first filter (102) and the first water circuit valve (110), and a ninth water circuit valve (119) and an automatic water supply valve (109) are connected in parallel on the bypass pipeline; and a first drain valve (120) is provided between the chilled water pump (101) and the first filter (102).

8. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 1, wherein: The cooling water power delivery module unit comprises a cooling water pump (201); the cooling water side inlet of the isolation plate exchanger (6) is sequentially connected to an eleventh water circuit valve (212), a second electronic descaling device (204), a second check valve (203), a cooling water pump (201), a second flexible connection (221), a fourteenth water circuit valve (210), a second filter (202) and a thirteenth water circuit valve (214), and is also connected to an expansion water tank (207); the cooling water side outlet of the isolation plate exchanger (6) is sequentially connected to a tenth water circuit valve (211), a second pressure gauge (222) and a second water flow switch (206), and is also connected to a fin tube heat exchanger (7).

9. The integrated evaporative cooling and natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 8, characterized in that: A pipeline bypasses between the expansion tank (207) and the thirteenth waterway valve (214) to the finned tube heat exchanger (7), and a twelfth waterway valve (213) is provided on the pipeline; a second automatic air vent valve (205) is provided on the pipeline between the second water flow switch (206) and the finned tube heat exchanger (7); a second drain valve (220) is provided on the pipeline between the fourteenth waterway valve (210) and the second filter (202).

10. The integrated evaporative cooling with natural cooling type variable frequency magnetic levitation centrifugal chiller according to claim 8, wherein: Another set of cooling water pumps (201) is arranged in parallel between the second electronic descaling instrument (204) and the second filter (202) to form one standby and one in use; the other set of cooling water pumps (201) is connected to the second electronic descaling instrument (204) through another second check valve (203), and is connected to the second filter (202) through another second flexible joint (221) and the fourteenth waterway valve (210).

Images