【 Weak current College 】 Central air conditioning and heat pump and heat source programme on

Summary: cold (hot) source source whether or not directly related to building the economy air conditioning of investment and operating costs. This article in the actual design of the programme, for example, on different refrigerator cold source and heat pump heat source programme carried out comprehensive comparative economic analysis, and thus concluded that the use of "heat pump" Tower of heat source system for air conditioning and heating and sanitary hot water supply, it is an economic rational of the programme.

Heat source for heat pump summer Tower high water evaporative cooling heat recovery refrigerator, can provide the hotel with free hot water and sauna hot water; excessive seasonal produce sanitary hot water when the cooling capacity available for dining, entertainment and function room air conditioner free of use; in winter the low-grade heat pump, heat from efficient broadband frost-free heat source system, you can effectively protect the heat pump for heating and sanitary hot water needs of low-grade heat source.

In the absence of boiler and other auxiliary heat source, heat Tower heat pump stand up to the South of the fiftieth year spell test, indoor heating temperature reached 30 ° c to 45 ° c above the hot water. System operation and reliable maintenance of small, this does not need to design for boilers, water and underground pipe auxiliary heat source system for heat pumps, investment and economic reasonable, indoor and outdoor machinery equipment footprint are relatively small, energy-saving effect is clear, as well as the impact on the surrounding environment in line with the national environmental standard for air conditioning cold (hot) source source, it is worth exploring and sharing.

Keywords: heat, cold (heat) source heat pump, heat Tower

1. project profile

Tonglu hotel is located in the Centre of urban development — — Hangzhou Tonglu County. Tonglu hotel is a four-star standard design Assembly rooms,dining, entertainment, leisure, conferences, Office and shopping centre as one multi-functional integrated projects. Above ground area: 34210m2. underground area: 3160m2. summer cooling load is 2500KW, winter heating load to 2000KW. the unit area cold indicators 70.4W/heat per unit area m2. indicators for 58.5W/m2. hot water load to 5000KW/day.

2. different cold (heat), heat pump programme compared to the initial investment

2.1 mixed source heat pump cold (hot) source and initial investment

System performance in the southern region of refrigeration load greater than heating + hot load of 20%, in order to maintain underground soil temperature balance, achieve economic operations, design uses mixed source (buried pipe + cooling tower) ground source heat pump. Underground soil source can be maintained at a temperature of 16-22 ¡æ, the average temperature of the heat pump, heat remains 12 ~ 6 ℃. The heat pump is 15 ° c heat source as the quantity of heat, the temperature in heat 12 ~ 6 ºc operation heating although attenuated, but you can still meet your heating and hot water load 2500KW the demand. Heat pump heating performance coefficient COP value 3.5 above, principally relied on expensive cost to source a foil for buried systems, to achieve a single run economic indicators of efficiency.

The early investment in the near future the system originally SaaS has source embedded pipe drilling teams to Liuyang city Villa do to source buried pipe, rock drilling depth of 35 meters, single rig rijin ft depth only 10 m, depth cost in excess of $ 100/m. In large buildings with nervous, the single depth can reach 80 ~ 100 m as well depth increasing rock hardness will be higher, well depth cost is 120 ~ 200 Yuan/meters (demonstration project of Sichuan ground source heat pumps). Use of mixed-source heat pump unit and cold (heat) in the source at the beginning of the buried system 710.00 million investment.

2.2 air source heat pump cold (hot) source and initial investment

System performance summer refrigeration, air-source heat pump cooling efficiency and outdoor climate has a direct relationship with the outdoor temperature, unit power with outdoor environment temperature. Air temperature 35 ° c water temperature 7 ° c, air source heat pump refrigeration EER EER values around 2.5. Winter heating, South-East from specific geological and climatic factors, become cold and warm air confrontation zone "at low temperature and high humidity," air-low grade "latent" content is high, air-source heat pumps for structural defects, cannot effectively use low-grade heat source, the cumulative duration of approximately 50 days (-5-2 ° c temperature nearly 10 days or so, 2 to 5 ° c temperature nearly 40 days or so). When the air-source heat pumps as wind speed 2 m/S, outdoor air dry-bulb temperature from 0 to 5 ° c, relative humidity 80% > is the most severe frost, the average of once per hour, according to the modern technology of frost without stopping the by-pass reversing a defrosting process, defrosting time not less than 8 minutes (including indoor reverse heat). Air source heat pump 0 ~ 5 ºc in a cream to a half of full cream and frosting, heating performance 35 ~ 40% reduction in heating defrosting it amounted to about 15 ~ 20%. Therefore, in the worst condition air source heat pump unit of actual heating output, only the standard conditions for quantity of heat at around 50%, heating performance coefficient average only about 1.5 COP.

Design uses standard refrigeration capacity to 3800KW air source heat pump unit and auxiliary electric heating appliance 500KW, able to satisfy the most unfavourable conditions for heating heating. According to scroll compressor construction does not adapt to the air-source heat pump frosting, long-running at high differential pressure, easily damaged and other factors, should adopt screw compressor, air source heat pump programme of initial investment to host 716.00 million.

