Ethylene glycol heat recovery system with anti-freezing function

Abstract

The utility model discloses an ethylene glycol heat recovery system with an anti-freezing function, and relates to the technical field of heat recovery of fresh air systems. The ethylene glycol heat recovery system comprises a fresh air side heat recovery coil pipe and an exhaust side heat recovery coil pipe, the fresh air side heat recovery coil pipe and the exhaust side heat recovery coil pipe are communicated through a circulating pipeline to form a circulating loop, and a circulating pump and a two-position three-way electromagnetic valve are further arranged on the circulating pipeline in the circulating loop. The two-position three-way electromagnetic valve is matched with a heat compensation pipe; the heat compensation pipe is connected with the fresh air side heat recovery coil pipe in parallel; and a temperature sensor is arranged on a liquid inlet circulating pipeline of the air exhaust side heat recovery coil pipe. When a temperature sensor detects that a frosting condition is met, a part of ethylene glycol mixed solution which is located in a fresh air liquid supply circulation section and is high in temperature is mixed with an ethylene glycol mixed solution which is located in an exhaust air liquid supply circulation section and is low in temperature, so that the temperature of the ethylene glycol mixed solution entering an inlet of an exhaust air side coil pipe is increased; and the effects of preventing frosting and freezing are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to fresh air system heat recovery technical field, concretely is a kind of glycol heat recovery system with anti-freezing function. BACKGROUND

[0002] Glycol (solution) heat recovery system is a kind of heat recovery type that is more widely used in new fresh air air conditioning project.The system is provided with heat recovery heat exchange coil on new fresh air side and exhaust air side, and is connected by circulating pump in the middle, to transfer the energy recovered from exhaust air to new fresh air side coil for pre-treatment (heating or cooling) of new fresh air, to realize the energy-saving effect of new fresh air air conditioning unit.The heat exchange medium in glycol (solution) heat recovery system is mainly glycol mixed solution.

[0003] As shown in Figure 1 Glycol heat recovery system mainly includes new fresh air side heat recovery coil 13 arranged in the inside of new fresh air air conditioning box 11 and exhaust air side heat recovery coil 17 arranged in the inside of exhaust air air conditioning box 16;new fresh air side heat recovery coil 13 and exhaust air side heat recovery coil 17 are connected in series by circulating pump 19 and connecting pipe and form a heat exchange loop, and mixed solution of glycol and water is added in the loop as heat exchange agent, the air inlet end of new fresh air air conditioning box 11 is provided with new fresh air filter 12 for filtering dust and impurities of new fresh air, new fresh air side fan 15 for leading air to indoor is arranged in new fresh air air conditioning box 11, and exhaust air side fan 18 for leading air to outdoor is arranged in exhaust air air conditioning box 16.

[0004] In summer working condition, the cold air in indoor is exchanged heat with the surface of exhaust air side heat recovery coil 17, to reduce the temperature of heat exchange medium glycol solution in exhaust air side heat recovery coil 17, and circulating pump 19 pressurizes and transports heat exchange agent to new fresh air side heat recovery coil 13, at this time, the temperature of new fresh air is reduced after heat exchange with the surface of new fresh air side heat recovery coil 13, the temperature of heat exchange agent in new fresh air side heat recovery coil 13 is increased, and the heat exchange agent with increased temperature flows into exhaust air side heat recovery coil 17 again under the action of circulating pump 19 and exchanges heat with indoor exhaust air, to complete a cold recovery cycle.

[0005] In winter working condition, the hot air in indoor is exchanged heat with the surface of exhaust air side heat recovery coil 17, to increase the temperature of heat exchange medium glycol solution in exhaust air side heat recovery coil 17, and circulating pump 19 pressurizes and transports heat exchange agent to new fresh air side heat recovery coil 13, at this time, the temperature of new fresh air is increased after heat exchange with the surface of new fresh air side heat recovery coil 13, the temperature of heat exchange agent in new fresh air side heat recovery coil 13 is reduced, and the heat exchange agent with reduced temperature flows into exhaust air side heat recovery coil 17 again under the action of circulating pump 19 and exchanges heat with indoor exhaust air, to complete a heat recovery cycle.

