HK1229874A - Chilled-water cooling system - Google Patents

Description

Chilled water cooling system

Technical Field

The application relates to a chilled water cooling system, in particular to a chilled water cooling system in a refrigerating system of a machine room and a data center, which needs to supply cold for a long time.

Background

In a data center and a machine room refrigerating system, a large amount of refrigerating equipment is required to be used for radiating heat of a server, storage equipment and network equipment. The chilled water system is widely applied to all places needing long-term cooling all the year around, such as large-scale data rooms, exchange rooms and the like. In areas with low air temperature, the design of the refrigerating systems in a plurality of places adopts a natural cooling technology, namely, the refrigerating water system can use a free outdoor cold source without refrigerating by a main refrigerating machine of the refrigerated water by utilizing outdoor low temperature in a transition season or a low-temperature season, so that a large amount of electricity charges are saved for users. In most domestic data centers, the basic supply/return water temperature of a chilled water system is 10 ℃/15 ℃, the outlet air temperature of a tail end air conditioner is 13 ℃, and the time for utilizing a natural cooling technology is short under the condition of the lower supply/return water temperature.

In the design of the existing chilled water natural cooling system, an air-cooled chilled water host is usually combined with a natural cooler (usually a closed cooling tower), as shown in fig. 1, the air-cooled chilled water host 11 is connected in series with the natural cooler 10 and is connected to a water supply/return port of a heat exchanger 12 at the tail end of an air conditioner through a three-way valve 13, and meanwhile, the three-way valve 13 is also connected to a pipeline in series connection between the air-cooled chilled water host 11 and the natural cooler 10 through a valve 14.

In the mechanical cooling mode, the outdoor air temperature exceeds the return water temperature by 20 ℃, if the chilled water still passes through the natural cooler (10), the chilled water becomes heat absorption rather than heat dissipation, so the three-way valve 13 is adjusted to be in the bypass mode, the valve 14 is opened, the return water of the heat exchanger 12 at the tail end of the air conditioner does not pass through the natural cooler 10, the air-cooled chilled water host 11 and the air-cooled chilled water host 11 start refrigeration, and the chilled water at 20 ℃ is converted into the chilled water at 15 ℃ through the whole mechanical refrigeration process (including the work of a compressor, the heat extraction of a condenser and the like) and is sent back to the heat exchanger 12 at the.

In the natural cooling mode, the outdoor air temperature must be lower than the water supply temperature, for example, the outdoor air temperature is 12 ℃, the water supply temperature is 15 ℃, after the load heat is absorbed by the heat exchanger 12 at the end of the air conditioner, the temperature of the 15 ℃ chilled water is raised to 20 ℃, the three-way valve 13 is adjusted to pass through the natural cooler 10, the 20 ℃ chilled water is firstly cooled to 15 ℃ by the outdoor natural cooler 10, then passes through the air-cooled chilled water host 11 (but the air-cooled chilled water is not required to be mechanically cooled when the air-cooled chilled water is shut down 11), and then is sent back to the heat exchanger 12 at the end of the air conditioner to.

In a partial natural cooling mode, a loop is the same as natural cooling, but the temperature of outdoor air is increased, the temperature of chilled water cannot reach 15 ℃ after passing through the natural cooler 10, and the chilled water is cooled to 15 ℃ only by starting refrigeration through the air-cooled chilled water host 11 and the air-cooled chilled water host 11 to supplement the refrigeration, and then is sent back to the heat exchanger 12 at the tail end of the air conditioner.

The temperature of a cold channel designed in most of the existing data machine rooms is low, and when a water side natural cooling system is designed, according to the temperature of water supply and return at 15 ℃/20 ℃, the temperature of the water supply and return generally reaches about 10 ℃ when natural cooling (free cooling) is started, the temperature of the water supply and return generally needs about 18 ℃ when the natural cooling (partial free cooling) is started, and the temperature of the water supply and return generally exceeds 18 ℃, and a mechanical cooling mode (mechanical cooling) is started.

Therefore, the existing chilled water loop always passes through the chilled water main engine, and the chilled water loop selectively enters the natural cooler through the control of the three-way valve, namely the main chilled water main engine, and is cooled by the auxiliary of the natural cooler. With the development of information equipment such as an IT server, the requirement of the equipment such as the server on the temperature of the inlet air is gradually relaxed, for example, in the current latest ASHRAE (american society of heating and air conditioning engineers) published TC9,9 specification, the temperature range of the inlet air is recommended to be 18-27 ℃. Along with the increase of the inlet air temperature acceptable by the server, the temperature of the supply and return water of the chilled water can be higher and higher during the design of the refrigerating system, and the defect that the natural cooling design of the traditional main chilled water host machine is not energy-saving is more obvious.

Disclosure of Invention

The invention provides a chilled water cooling system, which aims to solve the problem that the existing chilled water cooling system is not energy-saving enough.

The invention provides a chilled water cooling system, which comprises a natural cooling loop and a mechanical cooling loop, wherein the natural cooling loop is formed by connecting a main chilled water pump, a pipeline and a tail end heat exchanger in series, the mechanical cooling loop is formed by connecting a main chilled water pump, an auxiliary chilled water pump and a pipeline in series, and the tail end heat exchanger is arranged at a position needing to provide refrigeration.

Preferably, said controllably conductive-isolating device is a valve located on the mechanical cooling circuit.

Preferably, the controllable conduction-isolation device is a three-way mixing valve located at the connection of the mechanical cooling circuit and the natural cooling circuit.

Preferably, the chilled water main machine is a water-cooling chilled water main machine.

Preferably, the free cooler is a dry cooler.

Preferably, the condensation side of the water-cooled chilled water main machine is cooled by a cooling tower.

Preferably, the cooling tower adopted by the condensation side of the water-cooling chilled water main machine is a closed cooling tower.

Preferably, the free cooler is a cooling tower.

Preferably, the cooling tower as the natural cooler is a closed cooling tower.

Preferably, the condensation side cooling tower is merged into a natural cooling loop through a pipeline and a first valve (2V1) and a second valve (2V2) which are respectively positioned at two ends of the condensation side cooling tower, and in the case of natural cooling, the cooling tower at the condensation side of the water-cooling chilled water main machine can be used in series by controlling the on/off states of the first valve and the second valve except the cooling tower which mainly uses the natural cooling loop.

