Connecting a water flow sensor for the pump. Purpose of the flow switch. Design and principle of operation

Replacing power and return branches

Which installer can make mistakes and what are the consequences? In the area between the collector and the solar group Incorrect connection of the solar collectors inadvertently leads to the pump. This is due to the fact that the temperature sensor is located where the medium cooled in the heat exchanger returns to the collector. The temperature sensor heats up and gives a signal to start the pump, and then it is immediately cooled by the incoming medium. How to check the position of the sensor? Check the position of the sensor when the pump is running and in strong sunlight by touching the wires.

The sensor should be on the hot branch of the installation. If the collector temperature recorded by the regulator is lower than the temperature read by the thermometer in the solar group, this is evidence of the return of the power source. The liquid cooled in the heat exchanger and the pipes are pumped to the sensor. Cooled in the heat exchanger of the solar cylinder, the liquid should be pumped in the direction of return of the solar collectors. If we manually turn on the solar pump in the evening with a heated reservoir, the return must be warm.

Ways to protect pumps from running without water

If it turns out that the power is warm, this confirms the return of power. If, when filling the system on the reverse side, the temperature immediately drops, and not after a certain period of time, this is a sign that the sensor is in return. In the area between the solar panel and the storage tank. In this case, the hot medium from the bottom of the coil is fed into the solar heat exchanger. This leads to a violation of the temperature layers in the tank and too little cooling of the return branch and, as a result, a decrease in the efficiency of the installation.

Starting pipes in a vertical ventilation duct

Collectors are connected to the solar panel below. As a result, the solar group is connected to a power source and is exposed to high temperatures. This is due to the exhaustion of heat from the pan. Before choosing a tray, check how large the room in which it will be installed.

Typically, installers prefer to use piping for solar collectors located on the roof in a vertical vent or chimney. How does the chimney react when using an active chimney and what are the consequences? Assuming an inactive chimney is being used, the installer should use insulated pipes during the assembly phase. Installing insulation on previously laid pipes will never provide complete insulation. The installer collects the pipes all the time after the height, so they exit the chimney.

And at this moment a problem may arise if it turns out that the “birds get” in order to isolate the isolation. Firstly, the openings in the insulation are heat losses, and secondly, moisture can penetrate through such insulating openings, especially when the insulating openings are near the chimney and rain drops will drain under the pipes into the chimney. How does this insulation work? On the roof of a hot manifold, in a tank of cold water. It is resistant to a wide range of temperatures, atmospheric influences and ultraviolet radiation with the required thickness, no one should convince that the kit should be solar insulation.

Check where the solar collectors are located relative to the world. The cables of the solar system were directed to the roof, and there may be another problem if you find that you have purchased a kit with inadequate mount for solar collectors. Typically, the installer sees this before assembling the collectors and quickly replaces the correct one. Worse, if the installer saves on the purchase of a compass and informs the client that the roof on which the assemblers gather is to the south and actually will be eastern or western, not to mention the case when the assemblers are installed on the northern slope, because this road is visible from the road, and the owner depends only on prestige.

Correct installation filling

A solar installation may not achieve the desired performance at this time. When filling out the installation, there are three main methods. Through the ventilation and gas station, the station allows you to flush and fill the solar circuit. The filter used at the station allows you to separate any impurities remaining after welding the pipes, any residues inside the absorber and the coil of the solar cylinder. Rinse with water if there is no need to rinse at low temperatures, and there is a problem of freezing.

If a rotameter is used in the installation, it should be remembered that it allows only flow in one direction and at the same time is a valve blocking the unwanted flow direction. With a manual pump, the installation is flushed with tap water until the dirt leaves the installation. The solar fluid in the container is pumped through the hand pump, the shut-off valves under the ventilation holes must be open. The pump must be connected to the filling nozzle at the lowest point and fluid will be pumped into the unit so that air can escape through the ventilation holes.

At that moment, when the liquid begins to flow out, the liquid must be closed. Continue to press until the desired pressure is reached. Before filling the system, it is necessary to check the refueling pressure in the expansion tank, which is 1.5 bar. The pre-pressure should be such that in all operating conditions at the highest point there is an excess pressure that can displace the air bubbles that accumulate there. If you decide to independently prepare your own solar fluid, it is important to remember that in order to provide the necessary protection against freezing, it is important to ensure the correct proportion between the solar fluid concentrate and water.

Figure 2 Location of the expansion vessel. Solar system ventilation is the most common cause of systemic interference. Most of the air appears in the solar circuit due to improper filling and ventilation. Therefore, special attention must be paid to this problem. If there is a relatively high flow rate in the solar system, for example, if a “too strong” pump is used, it is often difficult to eliminate air problems in the installation. The reasons for the accumulation of air in the installation.

Defective horizontal pipes, improperly installed ventilation openings, improper filling of the system, improper pre-pressure in the expansion vessel, small pipe diameters, which lead to high flow rates, air bubbles remaining after filling, air suction under vacuum at the pump connections, installation and pressure drop. - The lower the pressure, the less air gets water. - The higher the temperature, the less air can remain in the water. When the liquid cools, the air will again be absorbed by water.

