【 Weak current College 】 LIBR absorption chiller maintenance

Direct-fired LIBR absorption chiller not only gas and both refrigeration and heating. In recent years, this water chiller has been widely used. However, it is the biggest flaw feature every year 20% of the velocity and attenuation. In order to compensate for the deficiencies and to make the equipment often is in good condition, you must set professional maintenance. This article in Shanghai Jiaotong Kalee-bromide water chillers, for example, discusses lithium bromide unit maintenance and maintenance.
First, overview
Direct-fired LIBR absorption chiller for gas burning as a heat source, will be heating dilute solution of LIBR to boiling, separating out the refrigerant vapor and lithium bromide concentrated solutions, the refrigerant vapor through the condenser cooling into cold water, but of LIBR concentrated solutions back to the absorber, absorption from the evaporator of the refrigerant evaporating became dilute solution, thus continuously cycle refrigeration cycles. Direct-fired heating cycle that is heating the water is still produced by the evaporator, heat water, the unit of evaporating pumps and systems of cooling water pump stops running. Dilute solution through low temperature, high temperature heat exchanger after entering high-voltage generator, fuel combustion heating, steam generating refrigerant. The refrigerant vapor directly into the evaporator, the heat in copper tube flow of hot water, cooling itself is condensed into cold water and return to the absorption of, and high-voltage generator was concentrated in concentrated solutions also directly back to the absorber and mixed with water cooling agent, and return to the status of the dilute solution.
Direct-fired LIBR absorption chiller is mainly composed of high-voltage generator, low-voltage generator, condenser, evaporator, absorber, high-temperature heat exchanger, low-temperature heat exchanger, heat exchanger and shield pump, vacuum pumps, electrical cabinet, exhaust systems pipeline valves, etc. Its control system to a microcomputer-based control center used to monitor and control the operation of the machine, micro-computer according to actual needs, the command generates the appropriate host and heat quantity to meet the actual needs, while providing sophisticated security measures.
Second, the content of lithium bromide unit maintenance
To enable the LIBR absorption chiller for safe and reliable running and play the best results, the maintenance of the unit as follows:
1, to make lithium bromide unit air tightness test. Vacuum is LIBR conditioning of first life, such as the high vacuum, on the one hand makes the tank corrosion, shorten the life of the host; on the other hand refrigerant water or low temperature evaporation results in reduced cooling capacity, energy consumption increased, thus affecting the normal operation of the unit. Testing method is to machine the nitrogen filled cavity 0.12Mpa for leak detection test, seal parts, solution pumps, coolant pump, flange connections, welds, etc to leak, leak timely replacement or repair of leakage points. Host cavity pumping to high vacuum, 24-hour period if no change in atmospheric pressure, temperature, U-type vacuum tables should be no change.
2. lithium bromide unit solution regeneration treatment: If the machine gives off solution opacity, color from gold to green or black anhong, when you use the precipitation and filtering method to remove the impurities in solution, to clarify, and measure the chromic acid lithium, Lithium hydroxide, concentration and PH value, adjusted to the required range, the filtered solution should be stored in sealed containers. If the solution quality, corrosion occurs inside, especially the pitting corrosion, generate significant precipitation, corrosion and produce hydrogen, resulting in a vicious circle of refrigeration host vacuum output decline. As a result of corrosion of precipitation, solution heat exchanger performance. Corrosive substances in solution is suspended, with the solution in the system cycle can clog the host solution and refrigerant water infusion devices, copper ions will increase, causing coated copper. Canned motor pump bearing wear, damage shield pump. Corrosion in severe host also appears refrigerant contamination phenomena, a serious lack of refrigeration output, host does not run correctly. Copper ions in solution increases the physical changes caused by solution, performance degradation caused by the host.
3. lithium bromide unit of condenser, generator, absorber, evaporator is made from copper control. Due to the hazardous substances in water, corrosion and scale will precipitate, seriously affect the spread of cold, heat transfer efficiency. Maintenance for mechanical or chemical cleaning methods. To prevent copper coils, should avoid 0 ℃ below maintenance unit. In general each year 3-4 month on unit maintenance. In the event of malfunction, repairs and winter unit must first be water cover water (condenser, generator, absorber, evaporator) and pipe and heat exchanger in the water on the net.
