2. Technical air conditioning; Also known as constant temperature and humidity air conditioning, indoor air temperature, humidity, airflow speed, cleanliness and other parameters are controlled within a certain range to meet the requirements of production technology.
3. Refrigeration capacity: the heat absorbed by the refrigerant on the low-pressure side in the evaporator per unit time when the air conditioner is in refrigeration operation. Commonly used units are w or KW.
4. Heat pump heating; When the air conditioner is operated with a heat pump (the auxiliary electric heater of the heat pump should be operated at the same time), the heat delivered to a closed space, room or area in a unit time.
5. Performance coefficient: The ratio of the amount of refrigeration (heat) generated in the refrigeration (heat) cycle to the power consumed by refrigeration (heat) is the performance coefficient. It is called the energy efficiency ratio when cooling, which is expressed by EER; It is called the coefficient of performance when heating, and is expressed by COP.
6. Refrigerant: Refrigerant is the working medium to complete the refrigeration cycle in the refrigeration system. The refrigerant absorbs the heat of the cooled object in the evaporator and evaporates, and transfers the heat to the surrounding air or water in the condenser and condenses into liquid. The refrigerator achieves the purpose of refrigeration by changing the state of refrigerant.
7. Refrigerant: Refrigerant refers to the intermediate medium used to transfer cold energy in indirect refrigeration system. After being cooled by the refrigerant in the evaporator, the refrigerant is sent to the cooling equipment for cooling to absorb the heat of the cooled object or environment, and then returns to the evaporator to be cooled by the refrigerant again, so as to achieve the purpose of continuous refrigeration.
8. Fan coil unit: it is a commonly used heat exchange device in central air conditioning system, and consists of finned tubes and fans. When the coolant flows through the fan-coil unit (inside the tube), it exchanges heat with the air inside the tube to cool the air. Fan coil unit is an air cooling unit.
9. Water-cooled chiller: Water-cooled chiller belongs to the refrigeration unit in the central air-conditioning system, and its refrigerant is water, which is called chiller. The cooling of condenser is realized by the heat exchange of normal temperature water, so it is called water-cooled chiller. The condenser of air-cooled chiller is called air-cooled chiller, and its cooling purpose is achieved by forced ventilation and heat exchange with indoor air. 5438+00, cooling tower; Special equipment for air cooling water is usually installed at the top of buildings. In refrigeration, electric power, chemical industry and many other industries. The hot cooling water discharged from the condenser and other equipment is cooled by the cooling tower and then recycled.
1 1, VRV system: short for VariablerefrigerantVolume system, that is, variable refrigerant flow system.
It is in the form of a group of outdoor machines, consisting of functional machines, constant speed machines and frequency converters.
By connecting outdoor units in parallel, the refrigeration pipeline is integrated into a pipeline system. According to the capacity matching of indoor units, the appropriate capacity of indoor units can be conveniently selected between 122.5 ~ 1.5 kw, that is, a group of outdoor units can connect up to 30 indoor units.
Indoor units include ceiling embedded, wall mounted, floor mounted, etc.
Different indoor independent machines can be connected to the refrigeration circuit and can be controlled independently.
The minimum capacity of the indoor unit is 0.6KW and the maximum capacity is 3.75KW. The capacity of the indoor unit can be adjusted within the range of 50% to 130% of the outdoor unit capacity.
12. Modular machine: It is developed on the basis of VRV system. 1985, invented by Jiefeng Group of Australia, applied for specialization.
It changes the traditional Freon pipeline into a waterway system, combines the indoor unit and outdoor unit into a refrigeration unit, and changes the indoor unit into a fan coil unit.
Using the heat exchange of cooling water to realize the refrigeration process, the modular machine is named because it can automatically adjust the number of starting units according to the requirements of cooling load and realize flexible combination.
13. Piston cooler; Piston chiller is an integrated refrigeration device that compactly integrates the piston refrigeration compressor, auxiliary equipment and accessories needed to realize refrigeration cycle, and is specially used for air conditioning and refrigeration purposes.
