阅读说明：本技术 一种带有进水预警停机功能的水冷式冷水机组 (Water-cooled water chilling unit with intake early warning shutdown function ) 是由 姜盈霓 于 2019-09-18 设计创作，主要内容包括：本发明涉及一种带有进水预警停机功能的水冷式冷水机组。包括蒸发器、压缩机、冷凝器和热力膨胀阀；在蒸发器的冷冻水入口上的管路上安装有冷冻水泵；在冷凝器的冷却水入口上的管路上安装有冷却水泵；蒸发器的制冷剂出口连接至压缩机的制冷剂入口,压缩机的制冷剂出口连接至冷凝器的制冷剂入口,冷凝器的制冷剂出口连接至蒸发器的制冷剂入口；在冷凝器的制冷剂出口上的管路上还设有密度测量组件；在压缩机的制冷剂出口上的管路上还安装有电动三通阀,在蒸发器的制冷剂入口上的管路上还设有电磁阀；还包括一个旁通管路,该旁通管路的一端连接至电动三通阀的第二出口、另一端与蒸发器的制冷剂入口上的管路对接连接。本发明结构简单、响应迅速。(the invention relates to a water-cooled water chilling unit with a water inlet early warning and stopping function. Comprises an evaporator, a compressor, a condenser and a thermostatic expansion valve; a chilled water pump is arranged on a pipeline on a chilled water inlet of the evaporator; a cooling water pump is arranged on a pipeline on a cooling water inlet of the condenser; the refrigerant outlet of the evaporator is connected to the refrigerant inlet of the compressor, the refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser, and the refrigerant outlet of the condenser is connected to the refrigerant inlet of the evaporator; a density measuring assembly is also arranged on a pipeline on a refrigerant outlet of the condenser; an electric three-way valve is also arranged on a pipeline on a refrigerant outlet of the compressor, and an electromagnetic valve is also arranged on a pipeline on a refrigerant inlet of the evaporator; the evaporator also comprises a bypass pipeline, wherein one end of the bypass pipeline is connected to the second outlet of the electric three-way valve, and the other end of the bypass pipeline is in butt joint connection with a pipeline on the refrigerant inlet of the evaporator. The invention has simple structure and quick response.)

1. The utility model provides a water-cooled cooling water set with early warning shutdown function of intaking, characterized by: comprises an evaporator (3), a compressor (6), a condenser (9) and a thermostatic expansion valve (5); a chilled water inlet and a chilled water outlet of the evaporator (3) are respectively connected to a water return port and a water supply port of a user (1) through pipelines, and a chilled water pump (2) is mounted on the pipeline of the chilled water inlet of the evaporator (3); a cooling water inlet and a cooling water outlet of the condenser (9) are respectively connected to a water outlet and a water inlet of the cooling tower (13) through pipelines, and a cooling water pump (12) is installed on the pipeline on the cooling water inlet of the condenser (9); a refrigerant outlet of the evaporator (3) is connected to a refrigerant inlet of the compressor (6) through a pipeline, a refrigerant outlet of the compressor (6) is connected to a refrigerant inlet of the condenser (9) through a pipeline, a refrigerant outlet of the condenser (9) is connected to a refrigerant inlet of the evaporator (3) through a pipeline, a filter (7) is further arranged on the pipeline, and a thermostatic expansion valve (5) is installed on the pipeline;

A density measuring assembly is also arranged on a pipeline on a refrigerant outlet of the condenser (9), and comprises a detection box (11) and a density analyzer (10) arranged on the detection box (11);

A single-input and double-output electric three-way valve (8) is also arranged on a pipeline on a refrigerant outlet of the compressor (6), and an electromagnetic valve (4) is also arranged on a pipeline on a refrigerant inlet of the evaporator (3); the evaporator also comprises a bypass pipeline, wherein one end of the bypass pipeline is connected to a second outlet of the electric three-way valve (8), and the other end of the bypass pipeline is in butt joint connection with a pipeline on a refrigerant inlet of the evaporator (3);

the device is characterized by further comprising a controller, wherein the freezing water pump (2), the cooling water pump (12), the electric three-way valve (8), the electromagnetic valve (4), the compressor (6) and the density analyzer (10) are all electrically connected with the controller.

