Air-water heat pump system with a rotary compressor

Abstract

The invention relates to an air-to-water heat pump series comprising several product classes classified according to their energy efficiency, each containing air-to-water heat pumps of a graded housing size and a graded nominal heating output, wherein the heat pumps comprise, in addition to a heat exchanger, a compressor, a condenser, an inverter, fans, a 4 / 2-way switching valve, a collector, an expansion valve, connecting pipes and a check valve and hydraulic components, wherein the finned tube heat exchangers in the housings of the same heat pump housing size from product classes of lower energy efficiency to product classes of higher energy efficiency have lower refrigerant-side pressure losses of the finned tube capillaries than in the housings of the same heat pump housing size from product classes of higher energy efficiency,and wherein in each product class, starting from the heat pump in the position of the stage with the highest rated heating output to the heat pump in the position of the stage with the lowest rated heating output, the same stage position is occupied by the same rotary piston compressor, whereby the compressor for the same stage position fully utilizes its speed range in the product class with the lowest energy efficiency and to a limited extent in the product classes with the higher energy efficiency.

Description

[0001] The invention relates to an air-water heat pump series comprising several product classes classified according to their energy efficiency, each containing air-water heat pumps of a graded housing size and a graded nominal heating output, wherein the heat pumps comprise, in addition to a heat exchanger, a compressor, a condenser, an inverter, fans, a 4 / 2-way switching valve, a collector, an expansion valve, connecting pipes and a check valve and hydraulic components.

[0002] An air-to-water heat pump is an environmentally friendly and efficient solution for extracting heat from the outside air. It absorbs heat from the ambient air and raises it to a higher temperature using a refrigerant circuit. The heat extracted from the ambient air is then used for both heating and hot water production. An air-to-water heat pump operates efficiently even at low outside temperatures and reduces energy consumption and CO2 emissions compared to conventional heating systems. It is capable, for example, of sustainably extracting heat from the ambient air, which can easily meet the heating and hot water needs of a single-family home.

[0003] The air-to-water heat pump draws in outside air via an integrated fan. The heat from the air is transferred to a refrigerant via an evaporator. A compressor compresses the refrigerant, thereby raising it to a higher temperature. This refrigerant, now at a higher temperature, releases heat energy to the condenser, which can then be fed into the heating water in a home's heating circuit, heating it. Air-to-water heat pumps use refrigerants that are highly efficient for their application, even at low outside temperatures. R290 (propane), for example, has proven to be a suitable refrigerant.

[0004] The primary function of an air-to-water heat pump is to provide heating or hot water. However, they can be equipped with a circuit reversal and thus used for space cooling. This applies the principle of active cooling, where the heat energy is absorbed from the building's interior and released into the environment via the refrigerant circuit.

[0005] There is a growing desire to replace less environmentally friendly heating systems, such as those based on oil and gas, with more environmentally friendly heating systems. Since conventional heating systems are in widespread use, the relevant industry is required to produce a correspondingly large number of environmentally friendly air-to-water heat pumps at a purchase price that does not overburden household budgets, taking into account government subsidies.

[0006] The industry is therefore required to provide high-quality air-to-water heat pumps with the aforementioned required components at affordable costs for customers. The design of the air-to-water heat pump series plays a crucial role in this. To date, smaller series have been implemented and no distinction has been made in the class classification. This is associated with high development costs, which increases the costs of air-to-water heat pumps. This leads to the use of air-to-water heat pumps with a low specific nominal heating output, since only a small number of different nominal heating outputs are available. This, in turn, results in oversized heat pumps being used in cases of doubt, since the required heating output is significantly below the provided nominal heating output if no "more suitable" heat pump with a nominal heating output matching the heat demand is available.This increases the costs for the users of the heat pump.

[0007] Until now, performance variation was limited to narrow ranges. Accordingly, a multitude of different heat pumps, each with individual development effort, were necessary for different performance and efficiency requirements.

[0008] A disadvantage of the current state of the art is that the cost-saving potential of standardized series of air-water heat pumps has not been fully exploited.

[0009] During the development of a new air-to-water heat pump series using R290 as the refrigerant, it was recognized that as unit volumes increase, price pressure on the devices will continue to increase. To counteract this, there is a need to standardize the devices across the entire performance, energy efficiency, sound, and cost spectrum.