Preferably, the first valve (2V1) and the second valve (2V2) are located at the junction of the natural cooling circuit and the mechanical cooling circuit.

Preferably, the condensation side of the water-cooled chilled water main engine adopts a heat exchanger which takes lake water/seawater or other cold water resources as a cooling medium.

Preferably, the heat exchanger is a plate heat exchanger.

Preferably, the natural cooler is a heat exchanger using lake water/seawater or other cold water resources as a cooling medium.

Preferably, the heat exchanger as a free cooler is a plate heat exchanger.

Preferably, the heat exchanger high-temperature fluid access side of the condensation side of the water-cooled chilled water main unit, which uses lake water/seawater or other cold water resources as cooling media, is merged into the natural cooling loop through a pipeline and a third valve (4V3) and a fourth valve (4V4) which are respectively located at two ends of the high-temperature fluid access side of the heat exchanger at the condensation side of the water-cooled chilled water main unit, and under the condition of natural cooling, except for the heat exchanger which mainly uses the lake water/seawater or other cold water resources as cooling media of the natural cooling loop, the heat exchanger which uses the lake water/seawater or other cold water resources as cooling media at the condensation side of the water-cooled chilled water main unit can be used in series by controlling the on/off states of the third valve (4V3) and the fourth valve (4V4) which are respectively located at two ends of the high-temperature fluid access side of the heat exchanger at the.

Preferably, the third valve (4V3) and the fourth valve (4V4) at the two ends of the high-temperature fluid side of the condensation side heat exchanger of the water-cooled chilled water main unit are positioned at the joint of the natural cooling loop and the mechanical cooling loop

Preferably, the chilled water main machine is an air-cooled chilled water main machine.

Preferably, the free cooler is a cooling tower.

Preferably, the cooling tower is a closed cooling tower.

Preferably, the natural cooler is a heat exchanger using lake water/seawater or other cold water resources as a cooling medium.

Preferably, the heat exchanger is a plate heat exchanger.

Preferably, the free cooler is a dry cooler.

Preferably, the chilled water main machine is an air-cooled chilled water main machine, the controllable conduction-isolation device is a heat exchanger, two ends of one side of the heat exchanger are connected in series with a natural cooling loop, the other side of the heat exchanger is connected in series with a cold accumulation device and is connected with a water supply/return end of a mechanical cooling loop, and auxiliary cooling of the mechanical cooling loop can be controlled by starting a chilled water auxiliary pump.

Preferably, the heat exchanger is a plate heat exchanger.

Preferably, the free cooler is a cooling tower.

Preferably, the free cooler is a closed cooling tower.

Preferably, the natural cooler is a heat exchanger using lake water/seawater or other cold water resources as a cooling medium.

Preferably, the heat exchanger as a free cooler is a plate heat exchanger.

Preferably, the free cooler is a dry cooler.

Preferably, the end heat exchanger is a heat exchanger at an air conditioner end or a heat exchanger of a liquid cooling server.

Compared with the prior art, the invention has the following advantages:

the natural cooler is not connected with a chilled water main machine in series to form a chilled water loop as in the prior art, but forms a natural cooling loop and a mechanical cooling loop with the chilled water main machine respectively; and the natural cooling loop is used as a main chilled water loop and connected to the tail end heat exchanger, the mechanical cooling loop is merged into the natural cooling loop through the conduction-isolation device, and the mechanical cooling loop can be controlled to carry out auxiliary cooling through the conduction-isolation device.

After the technical scheme that this application provided is adopted, when adopting the natural cooling mode, mechanical cooling circuit is isolated, and the refrigerated water need not pass through the refrigerated water host computer again, only through the natural cooling circuit, just can provide the refrigerated water that satisfies its temperature requirement for end heat exchanger. The technical scheme provided by the invention can mainly use the natural cooling mode in more areas and assist in adopting the mechanical cooling mode or partial natural cooling mode, thereby achieving the effect of saving energy under the condition of ensuring the cooling requirement.

According to the technical scheme provided by the invention, the mechanical cooling loop can be conducted in a partial natural cooling mode, and the chilled water main engine is started to carry out auxiliary cooling on the mechanical cooling loop.

Therefore, the chilled water main engine with less or even no mechanical cooling loop can be started, so that the energy is further saved, and the operation and maintenance cost of equipment and a system is reduced.

Drawings

FIG. 1 is a schematic view of the working principle of a chilled water cooling system of an existing air-cooled chilled water main unit combined with a natural cooler;

FIG. 2 is a schematic view of the natural cooling of the chilled water cooling system with the air-cooled chilled water main unit combined with the cooling tower according to the first embodiment of the present invention;

FIG. 3 is a schematic view of a portion of the natural cooling of the chilled water cooling system with the air-cooled chilled water main unit combined with the cooling tower according to the first embodiment of the present invention;

FIG. 4 is a schematic view of the natural cooling of the chilled water cooling system with a water-cooled chilled water main unit combined with a cooling tower according to the second embodiment of the present invention;

FIG. 5 is a schematic view of a part of a chilled water cooling system with a water-cooled chilled water main unit combined with a cooling tower according to a second embodiment of the present invention;

FIG. 6 is a schematic diagram of a chilled water cooling system using a heat exchanger of lake/sea water or other cold water resources as a cooling medium as a free cooler according to a third embodiment of the present invention;

FIG. 7 is a schematic diagram of the natural cooling of a chilled water cooling system in which both the mechanical cooling circuit and the natural cooling circuit employ heat exchangers using lake/seawater or other cold water resources as cooling media in accordance with a fourth embodiment of the present invention;

FIG. 8 is a schematic diagram of a part of the natural cooling of a chilled water cooling system in which a heat exchanger using lake/seawater or other cold water resources as a cooling medium is employed in both a mechanical cooling circuit and a natural cooling circuit according to a fourth embodiment of the present invention;

FIG. 9 is a schematic diagram of a chilled water cooling system using a heat exchanger to isolate a natural cooling loop from an auxiliary cooling loop in accordance with a fifth embodiment of the invention.

