风冷热泵的除霜控制方法
(1)
较早采用的是定时除霜控制,这种控制往往按照最恶劣的环境条件来设定时间,因此在不同的环境条件下必然产生不必要的能源浪费。(2)
时间温度控制方法,这是目前普遍采用的方法,通过在时间量的基础上考虑了温度量,比单纯的时间法有进步,同时部分地考虑了机组工作环境的影响,但是仍不能很好地反映热泵机组在各种工况下公道除霜的题目。(3)
通过吸气管上的吸气压力可以得到饱和蒸发温度,当在蒸发器表面结霜严重时,蒸发温度与大气温度的差会加大,以饱和蒸发温度与环境温度的差值能较好的反映结霜情况,但是对于环境温度变化剧烈的场合仍会有误动作产生
聚氨酯软管 PVC软管 隔离墩模具 u型槽模具 护坡模具 pvc输送带 尼龙输送带 天津除甲醛 北京除甲醛 。(4)
由于蒸发器表面结霜,会增大蒸发器两侧的空气压差,通过检测蒸发器两侧的空气压差来确定是否需要除霜,这种方法可以实现根据需要除霜,但在蒸发器表面有异物或严重积灰时会误动作,而且微压差传感器的价格较高。(5)
以上的方法由于参变量较少,只能适用于某些工况,而在另一些工况时会产生误操纵。可以通过引进参数如环境温度、环境湿度、翅片盘管表面温度(
或通过压力传感器得到盘管蒸发温度) 、制热运行时间、翅片盘管表面温度与环境温度的差值( 或盘管蒸发温度与环境温度的差值)
及翅片盘管温度的变化率( 或盘管蒸发温度的变化率) 等来综合考虑以达到降低不必要除霜的误动作。
(1) the timing defrosting control was adopted earlier. This control
often set time according to the worst environmental conditions.
Therefore, under different environmental conditions, unnecessary energy
waste is inevitable. (2) the time temperature control method, this
method is widely used, based on the amount of time is taken into account
in the amount of temperature, there is progress than the time only, at
the same time some influence of the working environment of the unit, but
still can not reflect the heat pump under different conditions of
reasonable defrosting topic. (3) through the suction pipe of the suction
pressure can be saturated when evaporating temperature in the
evaporator frosting is serious, evaporation temperature and atmospheric
temperature difference will increase, the difference of saturated
evaporation temperature and the ambient temperature can reflect the
frost condition better, but for the dramatic changes in the ambient
temperature occasions there will be false action. (4) because of
evaporator surface frost, will increase the air pressure difference on
both sides of the evaporator, through the detection of the evaporator on
both sides of the air pressure difference to determine whether there is
a need to defrost, this method can be realized according to the need to
defrost, but on the evaporator surface a foreign body or serious dust
will malfunction, and the price of micro differential pressure sensor
high. (5) the above method can only be applied to some working
conditions because of less parameter, and misoperation will be produced
in some other working conditions. Through the introduction of parameters
such as temperature, humidity, surface temperature of fin coil (or by
pressure sensor coil evaporation temperature, heating time difference),
fin coil surface temperature and the ambient temperature (difference or
coil evaporation temperature and ambient temperature) and the change
rate of the temperature changes (fin coil or coil evaporation
temperature the rate to consider) in order to reduce unnecessary
misoperation except fros