Air-water heat pump series with finned tube heat exchanger

Abstract

The invention relates to 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 graduated housing size and a graduated nominal heating output, wherein a first air-water heat pump with a first of the graduated housing sizes and a first heat exchanger of a first heat exchanger size in a first of the product classes provides a first nominal heating output and the first heat pump with the first housing size and the first heat exchanger 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.

Description

[0001] The invention relates to a series of air-water heat pumps, 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.

[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, transfers heat energy to the condenser and heats the water in a home's heating circuit. Air-to-water heat pumps use refrigerants that demonstrate high efficiency for their application, even at low outside temperatures. For example, R290 (propane) 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 reverse cycle and thus used for room cooling. This utilizes the principle of active cooling, where heat energy is absorbed from the 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 a plurality of product classes classified according to their energy efficiency and / or noise emission, each containing air-water heat pumps of a graduated housing size and a graduated nominal heating output, wherein a first air-water heat pump with a first of the graduated housing sizes and a first heat exchanger of a first heat exchanger size in a first of the product classes provides a first nominal heating output and the first heat pump with the first housing size and the first heat exchanger 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 an air-refrigerant heat exchanger with the same dimensions.

[0013] Advantageous developments of the invention according to the first aspect provide: The finned tube heat exchangers in the casings of the same heat pump casing size exhibit lower refrigerant-side pressure drops of the finned tube capillaries from product classes with lower energy efficiency to product classes with higher energy efficiency than in the casings of the same heat pump casing size from product classes with higher energy efficiency. The finned tube heat exchangers within a product class of the same energy efficiency in casings of smaller design exhibit lower refrigerant-side pressure drops of the finned tube capillaries than in casings of larger design, whereby the refrigerant-side pressure drop between two adjacent casing sizes can alternatively be the same. The height dimension of the respective heat exchanger within a product class increases with increasing heating output. The number of tube rows of the respective heat exchanger within a product class increases with increasing heating output.The complexity of the distributions of the respective heat exchanger within a product class increases with increasing heating output. The diameter of the header tube of the respective heat exchanger increases with increasing heating output within a product class. The same fin type, corrugated and hydrophilically coated, is used for all finned-tube heat exchangers. The same type of distributor is used for all finned-tube heat exchangers, which differs depending on the position of the stages in the heating output spectrum in the following respects: number of distributors, diameter of the injection line, cross-sectional area of the distributor nozzle (sum of the internal cross-sections of the capillaries). The diameter of the capillaries is the same for all variants, but the capillaries differ in their length.The product classes differ from one another in the noise emissions of the air-to-water heat pumps, with heat pumps in a higher-energy-efficient product class having lower noise emissions than those in a lower-energy-efficient product class. Each product class has the same number of heating output ranges and casing size levels. Alternatively, the product classes have different numbers of heating output ranges and casing size levels, with lower-energy-efficient product classes having more nominal heating output and casing size levels than the higher-energy-efficient product classes.

[0014] 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 characterize them, and Fig. 3 in diagram form the air-water heat pump series from Fig. 1 , in which further technical parameters of the heat pumps are entered in the representations that describe them.

[0015] 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.

[0016] The Figure 1shows, as an example, a schematic diagram of an air-to-water heat pump series designed according to the invention. The diagram shows the heating output of the heat pumps on the x-axis, and three product classes classified according to the heat pumps' energy efficiency are plotted on the y-axis.

[0017] 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.

[0018] Each product class contains a number of air-water heat pumps with a graduated heating output spectrum and graduated housing sizes 1 to 7, where 1 denotes the largest and 7 the smallest housing.

[0019] 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, there is a larger number of different heat pumps in the "Trend" product class than in the other product classes. In other versions, however, the number of heat pumps in each product class of the series may be the same.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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

[0027] 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.

[0028] 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.

[0029] The series is divided into 3 classes (Premium, Plus, Trend).

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] In addition to the pressure loss on the refrigerant side, the larger evaporator (here, 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.

