How to deal with the leakage of CRAC precision air-conditioner refrigerant?

CRAC，As is known to all, large equipment power density of high calorific value, so the volume data exchange, such as computer room still needs through constant refrigeration air-conditioning compressor to meet the needs of communications equipment to the environment temperature, the refrigerant through the pump running, the ethylene glycol solution as the carrier of cold agent for indoor and outdoor heat exchanger, prevent air conditioning compressor work, because the computer room precision air conditioning evaporator left and right sides of the joint is more, the likely funnelled more also, precision air conditioning refrigerant leakage is often the case, the main reason is that air conditioner factory employees poor welding technology, in the absence of the copper pipe burn red (did not reach a temperature of 600 ℃ ~ 600 ℃), just put the electrode in joint, copper tube and solder was not able to fuse together, causing joint holder welding, MaZha, leakage is not smooth, look at this several air conditioning refrigerant leakage point below how to patching.

Room for the newly installed the air conditioner, close the end of the valve, outdoor atmosphere to eliminate indoor machine, indoor machine evaporator leakage ring accidentally use ears to hear, visible leaking air conditioner, evaporator solder joints is put into a neglected, invented the evaporator leakage, the best welding, it lest the evaporator heat plastic shell deformation, helpless to the user account, assembly method is:
1. Find the missing spots and mark them well.
2. If there is another refrigerant in the refrigeration system, the refrigerant should be put into the outdoor unit first.
3. Unscrew the indoor machine with two 8-inch or 10-inch wrenches and unpack the electric box on the right side of the indoor machine.
4. Remove the rear of the evaporator and remove the strong pipe and splint, remove the indoor evaporator and position the screw.
5. The left hand lifts the pipe slightly from the back side of the chamber to make the evaporator move forward.
Pull the evaporator out of 5cm with your right hand, twist the evaporator 90 degrees with your hands and pull it out of the pipe.
Watch your hands for control. Don't touch the fins.
After the evaporator is unloaded, place it in a flat, clean place and wipe the oil stains with dry cloth.
The leakage point is soldered by silver solder, and the introspection must not leak, and the evaporator will be loaded back into the plastic frame of the indoor machine according to the assembly's reverse order.
Negative pressure sampling and density determination of refrigerant
(1) most of the lithium bromide absorption machine room air conditioning unit positive pressure sampling (hot and cold water unit) with the solution of the pump pressure is higher, dilute solution under the condition of positive pressure sampling, positive pressure sampling instruments and connections needed.
Sampling libr absorption (2) computer room air conditioning refrigeration unit (hot and cold water unit) of internal pressure is lower than the atmospheric pressure, in the cold agent sample, due to the low cooling pump pressure, the outlet pressure is lower than the atmospheric pressure, under the condition of negative pressure sampling, with the help of vacuum pump in the vacuum, the cooling water extract, concentrated solution of pressure is lower than the atmospheric pressure, if you need sample, under the condition of negative pressure sampling is required as well.
Some lithium bromide absorption units (cold and hot water units) have low pressure and dilute solution.
Negative pressure needed for the sampling instrument and its connection, in the management and maintenance of the equipment operation, sampling by dry cooling water or less concentrated solution, such as using the jar is not convenient, can replace jar with sampler.
(3) density determination of the density of the lithium bromide solution, is to determine the concentration of the solution, the concentration, temperature and density is directly related to the three parameters, determine the density and temperature, can determine the concentration of solution, amount of lithium bromide solution into the barrel should be measured as soon as possible, after determination, thermometer and densimeter amount must be inserted into the barrel, reading at the same time.
(4) computer room air conditioning temperature and density is measured, for example, the measured temperature of 30 ℃, density of 1560 kg/m3 find 30 ℃ for vertical line, on the horizontal coordinate of the vertical coordinates to find 1560 kg/m3 as a horizontal line, intersection of two lines can quality of lithium bromide solution concentration of 52% (mass fraction) refrigerant several leak and patching method:
(1) the cooling system of the low-pressure bypass valve core refrigerant is used to make up the refrigerant (commonly known as "gaff"), and it is necessary to raise the injection from the low pressure side.
