Arrangement for the use of building exhaust air for cooling and / or heating and system for heating and / or cooling of the building

Abstract

The arrangement for the use of building exhaust air for cooling and / or heating (100) comprises a chamber divided into a first portion (101) and a second portion (102), at least one evaporator / condenser (103) arranged in the chamber and configured to pass the exhaust air from the first portion (101) into the second portion (102) to transfer heat from the exhaust air to a refrigerant or from the refrigerant to the exhaust air, at least one exhaust air inlet (104) for introducing the exhaust air into the first portion of the chamber (101), at least one evaporator / condenser fan (105) for controlling flow of air through said at least one evaporator / condenser (103), at least one exhaust air outlet (106) for discharging air from the second portion of the chamber (102), and at least one fresh air inlet (107) for introducing ambient air into the exhaust air upstream from said at least one evaporator / condenser (103).

Description

Technical field

[0001] The present invention relates to an arrangement for the use of building exhaust air for cooling and / or heating. The invention also relates to a system for heating and / or cooling of the building.Background of the invention

[0002] In current building cooling and heating systems, heat recovery is typically carried out through ventilation machines, utilizing techniques such as glycol recovery, cross- and counter-flow recovery, rotary heat recovery, and recirculated air recovery. Cooling systems are usually indirectly connected to the recovery process, preventing them from directly utilizing the cooling energy recovered from the building. Often, cooling units are placed outside the building, using outdoor air for condensation in the cooling compressors, without taking advantage of the cooled exhaust air from inside the building.

[0003] Passive cooling recovery achieved through ventilation machines is often inefficient due to the relatively small temperature difference between the exhaust air being removed and the outdoor air being brought in. This small temperature differential (ΔT) limits the efficiency of recovery. Moreover, in exhaust air ventilation, the energy from cooling is completely wasted, as it is expelled as exhaust air through roof fans.

[0004] In Finland, many residential buildings operate with exhaust air ventilation, without any form of cooling or heating energy recovery. Heat recovery solutions developed for exhaust ventilation focus mainly on recovering the energy from the exhaust air expelled from the building. During the cooling season, these solutions are either completely out of use or used very minimally, as the building does not require heating energy.Objectives of the invention

[0005] It is the main objective of the present invention to reduce or even eliminate the prior art problems presented above.

[0006] It is an objective of the present invention to provide an energy-efficient production and recovery of cooling and heating energy. The invention enables to combine both techniques into one arrangement, which differs from previous traditional solutions. The advantage of this is the efficiency of the arrangement. The objective of the invention is to achieve an arrangement that utilizes the energy obtained from the exhaust air, thus achieving both energy savings and reducing environmental impacts.

[0007] It is a further objective of the present invention to provide also an arrangement that, in addition to heat recovery, can also utilize cooling energy recovery. The present invention enables that heat recovery solutions developed for exhaust air exchange can also be utilized throughout the year. This is achieved by allowing the energy obtained from the exhaust air to be utilized both during heating and cooling. In previous arrangements heat recovery solutions developed for exhaust air exchange have mainly focused on energy recovery from the exhaust air removed from the building, and they are therefore completely out of use outside the heating season, i.e., in the summer.

[0008] The objective of the present invention is also to develop a system that utilizes the arrangement and enables the distribution of the produced cooling and heating energy to the building with traditional heating radiators and cooling beam networks or with a fan coil network that combines both functions. This provides a novel, efficient, and environmentally friendly solution for the energy management in buildings.

[0009] In order to realise the above-mentioned objectives, the arrangement and system according to the invention are characterised by what is presented in the appended independent claims. Advantageous embodiments of the invention are described in the dependent claims.Summary of the invention

[0010] An object of the invention is to provide an improved arrangement for the use of building exhaust air for cooling and / or heating. Another object of the invention is to provide a system using the arrangement for the use of building exhaust air for cooling and / or heating.

[0011] The arrangement according to the invention for the use of building exhaust air for cooling and / or heating comprises a chamber divided into a first portion and a second portion, at least one evaporator / condenser arranged in the chamber and configured to pass the exhaust air from the first portion into the second portion to transfer heat from the exhaust air to a refrigerant or from the refrigerant to the exhaust air, at least one exhaust air inlet for introducing the exhaust air into the first portion of the chamber, at least one evaporator / condenser fan for controlling flow of air through said at least one evaporator / condenser, at least one exhaust air outlet for discharging air from the second portion of the chamber, and at least one fresh air inlet for introducing ambient air into the exhaust air upstream from said at least one evaporator / condenser.

