An autonomous heating system and hot water supply in a private house will not surprise anyone. Be it a gas boiler, or a boiler installation, home equipment solves the problem of heating water, regardless of the centralized system. The following is the responsible distribution function of the coolant at the points of consumption. This infrastructure uses a heating pump, the efforts of which ensure the circulation of hot water.
Equipment device
The design of circulation pumps for heating systems is designed to ensure the forced movement of a liquid coolant. To do this, the power base of most of these units is equipped with motors - in particular, an asynchronous single-phase drive, which activates the function of the impeller. In addition to the electric motor, the typical design of pumps for heating boilers contains the following components:
- Housing provided with fittings.
- Screws for fasteners.
- Branch pipes for condensate discharge.
- Regulatory devices.
- Terminal block for electrical connection.
- Indicators, control buttons and switches.
- Transitional union and other adapters.
Technical designs of pumps of this type may vary in a variety of ways. In particular, by the type of lubrication of the rotary engine block. There are “wet” and “dry” designs. In the first case, the lubrication of the mechanics is carried out due to the flowing coolant, and in the second - with special technical oil. The second option is less attractive for the reason that particles of machine lubricant may remain in the water, and this affects the ecological purity of the water. However, for heating systems this factor is insignificant.
Equipment performance
The selection of a suitable model should begin with its admissibility to work in certain temperature conditions. As a rule, the heating pump is designed to be operated in direct contact with liquids whose temperature is 90-110 ° C. Next, you can proceed to the performance of the unit, consisting of a whole range of parameters:
- The pressure. It determines the height of water rise - in domestic systems it is 4-6 m, which is enough for a two-story house.
- Power. It affects both the height of the coolant and the flow rate. Modern models represent a wide range of indicators of this parameter, but at home, on average, 20-60 kW units are used.
- The 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 fluid passing through such a pump will be approximately 20 liters.
- Consumption. This value determines the performance of the system as a whole. It will be affected 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 coolant at a speed of more than 150,170 l / min.
The operating pressure is calculated separately. There are different approaches to assessing the optimal load that a pump can withstand. Sometimes a rule is applied, according to which 1 m of water rise corresponds to 0.1 atm. However, experts argue that 6 bar is enough in a domestic heating infrastructure - the most common calculated pressure value that manufacturers themselves indicate. In an extreme case, when servicing multiple supply points in a large house, a 10 bar unit may be involved.
The principle of the pump
The impeller of the unit during rotation creates an effect on the fluid flow, as a result of which the circulation speed changes. Depending on the intensity of the impeller and the pressure level required to raise the coolant, 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 opportunities for changing the speed of the impeller. This function is implemented differently in manual mechanical and electronic models. In the first case, the user can control the power through several stages of regulation. At peak rates of reduction in the frequency of rotation of the impeller, energy savings of up to 20% can be achieved. Electronic pumps, however, perform automatic selection of the optimal water speed, taking into account several indicators. Thus, the most rational circulation is provided with minimization of heat loss and without compromising comfort in microclimate indicators.
Assembly Installation Rules
The pump is installed on the coolant circuit in a pipe of a suitable size. Fastening is carried out with the help of complete fittings with additions in the form of measuring instruments - manometers, thermometers and flow sensors. When installing the heating pump , the following rules must be observed:
- Before working, a comprehensive flushing of the pipeline should be carried out.
- The mounting point should be in an accessible place for possible inspections and maintenance.
- Shutoff valves are mounted on both sides relative to the pump installation point - at the inlet and outlet.
- During installation, it is important to observe the correct position of the rotor. According to the instructions, it should occupy a horizontal position, protected from possible deviation. Offsets will result in loss of performance.
- 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, having previously unscrewed the fixing screws.
- Installation on long pipelines 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 joints and the correct flow direction are checked. The actual circulation vector must correspond to the arrow of the movement of the working medium indicated on the unit body.
Heating pump connection
Electrical activities are carried out 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, the power cable must not be allowed to come into contact with the pipes and the pump casing. 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. Next, an electrical wire connection is made through the terminal block . It is important to maintain the tightness of the box, protecting the contacts from moisture. If a special two-layer insulation is not provided in the pump design, then grounding should be provided separately.