2. The water-cooled chiller unit with intake warning shutdown function of claim 1, characterized by: the evaporator (3) is selected as a shell-and-tube evaporator and comprises an evaporation shell and a refrigerant coil positioned in the evaporation shell, a cooling water inlet and a cooling water outlet are arranged on the evaporation shell, and two ends of the refrigerant coil penetrate out of the same end of the evaporation shell to form the refrigerant inlet and the refrigerant outlet.

3. The water-cooled chiller unit with intake warning shutdown function of claim 2, characterized by: the condenser (9) is selected to be a shell-and-tube condenser and comprises a condensation shell and a cooling water coil pipe positioned inside the condensation shell, a refrigerant inlet and a refrigerant outlet are formed in the condensation shell, and two ends of the cooling water coil pipe penetrate out of the same end of the condensation shell to form a cooling water inlet and a cooling water outlet.

4. The water-cooled chiller unit with intake warning shutdown function of claim 3, characterized by: the density analyzer (10) is selected as an ultrasonic density analyzer; the detection box (11) comprises a box body, the density analyzer (10) is installed on the side wall of the box body, and the probe part of the density analyzer is located in the inner cavity of the box body.

5. The water-cooled chiller unit with intake warning shutdown function of claim 4, characterized by: still include audible-visual annunciator, this audible-visual annunciator is connected to the controller.

Technical Field

the invention belongs to the technical field of water chilling units, and particularly relates to a water-cooled water chilling unit with a water inlet early warning and shutdown function.

Background

Water chilling units, also known as freezers, refrigerators, chillers, etc., are widely used in various industries. The water-cooled water chilling unit utilizes a shell-and-tube evaporator to carry out heat exchange between water and a refrigerant, the refrigerant evaporates and absorbs heat in the water to cool the water to generate cold water required by a user, then the refrigerant is brought to a shell-and-tube condenser under the action of a compressor, the refrigerant and the cooling water carry out heat exchange, and the cooling water absorbs the heat and then brings the heat out to an external cooling tower through a water pipe to dissipate. The working process is as follows: the low-temperature low-pressure refrigerant gas after evaporation and refrigeration is sucked by a compressor at the beginning and then compressed into high-temperature high-pressure gas to be sent to a condenser; the high-temperature high-pressure gas is cooled by a condenser and then is condensed into normal-temperature high-pressure liquid; when the normal-temperature high-pressure liquid flows into the thermostatic expansion valve, the normal-temperature high-pressure liquid is throttled into low-temperature low-pressure wet vapor, and the wet vapor flows into the shell-and-tube evaporator to absorb the heat of the chilled water in the evaporator so as to reduce the temperature of the chilled water; the evaporated refrigerant is sucked back into the compressor and the next refrigeration cycle is repeated.

The existing water-cooled water chilling unit has large water consumption because the cooling water is an open system (in a cooling tower, the cooling water is in flowing contact with air for heat dissipation, and part of the cooling water is lost into the air due to evaporation), and water needs to be continuously supplemented into the system. The water quality of the supplementary water source changes, and in addition, particle impurities in the air enter the cooling water in the flowing contact heat dissipation process of the cooling water and the air, so that the water quality of the cooling water is deteriorated in the long-term operation process of the unit, and the scaling and corrosion of the pipe wall of the condenser of the water chilling unit are accelerated. When the wall of the condenser is damaged, the cooling water will enter the refrigerant piping system and thus eventually the compressor, and is incompressible as compared to the ability of the refrigerant to switch between a gaseous state and a liquid state (i.e., with greater compressibility), such that the cooling water enters the refrigerant system and enters the compressor along the refrigerant system, breaking down the motor coils of the compressor, causing catastrophic damage to the entire unit. If the accident happens, the accident can be found and emergently processed in a short time, the unit can be used after being overhauled, but the refrigeration efficiency can be obviously reduced, and if the accident is not processed for a long time, the unit can only be scrapped, so that serious economic loss is caused.

