Anti-freezing fresh air handling unit

Abstract

The utility model discloses an anti-freezing fresh air handling unit which comprises an air inlet section, a primary filter, a medium efficiency filter, a hot water coil pipe A, a middle section, a frequency conversion fan air supply section, a middle section B, a hot water coil pipe section B and a frequency conversion fan section. Wherein the air inlet section, the primary filter, the medium-efficiency filter, the hot water coil pipe A, the middle section and the variable-frequency fan air supply section form a lower-layer box body of the fresh air conditioning box; the middle section B, the hot water coil section B and the frequency conversion fan section form an upper-layer box body of the fresh air conditioning box, and the upper-layer box body and the lower-layer box body are communicated through an electric adjusting air valve and an electric switch air valve; traditional hot water is used as a heat source, other heat source systems do not need to be additionally arranged, the temperature of fresh air entering the hot coil pipe is increased in an air mixing mode, the frost crack risk is fundamentally eliminated, the increase amplitude of initial investment and operation cost is small, and the anti-freezing effect is remarkable.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of fresh air preheating coil, more particularly to a kind of anti-freezing fresh air air conditioning box. BACKGROUND

[0002] In winter, the temperature is very low in northeast China and northwest China, and in some other similar climate areas, fresh air air conditioning system is prone to freeze crack coil under low temperature condition.

[0003] The main reason for the freeze crack of fresh air preheating coil is that the water temperature in the coil is reduced to below 0℃, and the volume is expanded to cause the crack after freezing. The heat exchanger coil is generally provided with multiple internal passages, and an ideal heat exchanger should have consistent length, resistance and heat exchange uniformity of each internal passage. In actual manufacturing, due to the design level of different manufacturers, coil row number, size and other factors, under the condition that the water temperature of each passage is the same, the outlet water temperature and outlet water flow of each passage are difficult to keep consistent. Therefore, it often occurs that even if the supply and return water temperature is significantly above freezing point, the coil is still cracked. This situation usually occurs in the passage with long internal pipe, small water flow and large heat exchange capacity.

[0004] Ethylene glycol solution is often used instead of water solution in engineering to prevent freezing by using lower freezing point of ethylene glycol, but ethylene glycol system has certain corrosion effect on pipe and coil, and after using ethylene glycol, the heat exchange effect of heat exchange coil is greatly reduced, and the heating effect of fresh air is poor. Moreover, ethylene glycol is also a harmful substance to human body, and leakage also has pollution risk. UTILITY MODEL CONTENT

[0005] Therefore, in order to solve the above problems, the utility model provides an anti-freezing fresh air air conditioning box, which belongs to a kind of fresh air air conditioning structure, uses traditional hot water as heat source, does not need to additionally increase other heat source system, adopts air mixing mode to improve the temperature of fresh air entering the hot coil, fundamentally eliminates the risk of freeze crack, and the increase of initial investment and operating cost is small, and the anti-freezing effect is remarkable.

[0006] The utility model discloses a kind of anti-freezing fresh air air conditioning boxes, which are characterized by comprising air inlet section (1), primary filter (2), medium efficiency filter (3), hot water coil A (4), intermediate section (5), frequency conversion fan air supply section (6), intermediate section B (7), hot water coil section B (8) and frequency conversion fan section (9). The lower box of the fresh air air conditioning box is composed of air inlet section (1), primary filter (2), medium efficiency filter (3), hot water coil A (4), intermediate section (5) and frequency conversion fan air supply section (6). The upper box of the fresh air air conditioning box is composed of intermediate section B (7), hot water coil section B (8) and frequency conversion fan section (9). The upper box and the lower box are connected by electrically adjustable air valve (10) and electrically switchable air valve (11). The air inlet section (1) of the lower box is connected to the outside through the external wall louver air inlet (14) and the fresh air suction duct (15), and the treated fresh air is sent to the air conditioning area through the fresh air supply duct (16). The hot water supply pipe connected to the hot water coil A (4) and the hot water coil section B (8) is sequentially provided with a butterfly valve, a filter and a butterfly valve. The hot water return pipe connected to the hot water coil is sequentially provided with a butterfly valve, an electrically adjustable water valve and a butterfly valve. The return pipe is additionally provided with a bypass pipe, and the bypass pipe is provided with a butterfly valve.

