A heat recovery double cold source medium temperature air conditioning system for low temperature air supply

Abstract

This utility model discloses a heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply, comprising a heat recovery dual-source medium-temperature air conditioning unit, a direct expansion section outdoor unit, a heat recovery exhaust fan box, an exhaust fan unit, and a solution circulation pump. The heat recovery dual-source medium-temperature air conditioning unit is connected to the direct expansion section outdoor unit. The heat recovery dual-source medium-temperature air conditioning unit sequentially includes an air inlet section, a first coarse filter section, a solution circulation heat recovery section, a mixing section, a second coarse filter section, a high-efficiency filter section, an air conditioning water-cooled coil section, a medium-temperature direct expansion refrigeration section, a condenser reheat section, an air conditioning maintenance section, and a fan supply section. The heat recovery dual-source medium-temperature air conditioning unit is connected to the medium-temperature air-conditioned area via a return air duct and a supply air duct. The heat recovery exhaust fan box sequentially includes an air inlet section, a third coarse filter section, an air conditioning maintenance section, a solution circulation heat recovery section, and a fan section. The heat recovery exhaust fan box is connected to the medium-temperature air-conditioned area via an exhaust duct.

Description

Technical Field

[0001] This utility model belongs to the field of low-temperature air supply air treatment technology, specifically relating to a heat recovery dual-cold-source medium-temperature air conditioning system for low-temperature air supply. Background Technology

[0002] Airline food production is a complex process, encompassing raw material procurement and storage, raw material processing, meal preparation, assembly and arrangement, transport and loading onto aircraft, and in-flight catering services. Airline food hygiene standards require that the processing time for food packaging, assembly, and preparation be controlled based on the ambient temperature. Combined with the processing techniques of the airline catering company, the food production area must maintain a constant environment of 13-15℃, hereinafter referred to as the medium-temperature workshop. The food production area includes the main display area, hot display area, cold kitchen, cake decorating and packaging area, in-flight catering area, and cold dish preparation area. General comfort air conditioning systems, due to their high supply air temperatures, cannot meet these process requirements. Therefore, air conditioning systems designed for the medium-temperature zone have emerged, requiring lower supply air temperatures to meet these process requirements. Furthermore, existing air conditioning equipment has relatively limited functionality, lacking heat recovery and dual-source switching capabilities, resulting in resource waste and poor energy efficiency. Utility Model Content

[0003] The purpose of this invention is to solve the above problems and provide a heat recovery dual-cold source medium-temperature air conditioning system that can achieve low-temperature air supply, maintain a constant environment in the food production area, and flexibly switch between heat recovery and dual-cold source operation according to different operating seasons, thereby achieving effective energy saving through heat recovery and dual-cold source operation.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is: a medium-temperature air conditioning system with heat recovery dual cold source for low-temperature air supply, comprising a medium-temperature air conditioning unit with heat recovery dual cold source, an outdoor unit with direct expansion section, an exhaust fan box with heat recovery, an exhaust fan unit, and a solution circulation pump. The medium-temperature air conditioning unit with heat recovery dual cold source is connected to the outdoor unit with direct expansion section. The medium-temperature air conditioning unit with heat recovery dual cold source is provided with an air inlet section, a first coarse filter section, a solution circulation heat recovery section, a mixing section, a second coarse filter section, a high-efficiency filter section, and an air conditioning water-cooled coil in sequence. The unit consists of a medium-temperature direct expansion refrigeration section, a condensing reheat section, an air conditioning maintenance section, and a fan supply section. The medium-temperature air conditioning unit with heat recovery dual cold source is connected to the medium-temperature air-conditioned area through return air ducts and supply air ducts. The exhaust fan box with heat recovery is equipped with a second air inlet section, a third coarse filter section, a second air conditioning maintenance section, a second solution circulation heat recovery section, and a fan section in sequence. The exhaust fan box with heat recovery is connected to the medium-temperature air-conditioned area through an exhaust duct. The exhaust fan box with heat recovery is connected to the medium-temperature air conditioning unit with heat recovery dual cold source through a pipeline, and a solution circulation pump is installed on the pipeline.

