WO2024039275A1

WO2024039275A1 - A method for controlling an operation of a modular fluid-fluid heat transfer arrangement and a modular fluid-fluid heat transfer arrangement

Info

Publication number: WO2024039275A1
Application number: PCT/SE2023/050820
Authority: WO
Inventors: Fredrik ROSENQVIST; Bengt Lindoff
Original assignee: Qvantum Industries Ab
Priority date: 2022-08-16
Filing date: 2023-08-14
Publication date: 2024-02-22

Abstract

A method (200) for controlling an operation of a modular fluid-fluid heat transfer arrangement (100) comprising a plurality of heat pump modules (130a, 130b) comprising a control unit (133) being connected to each control unit (133) of the other heat pump modules (130a, 130b) over a communication channel (140), and a memory (139) in which heat pump module configuration information relating to the associated heat pump module (130a, 130b) is stored, the method (200) comprising: a) transmitting associated heat pump module configuration information on the communication channel (140); b) receiving the associated heat pump module configuration information; c) storing said received heat pump module configuration information so as to provide a heat transfer arrangement configuration information; d) determining, based on the heat transfer arrangement configuration information, a master control unit selected from the control units (133), the control units (133) that are different from the master control unit are defined as slave control units; and e) transmitting operation control information from the master control unit to the slave control units. The disclosure further relates to a modular fluid-fluid heat transfer arrangement (100).

Description

A METHOD FOR CONTROLLING AN OPERATION OF A MODULAR FLUIDFLUID HEAT TRANSFER ARRANGEMENT AND A MODULAR FLUIDFLUID HEAT TRANSFER ARRANGEMENT

Technical field

The present disclosure relates to a method for controlling an operation of a modular fluid-fluid heat transfer arrangement. The present disclosure further relates to a modular fluid-fluid heat transfer arrangement.

Background art

Nearly all large, developed cities in the world have at least two types of energy grids incorporated in their infrastructures; one grid for providing electrical energy and one grid for providing space heating and hot tap water preparation. Today a common grid used for providing space heating and hot tap water preparation is a gas grid providing a burnable gas, typically a fossil fuel gas. The gas provided by the gas grid is locally burned for providing space heating and hot tap water. In order to reduce the carbon dioxide emissions there are plans to replace such gas grid with more “green” energy efficient energy systems.

One such energy efficient energy system is cold thermal grids. Cold thermal grids are an evolution of district heating and district cooling systems, where combined district heating and district cooling system with aid of using heat pumps for heating and cooling can provide both cooling, heating and tap water preparation to buildings.

In order to succeed with the replacement of gas grids, where the respective gas burner is replaced by a heat pump, the heat pumps used need to be smaller, less costly, easier to control and with lower technical complexity, e.g., with fewer and/or less complex sensors for measuring the space heat and tap water energy consumption than presently used heat pumps. Thus, the conventional heating and/or cooling systems are associated with several drawbacks. There is thus a need in the art for an improvement in this area.

Summary

It is an object to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solve at least the above mentioned problem.

It is an object of the disclosure to provide an efficient control method for a heat transfer arrangement.

Another object of the disclosure is to provide a time-efficient control method for a heat transfer arrangement.

Another object of the disclosure is to provide an accurate control method for a heat transfer arrangement.

Another object of the disclosure is to provide a cost-efficient control method for a heat transfer arrangement.

It is also an object to provide a cost-efficient heat transfer arrangement.

According to a first aspect, there is provided a method for controlling an operation of a modular fluid-fluid heat transfer arrangement, wherein the fluid-fluid heat transfer arrangement comprises a plurality of heat pump modules, each heat pump module comprising a control unit and a memory, in which memory heat pump module configuration information relating to the associated heat pump module is stored, said heat pump module configuration information including at least identification data unique to said associated heat pump module, and wherein the control unit of each heat pump module is connected to each control unit of the other heat pump modules of the plurality of heat pump modules over a communication channel, the method comprising: a) transmitting, by the control unit of each heat pump module, associated heat pump module configuration information on the communication channel; b) receiving, by the control unit of each heat pump module, the associated heat pump module configuration information transmitted from each of the other heat pump modules of the plurality of heat pump modules; c) storing, on the memory of each heat pump module, said received heat pump module configuration information so as to provide in said memory a heat transfer arrangement configuration information which includes the heat pump module configuration information of each heat pump module of the plurality of heat pump modules; d) determining, based on the heat transfer arrangement configuration information, a master control unit selected from the control units of the plurality of heat pump modules, wherein the one or more control units that are different from the master control unit are defined as slave control units; and e) transmitting operation control information from the master control unit to the slave control units.

Through-out the application text, the term “modular fluid-fluid heat transfer arrangement” will also be referred to as “heat transfer arrangement” or “arrangement”.

By the term “modular fluid-fluid heat transfer arrangement” is here meant an arrangement which comprises a plurality of heat pump modules which are separate from and independently of each other. Thus, the plurality of heat pump modules may be introduced in a housing or a zone, e.g., in a controlled space in which the plurality of heat pump modules is arranged, without the need of being attached, e.g., fastened, or mounted, to each other. The arrangement may be configured to cover, i.e. , being able to heat and/or cool and/or provide tap water to, an area. The area may be the whole, or a part of, the building. Thus, the fluid-fluid heat transfer arrangement may be configured to provide cooling or heating to a building, or a part of a building. If the arrangement is configured to provide heat to the building, the purpose of the arrangement is to supply heat from the cold to the hot side. If the arrangement is configured to provide cooling to the building (i.e. to remove heat therefrom), the purpose of the arrangement is to remove heat from the cold side. The disclosed method helps to control the operation of the modular fluid-fluid heat transfer arrangement in an easy and efficient way such that a required outlet temperature is provided. The required outlet temperature may be the temperature needed to fulfil heating and/or cooling and/or tap water requirements.

