A chiller

Abstract

The present invention discloses a chiller, comprising: a condenser; a liquid reservoir connected to an outlet of the condenser; an evaporator, wherein an inlet of the evaporator and an outlet of the liquid reservoir are connected via a refrigerant pipe; and a switch device provided on the refrigerant pipe for controlling the on-off of the refrigerant pipe, so as to shut off the refrigerant pipe when the chiller is shut down. By providing the switch device on the refrigerant pipe, the on-off of the refrigerant pipe is controlled by the switch device. When the chiller is operating normally, the switch device is opened to conduct the refrigerant pipe, so that the refrigerant in the liquid reservoir can flow through the refrigerant pipe to the evaporator for heat absorption and evaporation. When the chiller is shut down, the switch device is closed to shut off the refrigerant pipe, so that the refrigerant liquid in the liquid reservoir cannot enter the evaporator through the refrigerant pipe, thereby avoiding excessive liquid storage in the evaporator and preventing the compressor from returning liquid, causing overcurrent and other startup failures when the chiller is restarted.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and more particularly to a chiller. Background Art

[0002] like Figure 1 As shown, a conventional water-cooled chiller in the prior art comprises an evaporator 100, a compressor 200 connected to the outlet of the evaporator 100, a condenser 300 connected to the outlet of the compressor 200, and a throttling device 400 connected to the outlet of the condenser 300, wherein the throttling device 400 is connected to the inlet of the evaporator 100. In the prior art, the condenser 300 and the evaporator 100 are placed adjacent to each other, the refrigerant connecting pipe is relatively short, the refrigerant charge is relatively small, and the height difference between the condenser 300 and the evaporator 100 is not large. After the chiller is shut down, the condenser 300 and the evaporator 100 are equivalent to communicating vessels. Excessive liquid refrigerant in the evaporator 100 will not cause liquid backflow in the compressor 200 during subsequent startup.

[0003] However, for indirect evaporative condensing chillers, the refrigerant pipe between the condenser and evaporator is significantly longer, and a liquid reservoir is installed at a higher position than the evaporator. During winter operation, taking advantage of the low ambient temperature, the refrigerant gas releases heat and condenses in the condenser. The refrigerant liquid flows along the pipes into the liquid reservoir, and under the action of gravity or the push of the downstream refrigerant pump, it enters the evaporator shell and tube, absorbs the heat of the chilled water, evaporates, and then flows back along the gas pipe to the condenser to participate in condensation. This solution can fully utilize the natural cooling potential of the low winter temperature environment and reduce the system's year-round operating energy consumption. The longer refrigerant pipe and the installation of the liquid reservoir increase the chiller's filling volume. Moreover, the condenser and liquid reservoir are located higher than the evaporator. After the chiller is shut down, a large amount of refrigerant liquid will enter the evaporator shell and tube under the action of gravity, resulting in excessive liquid storage in the evaporator. When the compressor is subsequently restarted, it will cause liquid backflow and overcurrent, resulting in startup failure.

[0004] In summary, how to avoid excessive liquid storage in the evaporator, which may lead to liquid backflow or startup failure in the compressor, is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, an object of the present invention is to provide a chiller that can avoid the situation where excessive liquid in the evaporator causes liquid backflow or startup failure in the compressor.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A chiller comprising:

[0008] condenser;

[0009] a liquid reservoir connected to an outlet of the condenser;

[0010] an evaporator, wherein an inlet of the evaporator is connected to an outlet of the liquid accumulator via a refrigerant pipe;

[0011] The switch device is provided in the refrigerant pipeline and is used to control the on-off of the refrigerant pipeline so as to shut down the refrigerant pipeline when the chiller is shut down.

[0012] Optionally, the switching device is an electric valve, and the electric valve is connected to a PLC controller of the chiller so as to be controlled to open or close the electric valve by the PLC controller.

[0013] Optionally, the PLC controller and the electric valve are both connected to a UPS uninterruptible power supply.

[0014] Optionally, the switching device is an electronic expansion valve, and the electronic expansion valve is connected to a PLC controller of the chiller so as to control the opening or closing of the electronic expansion valve through the PLC controller.

[0015] Optionally, the PLC controller and the electronic expansion valve are both connected to a UPS uninterruptible power supply.

