Winter self-adaptive anti-freezing system and method for water chilling unit

Abstract

The invention discloses a self-adaptive anti-freezing system and method for a water chilling unit in winter, and an evaporator anti-freezing emptying subsystem of the self-adaptive anti-freezing system for the water chilling unit in winter is used for judging whether the evaporator has the freezing pipe freezing risk or not according to the environment temperature, the chilled water flow of the evaporator and the circulating water flow; if yes, gas in the water tank is pumped into the gas storage tank to reduce the pressure in the water tank, and chilled water of the evaporator is completely discharged into the water tank through the pressure difference; the water tank anti-freezing protection subsystem is used for judging whether water tank anti-freezing protection is needed or not according to the temperature and the liquid level in the water tank, and if yes, the water tank is heated; the chilled water backflow subsystem is used for judging whether chilled water circulation can be normally recovered and pressure reduction in the water tank is stopped or not, if yes, the high-pressure gas in the gas storage tank is discharged into the water tank to increase the pressure in the water tank, and chilled water in the water tank is discharged back to the chilled water inlet pipeline through the pressure difference. Precise discharging and backflow of chilled water are achieved, and accumulation of the chilled water is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of chillers, and in particular to a winter self-adaptive antifreeze system and method for chillers. Background Art

[0002] In data centers and industrial plants, where evaporative chillers are used for cooling, a primary unit and a backup unit are often deployed to ensure year-round, uninterrupted cooling. In this scenario, the backup unit's evaporator must maintain sufficient chilled water so that if the primary unit fails, the backup unit can be immediately activated to ensure a consistent chilled water supply for the data center and industrial plant.

[0003] However, in winter, if the standby machine's chilled water pump stops running due to a malfunction, the pipeline is blocked, or the standby machine fails and no one drains the evaporator for a long time, the chilled water flow will be cut off, making it impossible for the standby machine to start normally, resulting in a lot of chilled water accumulating in the evaporator pipeline, which in turn causes the evaporator heat exchange tube to freeze and crack, water leakage in the refrigeration system, etc., affecting the chilled water supply. In severe cases, the entire system will be damaged, increasing the equipment use and operation and maintenance costs. Summary of the Invention

[0004] In order to solve the deficiencies in the existing technology, the problem that the chilled water system of the chiller cannot work in winter, or the unit fails and no one drains the evaporator for a long time, resulting in freezing and cracking of the evaporator heat exchange tubes, is solved.

[0005] The present invention provides a self-adaptive antifreeze system and method for a chiller in winter.

[0006] The present invention adopts the following technical solutions.

[0007] A first aspect of the present invention discloses a winter adaptive antifreeze system for a chiller unit, wherein the evaporator of the unit includes a chilled water outlet pipe and a chilled water inlet pipe for chilled water circulation, and the drain outlet of the evaporator is connected to the water inlet of a water tank, and the water outlet of the water tank is connected to the chilled water inlet pipe; the water tank is also connected to a gas storage tank, and the system is characterized in that it includes:

[0008] The evaporator antifreeze and emptying subsystem is used to determine whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate of the evaporator, and the circulating water volume. If there is a risk of frozen pipes, the gas in the water tank is pumped into the gas storage tank to reduce the pressure in the water tank, stop the circulation of chilled water, and use the pressure difference between the evaporator and the water tank to completely drain the chilled water from the evaporator into the water tank;

[0009] The water tank antifreeze protection subsystem is used to determine whether the water tank antifreeze protection is needed based on the temperature and liquid level in the water tank. If necessary, the water tank is heated;

[0010] The chilled water return subsystem is used to determine whether the chilled water circulation can be restored normally and the pressure reduction in the water tank has stopped. If so, the high-pressure gas in the gas storage tank is discharged into the water tank to increase the pressure in the water tank. The chilled water in the water tank is discharged back into the chilled water inlet pipe by using the pressure difference between the water tank and the chilled water inlet pipe.

[0011] Preferably, judging whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate and the circulating water volume of the evaporator includes:

[0012] If the following conditions are met simultaneously: ambient temperature ≤ ambient low temperature alarm value, evaporator chilled water flow ≤ chilled water cutoff alarm value, and evaporator flow volume ≥ chilled water low level, and the chilled water cutoff duration lasts for the set duration, the evaporator is judged to have a risk of frozen pipes.

