Double-cold-source integrated screw water chilling unit with high refrigeration water temperature

Abstract

The utility model discloses a double-cold-source integrated screw water chilling unit with high refrigeration water temperature, which relates to the technical field of refrigeration, and comprises a screw water chilling main machine, a cooling tower, an intermediate heat exchanger and a plurality of pipelines, a water inlet A of the evaporator is connected to a first outlet of the intermediate heat exchanger through a freezing water inlet pipeline, and a water outlet A of the evaporator is connected to a first inlet of the intermediate heat exchanger through a freezing water outlet pipeline; a water inlet B of the condenser is connected to a bottom outlet of the cooling tower through a cooling water inlet pipeline, and a water outlet B of the condenser is connected to a top inlet of the cooling tower through a cooling water outlet pipeline; and a second outlet and a second inlet of the intermediate heat exchanger are respectively connected to a user terminal for heat exchange. According to the utility model, the requirement of users for stable high-water-temperature water outlet all year round is met, frequent start and stop of the compressor during low load in transition seasons, winter and the like can be effectively avoided, the system energy consumption is reduced, and the operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of refrigeration technology, in particular to a high refrigeration water temperature dual-cold source integrated screw chiller unit. Background Art

[0002] Some current refrigeration projects, such as those for cooling process equipment, require stable, high circulating water temperatures year-round. Existing integrated screw chillers achieve cooling by directly exchanging heat with the user's end user through the chilled water circulating in and out of their evaporator. However, due to the screw compressor's differential oil supply, direct high-water temperature cooling at a low cost is difficult. Therefore, designing an integrated screw chiller that can meet the user's demand for stable, high-temperature heat exchange circulating water year-round while also ensuring low-cost operation is a pressing challenge. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a dual-cold source integrated screw chiller with high refrigeration water temperature, which can meet the user's demand for stable high water temperature output throughout the year while effectively avoiding the frequent start and stop of the compressor during low load periods such as transition seasons and winter, reducing system energy consumption and lowering operating costs.

[0004] The purpose of the utility model is achieved through the following technical solutions: this high refrigeration water temperature dual-cold source integrated screw chiller unit includes a screw chiller main unit, a cooling tower, an intermediate heat exchanger and several pipelines. The screw chiller main unit includes an evaporator and a condenser, and the two are connected by a compressor to realize refrigerant circulation. The water inlet A of the evaporator is connected to the first outlet of the intermediate heat exchanger through a chilled water inlet pipeline, and the water outlet A of the evaporator is connected to the first inlet of the intermediate heat exchanger through a chilled water outlet pipeline; the water inlet B of the condenser is connected to the bottom outlet of the cooling tower through a cooling water inlet pipeline, and the water outlet B of the condenser is connected to the top inlet of the cooling tower through a cooling water outlet pipeline; the second outlet and the second inlet of the intermediate heat exchanger are respectively connected to the user end for heat exchange.

[0005] As a further technical solution, the second outlet is connected to the user end through the user side water outlet pipe, and the second inlet is connected to the user end through the user side water inlet pipe, so that the chilled water inlet pipe and the chilled water outlet pipe only circulate water inside the unit and do not directly participate in the heat exchange at the user end. A user side water pump is set on the user side water inlet pipe.

[0006] As a further technical solution, the water outlet A is connected to the chilled water outlet pipeline through an electric butterfly valve B, and a buffer water tank is provided on the chilled water outlet pipeline near the first inlet; the water inlet A is connected to the chilled water inlet pipeline through an electric butterfly valve A, and a chilled water pump is provided on the chilled water inlet pipeline near the electric butterfly valve A; the water outlet B is connected to the cooling water outlet pipeline through a manual water outlet butterfly valve, and the water inlet B is connected to the cooling water inlet pipeline through a manual water inlet butterfly valve, and a cooling water pump is provided on the cooling water inlet pipeline near the cooling tower.