The one or more control units which are defined as slave control units are different from the master control unit. This implies that the one or more control units which are defined as slave control units are the control units of the plurality of control units which remains “unselected” after the selection of the master control unit has been made. Thus, the one or more control units which are defined as slave control units are the control units which are not the master control unit.

The fluid-fluid heat transfer arrangement may be a fluid-fluid heat pump arrangement configured to provide heat to the hot side fluid for heating the same.

The fluid-fluid heat transfer arrangement may be a fluid-fluid cool pump arrangement configured to remove heat from the cold side fluid for cooling the same.

As readily appreciated by the person skilled in the art, the fluid-fluid heat pump arrangement and the fluid-fluid cool pump arrangement is in principle the same, the only difference being what the end user is interested in to achieve heating or cooling. However, there may be differences between the two implementations of the general concept with regards to features such as e.g. the temperature range used in the hot and cold side grids.

By the term “control unit” is here meant any device or unit configured to control an operation of the associated heat pump module. Each heat pump module has a respective control unit which is configured to control the operation of the associated heat pump module. The control unit may be e.g. a microprocessor or a central processing unit, CPU, which is capable of making its own individual assessment based on operation control information from the master control unit together with input data from e.g. sensors. The memory of each heat pump module may be provided within the control unit. The memory of each heat pump module may be provided outside the control unit but may be in communication with the control unit.

By the term “communication channel” is here meant a connection over which the control units are connected to each other. The communication channel may be wired or wireless. Put differently, the control units may be either wired or wireless connected. The control units may be wired connected over a data bus such as for instance RS-485. The control units may be wireless connected via Wi-Fi, Bluetooth and/or cellular communication among other things. It should be understood that any communication means and/or protocol which is capable of interconnecting the control units to allow sending and receiving information in between them is equally applicable for the task. Thus, the way the communication channel is embodied should not be construed as limiting in this context.

As readily appreciated by the person skilled in the art, each heat pump module is configured to transmit its heat pump module configuration information on the communication channel by its control unit. Moreover, each heat pump module is configured to receive and store all transmitted heat pump module configuration information by its control unit. Hence, each heat pump module is preferably configured to be storing the same number of heat pump module configuration information. Moreover, each heat pump module is configured to determine the master control unit.

By the term “master control unit” is here meant a control unit which is configured to transmit operation control information to the slave control units. This implies that the master control unit will have the authority to decide how the heat pump arrangement is to be operated. However, each heat pump module is individually controlled by its control unit following the orders received from the master control unit. Thus, the master control unit does not directly control each and every aspect of the individual heat pump modules. In other words, based on the operation control information, the slave control units have knowledge about how to control its associated heat pump module. The master control unit may be configured to obtain control laws or control rules and based on these, transmit operation control information to the respective slave control unit. Thereby, the master control unit is configured to instruct the slave control units such that the arrangement is controlled in a desired way. Control laws may be stored on the respective control unit or received from a remote server connected to the communication channel. Put differently, the master control unit is, as already said, configured to transmit operation control information to the respective slave control unit but it is the respective slave control unit which is configured to control the associated heat pump module. The master control unit is also configured to control its associated heat pump module based on the operation control information. Thus, for the purpose of controlling its own heat pump module, the master control unit does not have to receive any operation control information, since it already has access thereto.

The master control unit may be determined by using a pre-configured rule. The pre-configured rule may comprise information and/or rules determining how the heat transfer arrangement configuration information should be treated and how the master control unit should be determined based on the heat transfer arrangement configuration information.

This is advantageous as it allows for a simplified controlling of each of the heat pump modules of the plurality of heat pump modules. This is further advantageous as it allows for simplified controlling of the modular fluid-fluid heat transfer arrangement. By determining a master control unit, the master control unit is allowed to receive and/or determine the operation control information and transmit the operation control information to the slave control units such that the respective slave control unit may control its associated heat pump module based on the operation control information.

The operation control information may comprise control laws configured to be transmitted to the slave control unit such that the slave control unit may be configured to control the operation of the associated heat pump module to operate in an operational mode. The operation mode may be common for all heat pump modules of the plurality of heat pump modules.

The operational mode may be defined by an input power, i.e. , compressor capacity, being common for all heat pump modules of the plurality of heat pump modules. This implies that every heat pump module is always operating at the same input power.

The method may further comprise individually controlling the operation of each heat pump module of the plurality of heat pump modules to allow operating each heat pump module at a respective operational mode.

The respective operational mode of each heat pump module may be based on a predetermined fraction of a maximum input power of that heat pump module, wherein the predetermined fraction is common for all heat pump modules. When the respective operational mode is based on the predetermined fraction, the operation control information may be the fraction and each slave control unit have to control the associated heat pump module based on the fraction.

The predetermined fraction may be determined based on a required arrangement output power Pout for the arrangement and a total maximum input power of all heat pump modules in the heat transfer arrangement. If dividing the required arrangement output power evenly between the maximum input power of all heat pump modules, the predetermined fraction is achieved. As said above, for this example embodiment, the predetermined fraction is common for all heat pump modules. Thus, if the predetermined fraction is 50% of the maximum arrangement output power, each heat pump module should operate with 50% of the heat pump modules respective maximum input power. For example, if the maximum input power of one heat pump module is 3 kW and of another heat pump module is 6 kW, the one heat pump module should operate with 1.5 kW and the other one with 3 kW.