[0010] One object of the invention is therefore to create a production-optimized, simple, cost-effective and very broadly positioned heat pump series.

[0011] This object is achieved by the subject matter of claim 1. The dependent claims relate to expedient and inventive developments of this invention.

[0012] The invention accordingly provides an air-water heat pump series comprising several product classes classified according to their energy efficiency and / or noise emission, each containing air-water heat pumps of a graded housing size and a graded nominal heating output, wherein the heat pumps comprise, in addition to a heat exchanger, in particular an air-refrigerant heat exchanger, a compressor, a condenser, an inverter, fans, an optional 4 / 2-way switching valve, an optional collector, an expansion valve, connecting pipes and an optional check valve and optional hydraulic components.

[0013] A first air-water heat pump with a first of the graded housing sizes in a first of the product classes provides a first nominal heating output and the first heat pump with the first housing size provides a second nominal heating output different from the first nominal heating output in a second of the product classes, wherein the first heat pump in the first and second product classes each has a heat exchanger with the same dimensions, wherein the first heat pump in the first and second product classes differs in at least one of the following features: a compressor displacement, a design temperature and / or number of plates of the condenser, a fan size, and / or the expansion valve.

[0014] In versions of the series, in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position can be occupied with the same heat pump housing size and the same size heat exchanger, which provides a different nominal heating output of the heat pump in relation to the energy efficiency of the respective product class.

[0015] Furthermore, the housing of the same heat pump housing size can have a finned tube heat exchanger with identical height dimensions, with identical number of tube rows, with identical distributions, with identical entanglement and with identical diameter of the collecting tube.

[0016] Furthermore, the heat exchanger, in particular the finned tube heat exchanger, in product classes of greater energy efficiency relative to their respective stage position can have a larger number of tube rows, more complex distributions and a larger diameter of the header tube than the heat exchangers in product classes of lower energy efficiency relative to their respective stage position.

[0017] In addition, the finned tube heat exchangers in the housings of the same heat pump housing size from product classes of lower energy efficiency to product classes of higher energy efficiency can have lower refrigerant-side pressure losses of the finned tube capillaries than in the housings of the same heat pump housing size from product classes of higher energy efficiency.

[0018] Finally, in each product class, starting from the heat pump in the position of the stage with the highest rated heating output to the heat pump in the position of the stage with the lowest rated heating output, the same stage position can be occupied by the same rotary piston compressor, whereby the compressor for the same stage position fully utilizes its speed range in the product class with the lowest energy efficiency and to a limited extent in the product classes with the higher energy efficiency.

[0019] Advantageous developments of the invention provide: The same condenser type is used for all heat pumps, whereby in each product class, starting with the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the condenser in the same stage position has the same number of compressor plates in relation to the nominal output, whereby the condenser for the same stage position has a larger number of compressor plates in product classes with higher energy efficiency than in product classes with lower energy efficiency; for at least one of the air-to-water heat pumps of one of the housing sizes, a 1-phase inverter and a 3-phase inverter are used alternatively. Each of the air-to-water heat pumps of different housing sizes has one or more similar fans,The series is implemented with only two different fan sizes. - the heat pumps have a 4 / 2-way reversing valve, and in each product class, from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the heat pump in the same stage position has a 4 / 2-way reversing valve of the same size, whereby the 4 / 2-way reversing valves, starting from the heat pump in the position of the stage with the highest nominal heating output to a heat pump with a certain lower heating output in the position of the stage for the same stage position, have a larger or alternatively the same size in product classes with higher energy efficiency than in product classes with lower energy efficiency,and wherein below the specified lower heating output, all heat pumps in all product classes have 4 / 2-way reversing valves of the same size. The heat pumps have a collector for collecting refrigerant, and wherein in each product class, starting with the heat pump in the position of the stage with the highest rated heating output and ending with the heat pump in the position of the stage with the lowest rated heating output, the same stage position is occupied by a collector of essentially the same capacity.and wherein the volumes of the collectors within a product class are such that collectors with a larger capacity are used for larger heat pumps and collectors with a smaller capacity are used for smaller heat pumps; in each product class, from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position is essentially occupied by an expansion valve of the same size, and wherein, within a product class, larger expansion valves are used for larger heat pumps and smaller expansion valves are used for smaller heat pumps. In each product class, from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position within the refrigeration circuit is essentially occupied by connecting pipes of the same diameter,and wherein, within a product class, connecting pipes with a larger diameter are used for larger heat pumps and connecting pipes with a smaller diameter are used for smaller heat pumps; in each product class, from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position within the refrigeration circuit is essentially occupied by check valves of the same size, and wherein, within a product class, larger check valves are used for larger heat pumps and smaller check valves are used for smaller heat pumps; in each product class, from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position is essentially occupied by hydraulic components with the same flow capacity,and whereby, within a product class, hydraulic components with a larger flow capacity are used for larger heat pumps and hydraulic components with a smaller flow capacity are used for smaller heat pumps, and the same type of filter dryer is used for the heat pumps of all product classes.