[0013] Preferably, the evaporator antifreeze and emptying subsystem includes an ambient thermometer, a chilled water flow meter and a heat exchange tube level meter; wherein, the ambient thermometer is used to detect the ambient temperature; the chilled water flow meter is installed on the chilled water outlet pipe of the evaporator, and is used to detect the chilled water flow of the evaporator; the heat exchange tube level meter is installed on the heat exchange tube of the evaporator, and is used to detect the circulating water volume of the evaporator.

[0014] Preferably, the evaporator antifreeze and emptying subsystem includes an electric exhaust valve, a vacuum pump, a one-way valve and a water tank pressure sensor installed on the water tank;

[0015] The electric exhaust valve, vacuum pump and one-way valve are connected in sequence between the air outlet of the water tank and the air inlet of the gas storage tank, and are opened when there is a risk of freezing pipes in the evaporator to extract the gas in the water tank into the gas storage tank to reduce the pressure in the water tank. They are closed after the vacuum pump is turned on for the set vacuum pump evacuation time or when the water tank pressure detected by the water tank pressure sensor is ≤ the vacuum pump closing pressure.

[0016] Preferably, the evaporator antifreeze drain subsystem includes a chilled water outlet electric valve installed on the chilled water outlet pipe of the evaporator, a chilled water inlet electric valve installed on the chilled water inlet pipe, and a drain electric valve installed on the connection channel between the evaporator drain port and the water tank inlet port;

[0017] After the pressure in the water tank is reduced, the chilled water outlet electric valve and the chilled water inlet electric valve are closed to stop the chilled water circulation, and the drain electric valve is opened to utilize the pressure difference between the shell and tube evaporator and the water tank to completely discharge the chilled water of the shell and tube evaporator into the water tank. Then the chilled water outlet electric valve and the chilled water inlet electric valve are opened, and the drain electric valve is closed.

[0018] Preferably, the evaporator antifreeze emptying subsystem includes a water tank level gauge, which is connected to the water tank and is used to detect the water tank liquid level to calculate the liquid level growth rate and determine whether the chilled water of the evaporator has been completely discharged into the water tank. The specific criterion is: if the liquid level growth rate ≤ the water tank liquid level growth rate setting value, it is determined that the chilled water of the evaporator has been completely discharged into the water tank.

[0019] Preferably, the water tank antifreeze protection subsystem includes a chilled water pump, a water tank temperature sensor and a water tank electric heater; wherein the chilled water pump is installed on the chilled water inlet pipe; the water tank temperature sensor is installed in the water tank for detecting the temperature in the water tank;

[0020] The water tank electric heating element is arranged inside the water tank, and is turned on when the water tank antifreeze protection is required to heat the water tank, and is turned off after the water tank electric heating element is turned on for a preset water tank heating time or when the temperature inside the water tank is ≥ the water tank stop heating temperature value; the criterion for the need for water tank antifreeze protection is: the freezing water pump is turned on, the temperature inside the water tank is ≤ the water tank low temperature alarm value, and the water tank liquid level is ≥ the water tank heating liquid level setting value.

[0021] Preferably, the determining whether the chilled water cycle can be restored normally includes:

[0022] If the chilled water pump on the chilled water inlet pipe is detected to be turned on from off and the chilled water flow rate is greater than the chilled water flow interruption alarm value, it is determined that the chilled water circulation in the evaporator chilled water outlet and inlet pipes can be restored normally.

[0023] Preferably, the chilled water return subsystem includes an exhaust electric valve, an air storage tank pressure sensor, and a water tank water outlet electric valve; the exhaust electric valve is connected between the air inlet of the water tank and the air outlet of the air storage tank; the air storage tank pressure sensor is installed on the air storage tank to detect the air storage tank pressure; the water tank water outlet electric valve is provided on the connection path between the water tank outlet and the chilled water inlet pipe;

[0024] The exhaust electric valve opens when the chilled water circulation can be restored normally and the pressure reduction in the water tank has stopped, so as to discharge the high-pressure gas in the gas storage tank into the water tank and increase the pressure in the water tank until the pressure in the gas storage tank is equal to the pressure in the water tank. At this time, the water tank water outlet electric valve opens to utilize the pressure difference between the water tank and the chilled water inlet pipe and the chilled water pump on the chilled water inlet pipe to discharge the chilled water in the water tank back into the chilled water inlet pipe until the water tank liquid level is ≤ the water tank emptying level setting value.