4. inspection or replacement of wearing parts. If shield pump of graphite bearings, the sealing ring and diaphragm valves, diaphragm vacuum pump valve, y strainer, take apart and wash, junk removal, etc. If not timely to take apart and wash y filter, will cause the model y filter internal accumulation of refuse, blocking pipes, water impeded, refrigeration or heating efficiency.
5. safety accessories equipment calibration, sensor movement sensor performance measurement. Main: pressure gauge, pressure switch, temperature sensors, magnetic switches, relays, timers, etc. If no such security attachment devices action checksum performance measurement, the operator was unable to determine a variety of technical indicators that will cause accidents or does not meet the functional requirements.
6, burner check filters, electrode, nozzles, clear the furnace dust, set electric batons detection or replaced. If not timely adjustment nozzle with a clean nozzle of carbon, will cause the fuel supply is insufficient or inadequate combustion, reduced fuel effect.
Third, a Hall, lithium bromide unit and related system maintenance instance
A Hall with two models for 16DF028 of LIBR absorption chiller. The Unit May 2002 the official run, according to the unit using instructions basically every two years a large maintenance. In April 2005 for refrigeration heating effect is not evident, the energy consumption of our lithium bromide unit, refrigeration, cooling water system, cooling system equipment maintenance, made the following technologies:
1, on two LIBR absorption chiller for maintenance
1) on the unit heat transfer tubes: absorber, condenser, evaporator for cleaning. Cleaning of heat transfer in a copper pipe, we start using the traditional mechanical cleaning methods, but we found that copper tube has the scale, and chemical cleaning method except net scale.
1, 2)Unit for regeneration of lithium bromide solution. The instrument, solution concentration does not meet the standard, the decision to add lithium bromide (55%) solution 300 kg, chromic acid, lithium 2.5 kg 2.5 kilograms of Lithium hydroxide, Octyl 13 kg.
3) replace the water Chamber seal, replace the valve plate and filling pressure testing, leak detection 0.12Mpa nitrogen and holding pressure after passing true air tightness pumping.
4) on the burner furnace dust, carbon and adjust the nozzle in addition, the replacement of asbestos nozzles and porcelain set 15 only.
5) check electrical control loop, sensors, thermometers and adjust the parameter unit commissioning, normal refrigeration, heating.
6) unit is run, the engine room environment temperature high (40-50 ° c), a lot of energy wasted, equipment components vulnerability, employee actions sweat, conducted on lithium bromide unit aluminium silicate mineral wool insulation, saving energy, ensure that theunit operation, improve the working environment.
2. on the frozen water, cooling water system piping water treatment maintenance
Inspection found that the frozen water, cooling water systems, water becomes cloudy, blackening, into and out of the water of the large temperature difference exceeds the normal range. Description of the pipeline in the pipeline corrosion in fungi, algae, scaling, the pipeline turned fine, running smoothly.
LIBR absorption chiller is the water as the medium of doing work, due to the frozen water, cooling water in the system long stay, even very minor corrosion, its corrosion products will also accumulate in the system, the pipeline scaling, rot, shorten the life of the pipeline and affects the transmission cooling, heat transfer efficiency. So we chilled water, cooling water system for chemical water treatment, that is, on this system for sterilization, chemical cleaning, coating and maintenance to function properly.
3, in the air conditioning system operating in the normal operation of cooling tower is also very important. There is a Hall, 250t/h cooling tower 5, installed in 70 m the highest, because it is open open, sand, dust easily in the deposition of cooling tower, causing no gaps between the filler, not heat, the cooling water temperature is too high, causing the unit outages. In March we had a run of cooling tower for the first time since maintenance, electrical control circuits, electrical, thermal packing, water Distributor, stagnant water plate, bracket adjustment, maintenance, cultivation and water quality testing, speed up the cooling speed, preventing a cooling tower water floating inside, making it the best State.
To sum up, equipment maintenance to ensure the normal operation of the main equipment. Equipment maintenance work, timely processing of all the problems occurring at any time, improve equipment operating conditions, will be able to take precautionary measures to avoid undue losses, maximize equipment efficiency and energy conservation. By lithium bromide unit maintenance practice has proved that the life-saving equipment and determine to a large extent on the degree of maintenance.