[0007] According to the anti-freezing fresh air air conditioning box, the temperature sensor T1 is arranged in the fresh air suction duct (15) to measure the outdoor temperature. The temperature sensor T2 is arranged in the air inlet section (1) to measure the mixed air temperature after the outdoor fresh air and the air supply of the upper box. The temperature sensor T3 is arranged in the intermediate section (5) to measure the temperature after the hot water coil A (4).

[0008] According to the anti-freezing fresh air air conditioning box, the differential pressure sensor P1 is arranged in the main pipe of the fresh air supply duct (16) to control the frequency of the frequency conversion fan in the frequency conversion fan air supply section (16), so that the air supply amount of the fresh air air conditioning box is maintained at a set value. The differential pressure sensor P2 is arranged in the intermediate section B (7) to control the frequency of the frequency conversion fan in the frequency conversion fan section (9), so that the air volume of the upper box is maintained at a set value.

[0009] The anti-freezing fresh air air conditioning box provided by the utility model belongs to a fresh air air conditioning structure, uses traditional hot water as a heat source, does not need to additionally increase other heat source systems, adopts a mixed air method to increase the temperature of fresh air entering the hot coil, fundamentally eliminates the risk of freeze cracking, and the initial investment and the increase in operating costs are both relatively small, and the anti-freezing effect is remarkable. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 It is the schematic diagram of the implementation structure of the present application.

[0011] Wherein: 1 is the air inlet section; 2 is the primary filter; 3 is the intermediate filter; 4 is the hot water coil A; 5 is the intermediate section A; 6 is the variable frequency fan air supply section; 7 is the intermediate section B; 8 is the hot water coil section B; 9 is the variable frequency fan section; 10 is the electric switch air valve; 11 is the electric switch air valve; 12 is the electric regulating water valve A; 13 is the electric regulating water valve B; 14 is the external wall louver air outlet; 15 is the fresh air suction pipe; 16 is the fresh air supply pipe. Specific embodiments

[0012] The following will be combined with the attached Figure 1 The present utility model will be described in detail. The technical solutions in the embodiments of the present utility model are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0013] The present utility model provides an anti-freezing fresh air air handling unit here, as Figure 1 shown, and it can be implemented in the following manner; it includes an air inlet section 1, a primary filter 2, an intermediate filter 3, a hot water coil A 4, an intermediate section 5, a variable frequency fan air supply section 6, an intermediate section B 7, a hot water coil section B 8, and a variable frequency fan section 9. Among them, the air inlet section 1, the primary filter 2, the intermediate filter 3, the hot water coil A 4, the intermediate section 5, and the variable frequency fan air supply section 6 constitute the lower layer box body of the fresh air air handling unit, and the intermediate section B 7, the hot water coil section B 8, and the variable frequency fan section 9 constitute the upper layer box body of the fresh air air handling unit. The upper layer box body and the lower layer box body are connected through an electric regulating air valve 10 and an electric switch air valve 11. The air inlet section 1 of the lower layer box body is connected to the outside through an external wall louver air outlet 14 and a fresh air suction pipe 15, and the processed fresh air is sent to the air conditioning area through a fresh air supply pipe 16. The hot water supply pipes of the hot water coil A 4 and the hot water coil section B 8 are connected to the hot water supply pipeline. A butterfly valve, a filter, and a butterfly valve are sequentially arranged on the hot water supply pipe connected to the hot water coil; a butterfly valve, an electric regulating water valve, and a butterfly valve are sequentially arranged on the hot water return pipe connected to the hot water coil. Another bypass pipeline is provided on the return pipe, and a butterfly valve is arranged on the bypass pipeline. Except that the butterfly valve on the bypass pipeline is in a normally closed state, other butterfly valves are in a normally open state. When the filter and the electric regulating water valve are damaged, the normally open butterfly valves are closed for maintenance. When the diameter of the hot water connection pipe <DN65, the butterfly valve is changed to a globe valve.