With a thimble with a thimble, open the low pressure gas valve rod, and the air conditioner of the refrigerant cylinder of the r22 refrigerant gas is connected to the air conditioner.
The result of the leakage of the valve core is that the top pin of the air tube is too long, and the side air valve thimble is not less than the return of the cartridge, so that the valve core is not less than the reset.
The solution is to insert the key of the public air conditioner into the gas valve core to give a force to the valve core, so that the valve core spring will pop up, thus eliminating the leakage of the valve core.
(2) the leakage of the leaking pipeline of the hollow refrigerant of the pipeline is more than that of the family.
Some decorated workers do not understand refrigerant in the refrigerating line;
Bend at will, because there is insulation cover outside the line, the bent is not easy to be invented.
After the hollow of the pipeline, the refrigerant was omitted, and the cooling system was switched on again, and the cooling system presented two stop-flow symptoms.
Example: a split air conditioner is not refrigerated with pressure gauge, pressure gauge shows negative pressure, the gas is added to 0.45mpa, and the compressor is enlarged and the chamber machine has no air.
Remove the outer casing of the chamber, touch the evaporator not cool, peel off the indoor pipe insulation cover, and invent the low-pressure liquid pipe concave.
Use the cutter to remove the concave closure, adopt the method of the outer casing butt joint, and then, after the silver solder is welded, repress, leak, remove, and fluorine, and start up with the remote control.
However, the air conditioner inherits the above symptoms and clarifies that there are two other intercepting points in the pipeline.
The external pipe was stripped of the insulation cover and the low-pressure gas pipe was dented.
After finishing the outdoor piping, start the machine with the remote control and refrigerate the air conditioner.
(3) there are more leakage from the three copper pipes on the four valves of the air conditioner of the four-way reversing valve, and if there is oil trace at the Angle of the invention, the leakage point is clarified.
Band-aid approach is: first the Angle with a towel to clean oil stains, remember and washing spirit leak detection, the funnelled make logo with steel needle, and then release the refrigerant, the four-way reversing valve wound with a wet towel to cool.
When welding, be sure to control the flame skill according to its own control, aiming at the leakage point, and when the Angle reaches the welding temperature, the agile spot silver welding rod welding.
The maneuver should be quick, for the welding win, the test pressure.
The beginners are faced with the failure of the interangle of the four-way reversing valve. It is better to use the adhesive method to fill the leakage.
The core of nylon valve is close to the leakage point, and there is some difficulty in the welding. Improper operation will bake the core.
Once the four-way valve slider is in the air, the air conditioner is cold and hot, and it is a small failure of the original micro leak and becomes a non-changing four-way valve.
This gives users time and financial losses.
The four - way valve Angle gluing method is the same as the glue method of the compressor, after the test pressure leak detection, the pumping air, the air conditioner to the valve Angle leakage failure can be eliminated, the recovery of refrigeration.
(4) tightening machine terminal refrigerant leakage tightening machine terminal refrigerant leakage, accounted for over 2% of the leaking problem, over-current overheat protector cover, if there is oil stains, see tightening machine around the terminal has funnelled to clarify.
The solution is to unplug the air conditioner and write the note "someone fix the air conditioner on the roof, and the plug power" is attached to the socket.
To avoid the external retrencher at the top of the staff;
The indoor staff mistook the power to form a personal shock.
Then the pressure of the system is tested by adding the F22 table to the low pressure gas and the bypass valve.
If the pressure in the system is zero at this time, can be the first to system into 0.3 MPa pressure refrigerant gas, there is no pressure in the lest system, when leak detection by washing spirit, funnelled into tight oil washing spirit through the process, form a tightening machine shaft confound.
Pressure meter test system is under pressure, can be used to wash out the foam to reflect the leakage point of the post to do a sign.
Use dry cloth to adhere to the alcohol to wipe off the oil stains around the terminal posts, and use sandpaper to polish the new material around the terminal, and then use the hacksaw blade to mark the new baller, and to facilitate adhesion.
When the system pressure reaches negative 0.1mpa, the system will be used to make the system with a 1:1 ratio of C31 double pipe glue and apply it to the terminal.