[0016] Optionally, the refrigerant pipeline includes:

[0017] a first refrigerant pipe connected to the outlet of the liquid accumulator;

[0018] a second refrigerant pipe connected to the inlet of the evaporator;

[0019] a third refrigerant pipe, connected between the first refrigerant pipe and the second refrigerant pipe, and provided with a refrigerant pump;

[0020] The fourth refrigerant pipe is connected between the first refrigerant pipe and the second refrigerant pipe, is arranged in parallel with the third refrigerant pipe, and is provided with a one-way valve.

[0021] Optionally, the switch device is provided on the first refrigerant pipe, and the second refrigerant pipe is provided with a throttling device.

[0022] Optionally, the switching device is provided on the second refrigerant pipe.

[0023] The chiller provided by the present invention provides a switching device on the refrigerant pipeline between the evaporator and the liquid reservoir, and uses the switching device to control the on and off of the refrigerant pipeline. It can be understood that when the chiller is operating normally, the switching device is opened to make the refrigerant pipeline conductive, so that the refrigerant in the liquid reservoir can flow to the evaporator through the refrigerant pipeline to absorb heat and evaporate; when the chiller is shut down, the switching device is closed to cut off the refrigerant pipeline. At this time, the refrigerant liquid in the liquid reservoir cannot enter the evaporator through the refrigerant pipeline, avoiding excessive liquid storage in the evaporator, thereby preventing the compressor from returning liquid, causing overcurrent and other startup failures when the chiller compressor is restarted subsequently. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 It is a structural diagram of a traditional water-cooled chiller in the prior art;

[0026] Figure 2 A schematic structural diagram of a water chiller provided in a specific embodiment of the present invention;

[0027] Figure 3 This is a structural schematic diagram of a chiller provided in another specific embodiment of the present invention.

[0028] Figure 1 The accompanying drawings are:

[0029] 100 is the evaporator, 200 is the compressor, 300 is the condenser, and 400 is the throttling device;

[0030] Figure 2 and 3 The accompanying drawings are:

[0031] 1 is a condenser, 2 is a liquid accumulator, 3 is an evaporator, 4 is a switch device, 51 is a first refrigerant pipe, 52 is a second refrigerant pipe, 53 is a third refrigerant pipe, 54 is a fourth refrigerant pipe, 6 is a refrigerant pump, 7 is a one-way valve, 8 is a throttling device, and 9 is a compressor. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] The core of the present invention is to provide a chiller that can avoid the situation where excessive liquid storage in the evaporator causes liquid backflow or startup failure in the compressor.

[0034] Please refer to Figure 2 and Figure 3 , Figure 2 A schematic structural diagram of a water chiller provided in a specific embodiment of the present invention; Figure 3 This is a structural schematic diagram of a chiller provided in another specific embodiment of the present invention.

[0035] An embodiment of the present invention provides a chiller, comprising a condenser 1, a liquid reservoir 2, an evaporator 3 and a switch device 4; the liquid reservoir 2 is connected to the outlet of the condenser 1; the inlet of the evaporator 3 and the outlet of the liquid reservoir 2 are connected via a refrigerant pipe; the switch device 4 is provided in the refrigerant pipe, and the switch device 4 is used to control the on and off of the refrigerant pipe so as to shut down the refrigerant pipe when the chiller is shut down.

[0036] That is to say, this embodiment sets a switch device 4 on the refrigerant pipeline between the evaporator 3 and the liquid reservoir 2, and uses the switch device 4 to control the on and off of the refrigerant pipeline. It can be understood that when the chiller is operating normally, the switch device 4 is opened to make the refrigerant pipeline conductive, so that the refrigerant in the liquid reservoir 2 can flow to the evaporator 3 through the refrigerant pipeline for heat absorption and evaporation; when the chiller is shut down, the switch device 4 is closed to cut off the refrigerant pipeline. At this time, the refrigerant liquid in the liquid reservoir 2 cannot enter the evaporator 3 through the refrigerant pipeline, avoiding excessive liquid storage in the evaporator 3, thereby preventing the subsequent restart of the compressor 9 of the chiller from causing liquid backflow in the compressor 9, causing overcurrent and other startup failures.

[0037] It should be noted that this embodiment does not limit the specific structure of the switch device 4, as long as the refrigerant pipeline can be controlled to be on and off by operating the switch device 4. The switch device 4 can be manual, electric, pneumatic or hydraulic.