10 in fig. 1 to 9: a natural cooler; 11: an air-cooled chilled water main unit; 12: heat exchanger at air conditioner end 13: a three-way mixing valve; 14: a valve; 120. 520, the method comprises the following steps: a cooling tower; 220: a first cooling tower; 242: a second cooling tower; 121. 321, 521: an air-cooled chilled water main unit; 122. 222, 322, 422, 522: a heat exchanger at the end of the air conditioner; 123. 223, 523: a first differential pressure bypass branch; 124. 224, 324, 424, 524: a second differential pressure bypass branch; 1P1, 2P1, 3P1, 4P1, 5P 1: a chilled water main pump; 1P2, 2P2, 3P2, 4P2, 5P 2: a chilled water assist pump; 1V20, 2V20, 3V20, 4V 20: a three-way mixing valve; 241. 441: water-cooling the chilled water main engine; 2411. 4411: an evaporator; 2412. 4412: a condenser; 2P3, 4P 3: a cooling water pump; 2V 1: a first valve; 2V 2: a second valve; 360: a heat exchanger; 460: a first heat exchanger; 472: a second heat exchanger; 365. 465: lake/sea or other cold water resources; 4V 3: a third valve; 4V 4: a fourth valve; 593: a heat exchanger; 594: a cold storage device;

Detailed Description

The following detailed description of certain preferred embodiments of the present invention is provided in conjunction with the accompanying drawings to facilitate a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make and use the invention without departing from the spirit and scope of the present invention.

The first embodiment of the invention provides a chilled water cooling system which adopts a natural cooling loop as a main cooling loop and an air cooling loop as an auxiliary cooling loop; fig. 2 and 3 respectively show the chilled water cooling system; wherein, fig. 2 shows a schematic diagram of the chilled water cooling system adopting a natural cooling mode; fig. 3 shows a schematic diagram of the chilled water cooling system in a partial natural cooling mode.

As shown in fig. 2 and 3, the chilled water cooling system includes a natural cooling circuit and a mechanical cooling circuit. The natural cooling loop comprises a cooling tower 120, a chilled water main pump 1P1, a pipeline, a first differential pressure bypass branch 123 and a heat exchanger 122 at the tail end of an air conditioner which are connected; the mechanical cooling loop adopts an air cooling mode and comprises an air-cooled chilled water main machine 121, a chilled water auxiliary pump 1P2, a valve 1V20 and a second differential pressure bypass branch 124 which are connected. Wherein, the cooling tower 120 preferably adopts a closed cooling tower such as a spray closed cooling tower, and the valve 1V20 preferably adopts a three-way mixing valve. The air conditioning terminal heat exchanger 122 may also be a liquid cooling server heat exchanger or any other terminal heat exchanger.

The connection structure of the chilled water cooling system will be described in detail below.

In the natural cooling loop, one end of a cooling tower 120 is connected in series with a primary chilled water pump 1P1 through a pipeline and then is connected to one end of a heat exchanger 122 at the tail end of the air conditioner, the other end of the heat exchanger 122 at the tail end of the air conditioner is connected to one end, which is not connected with the primary chilled water pump P1, of the cooling tower 120 through a pipeline, and the loop forms a main loop of the natural cooling loop. To provide overpressure protection for the cooling tower 120, the piping on both sides of the cooling tower 120 is connected in parallel with a first differential pressure bypass branch 123.

In the mechanical cooling circuit, both ends of the air-cooled chilled water main unit 121 are connected to a pipeline on one side connected between the cooling tower 120 of the natural cooling circuit and the heat exchanger 122 at the end of the air conditioner through pipelines, one end of the pipeline is connected to the main pipeline through the three-way mixing valve 1V20, and the chilled water auxiliary pump 1P2 is connected in series in the pipeline.

The chilled water cooling circuit has two working modes, namely a natural cooling mode and a partial natural cooling mode.

In the natural cooling mode, as shown in fig. 2, the three-way mixing valve 1V20 opens only the main line of the natural cooling circuit connecting one end of the cooling tower 120 and one end of the heat exchanger 122 at the air conditioning end, and the line of the mechanical cooling circuit and the main line are blocked by the three-way mixing valve 1V 20. In the natural cooling mode, the primary chilled water pump 1P1 operates, and the chilled water absorbs heat in the heat exchanger 122 at the air conditioner end by the pressure provided by the primary chilled water pump 1P1, and then returns to the other end of the heat exchanger 122 at the air conditioner end through the cooling tower 120. When the chilled water passes through the cooling tower 120, the chilled water discharges the absorbed heat to the outdoor environment through the cooling pipeline of the cooling tower 120, and the temperature of the chilled water flowing back to the heat exchanger 122 at the end of the air conditioner is reduced to a proper temperature, so that the chilled water can take away the heat as a refrigerant in the heat exchanger 122 at the end of the air conditioner again. In this operation mode, since the three-way mixing valve 1V20 is closed, the chilled water passes through the cooling tower 120 only, and does not pass through the chilled water auxiliary refrigeration circuit for refrigeration (shown by a dotted line in fig. 2), and the air-cooled chilled water main unit 121 does not operate.

In the partial natural cooling mode, as shown in fig. 3, the three-way mixing valve 1V20 opens the main line of the natural cooling circuit connecting one end of the cooling tower 120 and one end of the heat exchanger 122 at the air conditioning end, and simultaneously opens the mechanical cooling circuit and the main line; the chilled water main pump 1P1 and the chilled water auxiliary pump 1P2 are simultaneously started to drive the chilled water to flow in the loop. After the chilled water is first cooled by the cooling tower 120, part of the chilled water (for example, 20%) passes through the air-cooled chilled water main unit 121 under the pressure provided by the chilled water auxiliary pump 1P2, is cooled by the air-cooled chilled water main unit 121, is mixed with the chilled water in the main pipeline through the three-way mixing valve 1V20 after being cooled, obtains a proper temperature, and then returns to the heat exchanger 122 at the end of the air conditioner.

In the technical scheme provided by the first embodiment, the main cooling tower enables the main chilled water loop to use natural cooling all the time, and the air-cooled chilled water main machine is only used for auxiliary cooling. In some places, the closed cooling tower of a natural cooling loop can be directly used without a mechanical cooling loop under allowable climatic conditions, so that the investment and the energy consumption of the system can be greatly reduced.

