CN102788524A - Multistage power heat pipe system - Google Patents

Abstract

The invention discloses a multi-level power heat pipe system, which mainly consists of a first-level power heat pipe unit, a second-level power heat pipe unit, a third-level power heat pipe unit, an evaporator fan, a condenser fan, a heat exchanger and a circuit control element. It needs to be made into a 4-N level power heat pipe; each level of power heat pipe unit is an independent circulation loop, in which all evaporators are placed side by side, assembled in the air duct of the same shell, and share an evaporator fan. All condensers are arranged side by side, assembled in the air duct of the same shell, and share a condenser fan; thus a multi-stage power heat pipe system is formed, and the refrigerant in each stage of heat pipe is regarded as a constant temperature fluid, then more The heat pipes in each stage can achieve variable temperature effects, and the heat exchange area of each heat exchanger is the same, and the final discharge temperature is close to the ambient temperature, thereby maximizing the utilization rate of heat energy and solving the problem of large heat exchange temperature loss and total heat exchange efficiency of existing heat pipes low problem.

Description

A multi-stage dynamic heat pipe system

technical field

The invention relates to the technical field of heat exchange, in particular to a novel heat pipe heat exchange system, in particular to a multi-stage power heat pipe system in which a plurality of independent power heat pipe devices are connected in parallel.

Background technique

In information equipment rooms and base station buildings, the heat generated by indoor equipment is very large, reaching 200~1000W/m ² . In addition, indoor IT equipment runs 8760h throughout the year, so cooling is required throughout the year in most cases, and its air conditioning consumes a lot of energy, often accounting for 40% to 50% of the overall energy consumption of information equipment rooms and base stations. Traditional computer room air conditioners use compressor cooling to run throughout the year. In fact, in winter or transitional seasons, when the outdoor temperature is lower than the indoor temperature, the outdoor low-temperature air can be used as a cold source to cool the room without a compressor. The heat pipe heat exchanger is a device that uses temperature difference to drive the refrigerant cycle to achieve heat transfer. Because it does not require a compressor, it can transfer heat by virtue of the evaporation and condensation of the refrigerant. It has superthermal conductivity and isothermal characteristics, and is widely used. Used in aerospace, air conditioning, chemical industry, oil refining and other fields. Applying heat pipe heat exchangers to signals where only sensible heat is transferred

In the computer room, the running time of the compression refrigeration air conditioner can be greatly reduced, and the annual energy saving rate can reach 50%.

The applicant's patent application numbers of 201210247844.7, 201210254213.8, 201210257903.9, 201210259692.2 and 201210279193.X patents provide several single-stage single-stage heat pipes for solving the problems of incomplete gas-liquid separation and insufficient circulation power when the current power heat pipe is working. With the heat pipe structure, the discharge temperature of the air outlet is very high, and the heat loss is still large.

The total driving temperature difference of the heat pipe heat exchanger is the indoor and outdoor temperature difference. The constant temperature characteristic of the refrigerant inside the single-stage heat pipe heat exchanger leads to a large heat loss of the heat pipe heat exchange device. Based on the above, this application can increase the number of heat pipe stages to have Changing the intermediate medium with constant temperature characteristics to medium with variable temperature characteristics is an effective way to reduce the loss of heat transfer temperature difference and improve the total heat transfer efficiency. The single-stage heat pipe heat exchanger is changed to a multi-stage form, and the refrigerant in each heat pipe is regarded as a constant temperature fluid, so the multi-stage heat pipe can realize a heat exchange device with a variable temperature effect, and the heat exchange area of each heat exchanger is the same , the final discharge temperature is close to the ambient temperature, thereby maximizing the utilization rate of heat energy.

Now take the same total heat transfer area (same input) of the multi-stage power heat pipe heat exchange system and the single-stage power heat pipe system for analysis, and the heat transfer capacity of the evaporator and condenser (the number of heat transfer units are both NTU) is the same. Assuming that the number of stages of the multi-stage heat pipe heat exchange device is n, and the heat exchange area of each stage heat exchanger is the same, and the number of heat transfer units is NTU/n, then the efficiency of each stage heat pipe heat exchanger is the same, η ₁ = η ₂ = ... = η _n = ε/2, ε = 1- exp(-NTU/n), the total heat transfer efficiency of the multi-stage heat pipe heat exchange device is η = ( n*η ₁ ) /[1+(n -1)*η ₁ ].

That is, by analyzing the efficiency of the multi-stage heat pipe heat exchange device, it can be obtained:

1) When the number of stages n is given and NTU tends to infinity, η ₁ =1/2, the overall heat transfer efficiency η = n / ( n+1 );

2) When the NTU is given and the series n tends to infinity, the overall heat transfer efficiency η = NTU / ( NTU+2 );

3) When the number of stages n and NTU both tend to infinity, the overall heat transfer efficiency η→1.

