You will not surprise anyone with an autonomous heating and hot water supply system in a private house. Whether it is a gas boiler or a boiler plant, domestic equipment solves the problem of heating water independently of a centralized system. This is followed by a responsible function of the distribution of the coolant at the points of consumption. This infrastructure uses a heating pump that circulates hot water.
Equipment Arrangement
The design of circulation pumps for heating systems is designed to provide forced movement of the heat transfer fluid. To do this, the power base of most of these units is supplied with motors - in particular, an asynchronous single-phase drive that activates the function of the impeller. In addition to the electric motor, a typical design of pumps for heating boilers contains the following components:
- Casing provided with fittings.
- Mount screws.
- Condensate drain pipes.
- Adjusters.
- Terminal block for electrical connection.
- Indicators, control buttons and switches.
- Reducing fitting and other adapters.
Technical designs of pumps of this type may differ in a variety of ways. In particular, by the type of lubrication of the rotor block of the engine. There are "wet" and "dry" designs. In the first case, the mechanics are lubricated due to the flowing coolant, and in the second case, with special technical oil. The second option is less attractive due to the fact that particles of machine lubricant can remain in the water, and this affects the ecological purity of water. However, this factor is insignificant for heating systems.
Equipment performance
The selection of a suitable model should begin with its suitability for operation in certain temperature conditions. As a rule, the heating pump is designed to be able to operate in direct contact with liquids whose temperature is 90-110 °C. Then you can move on to the performance of the unit, which is made up of a whole range of parameters:
- Head. Determines the height of the water rise - in household systems it is 4-6 m, which is enough for a two-story house.
- Power. It affects both the height of the coolant rise and the speed of its supply. Modern models area wide range of indicators of this parameter, but at home, units of 20-60 kW are used on average.
- Volume of fluid passage in 1 minute. If the power of the equipment in the circuit is the same 20 kW, then the average volume of the passing fluid for such a pump will be approximately 20 liters.
- Expense. This value determines the performance of the system as a whole. It will be influenced not only by the characteristics of the pumping unit, but also by the diameter of the connected nozzles. For example, with the same heating pump power of 20 kW, a circuit with a thickness of about 25 mm, on average, provides a flow rate of 30 l / min. A pipe with a diameter of 50 mm can supply heat transfer fluid at a rate of over 150-170 l/min.
In a separate order, the working pressure is calculated. There are different approaches to estimating the optimal load that a pump can withstand. Sometimes the rule is applied, according to which 1 m of water rise corresponds to 0.1 atm. However, experts say that 6 bar is quite enough in domestic heating infrastructure - the most common calculated pressure value, which is indicated by the manufacturers themselves. As a last resort, when serving multiple supply points in a large house, a 10 bar unit may be used.
Pump principle
The impeller of the unit during rotation creates an effect on the fluid flow, resulting in a change in the circulation rate. Depending on the intensity of the impeller and the level of pressure required for liftingcoolant, the difference between the rates of movement of water at the inlet and outlet changes. During the operation of water equipment, regulatory functions are especially important. The principle of operation of a heat pump for heating a house provides for the possibility of changing the speed of the impeller. This function is implemented differently for manual mechanical and electronic models. In the first case, the user can control the power through several stages of regulation. At peak rates of impeller speed reduction, energy savings of up to 20% can be achieved. Electronic pumps perform automatic selection of the optimal speed of water movement, taking into account several indicators. Thus, the most rational circulation is ensured with minimization of heat losses and without compromising comfort in terms of microclimate.
Unit installation rules
The pump is installed on the coolant circulation circuit in a pipe of a suitable size. Fastening is carried out using complete fittings with additions in the form of measuring instruments - a pressure gauge, a thermometer and a flow sensor. When installing a heating pump, the following rules must be observed:
- Complete flushing of the pipeline must be performed before working steps.
- The mounting point must be in an accessible location for possible inspections and maintenance.
- Isolation valves are mounted on both sides of the pump installation point - at the inlet and outlet.
- When installing, it is important to observethe correct position of the rotor. According to the instructions, it must take a horizontal position, protected from possible deviation. Offsets will result in performance loss.
- The terminal block must also be open for direct access. In some models of the heating pump, its position can be changed together with the motor housing by first unscrewing the fixing screws.
- Installation on long piping lines may involve risks of increased vibration. In this case, poorly fixed pipe ends are additionally fixed to the supporting structures.
After installation, the quality of the mechanical connections and the correct flow direction are checked. The actual circulation vector must correspond to the flow arrow of the working medium indicated on the unit body.
Heating pump connection
Electrical measures are performed only with the appropriate skills. For work on circuits with a water temperature of more than 90 ° C, a special heat-resistant cable is used. During the connection process, the power wire must not be allowed to come into contact with the pipes and the pump housing. Before connecting directly with a multimeter, the characteristics of the mains are checked. They must match the parameters of the heating pump according to the recommended performance indicators. Further, the electrical connection of the wire is made through the terminal block. It is important to maintain the tightness of the box, protecting the contacts from moisture. If the pump design does not provide for special two-layer insulation, then separatelygrounding should also be provided.