Therefore, a scheme capable of timely discovering and timely processing the working condition of the wall damage of the condenser pipe is needed to ensure that the water chilling unit cannot be further damaged or even scrapped when the above problems occur, and the technical scheme does not exist in the prior art.

Disclosure of Invention

The invention provides a water-cooled water chilling unit with a water inlet early warning shutdown function, which has a simple structure and quick response and solves the technical problems in the prior art, and further unit loss is avoided by timely finding that cooling water enters a refrigerant pipeline and timely early warning shutdown.

the technical scheme adopted by the invention for solving the technical problems in the prior art is as follows: a water-cooled water chilling unit with intake early warning shutdown function comprises an evaporator, a compressor, a condenser and a thermal expansion valve; a chilled water inlet and a chilled water outlet of the evaporator are respectively connected to a water return port and a water supply port of a user through pipelines, and a chilled water pump is mounted on the pipeline of the chilled water inlet of the evaporator; a cooling water inlet and a cooling water outlet of the condenser are respectively connected to a water outlet and a water inlet of the cooling tower through pipelines, and a cooling water pump is arranged on the pipeline on the cooling water inlet of the condenser; the refrigerant outlet of the evaporator is connected to the refrigerant inlet of the compressor through a pipeline, the refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser through a pipeline, the refrigerant outlet of the condenser is connected to the refrigerant inlet of the evaporator through a pipeline, a filter is further arranged on the pipeline, and the thermal expansion valve is installed on the pipeline; a density measuring assembly is also arranged on a pipeline on a refrigerant outlet of the condenser, and comprises a detection box and a density analyzer arranged on the detection box; a single-input and double-output electric three-way valve is also arranged on a pipeline on a refrigerant outlet of the compressor, and an electromagnetic valve is also arranged on a pipeline on a refrigerant inlet of the evaporator; the evaporator also comprises a bypass pipeline, wherein one end of the bypass pipeline is connected to a second outlet of the electric three-way valve, and the other end of the bypass pipeline is in butt joint connection with a pipeline on a refrigerant inlet of the evaporator; the device also comprises a controller, wherein the chilled water pump, the cooling water pump, the electric three-way valve, the electromagnetic valve, the compressor and the density analyzer are electrically connected with the controller.

The invention has the advantages and positive effects that: compared with the existing water chilling unit, the technical scheme has the advantage that the density measuring assembly is arranged on the pipeline of the refrigerant outlet of the condenser, so that the technical effect of detecting the density of the refrigerant at the refrigerant outlet of the condenser is achieved. The working condition that the cooling water that the damaged condenser pipe wall leads to gets into refrigerant pipe-line system is found to the density value through continuously detecting and monitoring to the refrigerant, and control whole cooling water set when finding above-mentioned unusual working condition and in time shut down and maintain, effectively avoided sneaking into the refrigerant flow of cooling water and get into the compressor behind pipeline and the evaporimeter, for the compressor provides the protection, avoid the compressor damage to lead to scrapping. Through setting up the bypass line, realized passing through the leading-in evaporimeter of bypass line with compressor exhaust refrigerant after detecting the condition that the refrigerant pipeline intakes, formed the self-loopa of the inside refrigerant of system in the twinkling of an eye that stops, avoided the refrigerant to continue leading-in to the condenser, avoided the waste of refrigerant, also be convenient for follow-up maintenance to the condenser and handle, greatly avoided economic loss.

Preferably: the evaporator is selected as a shell-and-tube evaporator and comprises an evaporation shell and a refrigerant coil positioned inside the evaporation shell, a chilled water inlet and a chilled water outlet are formed in the evaporation shell, and two ends of the refrigerant coil penetrate out of the same end of the evaporation shell to form the refrigerant inlet and the refrigerant outlet.

Preferably: the condenser is selected to be a shell-and-tube condenser and comprises a condensation shell and a cooling water coil positioned inside the condensation shell, a refrigerant inlet and a refrigerant outlet are arranged on the condensation shell, and two ends of the cooling water coil penetrate out of the same end of the condensation shell to form a cooling water inlet and a cooling water outlet.