[0005] Preferably, a fresh air duct is connected to the air inlet section, a first electric air volume regulating valve is provided between the fresh air duct and the air inlet section, a fresh air bypass pipe is provided on the fresh air duct, a second electric air volume regulating valve is provided on the fresh air bypass pipe, a third electric air volume regulating valve is provided on the return air duct, a first electric second ventilation valve is provided between the exhaust fan box with heat recovery and the exhaust duct, and a second electric second ventilation valve is provided between the exhaust fan unit and the exhaust duct.

[0006] Preferably, the medium-temperature direct expansion refrigeration section and the condensing reheat section of the dual-source medium-temperature air conditioning unit with heat recovery are connected to the outdoor unit of the direct expansion section through refrigerant pipes; the solution circulation heat recovery section of the dual-source medium-temperature air conditioning unit with heat recovery is connected to the second solution circulation heat recovery section in the exhaust fan box with heat recovery and to the solution circulation pump through a solution circulation pipe.

[0007] Preferably, the air conditioning water-cooled coil section of the dual-cold-source medium-temperature air conditioning unit with heat recovery is connected to the centralized air conditioning chilled water supply equipment through air conditioning supply and return water pipes to perform primary cooling treatment on the air.

[0008] Preferably, the air inlet section, the first coarse filter section, the solution circulation heat recovery section, the air mixing section, the second coarse filter section, the high-efficiency filter section, the air conditioning water-cooled coil section, the medium-temperature direct expansion refrigeration section, the condenser reheat section, the air section maintenance section, and the fan air supply section of the dual-cold-source medium-temperature air conditioning unit with heat recovery are arranged in sequence, so that the air can pass through each section in sequence and finally be output through the fan air supply section.

[0009] Preferably, the fresh air bypass pipe is connected to the return air pipe.

[0010] Preferably, the medium-temperature air-conditioned area is supplied with air through a supply air duct, returned with air through a return air duct, and exhausted with air through an exhaust air duct, thereby forming a complete air handling and air circulation system.

[0011] The beneficial effects of this utility model are:

[0012] 1. This utility model provides a heat recovery dual-cold-source medium-temperature air conditioning system for low-temperature air supply, which can achieve low-temperature air supply and maintain a constant environment of 13-15℃ in the food production area. Simultaneously, this air conditioning system flexibly switches between heat recovery and dual-cold-source operation modes according to different operating seasons, achieving effective energy saving through heat recovery and dual-cold-source utilization. This is to effectively ensure the quality of aviation food, production efficiency, and personnel health, while achieving energy-saving goals.

[0013] 2. This utility model has the ability to recover heat by utilizing the large temperature difference between the indoor and outdoor areas of a medium-temperature workshop, which has energy-saving benefits.

[0014] 3. This utility model adopts dual cold source secondary cooling technology to achieve low-temperature air supply in air conditioning, which solves the technical problem that conventional air conditioners cannot achieve low-temperature air supply.

[0015] 4. The opening and closing of the ventilation damper and the switching of the exhaust fan of this utility model can realize the activation and deactivation of heat recovery, thereby enabling the air conditioning system to flexibly switch between heat recovery, dual cold source and other operating conditions according to different operating seasons. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a heat recovery dual-cold-source medium-temperature air conditioning system for low-temperature air supply according to this utility model;

[0017] Figure 2 This is a schematic diagram of the operating principle of the air handling heat recovery system of the dual-cold-source medium-temperature air conditioning unit with heat recovery when it is turned on.

[0018] Figure 3 This is a schematic diagram of the principle of the air handling heat recovery shutdown of the dual-cold-source medium-temperature air conditioning unit with heat recovery of this utility model.