The refrigeration capacity of a single piston chiller is between 60 and 900 kW, which is suitable for medium-sized and non-engineering projects.
14. Screw chiller; Screw chiller is a large and medium-sized chilled water refrigeration equipment.
It is often used for air conditioning in national defense scientific research, energy development, transportation, hotels, restaurants, light industry, textiles and other departments, as well as chilled water for water conservancy and electric power engineering.
Screw chiller is a complete refrigeration system consisting of screw refrigeration compressor unit, condenser, evaporator, automatic control elements and instruments.
It has the advantages of compact structure, small volume, light weight, small floor space, convenient maintenance and stable operation, so it has been widely used.
Its refrigeration capacity ranges from 150 to 2200KW, which is suitable for medium and large projects.
15. Centrifugal water chiller; It is an integral water chiller composed of centrifugal refrigeration compressor, evaporator, condenser, throttle control device and electric meter.
The cooling capacity of a single machine ranges from 700 to 4200KW.
It is suitable for large and super-large projects.
16. lithium bromide absorption refrigerator: it uses heat energy as power, water as refrigerant, lithium bromide solution as absorbent, and refrigerant water above 0℃ can be used as cold source for air conditioning or production process.
Lithium bromide absorption type is driven by thermal energy, and there are three common types: direct combustion type, steam type and hot water type. Its cooling capacity ranges from 230 to 5800KW, which is suitable for medium-sized, large-scale and extra-large projects.
Several leading technologies in domestic central air conditioning industry
Leading technology of waste heat recovery
Heat recovery technology is a mature and advanced energy-saving and environmental protection technology in HVAC field, which can recover waste heat to the maximum extent, save electricity for units and provide domestic hot water for free; It is economical to directly reduce the emission of waste heat into the atmosphere, especially for the southern region.
At present, Tsinghua Tongfang has successfully applied heat recovery technology to air-source heat pump units and water-cooled chillers.
At present, the water source heat pump units produced and sold at home and abroad are mostly dry systems and all-liquid systems.
The energy efficiency ratio of dry system is relatively low, while the full-liquid system has some shortcomings such as difficulty in liquid level control and oil return.
Falling film system combines the advantages of dry and full liquid systems, which is not only high in efficiency, but also more stable and reliable by applying a new pressure difference oil return method.
The falling film heat recovery water source heat pump technology uses the falling film evaporator to realize efficient operation, which requires less refrigerant charge than the all-liquid unit and has less impact on the environment. Double-tube shell-and-tube condenser is used to realize cooling and recover condensation waste heat for domestic hot water.
The traditional method is to use double heat exchangers in series and parallel, or to realize it in an engineering system.
The double heat exchanger system has complex control and poor reliability; The recycled hot water realized by the engineering system has low grade.
This project adopts double tube bundle heat exchanger to realize heat recovery, which overcomes the above shortcomings.
The double-tube shell-and-tube condenser is adopted to ensure that the cooling water and the recovered domestic hot water run independently, switch freely, and do not pollute each other, thus perfectly realizing the function of total heat recovery.
Falling film evaporator is used to improve the operation efficiency and maintenance performance of the unit.
The refrigeration performance coefficient (energy efficiency ratio) is improved; The heat exchange performance of the evaporator is improved and the material cost is reduced; The temperature difference of falling film evaporator is small, which can appropriately increase the temperature difference of water, thus reducing the groundwater flow and the power consumption of water pump.
Convenient maintenance: refrigerant water flows in the pipeline, and the dirt on the water side can be cleaned by opening the end cover; The refrigerant charge is small, which is more in line with environmental protection requirements.
The intermittent differential pressure oil return scheme is simple and reliable.
The new differential pressure oil return scheme: when receiving oil, the high pressure solenoid valve is closed, the pressure balance solenoid valve is opened, and the oil flows from the evaporator to the oil collector through the one-way valve.