A second embodiment of the present invention provides a chilled water cooling system in which a natural cooling circuit using a cooling tower as a natural cooler is used as a main cooling circuit, and a water-cooled mechanical cooling circuit using a cooling tower as a cooler is used as an auxiliary cooling circuit. Wherein, the natural cooling loop is used as a main loop, and the mechanical cooling loop is used for auxiliary cooling. Fig. 4 and 5 show the chilled water cooling system, respectively; wherein, fig. 4 is a schematic view showing the working principle of the chilled water cooling system adopting a natural cooling mode; fig. 5 is a schematic diagram illustrating the working principle of the chilled water cooling system in a partial natural cooling mode.

As shown in fig. 4 and 5, the chilled water cooling system includes a natural cooling loop and a mechanical cooling loop. The natural cooling loop comprises a first cooling tower 220, a chilled water main pump 2P1, a pipeline, a first differential pressure bypass branch 223 and a heat exchanger 222 at the tail end of an air conditioner; the mechanical cooling loop adopts a water cooling mode and comprises a water-cooling chilled water host 241, an evaporator 2411 and a condenser 2412 thereof, a three-way mixing valve 2V20, a chilled water auxiliary pump 2P2, a cooling water pump 2P3, a second cooling tower 242 and pipelines; in addition, the first valve 2V1, the second valve 2V2 and the connecting pipeline are also included. The first cooling tower 220 and the second cooling tower 242 are preferably closed cooling towers such as spray closed cooling towers.

The connection structure of the chilled water cooling system will be described in detail below.

In the natural cooling loop, one end of a first cooling tower 220 is connected in series with a primary chilled water pump 2P1 through a pipeline and then is connected to one end of a heat exchanger 222 at the tail end of the air conditioner, the other end of the heat exchanger 222 at the tail end of the air conditioner is connected to one end, which is not connected with the primary chilled water pump 2P1, of the first cooling tower 220 through a pipeline, and the loop forms a main loop of the natural cooling loop. To provide overpressure protection for the first cooling tower 220, piping on both sides of the first cooling tower 220 is coupled in parallel with a first differential pressure bypass branch 223.

In the mechanical cooling circuit, both ends of an evaporator 2411 of the water-cooling chilled water main machine 241 are connected to a pipeline on one side connected between a first cooling tower 220 of the natural cooling circuit and a heat exchanger 222 at the tail end of the air conditioner through pipelines, one end of the pipeline is connected to the main pipeline through the three-way mixing valve 2V20, and the chilled water auxiliary pump 2P2 is connected in series in the pipeline. In order to provide overpressure protection for the water-cooled chilled water main machine 241, the pipelines on two sides of the water-cooled chilled water main machine 241 are connected in parallel with a second pressure difference bypass branch 224. Both ends of the condenser 2412 of the water-cooled chilled water main machine 241 are connected to both ends of the second cooling tower 242 through pipelines, and the cooling water pump 2P3 is connected in series in the pipelines. One end of the second cooling tower 242 is connected to a pipeline connected between the natural cooling loop first cooling tower 220 and the three-way mixing valve 2V20 through a first valve 2V1 and a pipeline, and the other end of the second cooling tower 242 is connected to a pipeline connected between the three-way mixing valve 2V20 and the heat exchanger 222 at the end of the air conditioner through a second valve 2V2 and a pipeline.

The chilled water cooling system has two working modes, namely a natural cooling mode and a partial natural cooling mode.

In the natural cooling mode, as shown in fig. 4, the three-way mixing valve 2V20 is closed, the three-way mixing valve 2V20 blocks a line from the end of the natural cooling circuit not connected to the chilled water main pump 2P1 to the end of the heat exchanger 222 at the air conditioning end, the three-way mixing valve 2V20 blocks a line from the mechanical cooling circuit, and the first valve 2V1 and the second valve 2V2 are opened. In the natural cooling mode, the primary chilled water pump 2P1 operates, and under the pressure provided by the primary chilled water pump 2P1, the chilled water absorbs heat in the heat exchanger 222 at the air conditioner end, passes through the first cooling tower 220, and then returns to the other end of the heat exchanger 222 at the air conditioner end through the first valve 2V1, the second cooling tower 242, and the second valve 2V 2. When the chilled water passes through the first cooling tower 220 and the second cooling tower 242, the chilled water discharges the absorbed heat to the outdoor environment through the cooling pipes of the first cooling tower 220 and the second cooling tower 242, and the temperature of the chilled water flowing back to the heat exchanger 222 at the air conditioner end is reduced to a proper temperature, so that the chilled water can take away the heat as a refrigerant in the heat exchanger 222 at the air conditioner end again. In this operation mode, since the three-way mixing valve 2V20 is closed and the first valve 2V1 and the second valve 2V2 are opened, the chilled water is cooled only by the first cooling tower 220 and the second cooling tower 242 without being cooled by the chilled water auxiliary cooling circuit (shown by a dotted line in fig. 4), and in this operation mode, the chilled water auxiliary pump 2P2 and the water-cooled chilled water main machine 241 do not operate.

In the partial free cooling mode, as shown in fig. 5, the first valve 2V1 and the second valve 2V2 are closed and the lines connected thereto are not operated (shown in phantom in fig. 5). The three-way mixing valve 2V20 is communicated with a main pipeline of a natural cooling circuit which is connected with one end of a first cooling tower 220 and one end of a heat exchanger 222 at the tail end of an air conditioner, and is communicated with the mechanical cooling circuit; the chilled water main pump 2P1 and the chilled water auxiliary pump 2P2 are simultaneously started to drive the chilled water to flow in the loop. After the chilled water is first cooled by the first cooling tower 220, a part of the chilled water (for example, 20%) passes through the evaporator 2411 of the water-cooled chilled water main unit 241 under the pressure provided by the chilled water auxiliary pump 2P2, is cooled by the water-cooled chilled water main unit 241, is mixed with the chilled water in the main pipeline through the three-way mixing valve 2V20 after being cooled, obtains a proper temperature, and returns to the heat exchanger 222 at the end of the air conditioner. The condenser 2412 side of the water-cooled chilled water main unit is driven by a cooling water pump 2P3 to cool the water by the second cooling tower 242.