[0014] A temperature sensor T1 is arranged in the fresh air suction pipe 15 for measuring the outdoor temperature, a temperature sensor T2 is arranged in the air inlet section 1 for measuring the mixed air temperature after the outdoor fresh air and the air supply from the upper layer box body, and a temperature sensor T3 is arranged in the intermediate section 5 for measuring the temperature after the hot water coil A 4.

[0015] When the temperature sensor T1 measures the outdoor temperature higher than 0℃, the electric switch air valve 10 and the electric switch air valve 11 are closed, the variable frequency fan section 9 is closed, the electric regulating water valve 13 on the hot water coil section B8 backwater pipe is closed, that is, the upper box does not work, only the lower box works. The electric regulating water valve 12 automatically adjusts the opening degree to maintain T3 at the set value.

[0016] When the temperature sensor T1 measures the outdoor temperature lower than 0℃, the electric switch air valve 10 and the electric switch air valve 11 are opened, the variable frequency fan in the variable frequency fan section 9 is opened, the temperature in the air inlet section 1 is increased to above 0℃ by mixing high temperature air. When the temperature T2 cannot be maintained above 0℃ by direct air mixing, the electric regulating water valve 13 on the hot water coil section B8 backwater pipe is opened, and the opening degree of the electric regulating water valve 13 is controlled by the temperature sensor T2 to maintain the temperature T2 greater than 0℃.

[0017] The differential pressure sensor P1 is arranged in the main pipe of the fresh air supply pipe 16, the frequency of the variable frequency fan in the variable frequency fan supply section 16 is controlled by the differential pressure sensor P1, and the air supply of the fresh air conditioning box is maintained at the set value. The differential pressure sensor P2 is arranged in the intermediate section B7, the frequency of the variable frequency fan in the variable frequency fan section 9 is controlled by the differential pressure sensor P2, and the air volume of the upper box is maintained at the set value.

[0018] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A freeze protection fresh air air conditioning unit, characterized by; It comprises an air inlet section (1), a primary filter (2), a medium filter (3), a hot water coil A (4), an intermediate section (5), a variable frequency fan air supply section (6), an intermediate section B (7), a hot water coil section B (8) and a variable frequency fan section (9); The lower box of the fresh air air conditioning box is composed of the air inlet section (1), the primary filter (2), the medium filter (3), the hot water coil A (4), the intermediate section (5) and the variable frequency fan air supply section (6); The upper box of the fresh air air conditioning box is composed of the intermediate section B (7), the hot water coil section B (8) and the variable frequency fan section (9), and the upper box and the lower box are communicated through the electric regulating air valve (10) and the electric on-off air valve (11); the air inlet section (1) of the lower box is communicated with the outside through the external wall louver air inlet (14) and the fresh air suction duct (15), and the treated fresh air is sent to the air conditioning area through the fresh air supply duct (16); the hot water supply duct connected to the hot water coil A (4) and the hot water coil section B (8) is provided with a butterfly valve, a filter and a butterfly valve in sequence on the hot water supply pipe connected to the hot water coil; a butterfly valve, an electric regulating water valve and a butterfly valve are provided in sequence on the hot water return pipe connected to the hot water coil, and a bypass pipe is additionally provided on the return pipe, and a butterfly valve is provided on the bypass pipe.

2. The freeze protection fresh air air conditioning unit of claim 1, wherein; A temperature sensor T1 is arranged in the fresh air suction duct (15) to measure the outdoor temperature, a temperature sensor T2 is arranged in the air inlet section (1) to measure the mixed air temperature after the outdoor fresh air and the air supply of the upper box, and a temperature sensor T3 is arranged in the intermediate section (5) to measure the temperature after the hot water coil A (4).

3. The freeze protection fresh air air conditioning unit of claim 1, wherein; A differential pressure sensor P1 is arranged in the fresh air supply duct (16) to control the frequency of the variable frequency fan in the variable frequency fan air supply section (16), so that the air supply of the fresh air air conditioning box is maintained at a set value; a differential pressure sensor P2 is arranged in the intermediate section B (7) to control the frequency of the variable frequency fan in the variable frequency fan section (9), so that the air volume of the upper box is maintained at a set value.

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