[0020] Using the inventive series approach, a production-optimized, simple, cost-effective, and very broadly based heat pump production can be implemented with many common parts. The relatively low design effort required to implement the series allows for a broader product portfolio than with the state of the art. Furthermore, the application area of air-to-water heat pumps can be optimally adapted to specific requirements by specifically selecting the heating output spectrum and sound insulation of the air-to-water heat pumps. The same heat pumps are used in housings of the same size in the different product classes, but the air-to-water heat pumps operate with different energy efficiencies.

[0021] The invention is explained in further detail with reference to the exemplary embodiment shown in the drawing figures. They show: Fig. 1 in diagram form an air-water heat pump series designed according to the invention, comprising several product classes classified according to their energy efficiency, each containing air-water heat pumps of a graded housing size and a graded nominal heating output, Fig. 2 in diagram form the air-water heat pump series of Fig. 1 , in which the technical parameters of the heat pumps are entered into the representations that characterise them, Fig. 3 in diagram form the air-water heat pump series from Fig. 1 , comprising the indication of displacement volumes of rotary piston compressors of heat pumps, Fig. 4 in diagram form the air-water heat pump series of Fig. 1 specifying parameters of the condensers of the heat pumps, Fig. 5, 6in diagram form the air-water heat pump series of Fig. 1specifying the parameters of 1-phase and 3-phase inverters of the respective heat pump, Fig. 7 in diagram form the air-water heat pump series of Fig. 1 specifying the parameters of heat pump fans, Fig. 8in diagram form the air-water heat pump series of Fig. 1 specifying the parameters of 4 / 2-way switching valves of heat pumps, Fig. 9in diagram form the air-water heat pump series of Fig. 1 specifying the parameters of collectors of heat pumps, Fig. 10in diagram form the air-water heat pump series of Fig. 1 specifying the parameters of expansion valves of heat pumps, Fig. 11in diagram form the air-water heat pump series of Fig. 1 specifying the parameters of connecting pipes and check valves of the heat pumps, and Fig. 12 in diagram form the air-water heat pump series of Fig. 1 specifying the parameters of hydraulic components of the heat pumps.

[0022] Identical and structurally identical parts are provided with identical reference numbers. The figures may contain simplified or schematic representations. Different views of identical parts may be scaled differently.

[0023] The Figure 1 This diagram shows, by way of example, a schematic representation of an air-to-water heat pump series designed according to the invention. The diagram shows the heat pump's heating output on the x-axis, and three product classes classified according to the heat pump's energy efficiency are plotted on the y-axis.

[0024] The air-to-water heat pump series shown in the figure comprises three product classes: "Trend," "Plus," and "Premium," classified according to the heat pumps' energy efficiency and / or noise emissions. The "Trend" product class is characterized by the fact that it includes the air-to-water heat pumps in the series with the lowest energy efficiency and, simultaneously or alternatively, the highest noise emissions. The "Premium" product class is characterized by the fact that it includes the air-to-water heat pumps in the series with the highest energy efficiency and, alternatively or simultaneously, the lowest noise emissions. The "Plus" product class is characterized by the fact that it includes the air-to-water heat pumps in the series with energy efficiency that lies between the energy efficiency and / or noise emissions of the "Trend" and "Premium" product classes.Of course, the names of the three product classes are only examples and in other cases more than three product classes are conceivable.

[0025] Each product class contains a number of air-water heat pumps with a graduated heating output spectrum and graduated casing sizes 1 to 7, where 1 denotes the largest and 7 the smallest casing.