When returning oil, the pressure balance solenoid valve is closed, the high pressure solenoid valve is opened, and the oil pressure returns to the compressor from the high pressure.
Intermittent oil return is realized by controlling the action of solenoid valve through time relay.
Tested by Hefei Mechanical and Electrical Products Testing Institute, the nominal refrigeration energy efficiency ratio of Tongfang Ren Huan falling film total heat recovery water source heat pump unit reached 5.97, which was 30% higher than the national standard (≥4.60). The comprehensive energy efficiency ratio of refrigeration heat recovery operation (defined as the ratio of the sum of refrigeration capacity and heating capacity to power) reaches 7.09; The nominal energy efficiency ratio of heating reaches 4.72, which is 3 1% higher than the national standard (≥3.60).
At the same time, the performance of the unit has reached the requirements of the energy-saving unit in the Technical Requirements for the Certification of Energy-saving Products of Water-source Heat Pump Units specified by the Award-winning Certification Center, and reached the technical parameters of the Water-source Heat Pump Units in the Eleventh Five-Year Plan period proposed by the National Development and Reform Commission, and the performance of the unit has reached the world-class level.
At present, this technology has applied for a national patent.
The successful research and development of this technology conforms to the development trend of "energy saving and environmental protection" in the world air conditioning field, and also conforms to the call of national energy saving and emission reduction, which has high economic benefits and far-reaching social benefits.
Tsinghua Tongfang Central Air Conditioning Low Ambient Temperature Air Source System
Tongfang low-temperature air source heat pump technology adopts the world's leading patented technology of supplementing air and increasing enthalpy-using a compressor with an auxiliary air inlet to realize "quasi-two-stage compression" (that is, an economizer system), so as to improve the economic performance of the heat pump system, thereby improving the energy efficiency ratio of the heat pump system under low-temperature working conditions and solving the problem of efficient heating of the heat pump unit at low ambient temperature.
The bidirectional flash supercooling technology is adopted to realize bidirectional air supply for refrigeration and heating, which not only improves the refrigeration cycle performance, but also greatly improves the heating performance.
We have adopted the world-leading four-zone frost control technology unique to Tongfang-the four-zone frost control technology is a set of world-leading intelligent dynamic frost control technology unique to Tongfang, which is summed up through a lot of practical experience, to ensure the long-term stable operation of the air source heat pump unit at low temperature.
According to the outdoor environment and multiple information collection of the unit, comprehensive analysis and calculation are carried out; Different variable parameters are set according to different environmental temperatures, and different defrosting modes are carried out to ensure the accuracy of defrosting; The problems of accidental defrosting, long defrosting time, frequent defrosting and no defrosting are avoided to the greatest extent.
Through the application of the above technology, the low-temperature air source heat pump unit can work normally at the ambient temperature above -20℃, and at the same time solve the problems of low heating capacity and low energy efficiency ratio at low temperature.
High-efficiency All-liquid Ground Source Heat Pump Technology of Tsinghua Tongfang Central Air Conditioning for Supplementing Air and Increasing Enthalpy
Ground source heat pump (GSHP) is an environment-friendly air conditioning system that uses shallow underground geothermal resources for heating and cooling. It is an economical and effective energy-saving technology using renewable energy. Based on the present situation, the company decided to develop an "efficient all-liquid ground source heat pump unit" with high efficiency, environmental protection, energy saving and reliable performance.
Tongfang Ren Huan optimized the design of the unit according to the ground source conditions, and adopted all-liquid evaporation and economizer circulation system technology to improve the energy efficiency of the unit.
According to the overall process structure layout of the plant, a two-stage external (or internal) oil separator is set up, which not only improves the oil separation effect, but also reduces the resistance loss in the oil separation process.
By arranging the oil pan in the evaporator, the lubricating oil is led back to the compressor by using the principle of pressure difference, and continuous oil return is realized.