[0019] Explanation of reference numerals in the attached diagram: 1. Medium-temperature air conditioning unit with dual cooling sources and heat recovery; 2. Outdoor unit of direct expansion section; 3. Exhaust fan box with heat recovery; 4. Exhaust fan unit; 5. Solution circulation pump; 6. Return air duct; 7. Supply air duct; 8. Medium-temperature air-conditioned area; 9. Exhaust air duct; 10. Air inlet section; 11. First coarse filter section; 12. Solution circulation heat recovery section; 13. Mixing section; 14. Second coarse filter section; 15. High-efficiency filter section; 16. Air conditioning water-cooled coil section; 17. Medium-temperature direct expansion section. Refrigeration section; 18. Condensation and reheat section; 19. Air supply and maintenance section; 20. Fan supply section; 30. Second air inlet section; 31. Third coarse filtration section; 32. Air supply and maintenance section; 33. Second solution circulation heat recovery section; 34. Fan section; 100. Fresh air duct; 101. Fresh air bypass duct; V1. First electric air volume regulating valve; V2. Second electric air volume regulating valve; V3. Third electric air volume regulating valve; V4. First electric second ventilation valve; V5. Second electric second ventilation valve. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0021] like Figures 1 to 3As shown, this utility model provides a heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply, including a heat recovery dual-source medium-temperature air conditioning unit 1, a direct expansion section outdoor unit 2, a heat recovery exhaust fan box 3, an exhaust fan unit 4, and a solution circulation pump 5. The heat recovery dual-source medium-temperature air conditioning unit 1 is connected to the direct expansion section outdoor unit 2. The heat recovery dual-source medium-temperature air conditioning unit 1 is provided with an air inlet section 10, a first coarse filter section 11, a solution circulation heat recovery section 12, a mixing section 13, a second coarse filter section 14, a high-efficiency filter section 15, an air conditioning water-cooled coil section 16, a medium-temperature direct expansion cooling section 17, a condenser reheat section 18, an air conditioning maintenance section 19, and a fan supply section 20. The heat recovery dual-source medium-temperature air conditioning unit 1 is connected to the medium-temperature air-conditioned area 8 through a return air duct 6 and a supply air duct 7. The heat recovery exhaust fan box 3 is sequentially equipped with a second air inlet section 30, a third coarse filter section 31, a second air maintenance section 32, a second solution circulation heat recovery section 33, and a fan section 34. The heat recovery exhaust fan box 3 is connected to the medium-temperature air-conditioned area 8 via an exhaust pipe 9. The heat recovery exhaust fan box 3 is connected to the heat recovery dual-source medium-temperature air-conditioned unit 1 via a pipeline, on which a solution circulation pump 5 is installed.

[0022] The air conditioning water-cooled coil section 16 of the dual-source medium-temperature air conditioning unit 1 with heat recovery is connected to the centralized air conditioning chilled water supply equipment through air conditioning supply and return water pipes to perform primary cooling of the air. The centralized air conditioning chilled water supply equipment is an existing water supply equipment, with a supply water temperature of 7°C and a return water temperature of 12°C. In this embodiment, any existing centralized cold source equipment capable of providing chilled water at 7-12°C can be used. The air inlet section 10, the first coarse filter section 11, the solution circulation heat recovery section 12, the air mixing section 13, the second coarse filter section 14, the high-efficiency filter section 15, the air conditioning water-cooled coil section 16, the medium-temperature direct expansion refrigeration section 17, the condenser reheat section 18, the air section maintenance section 19, the fan air supply section 20, the second air inlet section 30, the third coarse filter section 31, the second air section maintenance section 32, the second solution circulation heat recovery section 33, and the fan section 34 are all technical names in the art.

[0023] In this embodiment, the medium-temperature air-conditioned area is an existing enclosed space, such as an existing medium-temperature workshop. The internal temperature is regulated and maintained between 13 and 15°C by a medium-temperature air-conditioning unit 1 with heat recovery dual cold source, an outdoor unit 2 with direct expansion section, an exhaust fan box 3 with heat recovery, supply air ducts, and return air ducts.

[0024] A fresh air duct 100 is connected to the air inlet section 10. A first electric air volume regulating valve V1 is provided between the fresh air duct 100 and the air inlet section 10. A fresh air bypass pipe 101 is provided on the fresh air duct 100. A second electric air volume regulating valve V2 is provided on the fresh air bypass pipe 101. A third electric air volume regulating valve V3 is provided on the return air duct 6. A first electric second ventilation valve V4 is provided between the heat recovery exhaust fan box 3 and the exhaust pipe 9. A second electric second ventilation valve V5 is provided between the exhaust fan unit 4 and the exhaust pipe.

[0025] The first electric air volume regulating valve V1, the second electric air volume regulating valve V2, and the third electric air volume regulating valve V3 are all electric air volume regulating valves. By adjusting the opening and closing of the first electric air volume regulating valve V1, the second electric air volume regulating valve V2, and the third electric air volume regulating valve V3, the on / off state of the pipeline is adjusted.

[0026] The first electric secondary ventilation valve V4 and the second electric secondary ventilation valve V5 are both electric secondary ventilation valves. By controlling the opening and closing of the first electric secondary ventilation valve V4 and the second electric secondary ventilation valve V5, the exhaust function can be achieved.