Air bubbles accumulated in the unit cause a number of problems. Insufficient fluid flow in the hydraulic circuit, noise coming out of the system, lack or insufficiency of “heat transfer”, low efficiency of solar collectors, the possibility of corrosion and accelerated aging due to air, the possibility of precipitation in pipelines, overheating Mounting elements, such as a circulation pump , which can be accelerated, cause erosion of the installation components that are in contact with moving air. The cost of fixing a problem can be substantial and difficult to calculate.

To prevent the appearance of unwanted air bubbles in the solar system, you must carefully install and fill it. The installer should read the following notes. A solar installation usually needs to be filled slowly, so that a moving heating fluid pushes air through the ventilation openings of the system. To ensure proper filling, it is recommended to use gas stations for simultaneous ventilation. Solar collectors should be mounted lightly to the air vent, so that air that tends to move upward from the installation through the air vent at the highest point when using manual air vents should be vented several times during the first filling of the system when air bubbles recur. for ventilation during operation of the system, the emission of air particles depends on the flow rate of the fluid and the diameter of the pipe, air bubbles thus becoming involved in the system down, the position and shape of the holes should allow rapid air leakage, any leakage in the system leads to a pressure drop, which can cause the absorption of atmospheric air. In the coil of a solar cylinder, air can last quite a while.

If the check valve in the power circuit can be opened with the solar pump turned off, some of the air may move up to the collector. A rotary screw is installed on the axis of the solar pump, and air exits the pump. However, it should be expected that some fluid will come out of the pump. Ventilation holes must be located at the highest points so that air space accumulates underneath. The holes can be manual or automatic air vents, using automatic ventilation holes should be aware of the location of the shut-off valve.

Components of the solar system - possible errors in assembly and use

Too risky when steam leaves the system, when the system stagnates through the vent. The controller is installed in a place where it can be sprayed with a liquid or a heat source, possibly next to other power lines. Operational interaction or short circuit Incorrect controller settings are usually caused by installers reluctance to read the operating instructions. Typical errors are: too low minimum collector temperature - installation too late to get started; too low minimum temperature - cooling capacity; maximum storage temperature - a low value leads to unnecessary shutdown of the solar pump; Too high, in turn, the risk of overheating of the cartridge; Incorrect operation - error messages, uncontrolled operation, etc. The plate must be connected so that the quick coupler is directly on the ship. This happens for a simple reason: with this connection, the diaphragm of the vessel always comes in contact with the liquid, and there is no danger of it “drying out”, since the airbag on the diaphragm will go out of the way, avoiding the accelerated aging of the diaphragm and leakage. The hose of the vessel should be led from the solar group to the descending vessel so that air can leave it. Due to this arrangement of hoses, heat from the solar circuit bypasses the membrane of the vessel. The quick release valve is closed. This causes the vessel to cut itself off from the solar circuit and, consequently, a pressure surge until the safety valve can work. The flowmeter regulator valve is in a position that causes the flow to cut or flow too restrictively. You should strive to work with a fully open valve and automatic flow control regulator. Inadequate pump stroke. The effect is too high or too low. Too high a flow rate leads to low collector temperatures, and a too low flow rate in summer can lead to difficulties in leakage of heat into the tank. Install the stream in accordance with the manufacturer's instructions. The absence of a protective anode leads to a lack of protection of the enamel of the cartridge and, as a result, to accelerated wear. Corrosion occurs between the container and the material of the connecting material, or if the container enamel is too tight, use surface seals. Follow the installation instructions and set the correct temperature to prevent burns or obstruct the user at low temperatures. Check valves cannot cause heat circulation and cooling of the storage tank, and hot water can occur in undesirable places. Circulation connection, improper connection of the circulation circuit can lead to damage to the circulation pump. It is advisable to use the option of the controller, which allows you to temporarily turn on the circulation pump. It is best to use a circulation regulator that minimizes energy loss. Leakage of connections. Pay attention to the tightness of the immersion sleeve, the control flange and the plug that covers the coupling to the heater. When placing the sensor in the sleeve, care must be taken to prevent it from slipping, providing at least linear contact between the sensor and the sleeve and placing it on the power source, as well as a seal that prevents penetration into the water sleeve and contamination. The temperature sensor cable should be routed into the housing and protected from possible damage, for example by bending it in the wind. Under no circumstances should plastic pipes be used in the immediate vicinity of collectors. Use only solar insulation, heat resistance, ultraviolet and atmospheric. Incorrect installation of pipe "humps" in the installation leads to the inevitable accumulation of air. If you cannot avoid them, use a local air vent. In the case of flexible pipes with a certain structure that allows the accumulation of air in the pipes of the pipes, it is necessary to ensure their laying to a height.

• Temperature sensors are installed on the wrong seats.
• The result is a driver error signaling.
• The pump is attached to improper connections.
• The result is a lack of pump operation or uncontrolled operation.
• Incorrect installation of the expansion tank.
• The hose of the vessel must be connected to the quick connector from the top of the vessel.
• The combination of cold and warm water with sealed packages.
• No mixing valve or incorrect connection.
• Incorrect location and installation of the temperature sensor.
• Pipes must be resistant to high temperatures and solar fluids.
• Lack of air ducts may allow heat to circulate.