The respective predefined operational mode of each heat pump module may be based on a predetermined time sequence alternating between a first state, where the heat pump module is not in operation, and a second state, where the heat pump module is operated at a predetermined input power.

By the term “slave control unit” is here meant a control unit which is, as already mentioned, configured to control its associated heat pump module based on the received operation control information transmitted by the master control unit. The slave control units may be configured to monitor the communication channel for instructions from the master control unit. The method may further comprise receiving, by the slave control unit of each heat pump module, operation control information from the master control unit, and controlling the operation of said heat pump module based on the operation control information.

This is further advantageous as it allows for an efficient method for controlling the modular fluid-fluid heat transfer arrangement. This is yet further advantageous as it allows for controlling the modular fluid-fluid heat transfer arrangement in an easy and flexible way.

This is yet further advantageous as it allows for a so called “plug and play” configuration protocol to be provided. The term “plug and play” should be interpreted as a set of networking or communication protocols that permits networked or connected devices, such as the control units of the respective heat pump module, to seamlessly discover each other’s presence in the arrangement and establish functional network services e.g. determining the master control unit as discussed above. The term “communication protocol” is here meant a system of rules that allows the control units to transmit information over e.g. the communication channel. The protocol may define rules, syntax, semantics and synchronization of communication and possible error recovery methods.

The step a) of transmitting, by the control unit of each heat pump module, associated heat pump module configuration information on the communication channel may be performed based on a communication protocol.

The communication protocol is in line with the communication protocol as discussed above. The communication protocol may be Aloha or may be based on a listen before talk (LBT) protocol. If the communication protocol is Aloha, the method may comprise starting a first timer and when the first timer expires, transmit the heat pump module configuration information. Thus, the communication protocol may determine a time period in which the communication channel is “open” such that the heat pump configuration information may be transmitted. The time period typically has the length of 1 to 60 seconds. If the communication protocol is the LBT protocol, a listen before talk procedure may declare when the communication channel is free such that the heat pump module configuration information may be transmitted. It should however be noted that other random-access protocols may be used as well.

As previously mentioned, the so called “plug and play” configuration protocol may be provided. Such a “plug and play” protocol may be advantageous as it allows to control the arrangement in an easy, efficient and accurate way also when replacing, adding or removing modules therefrom. This is further advantageous as it allows to control the arrangement in a flexible way.

This is further advantageous as it allows a robust way of reducing interference on the communication channel.

The method may further comprise determining a number of heat pump modules connected over the communication channel, and wherein the operation control information may be based on the number of heat pump modules.

This is advantageous as it allows for accurate and efficient control laws in order to determine the operation control information to be transmitted to the slave control units. Once the control laws is accurate and efficient, the operation control information may also be accurate and efficient, hence, an accurate and efficient controlling of the arrangement is provided. This is especially advantageous when every heat pump module is controlled to be operating at the same input power. The operation control information for each heat pump module may be determined based on the number N of heat pump modules operating in the arrangement and a total input power P of all heat pump modules of the arrangement. Assume that the heat transfer arrangement comprises N heat pump modules. In order to achieve a required outlet temperature in the hot fluid side, a total input power P for the heat transfer arrangement is needed. The master control unit may be transmitting operation control information to the respective slave control unit to instruct the slave control units to control the operation of the associated heat pump module such that each heat pump module operates in an operational mode which is common for all heat pump modules. Preferably, each heat pump module is supplied with the same input power. Thus, if dividing the total input power P evenly between the number N of heat pump modules operating in the heat transfer arrangement, each heat pump module will operate in an operational mode such that each heat pump module uses a common input power equal to P/N.

It should be noted that the number of heat pump modules comprised in the arrangement is dynamic e.g. the number of heat pump modules may changes if one or more heat pump modules are added or removed to/from the arrangement. In addition, the heat pump module comprised in the arrangement may be replaced by another heat pump module so as the number of heat pump modules are the same, but the heat transfer arrangement configuration information may be different.

If a new heat pump module is added to the arrangement, the number of heat pump modules increases by one i.e. N = N+1 . The added heat pump module may have to perform the steps a) to c) as discussed above such that the added heat pump module may have the same heat transfer arrangement configuration information stored in its memory as the other heat pump modules previously comprised in the arrangement. In addition, the heat pump modules previously comprised in the arrangement may have to update their stored heat transfer arrangement configuration information to include the heat pump module configuration information relating to the added heat pump module. Hence, the previously presented heat pump modules may have to perform step a) to c). Thereafter, the arrangement may have to determine if a new master control should be appointed or not based on the updated heat transfer arrangement configuration information.

If a replacement of a heat pump module has occurred, the steps a) to c) may have to be provided by both the added heat pump module and the previously presented heat pump modules such that the heat transfer arrangement configuration information may be updated in line with the discussion above.

If a heat pump module has been removed from the arrangement, the number of heat pump modules may be decreased by one i.e. N=N-1 . In this case, the steps a) to c) may have to be provided by the previously presented heat pump modules which may still be comprised in the arrangement such that the heat transfer arrangement configuration information may be updated in line with the discussion above.

In all the above identified cases, a new master control unit may be determined based on the updated heat transfer arrangement configuration information.