[0027] The medium-temperature direct expansion refrigeration section 17 and the condensing reheat section 18 of the dual-source medium-temperature air conditioning unit 1 with heat recovery are connected to the outdoor unit 2 of the direct expansion section via refrigerant pipes. The solution circulation heat recovery section 12 of the dual-source medium-temperature air conditioning unit 1 with heat recovery is connected to the second solution circulation heat recovery section 33 in the exhaust fan box 3 with heat recovery and is connected to the solution circulation pump 5 via a solution circulation pipe.

[0028] The air inlet section 10, the first coarse filter section 11, the solution circulation heat recovery section 12, the mixing section 13, the second coarse filter section 14, the high-efficiency filter section 15, the air conditioning water-cooled coil section 16, the medium-temperature direct expansion refrigeration section 17, the condensing reheat section 18, the air section maintenance section 19, and the fan air supply section 20 are arranged in sequence. The air can pass through each section in sequence and finally be output through the fan air supply section 20.

[0029] The fresh air bypass pipe 101 is connected to the return air pipe 6. In the medium-temperature air-conditioned area 8, air is supplied through the supply air pipe 7, return air is supplied through the return air pipe 6, and exhaust air is supplied through the exhaust air pipe 9, thus forming a complete air handling and air circulation system.

[0030] The operating principle of this utility model is as follows:

[0031] 1. Air handling process under heat recovery start-up operation conditions

[0032] In this embodiment, when the heat recovery of the dual-source medium-temperature air conditioning unit 1 with heat recovery is turned on, fresh air enters the air inlet section 10 through the first electric air volume regulating valve V1. At this time, the second electric air volume regulating valve V2 is closed and the third electric air volume regulating valve V3 is open. After the fresh air is filtered by the first coarse filter section 11, it is pre-cooled by the solution circulation heat recovery section 12. After the fresh air is pre-cooled, it is mixed with the primary return air and then passes through the second coarse filter section 14 and the high-efficiency filter section 15. Then it is cooled once by the air conditioning water-cooled coil section 16 at 7 / 12℃, and then cooled twice by the medium-temperature direct expansion refrigeration section 17. Finally, it is reheated by the condenser reheat section 18 to reach the air supply state point. At this time, the air supply temperature is higher than the indoor dew point temperature.

[0033] 2. Principle of switching between different operating conditions

[0034] In practical use, the medium-temperature air-conditioning area 8 is a medium-temperature food processing workshop. The medium-temperature air-conditioning system of this utility model is installed in the medium-temperature food processing workshop, and its operating conditions switch according to different operating seasons. During the operating season of the medium-temperature air-conditioning system, the air-conditioning system of the medium-temperature workshop adopts the minimum fresh air ratio, heat recovery is turned on, and the exhaust fan box 3 with heat recovery is running. Fresh air achieves heat recovery through the solution circulation heat recovery section 12 and the exhaust fan box 3 with heat recovery. During the non-air-conditioning operating season, due to the small temperature difference between the supply and exhaust air, the heat recovery value is low. In order to reduce the resistance of the fresh air and exhaust heat recovery section air system, the fresh air is mixed with the return air through the bypass pipe and does not pass through the heat recovery section. The all-air unit operates with 70% fresh air, and the corresponding exhaust fan unit 4 operates to adapt to the change in fresh air volume. At this time, the all-air unit uses the medium-temperature direct expansion refrigeration section 17 for low-temperature air supply and the condensation reheat section 18 for reheating. The opening and closing status of the switching valve of the medium-temperature air-conditioning unit with heat recovery dual cold source is detailed in Table 3, which shows the opening and closing status of the valve of the heat recovery unit switching operation.

[0035] Table 3. Opening and closing status of valves during heat recovery unit switching operation

[0036]

[0037] 3. Operating principles and applicability in different climate zones

[0038] This invention employs dual-cold-source, two-stage cooling technology and liquid circulation heat recovery technology, which are also applicable to other climate zones. The operating conditions in hot-summer, cold-winter regions are basically the same as those of this invention. However, in cold regions with relatively long transitional seasons, the dual-cold-source, two-stage cooling technology allows for more flexible operation of the cold source. During the transitional season, only the direct expansion section needs to be activated to meet cooling requirements, reducing the time the centralized cold source is on and allowing heat recovery to be shut down. Liquid circulation heat recovery can preheat fresh air in winter. In cold regions, using ethylene glycol liquid circulation can reduce the risk of freezing in the heat recovery circulation pipeline during winter. The energy-saving benefits of heat recovery are significant when there is a large temperature difference between indoors and outdoors in winter.