[0026] The "Trend" product class includes all housing sizes 1 to 7. The "Plus" product class includes housing sizes 1 to 6, and the "Premium" product class includes housing sizes 1 to 5. Therefore, the "Trend" product class includes a larger number of different heat pumps than the other product classes. In other versions, however, the number of heat pumps in each product class of the series may be the same.

[0027] Not every housing size is necessarily included in all product classes. However, if a heat pump of a certain housing size is included in multiple product classes, the nominal heating output of that heat pump of a certain housing size will vary between the multiple product classes. The principle is always consistent: the nominal heating output decreases from Trend to Plus to Premium, regardless of the housing size.

[0028] This allows multiple heat pumps with different nominal heating outputs to be implemented using a single housing size. The different nominal heating outputs enable product diversification while simultaneously allowing the reuse of many components, especially the housings. In particular, a relative reduction in the nominal heating output can be accompanied by an increase in the efficiency (COP) of the heat pump and a reduction in noise emissions. Thus, heat pumps in the exemplary Premium product class exhibit a higher efficiency (COP) and a lower noise emission value than heat pumps of the same housing size in the Plus and Trend product classes.

[0029] Each heat exchanger in the same stage position, i.e. with the same housing size, of the respective product class provides a different nominal heating output of the heat pump in relation to the energy efficiency of this product class.

[0030] The noise emissions of the three product classes are staggered so that the noise emissions are highest in the "Trend" product class and lowest in the "Premium" product class.

[0031] The heat pumps in the "Trend" product class manage to generate more heating output relative to the other two product classes. However, due to their slightly lower efficiency, more electrical energy is required to achieve the achievable heating output compared to the other two product classes, "Plus" and "Premium." In addition, the heat pumps in the "Trend" product class have comparatively high noise emissions. In other words, the heat pumps in the "Trend" product class are characterized by comparatively high power consumption at a lower purchase price, higher heating costs, and higher noise emissions.

[0032] The heat exchangers in this case are finned tube heat exchangers. The finned tube heat exchanger meets the requirements of the series for an outdoor air-to-water heat pump using R290 refrigerant. With its respective design, the product classes classified according to energy efficiency with their air-to-water heat pumps with graded nominal heating output can be implemented as described below. The same fin type (corrugated and hydrophilic coated) can be used for all finned tube heat exchangers.

[0033] In Fig. 2 The parameters that determine energy efficiency and heating output are entered into the respective heat pumps. In particular, the dimensions of the heat exchanger, the tube rows, the distributions, the capillary pressure drops, and the collecting pipe diameters are specified as examples for each heat pump. Size of the heat exchanger

[0034] The size of the heat exchanger is essentially decisive for the efficiency of the heat pump, whereby the efficiency of the heat pump also increases with the size of the heat exchanger.

[0035] The aim here is to provide as few different heat exchangers as possible in order to increase the number of components that can be reused between multiple heat pumps. For this reason, the width of the heat exchangers is preferably kept as uniform as possible. In this example, the heat exchangers of heat pump sizes 1, 2, 3, 4 and 5 all have a width of, for example, 800 mm. Preferably, heat pump sizes 1, 2, 3, 4 and 5 all have the same footprint and differ from each other only in height. The heat exchangers of heat pump sizes 6 and 7 have a smaller width of, for example, 550 mm, primarily due to unit size and cost requirements. The width is reduced because the heat exchanger operated as an evaporator should remain as square as possible to provide sufficient space for the fan.The height of the heat exchangers, however, varies depending on the heating output, with higher heating output being associated with a greater height of the heat exchangers: The heights of the heat exchangers become smaller according to the housing sizes from 1 to 7.

[0036] The series is divided into 3 classes (Premium, Plus, Trend).

[0037] In this example, the entire series consists of seven different evaporators, which are used in the respective device classes. Each evaporator is assigned to a corresponding housing size.

[0038] The evaporator size increases with increasing requirements. This means that a Trend device utilizes a high level of heating power with the available evaporator size. This ratio is already smaller for Plus devices, and it decreases even further for Premium devices, meaning that Premium devices have a relatively large evaporator for the heating power.

[0039] Since the size of the evaporator is essentially decisive for the efficiency of the heat pump, the efficiency of the heat pump also increases with the increasing evaporator size and thus the first step in differentiating the classes (the efficiency) is implemented.