Preferably: the density analyzer is selected as an ultrasonic density analyzer; the detection box comprises a box body, the density analyzer is installed on the side wall of the box body, and the probe part of the density analyzer is located in the inner cavity of the box body.

Preferably: still include audible-visual annunciator, this audible-visual annunciator is connected to the controller.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of the density analyzer and detection box of FIG. 1;

Fig. 3 is a block diagram of the electronic control system of the present invention.

In the figure: 1. a user; 2. a chilled water pump; 3. an evaporator; 4. an electromagnetic valve; 5. a thermostatic expansion valve; 6. a compressor; 7. a filter; 8. an electric three-way valve; 9. a condenser; 10. a density analyzer; 11. a detection box; 12. a cooling water pump; 13. and (5) cooling the tower.

Detailed Description

in order to further understand the contents, features and effects of the present invention, the following embodiments are described in detail as follows:

Referring to fig. 1, the water-cooled chiller with water inlet warning and shutdown functions of the present invention includes an evaporator 3, a compressor 6, a condenser 9 and a thermostatic expansion valve 5.

The chilled water inlet and the chilled water outlet of the evaporator 3 are respectively connected to the water return port and the water supply port of the user 1 through pipelines, and the chilled water pump 2 is installed on the pipeline of the chilled water inlet of the evaporator 3. The chilled water pump 2 circulates chilled water between the evaporator 3 and the user 1, and the chilled water from the user 1 exchanges heat with the refrigerant in the evaporator 3 to be cooled, and accordingly the refrigerant absorbs heat to be heated and gasified.

A cooling water inlet and a cooling water outlet of the condenser 9 are respectively connected to a water outlet and a water inlet of a cooling tower 13 through pipelines, and a cooling water pump 12 is installed on the pipeline of the cooling water inlet of the condenser 9. The cooling water pump 12 circulates cooling water between the condenser 9 and the cooling tower 13, the cooling water from the cooling tower 13 exchanges heat with the refrigerant in the condenser 9, the refrigerant is liquefied to release heat, and the cooling tower 13 dissipates the heat absorbed by the cooling water to the surrounding environment.

The refrigerant outlet of the evaporator 3 is connected to the refrigerant inlet of the compressor 6 by a pipe, the refrigerant outlet of the compressor 6 is connected to the refrigerant inlet of the condenser 9 by a pipe, the refrigerant outlet of the condenser 9 is connected to the refrigerant inlet of the evaporator 3 by a pipe and a filter 7 is further provided on the pipe, and a thermostatic expansion valve 5 is also provided on the pipe. The filter 7 is used for filtering particulate impurities possibly contained in the refrigerant, so that the refrigerant is kept in a pure state. The thermostatic expansion valve 5 is used as a part for controlling the state conversion of the refrigerant, and after passing through the thermostatic expansion valve 5, the front normal-temperature high-pressure liquid is converted into the rear low-temperature low-pressure wet vapor (i.e. a mixed state of partial liquid and partial gas).

The refrigerant circulates in the structure, and the circulation process is as follows: the refrigerant gas of low temperature and low pressure obtained after the evaporator 3 is evaporated and refrigerated is sucked by the compressor 6 at the beginning, then the refrigerant gas is compressed into high temperature and high pressure gas and sent to the condenser 9; the high-temperature high-pressure gas is cooled in the condenser 9 and then condensed into normal-temperature high-pressure liquid; the normal temperature high pressure liquid flows into a thermostatic expansion valve 5, forms low temperature low pressure wet steam through throttling, then flows into an evaporator 3, absorbs the heat in the freezing water in the evaporator 3 to reduce the temperature of the water; the evaporated refrigerant gas is sucked back into the compressor 6.

In this embodiment, the evaporator 3 is a shell-and-tube evaporator, and includes an evaporation shell and a refrigerant coil inside the evaporation shell, the chilled water inlet and the chilled water outlet are disposed on the evaporation shell, and two ends of the refrigerant coil penetrate out from the same end of the evaporation shell to form the refrigerant inlet and the refrigerant outlet.