[0035] Or a larger volume flow can be achieved with the same fan power, which leads to improved efficiency.

[0036] Alternatively, the air volume flow can be reduced at the same evaporation temperature, so that the noise level of the heat pump is reduced.

[0037] 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.

[0038] 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

[0039] 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.

[0040] 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

[0041] 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

[0042] 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

[0043] 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).

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] In Fig. 3 are different suction line diameters ND and different sizes of injection lines for the heat pump of Fig. 1 and Fig. 2 shown.

[0049] The heat exchanger in the size 1 housing in the "Premium", "Plus", and "Trend" product classes has the following distribution parameters: ND: 28 x 1, injection line size: 16 x 1. The heat exchanger in the size 2 housing in the "Premium", "Plus", and "Trend" product classes, as well as in the size 3 housings in the "Plus" and "Trend" product classes, has the following distribution parameters: ND: 22 x 1, injection line size: 16 x 1. The heat exchanger in the size 7 and 4 housings in the "Plus" and "Trend" product classes has the following distribution parameters: ND: 18 x 1, injection line size: 12 x 1. The heat exchanger in the size 3 and 7 housings in the "Premium" product class has the following distribution parameters: ND: 22 x 1, injection line size: 16 x 1. The Heat exchanger in size 5 housing has the following distribution parameters in the "Plus" and "Trend" product classes: ND: 16 x 1, injection line size: 12 x 1.The heat exchanger in the size 4 housing in the "Premium" product class has the following distribution parameters: ND: 12 x 1, injection line size: 18 x 1. The heat exchanger in the size 6 housing in the "Trend" product class has the following distribution parameters: ND: 12 x 0.5, injection line size: 12 x 1.

Claims

1. Air-to-water heat pump series, comprising several product classes classified according to their energy efficiency and / or sound emission, each containing air-to-water heat pumps of a graded casing size and a graded nominal heating output, characterized in that a first air-water heat pump with a first of the graded housing sizes and a first heat exchanger, in particular an air-refrigerant heat exchanger, a first heat exchanger size in a first of the product classes provides a first nominal heating output and the first heat pump with the first housing size and the first heat exchanger 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.

2. Series according to claim 1, wherein the air-refrigerant heat exchanger of the first heat pump in the first and second product classes is designed as a finned tube heat exchanger with identical height dimensions, with identical number of tube rows, with identical distributions, with identical entanglement and / or with identical diameter of the collecting tube.

3. Series according to one of the preceding claims, wherein the finned tube heat exchangers in the housings of the same heat pump housing size from product classes of lower energy efficiency and / or noise emission 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.

4. Series according to one of the preceding claims, wherein the finned tube heat exchangers within a product class of the same energy efficiency have lower and / or the same refrigerant-side pressure losses of the finned tube capillaries in housings of smaller design than in housings of larger design.

5. Series according to one of the preceding claims, wherein the height dimension and / or the number of tube rows and / or the complexity of the distributions and / or the diameter of the header tube of the respective heat exchanger within a product class is greater with increasing heating output.

6. A series according to any one of the preceding claims, wherein each of the air-to-water heat pumps comprises a finned tube heat exchanger as the air-to-refrigerant heat exchanger, wherein the same fin type, corrugated and hydrophilically coated, is used for all finned tube heat exchangers.

7. Series according to one of the preceding claims, wherein the same type of distributor is used for all air-refrigerant heat exchangers, which differs in particular depending on the housing size in the following points: number of distributors, diameter of the injection line, cross-sectional area of the distributor nozzle (sum of the internal cross sections of the capillaries), and / or wherein the diameter of the capillaries is the same for all variants, but the capillaries optionally differ in their length.

8. A series according to any one of the preceding claims, wherein the product classes differ from one another in the sound emission of the air-water heat pumps, wherein the heat pumps of a product class of higher energy efficiency have a lower sound emission than a product class of lower energy efficiency.

9. Series according to one of the preceding claims, wherein the series comprises three product classes of different energy efficiency and / or different sound emissions.

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