[0025] A second aspect of the present invention discloses a method for adaptively preventing freezing of a chiller in winter, which is implemented based on the system described above and includes:

[0026] Determine whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate of the evaporator, and the circulating water volume. If there is a risk of frozen pipes in the evaporator, pump the gas in the water tank into the gas storage tank to reduce the pressure in the water tank, stop the chilled water circulation, and use the pressure difference between the evaporator and the water tank to completely drain the chilled water from the evaporator into the water tank.

[0027] Determine whether the water tank needs antifreeze protection based on the water tank temperature and liquid level. If necessary, heat the water tank;

[0028] Determine whether the chilled water circulation can be restored normally and the pressure drop in the water tank has stopped. If so, discharge the high-pressure gas in the gas storage tank into the water tank to increase the pressure in the water tank, and use the pressure difference between the water tank and the chilled water inlet pipe to discharge the chilled water in the water tank back to the chilled water inlet pipe.

[0029] A third aspect of the present invention discloses a chiller, comprising the aforementioned winter adaptive antifreeze system for the chiller.

[0030] A fourth aspect of the present invention discloses an air conditioner, comprising the aforementioned chiller.

[0031] A fifth aspect of the present invention discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and is characterized in that when the computer program is executed by a processor, the method described is implemented.

[0032] The beneficial effect of the present invention is that, compared with the prior art,

[0033] The present invention uses the evaporator antifreeze and emptying subsystem to monitor multiple data based on ambient temperature, evaporator chilled water flow rate, and circulating water volume, to accurately determine the risk of evaporator pipe freezing. By pumping gas from the water tank into the gas storage tank to reduce the pressure in the water tank, the pressure difference between the evaporator and the water tank is used to quickly discharge the evaporator's chilled water into the water tank, preventing the evaporator heat exchange tube from freezing and cracking in winter and water leakage in the refrigeration system, thereby improving the safety and reliability of evaporator use.

[0034] The present invention uses a water tank antifreeze protection subsystem to monitor multiple data such as the temperature and liquid level in the water tank, accurately determine whether water tank antifreeze protection is needed, and prevent the water tank from freezing under long-term low temperatures by heating the water tank, thereby improving the reliability and safety of system operation.

[0035] The present invention uses a chilled water reflux subsystem to discharge the high-pressure gas in the gas storage tank into the water tank to increase the pressure in the water tank, and utilizes the pressure difference between the water tank and the chilled water inlet pipe to discharge the chilled water in the water tank back into the chilled water inlet pipe, thereby achieving rapid circulation of chilled water and improving operating efficiency and water resource utilization.

[0036] The present invention drives the emptying and circulation of chilled water through pressure difference, thereby reducing the risk of failure and improving equipment durability. At the same time, it automatically empties the return chilled water according to multiple data, thereby improving energy utilization and operating efficiency and avoiding waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a structural diagram of a winter adaptive antifreeze control system for a chiller according to the present invention;

[0038] In the figure: 1-shell and tube evaporator, 2-first drain electric valve, 3-second drain electric valve, 4-chilled water outlet electric valve, 5-chilled water flow meter, 6-chilled water inlet electric valve, 7-ambient thermometer, 8-chilled water pump, 9-gas tank pressure sensor, 10-safety valve, 11-gas tank, 12-exhaust electric valve, 13-water tank pressure sensor, 14-water tank level gauge, 15-water tank, 16-water tank temperature sensor, 17-water tank electric heating element, 18-exhaust electric valve, 19-vacuum pump, 20-check valve, 21-water tank outlet electric valve, 22-heat exchange tube level gauge. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without making creative efforts are all within the scope of protection of the present invention.

[0040] like Figure 1 As shown, embodiment 1 of the present invention provides a winter adaptive antifreeze system for a chiller. The evaporator of the chiller includes a chilled water outlet pipe and a chilled water inlet pipe for chilled water circulation. The drain port of the evaporator is connected to the water inlet of a water tank 15, and the water outlet of the water tank 15 is connected to the chilled water inlet pipe. The water tank 15 is also connected to an air storage tank 11. The system includes:

[0041] The evaporator antifreeze and emptying subsystem is used to determine whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate of the evaporator, and the circulating water volume. If there is a risk of frozen pipes, the gas in the water tank 15 is pumped into the gas storage tank 11 to reduce the pressure in the water tank 15, stop the circulation of chilled water, and use the pressure difference between the evaporator and the water tank 15 to completely drain the chilled water from the evaporator into the water tank 15;