In this embodiment, the condenser 9 is a shell-and-tube condenser, and includes a condensation shell and a cooling water coil inside the condensation shell, the refrigerant inlet and the refrigerant outlet are disposed on the condensation shell, and the two ends of the cooling water coil penetrate out from the same end of the condensation shell to form the cooling water inlet and the cooling water outlet.

A density measuring assembly is also arranged on a pipeline at the refrigerant outlet of the condenser 9, and comprises a detection box 11 and a density analyzer 10 arranged on the detection box 11. The density measuring assembly is used for detecting the density change of the refrigerant discharged from the refrigerant outlet of the condenser 9, and judging whether the pipe wall of the condenser 9 is broken and whether cooling water enters the refrigerant circulating pipeline or not according to the density change. The principle of judgment is as follows: when the pipe wall is not broken and the refrigerant is in normal circulation, the density value detected by the density measuring component is relatively stable, and the whole water chilling unit is in a stable operation condition; when the pipe wall is broken and cooling water enters the pipeline, the density measuring component can detect the density change of the refrigerant at the refrigerant outlet of the condenser 9, and the density change corresponds to the change of the refrigerant composition, so that the conclusion of pipeline water inlet can be judged.

In this embodiment, the density analyzer 10 is selected as an ultrasonic density analyzer. The working principle of the ultrasonic density analyzer is as follows: when ultrasonic waves are incident from one medium to another medium, reflection, refraction, mode conversion, and the like occur at the interface between the media due to the difference in propagation speeds between the two media. The frequency of the ultrasonic waves is generally higher than 20kHz, and the ultrasonic waves can only propagate in the liquid medium in the form of longitudinal waves. The phase, frequency, speed and attenuation of its propagation are affected by the properties of the medium, and the density of the liquid is measured by establishing a corresponding parameter relation between the propagation properties of the ultrasonic waves and the density of the liquid. The main advantages are: non-contact measurement can be realized, the measurement precision is high, and the response is fast; and no moving part exists, so that the measurement stability is better; has no radioactivity and is harmless to human body.

The density analyzer 10 is a commercially available component and will not be described in detail. The model can be selected as follows: the F2000 series ultrasonic densitometer of FIL corporation, usa is a precision instrument that uses the principle of ultrasonic waves and integrates multiple detection techniques. The ultrasonic detection is not influenced by the turbidity, the chromaticity and the conductivity of a medium and is not interfered by flow state and impurities, and the real-time accurate measurement of the instrument is ensured by the design of a built-in high-precision thermal resistance temperature measuring element and a durable sensor. The instrument is simple to adjust and convenient to operate, and is an easy-to-use instrument. The device has 16-bit precision 4-20mA analog quantity output and SPST relay output, has a 2-wire RS-485 physical interface, and can select ModBus-RTU or Profibus-DP communication protocols.

The working principle is as follows:

after the ultrasonic probe emits a beam of ultrasonic signal, the signal passes through liquid with certain concentration and reaches the opposite reflecting surface, and then the signal returns from the reflecting surface. At the moment, the probe is converted into a signal receiving state, the total time of ultrasonic signal transmission is measured once, the distance of signal transmission is 2 times of the distance, and the distance divided by the time is the ultrasonic sound velocity. The propagation speed of an ultrasonic signal in a liquid medium is a function of density and temperature over a range of densities. After calibration and temperature compensation, the ultrasonic density analyzer can accurately measure the density of the liquid medium.

The detection box 11 comprises a box body, the density analyzer 10 is arranged on the side wall of the box body, and the probe part of the density analyzer is positioned in the inner cavity of the box body. The detection box 11 is used as a buffered box body, the refrigerant liquid flowing out of the pipeline enters the detection box 11 to be buffered, the flow rate of the refrigerant in the pipeline is high under normal conditions, the operation of the density analyzer 10 is not facilitated under the conditions, and when the refrigerant is buffered in the detection box 11 and the flow rate is reduced, the normal operation of the density analyzer 10 is facilitated. The detection box 11 is also used as a mounting platform/support of the density analyzer 10, an inlet and an outlet are arranged at the top and the bottom of the box body of the detection box 11, the inlet and the outlet can be connected to a pipeline at a refrigerant outlet of the condenser 9 after being butted with the pipeline, the detection box 11 is preferably of a detachable structure, can be detached from the pipeline, is cleaned and maintained and then is mounted again, and the accuracy and the stability of density measurement are ensured.