Prior to the step d) of determining the master control unit, the method may further comprise repeating the steps a) to c).

This is advantageous as it allows to verify that the stored heat pump module configuration information has been stored in a correct way. This is further advantageous as it allows for an improved and accurate method to be provided. It should however be noted that if the steps a) to c) are repeated, the arrangement and the control units may have knowledge about the repetition. Each control unit may have knowledge about a number of times the heat pump module configuration information has been received from the other control units of the plurality of control units. By way of example, if the repeating of the steps a) to c) has been performed a predetermined number of times, e.g. 3, 4 or 5 times, each control unit has the knowledge about that the heat pump module configuration information has been received said predetermined number of times from each of the other control units of the plurality of control units. Based on the received heat pump module configuration information, a majority decision may be performed such that a heat pump module configuration information associated to each heat pump module may be determined. By way of example, if the repeating of the steps a) to c) has been performed five times, and the heat pump module configuration information differs in one of these, the decision may be taken to assign the heat pump module configuration information received the other 4 times as the “correct” heat pump module configuration information on which to base decision of which heat pump model should be the master control unit. Preferably, one heat pump module configuration information associated to each control unit is stored in the respective memory although the heat pump module configuration information has been received a plurality of times. The repeating of the steps a) to c) may be performed a random number of times, preferably equal number of times for each heat pump module.

The repeating of the steps a) to c) may be performed a predefined number of times or repeatedly during a predefined time period.

This is advantageous as it allows to control the number of times or the timer period the repeating should be performed. As an example, the repeating of the steps a) to c) may be performed 5 to 10 times. It should however be noted that the repeating of the steps a) to c) may be performed other number of times as well.

If the repeating of the steps a) to c) are performed during a predefined time period, the method may further comprise starting a second timer, preferably when performing the step a) for the first time, wherein the repeating of the steps a) to c) are performed until the second timer expires. Hence, the second timer may be set to expire after ten minutes or the like. The second timer may be set to expire after any predefined time period. Preferably, the second timer is set to expire after 1 to 60 minutes.

The repeating of the steps a) to c) may be performed in response to that heat transfer arrangement configuration information retrieved from at least two heat pump modules are verified to be different.

This is advantageous as it allows to detect if something is wrong, either with the arrangement or with one or more of the heat pump modules.

The repeating of the steps a) to c) may be performed in response to that two or more control units are determined to be the master control unit. This may be the case when the output in step d) is different between two or more control units. If such a situation arises, the method may therefore be adapted to resolve the situation by once again performing the steps a) to c). This may be performed until only one control unit has been determined to be the master control unit.

The verification may be performed by: f) transmitting, by the control unit of each heat pump module, the heat transfer arrangement configuration information stored on the respective memory on the communication channel; g) receiving, by the control unit of each heat pump module, the heat transfer arrangement configuration information transmitted from each of the other heat pump modules; and h) comparing the received heat transfer arrangement configuration information so as to verify that the heat transfer arrangement configuration information of all heat pump modules is identical.

This may be referred to as a confirmation procedure configured to confirm that the heat transfer arrangement configuration information of all heat pump modules is identical. This is advantageous as it allows to verify if something is wrong, either with the arrangement or with one or more of the heat pump modules.

If heat transfer module configuration information between at least two heat pump modules is determined to be different, the verification may be performed by transmitting, by the control unit of the at least two heat pump modules, the heat transfer arrangement configuration information stored on the respective memory on the communication channel; receiving, by the control unit of the at least two heat pump modules, the heat transfer arrangement configuration information transmitted from each of the other heat pump modules; and comparing the received heat transfer arrangement configuration information so as to verify that the heat transfer arrangement configuration information of the at least two heat pump modules is identical.

Put differently, only the heat pump modules determined to have heat transfer arrangement configuration information being different participates in the confirmation procedure. This is advantageous as it allows for a simplified and efficient confirmation procedure.

The step f) of transmitting, by the control unit of each heat pump module, the heat transfer arrangement configuration information on the communication channel may be performed based on a further communication protocol. The further communication protocol may be the same as the communication protocol used for step a) but may alternatively be different. This is advantageous as it allows a robust way of reducing interference on the communication channel, and thereby also make the confirmation procedure fast.

The steps of f) to h) may be performed in response to the heat pump modules receiving a trigger signal.

The trigger signal may be output from, or at least initiated by, the master control unit. The trigger signal may be output in response to a third timer expiring. The third timer may be set to start after the step e) has been performed such that the time period the arrangement is running may be determined. Preferably, when the third timer expires, all heat pump modules may be configured to report their operation and their heat pump module configuration information and/or their heat transfer arrangement configuration information in order to verify that the arrangement is still running as desired. The third timer may be set to expire in the length of hours or days, such as 1 to 24 hours or 1 to 5 days. The trigger signal may be output in response to an error event being detected in one of the heat pump modules. The trigger signal may be output in response to a request from a remote server that in this way may trigger the confirmation procedure to be performed.

This is advantageous as it allows for detecting that the arrangement is running in a desired way at all times. This is further advantageous as it allows to detect if something is wrong with the arrangement or with one or more heat pump modules comprised in the arrangement.

This is further advantageous as it allows to simplify the addition or removement of heat pump modules to/from the arrangement as discussed above. This also simplifies maintenance and updates of the heat transfer arrangement.

The identification data may comprise an identity number, a serial number, a media access control, MAC, address and/or a Universal Unique Identifier, UUID. The identity number may be one or more numbers, one or more letters or a combination thereof. This is advantageous as it allows for each heat pump module to have unique identification data being associated to the specific heat pump module.

