Closed type buried pipe fresh air heat exchange system

Abstract

The utility model discloses a closed type buried pipe fresh air heat exchange system which comprises a total heat recovery fresh air machine and a plurality of buried pipe heat exchangers, communicating pipes for connecting the buried pipe heat exchangers in series are buried in an underground foundation, and the buried pipe heat exchangers connected in series form a buried heat exchange module. An air outlet of the total heat recovery fresh air machine is connected with the circulating fan through an air exhaust pipeline, the air exhaust pipeline is connected with an air exchange pipeline, and a fresh air exchange valve is arranged on the air exchange pipeline; an air outlet of the circulating fan is connected with an air inlet of the buried heat exchange module, an air outlet of the buried heat exchange module is connected with the air collection chamber, and the air collection chamber is connected with an exhaust fan of the total heat recovery fresh air machine. The system is ingenious and reasonable in design, the ground source heat energy can be fully utilized by matching the ground heat exchanger with the circulating fan and the total heat recovery fresh air fan, and alternate operation of two working conditions of internal circulation and external ventilation can be realized, so that comfortable and clean air is always provided for the indoor space, and the indoor environment is protected. And a relatively comfortable temperature and humidity state is kept indoors.

Description

Technical Field

[0001] The utility model relates to the technical field of building energy-saving design, in particular to a closed underground pipe fresh air heat exchange system. Background Art

[0002] Building energy consumption in my country accounts for more than 25% of the total energy consumption of the whole society, and half of the building energy consumption comes from heating, ventilation, air conditioning and related systems. Therefore, the energy consumption of air conditioning has become a hot issue in the current field of building energy conservation. Almost all buildings today use air conditioning systems for air conditioning and ventilation and refrigeration, and their high energy consumption has become a major source of building energy consumption. In addition, while the air conditioning fresh air system creates a good indoor environment, it also brings certain damage to the external environment. How to use renewable energy to reduce indoor temperature has become a hot issue in fresh air.

[0003] According to the underground temperature changes, the earth's crust is often divided into the following four geothermal zones: (1) Diurnal temperature change zone: The temperature in this zone is affected by the daily temperature, and its variation depth range is generally no more than 1m; (2) Annual temperature change zone: The temperature in this zone is affected by seasonal temperature changes, and its depth range is generally no more than 20m; (3) Constant temperature zone: At a depth below 20m, it is not affected by seasonal temperature changes; (4) Geothermal warming zone: Below the constant temperature zone, due to the influence of the earth's internal heat, the stratum temperature increases with the increase of burial depth. From the distribution of geothermal zones, in summer, the soil around the buried pipes pre-buried to a certain depth can be used as a cold source to cool the fresh air, and in winter, the soil around the buried pipes pre-buried to a certain depth can be used as a heat source to preheat the fresh air, which can reduce the energy consumption of air conditioning.

[0004] The patent document of our company with publication number CN219797388U discloses an energy-saving prefabricated building system, including a geothermal collector and a geothermal distribution system. The geothermal collector is buried in the foundation of the basement and extends longitudinally into the deep soil. In this case, the geothermal collector is used to exchange energy between the air in the basement and the deep soil, and the geothermal distribution system is used to concentrate the air after energy exchange and distribute it to the fresh air system of the above-ground building. In this way, the soil energy can be effectively used as a cold source to cool the fresh air in summer, and the soil energy can be effectively used as a heat source to preheat the fresh air in winter, thereby effectively reducing the energy consumption of air conditioning. However, the fresh air circulation design in this case is not reasonable enough, and the operating conditions cannot be switched. As a result, as the system operation time increases, the indoor temperature and humidity cannot always be kept in a good and comfortable state. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a closed underground pipe fresh air heat exchange system which has a reasonable design and can automatically switch between different working conditions, thereby always keeping the room in a good and comfortable state.

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a closed underground pipe fresh air heat exchange system, including a full heat recovery fresh air fan installed indoors and a plurality of underground pipe heat exchangers buried in the underground foundation and extending longitudinally into the deep soil, the full heat recovery fresh air fan is provided with an air supply port and a return air port located indoors and a fresh air inlet and an exhaust port located outdoors, the fresh air inlet is connected to the air supply fan of the full heat recovery fresh air fan; a connecting pipe is also buried in the underground foundation to connect the underground pipe heat exchangers in series, each in series The underground pipe heat exchangers together constitute an underground heat exchange module; the exhaust port is connected to the air inlet of the circulation fan through an exhaust duct, the exhaust duct is connected to an air exchange duct, and a fresh air ventilation valve is arranged on the air exchange duct; the air outlet of the circulation fan is connected to the air inlet of the underground heat exchange module, the air outlet of the underground heat exchange module is connected to the air collecting chamber, the return air port is also connected to the air collecting chamber through a return air duct, a check valve is arranged on the return air duct, and the air collecting chamber is connected to the exhaust fan of the full heat recovery fresh air fan.