Fig. 2 shows the installation relationship between the density analyzer 10 and the detection box 11, and the F2000 series ultrasonic density analyzer of FIL corporation of usa structurally includes an instrument header, a central rod and a probe, wherein a mounting substrate with a plurality of connecting holes is arranged in the middle of the central rod, the probe is installed at the front end of the central rod, and the rear end of the central rod is connected with the instrument header. The instrument meter is characterized in that a circuit board is arranged in the instrument meter head, a display screen is arranged on the instrument meter head, the central rod is used as a support rod and contains a lead wire, and the probe comprises an ultrasonic transmitting and receiving end and a reflecting end opposite to the ultrasonic transmitting and receiving end. During installation, the installation substrate is fixedly connected with the side wall of the box body of the detection box 11, the meter head is positioned outside, the probe is positioned in the inner cavity of the box body, and when the box body is filled with the refrigerant, the probe is immersed in the refrigerant.

A single-input and double-output electric three-way valve 8 is further installed on a pipeline on a refrigerant outlet of the compressor 6, a pipeline on the refrigerant outlet of the compressor 6 is connected with an inlet of the electric three-way valve 8, a pipeline on a refrigerant inlet of the condenser 9 is connected with a first outlet of the electric three-way valve 8, and a solenoid valve 4 is further installed on a pipeline on a refrigerant inlet of the evaporator 3.

And the evaporator also comprises a bypass pipeline, wherein one end of the bypass pipeline is connected to the second outlet of the electric three-way valve 8, and the other end of the bypass pipeline is in butt joint connection with a pipeline on the refrigerant inlet of the evaporator 3. The electromagnetic valve 4 controls the on-off of the pipeline, and the electric three-way valve 8 controls the switching between the normal pipeline and the bypass pipeline. Under normal conditions, the electric three-way valve 8 communicates the refrigerant outlet of the compressor 6 with the refrigerant inlet of the condenser 9, and the bypass pipeline is idle; when the system is stopped due to the abnormal water inflow of the refrigerant pipeline, the electric three-way valve 8 and the electromagnetic valve 4 synchronously act and respond to switch the pipeline to the bypass pipeline and cut off the pipeline where the electromagnetic valve 4 is positioned, and high-pressure refrigerant discharged from the compressor 6 enters the evaporator 3 through the bypass pipeline at the moment of stopping, so that the refrigerant is prevented from being continuously fed into the condenser 9, the impact on the whole pipeline system during sudden stopping is relieved, the refrigerant is saved, and the subsequent maintenance treatment on the condenser 9 is facilitated.

Referring to fig. 3, the water-cooled chiller further includes a controller, and the chilled water pump 2, the cooling water pump 12, the electric three-way valve 8, the electromagnetic valve 4, the compressor 6 and the density analyzer 10 are all electrically connected to the controller. The controller receives signals from the density analyzer 10, obtains density values through processing, compares the density values with historical data to obtain density change conditions, and further obtains judgment of whether the pipe wall of the condenser 9 is damaged and whether the refrigerant pipeline is filled with water, when the judgment is in the abnormal working condition, the controller controls the cooling water pump 12 and the compressor 6 to stop running synchronously, the freezing water pump 2 stops running (prevents freezing water in the evaporator 3 from freezing) after running for a certain time (about 3 minutes), and simultaneously controls the valve core of the electric three-way valve 8 to deflect to switch on the bypass pipeline and control the electromagnetic valve 4 to close so as to switch off the pipeline between the refrigerant outlet of the condenser 9 and the refrigerant inlet of the evaporator 3.