[0040] An additional point for efficiency is the reduction of the refrigerant side pressure loss with increasing evaporator size at the same size, which also improves the evaporation temperature.

[0041] In addition to the pressure loss on the refrigerant side, the larger evaporator (in this case, a larger frontal area) also reduces the pressure loss on the air side at the same flow rate. This reduces the fan power at the same flow rate.

[0042] Or a larger volume flow can be achieved with the same fan power, which leads to improved efficiency.

[0043] Alternatively, the air volume flow can be reduced at the same evaporation temperature, so that the noise level of the heat pump is reduced.

[0044] Another factor is the larger aluminum fin surface area of the heat exchanger resulting from the larger evaporator, which extends the time until defrosting is necessary during evaporator operation. This also increases the efficiency of the heat pump.

[0045] Due to these effects, the different requirements of the three device classes in terms of sound, efficiency, heating capacity and costs can be met by using different evaporator sizes with the same performance. Tube rows of the heat exchangers

[0046] The number of tube rows of the heat exchanger, both in depth and width, is also crucial for the efficiency of the heat pump, with the efficiency of the heat pump increasing with the number of tube rows.

[0047] The heat exchangers of heat pump sizes 1, 2, 3, 4, and 5 have four rows of tubes in depth. The heat exchanger of heat pump size 6 has three rows of tubes in depth. Heat exchanger distributor

[0048] All heat exchangers use the same type of distributor, but differ in the following aspects, which are also crucial for the efficiency of the heat pump: the number of distributors, the diameter of the injection line, and the cross-sectional area of the distributor nozzle (the sum of the internal cross-sections of the capillaries). The diameter of the capillaries is the same for all variants; they differ only in their length. Entanglement of the heat exchangers

[0049] The heat exchangers of heat pump sizes 1, 2, 3, 4, and 5 feature the same mesh pattern, which increases in complexity with increasing height. Optionally, a different mesh pattern or the same mesh pattern can be used in the other heat exchangers of heat pump sizes 6 and 7. Reduction of the refrigerant-side pressure loss of the heat exchangers

[0050] An additional way to increase energy efficiency is to reduce the refrigerant side pressure drop with increasing heat exchanger size, which also improves the evaporation temperature (optimized).

[0051] In addition to the pressure loss on the refrigerant side, the larger heat exchanger also reduces the pressure loss on the air supply side at the same flow rate due to its larger frontal area. This reduces the fan power of the heat exchanger at the same flow rate. Alternatively, a higher flow rate can be achieved with the same fan power, which leads to improved energy efficiency. Alternatively, the air flow rate can be reduced at the same evaporation temperature, thus reducing the noise emissions of the heat pump.

[0052] The refrigerant-side pressure losses are shown as an example in Fig. 2shown. The heat exchanger in the size 1 housing has a refrigerant-side pressure drop of 2.19 bar in the "Premium" product class, a refrigerant-side pressure drop of 2.76 bar in the "Plus" product class, and a refrigerant-side pressure drop of 3.90 bar in the "Trend" product class.

[0053] The heat exchanger in the size 2 housing has a refrigerant-side pressure loss of, for example, 1.75 bar in the "Premium" product class, a refrigerant-side pressure loss of, for example, 2.95 bar in the "Plus" product class, and a refrigerant-side pressure loss of, for example, 3.170 bar in the "Trend" product class.

[0054] The heat exchanger in the size 3 housing has a refrigerant-side pressure loss of, for example, 1.33 bar in the "Premium" product class, a refrigerant-side pressure loss of, for example, 2.016 bar in the "Plus" product class, and a refrigerant-side pressure loss of, for example, 3.01 bar in the "Trend" product class, and so on.

[0055] Fig. 3 shows in diagram form the air-water heat pump series from Fig. 1 whose heat pumps, operated with the refrigerant R290, are equipped with compressors of different displacement volumes.

[0056] Depending on the size of the heat pump and the rated heating output, compressors with different displacements are used. For example, rotary piston compressors are used for compressors with smaller displacements up to approximately 80 cc. For larger displacements, scroll compressors or other compressors can be used.

[0057] It is intended that heat pumps of the same casing size in different product classes will be equipped with the same compressor. Furthermore, it is intended that heat pumps of the same casing size in different product classes will be equipped with different compressors. For example, the same compressor will be used in the Trend and Plus product classes, while a larger compressor will be used in the Premium product class with the highest efficiency or lowest noise emissions. This will reduce noise emissions in the higher-end product class.