For refrigeration system under vacuum condition, that C31 microcomputer infiltration seep into funnelled glue, funnelled glue also need 100 w light bulb in the adhesive after bake for 30 minutes, make glue into seep into funnelled more easily.
Be careful not to get too close to the C31 glue. It is appropriate to use the C31 glue 20cm. Otherwise, the gel will be baked and flow to the tightening machine. It will cause the leakage to be low.
After two hours of glue, the clamping machine can suppress and leak.
At the end of the time, fluoridation test, the cooling.
(5) the capillary shock outdoor ground leak air conditioner refrigeration, the refrigerant leakage reason reason, otherwise can happen when tightening machine work, make the two pipe friction occurs resonance, grinding wall leakage, the refrigerant.
Example: a hisense kfr-33g split air conditioner does not refrigerate, reflecting on the invention of capillary mill leakage.
The solution: the 6mm copper tube saw, wrapped in the capillary leak, and then silver soldered.
Also can be changed to the inner diameter of the capillary tube with the specification.
No flammable and explosive material shall be found in 1.5m before the replacement of welding.
The front of the capillaries must be covered with iron plates.
Welding flame don't too big, it is advisable to use neutral flame of fire, the temperature reaches 600 ℃, agile put the silver electrode weld crater.
Solder and copper tube melt together, the welding gun is agile apart, or it will burn the capillary.
This type of skill should be gradually understood by the staff while welding, and gradually control the welding skills.
(6) tightening machine outside u-shaped tube refrigerant leakage outdoor tightening machine U exhaust pipe leakage is wide, the main reason is because the brass tube wall thin, poor material, a u-shaped bend after bending, presents the small crack, tightening machine in the work of volatility to crack.
This kind of leakage problem mostly can leak the gas, wait for the indoor machine without cool breeze blow out, classics introspection is invented.
The test method is: wipe the oil trace with a soft cloth on the net, and weld the copper tube crack leak with silver solder.
Before welding, find a copper tube that is larger than the outer diameter of the exhaust pipe, and use a hacksaw saw to open and wrap in the crack, so as to avoid the leakage from this place.
Culture when remove the u-shaped tube of avoid by all means, it will make the tightening machine out of the low temperature low pressure refrigerant gas indirectly into the condenser, the condenser cooling down, refrigeration to low, at the same time, a volatile when tightening machine work.
After u-tube welding, add R22 gas from the end of the low pressure gas.
Test pressure leak detection, if there is no air bubble from the weld, explain the leakage of u-shaped pipe.

The function of the data center expert management CRAC

CRAC has developed a number of other positions, such as cloud engineers, IT architects, and other positions with the rapid development of technology in the data center. But data center experts are still the mainstay of the day-to-day operation of the data center, and there are some important functions to manage the data center in the IT organization.

Monitoring system: Data Center experts implement, support and use various monitoring and management tools in application programs, resource repositories or physical facilities, observe critical alerts, and respond to events in time. They can use real-time monitoring to observe the operation process of each system and improve progress, such as allocate more storage space to the current storage restricted workload.
Integration: Data Center experts need to ensure that systems, services, and applications can work properly in deployment or integration. This requires an in-depth understanding of the system configuration and the interdependence of the system application components within the data center. Experts need to constantly improve or upgrade some components, such as installing system, maintenance system, cable and other infrastructure constantly, so as to save money and improve performance.
Troubleshooting: Data Center experts need to access logs and monitoring data, provide first level and two level support, and use root cause analysis technology to troubleshoot. Experts follow the established event management procedures to ensure that the IT Department has fully responded, and fully communicated with the downtime problem, ensuring real-time follow-up and timely and proper solution of the problem. Experts can also take positive measures according to their own experience, so as to reduce or effectively prevent problems again.
Collaboration: Data Center experts and users and other IT members need to interact closely, which requires clear written and oral communication, and often leads to articles, guidebooks and other contents for IT staff and users. The development of agile software development paradigms, such as DevOps, also emphasizes the need for collaboration, and builds operational support for a continuous software development and release cycle.

Development process and trend of CRAC energy saving in air conditioning system of data center

evelopment of data center air conditioning system CRAC
With the development of the data center industry, the data center air conditioning technology is developing rapidly, which can be divided into three periods:

Early data center air conditioning system (1950-1970)
In the early stage, the machine room was built for a computer (large, medium and small), and there was no uniform standard, which was completely groping for construction.