The controller comprises a circuit board, and a controller chip (such as a PLC chip) is arranged on the circuit board and used as a processor; the density analyzer further comprises a conversion module for performing analog-to-digital conversion on the analog signal transmitted by the density analyzer 10, the conversion module is in communication connection with the controller chip, and the processed density digital signal is received by the controller chip; the density analyzer further comprises a storage module for storing historical data/standard density data, the storage module is in communication connection with the controller chip, and the density value obtained by the density analyzer 10 is compared with the difference value of the historical data or the standard density data to obtain a density change conclusion; the controller also comprises motor driving modules of the chilled water pump 2, the cooling water pump 12 and the compressor 6, and each motor driving module is in communication connection with the controller chip and controls the on-off of the chilled water pump 2, the cooling water pump 12 and the compressor 6; the controller also comprises driving modules of the electric three-way valve 8 and the electromagnetic valve 4, and each driving module is in communication connection with the controller chip and respectively controls the switching action and the on-off action of the electric three-way valve 8 and the electromagnetic valve 4. The density measurement time interval of the density analyzer 10 can be selectively set in the density analyzer 10, and the F2000-series ultrasonic density analyzer has a function of setting a sampling frequency, and can set the sampling time interval according to a need in the field.

In the embodiment, the alarm device further comprises an audible and visual alarm, the audible and visual alarm is connected to the controller, and when the controller detects an abnormal conclusion, the audible and visual alarm sends out an audible and visual alarm signal to prompt personnel to perform timely treatment.

The working process of the embodiment:

Under normal conditions, the compressor 6 sucks low-temperature and low-pressure refrigerant gas obtained after evaporation and refrigeration of the evaporator 3 through a pipeline, then compresses the refrigerant gas into high-temperature and high-pressure gas, and conveys the gas to the condenser 9 through a pipeline; the high-temperature high-pressure gas is cooled in the condenser 9 and then condensed into normal-temperature high-pressure liquid; then the normal temperature high pressure liquid flows into the filter 7 through the pipeline, flows into the thermostatic expansion valve 5 after being filtered, forms low temperature low pressure wet vapor through throttling, then the refrigerant flows into the evaporator 3 along the pipeline, absorbs the heat in the freezing water in the evaporator 3 to reduce the temperature of the water; the evaporated refrigerant gas is sucked back into the compressor 6 to form a cycle; in the process, the heat in the chilled water from the user 1 is continuously absorbed by the refrigerant and kept at a low temperature, and the heat is finally dissipated to the ambient environment by the cooling tower 13, and the density signal measured by the density analyzer 10 is normal in the whole process.

Along with the increasing of the operation time, due to factors of water replenishing in the cooling tower 13, entering of external impurities and the like, scaling and corrosion phenomena occur on the pipe wall of a cooling water coil in the condenser 9 of the water chilling unit, the problem of pipe wall damage is caused after corrosion to a certain degree, cooling water enters a refrigerant pipeline system, mixed liquid of the cooling water and the refrigerant is discharged along a pipeline through a refrigerant outlet of the condenser 9 and enters the detection box 11, a density signal measured by the density analyzer 10 is collected by the controller, and the controller obtains a conclusion of density change, cooling water mixing and pipe wall damage. Then the controller controls the cooling water pump 12 and the compressor 6 to stop, the freezing water pump 2 stops running (preventing freezing water in the evaporator 3 from freezing) after continuing running for a certain time (about 3 minutes), and the valve core deflection of the electric three-way valve 8 and the electromagnetic valve 4 are controlled to be turned off at the same time, so that the bypass pipeline which is turned on at the moment of stopping effectively avoids the impact on the pipeline at the moment of closing the valve, and can prevent the refrigerant from entering the condenser 9 again.

The audible and visual alarm gives an alarm, a maintenance worker overhauls the stopped water chilling unit and eliminates faults (such as replacing the condenser 9, maintaining the condenser 9 and reinstalling the condenser), then the controller restores the valve core position of the electric three-way valve 8 and the opening state of the electromagnetic valve 4, the chilled water pump 2, the cooling water pump 12 and the compressor 6 are started to restore the operation of the three, and then the water chilling unit continues to be put into operation.