[0007] As a preferred technical solution, the buried pipe heat exchanger includes a steel pipe pile, a heat-conducting fin is arranged on the outer peripheral wall of the steel pipe pile, and a partition is arranged in the inner cavity of the steel pipe pile, and the partition divides the inner cavity of the steel pipe pile into an air inlet chamber and an air outlet chamber, and the bottoms of the air inlet chamber and the air outlet chamber are connected.

[0008] As a preferred technical solution, the heat-conducting fins are designed in a sheet or spiral shape.

[0009] As a preferred technical solution, the outer side of the connecting pipe is coated with a thermal insulation layer.

[0010] Due to the adoption of the above technical scheme, the utility model has at least the following beneficial effects: the structural design is ingenious and reasonable, and the ground source thermal energy can be fully utilized by means of the buried pipe heat exchanger in conjunction with the circulating fan and the full heat recovery fresh air fan, and the alternating operation of the two working conditions of internal circulation and external ventilation can be realized, thereby always providing comfortable and clean air for the room, so that the room maintains a more comfortable temperature and humidity state. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following drawings are only intended to illustrate and explain the present invention, and do not limit the scope of the present invention.

[0012] Figure 1 It is a system schematic diagram of an embodiment of the utility model;

[0013] Figure 2 It is a structural schematic diagram of the underground pipe heat exchanger in the embodiment of the utility model;

[0014] Figure 3 It is a structural schematic diagram of the underground heat exchange module. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with the accompanying drawings and examples. In the following detailed description, only certain exemplary embodiments of the present invention are described by way of illustration. Needless to say, those skilled in the art will recognize that the described embodiments may be modified in various ways without departing from the spirit and scope of the present invention. Therefore, the drawings and descriptions are illustrative in nature and are not intended to limit the scope of protection of the claims.

[0016] like Figure 1 As shown, the closed underground pipe fresh air heat exchange system comprises a full heat recovery fresh air fan 1 installed indoors and a plurality of underground pipe heat exchangers 2 buried in the underground foundation and extending longitudinally into the deep soil. The full heat recovery fresh air fan 1 is provided with an air supply port 3 and an air return port 4 located indoors and a fresh air inlet 5 and an air exhaust port 6 located outdoors. The fresh air inlet 5 is connected to the air supply fan of the full heat recovery fresh air fan 1; a connecting pipe 7 is also buried in the underground foundation to connect the underground pipe heat exchangers 2 in series, and the underground pipe heat exchangers 2 connected in series form an underground Heat exchange module; the exhaust port 6 is connected to the air inlet of the circulation fan 9 through the exhaust duct 8, the exhaust duct 8 is connected to the air exchange duct 10, and the air exchange duct 10 is provided with a fresh air ventilation valve 11; the air outlet of the circulation fan 9 is connected to the air inlet of the underground heat exchange module, the air outlet of the underground heat exchange module is connected to the air collecting chamber 12, the return air port 4 is also connected to the air collecting chamber 12 through the return air duct, the return air duct is provided with a check valve 13, and the air collecting chamber 12 is connected to the exhaust fan of the full heat recovery fresh air fan 1.

[0017] refer to Figure 2 The buried pipe heat exchanger 2 includes a steel pipe pile 201, and a heat-conducting fin 202 is arranged on the outer peripheral wall of the steel pipe pile 201. The heat-conducting fin 202 is preferably designed in a spiral shape. The steel pipe pile 201 can effectively play a role in the anti-floating of the foundation, and the spiral heat-conducting fin 202 design can better improve the anti-floating ability of the pile raft foundation; the inner cavity of the steel pipe pile 201 is provided with a partition 203, and the partition 203 divides the inner cavity of the steel pipe pile into an air inlet chamber 204 and an air outlet chamber 205. The bottoms of the air inlet chamber 204 and the air outlet chamber 205 are connected to form a "U-shaped tube". Reference Figure 3 , multiple steel pipe piles 201 are connected by connecting pipes 7 to form multiple series loops with close friction resistance. Air enters from one side of the partition 203, flows to the bottom connecting part of the steel pipe pile 201, and then flows out through the other side of the partition 203 to enter the next series steel pipe pile 201. After passing through multiple steel pipe piles 201, the entire circulation path of the air flow is lengthened, the contact heat exchange time is increased, and the air flow and the deep soil are heat exchanged. Multiple series loops are connected at the same time to form a parallel loop to increase the ventilation volume.