Because there is no special rooms dedicated air-conditioning equipment, this is the room of air conditioning in the common civil air conditioning or use of the building air conditioning system cooling comfort air-conditioning equipment, however, the comfort air conditioning is designed according to the environmental conditions of people demand, not in order to process the data of heat load and heat load of cooling function only, no temperature control precision, no humidity control function, no strict dust control measures, no test indicators.
The following problems are encountered in the use of comfortable air conditioning in the machine room:
The comfort air conditioner can not keep the temperature of the machine room constant, which may lead to a greatly reduced life span of electronic components.
Unable to maintain the temperature uniformity of the machine room, the local environment can easily overheat, resulting in the sudden shutdown of the machine room electronic equipment.
Unable to control the humidity of the machine room, the humidity of the machine room is too high, which can lead to condensate water, which may cause a local short circuit of the microcircuit.
Low humidity in the machine room can produce damaging static electricity, resulting in abnormal operation of the equipment.
The lack of wind and filter effect, the cleanliness of the machine room is not enough, the accumulation of the dust will result in the difficulties in the heat dissipation of the electronic equipment, easy to overheat and corrosion.
The design selection of comfortable air conditioning is poor, which results in a large amount of air conditioning maintenance and short life span.
Development data center air conditioning system (1970-2000)
There is a machine room specially designed for computer system, with special cabinet (big, medium and small cabinet), and start to develop the standard, including the site selection, area, etc.
Rooms also from the common civil comfort air conditioning refrigeration and cooling, turning to adopt constant temperature and humidity room dedicated precision air conditioning, room dust removal using fresh air system and equipment room of positive pressure dust removal, so as to realize the data center are kept moderate constant, good clean air, a remote monitoring requirements, etc.
The special precision air conditioning of the machine room is very different from the traditional comfort air conditioning in the design, which is shown in the following aspects:
Large air volume, small enthalpy difference
Year-round refrigeration operation
Constant temperature and humidity control
There are various ways to send wind
High reliability
Innovation phase data center air conditioning system (2000 - present)
With the development of the Internet, the advent of informatization has gradually increased the demand for data centers.
Data centers are also gradually moving into various industries, and there are differences in understanding and requirements of data centers.
Generally think that enterprise data center is a cost center, data center leasing firms think data center is a profit center, the financial sector to the data center strict reliability, manufacturing data center for ease of use and the cost is very high.
A variety of different requirements promote the rapid development of data center industry and the generation of innovative solutions.
In the case of air supply innovation, from the next air supply to the air conditioning equipment near the power supply;
With the innovation of cold source, the application of natural cold source is becoming more and more popular.
Innovation of construction mode and modular scheme;
Industrial innovation, large-scale data center introduction of industrialization concept;
The innovation of all kinds of air-conditioning equipment, the energy efficiency, performance and control of the equipment are not the same as ten years ago.
The development trend of data center air conditioning system
In order to guarantee the high availability of the air conditioning system in the data center, in the design of air conditioning system, the usability, energy saving and dynamic cooling are the future development trends.
availability
Data centers require far more usability than commercial buildings, and air conditioning systems do the same.
At present, the requirements for usability are generally divided into grade A and B, which require redundant design of air conditioning system and emergency plan for failure.
The traditional distributed air-conditioning system is highly available, and the single unit will not affect the normal operation of the data center.
The centralized cold source system in large data center application brings more challenges to usability, and multiple nodes need to design redundant schemes that can be backed up.
Green energy saving
Along with the concept of green data center, the green data center with energy saving and environmental protection has become the construction and use of data center and the consensus of equipment suppliers.
In the low carbonization trend, the data center needs to do something;
The refrigeration system is a major power hog in the data center, accounting for 30% to 45% of the total energy consumption of the whole system, and the energy saving of the refrigeration system has received unprecedented attention.
Optimization of air supply, cold and heat channel layout, isolation of cold and hot channels, intelligent group control and utilization of outdoor natural cold source have shown a phenomenon of blooming flowers and flowers.