[0058] The design of the displacement volumes, which varies from refrigerant to refrigerant, refers in this case to the refrigerant R290 and a compressor speed range of 15-120 Hz. The actual displacement volumes used may vary slightly depending on the available displacement volumes of the manufacturers.

[0059] The concept is designed so that compressors in the "Trend" product class utilize their speed range almost completely, which means that the compressors in question are noisier in the upper speed range and have lower efficiencies at higher speeds due to internal pressure losses.

[0060] In the "Plus" product class, the upper speed range is limited to approximately 90 to 105 Hz, and in the "Premium" product class to approximately 65-95 Hz. This results in a different relationship between displacement and nominal heating output depending on the product class.

[0061] By reducing the utilization of the operating range, the noise emissions of the compressors are reduced and efficiency is increased.

[0062] Fig. 4 shows in diagram form the air-water heat pump series from Fig. 1Specifying the types of condensers used in the heat pumps. Preferably, the same condenser type is selected for all heat pumps, although the dimensions may vary depending on the heat pump. For example, in the case of plate heat exchangers as condensers, the number of condenser plates varies between the different heat pumps.

[0063] In the example of Fig. 4 7 condenser types A, B, C, D, E, F, G are illustrated, which, for example, decrease in the number of plates from A to G.

[0064] In more detail, in each product class, from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the condenser in the same stage position has the same number of compressor plates, whereby the condenser for the same stage position has a larger number of compressor plates in product classes with higher energy efficiency than in product classes with lower energy efficiency. However, it is entirely possible that, for example, in the Premium product class, condensers are used for a certain casing size, which are used differently for a larger casing size in the other product classes. This is due to the fact that the nominal heating output for heat pumps in the Premium product class is lower than the nominal heating output of the other product classes for the same casing size.

[0065] The basis for the design of the condensers is that the heat pumps of the "Trend" product class are designed for a nominal heating output (according to the heating curve) of A2 (outside temperature +2°C). For the "Premium" product class, the heat exchangers are designed for a nominal heating output of A-7 (outside temperature -7°C). The heat exchangers of the "Plus" product class are designed for a nominal heating output between the nominal heating outputs of the "Trend" and "Premium" product classes. For example, the same condensation temperature is selected as the design temperature in each case.

[0066] Fig. 5 and Fig. 6 show the air-water heat pump series from Fig. 1 specifying the parameters of 1-phase inverters ( Fig. 5 ) and 3-phase inverters ( Fig. 6 ) of the respective heat pumps.

[0067] The power range of the single-phase inverters is limited to approximately 6-7 kW of electrical power. For the three-phase inverters, the power range is limited (the nominal power of the heat pump with 5 kW is in the Fig. 5 unspecified).

[0068] The inverter design is selected so that the inverter output of the "Trend" product class heat pumps is just sufficient for A-7 / W55 (outside temperature -7°C and hot water temperature 55°C). The inverter design of the "Premium" product class heat pumps is selected so that the full performance range can be achieved even at high flow temperatures. The inverter output of the "Plus" product class heat pumps is between the outputs of the "Trend" and "Premium" product classes.

[0069] In addition, a distinction is made between the associated fan modules in the inverters, with one or two fan modules being used depending on the size and type of the inverter.

[0070] The information on connected loads is only exemplary and not exhaustive, which is also indicated by the question marks in some cases. A key insight of the inventors of this series is that heat pumps of the same housing size in different product classes can be connected with a different number of phases, for example, housing size 4.

[0071] Fig. 7 shows in diagram form the air-water heat pump series from Fig. 1 specifying the parameters of the heat pump fans.

[0072] The heat pumps of the entire series, with their three product classes, are designed to be equipped with just two different fans (diameters are given as examples: 450 mm and 630 mm). If one fan cannot provide the required airflow, or if poor air distribution is expected due to the size differences between the fan and heat exchanger, two fans of the same diameter can be used.

[0073] The combination of the air flow rate of the fan(s), the pressure drop of the heat exchanger and the fan diameter ensures the desired balance between noise emissions and energy efficiency, with a larger air flow rate resulting in higher noise emissions and a larger heat exchanger and a larger fan resulting in lower noise emissions.

