Heat exchange system utilizing novel composite material for phase-change heat exchange

Abstract

The invention discloses a heat exchange system utilizing novel composite material phase change heat exchange, which comprises a heat exchanger, a material pipe and two headers for liquid inlet and liquid outlet respectively, the heat exchanger is composed of a plurality of heat exchange units arranged in parallel, each heat exchange unit is communicated with the liquid inlet header and the liquid outlet header through a liquid inlet pipe and a liquid outlet pipe respectively, and the material pipe is connected with the material pipe. A liquid inlet valve and a liquid outlet valve are installed on the two liquid inlet and outlet pipes respectively, a total liquid inlet and a total liquid outlet are designed at each end of the liquid inlet collecting box and the liquid outlet collecting box, the material pipes are inserted into the heat exchange units, the material pipes are connected with the heat exchange units in a sealed mode, a certain amount of heat exchange materials are filled in the material pipes, and the heat exchange materials are composite cold storage or heat storage materials. The heat exchange materials are loaded into the heat exchange units through the material pipes, heat supply or cold supply of the heat exchanger is achieved by replacing the composite heat storage or cold storage materials, the heat exchange units are connected in parallel and mutually independent, liquid flow control is conducted independently, and independence among the heat exchange units is guaranteed.

Description

Technical field:

[0001] The invention belongs to the technical field of heat exchange, and in particular relates to a novel composite material phase change heat exchange system. Background technology:

[0002] With the continuous development of social economy, people's demand for clean energy is gradually increasing, and the difference between peak and valley loads of daily energy consumption is also increasing. Against this background, energy storage technology has developed rapidly. Energy storage technology balances energy supply and demand by shifting peaks and filling valleys, alleviating the contradiction between energy supply and demand. At present, most of the more mature heat storage and cold storage media used in industry and civil applications are liquid water. The commonly used heat exchange system is a liquid tank and its coil or water distributor for heat exchange, which uses the sensible heat storage of liquid water for heat exchange; ice storage technology is also widely used. The equipment for ice storage and cooling is a heat exchange system of phase change materials. The system consists of a cold storage system and a refrigeration unit. General cold storage equipment uses ethylene glycol to melt ice and make ice. The following are the common forms of cold storage and heat exchange devices on the market:

[0003] (1) Ice packaging and ice storage:

[0004] The cold storage medium is encapsulated in a small spherical or plate-shaped container, and a plurality of such small cold storage containers are densely placed in a sealed tank or an open tank body, thereby forming an encapsulated ice storage device;

[0005] (2) Coil ice storage:

[0006] The ice coil type cold storage device is an ice storage device that consists of a coil immersed in a water tank to form a heat exchange surface. When storing cold, the coolant passes through the tube and ice freezes outside the tube.

[0007] Completely frozen

[0008] The low-temperature ethylene glycol liquid water solution produced by the liquid water chiller is sent to the coil in the ice storage tank to release the cold and make ice. When the ice melts, the inside of the tube is replaced by the frozen liquid water and then returns to the liquid water.

[0009] (4) Dynamic ice making

[0010] Repeated ice making and ice harvesting on the surface of the plate evaporator;

[0011] (5) Ice hockey type, the container is in the form of a sphere, a flat plate, etc.

[0012] It can be seen that the storage side of the above devices all uses phase change materials placed on one side of the large space of the heat exchanger or plate exchanger to achieve greater cold storage capacity. However, this method is not flexible in load regulation. The larger the space, the more difficult it is to fully utilize the latent heat of the phase change material, which will also affect the energy supply effect and increase energy consumption.

[0013] The present invention provides a heat exchange system that utilizes a new composite material phase change heat exchange. The system uses a phase change material in which the liquid hydrate is an inorganic salt. The phase change material has the advantages of high latent heat value, good thermal conductivity, and convenient adjustment of phase change temperature. The composite phase change material developed and produced by us overcomes the defects of common materials on the market, such as phase separation and high supercooling. For our composite phase change material, the research and development and design of a new heat exchange system that matches it has also become a hot topic. However, so far, there is no composite phase change heat exchange system on the market that can be widely promoted and applied. Summary of the invention:

[0014] The purpose of the present invention is to provide a heat exchange system using a new composite material for phase change heat transfer. By improving the thermal conductivity of the composite material through research and development, the heat exchange efficiency of the heat exchange system can be improved.

