【 Weak current College 】 water source heat pump technology concept features and working principle describes

Summary: this article first introduces the concept of a water source heat pump technology and works, along with boiler and air source heat pump energy utilization perspective have done a comparative, water source heat pump technology is the use of renewable energy technology. Subsequently, detailed description of the characteristics of the water source heat pump and introduced to the source application and abroad on the basic situation and China's current development and application of water-source heat pump, finally, the prospect of a special describes Tsinghua tongfang water source heat pump technology features and China water source heat pump application questions.

First, water source heat pump technology concepts and working principle

Water source heat pump technology is the use of shallow water on the Earth's surface, such as groundwater, rivers and lakes in the absorption of solar and geothermal energy and formed by low temperature heat energy resources and the principle of using heat pumps, through a small number of high energy input, low heat energy to high heat transfer of technology.

The Earth's surface in shallow water sources such as depth of 1000 meters of ground water, surface of rivers and lakes and oceans, the absorption of the Sun enters the Earth's radiant energy and water temperatures are generally very stable. Water source heat pump unit works is in the summer heat in the building to the water, because water temperature low, so you can go high zone, while in winter, the heat is extracted from the water, energy and heat pump principle by air or water as refrigerant elevated temperature evacuation to the building. Usually water source heat pumps consume energy, 1kW users can get more than heat 4kW or cold.

Water source heat pump based on water use, can be divided into a closed system and two open system. Closed system means the water side as a set of closed-loop heat pipe, casing general horizontal or vertical buried or lake water, and soil or water heat exchanger to achieve the energy transfer. (Where buried in the soil system also known as the buried in the ground-source heat pump, seawater system also known as sea water source heat pumps). Open system is measured from the surface water, ground water or heat exchangers after the direct discharge of the system.

And boiler (electricity, fuel) and air-source heat pump for heating systems, water source heat pumps have a distinct advantage. Boiler heating only 90%-98% of the power or 70 ~ 90% of the fuel energy into heat, available to users, so the ground source heat pump than electric boiler heating savings of more than two thirds of the energy savings than fuel boiler half of energy; as the water source heat pump heat temperature year-round more stable, generally 10 to 25 degrees centigrade, refrigeration, heating coefficient 3.5 ~ 4.4, and compared with traditional air-source heat pump, up to 40 percent, its running cost for General conditioning of 50-60%. Therefore, in the last decade, especially in the last five years, water source heat pump system in North America such as the United States, Canada and Switzerland and the Nordic as, Sweden and other countries made a rapid development, China's water-source heat pump market are becoming increasingly active, you can expect that this technology will become the 21st century most effective heating and cooling and air conditioning technology.

In traditional Chinese concept of air conditioning systems, because of the country's economic development and policy influence, in a rather long period, to the North in General resolved-fired boilers for heating in winter, in the South to cold water unit to solve the problem of summer cooling. In the 1980s, the refrigeration unit began to diversify, at this point, the emergence of lithium bromide unit, forced-air cooling unit, unit capacity is from the original-sized turbine transition to large unit, in the 1990s, for heating way began to try new things and explore in the wake of sustainable development and public awareness-raising, the world and China energy structure is changing, from the original coal, oil heating transition to natural gas and electricity, and other clean energy sources. Air pollution in Beijing as the most serious one, its governance, urban air pollution policies in respect of structural adjustment, including energy, mainly from coal to natural gas and electricity energy alternatives. However, alternative energy sources while part of the solution to the problem of air pollution, natural gas and oil, etc., are not renewable sources of energy, from the perspective of sustainable development, the need to improve energy efficiency or renewable energy seeking, water source heat pump unit is ideal for a device.

II. characteristics of water-source heat pump

Due to the water source heat pump technology using surface water for air conditioning unit refrigeration heating source, so it has the following advantages:

1. in the case of renewable energy technology

Water source heat pump is the use of the Earth water is stored solar energy resources as heat and cold sources, energy conversion of heating and air conditioning systems. Where you can take advantage of the water, including water or river, the surface of some rivers and lakes, and oceans. Surface soil and water is not only a huge solar collector, a collection of 47 per cent of the solar radiation energy, than the human use of energy per year up to 500 times more (ground water through the soil indirectly accept solar radiation energy), and is a huge dynamic energy balance system, the surface of the soil and water naturally maintain energy acceptance and divergence of relative equilibrium. This makes the use of stored in one of the almost infinite solar or geothermal energy. Therefore, water source heat pumps use the clean renewable energy technology.