In the technical scheme that this second embodiment provided, because mechanical cooling circuit adopts the water-cooling refrigerated water host computer that is higher than air-cooling refrigerated water host computer energy efficiency ratio, supplementary cooling efficiency is higher, and adopt the cooling tower cooling with natural cooling circuit is the same, can also add the heat-sinking capability of water-cooling refrigerated water host computer condensation side cooling tower to natural cooling circuit under the natural cooling mode, so not only can realize mainly adopting natural cooling circuit cooling, the supplementary effect that adopts water-cooling refrigerator water host computer cooling, and natural cooling time and ability all obtain further reinforcing, thereby can obtain improvement cooling efficiency, reduce the effect of energy consumption.

The third embodiment of the invention provides a chilled water cooling system which adopts a heat exchanger taking lake water/seawater or other cold water resources as a cooling medium as a natural cooler and adopts an air-cooled chilled water main machine as a mechanical cooler for auxiliary cooling. Fig. 6 is a schematic diagram of the working principle of the system.

As shown in fig. 6, the chilled water cooling system includes a natural cooling loop and a mechanical cooling loop. The natural cooling loop comprises a heat exchanger 360 taking lake water/seawater or other cold water resources as cooling media, a chilled water main pump 3P1, a lake water/seawater or other cold water resources 365, pipelines and a heat exchanger 322 at the tail end of an air conditioner. The mechanical cooling loop comprises an air-cooled chilled water main machine 321, a chilled water auxiliary pump 3P2, a three-way mixing valve 3V20, a second differential pressure bypass branch 324 and a pipeline. The heat exchanger 360 is preferably a plate heat exchanger.

The connection structure of the chilled water cooling system will be described in detail below.

In the natural cooling loop, one end of the high-temperature fluid side of a heat exchanger 360 taking lake water/seawater or other cold water resources as cooling media is connected in series with a primary chilled water pump 3P1 through a pipeline and then is connected to one end of a heat exchanger 322 at the tail end of the air conditioner, the other end of the heat exchanger 322 at the tail end of the air conditioner is connected to one end of the high-temperature fluid side of the heat exchanger 360 taking the lake water/seawater or other cold water resources as cooling media, which is not connected with the primary chilled water pump 3P1, through a pipeline, and the loop forms a main loop of the natural cooling loop. Both ends of the cryogenic fluid side of the heat exchanger 360, which uses lake water/sea water or other cold water resources as cooling media, are connected to the lake water/sea water or other cold water resources 365 through pipelines.

In the mechanical cooling loop, two ends of an air-cooled chilled water main machine 321 are connected to a pipeline on one side connected between a heat exchanger 360 of the natural cooling loop and a heat exchanger 322 at the tail end of the air conditioner through pipelines, one end of the pipeline is connected to the main pipeline through the three-way mixing valve 3V20, and the chilled water auxiliary pump 3P2 is connected in the pipeline in series. The pipelines on the two sides of the air-cooled chilled water main machine 321 are connected in parallel with a second differential pressure bypass branch 324.

The chilled water cooling system has two working modes, namely a natural cooling mode and a partial natural cooling mode.

In the natural cooling mode, the three-way mixing valve 3V20 opens only the natural cooling circuit main line connecting one end of the heat exchanger 360 with lake/sea water or other cold water resources as a cooling medium and one end of the heat exchanger 322 at the air conditioning end, and the line of the mechanical cooling circuit and the main line are blocked by the three-way mixing valve 3V 20. In the natural cooling mode, the primary chilled water pump 3P1 operates, and the chilled water absorbs heat in the heat exchanger 322 at the air conditioner end under the pressure provided by the primary chilled water pump 3P1, and then returns to the other end of the heat exchanger 322 at the air conditioner end through the heat exchanger 360 using lake water/seawater or other cold water resources as a cooling medium. When the chilled water passes through the heat exchanger 360 using the lake water/seawater or other cold water resources as the cooling medium, the chilled water discharges the absorbed heat to the lake water/seawater or other cold water resources 365 through the heat exchanger 360 using the lake water/seawater or other cold water resources as the cooling medium, and the temperature of the chilled water flowing back to the heat exchanger 322 at the air conditioner end again is reduced to a proper temperature, so that the heat can be taken away as a refrigerant in the heat exchanger 322 at the air conditioner end again. In this mode of operation, with the three-way mixing valve 3V20 closed, the chilled water is cooled only by the heat exchanger 360 with lake/sea water or other cold water resources as the cooling medium, and not by the auxiliary cooling of the mechanical cooling circuit in which the air-cooled chilled water main engine is located. The chilled water auxiliary pump 3P2 and the air-cooled chilled water main machine 321 do not work.

In a partial natural cooling mode, the three-way mixing valve 3V20 is communicated with a natural cooling loop main pipeline which is connected with one end of the high-temperature fluid side of a heat exchanger 360 taking lake water/seawater or other cold water resources as cooling media and one end of a heat exchanger 322 at the tail end of an air conditioner, and is communicated with the mechanical cooling loop; the chilled water main pump 3P1 and the chilled water auxiliary pump 3P2 are simultaneously started to drive the chilled water to flow in the loop. After the chilled water is first cooled by the heat exchanger 360 using lake water/seawater or other cold water resources as a cooling medium, part (for example, 20%) of the chilled water passes through the air-cooled chilled water main unit 321 under the pressure provided by the chilled water auxiliary pump 3P2, is cooled by the air-cooled chilled water main unit 321, is mixed with the chilled water in the main pipeline through the three-way mixing valve 3V20 after being cooled, obtains a proper temperature, and then returns to the heat exchanger 322 at the end of the air conditioner.

In the technical solution provided by the third embodiment, not only the natural cooling loop is mainly adopted and the air-cooled chiller water main machine is adopted for cooling, but also the heat exchanger using lake water/seawater or other cold water resources as a cooling medium is adopted as a natural cooler, and the natural cooling capacity is further enhanced because the heat conductivity coefficient of water is higher than that of air. The effect of improving the cooling efficiency is achieved.

A fourth embodiment of the present invention provides a chilled water cooling system that employs a heat exchanger using lake/sea water or other cold water resources as a cooling medium as a natural cooler and a water-cooled chilled water main unit as a mechanical cooler. The condensation side of the water-cooled chilled water main engine is also cooled by a heat exchanger which takes lake water/seawater or other cold water resources as a cooling medium. FIG. 7 is a schematic view of the natural cooling principle of the chilled water cooling system; fig. 8 is a schematic view of a part of the natural cooling principle of the chilled water cooling system.