[0042] The water tank antifreeze protection subsystem is used to determine whether the water tank antifreeze protection is needed based on the temperature and liquid level in the water tank 15, and if necessary, heat the water tank 15;

[0043] The chilled water return subsystem is used to determine whether the chilled water circulation can be restored normally and the pressure reduction in the water tank 15 has stopped. If so, the high-pressure gas in the gas storage tank 11 is discharged to the water tank 15 to increase the pressure in the water tank 15, and the chilled water in the water tank 15 is discharged back to the chilled water inlet pipe by using the pressure difference between the water tank 15 and the chilled water inlet pipe.

[0044] The determination of whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate, and the circulating water volume of the evaporator includes:

[0045] If the following conditions are met simultaneously: ambient temperature ≤ ambient low temperature alarm value, evaporator chilled water flow ≤ chilled water cutoff alarm value, and evaporator flow volume ≥ chilled water low level, and the chilled water cutoff duration lasts for the set duration, the evaporator is judged to have a risk of frozen pipes.

[0046] The evaporator antifreeze and emptying subsystem includes an ambient thermometer 7, a chilled water flowmeter 5 and a heat exchange tube level meter 22; wherein, the ambient thermometer 7 is used to detect the ambient temperature; the chilled water flowmeter 5 is installed on the chilled water outlet pipe of the evaporator, and is used to detect the chilled water flow of the evaporator; the heat exchange tube level meter 22 is installed on the heat exchange tube of the evaporator, and is used to detect the circulating water volume of the evaporator.

[0047] The evaporator antifreeze and emptying subsystem includes an electric exhaust valve 18, a vacuum pump 19, a one-way valve 20, and a water tank pressure sensor 13 installed on the water tank 15;

[0048] The exhaust electric valve 18, vacuum pump 19, and one-way valve 20 are connected in sequence between the air outlet of the water tank 15 and the air inlet of the gas storage tank 11, and are opened when there is a risk of freezing the pipes in the evaporator to extract the gas in the water tank 15 into the gas storage tank 11, reducing the pressure in the water tank 15, and are closed after the vacuum pump 19 is turned on for the set vacuum pump evacuation time or when the water tank pressure detected by the water tank pressure sensor 13 is ≤ the vacuum pump closing pressure.

[0049] The one-way valve 20 allows gas to flow only from the water tank 15 to the gas storage tank 11 .

[0050] The evaporator antifreeze drain subsystem includes a chilled water outlet electric valve 4 installed on the chilled water outlet pipe of the evaporator, a chilled water inlet electric valve 6 installed on the chilled water inlet pipe, and a drain electric valve installed on the connection channel between the evaporator drain port and the water tank inlet;

[0051] The water tank 15 and the shell and tube evaporator 1 are connected via a first drain electric valve 2 , and the first drain electric valve 2 and the water tank 15 are further connected to the shell and tube evaporator 1 via a pipeline provided with a second drain electric valve 3 .

[0052] After the pressure in the water tank 15 is reduced, the chilled water outlet electric valve 4 and the chilled water inlet electric valve 6 are closed to stop the chilled water circulation, and multiple drain electric valves are opened to utilize the pressure difference between the shell and tube evaporator 1 and the water tank 15 to completely discharge the chilled water in the shell and tube evaporator 1 to the water tank 15. Then the chilled water outlet electric valve 4 and the chilled water inlet electric valve 6 are opened, and all drain electric valves are closed.

[0053] The evaporator antifreeze emptying subsystem includes a water tank level gauge 14, which is connected to the water tank 15 and is used to detect the water tank liquid level to calculate the liquid level growth rate and determine whether the evaporator's chilled water has been completely discharged into the water tank 15. The specific judgment criterion is: if the liquid level growth rate ≤ the water tank liquid level growth rate setting value, it is determined that the evaporator's chilled water has been completely discharged into the water tank.

[0054] Preferably, the water tank level gauge 14 is arranged outside the water tank 15 to avoid damage to the water tank level gauge 14 during the heating process.