[0039] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of this invention, and should be understood that the scope of protection of this invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on these technical teachings disclosed in this invention without departing from the essence of this invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply, characterized in that: The system includes a dual-source medium-temperature air conditioning unit with heat recovery (1), an outdoor unit of the direct expansion section (2), an exhaust fan box with heat recovery (3), an exhaust fan unit (4), and a solution circulation pump (5). The dual-source medium-temperature air conditioning unit with heat recovery (1) is connected to the outdoor unit of the direct expansion section (2). The dual-source medium-temperature air conditioning unit with heat recovery (1) is equipped with an air inlet section (10), a first coarse filter section (11), a solution circulation heat recovery section (12), a mixing section (13), a second coarse filter section (14), a high-efficiency filter section (15), an air conditioning water-cooled coil section (16), a medium-temperature direct expansion refrigeration section (17), a condensing reheat section (18), and an air conditioning maintenance section (19). 9) The air supply section (20) and the medium-temperature air conditioning unit (1) with heat recovery dual cold source are connected to the medium-temperature air conditioning area (8) through the return air pipe (6) and the air supply pipe (7); the exhaust fan box (3) with heat recovery is provided with the second air inlet section (30), the third coarse filter section (31), the second air section maintenance section (32), the second solution circulation heat recovery section (33) and the fan section (34) in sequence; the exhaust fan box (3) with heat recovery is connected to the medium-temperature air conditioning area (8) through the exhaust pipe (9); the exhaust fan box (3) with heat recovery is connected to the medium-temperature air conditioning unit (1) with heat recovery dual cold source through the pipe, and the pipe is equipped with a solution circulation pump (5).

2. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply according to claim 1, characterized in that: The air inlet section (10) is connected to a fresh air duct (100). A first electric air volume regulating valve (V1) is provided between the fresh air duct (100) and the air inlet section (10). A fresh air bypass pipe (101) is provided on the fresh air duct (100). A second electric air volume regulating valve (V2) is provided on the fresh air bypass pipe (101). A third electric air volume regulating valve (V3) is provided on the return air duct (6). A first electric second ventilation valve (V4) is provided between the heat recovery exhaust fan box (3) and the exhaust pipe (9). A second electric second ventilation valve (V5) is provided between the exhaust fan unit (4) and the exhaust pipe.

3. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply according to claim 1, characterized in that: The medium-temperature direct expansion refrigeration section (17) and condensing reheat section (18) of the dual-source medium-temperature air conditioning unit (1) with heat recovery are connected to the outdoor unit (2) of the direct expansion section through refrigerant pipes; the solution circulation heat recovery section (12) of the dual-source medium-temperature air conditioning unit (1) with heat recovery is connected to the second solution circulation heat recovery section (33) in the exhaust fan box (3) with heat recovery and connected to the solution circulation pump (5) through the solution circulation pipe.

4. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply according to claim 1, characterized in that: The air conditioning water-cooled coil section (16) of the dual-cold-source medium-temperature air conditioning unit (1) with heat recovery is connected to the centralized air conditioning chilled water supply equipment through the air conditioning supply and return water pipes to perform primary cooling treatment on the air.

5. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply according to claim 1, characterized in that: The air inlet section (10), the first coarse filter section (11), the solution circulation heat recovery section (12), the mixing section (13), the second coarse filter section (14), the high-efficiency filter section (15), the air conditioning water cooling coil section (16), the medium-temperature direct expansion refrigeration section (17), the condensation reheat section (18), the air section maintenance section (19), and the fan air supply section (20) of the air conditioning unit (1) with heat recovery dual cold source are arranged in sequence. The air can pass through each section in sequence and finally be output through the fan air supply section (20).

6. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply according to claim 2, characterized in that: The fresh air bypass pipe (101) is connected to the return air pipe (6).

7. A heat recovery dual-source medium-temperature air conditioning system for low-temperature air supply according to claim 1, characterized in that: The medium-temperature air-conditioned area (8) is supplied with air through the air supply pipe (7), returned with air through the return air pipe (6), and exhausted with air through the exhaust pipe (9), thus forming a complete air treatment and air circulation.

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