[0012] The arrangement according to the invention makes it possible to integrate the production and recovery of cooling and heating energy into single centralised technology, reducing the investment cost and overall energy consumption of the ventilation system in buildings. The arrangement according to the invention also helps to reduce the space needed for ventilation, cooling and heating systems.

[0013] The arrangement according to the invention enables the recovery of cooling and heating energy by recirculating the cooling air or exhaust air containing heat energy in a chamber without indirect energy recovery. The building exhaust air is supplied through a dual-function evaporator / condenser, wherein pressure conditions enable the removal of excess pressure via the exhaust air outlet in case of overpressure, or increase the amount of air from the outside via the fresh air inlet in case of underpressure.

[0014] According to an embodiment of the invention, the arrangement comprises at least one bypass opening and a closure element having an open position and a closed position, wherein in the open position of the closure element air flow via the bypass opening between the first portion and the second portion of the chamber is allowed and in the closed position of the closure element air flow via the bypass opening between the first portion and the second portion is prevented. The bypass opening allows air flow between the two portions of the dividing chamber and thus enables recovery of the cooling and heating energy. Recirculating of the cooling and heating energy increases the energy efficiency of the arrangement.

[0015] According to an embodiment of the invention, the arrangement comprises an actuator for closing and opening the closure element. The actuator can be operated electrically or manually and allows easy selection of the appropriate mode of operation.

[0016] According to an embodiment of the invention, the arrangement comprises a control unit for controlling the actuator. The control unit further increases the ease of use and selection of the mode of operation thus enabling, for example, the use of automation.

[0017] According to an embodiment of the invention, the arrangement has three different modes of operation depending on the current cooling or heating need of the building. The modes of operations are presented below.

[0018] According to an embodiment of the invention, the arrangement has a cooling mode for cooling the building, and in the cooling mode the closure element is in the closed position. The cooling mode as one of the modes of operations extends the exploitation time of the arrangement to the whole year. Normally there is for cooling of the building a separate system, which is unused for most of the year.

[0019] According to an embodiment of the invention, the arrangement has a heat recovery mode for the heat recovery of the building, and in the heat recovery mode the closure element is in the open position to allow backflow from the second portion into the first portion of the chamber. The heat mode also allows for the utilisation of the arrangement throughout the entire year. Both the heat mode and the cooling mode offer the potential for energy savings, cost savings and space savings.

[0020] According to an embodiment of the invention, the arrangement has an air throughflow mode and in the air throughflow mode the closure element is in the open position to allow air flow from the first portion into the second portion of the chamber via the bypass opening. The throughflow mode allows ventilation to continue even in the event of a power failure or equipment failure, thereby increasing the reliability of the arrangement and preventing potential challenges to ventilation in the event of a power failure or equipment failure.

[0021] According to an embodiment of the invention, the fresh air inlet is configured to open when the pressure in the first portion of the chamber is below the ambient pressure and to close when the pressure in the first portion is above the ambient pressure.

[0022] The arrangement according to the invention controls the pressure conditions by dividing the chamber into positive and negative pressure portions, compared to the ambient pressure. The pressure conditions enable complete recovery of cooling energy and removal of condensation heat generated by the cooling process from the chamber by the positive pressure generated by the evaporator / condenser in the cooling mode. The additional air required for cooling is specifically introduced from the fresh air inlet to the chamber by the underpressure produced by the evaporator / condenser. Thereby the fresh air inlet increases the efficiency of the arrangement and allows the pressure required for operation to be equalised. When in heating mode, the heating energy is maximised and the cooled energy deficient residual air is removed to the outside air via the exhaust air outlet by overpressure.

[0023] According to an embodiment of the invention, the arrangement comprises two exhaust air outlets and / or two fresh air inlets. By doubling the number of the exhaust air outlets and the fresh air inlets, sufficient air exchange can be ensured thus ensuring the correct formation of pressure differences, which are important for efficient operation of the arrangement.

[0024] According to an embodiment of the invention, the arrangement comprises an exhaust fan for supplying the exhaust air to the first portion of the chamber. The exhaust air fan allows the arrangement to receive waste air from the building and use the energy from the waste air, thus increasing the energy efficiency of the arrangement.