As shown in fig. 7 and 8, the chilled water cooling system includes a natural cooling circuit and a mechanical cooling circuit. The natural cooling loop comprises a first heat exchanger 460 taking lake water/seawater or other cold water resources as cooling media, a chilled water primary pump 4P1, a lake water/seawater or other cold water resources 465, pipelines and a heat exchanger 422 at the tail end of an air conditioner. The mechanical cooling loop comprises a water-cooled chilled water host 441 and an evaporator 4411 and a condenser 4412 thereof, a chilled water auxiliary pump 4P2, a three-way mixing valve 4V20, a second pressure difference bypass branch 424, a cooling water pump 4P3, a second heat exchanger 472 taking lake water/seawater or other cold water resources as cooling media, lake water/seawater or other cold water resources 465 and pipelines. In addition, the device also comprises a third valve 4V3, a fourth valve 4V4 and a connecting pipeline. The first heat exchanger 460 and the second heat exchanger 472 are preferably plate heat exchangers.

The connection structure of the chilled water cooling system will be described in detail below.

In the natural cooling loop, one end of the high-temperature fluid side of the heat exchanger 460 using lake water/seawater or other cold water resources as cooling media is connected in series with the primary chilled water pump 4P1 through a pipeline and then is connected to one end of the heat exchanger 422 at the air conditioner end, the other end of the heat exchanger 422 at the air conditioner end is connected to one end of the first heat exchanger 460 using lake water/seawater or other cold water resources as cooling media, which is not connected with the primary chilled water pump 4P1, through a pipeline, and the loop forms the main loop of the natural cooling loop. The two ends of the low-temperature fluid side of the first heat exchanger 460 which takes lake water/seawater or other cold water resources as cooling media are connected to the lake water/seawater or other cold water resources 465 through pipelines.

In the mechanical cooling loop, both ends of an evaporator 4411 of a water-cooled chilled water main machine 441 are connected to a pipeline on one side of the natural cooling loop, which is connected between a first heat exchanger 460 using lake water/seawater or other cold water resources as a cooling medium and a heat exchanger 422 at the tail end of the air conditioner through pipelines, one end of the pipeline is connected to the main pipeline through the three-way mixing valve 4V20, and the chilled water auxiliary pump 4P2 is connected in series in the pipeline. And the pipelines on the two sides of the evaporator 4411 of the water-cooled chilled water main unit 441 are connected with a second pressure difference bypass branch 424 in parallel. Both ends of the condenser 4412 of the water-cooled chilled water main 441 are connected to both ends of the high-temperature fluid side of the second heat exchanger 472 using lake water/seawater or other cold water resources as cooling media through pipelines, and the cooling water pump 4P3 is connected in series in the pipelines. One end of the high-temperature fluid side of the second heat exchanger 472 which takes the lake water/seawater or other cold water resources as the cooling medium is connected to the pipeline connected between the first heat exchanger 460 which takes the lake water/seawater or other cold water resources as the cooling medium and the three-way mixing valve 4V20 of the natural cooling loop through the third valve 4V3 and the pipeline, and the other end of the high-temperature fluid side of the second heat exchanger 472 which takes the lake water/seawater or other cold water resources as the cooling medium is connected to the pipeline connected between the three-way mixing valve 4V20 and the heat exchanger 422 at the tail end of the air conditioner through the fourth valve 4V4 and the pipeline. The cryogenic fluid side of the second heat exchanger 472, with the lake/sea or other cold water resource as the cooling medium, is connected by piping to the lake/sea or other cold water resource 465.

The chilled water cooling system has two working modes, namely a natural cooling mode and a partial natural cooling mode.

In the natural cooling mode, as shown in fig. 7, the three-way mixing valve 4V20 is closed, the three-way mixing valve 4V20 blocks a line from the end of the natural cooling circuit not connected to the chilled water main pump 4P1 to the end of the heat exchanger 422 at the air conditioning end, the three-way mixing valve 4V20 blocks a line from the mechanical cooling circuit, and the third valve 4V3 and the fourth valve 4V4 are opened. In the natural cooling mode, the primary chilled water pump 4P1 operates, and under the pressure provided by the primary chilled water pump 4P1, the chilled water absorbs heat in the heat exchanger 422 at the air conditioner end, passes through the first heat exchanger 460 using lake water/seawater or other cold water resources as a cooling medium, passes through the third valve 4V3 and the second heat exchanger 472 using lake water/seawater or other cold water resources as a cooling medium, and returns to the other end of the heat exchanger 422 at the air conditioner end through the fourth valve 4V 4. When the chilled water passes through the first heat exchanger 460 and the second heat exchanger 472, the absorbed heat is absorbed by the lake/sea or other cold water resources 465, and the temperature of the chilled water flowing back to the heat exchanger 422 at the air conditioner terminal is reduced to a suitable temperature, so that the chilled water can be used as a refrigerant to remove heat in the heat exchanger 422 at the air conditioner terminal again. In this operation mode, since the three-way mixing valve 4V20 is closed and the third valve 4V3 and the fourth valve 4V4 are opened, the chilled water is cooled only by the first heat exchanger 460 and the second heat exchanger 472 using lake water/seawater or other cold water resources as cooling media, and is not cooled by the auxiliary cooling of the mechanical cooling loop in which the water-cooled chilled water main unit 441 is located (shown by a dotted line in fig. 7). The chilled water auxiliary pump 4P2 and the water-cooled chilled water main unit 441 do not work.

In the partial natural cooling mode, as shown in fig. 8, the three-way mixing valve 4V20 opens the natural cooling circuit main line connecting the end of the first heat exchanger 460 using lake/sea water or other cold water resources as a cooling medium and the end of the heat exchanger 422 at the air conditioning end, simultaneously opens the mechanical cooling circuit to the main line, and the third valve 4V3 and the fourth valve 4V4 are closed and the line connected thereto is not operated (shown by a dotted line in fig. 8). The chilled water main pump 4P1 and the chilled water auxiliary pump 4P2 are started simultaneously to drive the chilled water to flow in the loop. After the chilled water is first cooled by the first heat exchanger 460 using lake water/seawater or other cold water resources as a cooling medium, part of the chilled water (for example, 20%) passes through the evaporator 4411 of the water-cooled chilled water main unit 441 under the pressure provided by the chilled water auxiliary pump 4P2 and is cooled by the water-cooled chilled water main unit 441, and after cooling, the chilled water is mixed with the chilled water in the main pipeline through the three-way mixing valve 4V20 to obtain a proper temperature and then is returned to the heat exchanger 422 at the end of the air conditioner. The cooling water pump 4P3 is turned on and the condenser 4412 of the water-cooled chilled water main is cooled by the second heat exchanger 472 using lake/sea water or other cold water resources as a cooling medium.