[0015] The present invention relates to a heat exchange system utilizing phase change heat exchange of novel composite materials, comprising a heat exchanger, a material pipe, and two headers for liquid inlet and liquid outlet, respectively. The heat exchanger is composed of a plurality of heat exchange units arranged in parallel, each of which is connected to a liquid inlet header and a liquid outlet header through a liquid inlet pipe and a liquid outlet pipe, respectively, a liquid inlet valve and a liquid outlet valve are respectively installed on the two liquid inlet and outlet pipes, a total liquid inlet and a total liquid outlet are designed at each end of the liquid inlet header and the liquid outlet header, the material pipe is inserted into the heat exchange unit, the material pipe is sealed and connected to the heat exchange unit, a certain amount of heat exchange material is filled in the material pipe, and the heat exchange material is a composite cold storage or heat storage material.

[0016] Furthermore, the heat exchange system of the novel composite material phase change heat exchange comprises a circulating liquid pipe, a circulating liquid valve and a circulating liquid pump. One end of the circulating liquid pipe is connected to the liquid outlet manifold near the total liquid outlet, and the other end is near the total liquid inlet and connected to the liquid inlet manifold. The circulating liquid valve and the circulating liquid pump are designed and installed in sequence on the circulating liquid pipe.

[0017] Furthermore, the heat exchange unit is composed of a heat exchanger box, a baffle, a liquid distribution plate and a material pipe. The liquid inlet and outlet pipes are respectively installed at the upper positions on the left and right sides of the heat exchanger box. A plurality of horizontally arranged liquid distribution plates are fixed in sequence from top to bottom inside the heat exchanger box at equal intervals. The liquid distribution plates are designed with evenly distributed liquid flow holes. There are also a plurality of vertically arranged baffles, which are fixed in sequence from left to right inside the heat exchanger box at equal intervals. Two adjacently installed baffles have a liquid flow channel set between one and the plate in front of the heat exchanger box, and similarly, a liquid flow channel is set between the other and the plate in the back of the heat exchanger box. The liquid distribution plates and baffles are designed to be cross-connected to divide the heat exchanger box into a number of cells. A hole consistent with the outer diameter of the material pipe is designed on the liquid distribution plate of each cell. Correspondingly, holes of the same specification are designed on the side panels of the heat exchanger box, and the material pipe is inserted into the corresponding holes and fixed.

[0018] Furthermore, the cover of the material pipe is designed to be exposed outside the heat exchanger box, and a detection hole for detecting temperature is designed on the cover of the material pipe, so that the temperature in each material pipe can be detected, and temperature sensors are designed and installed on the liquid inlet pipe and the liquid outlet pipe.

[0019] Furthermore, a total liquid inlet and a total liquid outlet are designed at each end of the liquid inlet and outlet manifolds, and valves for controlling the inflow and outflow of liquid are installed at the two total liquid inlets and outlets.

[0020] Compared with the existing technologies on the market, the system of the present invention has the following beneficial effects: (1) The heat exchange material is a new composite material and is injected into the heat exchanger unit through a detachable material pipe. The heat exchanger can provide heating or cooling by replacing the composite heat storage or cold material; (2) The heat exchange units are connected in parallel and are independent of each other. The liquid flow rate is controlled independently by their respective inlet and outlet valves. The heat exchange units are independent of each other. In case a heat exchange unit fails, the corresponding inlet and outlet valves at both ends of the heat exchange unit are turned off, which makes disassembly and assembly convenient and does not affect the overall operation of the heat exchanger; (3) The cold storage or heat storage material has a very high thermal conductivity and latent heat value. According to the size of the cold storage or heat storage load, the purpose can be achieved by adjusting the diameter and number of the material pipe. Description of the drawings:

[0021] Figure 1 The present invention is a schematic diagram of the plan layout of a heat exchange system for phase change heat transfer of a novel composite material.

[0022] Figure 2 The figure is a schematic diagram of the internal structure of the heat exchanger system involved in the present invention. Specific implementation method:

[0023] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Furthermore, if Figure 1 As shown, the present embodiment involves a heat exchange system utilizing phase change heat transfer of a novel composite material, comprising a heat exchanger 1, a material pipe 2, an inlet liquid water header 3 and an outlet liquid water header 4. The heat exchanger 1 is composed of a plurality of heat exchange units 5 arranged in parallel, each of which is connected to the inlet liquid header 3 and the outlet liquid header 4 through an inlet pipe 6 and an outlet liquid pipe 7, respectively. An inlet valve 8 and an outlet valve 9 are respectively installed on the two inlet and outlet liquid pipes. A total liquid inlet is designed at one end of the inlet liquid header 3 and the outlet liquid header 4, and a total liquid outlet is designed at the other end. The material pipe 2 is inserted into the heat exchange unit 5, and the material pipe 2 is sealedly connected to the heat exchange unit 5. A certain amount of heat exchange material is filled in the material pipe 2, and the heat exchange material is a composite cold storage or heat storage material.