[0025] According to an embodiment of the invention, the arrangement comprises a heat exchanger for transferring heat into a heat distribution circuit of a building and, optionally, out of a cooling circuit of the building, a refrigerant circuit for circulating refrigerant between the evaporator / condenser and the heat exchanger, and a compressor for pressurising the refrigerant in the refrigerant circuit.

[0026] The system according to the invention for heating and / or cooling of a building comprises the arrangement defined above, and a heat distribution circuit comprising at least one heating element and a pump for circulating heat transfer medium in the heat distribution circuit, the heat distribution circuit being configured to receive heat from the heat exchanger.

[0027] According to an embodiment of the invention, the system comprises a buffer tank arranged as part of the heat distribution circuit. The buffer tank helps to optimise heat production, store excess heat and balance temperatures and pressures in the heat distribution circuit.

[0028] According to an embodiment of the invention, the system comprises a cooling circuit comprising at least one cooling element and a pump for circulating heat transfer medium in the cooling circuit, the cooling circuit being configured to transfer heat to the heat exchanger.

[0029] According to an embodiment of the invention, the heating and the cooling element transfers the heating or the cooling energy from the arrangement to the building, thereby achieving the desired indoor temperature.Brief description of the drawings

[0030] The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. Fig. 1Shows a diagram of the arrangement for the use of building exhaust air for cooling and / or heating, and Fig. 2shows a diagram of the system for heating and / or cooling of a building. Detailed description of embodiments of the invention

[0031] Figure 1 is shows an arrangement 100 for the use of building 120 exhaust air for cooling and / or heating. The arrangement 100 can be connected as part of a building's 120 ventilation system to use the exhaust air for heating and cooling the building 120. The arrangement 100 can be used in many different buildings 120. The building can be a residential building, such as a block of flats, a commercial property or a hall, for example. The arrangement 100 can be used in any of building equipped with a mechanical ventilation system. The arrangement is best suited for buildings having a volume of at least 1500 m 3< .

[0032] The arrangement 100 comprises a chamber. The chamber is an airtight and tank-like part, where air flows are processed to enable the arrangement to function. The chamber is divided into two separate portions, a first portion 101 and a second portion 102.

[0033] The building's 120 mechanical ventilation system has at least one exhaust air fan 112. The exhaust fan 112 of the building's ventilation system supplies air to the arrangement 100. The arrangement is connected to the building's ventilation system via an exhaust air inlet 104, through which the building's exhaust air flows into the arrangement 100. The exhaust air inlet 104 is connected to the first portion 101 of the chamber. The arrangement may have one, two or more exhaust air inlets 104.

[0034] The arrangement 100 comprises at least one evaporator / condenser 103. The evaporator / condenser 103 is arranged in the chamber and it is configured to pass the exhaust air from the first portion 101 of the chamber into the second portion 102 of the chamber. The evaporator / condenser 103 transfers heat from the exhaust air to a refrigerant or from the refrigerant to the exhaust air depending on whether the building is being heated or cooled. There may be one, two or more evaporator / condensers 103. If there are several evaporator / condensers 103, they can be placed symmetrically and parallel.

[0035] The arrangement 100 comprises also at least one evaporator / condenser fan 105. The evaporator / condenser fan 105 is configured to control flow of air through the evaporator / condenser 103. The evaporator / condenser fan 105 is arranged in connection with the evaporator / condenser 103. In the embodiment of the figures, one evaporator / condenser fan 105 is connected to the evaporator / condenser 103. There may be one, two or more the evaporator / condenser fans 105, and if there are more than one the evaporator / condenser fans 105, they can be placed symmetrically and parallel.

[0036] The arrangement 100 comprises at least one exhaust air outlet 106. In the embodiment of figure 1, the arrangement 100 comprises two exhaust air outlets 106, but there may be one, two or more the exhaust air outlets 106, depending on the needs of the building 120. The exhaust air outlet 106 is in the wall of the second portion 102 of the chamber and it is configured to discharge air from the second portion 102 of the chamber.

[0037] The arrangement 100 further comprises at least one fresh air inlet 107. According to an embodiment of the invention, the arrangement 100 comprises two fresh air inlets 107, but there may be one or more than two fresh air inlets 107. The fresh air inlet 107 is arranged upstream or downstream of an exhaust fan 112 and it is intended to introduce ambient air into the exhaust air upstream from the evaporator / condenser 103. The fresh air inlet 107 may be a self-regulating inlet, which may comprise, for example, a valve or flap. The fresh air inlet 107 is configured to open and close depending on pressure. The fresh air inlet 107 is configured to open if the pressure in the first portion 101 of the chamber is below the ambient pressure and configured to close when the pressure in the first portion 101 is above the ambient pressure.