The step d) of determining the master control unit may be based on associated identification data of the plurality of heat pump modules. The master control unit may be determined by using a pre-determined rule. The pre-determined rule may receive the respective identification data of the plurality of heat pump modules as input data and based on the received identification data the pre-configured rule may output which of the control units should be the master control unit.

The method may further comprise heat pump module operational- specific data that may be relating to the associated heat pump module. The heat pump module operational-specific data may comprise maximum input power, minimum input power, cooling media required for the associated heat pump module, capacity, etc. relating to the associated heat pump module. As said above, the identification data is also specific for the respective heat pump module, but it is not operational specific. The maximum input power may, by way of example, be 3 to12 kW. However, other maximum input powers may be possible as well. The minimum input power may, by way of example, be 1 to 3 kW. However, other minimum input powers may be possible as well.

The step d) of determining the master control unit may be based on said heat pump operational-specific data.

By way of example, a pre-determined rule may receive the respective heat pump operation-specific data of the plurality of heat pump modules as input data and based on the received heat pump operation-specific data, the pre-configured rule may output which of the control units should be the master control unit. This is advantageous as it allows to determine the control unit associated to the heat pump module having e.g. the highest maximum input power. Hence, it is possible to control which control unit being the master control unit based on the operational-specific data.

By way of example, a pre-determined rule may receive the heat pump module configuration information of the respective heat pump module as input data and based on the received heat pump module configuration information, the pre-configured rule may output which of the control units should be the master control unit. Thus, the pre-determined rule may be formulated such that it combines the identification data and the heat pump operation-specific data in order to determine the control unit to be the master control unit. This may be advantageous if e.g. all heat pump modules have the same maximum input power and there is a need to distinguish the heat pump modules from each other such that one control unit is determined to be the master control unit.

According to a second aspect of the disclosure, these and other objects are also achieved in full or at least in part, by a modular fluid-fluid heat transfer arrangement comprising a plurality of heat pump modules, each heat pump module comprising a control unit and a memory, in which memory heat pump module configuration information relating to the associated heat pump module is stored, said heat pump module configuration information including at least identification data unique to said associated heat pump module, and wherein the control unit of each heat pump module is connected to each control unit of the other heat pump modules over a communication channel, the control unit of each heat pump module being configured to: transmit associated heat pump module configuration information on the communication channel; receive the associated heat pump module configuration information transmitted from each of the other heat pump modules; store, on the memory of the associated heat pump module, said received heat pump module configuration information so as to provide in said memory a heat transfer arrangement configuration information which includes the heat pump module configuration information of each heat pump module of the arrangement; and determine, based on the heat transfer arrangement configuration information, a master control unit selected from the control units of the plurality of heat pump modules, wherein the one or more control units that are different from the master control unit are defined as slave control units; wherein the determined master control unit is configured to transmit operation control information to the slave control units.

The slave control unit of each heat pump module may further be configured to control the operation of the associated heat pump module based on the operation control information received from the master control unit. The control unit of each heat pump module may be wired or wirelessly connected to the control unit of the other heat pump modules via the communication channel.

Effects and features of the second aspect are largely analogous to those described above in connection with the first aspect. Embodiments mentioned in relation to the first aspect are largely compatible with the second aspect. It is further noted that the inventive concepts relate to all possible combinations of features unless explicitly stated otherwise. A further scope of applicability of the present invention will become apparent from the detailed description given below. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from this detailed description.

Hence, it is to be understood that this invention is not limited to the particular component parts of the device described or steps of the methods described as such device and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only and is not intended to be limiting. It must be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context clearly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

The invention may also in short be said to relate to a method for controlling an operation of a modular fluid-fluid heat transfer arrangement comprising a plurality of heat pump modules comprising a control unit being connected to each control unit of the other heat pump modules over a communication channel, and a memory in which heat pump module configuration information relating to the associated heat pump module is stored, the method comprising: a) transmitting associated heat pump module configuration information on the communication channel; b) receiving the associated heat pump module configuration information; c) storing said received heat pump module configuration information so as to provide a heat transfer arrangement configuration information; d) determining, based on the heat transfer arrangement configuration information, a master control unit selected from the control units , the control units that are different from the master control unit are defined as slave control units; and e) transmitting operation control information from the master control unit to the slave control units.

Brief description of the drawings

The disclosure will by way of example be described in more detail with reference to the appended schematic drawings, which shows a presently preferred embodiment of the invention.

Figure 1 illustrates a modular fluid-fluid heat transfer arrangement.

Figure 2 is a flowchart illustrating a method for controlling an operation of a modular fluid-fluid heat transfer arrangement.

Detailed description

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and to fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout.

With reference to figure 1 , a modular fluid-fluid heat transfer arrangement 100 is illustrated by way of example. The modular fluid-fluid heat transfer arrangement 100 is preferably for heating and/or cooling and/or providing tap water to buildings or the like. Here after, the modular fluid-fluid heat transfer arrangement 100 is also be referred to as “heat transfer arrangement 100” or “arrangement 100”. The heat transfer arrangement 100 comprises a cold side and a hot side. The cold side comprises first inlet and outlet junction pipes 111 , 112. The cold side is connected to a cold fluid side 101 via the first inlet and outlet junction pipes 111 , 112 thereby forming a cold side fluid recirculation path 103. The hot side comprises second inlet and outlet junction pipes 122, 121. The hot side is connected to a hot fluid side 102 via the second inlet and outlet junction pipes 122, 121 thereby forming a hot side fluid recirculation path 104.