Through the above analysis, it can be seen that the single-stage heat pipe heat exchanger is changed to a multi-stage form, and in the case of the same overall heat exchange area, the loss of heat exchange temperature difference is reduced and the total heat exchange efficiency is improved.

Contents of the invention

A new type of heat pipe heat exchange device technology provided by the present invention—a multi-stage power heat pipe system is aimed at solving the problems of large heat exchange temperature difference loss and low total heat exchange efficiency when the power heat pipe is working.

In order to solve the problems of the technologies described above, the technical scheme adopted in the present invention is as follows:

A multi-stage power heat pipe system, including a first-stage power heat pipe unit, a second-stage power heat pipe unit, a third-stage power heat pipe unit, an evaporator fan, a condenser fan, a heat exchanger, connecting pipes and circuit control components, which can be made according to needs into 4-N level power heat pipe units; wherein the first-level power heat pipe unit, the second-level power heat pipe unit and the third-level power heat pipe unit are respectively an independent circulation loop, connected in parallel with each other; the first-level power heat pipe unit includes an evaporator , a condenser one, a liquid storage stabilizer one and a circulation pump one; the secondary power heat pipe unit includes an evaporator two, a condenser two, a liquid storage current stabilizer two and a circulation pump two; the three-stage power heat pipe unit Including evaporator 3, condenser 3, liquid storage stabilizer 3 and circulation pump 3; the evaporators of the first-stage power heat pipe unit, the second-stage power heat pipe unit and the third-stage power heat pipe unit are arranged side by side, each with its own The independent input and output terminals are assembled in the same shell and located in the air duct formed by the evaporator fan, sharing one evaporator fan; the condensers of the primary power heat pipe unit, the secondary power heat pipe unit and the tertiary power heat pipe unit Arranged side by side, each has its own independent input and output terminals, assembled in the same shell and located in the air duct formed by the condenser fan, and share a condenser fan.

The evaporators and condensers of the first-stage power heat pipe unit, the second-stage power heat pipe unit and the third-stage power heat pipe unit mentioned above are all heat exchangers or micro-channel heat exchangers composed of coil fins, which have the same structure, and each The first stage heat exchangers have their own input and output ports.

The first-stage power heat pipe unit, the second-stage power heat pipe unit and the third-stage power heat pipe unit mentioned above are all independent circulation loops, they have independent circulation pumps, and their work and operation do not affect each other.

The above-mentioned circuit control components mainly monitor some temperature changes in the high-temperature environment and low-temperature environment through some temperature detection equipment. When the temperature difference between the high-temperature environment end and the low-temperature environment end exceeds a certain value, the circulation pump will be automatically controlled. The system starts to work, when the temperature difference between the high temperature environment end and the low temperature environment end is less than a certain value, it will automatically control the shutdown of the circulation pump, because the working conditions are not met, the system will stop working.

Compared with the prior art, the present invention can change the intermediate medium with constant temperature characteristics into medium with variable temperature characteristics by increasing the design of heat pipe stages to realize an effective way to reduce heat exchange temperature difference loss and improve total heat exchange efficiency. The heat exchange efficiency of each equipment cycle is improved, and the stability of the entire system cycle is realized. The gas-liquid circulation pump added to the system provides operating power for the entire heat pipe system, which also solves the problem of traditional heat pipe system operation. The difference in the height and position of the two heat exchangers and the transportation distance can reduce the restrictions on the use of the equipment, greatly improve the heat exchange efficiency of the heat pipe, and the structure of the entire system is simple and environmentally friendly.

Description of drawings

Fig. 1 is a structural schematic diagram of an embodiment of the system.

Among the figure: (11) primary power heat pipe unit; (12) secondary power heat pipe unit; (13) tertiary power heat pipe unit; (2) evaporator fan; (3) condenser fan; (41) Evaporator one; (42) Evaporator two; (43) Evaporator three; (51) Condenser one; (52) Condenser two; (53) Condenser three; (61) Circulation pump one; (62) Circulation Pump two; (63) circulating pump three; (71) liquid storage and flow stabilizer one; (72) liquid storage and flow stabilization device two; (73) liquid storage and flow stabilization device three.