[0038] According to an embodiment of the invention, the arrangement 100 comprises at least one bypass opening 108 and a closure element 109. There can be one or more bypass openings 108 and closure elements 109. If there are several bypass openings 108 and closure elements 109, they can be placed symmetrically about the evaporator / condenser 103. The bypass opening 108 and the closure element 109 is located between the first 101 and the second portion 102 of the chamber to allow air flow between the two portions of the chamber.

[0039] The closure element 109 has an open position and a closed position. In the closed position of the closure element 109, air flow via the bypass opening 108 is prevented. The closure element 109 can be a flat part such as a plate or a flap.

[0040] The position of the closure element 109 can be changed by an actuator 110 which is configured to close and open the closure element 109. The actuator 110 may be manual or electrically or pneumatically controlled. The arrangement 100 can comprise a control unit 111 for controlling the actuator 110. The closure element 109 comprises a means for transmitting the transmission force from the actuator 110 to the closure element 109. The means of closing and opening may, for example, be a shaft. The closure element 109 is preferably attached to the shaft, for example by welding. In the open position of the closure element 109, air flow is allowed via the bypass opening 108 between the first portion 101 and the second portion 102 of the chamber. In the closed position of the closure element 109 air flow is prevented via the bypass opening 108 between the first portion 101 and the second portion 102 of the chamber.

[0041] The arrangement 100 for the use of building exhaust air for cooling and / or heating may have different operating modes. The arrangement may have three operating modes. The modes can be a cooling mode, a heat recovery mode and an air throughflow mode. The position of the closure element 109 can be determined according to the operating mode that is currently in use. The cooling mode is on, when cooling of the building is needed and in the cooling mode the closure element 109 can be in the closed position to prevent air flow from the second portion 102 of the chamber to the first portion 101 of the chamber. The heat recovery mode is used when the building is heated. In the heat recovery mode the closure element 109 can be in the open position to thus allow air backflow from the second portion 102 into the first portion 101 of the chamber. The air throughflow mode can be activated, for example, in the event of a power failure or a stoppage of the system. In the air throughflow mode the closure element 109 is in the open position to allow air flow between the first portion 101 and the second portion 102 of the chamber via the bypass opening 108.

[0042] According to an embodiment of the invention, the arrangement comprises a heat exchanger 113, a refrigerant circuit 119 and a compressor 114. The heat exchanger 113 is configured to transfer heat from the refrigerant circuit 119 to a heat distribution circuit 116 of a building 120 and, optionally, from a cooling circuit 116 of the building 120 to the refrigerant circuit 119. The refrigerant circuit 119 is configured to circulate refrigerant between the evaporator / condenser 103 and the heat exchanger 113 and the compressor 114 is configured to pressurise the refrigerant in the refrigerant circuit 119.

[0043] Figure 2 shows a system 200 according to the invention for heating of a building 120. The system comprises the arrangement 100 set out above. The system further comprises a heat distribution circuit 116 having at least one heating element 117. The heating elements 117 may be, for example, hydronic radiators, hydronic underfloor heating or hydronic fan coil units. There may be one or more heating elements 117, depending on the requirements of the building 120.

[0044] The system 200 may comprise also a buffer tank 118. The buffer tank 118 can be a cylindrical, airtight tank that is well insulated to prevent heat loss. The buffer tank 118 is connected to the heat distribution circuit 116. The buffer tank 118 is configurated to compensate heat and pressure variations.

[0045] The system 200 comprises at least one pump 115 to circulate the heat transfer medium in the heat distribution circuit 116. The number of the pumps 115 also depends on the requirements of the building 120 and there may be one or more pumps 115 in the system. The heat distribution circuit 116 is configured to receive heat from the refrigerant circuit 119 via the heat exchanger 113.