[0055] The water tank antifreeze protection subsystem includes a chilled water pump 8, a water tank temperature sensor 16 and a water tank electric heater 17; wherein the chilled water pump 8 is installed on the chilled water inlet pipe; the water tank temperature sensor 16 is installed in the water tank 15 for detecting the temperature in the water tank;

[0056] The water tank electric heater 17 is arranged inside the water tank 15, and is turned on when water tank antifreeze protection is required to heat the water tank 15, and is turned off after the water tank electric heater 17 is turned on for a preset water tank heating time or when the temperature inside the water tank is ≥ the water tank stop heating temperature value; the criterion for water tank antifreeze protection is: the chilled water pump 8 is turned on, the temperature inside the water tank is ≤ the water tank low temperature alarm value, and the water tank liquid level is ≥ the water tank heating liquid level setting value.

[0057] The determining whether the chilled water cycle can be restored normally includes:

[0058] If it is detected that the chilled water pump 8 on the chilled water inlet pipeline is turned from off to on and the chilled water flow rate is greater than the chilled water flow interruption alarm value, it is determined that the chilled water circulation of the evaporator chilled water outlet and water inlet pipeline can be restored normally.

[0059] Preferably, when determining whether there is a risk of freezing pipes in the evaporator, the chilled water pump 8 is in a normally closed state, and the chilled water pump 8 can be turned on and off by manual control or by a host computer.

[0060] The chilled water return subsystem includes an exhaust electric valve 12, an air tank pressure sensor 9, and a water tank water outlet electric valve 21; the exhaust electric valve 12 is connected between the air inlet of the water tank 15 and the air outlet of the air tank 11; the air tank pressure sensor 9 is installed on the air tank 11 to detect the air tank pressure; the water tank water outlet electric valve 21 is set in the connection path between the water outlet of the water tank 15 and the chilled water inlet pipe;

[0061] The exhaust electric valve 21 opens when the chilled water circulation can be restored normally and the pressure reduction in the water tank 15 has stopped, so as to discharge the high-pressure gas in the gas storage tank 11 to the water tank 15, increase the pressure in the water tank 15, until the gas storage tank pressure is equal to the water tank pressure, at this time the water tank water outlet electric valve 21 opens, and uses the pressure difference between the water tank 15 and the chilled water inlet pipe and the chilled water pump 8 on the chilled water inlet pipe to discharge the chilled water in the water tank 15 back to the chilled water inlet pipe, until the water tank liquid level ≤ the water tank emptying level setting value, and then the exhaust electric valve and the water tank water outlet electric valve are closed.

[0062] Preferably, a safety valve 10 is provided on the gas storage tank 11 to ensure safe operation of the gas storage tank 11 .

[0063] Embodiment 2 of the present invention provides a method for adaptively preventing freezing of a chiller in winter, which is implemented based on the aforementioned system and is characterized in that the method includes:

[0064] Based on the ambient temperature, the chilled water flow rate of the evaporator, and the circulating water volume, determine whether there is a risk of frozen pipes in the evaporator. If there is a risk, the gas in the water tank 15 is pumped into the gas storage tank 11 to reduce the pressure in the water tank 15, stop the chilled water circulation, and use the pressure difference between the evaporator and the water tank 15 to completely discharge the chilled water in the evaporator into the water tank 15;

[0065] Determine whether water tank antifreeze protection is needed based on the water tank temperature and liquid level. If necessary, heat the water tank 15.

[0066] Determine whether the chilled water circulation can be restored normally and the pressure reduction in the water tank 15 has stopped. If so, discharge the high-pressure gas in the gas storage tank 11 to the water tank 15 to increase the pressure in the water tank 15, and use the pressure difference between the water tank 15 and the chilled water inlet pipe to discharge the chilled water in the water tank 15 back to the chilled water inlet pipe.

[0067] Embodiment 3 of the present invention provides a chiller, including the aforementioned winter adaptive antifreeze system for the chiller.

[0068] Embodiment 4 of the present invention provides an air conditioner, comprising the aforementioned chiller.

[0069] Embodiment 5 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described above is implemented.

[0070] The beneficial effect of the present invention is that, compared with the prior art,

[0071] The present invention uses the evaporator antifreeze and emptying subsystem to monitor multiple data based on ambient temperature, evaporator chilled water flow rate, and circulating water volume, to accurately determine the risk of evaporator pipe freezing. By pumping gas from the water tank into the gas storage tank to reduce the pressure in the water tank, the pressure difference between the evaporator and the water tank is used to quickly discharge the evaporator's chilled water into the water tank, preventing the evaporator heat exchange tube from freezing and cracking in winter and water leakage in the refrigeration system, thereby improving the safety and reliability of evaporator use.