In the technical scheme provided by this fourth embodiment, not only can the natural cooling circuit be mainly used for cooling, but also the water-cooling refrigerating machine water main machine is used for cooling in an auxiliary manner, because the water-cooling refrigerating water main machine with higher energy efficiency ratio than the air-cooling refrigerating water main machine is used, the auxiliary cooling efficiency of the mechanical cooling circuit is improved, furthermore, the water-cooling refrigerating water main machine and the natural cooling circuit are both cooled by the heat exchanger which takes lake water/seawater or other cold water resources with higher heat conductivity than air as a cooling medium, and the heat dissipation capacity of the heat exchanger on the condensation side of the water-cooling refrigerating water main machine can be added into the natural cooling circuit in a natural cooling mode, so that the natural cooling capacity is greatly improved. The effects of improving the cooling efficiency and reducing the energy consumption are achieved.

A fifth embodiment of the present invention provides a chilled water cooling system that employs a heat exchanger to isolate a natural cooling loop from a mechanical cooling loop. Fig. 9 is a schematic diagram of the working principle of the system.

As shown in fig. 9, the chilled water cooling system includes a natural cooling loop using a cooling tower to cool and a mechanical cooling loop using an air-cooled chilled water main unit to cool. The natural cooling loop comprises a cooling tower 520, a first pressure difference bypass branch 523, a primary chilled water pump 5P1, a high-temperature fluid side of a heat exchanger 593, a pipeline and a heat exchanger 522 at the tail end of an air conditioner; the mechanical cooling loop comprises a low-temperature fluid side of a heat exchanger 593, an air-cooled chilled water main unit 521, a second differential pressure bypass branch 524, a chilled water auxiliary pump 5P2, a cold accumulation device 594 and a pipeline. The heat exchanger 593 preferably adopts a plate heat exchanger, and the cold accumulation device 594 preferably adopts a cold accumulation tank.

The connection structure of the chilled water cooling system will be described in detail below.

In the natural cooling loop, one end of a cooling tower 520 is connected in series with a chilled water main pump 5P1 through a pipeline and then is connected to one end of a heat exchanger 522 at the tail end of an air conditioner, the other end of the cooling tower is connected to one end of a high-temperature fluid side of a heat exchanger 593, the other end of the heat exchanger 522 at the tail end of the air conditioner is connected to one end of the heat exchanger, which is not connected with the cooling tower 520, through a pipeline, and the loop forms a main loop of the natural cooling loop. To provide overpressure protection for the cooling tower 520, piping on both sides of the cooling tower 520 is connected in parallel with a first pressure differential bypass branch 523.

In the mechanical cooling loop, two ends of an air-cooled chilled water main unit 521 are connected to two ends of one side of a heat exchanger 593 which is connected in series in the natural cooling loop through pipelines, and the chilled water auxiliary pump 5P2 and the cold accumulation device 594 are connected in series in the pipelines.

The chilled water cooling circuit has two working modes, namely a natural cooling mode and a partial natural cooling mode.

In the natural cooling mode, the primary chilled water pump 5P1 operates, and under the pressure provided by the primary chilled water pump 5P1, the chilled water absorbs heat in the heat exchanger 522 at the end of the air conditioner, and then returns to the other end of the heat exchanger 522 at the end of the air conditioner through the cooling tower 520 and the high-temperature fluid side of the heat exchanger 593. When the chilled water passes through the cooling tower 520, the heat of the chilled water is discharged to the outdoor environment through the cooling pipeline of the cooling tower 520, the temperature of the chilled water cooled by the cooling tower 520 is reduced to a proper temperature, heat exchange is not performed when the chilled water passes through the heat exchanger 593, and the chilled water returns to the heat exchanger 522 at the tail end of the air conditioner to be used as a refrigerant to take away the heat. In this operation mode, the mechanical cooling circuit does not perform auxiliary cooling, and the chilled water auxiliary pump 5P2 and the air-cooled chilled water main unit 521 do not operate.

In the partial natural cooling mode, the chilled water main pump 5P1 and the chilled water auxiliary pump 5P2 both work, the air-cooled chilled water main machine 521 works, and the chilled water returns to the other end of the heat exchanger 522 at the tail end of the air conditioner through the high-temperature fluid side of the cooling tower 520 and the heat exchanger 593 after absorbing heat by the heat exchanger 522 at the tail end of the air conditioner. In this mode, the chilled water is cooled by the cooling tower 520, and after the heat absorbed by the heat exchanger 522 at the air conditioner end is exhausted to the outdoor environment through the cooling pipeline of the cooling tower 520, the temperature is still higher than the temperature required by the heat exchanger 522 at the air conditioner end, the air-cooled chilled water main unit 521 operates, the chilled water auxiliary pump 5P2 operates, and the cooling liquid in the cold storage device 594 circulates in the mechanical cooling circuit under the driving of the chilled water auxiliary pump 5P 2. The chilled water passes through the heat exchanger 593, and after the heat of the chilled water is further absorbed by the cryogenic fluid on the other side of the heat exchanger 593, the temperature of the chilled water is reduced to the temperature required by the heat exchanger 522 at the air conditioning end. The heat can be taken away again as a refrigerant in the heat exchanger 522 at the air conditioning end. After the heat of the chilled water is absorbed by the heat exchanger 593, the cooling liquid of the mechanical cooling loop is sent to the air-cooled chilled water main unit 521 for cooling. In the mode, the mechanical cooling loop where the air cooling chilled water main engine is located assists cooling. The air-cooled chilled water main unit 521 operates.

In the technical scheme that this fifth embodiment provided, the refrigerated water cooling system not only can mainly adopt the cooling tower of natural cooling circuit, and the supplementary air-cooled refrigerator water host that adopts cools off, can also be in natural cooling circuit through the cooling tower cooling back, when the temperature is still too high and surpass the highest return water temperature that air-cooled refrigerated water host allowed, avoids the high pressure and high temperature warning of air-cooled refrigerated water host.