[0018] The connecting pipe 7 is buried 1.5 meters underground. The connecting pipe is laid after the trenching of the building unit foundation is completed. A thermal insulation layer and a protective layer are made on the outside of the connecting pipe 7 and backfilled together with the foundation.

[0019] This system uses large-leaf spiral steel pipe piles as underground heat exchangers, which are constructed together with the foundation construction. The air circulation in this underground heat exchanger is a closed cycle, which only provides heat (cold) for fresh air. The system has two operating conditions:

[0020] First working condition: the fresh air exchange valve 11 is closed, the circulating fan 9 is turned on, the full heat recovery fresh air fan 1 is turned on, the underground heat exchanger 2 extracts low-grade air from the room, and after heat exchange through multiple groups of underground heat exchangers, the air exchanges energy with the soil, and then the hot (cold) air is sent to the air collecting chamber 12 through the circulating fan 1 (the check valve 13 prevents the air in the underground pipe from entering the room), the full heat recovery fresh air fan 1 transfers the heat of the air in the underground pipe to the fresh air, and then enters the underground heat exchanger again to absorb ground energy and circulate heat exchange; then the full heat recovery fresh air fan 2 sends clean air with appropriate temperature and humidity into the room. Outdoor fresh air is introduced from the fresh air inlet 5, and after pre-cooling (heating) by the full heat recovery fresh air fan 1, the energy of the hot (cold) air is transferred to the fresh air, and the fresh air is sent to various places in the room through the indoor air outlet 3.

[0021] Second working condition: after the first working condition has been running for a period of time, the circulating air has been polluted by carbon dioxide, then the fresh air exchange valve 11 is opened regularly, and the circulating fan 9 is closed in conjunction. At this time, the indoor dirty air is discharged to the outdoor atmosphere through the fresh air exchange valve 11 after heat recovery by the full heat recovery fresh air fan 1 from the return air port 4, while the fresh air is still introduced from the fresh air inlet 5, and after preheating (cooling) by the full heat recovery fresh air fan 1, it is delivered to the room through the air supply port 3. These two working conditions are used in a cycle, and the valve opening and closing and operation interval time are set regularly. In this cycle, comfortable and clean air is always provided to the room, which can keep a more comfortable temperature and humidity state indoors, and can also restore the soil energy around the buried pipe.

[0022] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A closed underground pipe fresh air heat exchange system, comprising a full heat recovery fresh air fan installed indoors and a plurality of underground pipe heat exchangers buried in an underground foundation and extending longitudinally into the deep soil. The full heat recovery fresh air fan is provided with an air supply port and an air return port located indoors and a fresh air inlet and an air exhaust port located outdoors. The fresh air inlet is connected to the air supply fan of the full heat recovery fresh air fan; the characteristics are: A connecting pipe is also buried in the underground foundation for connecting the buried pipe heat exchangers in series, and the buried pipe heat exchangers connected in series constitute an underground heat exchange module; the exhaust port is connected to the air inlet of the circulating fan through an exhaust duct, and the exhaust duct is connected to an air exchange duct, and a fresh air ventilation valve is arranged on the air exchange duct; the air outlet of the circulating fan is connected to the air inlet of the buried heat exchange module, and the air outlet of the buried heat exchange module is connected to the air collecting chamber, and the return air port is also connected to the air collecting chamber through a return air duct, and a check valve is arranged on the return air duct, and the air collecting chamber is connected to the exhaust fan of the full heat recovery fresh air fan.

2. The closed underground pipe fresh air heat exchange system according to claim 1, characterized in that: The buried pipe heat exchanger includes a steel pipe pile, a heat-conducting fin is arranged on the outer peripheral wall of the steel pipe pile, and a partition is arranged in the inner cavity of the steel pipe pile, and the partition divides the inner cavity of the steel pipe pile into an air inlet chamber and an air outlet chamber, and the bottoms of the air inlet chamber and the air outlet chamber are connected.

3. The closed underground pipe fresh air heat exchange system according to claim 2, characterized in that: The heat conducting fins are designed in a sheet or spiral shape.

4. The closed underground pipe fresh air heat exchange system according to any one of claims 1 to 3, characterized in that: The outer side of the connecting pipe is coated with a heat-insulating layer.

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