[0007] As a further technical solution, a proportional three-way valve is arranged between the water inlet manual butterfly valve and the cooling water pump, which is used to connect one end of the three-way valve bypass water channel, and the other end of the three-way valve bypass water channel is connected between the electric butterfly valve B and the buffer water tank, so that the chilled water outlet pipeline is bypassed to the cooling water inlet pipeline; a butterfly valve bypass water channel is arranged between the chilled water pump and the first outlet, and the other end of the butterfly valve bypass water channel is connected between the water outlet manual butterfly valve and the cooling tower, so that the chilled water inlet pipeline is bypassed to the cooling water outlet pipeline, and an electric butterfly valve C is arranged on the butterfly valve bypass water channel; the electric butterfly valve A, electric butterfly valve B, electric butterfly valve C and the proportional three-way valve are all automatically switched according to the ambient temperature to realize fully automatic switching of the circulating water channel.

[0008] As a further technical solution, when the ambient temperature is higher than the set value T1, the unit operates under high ambient temperature conditions. At this time, the compressor is running, the chilled water pump, cooling water pump, electric butterfly valve B and electric butterfly valve A are all open, the proportional three-way valve and electric butterfly valve C are closed, and the user side water pump remains on. At this time, the unit uses the screw chiller host for refrigeration.

[0009] As a further technical solution, when the ambient temperature is lower than the set value T1, the unit operates under low ambient temperature conditions. At this time, the compressor stops running, the chilled water pump, electric butterfly valve B and electric butterfly valve A are all closed, the cooling water pump, proportional three-way valve and electric butterfly valve C are all opened, and the user side water pump remains on. At this time, the unit directly uses the cooling tower for natural cooling.

[0010] As a further technical solution, when the proportional three-way valve is opened, the valve opening is automatically controlled according to the water temperature at the first inlet of the intermediate heat exchanger, thereby controlling the amount of water flowing into the first inlet.

[0011] As a further technical solution, the cooling tower is provided with a cooling fan and filler. The cooling fan automatically starts and stops according to the ambient temperature. When the ambient temperature is higher than the set value T2, the cooling fan starts. When the ambient temperature is lower than the set value T2, the cooling fan stops.

[0012] As a further technical solution, the set value T1 is 20°C, and the set value T2 is 10°C.

[0013] As a further technical solution, the intermediate heat exchanger adopts a plate heat exchanger or a shell and tube heat exchanger.

[0014] The beneficial effects of the utility model are:

[0015] 1. A separate user-side water circulation system is designed. Chilled water only circulates within the unit and does not directly participate in heat exchange at the user end. An intermediate heat exchanger is also designed to achieve heat exchange between the chilled circulating water and the user-side circulating water. This utilizes indirect heat exchange to meet the user's demand for high outlet water temperature.

[0016] 2. A buffer water tank is designed on the chilled water outlet pipe inside the unit. Since the chilled water of the unit only completes the water circulation inside the unit and the pipe space is limited, adding a buffer water tank can avoid frequent start and stop of the compressor and water temperature fluctuation caused by insufficient chilled water circulation;

[0017] 3. The proportional three-way valve and electric butterfly valve are used to realize automatic switching of water pipes under different ambient temperatures, which can effectively avoid the frequent start and stop of the compressor during refrigeration throughout the year, greatly reduce the energy consumption of the unit, reduce operating costs, and achieve fully automatic control, high efficiency and convenience;

[0018] 4. When only the cooling tower is used for cooling, the unit can automatically control the opening of the proportional three-way valve according to the inlet water temperature on the chilled water side of the intermediate heat exchanger, and control the amount of chilled water flowing into the intermediate heat exchanger, thereby meeting the water temperature requirement that matches the user side load;

[0019] 5. The cooling fan of the high-efficiency and energy-saving cooling tower can be automatically started and stopped according to the ambient temperature. Under low ambient temperature conditions, the cooling water can meet the heat dissipation requirements only by relying on the cooling tower filler. At this time, under the operating conditions, the cooling fan can automatically stop running, which can further reduce the energy consumption of the unit and reduce operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the present utility model.

[0021] Figure 2 This is a schematic diagram of the circulation process of the utility model under high ambient temperature conditions.

[0022] Figure 3 This is a schematic diagram of the circulation process of the utility model under low ambient temperature conditions.