[0072] The present invention uses a water tank antifreeze protection subsystem to monitor multiple data such as the temperature and liquid level in the water tank, accurately determine whether water tank antifreeze protection is needed, and prevent the water tank from freezing under long-term low temperatures by heating the water tank, thereby improving the reliability and safety of system operation.

[0073] The present invention uses a chilled water reflux subsystem to discharge the high-pressure gas in the gas storage tank into the water tank to increase the pressure in the water tank, and utilizes the pressure difference between the water tank and the chilled water inlet pipe to discharge the chilled water in the water tank back into the chilled water inlet pipe, thereby achieving rapid circulation of chilled water and improving operating efficiency and water resource utilization.

[0074] The present invention drives the emptying and circulation of chilled water through pressure difference, thereby reducing the risk of failure and improving equipment durability. At the same time, it automatically empties the return chilled water according to multiple data, thereby improving energy utilization and operating efficiency and avoiding waste.

[0075] The present disclosure may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0076] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination thereof. As used herein, a computer-readable storage medium is not to be construed as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through an electrical wire.

[0077] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in the computer-readable storage medium in each computing / processing device.

[0078] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., utilizing an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions. The electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A winter adaptive antifreeze system for a chiller unit, wherein the evaporator in the unit includes a chilled water outlet pipe and a chilled water inlet pipe for chilled water circulation, and the evaporator's drain port is connected to the water inlet of a water tank, and the water outlet of the water tank is connected to the chilled water inlet pipe; the water tank is also connected to a gas storage tank, characterized in that: The system comprises: The evaporator antifreeze and emptying subsystem is used to determine whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate of the evaporator, and the circulating water volume. If there is a risk of frozen pipes, the gas in the water tank is pumped into the gas storage tank to reduce the pressure in the water tank, stop the circulation of chilled water, and use the pressure difference between the evaporator and the water tank to completely drain the chilled water from the evaporator into the water tank; The water tank antifreeze protection subsystem is used to determine whether the water tank antifreeze protection is needed based on the temperature and liquid level in the water tank. If necessary, the water tank is heated; The chilled water return subsystem is used to determine whether the chilled water circulation can be restored normally and the pressure reduction in the water tank has stopped. If so, the high-pressure gas in the gas storage tank is discharged into the water tank to increase the pressure in the water tank. The chilled water in the water tank is discharged back into the chilled water inlet pipe by using the pressure difference between the water tank and the chilled water inlet pipe.

2. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The determination of whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate, and the circulating water volume of the evaporator includes: If the following conditions are met simultaneously: ambient temperature ≤ ambient low temperature alarm value, evaporator chilled water flow ≤ chilled water cutoff alarm value, and evaporator flow volume ≥ chilled water low level, and the chilled water cutoff duration lasts for the set duration, the evaporator is judged to have a risk of frozen pipes.

3. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The evaporator antifreeze and emptying subsystem includes an ambient thermometer, a chilled water flow meter and a heat exchange tube level meter; wherein the ambient thermometer is used to detect the ambient temperature; the chilled water flow meter is installed on the chilled water outlet pipe of the evaporator to detect the chilled water flow of the evaporator; the heat exchange tube level meter is installed on the heat exchange tube of the evaporator to detect the circulating water volume of the evaporator.

4. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The evaporator antifreeze and emptying subsystem includes an electric exhaust valve, a vacuum pump, a one-way valve and a water tank pressure sensor installed on the water tank; The electric exhaust valve, vacuum pump and one-way valve are connected in sequence between the air outlet of the water tank and the air inlet of the gas storage tank, and are opened when there is a risk of freezing pipes in the evaporator to extract the gas in the water tank into the gas storage tank to reduce the pressure in the water tank. The electric exhaust valve, vacuum pump and one-way valve are connected in sequence between the air outlet of the water tank and the air inlet of the gas storage tank, and are opened when there is a risk of freezing pipes in the evaporator to extract the gas in the water tank into the gas storage tank to reduce the pressure in the water tank, and are closed after the vacuum pump is turned on for the set vacuum pump evacuation time or when the water tank pressure detected by the water tank pressure sensor is ≤ the vacuum pump closing pressure.

5. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The evaporator antifreeze drain subsystem includes a chilled water outlet electric valve installed on the chilled water outlet pipe of the evaporator, a chilled water inlet electric valve installed on the chilled water inlet pipe, and a drain electric valve installed on the connection channel between the evaporator drain port and the water tank inlet; After the pressure in the water tank is reduced, the chilled water outlet electric valve and the chilled water inlet electric valve are closed to stop the chilled water circulation, and the drain electric valve is opened to utilize the pressure difference between the shell and tube evaporator and the water tank to completely discharge the chilled water of the shell and tube evaporator into the water tank. Then the chilled water outlet electric valve and the chilled water inlet electric valve are opened, and the drain electric valve is closed.

6. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The evaporator antifreeze and emptying subsystem includes a water tank liquid level gauge, which is connected to the water tank and is used to detect the water tank liquid level to calculate the liquid level growth rate and determine whether the evaporator's chilled water has been completely discharged into the water tank. The specific judgment criterion is: if the liquid level growth rate ≤ the water tank liquid level growth rate setting value, it is determined that the evaporator's chilled water has been completely discharged into the water tank.

7. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The water tank antifreeze protection subsystem includes a chilled water pump, a water tank temperature sensor and a water tank electric heater; wherein the chilled water pump is installed on the chilled water inlet pipe; the water tank temperature sensor is installed in the water tank for detecting the temperature in the water tank; The water tank electric heating element is arranged inside the water tank, and is turned on when the water tank antifreeze protection is required to heat the water tank, and is turned off after the water tank electric heating element is turned on for a preset water tank heating time or when the temperature inside the water tank is ≥ the water tank stop heating temperature value; the criterion for the need for water tank antifreeze protection is: the freezing water pump is turned on, the temperature inside the water tank is ≤ the water tank low temperature alarm value, and the water tank liquid level is ≥ the water tank heating liquid level setting value.

8. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The determining whether the chilled water cycle can be restored normally includes: If the chilled water pump on the chilled water inlet pipe is detected to be turned on from off and the chilled water flow rate is greater than the chilled water flow interruption alarm value, it is determined that the chilled water circulation in the evaporator chilled water outlet and inlet pipes can be restored normally.

9. The self-adaptive antifreeze system for chillers in winter according to claim 1, characterized in that: The chilled water return subsystem includes an exhaust electric valve, an air storage tank pressure sensor, and a water tank water outlet electric valve; the exhaust electric valve is connected between the air inlet of the water tank and the air outlet of the air storage tank; the air storage tank pressure sensor is installed on the air storage tank to detect the air storage tank pressure; the water tank water outlet electric valve is set in the connection path between the water tank outlet and the chilled water inlet pipe; The exhaust electric valve opens when the chilled water circulation can be restored normally and the pressure reduction in the water tank has stopped, so as to discharge the high-pressure gas in the gas storage tank into the water tank and increase the pressure in the water tank until the pressure in the gas storage tank is equal to the pressure in the water tank. At this time, the water tank water outlet electric valve opens to utilize the pressure difference between the water tank and the chilled water inlet pipe and the chilled water pump on the chilled water inlet pipe to discharge the chilled water in the water tank back into the chilled water inlet pipe until the water tank liquid level is ≤ the water tank emptying level setting value.

10. A method for adaptively preventing freezing of a chiller in winter, implemented based on the system according to any one of claims 1 to 9, characterized in that: The method comprises: Determine whether there is a risk of frozen pipes in the evaporator based on the ambient temperature, the chilled water flow rate of the evaporator, and the circulating water volume. If there is a risk of frozen pipes in the evaporator, pump the gas in the water tank into the gas storage tank to reduce the pressure in the water tank, stop the chilled water circulation, and use the pressure difference between the evaporator and the water tank to completely drain the chilled water from the evaporator into the water tank. Determine whether antifreeze protection is needed for the water tank based on the temperature and liquid level in the water tank. If necessary, heat the water tank. Determine whether the chilled water circulation can be restored normally and the pressure drop in the water tank has stopped. If so, discharge the high-pressure gas in the gas storage tank into the water tank to increase the pressure in the water tank, and use the pressure difference between the water tank and the chilled water inlet pipe to discharge the chilled water in the water tank back to the chilled water inlet pipe.

11. A chiller, characterized in that: The invention comprises the winter adaptive antifreeze system for a chiller according to any one of claims 1 to 9.

12. An air conditioner, characterized in that: Including the chiller as claimed in claim 11.

13. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to claim 10 is implemented.

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