The natural cooler in the scheme of the invention has various choices, and can adopt a dry cooler and the like besides the closed cooling tower, the spray closed cooling tower, the heat exchanger and the plate heat exchanger in the embodiment. The end heat exchanger of the natural cooling circuit in series may be a heat exchanger of a liquid cooling server or another end heat exchanger, in addition to the heat exchanger at the air conditioning end in the above-described embodiment.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto, and variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

Claims (31)

1. A chilled water cooling system comprises a natural cooling loop formed by connecting a natural cooler, a chilled water main pump, a pipeline and a tail end heat exchanger in series, and a mechanical cooling loop formed by connecting a chilled water main machine, a chilled water auxiliary pump and a pipeline in series, wherein the tail end heat exchanger is arranged at a position needing to provide refrigeration.

2. The chilled water cooling system according to claim 1, wherein the controllably conductive-insulating device is a valve located on the mechanical cooling circuit.

3. The chilled water cooling system according to claim 1, wherein the controllably conductive-isolative device is a three-way mixing valve located at the junction of the mechanical cooling circuit and the natural cooling circuit.

4. The chilled water cooling system of claim 1, 2 or 3, wherein the chilled water main unit is a water-cooled chilled water main unit.

5. The chilled water cooling system of claim 4, wherein the free-cooling vessel is a dry chiller.

6. The chilled water cooling system according to claim 4, wherein the condensing side of the water-cooled chilled water main unit is cooled by a cooling tower.

7. The chilled water cooling system according to claim 6, wherein the cooling tower used on the condensing side of the water-cooled chilled water main unit is a closed cooling tower.

8. The chilled water cooling system of claim 6, wherein the free cooler is a cooling tower.

9. The chilled water cooling system according to claim 8, wherein the cooling tower as a free cooler is a closed cooling tower.

10. The chilled water cooling system according to claim 8, wherein the condensing side cooling tower is incorporated into a natural cooling circuit through a pipe, and a first valve (2V1) and a second valve (2V2) respectively provided at both ends of the condensing side cooling tower, and in case of natural cooling, the cooling tower on the condensing side of the water-cooled chilled water main unit can be used in series by controlling on/off states of the first valve and the second valve in addition to the cooling tower which mainly uses the natural cooling circuit.

11. The chilled water cooling system according to claim 10, wherein the first valve (2V1) and the second valve (2V2) are located at a connection of a natural cooling circuit and a mechanical cooling circuit.

12. The chilled water cooling system according to claim 4, wherein the condensation side of the water-cooled chilled water main unit adopts a heat exchanger using lake water/seawater or other cold water resources as a cooling medium.

13. The chilled water cooling system of claim 12, wherein the heat exchanger is a plate heat exchanger.

14. The chilled water cooling system of claim 12, wherein the free-cooling vessel is a heat exchanger with lake/seawater or other chilled water resources as a cooling medium.

15. The chilled water cooling system according to claim 14, wherein the heat exchanger as a free cooler is a plate heat exchanger.

16. The chilled water cooling system according to claim 14, wherein the high-temperature fluid inlet side of the heat exchanger with lake water/seawater or other cold water resources as cooling medium on the condensation side of the water-cooled chilled water main unit is merged into the natural cooling loop through a pipeline, a third valve (4V3) and a fourth valve (4V4) which are respectively positioned at the two ends of the high-temperature fluid inlet side of the heat exchanger on the condensation side of the water-cooled chilled water main unit, under the condition of natural cooling, except for the heat exchanger of the main natural cooling loop which takes lake water/seawater or other cold water resources as cooling media, the heat exchangers which are arranged on the condensation side of the water-cooled chilled water main unit and take lake water/seawater or other cold water resources as cooling media can be used in series by controlling the on/off states of a third valve (4V3) and a fourth valve (4V4) which are respectively arranged at the two ends of the high-temperature fluid access side of the heat exchanger on the condensation side of the water-cooled chilled water main unit.

17. The chilled water cooling system according to claim 16, wherein the third valve (4V3) and the fourth valve (4V4) at the two ends of the high-temperature fluid side of the water-cooled chilled water main unit condensation side heat exchanger are positioned at the joint of a natural cooling loop and a mechanical cooling loop

18. The chilled water cooling system of claim 1, 2 or 3, wherein the chilled water main unit is an air-cooled chilled water main unit.

19. The chilled water cooling system of claim 18, wherein the free cooler is a cooling tower.

20. The chilled water cooling system of claim 19, wherein the cooling tower is a closed cooling tower.

21. The chilled water cooling system of claim 18, wherein the free-cooling vessel is a heat exchanger with lake/seawater or other chilled water resources as a cooling medium.

22. The chilled water cooling system of claim 21, wherein the heat exchanger is a plate heat exchanger.

23. The chilled water cooling system of claim 18, wherein the free-cooling vessel is a dry chiller.

24. The chilled water cooling system according to claim 1, wherein the chilled water main unit is an air-cooled chilled water main unit, the controllable conduction-isolation device is a heat exchanger, two ends of one side of the heat exchanger are connected in series with a natural cooling loop, the cold accumulation device connected in series with the other side of the heat exchanger is connected with a water supply/return end of a mechanical cooling loop, and auxiliary cooling of the mechanical cooling loop can be controlled by starting the chilled water auxiliary pump.

25. The chilled water cooling system of claim 24, wherein the heat exchanger is a plate heat exchanger.

26. The chilled water cooling system of claim 24 or 25, wherein the free-cooling vessel is a cooling tower.

27. The chilled water cooling system of claim 26, wherein the free cooler is a closed cooling tower.

28. The chilled water cooling system according to claim 24 or 25, wherein the free-cooling vessel is a heat exchanger with lake/sea water or other cold water resources as a cooling medium.

29. The chilled water cooling system of claim 28, wherein the heat exchanger as a free cooler is a plate heat exchanger.

30. The chilled water cooling system of claim 24 or 25, wherein the free-cooling vessel is a dry chiller.

31. The chilled water cooling system of claim 1, wherein the terminal heat exchanger is a heat exchanger of an air conditioning terminal or a heat exchanger of a liquid cooling server.