[0046] The system 200 for cooling of the building 120 according to the invention comprises the arrangement 100 set out above. The system 200 further comprises a cooling circuit 116 with at least one cooling element 117. The cooling elements 117 may be, for example, AC units, fan coil units or chilled beams. There may be one or more cooling elements 117, depending on the requirements of the building 120. The system 200 also comprises a pump 115 to circulate the heat transfer medium in the cooling circuit 116. The number of the pumps 115 also depends on the requirements of the building 120, and there may be one or more pumps 115 in the system. The cooling circuit 116 is configured to transfer heat via the heat exchanger 113 to the refrigerant circuit 119.

Claims

1. An arrangement for the use of building exhaust air for cooling and / or heating (100), the arrangement comprising: - a chamber divided into a first portion (101) and a second portion (102), - at least one evaporator / condenser (103) arranged in the chamber and configured to pass the exhaust air from the first portion (101) into the second portion (102) to transfer heat from the exhaust air to a refrigerant or from the refrigerant to the exhaust air, - at least one exhaust air inlet (104) for introducing the exhaust air into the first portion of the chamber (101), - at least one evaporator / condenser fan (105) for controlling flow of air through said at least one evaporator / condenser (103), - at least one exhaust air outlet (106) for discharging air from the second portion of the chamber (102), and - at least one fresh air inlet (107) for introducing ambient air into the exhaust air upstream from said at least one evaporator / condenser (103).

2. The arrangement for the use of building exhaust air for cooling and / or heating according to claim 1, comprising at least one bypass opening (108) and a closure element (109) having an open position and a closed position, wherein in the open position of the closure element (109) air flow via the bypass opening (108) between the first portion (101) and the second portion (102) of the chamber is allowed and in the closed position of the closure element (109) air flow via the bypass opening (108) between the first portion (101) and the second portion (102) is prevented.

3. The arrangement for the use of building exhaust air for cooling and / or heating according to claim 1 or 2, comprising an actuator (110) for closing and opening the closure element (109).

4. The arrangement for the use of building exhaust air for cooling and / or heating according to claim 3, comprising a control unit (111) for controlling the actuator (110).

5. The arrangement for the use of building exhaust air for cooling and / or heating according to any of claims 2-4, wherein the arrangement has a cooling mode for cooling the building, and in the cooling mode the closure element (109) is in the closed position.

6. The arrangement for the use of building exhaust air for cooling and / or heating according to any of claims 2-5, wherein the arrangement has a heat recovery mode for the heat recovery of the building, and in the heat recovery mode the closure element (109) is in the open position to allow backflow from the second portion (102) into the first portion (101) of the chamber.

7. The arrangement for the use of building exhaust air for cooling and / or heating according to any of claims 2-6, wherein the arrangement has an air throughflow mode and in the air throughflow mode the closure element (109) is in the open position to allow air flow from the first portion (101) into the second portion (102) of the chamber via the bypass opening (108).

8. The arrangement for the use of building exhaust air for cooling and / or heating according to any of the preceding claims, wherein the fresh air inlet (107) is configured to open when the pressure in the first portion (101) of the chamber is below the ambient pressure and to close when the pressure in the first portion (101) is above the ambient pressure.

9. The arrangement for the use of building exhaust air for cooling and / or heating according to any of the preceding claims, wherein the arrangement comprises two exhaust air outlets (106) and / or two fresh air inlets (107).

10. The arrangement for the use of building exhaust air for cooling and / or heating according to any of the preceding claims, comprising an exhaust fan (112) for supplying the exhaust air to the first portion (101) of the chamber.

11. The arrangement for the use of building exhaust air for cooling and / or heating according to any of the preceding claims, comprising a heat exchanger (113) for transferring heat into a heat distribution circuit (116) of a building (120) and, optionally, out of a cooling circuit of the building (120), a refrigerant circuit (119) for circulating refrigerant between the evaporator / condenser (103) and the heat exchanger (113), and a compressor (114) for pressurising the refrigerant in the refrigerant circuit (119).

12. A system for heating and / or cooling of a building (120), the system comprising - the arrangement according to claim 11, and - a heat distribution circuit (116) comprising at least one heating element (117) and a pump (115) for circulating heat transfer medium in the heat distribution circuit, the heat distribution circuit being configured to receive heat from the heat exchanger (113).

13. A system for heating and / or cooling of a building (120), the system comprising a buffer tank (118) arranged as part of the heat distribution circuit (116).

14. The system for heating and / or cooling of the building according to claim 13, the system comprising a cooling circuit comprising at least one cooling element and a pump (115) for circulating heat transfer medium in the cooling circuit, the cooling circuit being configured to transfer heat to the heat exchanger.

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