[0038] To facilitate control of switch device 4, in some embodiments, switch device 4 is a motorized valve connected to the chiller's PLC controller, allowing the PLC controller to control its opening or closing. In other words, in this embodiment, the PLC controller controls the opening or closing of the motorized valve, thereby opening or closing the refrigerant pipeline. This provides convenient control and ease of implementation. For example, when the chiller shuts down, the PLC controller programmatically closes the motorized valve.

[0039] Furthermore, in some embodiments, the PLC controller and the electric valve are both connected to a UPS (uninterruptible power supply) to ensure that the switch device 4 can be closed promptly in the event of a utility power outage, thereby preventing a large amount of refrigerant liquid from flowing into the evaporator 3. That is, in this embodiment, the PLC controller and the electric valve are both powered by a UPS (uninterruptible power supply). Thus, in the event of a utility power outage, the PLC controller can still close the electric valve, preventing a large amount of refrigerant liquid from flowing into the evaporator 3 through the refrigerant pipe.

[0040] Considering another implementation of switch device 4, in some embodiments, switch device 4 is an electronic expansion valve connected to the chiller's PLC controller, so that the PLC controller can control the opening or closing of the electronic expansion valve. In other words, in this embodiment, the PLC controller controls the opening or closing of the electronic expansion valve, thereby connecting or disconnecting the refrigerant pipeline. This provides convenient control and ease of implementation. For example, when the chiller is shut down, the PLC controller closes the electronic expansion valve through a program.

[0041] Furthermore, in some embodiments, the PLC controller and the electronic expansion valve are both connected to a UPS (uninterruptible power supply) to ensure that the switch device 4 can be closed promptly in the event of a utility power outage, thereby preventing a large amount of refrigerant liquid from flowing into the evaporator 3. That is, in this embodiment, the PLC controller and the electronic expansion valve are both powered by a UPS (uninterruptible power supply). Thus, in the event of a utility power outage, the PLC controller can still close the electronic expansion valve, preventing a large amount of refrigerant liquid from flowing into the evaporator 3 through the refrigerant pipe.

[0042] In addition, it should be noted that the above embodiment does not limit the specific arrangement of the refrigerant pipeline, as long as it can connect the liquid receiver 2 and the evaporator 3.

[0043] In some embodiments, the refrigerant pipe includes a first refrigerant pipe 51, a second refrigerant pipe 52, a third refrigerant pipe 53 and a fourth refrigerant pipe 54, the first refrigerant pipe 51 is connected to the outlet of the liquid accumulator 2; the second refrigerant pipe 52 is connected to the inlet of the evaporator 3; the third refrigerant pipe 53 and the fourth refrigerant pipe 54 are arranged in parallel, and the third refrigerant pipe 53 and the fourth refrigerant pipe 54 are respectively connected between the first refrigerant pipe 51 and the second refrigerant pipe 52, the third refrigerant pipe 53 is provided with a refrigerant pump 6; the fourth refrigerant pipe 54 is provided with a one-way valve 7. It can be understood that the outlet end of the one-way valve 7 is connected to the second refrigerant pipe 52.

[0044] Furthermore, this embodiment does not limit the specific location of the switch device 4. Figure 3 As shown, in some embodiments, the switch device 4 is disposed in the first refrigerant pipe 51. That is, the switch device 4 is disposed near the outlet of the liquid reservoir 2, before the inlet of the refrigerant pump 6 and the one-way valve 7. This allows the refrigerant liquid in the liquid reservoir 2 to flow to the evaporator 3 to be promptly blocked, resulting in a relatively low amount of refrigerant liquid in the refrigerant pipe when the chiller is shut down. When the chiller is started, the switch device 4 opens, allowing the refrigerant in the liquid reservoir 2 to flow smoothly into the evaporator 3. When the chiller is shut down, the switch device 4 closes, preventing the refrigerant liquid in the liquid reservoir 2 from flowing into the evaporator 3 after the chiller is shut down.

[0045] It should be noted that, based on this embodiment, a throttling device 8 may be provided in the second refrigerant pipe 52 .

[0046] like Figure 2 As shown, in other embodiments, the switch device 4 is provided in the second refrigerant pipe 52. That is, the switch device 4 is provided near the inlet of the evaporator 3 and is located after the outlets of the refrigerant pump 6 and the one-way valve 7.