Equipment manual
When the system is mounted and connected, you can prepare it for the first turn on. For this, air is vented. The pipeline is first filled and then completely emptied from the air. Modern pump models provide automatic air exhaust through a special ventilation function. To do this, there is a corresponding button, after which the pressure is increased and decreased in the system. The procedure lasts only a few seconds. Then you can proceed to adjust the pump for the heating system according to your current needs. In particular, the adjustment method, pressure and power are set. In the presence of a display with the operating parameters of the device, you can track the set indicators, as well as record critical values. Automation is configured for emergency operations - in cases of overheating, idling, severe voltage drops in the network, etc.
Pump Maintenance Instructions
Regularly clean the surfaces of the pump. This is done with a dry rag or rag. It is important not to damage the sensitive elements, eliminating contamination of components and small parts. Harsh cleaning products and abrasives should be discarded. If malfunctions are found, then you should use the universal repair manual for heating pumps with the effect of circulating motion:
- The unit does not work, although the power is working properly and is connected. This is often the result of an erroneous operation or breakdown of the fuse.
- Heating circuits do not heat up. The actual figures may not correspond to the established values. It is necessary to increase the heating temperature and the speed of the flow. If the situation does not change, the control unit is repaired.
- The pump vibrates excessively and makes noise. As a rule, this is 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.
Grundfos Pump
Under the Grundfos brand, some of the most reliable and technologically advanced pumps are produced. The assortment of the company provides a wide category of circulation models for heating systems - both regulated and unregulated. In particular, the initial level is a compact UPS pump, equipped with an asynchronous motor with a wet rotor. He has a manual gearshift in three modes. Also, mechanical correction of the rotor is done by hand without automation.
The current generation of adjustable circulation models is the extensive ALPHA family. The third generation of the Grundfos pump of this series combines elements of manual hydraulic balancing and electronic control. To constantly monitor operating parameters, the homeowner can use a smartphone or iPad - mobile devices are synchronized with the pump control unit, receiving the latest data remotely.
The design of ALPHA pumps is also evolving, gaining ever new qualities and capabilities. The engine, as one of the key components of the unit, is provided by high-strength ceramic bearings and a rotor shaft. These solutions increase equipment life and productivity. Grundfos specialists also work on the protective and insulating qualities of pumps, increasing their resistance to external influences.
Wilo Pumps
Also notorious company in the market of pumping equipment. In this case, you should pay attention to the Star-RS line, whose representatives are guided by the increase in heat transfer when servicing the heating system circuits. The manufacturer counts on the design of the equipment for continuous operation in harsh conditions. Moreover, even small-format models can be used not only in everyday life, but also on large highways of hot water supply. A working pressure of 16 bar allows this.
The average technical indicators of Wilo heating pumps cover a performance range that will be sufficient to service areas from 200 to 1000 sq. M. At the same time, both low-power and high-performance units are optimized as much as possible in the design, which simplifies maintenance and generally makes the infrastructure more reliable. If we talk about branded 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 graphite wear-resistant basis.
Features of heat pumps
Another category of pumping equipment that is used for the heating function. These are electromechanical units that provide air conditioning and hot water supply in conjunction with other heating devices, as well as in stand-alone mode. The target coolants of such equipment are hot air and water. Heat pumps for heating of this type have two functional parts in the design: a hydraulic module and a unit with an inverter. The first component is installed inside a boiler room or other room where the generation of warm streams is planned. The inverter is mounted outside on the street. It is fixed by means of special brackets to the wall or on the floor on a prepared foundation. Two blocks are connected through the route, including copper pipes and a four-wire electrical cable.
The principle of operation of a heat pump for heating a house is to take in the outside air and transfer it through the inverter unit to consumers. Temperature control is carried out by means of a coolant (freon), which is introduced into the circulating infrastructure and transferred to water. The action diagram resembles the operation of an air conditioner, as does the technical device. The difference lies in the fact that the heat pumps also function effectively in fan coil mode, that is, they support the regulation of both lowering and raising the temperature. As a rule, the equipment is automated using sensors that detect deviations from the optimal microclimate parameters.
Conclusion
Pumping 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 predetermined contours. This is how circulating water heating pumps work. The main characteristics of the system are set by the source of thermal energy. It can be both stand-alone equipment like a boiler or convector, and a heating main, in which there is a lack of pressure. As for air-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 trusted with circulation pumps.