The first inlet junction pipe 111 is configured to supply a cold side first fluid from the cold fluid side 101 to the heat transfer arrangement 100. The first outlet junction pipe 112 is configured to supply a cold side second fluid from the heat transfer arrangement 100 to the cold fluid side 101 . Thereby the cold side fluid recirculation path 103 is formed. The cold side first fluid is preferably warmer than the cold side second fluid.

The second outlet junction pipe 121 is configured to supply a hot side first fluid from the heat transfer arrangement 100 to the hot fluid side 102. The second inlet junction pipe 122 is configured to supply a hot side second fluid from the hot fluid side 102 to the heat transfer arrangement 100. Thereby the hot side recirculation path 104 is formed. The hot side first fluid is preferably warmer than the hot side second fluid.

The fluid-fluid heat transfer arrangement 100 may be a fluid-fluid heat pump arrangement configured to provide heat to the hot side fluid for heating the same. The fluid-fluid heat transfer arrangement 100 may be a fluid-fluid cool pump arrangement configured to remove heat from the cold side fluid for cooling the same.

For typical heating applications of the arrangement 100, the cold fluid side 101 may be an evolution of district heating and district cooling systems, where combined district heating and district cooling system with aid of using heat pumps for heating and cooling can provide both cooling, heating and tap water preparation to buildings. The cold fluid side 101 may be coupled to a downhole heat exchanger, or borehole heat exchanger. For typical heating applications of the arrangement 100, the hot fluid side 102 may be a heating system, such as radiators or tap water systems, in the building. For typical cooling applications of the arrangement 100, the cold fluid side 101 may be a cooling system in the building. For typical cooling applications of the arrangement 100, the hot fluid side 102 may be an evolution of district heating and district cooling systems, where combined district heating and district cooling system with aid of using heat pumps for heating and cooling can provide both cooling, heating and tap water preparation to buildings. The hot fluid side 102 may be coupled to a downhole heat exchanger, or borehole heat exchanger.

The heat transfer arrangement 100 further comprises two heat pump modules 130a, 130b. It should however be noted that, although not illustrated, the heat transfer arrangement 100 may comprise more than two heat pump modules 130a, 130b. Each heat pump module 130a, 130b comprises first inlet and outlet ports 131a, 131 b and second inlet and outlet ports 132b, 132a. The first inlet and outlet ports 131a, 131 b are connected to the first inlet and outlet junction pipes 111 , 112, respectively. The second inlet and outlet ports 132b, 132a are connected to the second inlet and outlet junction pipes 122, 121 , respectively.

When the heat transfer arrangement 100 is in use, the two heat pump modules 130a, 130b are connected in parallel to each other. This is achieved by their respective first inlet and outlet ports 131a, 131 b which are connected to the first inlet and outlet junction pipes 111 , 112, respectively, and by their respective second inlet and outlet ports 132b, 132a which are connected to the second inlet and outlet junction pipes 122, 121 , respectively.

Each heat pump module 130a, 130b further comprises a refrigerant recirculation loop 134. The refrigerant recirculation loop 134 comprises a first heat exchanger unit 135 and a second heat exchanger unit 137 as well as a compressor 136 and an expander 138. The first heat exchanger unit 135 is fluidly connected to the first inlet and outlet ports 131a, 131b. Thus, the first heat exchanger 135 is connected to the first inlet and outlet junction pipes 111 , 112 via the first inlet and outlet ports 131a, 131 b, respectively. The second heat exchanger unit 137 is fluidly connected to the second inlet and outlet ports 132b, 132a. Thus, the second heat exchanger unit 137 is connected to the second inlet and outlet junction pipes 122, 121 via the second inlet and outlet ports 132b, 132a, respectively.

The refrigerant circulation loop 134 preferably circulates a refrigerant through the first heat exchanger unit 135, the compressor 136, the second heat exchanger unit 137 and the expander 138. In the first heat exchanger unit 135, the refrigerant and the cold side first fluid are configured to exchange thermal energy between each other such that a temperature of the refrigerant increases and a temperature of the cold side first fluid decreases thereby forming the cold side second fluid. Thus, the cold side first fluid and the cold side second fluid is typically the same fluid which has been supplied through the first heat exchanger unit 135 of the heat transfer arrangement 100, in which an exchange of thermal energy occurs between the cold side first fluid and the refrigerant.

The cold side second fluid is circulated in the cold side recirculation path 103 to the cold fluid side 101 . The refrigerant is circulated from the first heat exchanger unit 135 to the compressor 136 which is configured to increase the temperature and pressure of the refrigerant even further before supping the refrigerant to the second heat exchanger unit 137. In the second heat exchanger unit 137, the refrigerant and the hot side first fluid is configured to exchange thermal energy between each other such that a temperature of the refrigerant decreases and a temperature of the hot side first fluid increases thereby forming the hot side second fluid. Thus, the hot side first fluid and the hot side second fluid is typically the same fluid which has been supplied through a second heat exchanger unit 137 of the heat transfer arrangement 100, in which an exchange of thermal energy occurs between the hot side fluid and the refrigerant.

The hot side first fluid is circulated in the hot side recirculation path 104 to the hot fluid side 102. The refrigerant is circulated from the second heat exchanger unit 137 to the expander 138 which is configured to control an amount of refrigerant released into the first heat exchanger unit 135.