[0074] Fig. 8 shows in diagram form the air-water heat pump series from Fig. 1specifying parameters of the 4 / 2-way switching valves of the heat pumps.

[0075] The switching valve located in the refrigerant circuit is designed to ensure that pressure losses are just acceptable for heat pumps in the "Trend" product class and that excessive noise is avoided. For heat pumps in the "Plus" and "Premium" product classes, the switching valve is oversized to ensure lower pressure losses.

[0076] It has therefore proven advantageous that the switching valves in different product classes for heat pumps of the same casing size can be quite different.

[0077] Since the size of the switching valves in the lower range is limited to a technically feasible maximum, there is no longer any differentiation between the valves below 10 kW rated power. Accordingly, the number of different switching valves is small, just three in the example shown, keeping the complexity of the series low.

[0078] Instead of the changeover valve A shown for the most powerful heat pumps, a design with several, for example two or three, changeover valves is also possible.

[0079] Fig. 9 shows in diagram form the air-water heat pump series from Fig. 1 specifying parameters of the heat pump collectors, namely a volume of the refrigerant collectors.

[0080] A similar approach is used for the collector as for the other components.

[0081] The volume of the collector depends essentially on the internal volume of the evaporator and the condenser of the heat pump, therefore the collector is adapted to the heat pumps according to the component sizes.

[0082] The series is implemented with three or four different collector sizes, depending on the design of the heat pumps in casing size 1. In any case, it is sufficient to provide three different collector sizes, thus covering a performance range that spans approximately a factor of 10, namely from just under 3 kW to approximately 25 kW of nominal heating output.

[0083] Furthermore, the connection points (position and connection diameter) are kept the same for the various collectors, wherever possible. This allows the same pipes to be used as often as possible.

[0084] Fig. 10 shows in diagram form the air-water heat pump series from Fig. 1specifying parameters of the heat pump expansion valves.

[0085] The expansion valves are adapted to the specific heat pump type. The valves are used in multiple heat pumps. Furthermore, the heat pumps in this series are equipped with expansion valves in such a way that the valve connections are identical over large areas, allowing the same connecting pipes to be used.

[0086] Fig. 11 shows in diagram form the air-water heat pump series from Fig. 1 specifying groups of connecting pipes and check valves of the heat pumps.

[0087] The different heat pumps in the series are surrounded by lines of different structures, i.e. bold solid line, solid line, thin solid line and three forms of different dashed lines.

[0088] The pipe dimensions were designed to ensure that pressure losses are just acceptable for heat pumps in the "Trend" product class and do not cause excessive noise. For the "Plus" and "Premium" product classes, the diverter valve is oversized to ensure lower pressure losses in these heat pumps.

[0089] In addition, the pipe diameters are selected so that as many pipes as possible can be used as identical parts.

[0090] The check valves are designed to ensure acceptable pressure losses for heat pumps in the "Trend" product class without excessive noise. For the "Plus" and "Premium" product classes, the check valves are oversized to ensure lower pressure losses.

[0091] With this in mind, the same pipe diameter and check valve configuration is available across all product classes for housing sizes 1 and 2. For housing sizes 3, 4, 5, and 6, the configuration is the same for both the Trend and Plus product classes, while housing sizes 3, 4, and 5 have a custom configuration of pipes and valves for the Premium product class.

[0092] Fig. 12 shows in diagram form the air-water heat pump series from Fig. 1 specifying classes of hydraulic components of the heat pumps. As in Fig. 11 The different heat pumps of the series are surrounded by lines of different structures, i.e. bold solid line, dashed line and solid line.

[0093] Due to the different housing sizes and product classes, there are only three different designs of hydraulic components.

[0094] The diameters of the hydraulic hoses, the connectors in the hydraulic system, the size of the refrigerant (KM) separator, and the external connection of the heating hydraulics are selected so that the series can be implemented with two different sizes: Hydraulic hoses: NW 26 and NW 32; connectors: NW 20 and NW 26; KM separators: small and large; external hydraulic connection: 1 1 / 4" and 1 1 / 2",

[0095] The volume flow sensor is divided into three sizes for the series so that the volume flow for the devices can be measured down to the minimum volume flow and the pressure loss remains acceptable.