Equipment instruction manual
When the system is mounted and connected, you can prepare it for the first start. For this, air is removed. The pipeline is first filled and then completely emptied of air. Modern models of pumps provide for automatic air venting through a special ventilation function. To do this, there is a corresponding button, after pressing which the pressure in the system is increased and decreased. The procedure takes only a few seconds. Then you can proceed to adjust the pump for the heating system, taking into account current needs. In particular, the method of adjustment, pressure and power are set. If there is a display with the operating parameters of the device, you can monitor the set indicators, as well as fix critical values. Automation is configured for emergency operation - in cases of overheating, idling, strong voltage drops in the network, etc.
Pump Maintenance Instructions
Pump surfaces should be cleaned regularly. This is done with a dry cloth or rag. It is important not to damage the sensitive elements, relieving knots and small parts from contamination. Avoid aggressive cleaners and abrasives. If problems are found, then you should use the universal repair instructions for heating pumps with the effect of circulating movement:
- The unit does not work, although the power is good and connected. This is often the result of a faulty fuse or blown fuse.
- Heating circuits are not warming up. It is possible that the actual values do not correspond to the set values. It is necessary to increase the heating temperature and the flow rate. If the situation does not change, the control unit is being repaired.
- The pump vibrates excessively and is noisy. This is usually the result of too low pressure on the water. The problem is solved either by increasing the pressure in order to eliminate the effect of cavitation, or by reducing the pressure.
Pump "Grundfos"
Under the Grundfos brand, some of the most reliable and technologically advanced pumps are produced. The company's product range includes a wide category of circulation models for heating systems - both adjustable and unregulated. In particular, the entry level is a compact UPS pump, provided with a wet rotor asynchronous motor. He has manual gear shifting in three modes. Also, the mechanical correction of the rotor is done by hand without automation.
The modern generation of adjustable circulation models represents the extensive ALPHA family. The third generation of the Grundfos pump of this series combines elements of manual hydraulic balancing and electronic control. The homeowner can use a smartphone or iPad to constantly keep track of operating parameters - mobile devices are synchronized with the pump control unit, receiving fresh data remotely.
The design of ALPHA pumps is also developing, acquiring new qualities and capabilities. The engine, as one of the key components of the unit, is provided with high-strength ceramic bearings and a rotor shaft. These solutions increase equipment life and productivity. Grundfos specialists are also working on the protective and insulating qualities of pumps, increasing their resistance to external influences.
Wilo pumps
Also a well-known company in the market of pumping equipment. In this case, you should pay attention to the Star-RS line, whose representatives are guided by an increase in heat transfer when servicing the heating system circuits. The manufacturer expects equipment designs for continuous operation in harsh conditions. Moreover, even small-format models can be used not only in everyday life, but also on large hot water mains. An operating pressure of 16 bar allows this.
The average technical performance of Wilo heating pumps covers a performance range that will be sufficient to serve areas from 200 to 1000 square meters. At the same time, both low-power and high-performance units are maximally optimized in design, which simplifies maintenance and, in general, makes the infrastructure more reliable. If we talk about proprietary developments, then the company relies on the use of gray cast iron in the design. The shaft, in turn, is made of stainless steel, and the bearings are made on a wear-resistant graphite base.
Heat pump features
Another category of pumping equipment that is used for the heating function. These are electromechanical units that provide air conditioning and hot water supply both in conjunction with other heating devices, and in standalone mode. The target coolants of such equipment are hot media of air and water. Heat pumps for heating of this type have two functional parts in their design: a hydraulic module and a unit with an inverter. The first component is installed inside the boiler room or other room where the generation of warm flows is planned. The inverter is mounted outside on the street. It is fixed by means of special brackets to the wall or floor to the prepared foundation. Two blocks are connected through a route that includes copper pipes and a four-wire electric cable.
The principle of operation of a heat pump for heating a house is to take in outside air and transfer it through an inverter unit to consumers. Temperature regulation is carried out by means of a coolant (freon), which is introduced into the circulating infrastructure and transferred to the water. The scheme of action resembles the operation of an air conditioner, as well as a technical device. The difference lies in the fact that heat pumps operate effectively in fan coil mode, that is, they support regulation both for lowering and increasing the temperature. As a rule, the operation of equipment is automated using sensors that record deviations from the optimal microclimate parameters.
Conclusion
Pump units in heating systems mainly perform an auxiliary function. As such, they do not generate heat, but only support the distribution of the coolant along the given contours. This is how water heating pumps of the circulation type work. The main characteristics of the system are set by the source of thermal energy. This can be autonomous equipment like a boiler or a convector, and a main heat supply network in which there is a lack of pressure. As for air-to-water pumps, they are effective in cases where fine-tuning of microclimatic parameters inside one or two rooms is required. But for a large private house, one such installation will not be enough. Comprehensive maintenance of several heating circuits is best left to circulation pumps.