By controlling the superheat of evaporator return air and electronic expansion valve, the liquid supply and liquid level are accurately controlled, so that the system runs stably and efficiently.
Through the design of the gas collection device in the evaporator, the gas on the evaporation liquid level flows evenly and the evaporation pressure is balanced, which further stabilizes the liquid level in the evaporator and is beneficial to the stable operation of the system.
The integrated application of these technologies in all-liquid ground source heat pump system has not been reported at home and abroad.
Tested by Hefei Mechanical and Electrical Products Testing Institute, the nominal refrigeration energy efficiency ratio of Tongfang Ren Huan high-efficiency flooded ground source heat pump unit reached 5.66, which was 29% higher than the national standard (≥4.40). The nominal energy efficiency ratio of heating reaches 3.24, which is 4.5% higher than the national standard (≥3. 10).
The refrigeration performance index has reached the "Eleventh Five-Year Plan" target.
Developing energy-saving ground source heat pump products is helpful to the development of environmental protection and energy conservation in China, especially in the fields of building energy conservation, emission reduction and pollution control.
This product meets the requirements of building a circular economy and a conservation-oriented society and is an effective way to utilize renewable energy on a large scale.
The industrialization of this product, for our enterprise itself, will generate new profit growth points and realize a substantial increase in operating income.
The popularization of this technology will certainly promote the development of the whole refrigeration and air conditioning industry and contribute to the social and economic construction of China.
Tsinghua Tongfang Central Air Conditioning Heat Pump Technology-Air Source
Heat pump technology:
Heat pump is a kind of equipment that obtains low-grade heat from natural air, water or soil, and outputs usable high-grade heat energy through electricity, which can convert the consumed electricity into three times or more heat energy. It is an efficient energy supply technology.
The application of heat pump technology in air conditioning field can be divided into three categories: air source heat pump, water source heat pump and ground source heat pump.
Because heat pump extracts energy from nature, it has high efficiency and no pollutant discharge, and it is the cleanest and most economical energy way today.
In today's increasingly scarce resources, heat pump technology, as the most advanced way for human beings to use low-temperature heat energy, has been widely concerned and valued around the world.
Tsinghua Tongfang is the first enterprise in China to apply heat pump technology to air conditioning. With mature technology research and development capabilities in this field, we have successively developed four series of heat pump products: air source heat pump, water source heat pump, ground source heat pump and heat pump water heater, and deepened the technology and types of products according to the climatic conditions and resource conditions in different regions, and obtained more than 0/00 patented technologies.
Tsinghua Tongfang has become a leader in the field of heat pump central air conditioning.
Tsinghua Tongfang Central Air Conditioning Air Source Heat Pump;
The air source heat pump uses the infinite energy contained in the air to flow the indoor heat to the outdoor with higher temperature in summer, thus refrigerating the indoor; In winter, the heat in the outdoor air can be used to provide heat to keep the room warm.
Because the real cooling and heating heat of this central air conditioner comes from outdoor air and no cooling water system is needed in summer, it is very economical in operation cost and can save a lot of water resources. At the same time, the system does not produce any pollutants when it works, which is very in line with the trend and policy of energy conservation and environmental protection in China.
But for a long time, ordinary air source heat pump central air conditioning can only be applied in the middle and lower reaches of the Yangtze River, southwest and south China, and it can't work normally in the northern region in winter.
From 65438 to 0996, Tsinghua Tongfang improved the first generation air source heat pump technology. The unique technology of "supercooling and ice suppression" effectively solves the problem of incomplete defrosting, and makes it successfully applied to the Yangtze River basin and the Yellow River basin with the lowest temperature of -8℃ in winter.
After five years of painstaking research, Tsinghua Tongfang fully tapped the potential of the heat pump system, and once again launched the only low-temperature air source heat pump unit in the world to achieve -22℃ heating. The first application of air source heat pump in North China has completely changed the long-term history of using coal and gas for heating in North China, and played a positive role in improving the environment and saving energy.