[0025] The liquid water circulated back from the air-cooled coil for cooling on the user side is driven into the liquid water inlet header 3 through the total liquid water inlet, and is driven into the heat exchange unit corresponding to each liquid water inlet pipe 6 in the liquid water inlet header 3. After heat exchange through close contact with the composite material, it flows out through the liquid water outlet pipe 7 under the action of pressure, and is uniformly merged in the liquid water outlet header 4, and finally flows out through the total liquid water outlet. The function of the liquid water inlet header 3 and the liquid water outlet header 4 is to mix the liquid water flowing into each liquid water inlet pipe 6 or flowing out of each liquid water outlet pipe 7, maintain the uniformity of the liquid water temperature, and maintain the stability of the liquid water flow. In the heat exchanger system, the heat exchange units 5 are connected in parallel, independent of each other, and the liquid flow rate is controlled separately. The liquid water flow rate is controlled separately by the respective inlet and outlet valves 8 and 9, which ensures the independence of each heat exchange unit. When a heat exchanger unit 4 fails, the corresponding inlet and outlet valves 8 and 9 at both ends of the heat exchange unit are turned off, which is convenient for disassembly and assembly, and does not affect the overall operation of the heat exchanger. In addition, the liquid water temperature at the outlet can be adjusted by the number of heat exchange units 5 used in the process. The heat exchange material is filled in each independent material pipe, which is convenient for disassembly and assembly. If a material pipe or the material in the pipe has a problem, the material pipe can be directly replaced by pulling it out from the top.

[0026] Specifically, the components of the novel composite material phase change heat exchange system further include a circulating liquid water pipe 10, a circulating liquid water valve 11 and a circulating liquid water pump 12. One end of the circulating liquid water pipe 10 is connected to the liquid water outlet manifold 4 near the total liquid water outlet, and the other end is connected to the liquid water inlet manifold 3 near the total liquid water inlet. The circulating liquid water valve 11 and the circulating liquid water pump 12 are sequentially installed on the circulating liquid water pipe 10. When the heat exchange is just started or the total outlet liquid water temperature is too low (or too high) to meet the requirements, the circulating liquid water valve 11 can be opened to transport an appropriate amount of outlet liquid water in the circulating liquid water pipe 10 back to the total liquid water inlet through the pipeline to mix with the inlet liquid water, thereby increasing (or decreasing) the liquid water temperature at the inlet, and adjusting the outlet liquid water temperature to meet the user's use requirements. This method can extend the cooling time of the cold storage system.

[0027] Further, according to the attached figure Figure 2As shown, the components of the heat exchange unit of the heat exchange system also include a heat exchanger box 13, a baffle 14, a liquid water distribution plate 15 and a material pipe 2. A liquid inlet pipe 6 and a liquid outlet pipe 7 are respectively installed on the upper part of the left and right sides of the heat exchanger box 13. A plurality of horizontally arranged liquid water distribution plates 15 are fixed in the heat exchanger box 13 from top to bottom at equal intervals. Evenly distributed liquid flow holes are designed on the liquid water distribution plates 15. The even distribution is to avoid funnel-shaped vortices in the process of liquid water flow. A plurality of vertically arranged baffles 14 are fixed in the heat exchanger box 13 from top to bottom at equal intervals. Two adjacently installed baffles 14 are respectively fixed between the front and rear side plates of the heat exchanger box. A gap is left, which is set as a liquid water flow channel, so that the liquid water can flow in an S-shaped route along the length direction of the heat exchanger case. The liquid water distribution plate 15 and the baffle 16 are designed to be cross-connected. This connection method divides the heat exchanger case 13 into a plurality of empty chambers. A mounting hole consistent with the outer diameter of the material pipe is set on the liquid water distribution plate of each empty chamber. Correspondingly, a mounting hole consistent with the outer diameter of the material pipe is also set on the upper side plate of the heat exchanger case 13. The material pipe 2 is inserted into the vertically corresponding (vertically aligned in the figure) mounting hole and fixed. A sealed connection is set at the connection between the material pipe 2 and the side plate of the heat exchanger case 13, so that the liquid water is designed not to flow out from the mounting hole on the case.

[0028] Specifically, a material pipe cover 16 is provided on the outside of the heat exchanger housing 13, and a detection hole for detecting temperature is designed on the material pipe cover 16. The temperature in each material pipe is detected through the detection hole, and it is also convenient to visually observe the use status of the heat exchange material in the material pipe. In addition, temperature sensors are installed on the liquid inlet pipe 6 and the liquid outlet pipe 7 to monitor the actual temperature status of each heat exchange unit during operation in real time.

[0029] The number of the heat exchange units can be calculated based on the building area, the average required cooling and heating loads, the inlet and outlet water temperatures, and the flow rate in the inlet pipe of the heat exchange unit.