2.3 heat Tower heat pump cold (hot) source and initial investment

2.3.1 source Tower heat pump principle

Heat source column defined as heat pump: summer for efficient water evaporative cooling refrigerator, winter frost free broadband for efficient air-source heat pumps.

Heat pumps are elevated and low grade energy from sources of heat, heat pumps necessary in smaller heat temperature difference of running to get higher heating performance factor, according to the actual condition of heat source Tower design heat pump operation, so as a heat source tower with heat pump.

Heat source Tower heat pump works: from the heat source Tower swirl fan disturbance environment "low temperature and high humidity" air from the bottom of the Tower, the low temperature at the bottom of the broadband heat exchanger aweather reverse circulation, the formation of heat transfer surface and ambient air between sensible heat and latent heat exchange. Broadband exchanger small temperature difference from heat pump evaporator temperature cycle solution (glycol dilute solution) from the upper band heat exchanger into the bottom out of the liquid, the liquid below ambient temperature 2 to 3 ° c, solution as a heat source tower with heat pump low temperature level the heat source.

Natural frost-free operating period: Southern winter, environment temperature for 2 to 5 degrees centigrade of duration is 40 days, the winter weather-temperature and high humidity is above 85% traditional narrowband air source heat pump condensation rate relatively frequently. Closed-source Tower because of the design adopted the freezer-15 ℃ temperature broadband small temperature difference heat transfer technology, than the traditional narrowband air source heat pump condensation temperature has fallen by 5 ~ 6 ° c, 85% probability of frosting. Ambient air temperature is higher than the above 2.0, air relative humidity large latent heat content, broadband heat exchanger in a large quantity of heat, while condensate condensation drain condensate separation system automatically.

Artificial frost-free operating period: Southern winter, ambient air temperature is below 1.0 ¡æ below the cumulative amount of time for about 10 days or so, in order to prevent negative temperature heat and humidity of air (low broadband heat exchanger) frosting, negative temperature spray equipment according to the intelligent control, automatic spray green antifreeze solution (selection of the food industry with non-toxic, non-corrosive and antifreeze) reduce heat exchanger surface freezing point, low-temperature period using concentration unit separation water.

Heat source Tower heat pump programme after careful consideration of scientific proof, concludes a cross between water cooling refrigerator energy-saving and frost-free air-source heat pump combination between refrigeration and heat pump systems. Through various research and online market research to understand the source of the heat pump can Tower effectively solved groundwater heat pump without water, ground source heat pump cost high soil, the traditional summer air-source heat pumps, refrigeration and heating energy consumption of high-finned heat exchangers easy frosting lower heat transfer efficiency, defrosting problems such as energy consumption, resulting in the heating energy consumption is high. Heat source for heat pump summer Tower high water evaporative cooling refrigerator, winter frost free broadband for efficient air-source heat pumps, stand up to the South of the fiftieth year spell test, room heating temperature reached 30 ° c to 45 ° c above, the hot water. Heat source heat pump cooling tower, warm air conditioning and hot water supply machine three use without auxiliary heat source, energy saving and environmental protection, efficient, and initial investment is reasonable, the heat source tower with heat pump cold (hot) source system cost 445.00 million, compared to other heat pump programme are as follows:

① contrast mixed source heat pump programme reduced initial investment decreased 265.35 year repayment interest 27.76 million, energy consumption increased 5.85 million, the actual ratio of mixed-source heat pump programme, reducing the cost of 21.91 million.

② contrast air-source heat pump programme reduced initial investment 271.65 million. Reduce the years of repaying interest 28.41 million, the Festival energy consumption reduction 71.27 million, the actual ratio of air-source heat pump programme, reducing the cost of 99.68 million.

Conclusions of the

Through the different heat pump and cooling (heat) source system programme integrated economic analysis is not difficult to see that the Tower of the heat pump cold heat (thermal) source system as large and medium-sized buildings (particularly with hotel services) central air conditioning system, cold (heat) source has obvious low initial investment, energy and stable performance. From regional geology and natural environment, in a climate of appropriate areas south of the Yangtze River in winter and summer season with excessive, eliminates the boiler equipment, water and underground pipes and other secondary cold (hot) the source system, consistent with the geographical situation in southern China. A machine with three available, equipment utilization rate is high.

Heat source summer cooling tower with heat pump than cooling tower better cooling effect, lower wind speed satisfactory reduces noise; winter heat tower with broadband small temperature difference heat transfer design that draws on low-grade heat capacity than narrowband air source heat exchanger temperature drop frost 5 ~ 6 ° c, 85% probability of frosting. In the environment and the negative temperature during run time, the design of the spray frost system and whirlpool steam-liquid separation noise canceling system, effective control of environmental pollution.

Heat source heat pump system throughout the tower can be better than a mixed-source heat pump system, integrated operating cost savings 11.6%, reducing the initial investment 265.35 Yuan; annual savings than air-source heat pump integrated operating costs 61%, reducing the initial investment 271.65 million. Therefore, heat Tower heat pump system in climate suitable areas south of the Yangtze River Valley medium sized buildings can be widely used.