2, high efficiency and energy saving

Water source heat pump unit available water temperature in winter is 12 ~ 22 ° c, water temperature, air temperature higher than, the heat pump cycle of evaporating temperature increases, the energy efficiency ratio also improved. While summer water-18 ~ 35 ° c, water temperature higher than ambient air temperature is low, therefore reducing refrigeration condensing temperature, cooling effect of better than-air cooled and cooling tower, generating efficiency. According to the United States Environmental Protection Agency EPA estimates, design and install a good water source heat pump, on average, you can save users 30-40 per cent of the running of the heating refrigeration and air conditioning.

3. run stable and reliable

Water temperature throughout the year is relatively stable, its scope is far less fluctuation of air change. Is a very good air conditioning with heat pump, heat and cold sources, water temperature is constantCharacteristics that make the heat pump unit operation more reliable and stable, but also ensures that the system's efficiency and economy. No air-source heat pumps winter defrosting and other difficult issues.

4. environmental benefits significantly

Water source heat pump uses power, power itself as a clean source of energy, but in power generation, consumption of primary energy and lead pollutants and carbon dioxide emissions of greenhouse gases. So the energy of the device itself is the small contamination. Design good water source heat pump unit of electricity consumption, and air-source heat pump is equivalent to less than 30 per cent, compared with electrical heating, equivalent to 70 percent. Water source heat pump technology adoption of R22 refrigerant, or R134A, R410A, R407C and substitute total quality, water source heat pump unit is run without any pollution, you can build in residential areas, there is no burning, no smoke, no waste, no need to dump fuel waste site, and no long distance transmission of heat.

5, multi-purpose a machine, a wide range of applications

Water source heat pump system for heating, air conditioning, also for hot water supply, multi-purpose a machine, a system can replace the original boiler plus air conditioning of two sets of equipment or systems. Especially for both heating and cooling requirements of the building, there is a clear water source heat pump. Not only saves a tremendous amount of energy, and use a set of devices can both heating and cooling requirements, reducing the initial investment of the device. Water source heat pump can be applied to hotels, shopping malls, office buildings, schools and other buildings, small water-source heat pump is more suitable for Villa residential heating and air conditioning.

6, automatic operation

Water source heat pump unit because the condition is stable, so you can design simple systems, parts, plant operation simple, reliable, low maintenance; a high degree of automatic control, long service life up to 15 years. Of course, like any thing, water source heat pump is not perfect, its application would also be affected by the restriction.

⑴, available water conditions

Water source heat pump is theoretically possible to make use of all water resources, in fact, in a real project, different water use of cost differences are considerable. Therefore, in the different regions of the availability of suitable water-source heat pump water source as a key part of the application. Current water heat pump uses, closed system generally cost more. And open system, the possibility of finding suitable water becomes the use restrictions of water-source heat pump. Off-system, water requirements must meet a certain temperature, water and cleanliness.

⑵, water geographical hierarchy restrictions

For use of underground water recharge, consideration must be given to the use of the geological structure, make sure that you can drill wells in economy find appropriate sources of water, at the same time should also consider the local geology and soil conditions, guarantee to use tail water recharge can achieve.

⑶, investment economics

Due to different users in different regions, and the national energy policy, fuel prices, the basic conditions of water; one-time investment and running costs with the user. Although in General, water source heat pump operation more efficient and less costly. But unlike traditional air conditioning heating way compared to the different needs in different areas of the economics of investing in water-source heat pump will vary.

III. domestic water heat pump for the development and characteristics

Abroad, study on water-source heat pump fall two heat pump systems: one for ground source heat pumps, a heat pump seawater. Which heat pump the true meaning of the commercial applications are nearly ten years of history, but the development is very fast. Such as the United States, as of 1985 National 14,000 Mesa heat pump, which is installed in 1997 45,000 units installed so far, but the 400,000 annually to 10 per cent of the rate steady growth. In 1998 the United States commercial building ground source heat pump system has accounted for the total population of air conditioners 19%, with new buildings account for 30 per cent. United States ground source heat pump industry was established by the United States energy and environmental research (Energy & EnvironmentalResearchCenter), the United States Federation of groundwater resources (NationalGroundWaterAssociation), Edison Electric Institute (EdisonElectricInstitute) and numerous ground-source heat pump manufacturing design marketing companies and Government agencies and contractors, 146 Member United States ground source heat pump Association, the Association in recent years will be invested US $ 100 million in the development, research and extension work. United States plan to achieve annual 2001 installed 40 million target platform, heat pump, water source heat pump 15 per cent, will reduce greenhouse gas emissions 1 million tons, equivalent to a reduction of half a million car emissions or kind of tree-planting 1 million acres, the annual saving energy costs up to $ 4.2, thereafter, the annual energy costs increase 1.7 billion.