[0023] Explanation of the accompanying symbols: evaporator 1, condenser 2, cooling tower 3, intermediate heat exchanger 4, user terminal 5, electric butterfly valve A6, chilled water pump 7, electric butterfly valve B8, buffer water tank 9, water inlet manual butterfly valve 10, cooling water pump 11, water outlet manual butterfly valve 12, proportional three-way valve 13, electric butterfly valve C14, user-side water pump 15, compressor 16, cooling fan 17, packing 18, screw chiller 19, chilled water inlet pipeline A, chilled water outlet pipeline B, cooling water inlet pipeline C, cooling water outlet pipeline D, three-way valve bypass water channel E, butterfly valve bypass water channel F, user-side water inlet pipeline G, user-side water outlet pipeline H, water outlet AⅠ, water inlet AⅡ, water outlet BⅢ, water inlet BⅣ, first inlet V, first outlet VI, second outlet VII, second inlet VIII. DETAILED DESCRIPTION

[0024] The following is a detailed introduction to the present invention with reference to the accompanying drawings:

[0025] Example: As shown in the attached Figures 1 to 3 As shown, this high refrigeration water temperature dual-cold source integrated screw chiller includes an evaporator 1, a condenser 2, a cooling tower 3, an intermediate heat exchanger 4, a user terminal 5, an electric butterfly valve A6, a chilled water pump 7, an electric butterfly valve B8, a buffer water tank 9, an inlet manual butterfly valve 10, a cooling water pump 11, an outlet manual butterfly valve 12, a proportional three-way valve 13, an electric butterfly valve C14, a user-side water pump 15, a compressor 16, a cooling fan 17, a packing 18, a screw chiller 19, a chilled water inlet pipeline A, a chilled water outlet pipeline B, a cooling water inlet pipeline C, a cooling water outlet pipeline D, a three-way valve bypass water path E, a butterfly valve bypass water path F, a user-side water inlet pipeline G, a user-side water outlet pipeline H, a water outlet AⅠ, a water inlet AⅡ, a water outlet BⅢ, a water inlet BⅣ, a first inlet V, a first outlet VI, a second outlet VII, and a second inlet VIII.

[0026] Reference Attachment Figure 1 The screw chiller 19 includes an evaporator 1 and a condenser 2, which are connected via a compressor 16 to achieve refrigerant circulation (the exhaust port of the compressor 16 is connected to the refrigerant inlet of the condenser 2, while the suction port of the compressor 16 is connected to the refrigerant outlet of the evaporator 1). The water inlet AⅡ of the evaporator 1 is connected to the first outlet VI of the intermediate heat exchanger 4 via a chilled water inlet pipe A, and the water outlet AⅠ of the evaporator 1 is connected to the first inlet V of the intermediate heat exchanger 4 via a chilled water outlet pipe B. The water inlet BⅣ of the condenser 2 is connected to the bottom outlet of the cooling tower 3 via a cooling water inlet pipe C, and the water outlet BⅢ of the condenser 2 is connected to the top inlet of the cooling tower 3 via a cooling water outlet pipe D.

[0027] The intermediate heat exchanger 4 is a plate heat exchanger or a shell-and-tube heat exchanger with four interfaces (first inlet V, first outlet VI, second outlet VII, and second inlet VIII). The second outlet VII is connected to the user terminal 5 via the user-side water outlet pipe H, and the second inlet VIII is connected to the user terminal 5 via the user-side water inlet pipe G. This allows the chilled water inlet pipe A and the chilled water outlet pipe B to circulate only within the unit and not directly participate in heat exchange at the user terminal 5. A user-side water pump 15 is provided on the user-side water inlet pipe G. A separate user-side water circulation system is designed, with chilled water circulating only within the unit and not directly participating in heat exchange at the user terminal. This utilizes indirect heat exchange to meet the user's requirement for high outlet water temperatures.