[0006] In winter, when the outdoor temperature is lower than -5 DEG C in the cold northern region, the medium outlet temperature of the fresh air side heat recovery coil 13 is lower than 0 DEG C after the solution in the fresh air side heat recovery coil 13 exchanges heat with the fresh air lower than -5 DEG C, at this time, the exhaust air side heat recovery coil 17 exchanges heat with the indoor exhaust air, and latent heat is generated in the heat exchange process, and the condensed water in the exhaust air is separated out, with the increase of the condensed water amount and the decrease of the medium temperature, the exhaust air side heat recovery coil 17 surface will slowly frost, and the exhaust air will be blocked for a long time, which will cause the exhaust air volume to decrease and the wind resistance to increase, and the system exhaust air will be blocked, which will affect the entire exhaust air room. Practical new type content

[0007] The utility model discloses a kind of ethylene glycol heat recovery systems with anti-freezing function, whether the ethylene glycol mixed solution temperature in heat recovery system reaches frost condition is detected, to control a part of higher temperature ethylene glycol mixed solution located in fresh air liquid supply circulation section mixes with lower temperature ethylene glycol mixed solution located in exhaust air liquid supply circulation section, improve the ethylene glycol mixed solution temperature entering exhaust air side coil inlet, make the temperature of inlet solution always higher than the frost temperature of exhaust air side coil, realize the effect of preventing frost and anti-freezing.

[0008] To achieve the above object, the utility model provides the following technical scheme: a kind of ethylene glycol heat recovery systems with anti-freezing function, including fresh air side heat recovery coil and exhaust air side heat recovery coil, the fresh air side heat recovery coil and exhaust air side heat recovery coil are connected into circulation loop by circulation pipeline, circulation pump and two-position three-way electromagnetic valve are also provided on the circulation pipeline in circulation loop, two-position three-way electromagnetic valve is matched with heat supplement pipe, the heat supplement pipe is connected in parallel with the fresh air side heat recovery coil;Temperature sensor is provided on the liquid inlet circulation pipeline of the exhaust air side heat recovery coil.

[0009] Preferably, heat exchange pipe in series with circulation loop is further included, and the heat exchange pipe is located between heat supplement pipe and exhaust air side heat recovery coil;

[0010] Further including auxiliary heating box, the heat exchange pipe is arranged in the auxiliary heating box, and heating resistance is arranged in the auxiliary heating box.

[0011] Compared with prior art, the utility model has the advantages that:

[0012] 1. The utility model discloses a temperature sensor detects the glycol mixed solution temperature of entering the exhaust side heat recovery coil less than zero degree reaches frost condition, mixes a part of the glycol mixed solution of higher temperature in the fresh air liquid supply circulation section with the glycol mixed solution of lower temperature in the exhaust liquid supply circulation section, improves the glycol mixed solution temperature of entering the exhaust side coil entrance, makes the temperature of entrance solution always higher than the frost temperature of exhaust side coil, realizes the effect of preventing frost and anti -freezing.

[0013] 2. The utility model discloses a supplementary heating box is provided with water or glycol mixed solution, is used for the heat transfer of heating resistance, heating resistance heats and passes through the heat transfer medium in supplementary heating box and transmits heat to the heat exchange pipe, to this increase the temperature of glycol mixed solution in the exhaust liquid supply circulation section, further increases the frost melting anti -freezing effect. ACCOUNT OF DRAWINGS

[0014] Figure 1 It is the structure schematic diagram of prior art's glycol heat recovery system;

[0015] Figure 2 It is the structure schematic diagram of the utility model's glycol heat recovery system;

[0016] Figure 3 It is the setting mode drawing of supplementary heating box, heat exchange pipe and heating resistance of the utility model.

[0017] In the drawing:

[0018] 11-new air conditioning box, 12-new air filter, 13-new air side heat recovery coil, 14-cooler, 15-new air side fan, 16-exhaust air conditioning box, 17-exhaust air side heat recovery coil, 18-exhaust air side fan, 19-circulating pump,

[0019] 21-two three-way electromagnetic valve, 22-temperature sensor, 23-heat supply pipe,

[0020] 31-supplementary heating box, 32-heat exchange pipe, 33-heating resistance. DETAILED DESCRIPTION

[0021] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model and not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0022] For example, Figure 2As shown, a glycol heat recovery system with anti-freezing function comprises a fresh air side heat recovery coil 13 and an exhaust air side heat recovery coil 17, the fresh air side heat recovery coil 13 and the exhaust air side heat recovery coil 17 are connected by a circulating pipeline to form a circulating loop, a circulating pump 19 and a two-position three-way electromagnetic valve 21 are further arranged on the circulating pipeline in the circulating loop, the two-position three-way electromagnetic valve 21 is matched with a heat supplement pipeline 23, and the heat supplement pipeline 23 is connected in parallel with the fresh air side heat recovery coil 13.