Each heat pump module 130a, 130b further comprising a control unit 133 and a memory 139. The control unit 133 is configured to control an operation of the associated heat pump module 130a, 130b. As depicted by the dotted line in figure 1 , the control unit 133 of each heat pump module 130a, 130b is connected to each other. The dotted line indicates a communication channel 140, i.e. that the control units 133 are connected to each other over the communication channel 140. The control units 133 may be wired, or wireless connected over the communication channel 140.

The memory 139 is configured to store heat pump module configuration information. The heat pump module configuration information may include identification data unique to the associated heat pump module 130a, 130b. The heat pump module configuration information may include heat pump module operational-specific data relating to the associated heat pump module 130a, 130b. The identification data may comprise an identity number, a serial number, a media access control, MAC, address and/or a Universal Unique Identifier, UUID. The heat pump module operational-specific data may comprise maximum input power and/or minimum input power and/or required cooling media relating to the associated heat pump module 130a, 130b. The memory 139 may be comprised in the associated control unit 133 or may, as illustrated, be arranged separately from, but in connection with, the associated control unit 133.

With reference to figure 2, a flowchart illustrating a method 200 for controlling an operation of a modular fluid-fluid heat transfer arrangement 100 by way of example. The modular fluid-fluid heat transfer arrangement 100 corresponds to the arrangement as introduced in connection with figure 1 .

The method 200 comprises a) transmitting, by the control unit 133 of each heat pump module 130a, 130b, associated heat pump module configuration information on the communication channel 140. Thereafter, the method 200 comprises b) receiving, by the control unit 133 of each heat pump module 130a, 130b, the associated heat pump module configuration information transmitted from each of the other heat pump modules 130a, 130b of the plurality of heat pump modules 130a, 130b. Thereafter, the method 200 comprises c) storing, on the memory 139 of each heat pump module 130a, 130b, the received heat pump module configuration information. By storing the associated heat pump module configuration information on the respective memory, each control unit 133 is configured to provide a heat transfer arrangement configuration information which includes the heat pump module configuration information of each heat pump module 130a, 130b. In step d), a master control unit is determined based on the heat transfer arrangement configuration information. The master control unit is selected from the control units 133 of the plurality of heat pump modules 130a, 130b. The one or more control units 133 that are different from the master control unit (i.e. the one or more control units 133 not being the master control unit) are defined as slave control units. In step e), the master control unit is configured to transmit operation control information to the slave control units.

The step d) of determining the master control unit may be based on associated identification data of the plurality of heat pump modules 130a, 130b as discussed in connection with figure 1 . The step d) of determining the master control unit may be based on the heat pump operational-specific data as discussed in connection with figure 1 .

Optionally, although not illustrated, the method 200 may comprise, prior to step d), determining a number of heat pump modules 130a, 130b connected over the communication channel 140. The operation control information to be transmitted by the master control unit may be based on the number of heat pump modules 130a, 130b connected over the communication channel 140.

Optionally, prior to step a), the method 200 may comprise connecting S206 the control units 133 to each other over the communication channel 140.

Optionally, prior to step a), the method 200 may comprise S207 starting a second timer. The second timer may be set to expire after a predetermined time period, e.g. five to ten minutes or any other suitable time period. The second timer is preferably set to expire after 1 to 60 minutes.

Optionally, prior to step d), the method 200 may comprise repeating the steps a) to c). The repeating the steps a) to c) may be performed a predefined number of times. The repeating the steps a) to c) may be performed during a predefined time period. If the second timer is started S207, the repeating the steps a) to c) may be performed until the second timer has expired S208. The repeating of the steps a) to c) may be performed in response to that heat transfer arrangement configuration information retrieved from at least two heat pump modules 130a, 130b are verified to be different.

Optionally, prior to step d), the method 200 may comprise performing a confirmation procedure in three steps f) to h) to verify if the heat transfer arrangement configuration information retrieved from at least two heat pump modules 130a, 130b are different. In step f), the control unit 133 of each heat pump module 130a, 130b is configured to transmit the heat transfer arrangement configuration information stored on the respective memory 139 on the communication channel 140. Thereafter, in step g), the control unit 133 of each heat pump module 130a, 130b is configured to receive the heat transfer arrangement configuration information transmitted from each of the other heat pump modules 130a, 130b. In step h), the received heat transfer arrangement configuration information is compared so as to verify that the heat transfer arrangement configuration information of all heat pump modules 130a, 130b are identical. The steps f) to h) may be performed in response to the heat pump modules 130a, 130b receiving a trigger signal.

If the heat transfer arrangement configuration information of all heat pump modules 130a, 130b are verified to be identical, the step d) may be provided.

If the heat transfer arrangement configuration information of all heat pump modules 130a, 130b are verified to be different, the timer, if present, may be reset and restarted and the repeating of the steps a) to c) may be performed once again in line with the above discussion.

The step a) of transmitting, by the control unit 133 of each heat pump module 130a, 130b, associated heat pump module configuration information on the communication channel 140 is preferably performed based on a communication protocol. The step f) of transmitting, by the control unit 133 of each heat pump module 130a, 130b, the heat transfer arrangement configuration information on the communication channel 140 is preferably performed based on a further communication protocol. The further communication protocol may be the same as the communication protocol used in step a) but may alternatively be different.