United States water source heat pump manufacturers are famous companies have AddisonProductsCompany, AdvancedGeothermalTechnology, CarrierCorporation, ClimateMasterInc., EconarEnergySystemsCorporation, FHPManufacturing, MammothInc., TheTraneCompany, WaterFurnaceInternational etc. United States water source heat pump and applied more biased for residential and commercial small-scale system (20RT below) and the use of water-air systems, such as the well-known TRANE, launch products. In large buildings, the United States implemented the system, i.e. water ring WLHP heat pump system.

And the United States in the development of different ground-source heat pump, Central, and Northern Europe such as Sweden,Switzerland, Austria, Germany and other countries mainly use shallow geothermal resources, underground soil buried pipes (depth < 400 m deep) of ground source heat pump, used to indoor floor heating and providing hot water. According to a 1999 statistics for household heating appliances, the proportion of ground source heat pumps, Switzerland is 96%, 38%, Austria as a 27 per cent in Denmark. At the same time, the Nordic sea research and application of heat pump or more.

The earliest in the 1950s, in Shanghai, Tianjin and other places to get summer winter irrigation way extract groundwater cooling heat energy Research Institute, Tianjin University Professor Lu-Chan on our earliest heat pump, 1965, developed the first water-cooled heat pump air conditioner. At present, China's Tsinghua University and Tianjin University, Chongqing jianzhu University, Tianjin University, Guangzhou Institute of Chinese Academy of Sciences wait a number of universities and research institutions in research on water-source heat pump. One of Tsinghua University in multiple load water source heat pump after years of research has formed the fruits of industry, has completed a number of demonstration projects. Domestic water source heat pump manufacturer in Tsinghua tongfang artificial environment equipment company, Shandong Haiyang fuerda is earlier water source heat pump manufacturers, but also a considerable number of refrigeration and air conditioning manufacturers be ordinary cold water unit for water-source heat pump. China's water-source heat pump research and application has just started, compared with foreign countries, in heat pump design of optimization and engineering application also exists a large gap.

At present, the world particularly optimistic about China's market. United States Department of energy and the Ministry of science and technology in November 1997, signed the Sino-u.s. energy efficiency and renewable energy cooperation protocol, which is one of the main content of the "heat pump", the project is intended to be used in China, Beijing, Hangzhou and Guangzhou 3 cities with the building of a geothermal heat pump for heating and air conditioning business architecture to promote the use of such "green technology", alleviate China coal and oil dependence, so as to achieve the aim of diversification of energy resources. Allegedly "Hua Ting Garden" that is, the application of this project. 2000 June 19 to 23 November in Beijing by the Ministry of science and new technology development and industrialization of Division held a u.s. geothermal pump Technology Conference, the Conference theme is "the use of geothermal heat pump technologies provided to residential or public buildings heating refrigeration, significantly reducing the running cost of the energy saving solution" topic.

In the next few years, China is facing a huge energy pressure. On the one hand, China's economy to maintain a relatively high rate of growth, on the other hand, it must take account of environmental protection and sustainable development issues. So called energy efficiency, energy restructuring required. Energy efficiencies, and encourage a variety of energy-saving equipment and technologies, the direction of energy restructuring is primarily from coal to gas, until the conversion to electricity. In China's energy consumption, building energy consumption ratio is quite high. In order to adapt to market requirements and participate in international competition, we must speed up China's brand of water source heat pump industry in research and development.

Fourth, Tsinghua tongfang technical characteristics of water-source heat pump

Tsinghua tongfang development of water source heat pump unit is designed for large and medium-sized construction development can achieve module combination water-water heat pump unit. You can make use of ground water and water of the lakes and rivers as well as the geothermal water. On different water source, you can do with intermediate heat exchanger to constitute a closed or open system. Unit in the work of hot and cold water through the switch on the system of the switch and the implementation of the pipeline, fluoride system remains stable.

According to the study of the compressor and market forecasts, planning of water-source heat pump consists of 4 different sizes: GHP300, GHP500, GHP600, GHP1000. Which basic GHP300 and GHP500 module, 2 x compressor independent system and 3 independent system compressor, GHP600 and GHP100 as GHP300 and GHP500 combination. GHP300 in standards for groundwater heat heating condition, in standard 309KW groundwater refrigeration cycle cooling capacity as 265KW.