[0023] For convenience of description, the circulating pipeline part flowing from the fresh air side heat recovery coil 13 to the exhaust air side heat recovery coil 17 is temporarily named as an exhaust air liquid supply circulating section, and the circulating pipeline part flowing from the exhaust air side heat recovery coil 17 to the fresh air side heat recovery coil 13 is temporarily named as a fresh air liquid supply circulating section.

[0024] In the embodiment, the circulating pump 19 is arranged on the fresh air liquid supply circulating section.

[0025] In the embodiment, the two-position three-way electromagnetic valve 21 is arranged on the fresh air liquid supply circulating section, one solution outlet end of the two-position three-way electromagnetic valve 21 is connected with one end of the heat supplement pipeline 23, and the other end of the heat supplement pipeline 23 is connected in communication with the circulating pipeline of the exhaust air liquid supply circulating section.

[0026] The circulating pipeline (i.e. the exhaust air liquid supply circulating section) of the liquid inlet of the exhaust air side heat recovery coil 17 is provided with a temperature sensor 22, which is used to detect the temperature of the glycol mixed solution in the circulating pipeline of the liquid inlet of the exhaust air side heat recovery coil 17, when the temperature sensor 22 detects that the temperature of the glycol mixed solution is less than 0 degrees Celsius, the valve opening of the two-position three-way electromagnetic valve 21 in communication with the heat supplement pipeline 23 is opened, a part of the glycol mixed solution with higher temperature in the fresh air liquid supply circulating section is mixed with the glycol mixed solution with lower temperature in the exhaust air liquid supply circulating section, the temperature of the glycol mixed solution entering the inlet of the exhaust air side coil is increased, the temperature of the inlet solution is always higher than the frost temperature of the exhaust air side coil 17, so as to prevent frost and anti-freezing.

[0027] Similarly, the detected temperature value fed back by the temperature sensor 22 is used to control the closing of the valve opening of the two-position three-way electromagnetic valve 21 in communication with the heat supplement pipeline 23, for example, the closing signal setting value is set as 5 degrees Celsius, when the temperature sensor 22 detects that the temperature of the glycol mixed solution is greater than 5 degrees Celsius, the valve opening of the two-position three-way electromagnetic valve 21 in communication with the heat supplement pipeline 23 is closed, under the premise of ensuring that the exhaust air side will not frost, it is ensured that the heat recovered in the heat recovery system is all used for heat exchange of the fresh air.

[0028] Further, as shown in FIG. 2, the heat supplement pipeline 23 is connected in parallel with the fresh air liquid supply circulating section. Figure 3As shown, the heat exchange pipe 32 in series with the circulating loop is arranged on the exhaust air liquid supply circulating section and between the heat supplement pipe 23 and the exhaust air side heat recovery coil 17, and the auxiliary heating tank 31 is further arranged, the heat exchange pipe 32 is arranged in the auxiliary heating tank 31, and the heating resistor 33 is arranged in the auxiliary heating tank 31. The auxiliary heating tank 31 is arranged with water or glycol mixed solution for heat transfer of the heating resistor 33, the heating resistor 33 heats and transfers heat to the heat exchange pipe 32 through the heat transfer medium in the auxiliary heating tank 31, so as to increase the temperature of the glycol mixed solution in the exhaust air liquid supply circulating section, and further increase the defrosting and anti-freezing effect.

[0029] Of course, the embodiment also includes a control unit for controlling the two-position three-way electromagnetic valve 21, the temperature sensor 22 and the heating resistor 33, such as an industrial computer, a PLC controller and the like, the above-mentioned control unit belongs to the prior art, and the specific arrangement mode will not be described here.

[0030] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims.

Claims

1. An ethylene glycol heat recovery system with antifreeze function, characterized in that: The heat recovery coil includes a fresh air side heat recovery coil and an exhaust air side heat recovery coil, which are connected by a circulating pipeline into a circulating loop, and a circulating pump and a two-position three-way electromagnetic valve are arranged on the circulating pipeline in the circulating loop, and a heat supplement pipeline is matched with the two-position three-way electromagnetic valve, and the heat supplement pipeline is connected with the fresh air side heat recovery coil in parallel; a temperature sensor is arranged on the circulating pipeline of the exhaust air side heat recovery coil.

2. The ethylene glycol heat recovery system with anti-freezing function according to claim 1, characterized in that: A heat exchange pipeline is further arranged in series with the circulating loop, and the heat exchange pipeline is located between the heat supplement pipeline and the exhaust air side heat recovery coil. An auxiliary heating box is further arranged, the heat exchange pipeline is arranged in the auxiliary heating box, and a heating resistor is arranged in the auxiliary heating box.

Images