Detailed ways

The schematic diagram of the simple structure of this embodiment is shown in Figure 1; the main structure of the system device involved in the implementation of this embodiment includes a primary power heat pipe unit (11), a secondary power heat pipe unit (12), and a three-stage power heat pipe unit (13) , evaporator fan (2), condenser fan (3), evaporator one (41), evaporator two (42), evaporator three (43), condenser one (51), condenser two (52), Condenser three (53), circulation pump one (61), circulation pump two (62), circulation pump three (63), liquid storage stabilizer one (71), liquid storage stabilizer two (72), liquid storage Current stabilizer three (73), equipment required for circulation and circuit control components; the whole system can be made into a 4-N level power heat pipe unit according to needs. When the system is working, the circulation pump (61; 62; 63), condenser fan (3) and the evaporator fan (2) are turned on at the same time, and the power units at all levels start to work; when the first-level power heat pipe unit is working, the circulation pump one (61) draws the refrigerant from the liquid storage stabilizer one (71) and sends it to into the evaporator (41), the evaporator (41) is in contact with the high-temperature heat source, the liquid working medium is heated by the high-temperature heat source in the evaporator (41), evaporates into a gas, and absorbs heat, and the gas formed by evaporation and part of it does not The evaporated liquid intermediate medium mixes with each other in high-speed flow to form a gas-liquid two-phase fluid, which enters the condenser (1) from the evaporator (41) through the intermediate conveying device, and the condenser (51) is in contact with a low-temperature heat source and works in a gaseous state The medium is cooled by the low-temperature heat source in the condenser (51), and partly condenses into a liquid refrigerant and releases heat. Driven by the delivery pump (61), the refrigerant enters the liquid storage stable from the condenser (51). In the flow device 1 (71), the gas-liquid refrigeration intermediate medium is separated in the liquid storage stabilizer 1 according to their physical properties, thus completing the entire cycle process of the primary power heat pipe unit (11); the secondary power heat pipe unit ( 12) The cycle mode of the third-stage power heat pipe unit (13) is the same as that of the first-stage power heat pipe unit (11).

In this way, the indoor air exchanges heat with the pipes and cooling fins of the evaporator, the heating temperature of the evaporator (41; 42; 43) goes from high to low along the wind direction, and the temperature of the indoor air also decreases stepwise; the outdoor air and the condenser Through pipes and cooling fins for heat exchange, the heating temperature of the condenser (53; 52; 51) increases from low to high along the wind direction, and the final discharge temperature is close to the ambient temperature, thereby maximizing the utilization rate of heat energy.

After the system is welded and installed, check the system for leaks first. If no leaks are found, vacuumize the system. After vacuuming, add refrigerant to the inside, and the preparatory work of the system is completed.

When the temperature difference between the high-temperature environment end and the low-temperature environment end does not reach the environment required for system operation, the circuit control element shuts down the circulating pump (61; 62; 63) through the signal sent by the temperature detection part, and the system is in a stopped state; When the temperature of the high-temperature environment end is higher than that of the low-temperature environment end by a certain value, the signal is detected by the temperature detection part in the circuit control, and then the control circuit controls the circulation pump (61; 62; 63) to automatically turn on, and the whole system is in normal operation. .

Claims (3)

1. multistage power hot-pipe system; Comprise one-level power heat pipe unit (11), evaporator fan (2), condenser fan (3), heat exchanger and connect pipeline; It is characterized in that; Also comprise second motive force heat pipe unit (12) and three grades of power heat pipe unit (13); Can make 4-N level power heat pipe unit as required, wherein one-level power heat pipe unit (11), second motive force heat pipe unit (12) and three grades of power heat pipe unit (13) all are an independently closed circuit respectively, and are parallel with one another; Said one-level power heat pipe unit (11) comprises evaporimeter one (41), condenser one (51), liquid storage flow straightener one (71) and circulating pump one (61); Said second motive force heat pipe unit (12) comprises evaporimeter two (42), condenser two (52), liquid storage flow straightener two (72) and circulating pump two (62); Said three grades of power heat pipe unit (13) comprise evaporimeter three (43), condenser three (53), liquid storage flow straightener three (73) and circulating pump three (63); The evaporimeter (41 of said one-level power heat pipe unit (11), second motive force heat pipe unit (12) and three grades of power heat pipe unit (13); 42; 43) put side by side each other, the independent input/output terminal of oneself is arranged respectively, be assembled in the same housing and be positioned at the air channel that evaporator fan (2) forms, a shared evaporator fan (2); The condenser (51 of said one-level power heat pipe unit (11), second motive force heat pipe unit (12) and three grades of power heat pipe unit (13); 52; 53) put side by side mutually, the independent input/output terminal of oneself is arranged respectively, be assembled in the same housing and be positioned at the air channel that condenser fan (3) forms, a shared condenser fan (3).

2. a kind of multistage power hot-pipe system according to claim 1 is characterized in that, the evaporimeter (41 of said one-level power heat pipe unit (11), second motive force heat pipe unit (12) and three grades of power heat pipe unit (13); 42; 43) and condenser (51; 52; 53) all be heat exchanger or the micro-channel heat exchanger that the coil pipe fin is formed, its structure is identical, and the heat exchanger of each grade all has input and output port separately.

3. a kind of multistage power hot-pipe system according to claim 1; It is characterized in that; Said one-level power heat pipe unit (11), second motive force heat pipe unit (12) and three grades of power heat pipe unit (13) all are respectively independently closed circuits; They have independently circulating pump, are independent of each other mutually during its work operation.