Do you know the application of assembled plate heat exchanger in radiant cooling and heating?
Do you know the application of assembled plate heat exchanger in radiant cooling and heating?
Radiant heating and air conditioning systems in Europe and North America for many years and the use of history, different from the traditional convection type air conditioning system, radiant heating and air conditioning system, the radiation heat transfer accounts for the total amount of heat exchange of the 50% air conditioning system belongs to the low temperature radiation heat transfer, its working principle is to end radiation in summer enter the water at about 18, the formation of cold radiation; winter to provide radiation at the end of 45 degrees Celsius hot water, the formation of thermal radiation, thermal radiation and surface radiation on human body, and the rest of the furniture envelope surface exchange for cooling (heating). If the hot and cold water temperature is too low or too high to provide heating and cooling, can not meet the requirements of the end of radiation temperature, heat exchanger or other commonly used methods (such as water etc.) the cold (hot) medium water temperature reaches the design requirements of the system.
Application of radiant cooling
Radiation cooling, radiation in the end water temperature should not be too low, otherwise easy to produce condensed water in the radiation at the surface, resulting in condensation. Usually, methods used to control the end of the cold water inlet temperature of the radiation, the radiation plate surface temperature is higher than the dew point temperature 1 ~ 2 degrees, in order to prevent the condensation temperature of chilled water cooling system. The use of radiation the (16 to 18 DEG C) is usually higher than the conventional air conditioning system (7 C), 6-8 provides the option to use cold water high temperature evaporation cooling natural cooling source, but also makes the water chiller produced by a conventional freezing water (water supply and return temperature is 7/12 DEG C) cannot meet the radiant cooling system of the cold water temperature requirements, usually can be used to get the mixing method for high temperature radiation cooling is required, but in order to prevent the cold water directly into the heat (especially after the end of the capillary) in the heat exchanger The surface scale and the plug can be used efficiently in cold water chiller heat exchanger will produce the countercurrent heat exchanger and into sensible heat. At the end of radiant cooling heat at the end of the commonly used imported water temperature is 16 to 18 degrees centigrade, water temperature is 21 to 23 DEG C.
Application in radiant heating
In the application of low temperature radiant heating heat exchanger divided the water water heat condition and steam water heat condition 2. When steam is used as heat source, steam should be used in low pressure saturated steam, commonly used in Engineering: 0.3MPa pressure gauge or gauge 0.4MPa, the steam temperature is 144 DEG C and respectively. 152 degrees. When using hot water as the heat source, the hot water supply and return water temperature of 95/70 DEG C. Radiant heating, hot water supply at the end of the radiation temperature is not too high, generally not more than 60 DEG C, the main reason is that:
1, due to the larger radiation area, the water temperature is not too high to meet the design requirements at room temperature;
2, human comfort requirements of the ground temperature can not be too high;
3, high temperature, radiation heating of commonly used plastic pipe greatly reduces life expectancy. According to the different requirements of building insulation and the occupants, the ground temperature is usually controlled at 24 ~ 30 DEG C, the temperature effect of high comfort, resulting in unnecessary waste; low temperature heating is not up to the requirements.
In recent years, the state of building energy efficiency requirements continue to improve, the degree of insulation of the envelope structure is getting better and better, which makes the actual use of water temperature continues to decline. In the commonly used pipe diameter, pipe spacing under the premise that required the actual water temperature is lower than 50 DEG C, the outdoor temperature is not too low, 30 to the water temperature of 40 DEG C can play a significant effect. Low temperature radiation heating and heating system commonly used temperature is usually 45/35 C.