[0047] Furthermore, in some embodiments, the switch device 4 is an electronic expansion valve. It should be noted that when the switch device 4 is provided in the second refrigerant pipe 52, the switch device 4 and the throttling device 8 can be combined into one, that is, the switch device 4 is used instead of the throttling device 8. At this time, the switch device 4 not only controls the on-off of the second refrigerant pipe 52, but also has a throttling effect. For conventional chillers in the prior art, due to the large cooling capacity of the entire unit, the throttling device 8 provided in the second refrigerant pipe 52 generally adopts a throttling orifice plate, a thermal expansion valve or a float valve; after the switch device 4 and the throttling device 8 are combined into one, in order to achieve the liquid isolation effect after shutdown, this embodiment adopts an electronic expansion valve. In this way, not only can the adjustment accuracy of the partial load condition be achieved, but also the electronic expansion valve can be fully closed after shutdown.

[0048] It should be noted that placing the switch device 4 in the second refrigerant pipe 52 requires a large-capacity electronic expansion valve, which is relatively expensive. Furthermore, frequent adjustments based on load changes shorten the lifespan of the electronic expansion valve. Therefore, compared to placing the switch device 4 in the second refrigerant pipe 52, placing the switch device 4 in the first refrigerant pipe 51 can save costs and extend the lifespan of the electronic expansion valve.

[0049] It should also be noted that, in this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0050] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0051] The above is a detailed introduction to the chiller provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the method and core ideas of the present invention. It should be pointed out that, for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications may be made to the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A chiller, characterized in that: include: Condenser (1); A liquid reservoir (2) connected to the outlet of the condenser (1); an evaporator (3), wherein an inlet of the evaporator (3) is connected to an outlet of the liquid accumulator (2) via a refrigerant pipe, and the position of the liquid accumulator (2) is higher than that of the evaporator (3); The refrigerant pipeline comprises: a first refrigerant pipeline (51), connected to the outlet of the liquid accumulator (2); a second refrigerant pipeline (52), connected to the inlet of the evaporator (3); a third refrigerant pipeline (53), connected between the first refrigerant pipeline (51) and the second refrigerant pipeline (52), and provided with a refrigerant pump (6); a fourth refrigerant pipeline (54), connected between the first refrigerant pipeline (51) and the second refrigerant pipeline (52), and arranged in parallel with the third refrigerant pipeline (53), and provided with a one-way valve (7); A switch device (4) is provided on the refrigerant pipeline and is used to control the on / off of the refrigerant pipeline so as to shut off the refrigerant pipeline when the chiller is shut down; The PLC controller is used to control the switch device (4) to open when the chiller is operating normally, so that the refrigerant pipeline is connected; and to control the switch device (4) to close when the chiller is shut down, so that the refrigerant pipeline is shut off, so that the refrigerant liquid in the liquid accumulator (2) cannot enter the evaporator (3) through the refrigerant pipeline.

2. The chiller according to claim 1, characterized in that: The switch device (4) is an electric valve, and the electric valve is connected to the PLC controller so as to control the opening or closing of the electric valve through the PLC controller.

3. The chiller according to claim 2, characterized in that: The PLC controller and the electric valve are both connected to a UPS uninterruptible power supply.

4. The chiller according to claim 1, characterized in that: The switch device (4) is an electronic expansion valve, and the electronic expansion valve is connected to the PLC controller so that the electronic expansion valve can be controlled to open or close by the PLC controller.

5. The chiller according to claim 4, characterized in that: The PLC controller and the electronic expansion valve are both connected to a UPS uninterruptible power supply.

6. The chiller according to any one of claims 1 to 5, characterized in that: The switch device (4) is provided on the first refrigerant pipe (51), and the second refrigerant pipe (52) is provided with a throttling device (8).

7. The chiller according to any one of claims 1 to 5, characterized in that: The switch device (4) is provided on the second refrigerant pipe (52).

8. A chiller control method, characterized in that: Applied to the chiller according to any one of claims 1 to 7, the chiller control method comprises: When the chiller is operating normally, the switch device (4) is controlled to be open, so that the refrigerant pipeline is connected; when the chiller is shut down, the switch device (4) is controlled to be closed, so that the refrigerant pipeline is cut off, so that the refrigerant liquid in the liquid storage device (2) cannot enter the evaporator (3) through the refrigerant pipeline.

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