[0028] Furthermore, outlet AI is connected to chilled water outlet pipeline B via electric butterfly valve B8, and a buffer water tank 9 is installed on chilled water outlet pipeline B near the first inlet V. Because the chilled water in the unit circulates only within the unit, piping space is limited. Adding a buffer water tank can prevent frequent compressor starts and stops and water temperature fluctuations caused by insufficient chilled water circulation. Inlet AI is connected to chilled water inlet pipeline A via electric butterfly valve A6, and a chilled water pump 7 is installed on chilled water inlet pipeline A near electric butterfly valve A6. Outlet BIII is connected to cooling water outlet pipeline D via a manual outlet butterfly valve 12, and inlet BIV is connected to cooling water inlet pipeline C via a manual inlet butterfly valve 10. A cooling water pump 11 is installed on cooling water inlet pipeline C near cooling tower 3.

[0029] Furthermore, a proportional three-way valve 13 is installed between the inlet manual butterfly valve 10 and the cooling water pump 11. This proportional three-way valve 13 is connected to one end of the three-way valve bypass water channel E. The other end of this three-way valve bypass water channel E is connected between the electric butterfly valve B8 and the buffer water tank 9, allowing the chilled water outlet pipe B to bypass the cooling water inlet pipe C. A butterfly valve bypass water channel F is installed between the chilled water pump 7 and the first outlet VI. The other end of this butterfly valve bypass water channel F is connected between the outlet manual butterfly valve 12 and the cooling tower 3, allowing the chilled water inlet pipe A to bypass the cooling water outlet pipe D. An electric butterfly valve C14 is also installed in this butterfly valve bypass water channel F. Electric butterfly valves A6, B8, and C14, along with the proportional three-way valve 13, all automatically open and close based on the ambient temperature, achieving fully automatic switching of the circulating water circuits. The use of proportional three-way valves and electric butterfly valves to achieve automatic switching of water pipes under different ambient temperatures can effectively avoid frequent start and stop of the compressor during cooling throughout the year, greatly reduce the energy consumption of the unit, lower operating costs, and fully automatic control, which is efficient and convenient.

[0030] like Figure 2As shown, when the ambient temperature is higher than the set value T1 (usually set to 20°C), the unit operates under high ambient temperature conditions. At this time, the compressor 16 is running, the chilled water pump 7, the cooling water pump 11, the electric butterfly valve B8 and the electric butterfly valve A6 are all open, the proportional three-way valve 13 and the electric butterfly valve C14 are closed, and the user-side water pump 15 remains open. At this time, the unit uses the screw chiller 19 for cooling.

[0031] like Figure 3 As shown, when the ambient temperature is lower than the set value T1, the unit operates under low ambient temperature conditions. At this time, the compressor 16 stops running, the chilled water pump 7, the electric butterfly valve B8, and the electric butterfly valve A6 are all closed, the cooling water pump 11, the proportional three-way valve 13, and the electric butterfly valve C14 are all opened, and the user-side water pump 15 remains open. At this time, the unit directly uses the cooling tower 3 for natural cooling. Furthermore, when the proportional three-way valve 13 is opened, the valve opening of the proportional three-way valve 13 is automatically controlled according to the water temperature at the first inlet V of the intermediate heat exchanger 4, thereby controlling the amount of water flowing into the first inlet V to meet the water temperature requirement that matches the user-side load. The cooling tower 3 is equipped with a cooling fan 17 and filler 18. The cooling fan 17 automatically starts and stops according to the ambient temperature. When the ambient temperature is higher than the set value T2 (usually set to 10°C), the cooling fan 17 starts. When the ambient temperature is lower than the set value T2, the cooling fan 17 stops. This can further reduce the unit's energy consumption and lower operating costs.

[0032] The working process of this utility model:

[0033] When the unit is in a high ambient temperature condition, that is, the ambient temperature is higher than T1, the unit automatically sets to the compressor cooling mode. At this time, the compressor 16 is running, the chilled water pump 7 is turned on, the cooling water pump 11 is turned on, the electric butterfly valve B8 and the electric butterfly valve A6 are opened, the proportional three-way valve 13 and the electric butterfly valve C14 are closed, and the user side water pump 15 is turned on, forming the following Figure 2 The water circuit shown is shown. Under this cycle, the screw chiller 19 operates normally. Chilled water flows into the evaporator 1's water inlet AⅡ under the action of the chilled water pump 7. After undergoing a primary heat exchange within the evaporator 1 and releasing heat, it flows out of the evaporator 1's water outlet AⅠ. It then passes through the chilled water outlet pipe B and enters the first inlet V of the intermediate heat exchanger 4. There, it undergoes a secondary heat exchange with the user-side circulating water entering through the second inlet VIII of the intermediate heat exchanger 4. The internally circulating chilled water absorbs heat, while the externally circulating user-side circulating water releases heat. The water then flows out of the intermediate heat exchanger 4's first outlet VI and second outlet VII, respectively. The chilled water then flows through the chilled water inlet pipe A and returns to the evaporator 1. The user-side circulating water then passes through the user-side outlet pipe H, undergoes heat exchange with the user terminal 5, and then, driven by the user-side water pump 15, returns to the intermediate heat exchanger 4, repeating the cycle.

[0034] When the unit is in low ambient temperature conditions, that is, the ambient temperature is lower than T1, the unit automatically sets to natural cooling mode. At this time, the compressor 16 stops running, the chilled water pump 7 is turned off, the cooling water pump 11 is turned on, the electric butterfly valve A6 and the electric butterfly valve B8 are closed, the proportional three-way valve 13 and the electric butterfly valve C14 are opened, and the user side water pump 15 is turned on, forming the following Figure 3 The water circulation shown. In this cycle, the screw chiller 19 stops operating. The cooling water in the cooling tower 3, under the action of the cooling water pump 11, flows through the proportional three-way valve 13 to the chilled water outlet pipe B and the condenser 2, respectively. The cooling water flowing to the condenser 2 flows through the cooling water outlet pipe D and back to the cooling tower 3 without undergoing any heat exchange. The cooling water flowing to the chilled water outlet pipe B enters the first inlet V of the intermediate heat exchanger 4, undergoes heat exchange with the user-side circulating water, and then flows out of the first outlet VI of the intermediate heat exchanger 4 to the chilled water inlet pipe A. Then, it flows through the bypass water channel F and the cooling water outlet pipe D and back to the cooling tower 3, completing the water circulation within the unit. After heat exchange with the chilled water in the intermediate heat exchanger 4, the user-side external circulating water flows out of the second outlet VII of the intermediate heat exchanger 4, flows through the user-side outlet pipe H to the user terminal 5, and undergoes heat exchange with the user terminal 5. In this operating mode, the unit can automatically control the valve opening of the proportional three-way valve 13 according to the water temperature at the first inlet V of the intermediate heat exchanger 4, and control the amount of water flowing into the first inlet V, thereby achieving a match between the water temperature of the user-side outlet pipe H and the user-side load.

[0035] In addition, when the ambient temperature is higher than T2, the cooling fan 17 starts, and the cooling water entering the cooling tower 3 relies on the cooling fan 17 to dissipate heat. When the ambient temperature is lower than T2, the cooling fan 17 automatically stops running. Under this condition, the cooling water can achieve the required heat dissipation effect only by relying on the filler 18 in the cooling tower 3.

[0036] The utility model is designed with an independent external user-side high-temperature water circulation system, which uses an intermediate heat exchanger to conduct secondary heat exchange between the host's refrigerated circulating water and the user-side circulating water to achieve indirect cooling, thereby meeting the user's cooling needs for high outlet water temperatures. The proportional three-way valve and electric valve configured in the circulation pipeline can realize automatic switching of water channels in different temperature environments. Under high-temperature environmental conditions, the compressor runs and the host provides cooling. Under low-temperature environmental conditions, the compressor stops running and the water channel automatically switches, realizing cooling only through the unit's own cooling tower. At the same time, the cooling fan in the cooling tower can be automatically started and stopped according to the ambient temperature, maximizing energy-saving benefits. The above design can not only meet the user's demand for high outlet water temperature, but also effectively avoid the frequent start and stop of the compressor during low loads such as transition seasons and winter, greatly reducing system energy consumption and lowering operating costs. In addition, all power components in the entire set of equipment are fully automated by the onboard control system without the need for external control intervention.