[0030] For example: Assuming that the building area to be cooled is 3000m2, the average cooling load required is 120W / m2, the total inlet liquid water temperature is 24℃, theoretically, the average temperature decreases by 1℃ for every two tube bundles, the theoretical value of the liquid water temperature at the outlet of the entire heat exchange unit is 17℃, and the inlet flow rate of the heat exchange unit is 0.2kg / s, then:

[0031] Total cooling capacity: 3000×120=360kJ / s;

[0032] The cooling capacity released by a single heat exchange unit is: W = cmΔt = 4.18 × 0.2 × 7 = 5.852 kJ / s

[0033] The number of heat exchanger units required is: 360 / 5.852≈62. In order to ensure that the liquid water temperature at the heat exchanger outlet can meet the user's requirements, 63 heat exchange units are designed.

[0034] Furthermore, a total liquid inlet and a total liquid outlet are designed at each end of the liquid inlet and outlet manifolds, and valves for controlling the inflow and outflow of liquid are installed at the two total liquid inlets and outlets.

[0035] The present embodiment involves a novel composite material phase change heat exchange system, which utilizes the nighttime off-peak electricity to store cold for materials and uses it for cooling during the daytime peak hours of municipal electricity consumption, thereby achieving the purpose of shifting peaks and filling valleys to reduce electricity consumption, with significant economic, energy-saving and environmental protection benefits.

[0036] The composite material used in this embodiment is a self-developed inorganic phase change cold storage material. Its specific composition and quality are not convenient to be announced for commercial needs. The results of multiple hot and cold cycle experimental tests show that the developed composite inorganic phase change heat storage material has excellent cold storage performance. The heat exchange equipment using this material for cold storage has a high heat transfer coefficient and is also convenient for regulating the cold storage and release rates.

Claims

1. A heat exchange system using a new composite material phase change heat exchange, characterized in that: It includes a heat exchanger, a material pipe, and two manifolds for liquid inlet and liquid outlet respectively. The heat exchanger is composed of a number of heat exchange units arranged in parallel. Each heat exchange unit is connected to the liquid inlet manifold and the liquid outlet manifold respectively through the liquid inlet pipe and the liquid outlet pipe. The liquid inlet valve and the liquid outlet valve are respectively installed on the two liquid inlet and outlet pipes. Each end of the liquid inlet manifold and the liquid outlet manifold is designed with a total liquid inlet and a total liquid outlet. The material pipe is inserted into the heat exchange unit, and the material pipe is sealed and connected to the heat exchange unit. A certain amount of heat exchange material is filled in the material pipe, and the heat exchange material is a composite cold storage or heat storage material.

2. A novel composite material phase change heat exchange system according to claim 1, characterized in that: The heat exchange system comprises a circulating liquid pipe, a circulating liquid valve and a circulating liquid pump. One end of the circulating liquid pipe is connected to the liquid outlet header near the total liquid outlet, and the other end is near the total liquid inlet and connected to the liquid inlet header. The circulating liquid valve and the circulating liquid pump are designed and installed in sequence on the circulating liquid pipe.

3. A novel composite material phase change heat exchange system according to claim 2, characterized in that: The heat exchange unit is composed of a heat exchanger box, a baffle, a liquid distribution plate and a material pipe. The liquid inlet and outlet pipes are respectively installed at the upper positions on the left and right sides of the heat exchanger box. A plurality of horizontally arranged liquid distribution plates are fixed in sequence from top to bottom inside the heat exchanger box at equal intervals. The liquid distribution plates are designed with evenly distributed liquid flow holes. There are also a plurality of vertically arranged baffles, which are fixed in sequence from left to right inside the heat exchanger box at equal intervals. Two adjacently installed baffles have a liquid flow channel set between one and the plate in front of the heat exchanger box, and similarly, a liquid flow channel is set between the other and the plate in the back of the heat exchanger box. The liquid distribution plates and baffles are designed to be cross-connected to divide the heat exchanger box into a number of cells. A hole consistent with the outer diameter of the material pipe is designed on the liquid distribution plate of each cell. Correspondingly, holes of the same specification are designed on the side panels of the heat exchanger box, and the material pipe is inserted into the corresponding holes and fixed.

4. A novel composite material phase change heat exchange system according to claim 3, characterized in that: The cover of the material pipe is designed to be exposed outside the heat exchanger box. A detection hole for detecting temperature is designed on the cover of the material pipe, so that the temperature in each material pipe can be detected, and temperature sensors are designed and installed on the liquid inlet pipe and the liquid outlet pipe.

5. A novel composite material phase change heat exchange system according to claim 4, characterized in that: A total liquid inlet and a total liquid outlet are designed at each end of the liquid inlet and outlet manifolds, and valves for controlling the inflow and outflow of liquid are installed at the two total liquid inlets and outlets.

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