There are also data centers that use heat recovery devices to generate hot water for use as a life, bath, swimming pool and other USES to reduce the carbon consumption of the entire system.
In terms of temperature and humidity setting, ASHRAE recommended temperature range in the 2011 version of 18 ℃ to 27 ℃, humidity range is recommended by more than 5.5 ℃ the dew point temperature, relative humidity is less than 60% relative humidity and dew point temperature of 15 ℃;
The relaxation requirement can reduce the energy consumption of the cooling, heating, humidification and dehumidification of the machine room while ensuring the normal operation of the machine room equipment, and reduce the energy consumption of the air conditioning system and the high energy consumption.
In terms of energy saving room air conditioning equipment, variable volume compressor, EC fan with high efficiency, energy-saving intelligent control, the application of the technology such as using natural cold source make the efficiency of computer room air conditioning unit and more flexible.
The attention to water has also gradually entered the field of vision, WUE, water consumption and circulating water application, and the application of rainwater is also valued in the design of data center.
dynamic
In the construction and application center of new data center, "on-demand refrigeration" or "dynamic refrigeration" also become an important evaluation criterion in data center cooling scheme.
The so-called "on-demand refrigeration" refers to the cooling output of air conditioning in the data center with the change of IT heat load, which is a dynamic and adjustable output.
As data center fever density increasing, data center air conditioning out to provide a stable, reliable, and green cooling at the same time, how to prevent the local hot spots have also become one of the need to consider the demand of cooling scheme.
The development of virtualization in data makes the heat of the server and other devices more volatile, including different time and different space changes.
The cooling temperature required for different IT equipment in the machine room is different, and even the cooling temperature of the same type equipment is different in different ages.
This correspondingly requires the refrigeration system to adapt to this trend, and can provide dynamic refrigeration schemes to meet the needs of different Spaces at different times.
Therefore, dynamic refrigeration is more suitable for virtualization requirements.
At present, the main applications of dynamic refrigeration are air volume intelligent adjustment (temperature control or static pressure control), variable capacity compressor technology, intelligent control system, etc.
The dynamic intelligent refrigeration technology is used to distinguish the cooling needs of different equipment in the data center.
Dynamic intelligent cooling technology by establishing multiple sensor group of sensors to monitor the temperature according to the heat dissipation demand in dynamic supply airflow, the air volume size can adjust at any time according to need, so as to achieve energy saving purpose.
The utilization rate of cold source is another important way to improve the cooling efficiency of data center.
In terms of air distribution optimization, from the initial large space natural air supply way, gradually upgrade to such as floor air supply, air duct air supply and some extensive way of organized supply air, and then to the current cabinet air supply or the operation of the closed channel cooling way, even more frontier for cabinets, chip, heat dissipation component cooling way of application.
High density
Unit power consumption increased as the data center, computer room calorific value more and more high, and high power density rack server, the application of the high-density devices such as blade servers, the cause of a single cabinet power continuously improve, a sharp rise in the heat of unit area, so the high density of room some problems emerged gradually.
After a lot of experimental verification, when the heat load of a single cabinet (server) is too high, the following problems can be solved by adopting the traditional air conditioning of the machine room.
The temperature control of the machine room is not ideal, there will be local "hot spot";
Because the equipment needs to take away so much heat through a large amount of circulating wind, the traditional air conditioning system will take up a lot of room space.
On the supply air duct units need to adopt the sectional area of size is very huge, overhead floor air supply unit under the height of the need to improve is to, cause is already running in the computer room will not be able to continue to use.
Therefore, the air-conditioning refrigeration system must be improved accordingly.
The high thermal density refrigeration system is an important part of the refrigeration system of the machine room.
At present, high density refrigeration, the application of more mature technology mainly has closed and cold hot channels, and the new technologies such as backplate cooling and chip cooling are the future development direction.
What's more, in the application of high heat flux, abandon the traditional way of convection and adopts thermal cooling method, such as the microchannel cooling technology, cold Plate (Clod Plate), the application of the cooling technology and so on.
In combination, the application of the elements related to free-cooling application, accurate delivery and fixed-point Cooling has become the hot spot and development direction of the current data center Cooling technology.