Even though illustrated and described in a certain order, other orders may also be used. The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments may be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

Claims

1 . A method (200) for controlling an operation of a modular fluid-fluid heat transfer arrangement (100), wherein the fluid-fluid heat transfer arrangement (100) comprises a plurality of heat pump modules (130a, 130b), each heat pump module (130a, 130b) comprising a control unit (133) and a memory (139), in which memory (139) heat pump module configuration information relating to the associated heat pump module (130a, 130b) is stored, said heat pump module configuration information including at least identification data unique to said associated heat pump module (130a, 130b), and wherein the control unit (133) of each heat pump module (130a, 130b) is connected to each control unit (133) of the other heat pump modules (130a, 130b) of the plurality of heat pump modules (130a, 130b) over a communication channel (140), the method (200) comprising: a) transmitting, by the control unit (133) of each heat pump module (130a, 130b), associated heat pump module configuration information on the communication channel (140); b) receiving, by the control unit (133) of each heat pump module (130a, 130b), the associated heat pump module configuration information transmitted from each of the other heat pump modules (130a, 130b) of the plurality of heat pump modules (130a, 130b); c) storing, on the memory (139) of each heat pump module (130a, 130b), said received heat pump module configuration information so as to provide in said memory (139) a heat transfer arrangement configuration information which includes the heat pump module configuration information of each heat pump module (130a, 130b) of the plurality of heat pump modules (130a, 130b); d) determining, based on the heat transfer arrangement configuration information, a master control unit selected from the control units (133) of the plurality of heat pump modules (130a, 130b), wherein the one or more control units (133) that are different from the master control unit are defined as slave control units; and e) transmitting operation control information from the master control unit to the slave control units.

2. The method (200) according to claim 1 , wherein the step a) of transmitting, by the control unit (133) of each heat pump module (130a, 130b), associated heat pump module configuration information on the communication channel (140) is performed based on a communication protocol.

3. The method (200) according to claim 1 or 2, further comprising determining a number of heat pump modules (130a, 130b) connected over the communication channel (140), and wherein the operation control information is based on the number of heat pump modules (130a, 130b).

4. The method (200) according to any one of the preceding claims, wherein, prior to the step d) of determining the master control unit, the method further comprises repeating the steps a) to c).

5. The method (200) according to claim 4, wherein the repeating of the steps a) to c) is performed a predefined number of times or repeatedly during a predefined time period.

6. The method (200) according to claim 4 or 5, wherein the repeating of the steps a) to c) is performed in response to that heat transfer arrangement configuration information retrieved from at least two heat pump modules (130a, 130b) are verified to be different.

7. The method (200) according to claim 6, wherein the verification is performed by: f) transmitting, by the control unit (133) of each heat pump module (130a, 130b), the heat transfer arrangement configuration information stored on the respective memory (139) on the communication channel (140); g) receiving, by the control unit (133) of each heat pump module (130a, 130b), the heat transfer arrangement configuration information transmitted from each of the other heat pump modules (130a, 130b); and h) comparing the received heat transfer arrangement configuration information so as to verify that the heat transfer arrangement configuration information of all heat pump modules (130a, 130b) is identical.

8. The method (200) according to claim 7, wherein the steps of claim 7 are performed in response to the heat pump modules (130a, 130b) receiving a trigger signal.

9. The method (200) according to any one of the preceding claims, wherein the identification data comprises an identity number, a serial number, a media access control, MAC, address and/or a Universal Unique Identifier, UUID.

10. The method (200) according to any one of the preceding claims, wherein the step d) of determining the master control unit is based on associated identification data of the plurality of heat pump modules (130a, 130b).

11 . The method (200) according to any one of the preceding claims, wherein the heat pump module configuration information further comprises heat pump module operational-specific data relating to the associated heat pump module (130a, 130b).

12. The method (200) according to claim 11 , wherein the step d) of determining the master control unit is based on said heat pump operational- specific data.

13. A modular fluid-fluid heat transfer arrangement (100) comprising a plurality of heat pump modules (130a, 130b), each heat pump module (130a, 130b) comprising a control unit (133) and a memory (139), in which memory (139) heat pump module configuration information relating to the associated heat pump module (130a, 130b) is stored, said heat pump module configuration information including at least identification data unique to said associated heat pump module (130a, 130b), and wherein the control unit (133) of each heat pump module (130a, 130b) is connected to each control unit (133) of the other heat pump modules (130a, 130b) over a communication channel (140), the control unit (133) of each heat pump module (130a, 130b) being configured to: transmit associated heat pump module configuration information on the communication channel (140); receive the associated heat pump module configuration information transmitted from each of the other heat pump modules (130a, 130b); store, on the memory (139) of the associated heat pump module (130a, 130b), said received heat pump module configuration information so as to provide in said memory (139) a heat transfer arrangement configuration information which includes the heat pump module configuration information of each heat pump module (130a, 130b) of the arrangement (100); and determine, based on the heat transfer arrangement configuration information, a master control unit selected from the control units (133) of the plurality of heat pump modules (130a, 130b), wherein the one or more control units (133) that are different from the master control unit are defined as slave control units; wherein the determined master control unit is configured to transmit operation control information to the slave control units.

14. The modular fluid-fluid heat transfer arrangement (100) according to claim 13, wherein the slave control unit of each heat pump module (130a, 130b) is further configured to control the operation of the associated heat pump module (130a, 130b) based on the operation control information received from the master control unit.

15. The modular fluid-fluid heat transfer arrangement (100) according to claim 13 or 14, wherein the control unit (133) of each heat pump module (130a, 130b) is wired or wirelessly connected to the control unit (133) of the other heat pump modules (130a, 130b) via the communication channel (140).