Tsinghua tongfang's water source in product design, use of the technology line is: the use of R22 refrigerant, mature made of heat-pump technology, taking into account the actual situation in China, focusing on high water temperature and the realization of wide operation temperature, select and determine the compressor working points and scope of work, in the spirit and energy saving ideas, design of large temperature difference of water heat exchanger. Fluoride system design uses subsystem fully independent modular concept system parts quantity and quality. Control system fully consider the coherence of the various system controls, and set a variety of security, taking water system water pump control and remote operation. Tsinghua tongfang's water-source heat pump in addition to the traditional water source heat pump all the features, as China's national conditions designed system, it is worth noting that features:

1, heating water temperature high

We offer water source heat pump in standard mode, you can ensure that the water temperature stabilized at 52 ° c during testing and the actual use, the user has done 56 ° c for running experiments. Provide high water temperature, can increase efficiency, reduce the Interior side of the device selection capacity, and that indoor thermal comfort.

2, water side and out of the water temperature, water conservation

When working in the unit, water-side access in winter water temperature difference is 7 ° c, while in summer the water temperature difference of access to 10 degrees centigrade. Different from the traditional 5 ℃ temperature design, you can save water 20%-50%, and correspondingly reduced intake (e.g. drilling wells and pumps run). The thought of Yen-Chi Sen timber industrial in 1997 's "China refrigeration and air-conditioning industry technology development status and prospects of argumentation.

3, system optimization, part of sophisticated and reliable

Through the optimization of the system and the combination of independent modules, the final unit system is quite simple and reliable, but refrigeration parts selection are industry quality sophisticated brand, ensuring reliable operation of the unit.

4, unit capacity is big, wide application

Unit design stand-alone minimumCapacity to 150KW heat, you can open or closed type system, you can use groundwater recharge by drilling wells, can also increase the intermediate heat exchanger use river water of the lake or the sea. You can even take advantage of geothermal water tail.

5. run simple, quiet

Due to the use of intelligent automation, unit of operation is simple, with efficient protective measures that units of muffling operation noise is no longer difficult to accept.

5. at present, China's water-source heat pump application problems

Water source heat pumps as a new type of refrigeration and heating way, from a technical point of view, especially in the heat pump's perspective should be fairly mature, no problem. But taking into account the situation of China, as well as water-source heat pump heating systems as a whole to promote the application, or there are some problems:

1. water use policy

In order to protect the limited water resources, developed the People's Republic of China, the city's water law have developed their own "urban water management organization. These policies are stressed water, water charges. And approval of standards for similar requirements for water-source heat pump technology does not provide, water source heat pump is very easy to be indicators of water use. Notwithstanding the approval by the water, because in some places the water taking and discharge twice by fees, the fees of the national standards without unity, so results may cause high water, water source heat pump operation costs less than the increase in water, water source heat pump economics become enquiries. Therefore, the promotion of water-source heat pump requires government from the perspective of sustainable development, environmental protection and resources integrated energy aspects into consideration, adjust the water source heat pump water policies, the need to redefine how management and water charges in order to promote the development of its mass.

2, water exploration mining technology and costs

In China, currently on the water, especially urban water detection technology should improve the application of the water source heat pump is one of the prerequisites must understand local water sources, water source heat pumps use of early, must be ground on the water situation, groundwater quantity if there is water, the water is sufficient, the venue is suitable for drilling wells and recharge. And detection of mining technology improves and costs lower, will promote water source heat pump unit of the better application.

3. groundwater recirculation technology

Water source heat pump to use groundwater, water recharge must be considered, for Reinjection Technology must be combined with local geological situation considerations, to consider recharging technology. We have different areas of geological structure know also, that also restricting the spread of water-source heat pump unit.

4. the overall system design

Water source heat pump system for energy conservation as a system, you must consider all aspects, if water source heat pump unit can take advantage of smaller water provides more energy, but the system design on the pump, and other energy-consuming equipment selection for improper or incorrect, will control reduce the system's energy saving effect. Similarly, if the unit offers high water temperature, but the design of the air-conditioning system of the Terminal is not to be appropriate to consider, and may cause the entire system of effect, or it makes the whole system of initial investment. Therefore, the application of water-source heat pump, need more various professional fields to come together to jointly support from government policies, host of design and manufacture, system design and management aspects of all participants.