[0037] 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. A high refrigeration water temperature dual-cold source integrated screw chiller, characterized by: The invention comprises a screw chiller (19), a cooling tower (3), an intermediate heat exchanger (4) and a plurality of pipelines. The screw chiller (19) comprises an evaporator (1) and a condenser (2), which are connected via a compressor (16) to realize refrigerant circulation. The water inlet A (II) of the evaporator (1) is connected to the first outlet (VI) of the intermediate heat exchanger (4) via a chilled water inlet pipeline (A), and the water outlet A (I) of the evaporator (1) is connected to the first inlet (V) of the intermediate heat exchanger (4) via a chilled water outlet pipeline (B); the water inlet B (IV) of the condenser (2) is connected to the bottom outlet of the cooling tower (3) via a cooling water inlet pipeline (C), and the water outlet B (III) of the condenser (2) is connected to the top inlet of the cooling tower (3) via a cooling water outlet pipeline (D); the second outlet (VII) and the second inlet (VIII) of the intermediate heat exchanger (4) are respectively connected to the user terminal (5) for heat exchange.

2. The high refrigeration water temperature dual-cold source integrated screw chiller according to claim 1, characterized in that: The second outlet (VII) is connected to the user terminal (5) through the user side water outlet pipe (H), and the second inlet (VIII) is connected to the user terminal (5) through the user side water inlet pipe (G), so that the chilled water inlet pipe (A) and the chilled water outlet pipe (B) only circulate water inside the unit and do not directly participate in the heat exchange of the user terminal (5). A user side water pump (15) is provided on the user side water inlet pipe (G).

3. The high refrigeration water temperature dual-cold source integrated screw chiller according to claim 2, characterized in that: The water outlet A (I) is connected to the chilled water outlet pipeline (B) through an electric butterfly valve B (8), and a buffer water tank (9) is provided on the chilled water outlet pipeline (B) near the first inlet (V); the water inlet A (II) is connected to the chilled water inlet pipeline (A) through an electric butterfly valve A (6), and a chilled water pump (7) is provided on the chilled water inlet pipeline (A) near the electric butterfly valve A (6); the water outlet B (III) is connected to the cooling water outlet pipeline (D) through an outlet manual butterfly valve (12), and the water inlet B (IV) is connected to the cooling water inlet pipeline (C) through an inlet manual butterfly valve (10), and a cooling water pump (11) is provided on the cooling water inlet pipeline (C) near the cooling tower (3).

4. The high refrigeration water temperature dual-cold source integrated screw chiller according to claim 3, characterized in that: A proportional three-way valve (13) is provided between the water inlet manual butterfly valve (10) and the cooling water pump (11), and is used to connect one end of the three-way valve bypass water path (E). The other end of the three-way valve bypass water path (E) is connected between the electric butterfly valve B (8) and the buffer water tank (9), so that the chilled water outlet pipeline (B) is bypassed to the cooling water inlet pipeline (C); a butterfly valve bypass water path (F) is provided between the chilled water pump (7) and the first outlet (VI), and the other end of the butterfly valve bypass water path (F) is connected between the water outlet manual butterfly valve (12) and the cooling tower (3), so that the chilled water inlet pipeline (A) is bypassed to the cooling water outlet pipeline (D), and an electric butterfly valve C (14) is provided on the butterfly valve bypass water path (F); the electric butterfly valve A (6), the electric butterfly valve B (8), the electric butterfly valve C (14) and the proportional three-way valve (13) are all automatically switched according to the ambient temperature, so as to realize the fully automatic switching of the circulating water path.

5. The high refrigeration water temperature dual-cold source integrated screw chiller according to claim 4, characterized in that: The cooling tower (3) is provided with a cooling fan (17) and a filler (18). The cooling fan (17) automatically starts and stops according to the ambient temperature. When the ambient temperature is higher than a set value T2, the cooling fan (17) starts, and when the ambient temperature is lower than the set value T2, the cooling fan (17) stops.

6. The high refrigeration water temperature dual-cold source integrated screw chiller according to claim 5, characterized in that: The set value T2 is 10°C.

7. The high refrigeration water temperature dual-cold source integrated screw chiller according to claim 1, characterized in that: The intermediate heat exchanger (4) is a plate heat exchanger or a shell and tube heat exchanger.

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