[0096] All hydraulic components are designed in such a way that the pressure losses for heat pumps in the "Trend" product class are just acceptable. For heat pumps in the "Plus" and "Premium" product classes, the selected series approach automatically reduces pressure losses to reduce the required pump power.

[0097] Not shown in the figures is the filter dryer included in each heat pump. The same adequately dimensioned type of filter dryer is used for each heat pump. Using the same type of filter dryer for all heat pumps ensures a significant reduction in the variance of connection and connecting pipes, as well as a significant reduction in the number of spare parts.

Claims

1. Air-water heat pump series, comprising several product classes classified according to their energy efficiency and / or noise emission, each containing air-water heat pumps of a graded casing size and a graded nominal heating output, wherein the heat pumps comprise, in addition to a heat exchanger, in particular an air-refrigerant heat exchanger, a compressor, a condenser, an inverter, a fan, an expansion valve and connecting pipes, characterized in thata first air-water heat pump with a first of the graded housing sizes in a first of the product classes provides a first nominal heating output and the first heat pump with the first housing size in a second of the product classes provides a second nominal heating output different from the first nominal heating output, wherein the first heat pump in the first and second product classes each has a heat exchanger with the same dimensions, wherein the first heat pump in the first and second product classes differs in at least one of the following features: - a displacement volume of the compressor, - a design temperature and / or number of plates of the condenser, - a size of the fan, and / or - the expansion valve.

2. Series according to claim 1, wherein the same condenser type is used for all heat pumps, wherein in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the condenser in the same stage position has the same number of compressor plates in relation to the nominal output, wherein the condenser for the same stage position has a greater number of compressor plates in product classes of higher energy efficiency than in product classes of lower energy efficiency.

3. Series according to claim 1 or 2, wherein for at least one of the air-water heat pumps of one of the housing sizes, a 1-phase inverter and a 3-phase inverter are used alternatively.

4. Series according to claim 1, 2 or 3, wherein each of the air-water heat pumps of different housing size has one or more similar fans, wherein the series is implemented with only two different fan sizes.

5. Series according to one of claims 1 to 4, wherein the heat pumps have a 4 / 2-way switching valve and wherein in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the heat pump in the same stage position has a 4 / 2-way switching valve of the same size, wherein the 4 / 2-way switching valves, starting from the heat pump in the position of the stage with the highest nominal heating output to a heat pump of a certain lower heating output in the position of the stage for the same stage position in product classes of higher energy efficiency, have a larger or alternatively the same size than in product classes of lower energy efficiency, and wherein below the certain lower heating output, all heat pumps in all product classes have 4 / 2-way switching valves of the same size.

6. A series according to any one of claims 1 to 5, wherein the heat pumps have a collector for collecting refrigerant, and wherein in each product class, starting from the heat pump in the position of the stage with the highest rated heating output to the heat pump in the position of the stage with the lowest rated heating output, the same stage position is occupied by substantially a collector of the same capacity, and wherein the volumes of the collectors within a product class are used for larger heat pumps, collectors with a larger capacity, and for smaller heat pumps, collectors with a smaller capacity.

7. Series according to one of claims 1 to 6, wherein in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position is occupied by an expansion valve of substantially the same size, and wherein within a product class, larger expansion valves are used for larger heat pumps and smaller expansion valves are used for smaller heat pumps.

8. Series according to one of claims 1 to 7, wherein in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position within the refrigeration circuit is occupied essentially with connecting pipes of the same diameter, and wherein, within a product class, connecting pipes with a larger diameter are used for larger heat pumps and connecting pipes with a smaller diameter are used for smaller heat pumps.

9. Series according to one of claims 1 to 8, wherein in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position within the refrigeration circuit is occupied with check valves of substantially the same size, and wherein within a product class, larger check valves are used for larger heat pumps and smaller check valves are used for smaller heat pumps.

10. Series according to one of claims 1 to 9, wherein in each product class, starting from the heat pump in the position of the stage with the highest nominal heating output to the heat pump in the position of the stage with the lowest nominal heating output, the same stage position is occupied essentially with hydraulic components with the same flow capacity, and wherein, within a product class, hydraulic components with a larger flow capacity are used for larger heat pumps and hydraulic components with a smaller flow capacity are used for smaller heat pumps.

11. Series according to one of claims 1 to 10, wherein the same type of filter dryer is used for the heat pumps of all product classes.

Images