Water tank for air source heat pump
As a part of the air source heat pump heating safety system, the buffer
water tank has the function of decompression and protection for the running
host. When an enterprise provides an air source heat pump heating system, if
the buffer tank is not added, it is likely to cause the unit to start
frequently. When the control flow is low, the unit is also prone to alarm, and
insufficient water flow will cause many problems. Therefore, during the
operation of the air source heat pump heating system, the matching of the
buffer water tank is very important.
Under standard operating conditions, the number of start and stop times
of the host (that is, the number of compressor starts) is an important
parameter to measure the service life of the host, similar to the service life
of a home lamp switch is related to the number of on and off. Adding a buffer
water tank is equivalent to increasing the energy storage of the system, the
system temperature changes smoothly, the number of start and stop of the host
is naturally reduced, and the service life is prolonged.
In some countries in Europe and America, the buffer tank is a standard
configuration. Some manufacturers even refused to debug at the construction
site of the machine room without a buffer water tank.
In the long-term use, it is found that the air source heat pump buffer
tank has some unique functions in addition to the above advantages:
1. The forced automatic exhaust function in the system
If only the function of reducing the number of start and stop times of
the main engine is required, the buffer water tank can be installed in the main
engine water outlet pipe or indoor return water pipe. When the water tank is in
the return pipe of the system, it will be found that the circulating water
enters from the upper part of the water tank and discharges from the lower
part. At this time, the gas in the water will accumulate in the upper space of
the water tank, and the pressure in the closed system will automatically force
the gas to be discharged from the upper exhaust valve. It will not happen that
when we install an exhaust valve on a small pipe diameter, we need to drain a
small section of water before discharging the gas, and the lower part will
block a section of water, and the exhaust effect is extremely poor.
2. Protection of water pumps for power components in the water system
The bottom outlet of the buffer water tank is connected to the suction
port of the water pump. The water entering the suction port is gas-free (the
gas cannot come down in the upper part of the water tank), and the cavitation
phenomenon of the pump impeller will be greatly reduced. The inhaled water is
pure water, and the water circulating out of the pump will naturally push the
gas in the system to the system water outlet, and then enter the upper water
inlet of the buffer water tank. The gas brought by the system water outlet will
be forced out by the exhaust valve on the top of the water tank, and then
Become a virtuous circle. In a non-buffered water tank system, the water pump
sucks in airy water, and the impeller breaks the gas into the system, causing
the gas in the system to exist everywhere, making it more difficult to exhaust.
As a result, the flow switch of the water pump often alarms and starts and stops
continuously, which greatly increases the difficulty of debugging.
3. Avoid host high voltage protection
The water that enters the motherboard for exchange is pure (no gas)
water, which can better exchange energy and increase heat exchange efficiency.
4. Debugging is easier, and the end effect is faster
When the system is half filled with water, debugging can begin. The
water flowing into the main engine and the water pump is pure and airless, and
the heat will be quickly transported to the end, greatly reducing the debugging
time. The author was engaged in air-conditioning construction in the early
days, debugging a villa, and it was not finished within three to four hours.
Because there was too much air in the water, the flow switch frequently
alarmed, and the main engine was not heat exchanged enough to protect it from
high pressure. The effect is not obvious after the air block is blocked. All
make the debugging time greatly extend. In a computer room system with a buffer
water tank, debugging can generally be completed in one to two hours.
5. The system drains more thoroughly to prevent system blockage
The impurities in the pipeline are constantly circulating, because after
a vertical large-capacity water tank, many impurities will accumulate at the
bottom of the buffer tank, and the water quality through the Y-type filter is
much better, thereby reducing the number of times to clean the filter. . The
drain outlet of the buffer water tank is set at the bottom of the water tank
and is equipped with a manual drain valve, which makes cleaning more
convenient.
6. Heating in winter makes the system run more stable
When small air-cooled heat pumps are used in severe winter, the effect
of defrosting time on indoor temperature is a headache. If the host is equipped
with auxiliary electric heating to assist defrosting, it will greatly reduce
the cop value of the host. After the buffer water tank is added, when the main
engine is defrosted, the water at a certain temperature in the water tank can satisfy
the end circulation, completely avoiding the fluctuation of the indoor
temperature when the main engine is defrosted.
7. After booting, the use effect will come faster
Because after the first startup, the last cold or heat will be stored in
the buffer water tank. The insulation standard of the buffer water tank is the
same as that of the hot water tank (24 hours ± 3°C), so the next time it is
used , The effect will naturally come faster.
The air source heat pump buffer water tank plays a role in protecting the host. It can effectively solve the problem of load fluctuations and frequent start of the host caused by the system being too small. It mainly extends the start-up time of the host, reduces the number of starts and stops, and protects the life of the host. Energy-saving goals (pollution, exhaust).
